Have you got a question of connecting to networks of central heat supply? This article is for you: what types of thermal networks are, from which this communication is, which organizations and why are the most suitable for the development of the project and what can sometimes be saved, read right now.
Briefly about thermal networks
What a mixture is imagined by many, but for a more affordable story, several capital truths should be reminded.
First, the heating network does not apply hot water Directly in batteries. The temperature of the coolant in the main pipeline during the coldest days can reach 150 degrees and its direct, in the heating radiator is fragmented by burns and is dangerous to human health.
Secondly, the coolant from the network in most cases should not fall into the hot water supply system of the building. This is called a closed DHW system. To meet the needs of the bathroom and kitchen, drinking water is used (from the water pipeline). She passed disinfecting, and the coolant only provides heated to a certain temperature of 50-60 degrees through a contactless heat exchanger. The use of network water from thermal pipelines in the GWS system is at least wasteful. Coolant prepare on the source of heat supply (boiler room, CHP) by chemical water purification. Due to the fact that the temperature of this water is often higher than the boiling point, it is mandatory to be removed by the solids of rigidity that cause scale. The formation of any deposits on the nodes of the pipeline can derive equipment. Water water It does not heat up to such a degree and, therefore, expensive desalination does not pass. This circumstance and influenced the fact that open gVS systems, with direct watersubor, almost nowhere apply.
Types of heat networks
Consider the types of gaskets of heat networks in the number of pipelines laid nearby.
2-pipe
This network includes two lines: feed and reverse. Preparation of the final product (reducing the temperature of the heat carrier for heating, heated drinking water) It occurs directly in the heat supply building.
3-pipe
Such a type of gasket heat networks is used quite rarely and only for buildings, where the heat interruptions are not allowed, for example, hospitals or kindergartens with a permanent stay of children. In this case, the third line is added: the reserve of the feed pipeline. The unpopularity of this method of reservation is its high cost and impracticality. The laying of an extra pipe easily replaces the installed stationary modular boiler room and the classic 3rd pipe option today is practically not found.
4-pipe
The type of gasket when the consumer is served and the coolant, and the hot water of the water supply system. This is possible in the case of connecting the building to distribution (intra-quartered) networks after the central thermal point, in which drinking water is heated. The first two lines, as in the case of the 2-pipe gasket, is the feed and coolant feed, the third is the feed of hot drinking water, the fourth return it. If they focus on diameters, then 1 and 2 pipes will be the same, the 3rd can differ from them (depends on the consumption), and the 4th is always less than 3rd.
Others
In the operated networks there are other types of gaskets, but they are no longer connected with functionality, but with deformities of the design or unforeseen additional building area. So, with incorrect definition of loads, the proposed diameter can be significantly understated and the need to increase bandwidth appear in the early stages of operation. In order not to shift the entire network again, another pipeline is reported, larger diameter. In this case, the feed goes on one line, and the return on two or vice versa.
When building a thermal network to a conventional building (not the hospital, etc.), either the option of a 2-pipe gasket or a 4-tube is used. It only depends on what networks you were given a punch point.
Existing methods for gasket heat
Overhead
The most favorable way in terms of operation. All defects are not even a specialist, no additional control system is required. There is also a disadvantage: it can be quite rarely used outside the industrial zone - spoils the architectural appearance of the city.
Underground
This type of gasket can be divided into another three varieties:
Channel (heating in the tray).
Pros: Protection against external influence (for example, from damage to the bucket of the excavator), safety (with a fit of pipes, the soil will not be washed out and its failures are excluded).
Minuses: The cost of installation is large enough, with poor waterproofing, the channel is filled with soil or rainwater, which adversely affects the durability of metal pipes.
Babeless (pipeline puts directly into the soil).
Pros: Relatively low cost, simplicity of installation.
Minuses: When the pipeline is ruptured there is a danger of soared the soil, it is difficult to determine the place of gap.
In the sleeves.
Used to neutralize vertical pipes on pipes. It is mainly necessary when crossing roads at an angle. It is a pipeline of a thermal network, laid inside the pipe of a larger diameter.
The choice of method of laying depends on which area the pipeline passes. Optimal in cost and labor costs is a disabled option, but it is not possible to apply it everywhere. If the section of the heating system is located under the road (does not intersect it, but passes in parallel under the roadway) uses the channel gasket. For convenience, it is necessary to use the location of the network under drives only in the absence of other options, since when the defect is detected, it will be necessary to open the asphalt, stop or limit the movement along the street. There are places where the channel device is used to enhance security. This is necessary when laying a network in the territories of hospitals, schools, kindergartens, etc.
The main elements of the thermal network
The thermal network, which species does not consider it, in essence the set of elements collected in the long pipeline. They are produced by industry in the finished form, and the construction of communication comes down to laying and connecting parts with each other.
The pipe is a basic brick in this designer. Depending on the diameter, they are produced by a length of 6 and 12 meters, but at the order at the factory manufacturer can be purchased any meter. Adhere to recommended, oddly enough, it is standard sizes - Factory cutting will cost an order of magnitude more expensive.
For the most part, steel pipes coated with a layer of insulation are used for heatpets. Non-metallic analogues are rarely used and only on networks with a highly reduced temperature schedule. This is possible after the central thermal points or when the source of heat supply is a low-power water-heating boiler room, and it is not always.
For the heat network, it is necessary to use exceptionally new pipes, the reapplication of the used parts leads to a significant reduction in the life. Such savings on materials leads to significant traits for subsequent repairs and fairly early reconstruction. It is undesirable to use for a heating industry of any type of pipe gasket with a spiral weld. Such a pipeline is very laborious in repairs and reduces the rate of emergency elimination of the impulses.
Out of 90 degrees
In addition to ordinary straight pipes, the industry produces and shaped details for them. Depending on the chosen type of pipeline, they can be varied by quantity and purpose. In all embodiments, there are always taps (turns of the pipe at an angle of 90, 75, 60, 45, 30 and 15 degrees), tees (branches from the main pipe, which is welded into it the pipe of the same or smaller diameter) and transitions (change in the diameter of the pipeline). The rest, for example, the terminal elements of the system of operational remote control are issued as needed.
Retracting from the main network
No less important element in the construction of heating mains - shut-off valves. This device overlaps the flow of the coolant, both to the consumer and from it. The lack of shut-off reinforcement on the subscriber's network is unacceptable, since when an accident in the site will have to turn off not only one building, but the entire neighboring area.
For air laying of the pipeline, it is necessary to provide activities that exclude any possibility of unauthorized access to the control parts of the cranes. In case of accidental or intentional closure or restricting the bandwidth of the return pipeline, an invalid pressure will be created, the result of which will not only bring the pipes of the thermal network, but also the heating elements of the building. The most dependent on the pressure of the battery. And new design solutions Radiators are buried much earlier than their Soviet cast-iron fellows. The consequences of the burst battery are not difficult - the premises filled with boiling water require pretty decent amounts for repairs. To eliminate the possibility of controlling fittings, unauthorized people can be provided for drawers with locks closing the control bodies or removable steering.
For underground strip Pipelines to fittings, on the contrary, it is necessary to provide access to the service personnel. For this, heat chambers are constructed. Going down in them, workers can produce the necessary manipulations.
With a chambling laying pre- isolated pipes Armature looks different from its standard species. Instead of the control steering wheel, the ball valve has a long rod, at the end of which the control element is located. Closing / opening occurs with the T-shaped key. It is supplied by the manufacturer's manufacturer complete with the main order for pipes and fittings. For the organization of access, this stem is placed in concrete well And close the hatch.
Shut-off reinforcement with gearbox
On small diameter pipelines, it is possible to save on reinforced concrete rings and hatches. Instead of the progress of the stocks can be placed in metal carcourses. They look like a pipe with the covered cap, mounted on a small concrete pillow and buried to the ground. Quite often, designers on small diameters of pipes are offered to place both row of reinforcement (feed and return pipelines) in one reinforced concrete well with a diameter of 1 to 1.5 meters. This solution looks good on paper, in practice, this location often leads to the impossibility of managing reinforcement. This is due to the fact that both rods are not always located right under the hatch, therefore, set the key vertically to the control element is not possible. The reinforcement for pipelines of the middle and above diameter is equipped with a gearbox or electric drive, it will not be placed in the carpet, in the first case it will be a reinforced concrete well, and in the second - an electrified heat chamber.
Mounted carpet
The next element of the thermal network is a compensator. In the simplest case, this is laying of pipes in the form of the letter P or Z and any turn of the track. In more complex versions, lenzovy, gland and other compensating devices are used. The need to use these elements is caused by metals exposure to a significant temperature expansion. Simple words, pipe under action high temperatures Increases its length and so that it does not burst as a result of excessive load, they provide special devices or corners of the rotation of the track - they remove the voltage caused by the expansion of the metal.
P-shaped compensator
For the construction of subscriber networks, it is recommended to use as compensators only simple corners of the route. More complex devices, firstly, cost a lot, and secondly, require annual maintenance.
For the chartless gasket of pipelines, in addition to the corner itself, there is a small space for its operation. This is achieved by laying compensatory mats at the bend of the network. The absence of a soft plot will lead to the fact that at the time of expansion the pipe will be plugged in the ground and simply burst.
P-shaped compensator with laid mats
An important part of the thermal communication designer is also drainage. This device is a branch from the main pipeline with reinforcement, descending into a concrete well. If you need to empty the heat seafood, the cranes are open and the coolant is discarded. This element of the heating panel is installed in all lower points of the pipeline.
Drainage well
Removed water pumped out well special equipment. If there is an opportunity and appropriate permission is obtained, you can connect a reset well with household or storm sewer networks. In this case, special technique for operation will not be required.
On the small sites Networks, length up to several tens of meters, drainage is allowed not to be installed. When repairing, an extra coolant can be resetting the Dedovsky method - cutting the pipe. However, with such emptying, water should significantly reduce its temperature due to the danger of staff burns and the completion of the repair is slightly postponed.
Another design element, without which it is impossible to normal functioning of the pipeline is an airier. It is a branch of a thermal network, directed strictly upward, at the end of which the ball valve is located. This device is used to free the pipeline from the air. Without removal of gas plugs, it is impossible to normal filling the pipes with the coolant. This element is installed in all the upper points of the thermal network. It is impossible to abandon its use in any way - another method of removal of air from pipes has not yet come up.
Tees with a ball valve aircraft
When an air device follows functional ideas To be guided also by personnel security principles. When the air is descending there is a risk of burns. Distinguishing air tube must be directed toward or down.
Design
The work of the designer when creating a thermal network is not based on templates. Each time new calculations are conducted, equipment is selected. The reuse of the project is impossible. For these reasons, the cost of such work is always quite high. However, the price should not be the main criterion when choosing a designer. Not always the most expensive - the best, as well as the opposite. In some cases, the excessive cost is not caused by the labor intensity of the process, but the desire to fill the price. Experience in the development of such projects is also a considerable plus when selecting an organization. True, there are cases when the company has developed status and completely changed specialists: refused experienced and expensive in favor of young and ambitious. It would be nice to clarify this moment before the conclusion of the contract.
Designer choice rules
Cost. It must be in the middle range. The extremes are not appropriate.
Experience. To determine experience, the easiest way to ask customer phones, for which the organization has already performed similar projects and can not be lazy to call several numbers. If everything was "at the level", then you will receive the necessary recommendations if "not very" or "more or less" - you can safely continue the search further.
Availability in the staff of experienced employees.
Specialization. There should be avoided organizations that despite the small staff of the staff are ready to make a house with a pipe and a path to it. The lack of specialists leads to the fact that the same person can develop several sections at once, if not all. The quality of such works leaves much to be desired. Optimal option It will become a narrow-controlled organization with a bias in communication or energy construction. Large civil engineering institutions are also not the worst option.
Stability. One-day firms should be avoided, no matter how tempting their proposal. Well, if you can contact the institutes that are created on the basis of the old Soviet Research Institute. Usually they support the brand, and employees in these places often work all their lives and already "a dog" on such projects.
The design process begins long before the designer takes into the hands of a pencil (in modern version Before he sat in front of the computer). This work consists of several consecutive processes.
Stages of design
Collection of source data.
This part of the work can be entrusted with both the designer and the customer independently. It is not expensive, but it requires some time to visit the enon number of organizations, writing letters, statements and receiving answers. It should not be engaged in independently collecting source data for design only if you cannot explain what you specifically want to do.
Engineering survey.
The stage is rather complicated and cannot be performed independently. Some design organizations fulfill this work themselves, some are given to subcontract organizations. If the designer works on the second option, it makes sense to choose a subcontractor yourself. So the cost can be somewhat reduced.
The design itself is the design.
Performed by the designer, at any stage is controlled by the customer.
Project coordination.
Developed documentation must necessarily check the customer. After that, the designer coordinates it with third-party organizations. Sometimes to accelerate the process, it is enough to participate in this process. If the customer goes together with the developer in terms of approval, firstly not the opportunity to tighten the project, and secondly there is a chance to see all the shortcomings with their own eyes. If there are any controversial issues, the ability to control them also at the construction stage will appear.
Many organizations that produce the development of project documentation are offered alternative options Her species. Pictures the popularity of 3D design, color design drawings. All these decorating elements are purely commercial nature: add the cost of design and do not at all raise the quality of the project itself. Builders will work equally with any form of design and estimate documentation.
Drawing up a design contract
In addition to the already said, you need to add a few words about the constructing contract itself. From the items prescribed in it depends a lot. It is not always blindly accounted for a form proposed by the designer. Quite often, only the interest developer interests are taken into account.
The design contract must necessarily contain:
· full names of the parties
· Cost
· deadline
· subject contract
These items must be spelled out clearly. If the date is at least a month and year, and not through a certain number of days or months from the beginning of the design or from the beginning of the contract. An indication of this wording will put you in an awkward position if you suddenly have to prove something in court. Also, special attention should be paid to the name of the subject of the contract. It should not sound as a project and point, but as "execution design work on the heat supply of such a building "or" designing a thermal network from a certain place to a certain place. "
It is useful to register in the contract and some points of fines. For example, the delay in the design period entails payment by the designer 0.5% of the contract in favor of the Customer. It is useful to prescribe in the contract and number of project copies. The optimal amount is 5 pieces. 1 for yourself, 1 more for technical supervision and 3 for builders.
Full payment of work should be made only after 100% of the readiness and signing of the acceptance act (the act of work performed). When this document is issued, it is necessary to check the name of the project, it must be identically indicated in the contract. When recorded records, even one comma or letter, you risk not prove to pay for this agreement in the event of a controversial situation.
The next part of the article is devoted to the issues of construction. It will break the light at such moments as: Features of the selection of the contractor and the conclusion of the contract for execution construction workwill result in an example of the correct installation sequence and tell me how to do when the pipeline is already laid to avoid negative consequences during operation.
Olga Ustimkina, RMNT.ru
http: // www. RMNT. RU / - RMNT site. Ru
1. Basic conditions in the design of the thermal network:
Depending on the geological, climatological characteristics of the area, select the type of laying networks.
Fig. 6.
Methodology of hydraulic calculation of the thermal network.
Thermal network is deadlock.
Hydraulic calculation is made on the basis of nanograms for hydraulic calculation of the pipeline.
We consider the main highway.
Pipe diameters We select on the average hydraulic slope, taking specific pressure losses up to? P \u003d 80 per / m.
2) for additional sections G no more than 300 per / m.
Roughness pipe k \u003d 0.0005 m.
Record pipe diameters.
After the diameter of the heat network sections, we consider the amount of COEF for each site. Local resistances (? O), using a scheme of T.S., data on the location of the valves, compensators, and other resistance.
After that, for each site, we calculate the equivalent to the local resistance length (LEC).
Based on the losses of the subposition of feed and return lines and the necessary disposed of "at the end" of the highway, we determine the necessary disposable head on the output reservoirs of the heat source.
Table 7.1 - Definition of LEX. at? F \u003d 1 in DU.
Table 7.2 - calculation of equivalent lengths of local resistance.
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Local resistance |
Coeff Mest. Resisters (o) |
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Latch 1pc comp. Salne. 1 PC. Tee 1 piece |
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Printing 1 pc. Comp.Mal 1 PC. Tee 1pc. |
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Tee 1pc. Latch 1pc. |
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Latch 1pc. |
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Latch 1pc. Comp.P-shaped 1pc. |
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Latch 1pc. Comp.P-shaped 1pc. |
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Latch 1pc. Tee 1pc. |
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Latch 1pc. Tee 1pc. |
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Latch 1pc. Comp.P-shaped 1pc. |
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Latch 1pc. |
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Latch 1pc. Tee 1pc. |
Every 100m. Installed a compensator of thermal elongation.
For diameter of pipelines up to 200 mm. We accept P-shaped compensators, over 200 - salon, bellows.
Losses DPZ pressure are on the nanogram, P / m.
Pressure loss is determined by the formula:
DP \u003d DPZ *? L * 10-3, kPa.
V (m3) of the site is determined by the formula:
Calculation of water consumption of the pipeline, M (kg / s).
mOT + veins \u003d \u003d \u003d 35.4 kg / s.
mG.V. \u003d \u003d \u003d 6.3 kg / s.
mit \u003d MOT + veins + MG.V. \u003d 41.7 kg / s
Calculation of water consumption by plots.
QKV \u003d z * FKV
z \u003d QUCH /? FKV \u003d 13320/19 \u003d 701
QKV1 \u003d 701 * 3,28 \u003d 2299.3 kW
QKV2 \u003d 701 * 2.46 \u003d 1724.5 kW
QKV3 \u003d 701 * 1,84 \u003d 1289.84 kW
QKV4 \u003d 701 * 1.64 \u003d 1149.64 kW
QKV5 \u003d 701 * 1,23 \u003d 862.23 kW
Qv6 \u003d 701 * 0.9 \u003d 630.9 kW
QKV7 \u003d 701 * 1.64 \u003d 1149.64 kW
QKV8 \u003d 701 * 1,23 \u003d 862.23 kW
QKV9 \u003d 701 * 0.9 \u003d 630.9 kW
QKV10 \u003d 701 * 0,95 \u003d 665.95 kW
QKV11 \u003d 701 * 0.35 \u003d 245.35 kW
QKV12 \u003d 701 * 0.82 \u003d 574.82 kW
QKV13 \u003d 701 * 0.83 \u003d 581,83kW
QKV14 \u003d 701 * 0.93 \u003d 651,93kW
Table 7.3 - water consumption for each quarter.
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m1 \u003d \u003d 6.85kg / s |
m8 \u003d \u003d 2.57 kg / s |
|
m2 \u003d \u003d 5.14 kg / s |
m9 \u003d \u003d 1.88kg / s |
|
m3 \u003d \u003d 3.84kg / s |
m10 \u003d \u003d 1.98 kg / s |
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m4 \u003d \u003d 3.42kg / s |
m11 \u003d \u003d 0.73 kg / s |
|
m5 \u003d \u003d 2.57 kg / s |
m12 \u003d \u003d 1.71kg / s |
|
m6 \u003d \u003d 1.88kg / s |
m13 \u003d \u003d 1.73 kg / s |
|
m7 \u003d 3.42kg / s |
m14 \u003d \u003d 1.94 kg / s |
Water consumption for each site is equal to (kg / s):
mg4-g5 \u003d M10 + 0.5 * M7 \u003d 1.98 + 0.5 * 3.42 \u003d 3.69
mg3-g4 \u003d M11 + Mg4-g5 \u003d 3.69 + 0.73 \u003d 4.42
mg2-g3 \u003d M12 + Mg3-g4 \u003d 4.42 + 1.71 \u003d 6.13
mg1-r2 \u003d 0.5 * M3 + 0.5 * M8 + Mg2-g3 \u003d 0.5 * 3.42 + 0.5 * 2.57 + 6,13 \u003d 9.12
m2-G1 \u003d M4 + 0.5 * M5 + Mg1-r2 \u003d 9.12 + 3.42 + 0.5 * 2.57 \u003d 13.8
m2-B1 \u003d M1 + 0.5 * M2 \u003d 9.42
m1-2 \u003d M2-G1 + M2-B1 \u003d 13.8 + 9,42 \u003d 23,22
mA2-A3 \u003d M13 + M14 \u003d 3.67
mA1-A2 \u003d 0.5 * M8 + M9 + MA2-A3 \u003d 0.5 * 2.57 + 1.88 + 3,67 \u003d 6.83
m1-A1 \u003d 0.5 * M5 + M6 + MA1-A2 \u003d 9.99
m1-B1 \u003d 0.5 * M2 + M3 \u003d 6,41
mA-1 \u003d M1-B1 + M1-A1 + M1-2 \u003d 6,41 + 9.99 + 23,22 \u003d 39.6
Record the data obtained in Table 8.
Table 8 - hydraulic calculation of the thermal network of the region. 7.1 Selection of network and feed pumps.
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Dimensions of pipes |
Length of the site |
Pressure loss DP |
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plot, m3. |
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Main highway |
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Branch from highway |
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Table 9 - to build piezometric graph.
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Pipe size |
Length of the site |
Pressure loss Dr. |
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Main highway |
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HMEST \u003d 0.75mHD \u003d 30 m
Looking \u003d 4mhPactive \u003d? H \u003d (Hatshest + HTP + Hollow) \u003d 34.75 m
V \u003d 16.14 m3 / C- for selecting a feed pump
hatching \u003d 3.78 mHTSU \u003d 15 m
wrinkle \u003d 3.78 mhrasnap \u003d 4 m
hset \u003d 26.56 m; m \u003d 142.56 m3 / h -d selection of a network pump
For a closed heat supply system working with an increased control graph with a total heat flux Q \u003d 13.32 MW and with the calculated flow of the coolant G \u003d 39.6 kg / s \u003d 142.56 m3 / h, choose network and feed pumps.
Required Network Pump Pump H \u003d 26.56 m
According to a methodological manual, we accept the installation of one Network Pump COP 125-55 providing the required parameters.
The required pressure of the sample pump HPN \u003d 16.14 m3 / h. Required pressure of the feed pump H \u003d 34.75 m
PUBLIC PUMP: 2K-20/20.
According to the methodological manual, we accept the two successively connected feed pumps 2k 20-20 providing the required parameters.
Fig. eight.
Table 10 - technical characteristics of pumps.
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Name |
Dimension |
Mapported |
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The reference manual covering the design of thermal networks is the "Designer's Handbook. Design of thermal networks. " The directory can be subject to a certain extent to be considered as a manual for SNIP II-7.10-62, but not to SNIP N-36-73, which has emerged significantly later as a result of the essential processing of the previous edition of the norms. Over the past 10 years, the SNIP N-36-73 text has been subjected to significant changes and additions.
Thermal insulation materials, products and structures, as well as the methods of their thermal calculations, together with the instructions for the implementation and acceptance of insulation work, are described in detail in the "Builder's Guide". Similar data on thermal insulation structures included in CH 542-81.
Reference materials on hydraulic calculations, as well as equipment and automatic regulators for thermal networks, thermal points and heat use systems are contained in the "Handbook on the commissioning and operation of water heat networks". As a source of reference materials on design issues, books from a series of reference books "Heat and power engineering and heat engineering" can be used. The first book "General questions" provides the rules for the design of drawings and schemes, as well as data on the thermodynamic properties of water and water vapor, more detailed data is given in. In the second book of the series "Heat and mass exchange. The heat engineering experiment "includes data on the thermal conductivity and viscosity of water and water vapor, as well as by density, thermal conductivity and heat capacity of some construction and insulating materials. In the fourth book "Industrial power engineering of heat engineering" there is a section dedicated to the heat and thermal networks
www.engineerclub.ru.
The book provides regulatory materials used in the design of thermal networks and thermal points. Recommendations on the choice of equipment and heat supply schemes are considered calculations related to the design of heat networks. Information on the laying of thermal networks is given on the organization of construction and operation of heat networks and thermal points. The book is designed for engineering and technical workers engaged in the design of thermal networks.
Housing and industrial construction, fuel economy requirements and environmental protection predetermine the feasibility of intensive development of centralized heat systems. The generation of thermal energy for such systems is currently produced by thermal electrofentrals, the boilers of the district value.
The reliable operation of heat supply systems with strict observance of the necessary parameters of the coolant is largely determined right choices Systems of thermal networks and thermal items, installation designs used equipment.
Considering that the correct design of thermal networks is impossible without knowledge of their device, work and development trends, the authors tried to lead the recommendations on the design and give a brief justification.
The overall characteristics of thermal networks and thermal points
1.1. Central Heating Systems and their Structure
Centralized heat supply systems are characterized by a combination of three main links: heat sources, thermal networks and local heat use systems (heat consumption) of individual buildings or structures. In the heat sources, heat is obtained by burning different species Organic fuel. Such heat sources are called boiler rooms. In the case of use in heat sources of heat released during the decay of radioactive elements, they are called heat supply atomic stations (ACT). In some heat supply systems, heat-resumed heat sources are used as auxiliary energy, geothermal energy, solar radiation energy, etc.
If the heat source is located together with heat carriers in one building, the pipelines for supplying the coolant to heat transiters passing inside the building are considered as an element of a local heat supply system. In systems of centralized heat supply, heat sources are located separately standing buildings, And the vehicles of heat from them are carried out on pipelines of heat networks, to which the heat use systems of individual buildings are attached.
The scale of centralized heat supply systems may vary widely: from small serving several neighboring buildings to the largest, covering a number of residential or industrial areas and even the city as a whole.
Regardless of the scale, these systems at the contingent of served consumers are divided into utilities, industrial and citywide. Communal includes systems that provide heat mainly residential and public buildings, as well as individual buildings of industrial and utility warehouse, the placement of which in the residential zone of cities is allowed.
The classification of utility systems on their scale is to be appropriately put in the norms of planning and development of cities. Membership of the territory of the area of \u200b\u200bthe zone into groups of neighboring buildings (or quarters in the areas of the old building), united in microdistrics with a population of 4 - 6 thousand people. In small cities (with a population of up to 50 thousand people) and 12-20 thousand people. In the cities of the rest of the categories. The latter provides for the formation of several population neighborhoods with a population of 25 - 80 thousand people. The corresponding centralized heat supply systems can be described as group (quarterly), microdistrict and district.
The heat sources serving these systems, one per each system, can be attributed according to the category of group (quarterly), microdistrict and district boiler rooms. In large and largest cities (with population, respectively, 250-500 thousand people and more than 500 thousand people.) The norms provide for the combination of several adjacent residential areas in planning areas, limited by natural or artificial overgrowths. In such cities there may be the appearance of the largest inter-district systems of municipal heat supply.
At a large scale of heat generation, especially in citywide systems, it is advisable to joint heat and electricity generation. This provides significant fuel savings compared to separate production of heat in boiler rooms, and electricity - on thermal power plants due to burning the same types of fuel.
Thermal power plants intended for joint generation of heat and electricity are called thermal power plants (CHP).
Atomic power plants using heat released during the decay of radioactive elements to generate electricity, it is also sometimes advisable to use both heat sources in large heat supply systems. These stations are called atomic thermal power plants (APEC).
Systems of centralized heat supply using CHPs as the main heat sources are called wellness. The issues of the construction of new centralized heat supply systems, as well as the expansion and reconstruction of existing systems require special stake, based on the prospects for the development of the relevant settlements for the nearest period A0-15) and the estimated period of 25-30 years).
The norms provide for the development of a special pre-project document, namely the heat supply schemes of this settlement. There are several options in the diagram. technical solutions On heat supply systems and on the basis of technical and economic comparison, the choice of the option proposed to approval is justified.
The subsequent development of projects of heat sources and thermal networks should be carried out only on the basis of decisions adopted in the approved heat supply scheme of this settlement.
1.2. general characteristics Heat networks
Thermal networks can be classified by the type of coolant used in them, as well as according to its calculated parameters (pressures and temperatures). Almost only heat carriers in thermal networks are hot water and water vapor. Water steam as a coolant is used everywhere in the heat sources (boiler rooms, CHP), and in many cases - in the systems of heat used, especially industrial. Communal heat supply systems are equipped with water thermal networks, and industrial or vapor, or steam in combination with water, used to cover the loads of heating, ventilation and hot water supply. Such a combination of water and steam thermal networks is also characteristic of citywide heat supply systems.
Water thermal networks for the most part They are performed by two-pipe with a combination of feed pipelines for supplying hot water from heat sources to heat use systems and return pipes for returning water cooled in these systems to heat sources for reheating. The supply and inverse pipelines of water thermal networks together with the corresponding pipelines of heat sources and heat use systems form closed circuits of water circulation. This circulation is maintained by network pumps installed in heat sources, and with large parts of the transport of water - also on the track of networks ( pumping stations). Depending on the adopted connection scheme, hot water systems are distinguished closed and open schemes (The terms "closed and open heat supply systems") are more often used).
In closed systems, the release of heat from networks in the hot water system is carried out by heating, cold tap water in special water heaters.
In open systems, the hot water load coating is carried out due to the supply of water consumers from supply pipelines of networks, and during the heating period - in a mixture with water from the return pipelines of heating and ventilation systems. If, with all modes for hot water supply, completely water from inverse pipelines can be used, then the need for the return pipelines from thermal points to the heat source. Compliance with these conditions, as a rule, perhaps only with the collaboration of several heat sources into common heat networks with the laying of hot water loads on some of these sources.
Water networks consisting only of supply pipelines are called single-tube and over capital investments in their construction are the most economical. Suggesting thermal networks in closed and open systems is carried out due to the work of the feed pumps and installations for the preparation of feed water. IN open system Their required performance is 10-30 times greater than in closed. As a result, with a large-owned system, capital investments in the heat sources are large. At the same time, in this case, the need disappears in the heaters of tap water, and therefore the costs of attaching hot water systems to thermal networks are significantly reduced. Thus, the choice between open and closed systems In each case, should be justified by technical and economic calculations, taking into account all the links of the centralized heat supply system. Such calculations should be performed in the development of the heat supply scheme of the settlement, i.e., before the design of the corresponding heat sources and their thermal networks.
In some cases, water thermal networks are performed by three- and even four-pipe. Such an increase in the number of pipes, usually envisaged only in some sections of networks, is associated with doubling or only feed (three-pipe systems), or both feed and reverse (four-pipe systems) of pipelines for separate attachment to the corresponding pipelines of hot water systems or heating and ventilation systems . Such a division greatly facilitates the regulation of heat release into the system various destinationBut at the same time leads to a significant increase in capital investments on the network.
In large systems of centralized heat supply, there is a need for the separation of water heat networks into several categories, each of which can use their own heat and heat transport schemes.
The norms provide for the division of thermal networks into three categories: the mains from the heat sources to the inputs to the neighborhoods (quarters) or enterprises; Distribution of trunk networks to networks to individual buildings: networks to individual buildings in the form of branches from distribution (or in some cases from trunk) networks to nodes of accession systems to them heat use of individual buildings. These names must be clarified in relation to adopted in § 1.1 classification of centralized heat supply systems on their scale and contingent of consumer services. So, if in small systems from one heat source, heat is carried out only to the group of residential and public buildings within the neighborhood or production buildings One enterprise, the need for trunk thermal networks disappears all networks from such heat sources should be considered as distributive. This provision is typical for use as heat sources of group (quarterly) and microdistrict boiler houses, as well as industrial serving one enterprise. When moving from such small systems to the district, and even more so the interdistrict a category of main thermal networks appears, to which the distribution networks of individual neighborhoods or enterprises of one industrial area are joined. The addition of individual buildings directly to the main networks, in addition to the distribution, for a number of reasons is extremely undesirable, and therefore it is very rare.
Major heat sources of district and inter-district systems of centralized heat supply should be placed outside the residential zone in order to reduce the effects of their emissions on the state of the air basin of this zone, as well as simplifying liquid or solid fuel supply systems.
In such cases, the initial (head) sections of the main networks of considerable length appear, within which there are no junction nodes of the distribution networks. Such a transport of the coolant without a passing distribution of its consumers is called transit, while the corresponding head sections of the main heat networks are advisable to highlight into a special category of transit.
The presence of transit networks significantly worsens the technical and economic indicators of the transport of the coolant, especially with the length of these networks in 5 - 10 km and more, which is characteristic, in particular, when used as the heat sources of atomic CHP or heat supply stations.
1.3. General characteristics of thermal points
An essential element of centralized heat supply systems are installations placed in nodes of accession to thermal networks of local heat use systems, as well as at the junctions of networks of various categories. In such installations, the operation of heat networks and thermal use systems and the management of them are carried out. Here is the measurement of the parameters of the coolant - pressures, temperatures, and sometimes expenses - and regulation of heat leave at various levels.
From the work of such installations depend largely reliability and economy of heat supply systems as a whole. These installations in regulatory documents are called thermal points (also the names of the "Joining of local tple use systems", "Heat centers", "Subscriber installations", etc. were also applied, and so paragraphs).
However, the classification of thermal points adopted in the same documents is advisable to clarify somewhat, since they are all heat points either to central (CTP), or to individual (ITP). The latter includes only installations with hubs of accession to thermal networks of thermal use of one building or their parts (in large buildings). All other thermal points regardless of the number of serviced buildings refer to the central.
In accordance with the accepted classification of thermal networks, as well as various heat recovery steps, the following terminology is used. In terms of thermal points:
local heat points (MTP), serving systems for thermal use of individual buildings;
group or microdistrict thermal items (GTR) serving a group of residential buildings or all buildings within the microdistrict;
district thermal points (RTP) serving all buildings within residential
In terms of regulatory steps:
central - only on heat sources;
district, group or microdistrict - on the corresponding thermal points (RTP or GTP);
local - in local thermal points of individual buildings (MTP);
individual on individual heat carriers (devices of heating systems, ventilation or hot water supply).
Home Mathematics, Chemistry, Physics Designing the heat supply system of the hospital complex
27. Safonov A.P. Collection of tasks for heat and thermal networks Tutorial for universities, M.: Energoatomizdat. 1985.
28. Ivanov V.D., Gladysh N.N., Petrov A.V., Kazakova T.O. Engineering calculations and methods of testing thermal networks Abstract lectures. St. Petersburg: St. Petersburg GSU RP. 1998.
29. Instructions for the operation of thermal networks M.: Energy 1972.
30. Safety regulations for servicing thermal networks M: Atomizdat. 1975.
31. Yurev V.N. Heat engineering handbook in 2 volumes m.; Energy 1975, 1976.
32. Golubkov B.N. Heat engineering equipment and heat supply industrial enterprises. M.: Energy 1979.
33. Shubin E.P. The main issues of designing heat supply systems. M.: Energy. 1979.
34. Methodical instructions on the preparation of the report of the power plant and the joint-stock company of the energy and electrification on the thermal economy of the equipment. RD 34,41552-95. CPO ORGRES M: 1995.
35. Definition technique specific expenses Fuel to heat depending on the parameters of the steam used for the heads of heat supply RD 34.09.159-96. CPO OrGRs. M.: 1997.
36. Methodical instructions on the analysis of the change in the specific costs of fuel in the energy stations and in power facilities. RD 34.08.559-96 SPO OrGRES. M.: 1997.
37. Kutta G. P., Makarov A. A., Shamraev N.G. Creating a favorable base for the development of Russian electric power engineering on a market basis "Thermal Engineering". №11, 1997. C.2-7.
38. Bushuev V.V., Gromov B.N., Dobrochotov V.N., Prikyin V.V., Scientific and Technical and Organizational Problems of Energy Saving Technologies. "Heat and power engineering". №11. 1997. P.8-15.
39. Astakhov H.L, Kalimov V.F., Kiselev G.P. The new edition of the methodological instructions on the calculation of indicators of the thermal economy of the TPP equipment. "Energy saving and water treatment." № 2, 1997, from 19-23.
Ekaterina igorevna Tarasevich
Russia
Chief Editor -
candidate of Biological Sciences
The article discusses the change in a number of published regulatory documents for thermal insulation of heat supply systems, which are aimed at ensuring the durability of the system. This article is devoted to the study of the impact of the average annual temperature of thermal networks on thermal loss. The study relates to heat supply systems and thermodynamics. Recommendations are given on the calculation of the normative heat loss through the insulation of pipelines of thermal networks.
The relevance of the work is determined by the fact that it appeals to low-investigated problems in the heat supply system. The quality of thermal insulation structures depends on the thermal loss of the system. Proper design And the calculation of the thermal insulation design is much more important than just choosing an insulating material. Results are given comparative analysis heat losses.
The methods of thermal calculations of the calculation of heat lines of thermal networks are based on the use of the regulatory density of the heat flux through the surface of the heat insulating structure. In this article, the example of pipelines with polyurethane foam insulation was calculated by thermal losses.
Basically, the following conclusion was made: in existing regulatory documents, the total values \u200b\u200bof the density of thermal flows for the feed and return pipelines are presented. There are cases where the diameters of the feed and return pipelines are not the same, in one channel can be laid both both three and more pipelines, therefore, it is necessary to use the previous standard. The total values \u200b\u200bof the density of thermal flows in the norms can be divided between the feed and return pipelines in the same proportions as in the replaced standards.
Snip 41-03-2003. Thermal insulation of equipment and pipelines. Actualized edition. - M: Ministry of Regional Development of Russia, 2011. - 56 p.
Snip 41-03-2003. Thermal insulation of equipment and pipelines. - M.: Gosstroy Russia, FSUE CPP, 2004. - 29 p.
SP 41-103-2000. Design of thermal insulation of equipment and pipelines. M: Gosstroy Russia, FSUE CPP, 2001. 47 p.
GOST 30732-2006. Steel pipes and shaped products with thermal insulation of polyurethane foam with a protective shell. - M.: Starotinform, 2007, 48 p.
The design standards for thermal insulation for pipelines and equipment of power plants and thermal networks. M.: Gosstroyisdat, 1959. - URL: http://www.politerm.com.ru/zuluthermo/help/app_thermoleaks_year1959.htm
SNiP 2.04.14-88. Thermal insulation of equipment and pipelines / Gosstroy USSR.- M.: CITP GOSTORS OF THE USSR, 1998. 32 p.
Belyykina I.V., Vitalev V.P., Gromov N.K. and etc.; Ed. Gromova NK.; Shubina E.P. Water thermal networks: Design reference manual. M.: Energoatomizdat, 1988. - 376 p.
Ionin A.A., Chibs B. M., Bandenkov V. H., Terletskaya E. H.; Ed. A.A. Ionina. Heat supply: Textbook for universities. M.: Stroyzdat, 1982. 336 p.
Lienhard, John H., A Heat Transfer Textbook / John H. Lienhard IV and John H. Lienhard V, 3rd ED. Cambridge, MA: Phlogiston Press, 2003
Silverstein, C.C., "Design and Technology of Heat Pipes for Cooling and Heatexchange," Taylor & Francis, Washington DC, USA, 1992
European Standard EN 253 District Heating Pipes - Preinsulated Bonded Pipe Systems for Directly Buried Hot Water Networks - Pipe Assembly of Steel Service Pipe, Polyurethane Thermal Insulation and Outer Casing Of Polyethylene.
EUROPEAN STANDARD EN 448 DISTRICT HEATING PIPES. Preinsulated Bonded Pipe Systems for Directly Buried Hot Water Networks. Fitting Assemblies of Steel Service Pipes, Polyurethane Thermal Insulation and Outer Casing Of Polyethylene
DIN EN 15632-1: 2009 District Heating Pipes - Pre-Insulated Flexible Pipe Systems - Part 1: Classification, General Requirements and Test Methods
Sokolov E.Ya. Heat and thermal network tutorial for universities. M.: Publishing House MEI, 2001. 472 p.
Snip 41-02-2003. Heating network. Actualized edition. - M: Ministry of Regional Development of Russia, 2012. - 78 p.
Snip 41-02-2003. Heating network. - M: Gosstroy Russia, 2004. - 41 p.
Nikolaev A.A. Projecting thermal networks (director of the designer) / A.A. Nikolaev [and others]; Ed. A.A. Nikolaeva. - M.: Science, 1965. - 361 p.
Varfolomeev Yu.M., Kokorin O.Ya. Heating and thermal networks: tutorial. M.: Infra-M, 2006. - 480 c.
Kozin V. E., Levina T. A. Markov A. P., Pronon I. B., Slemzin V. A. Heat supply: Tutorial for students of universities. - M.: Higher. School, 1980. - 408 c.
Safonov A. P. Collection of tasks for heat and thermal networks: studies. Handbook for universities. 3rd ed., Pererab. M.: Energoatomizdat, 1985. 232 p.
Publication date: 06.02.2017 2017-02-06
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Ushakov D.V., Snisar D. A., Kitaev D. N. Definition of coefficients local losses In thermal networks of industrial enterprises // Young scientist. - 2017. - №6. - P. 95-98. - URL https://moluch.ru/archive/140/39326/ (Reference date: 07/13/2018).
The article presents the results of the analysis of the actual values \u200b\u200bof the coefficient of local losses used in the design of thermal networks at the pre-hydraulic calculation stage. Based on the analysis of actual projects, averaged values \u200b\u200bare obtained for industrial disclosure networks with division on highways and branch. Equations are found to calculate the coefficient of local losses depending on the diameter of the network pipeline.
Keywords : thermal networks, hydraulic calculation, local loss coefficient
In the hydraulic calculation of thermal networks there is a need for a task of the coefficient α which takes into account the share of pressure loss in local resistances. In modern standards, the execution of which is mandatory in design, about the normative method of hydraulic calculation and specifically the coefficient α does not say. In modern reference and educational literature, they are usually given the values \u200b\u200brecommended by the canceled SNiP II-36-73 *. In tab. 1 shows values α For water networks.
Coefficient α to determine the total equivalent lengths of local resistances
Type of compensators
Conditional Pipeline Pass, mm
Branched thermal networks
P-shaped with bent discharges
P-shaped with welded or cool discharge
P-shaped with welded discharges
From Table 1 it follows that the value α It may be in the range from 0.2 to 1. An increase in value with an increase in the diameter of the pipeline is traced.
In the literature for preliminary calculations, when the diameters of the pipes are not known, the stake of pressure loss in local resistances is recommended to determine by the formula B. L. Sifreson
where z. - coefficient taken for water networks 0.01; G. - water consumption, t / h.
The results of calculations according to formula (1) at various water flows in the network are presented in Fig. one.
Fig. 1. Dependence α From water consumption
From fig. 1 it follows that value α At large expenditures, there may be more than 1, and at small less than 0.1. For example, at a flow rate of 50 t / h, α \u003d 0.071.
The literature shows an expression for the local loss coefficient
where - the equivalent length of the section and its length, respectively, m; - the sum of the coefficients of local resistances on the site; λ - coefficient of hydraulic friction.
When designing water heat networks during turbulent motion mode for finding λ Use the Schiffinson formula. Taking the value of equivalent roughness k E.\u003d 0.0005 mm, formula (2) is converted to mind
.(3)
From formula (3) it follows that α Depends on the length of the site, its diameter and the sum of the coefficients of local resistances, which are determined by the network configuration. Obviously, meaning α Increases with a decrease in the length of the site and increasing the diameter.
In order to determine the actual coefficients of local losses α The existing projects of water thermal networks of industrial enterprises of various purposes were considered. Positioning the hydraulic calculation forms, the coefficient was determined for each site. α By formula (2). Separately on the highway and branches were the weighted average values \u200b\u200bof the local loss coefficient for each network. In fig. 2 presents the results of calculations α According to the calculated highways for sampling from 10 network schemes, and in Fig. 3 for branches.
Fig. 2. Actual values α on settlement highways
From fig. 2 it follows that minimum value 0.113, the maximum 0.292, and the average value in all schemes is 0.19.
Fig. 3. Actual values α in branches
From fig. 3 It follows that the minimum value of 0.118, the maximum 0.377, and the average value in all schemes is 0.231.
Comparing the obtained data with recommended, the following conclusions can be made. According to the table. 1 for the considered schemes α 0.3 for highways and α \u003d 0.3 ÷ 0.4 for branches, and the average actual is 0.19 and 0.231, which is somewhat less recommended. Range of actual values α Does not exceed the recommended, i.e. table values \u200b\u200b(Table 1) can be interpreted as "not more".
Mid-average values \u200b\u200bwere defined for each diameter of the pipeline α on highways and branches. The calculation results are presented in Table. 2.
The values \u200b\u200bof the actual coefficients of local losses α
From the analysis of Table 2 it follows that with an increase in the diameter of the pipeline value of the coefficient α Increases. The method of the least squares was obtained linear regression equations for the highway and branches depending on the outer diameter:
In fig. 4 presents the results of calculations using equations (4), (5), and actual values \u200b\u200bfor the corresponding diameters.
Fig. 4. Results of calculations of coefficients α According to equations (4), (5)
Based on the analysis of real projects of thermal water networks of industrial plants, the averaged values \u200b\u200bof local losses with division on highways and branch were obtained. It is shown that the actual values \u200b\u200bdo not exceed the recommended, and the average, slightly less. Equations obtained that allow you to calculate the coefficient of local losses depending on the diameter of the network pipeline for highways and branches.
Energy is the main product that has learned to create a person. It is necessary for both household exercises and industrial enterprises. In this article we will talk about the norms and rules for the design and construction of outdoor thermal networks.
This is a combination of pipelines and devices that are engaged in reproduction, transportation, storage, regulation and provision of all means of nutrition with heat by hot water or steam. It falls from the energy source in the transmission line, and then distributed through the room.
What is included in the design:
Also, the heat supply project may contain optional equipment Inside the engineering system of heating and supplying hot water. So the design is divided into two parts - the outer and inner heating network. The first can go from the central main pipelines, and maybe from the thermal node, boiler room. Indoors also have systems that regulate the amounts of heat in individual rooms, workshops - if the question concerns industrial enterprises.
There are several criteria for which the system may vary. This is the way they are accommodated, and the appointment, and the heat supply area, their power, as well as many additional functions. The designer at the time of the design of the heat supply system will definitely learn from the customer how much energy should transport a line everybody, how many outlet holes to have, what operating conditions will be climatic, meteorological, as well as how not to ruin urban development.
According to this data, you can choose one of the types of laying. Consider classifications.
Distinguish:
This solution is applied too often due to installation difficulties, service, repair, as well as due to an unsightly type of such bridges. Unfortunately, the project usually does not include decorative elements. This is due to the fact that the cobes and other disguise designs often prevent access to the pipes, and also interfere with the timely to see the problem, for example, a curse or crack.
The solution to the design of air heating networks is taken after engineering surveys for examination of areas with seismic activity, as well as high level of occurrence groundwater. In such cases, there is no possibility to dig trenches and carry out ground laying, as it can be unproductive - natural conditions They may damage the skin, humidity will affect accelerated corrosion, and the mobility of the soil will lead to the breakfasts of the pipe.
Another recommendation for overhead structures is a dense residential building, when it is simply no possibility to dig a holes, or in the case when there is one or more lines of existing communications in this place. When carrying out land work in this case, the risk of damage engineering systems cities.
Air heat seafood on metal supports and pillars, where they are attached to hoops.
They, respectively, are laid underground or on it. There are two variants of the heat supply system project - when the laying is carried out in a channel and chamberless.
In the first case, a concrete channel or tunnel is paved. Concrete reinforced, pre-prepared rings can be used. It protects pipes, winding, and also facilitates the process of checking and maintenance, since the entire system is clean and dry. Protection occurs simultaneously from moisture, groundwater and sublopulations, as well as from corrosion. Including such precautions help prevent mechanical effect on line. Channels can be monolithic filling with concrete or prefabs, their second name is tray.
The infantless method is less preferable, but it takes much less time, labor and material resources. It is economically effective methodBut the pipes themselves are not usually used, and special - in a protective sheath or without it, but then the material should be from polyvinyl chloride or with its addition. The repair and installation process makes it difficult if the network reconstruction is assumed, the expansion of the heating system, as it is necessary to perform land work again.
Two elements can be transported:
It transmits thermal energy and can continue to serve for water purposes. The peculiarity is that such pipelines do not fit alone, even the main. They must be carried out in quantity, multiple two. Usually it is two-pipe and four-pipe systems. This requirement is due to the fact that not only the supply of fluid is needed, but also its discovery. Usually the cold stream (reverse) is returned to the heat point. In the boiler room, secondary processing occurs - filtering, and then water heating.
These are more difficult in the design of the heating network - an example of their typical project contains the conditions for protecting pipes from supergious temperatures. The fact is that the steam carrier is much hotter than the liquid. This gives an increased efficiency, but contributes to the deformation of the pipeline, its walls. This can be prevented if you use high-quality building materials, as well as regularly monitor possible changes in pressure presses.
It is also dangerous another phenomenon - the formation of condensate on the walls. It is necessary to make a winding that will divert moisture.
The danger also lies in connection with possible injuries when servicing and a breakthrough. A steam burn is very strong, and since the substance is transmitted under pressure, it can lead to significant damage to the skin.
Also, this classification can be called - by value. Distinguish the following objects:
They have one only function - transportation for long distances. This is usually the transmission of energy from the source, boiler room, to distribution units. Here there may be heat-albums that are engaged in the ramition of the tracks. The highways have powerful indicators - the temperature of the contents up to 150 degrees, the diameter of the pipes - up to 102 cm.
This is less significant lines whose goal is to deliver hot water or couples to residential buildings and industrial enterprises. By section, they can be different, it is chosen depending on the passability of energy per day. For apartment houses And the plants usually use maximum values \u200b\u200b- they do not exceed 52.5 cm in diameter. While for private ownership, residents usually supply a small pipeline that can quench their needs warm. Temperature mode Usually does not exceed 110 degrees.
This is a distribution subtype. They possess the same technical characteristicsBut serve the purpose of the distribution of the substance along the buildings of one residential building, the quarter.
They are designed to connect the highway and heat plug.
Distinguish:
The initial point of heat transfer is a major heating station that feeds the entire city or a large part of it. It can be CHP, large boiler houses, nuclear power plants.
They are engaged in transportation from small sources - autonomous heat-mounted, which can only supply a small residential building, one apartment building, specific industrial production. Autonomous power sources, as a rule, do not need plots of highways, as they are near the object, building.
The customer provides the technical task of the designer and independently or through third-party organizations is a list of information that will be needed in the work. This is the amount of heat that is required per year and daily, designation of power points, as well as operating conditions. Here may be preferences at the maximum value of all works and materials used. The first thing in the order must be indicated, for which it is necessary to the heating network - residential premises, production.
Works are carried out both on the ground and in laboratories. Then the engineer fills reports. The inspection system includes soil, soil properties, groundwater level, and climatic and meteorological conditions, seismic characteristics of the area. To work and design reporting, you will need a bunch of ++. These programs will provide automation of the entire process, as well as compliance with all rules and standards.
At this stage, drawings are drawn up, schemes of individual nodes, calculations are performed. This designer always uses high-quality software, for example. Software is designed to work with engineering networks. With it, it is convenient to carry trace, create wells, indicate the intersection of lines, as well as note the cross section of the pipeline and make additional marks.
Regulatory documents guided by the designer - SNiP 41-02-2003 "Heat networks" and SNiP 41-03-2003 "Thermal insulation of equipment and instruments".
At the same stage, construction and project documentation is issued. To comply with all GOST, SP and SNiP rules, you need to use the program or. They automate the process of filling the paper on legislation standards.
First, the layout is offered to the customer. At this point, it is convenient to use the 3D visualization feature. The volumetric model of the pipeline is visualine, it shows all the nodes that are not noticeable in the drawing man who are not familiar with the rules of drawing. And for professionals, a three-dimensional layout is necessary to make adjustments to provide unwanted intersections. Such a function has the program. It is convenient to make all the working and project documentation, draw and produce basic calculations using a built-in calculator.
Then the coordination must pass in a number of instances of the city administration, as well as to undergo an expert assessment by an independent representative. It is convenient to use the feature of electronic document management. This is especially true when the customer and the performer are in different cities. All products of Zvsoft cooperate with common engineering, textual and graphic formats, so the designers command can use this data processing software received from different sources.
The main elements of the pipeline are mainly produced by manufacturers in the finished form, so it remains only to position and mounted them.
Consider the content of the details on the example of the classical system:
Make the heating network project qualitatively along with software products from ZvSoft.
Competent and qualitative is one of the main conditions for the rapid object of operation.
Heating network Designed to transport heat from heat sources to the consumer. Thermal networks relate to linear structures and are one of the most complex engineering networks. The design of networks must include calculation on strength and temperature deformations. We expect each element of the thermal network for at least 25 years (or another at the request of the customer), taking into account the specific temperature history, thermal deformations and the number of launches of the network operation stops. An integral part of the design of the heat network should be the architectural and construction part (AC) and reinforced concrete or metal structures (CZH, KM), which develops fasteners, channels, supports, or overpass (depending on the gasket method).
1. By the nature of the transported coolant:
2. According to the method of laying thermal networks:
3. With regard to diagrams, heat networks can be:
NTC Energoservis Performs comprehensive software works, including urban highways, internal distribution and domestic networks. The design of networks of the linear portion of thermal chains is performed using both typical and individual nodes.
The qualitative calculation of thermal networks allows you to compensate for thermal extensions of pipelines due to the corners of the turns of the track and check the correctness of the planned-high position of the track, the installation of bellows compensators and fixing fixed supports.
Thermal lengthening of heat lifting with a non-channel gasket is compensated due to the corners of the turns of the highway, which form self-adensive sections of P, r, z-shaped, installation of starting compensators, fixing fixed supports. At the same time, on the corners of turns, there are special pillows from foamed polyethylene (mats) between the wall of the trench and the pipeline, which provide free movement of pipes with their temperature elongations.
All documentation in design of thermal networks Developed in accordance with the following regulatory documents:
Snip 207-01-89 * "Urban planning. Planning and building cities, villages and rural settlements. Network design standards ";
- Snip 41-02-2003 "Heat networks";
- SNIP 41-02-2003 "Thermal insulation of equipment and pipelines";
- SNiP 3.05.03-85 "Heat networks" (enterprise of thermal networks);
- GOST 21-605-82 "Thermal networks (heatherecanic part)";
- rules for the preparation and production of earthworks, devices and content of construction sites in the city of Moscow, approved by the Government Decree No. 857-PP dated December 7, 2004.
- PB 10-573-03 "Device rules and safe operation Pipelines steam and hot water. "
Depending on the conditions of the construction site, the design of networks can be conjugate with the reorganization of existing underground structures that interfere with construction. The design of thermal networks and the implementation of projects provides for the use of two isolated steel pipelines (feed and reverse) in special prefabricated or monolithic channels (passing and non-projective). To place disconnecting devices, rubbers, air and other fittings, the design of the heat networks is provided for the construction of cameras.
For design networksand their throughput, the problems of uninterrupted operation of hydraulic and thermal modes are relevant. By designing thermal networks, our company's specialists use the most modern methods, which allows us to guarantee a good result and durable work of all equipment.
By carrying out, it is necessary to rely on many technical standards, whose violation can lead to the most negative consequences. We guarantee compliance with all rules and rules governed by various technical documentation described above.
