Useful information. Commissioning of heating systems

2. Introduction

This technical report contains materials on optimizing the operation of the heat supply system in the village of Podozersky.

The purpose of the work is: to study the throughput of heating networks in connection with the planned reconstruction of the heat source and calculate the optimal operating modes operation of the heat supply system, issuing recommendations for setting up heating network subscribers.

The results of the activities specified in the report, completed in full,

must be:

Reducing costs for own needs of boiler houses and costs associated with operation large number small boiler houses;

Promotion hydraulic stability operation of heating networks;

Creation required pressures at thermal inputs of consumers;

Consumption of estimated heat consumption by heating network subscribers;

Security comfortable conditions in the premises of heat consumers.

2. Description of the heating system

2.1 Heat source

The source of heat on the heating network is the boiler house of the Podozersky village. The boiler house currently runs on peat. It is planned to modernize equipment at heat sources in order to switch to another type of fuel - gas. The pressures at the outlet of the boiler houses were selected based on considerations of the minimum sufficiency of pressures at the subscriber inputs connected to this source, subject to commissioning - installation of restrictive throttling washers at all heat consumers. The throughput capacity and available power of the heat source were also not considered due to the lack of a boiler room reconstruction project.

Regulation of heat supply for heating is carried out according to a schedule of 95/70 C. As calculations have shown, the throughput of the networks in the village of Podozersky allows the selected temperature schedule to be maintained.

2.2 Heat networks

The heating networks of the Podozersky village are two-pipe, radial, and dead-end. It is possible to loop them (reconnect), if necessary, through the internal networks of the children's factory (N16-N49) The total length of the heating system heating networks is 5200 meters, the total volume of the heating system networks is 100.4 m3, heating consumption is 169 t/hour .

The volume of heating networks was determined by the formula

where V is the volume of the heating main section in a two-pipe design, m3;

L – length of the section, m;

D – internal diameter of pipes, m.

2.3 Consumers

Thermal consumers of the Podozersky village - a total of 80 inputs. There are no large industrial consumers.

All consumers are connected directly to the heating network.

Maximum thermal loads heating systems for administrative buildings and industrial buildings, in which there are no heating and ventilation installations, residential and public buildings, were determined by the formula:

, (2)

Sanitary standards" href="/text/category/sanitarnie_normi/" rel="bookmark">sanitary and hygienic standards SNiP 2.04.05-91.

Estimated flow network water to the heating system (HC) connected via dependent circuit, is determined by the formula:

Water temperature in the supply pipeline of the heating network at the design temperature of the outside air for heating design, °C;

Water temperature in the return pipeline of the heating system at the design temperature of the outside air for heating design, °C;

The total heating consumption taking into account the future (warehouse and tool shop) is 169 t/hour.

3. Initial data

Temperature chart for heating needs 95/70 oC.

The estimated water consumption in the heating network is 169 t/hour.

For distribution of loads among subscribers, see Appendices 3 – 5.

The geodesy of subscribers and the heat source is determined by the elevation marks of the area.

Heating network diagram, see Appendix 2

4. Hydraulic calculations

4.1 Hydraulic calculation with an available pressure at the source of 20 m.v. st

Hydraulic calculations were performed using specialized computer program"Bernoulli" has a certificate of official registration of the computer program No., registered in the Register of Computer Programs on October 11, 2007.

The program is designed to carry out verification and adjustment hydraulic and thermal calculations based on the compilation of a geographic information system - a diagram of a heating network on a map of the area and filling out a database of characteristics of heating mains, subscribers and sources. The task of hydraulic calculation of pipelines is to determine the pressure loss of each section and the amount of pressure loss for sections from the outlets of the heat source to each heat consumer, as well as to determine the expected available pressures at each subscriber.

Hydraulic calculation of an external water heating network is carried out on the basis of the roughness of pipelines, assumed to be 2 mm, since the duration of operation of most networks exceeds 3 years.

During commissioning, the necessary restriction devices (throttle diaphragms) for heat consumers are calculated due to the elevator-free system for regulating the heating load at customer inputs.

The pressures at the source were selected based on the following considerations. The available pressures (pressure difference in the supply and return pipelines) at the inputs for non-elevator connection of heat consuming systems must exceed the hydraulic resistance of local heat consuming systems; direct pressures should be minimal; return pressures must exceed the geodetic elevation by 5 meters plus the height of the subscriber’s heating system (building height).

To take into account the mutual influence of factors determining the hydraulic mode of the system district heating(hydraulic pressure losses along the network, terrain profile, height of heat consumption systems, etc.) a graph of water pressure in the network was constructed in dynamic and static modes (piezometric graph).

Using the pressure graph, the following were determined:

Required available pressure at the heat source terminals;

Available pressures at the inputs of heat consumption systems;

The need for relocation of individual sections of the network.

In order to determine the condition and throughput of the existing heating network, hydraulic and thermal calculations of the Podozersky village were performed on the existing heating loads with the following parameters.

The estimated water consumption in the heating network is 169 t/hour. Calculated available pressure at the inlet heating network- 20 m. Geodetic marks and pressures at the nodes of the heating network are adopted in a single reference system. To achieve this pressure is calculated in meters of water column. Working diagram heating network with coding of cameras and subscribers, compiled in accordance with the materials provided, is displayed in Appendix 3. Geodetic marks of the heating network nodes are taken from topographic map terrain along lines equal heights. The lengths of the routes are calculated based on the heating network diagram on a real scale. The internal diameters of pipelines are given to standard values.

Calculations were performed after adjustment calculations. Thus, it has not been studied current state network, and the state of the network in case of installing limit washers. For subscribers with light loads ( artesian well) it was not possible to establish heating consumption that corresponded to the contractual ones due to the ban on installing washers with hole diameters smaller than 3 mm due to the tendency of small holes to quickly become clogged. For these subscribers, to eliminate overflows, it is recommended serial connection with neighboring subscribers.

Table of required throttling devices (washers) for the option with an available pressure at the source of 20 m.v. Art. is given in Appendix 6.

Under such conditions, boilers network pumps and the existing heating network cope with the generation, supply and transport of the calculated amount of heat.

Calculation results (piezometer, and data table in Appendix 3).

4.2 Hydraulic calculation with available pressure at the source of 17 m.v. st

The calculated available pressure at the entrance to the heating network is 17 m. At many inputs to subscriber nodes, the available pressures are close to the internal resistance of subscribers. Conclusion - the pressure is the minimum required. For subscribers at Stationnaya 6 and 8, it is insufficient due to the insufficient diameter of the supply pipelines. This mode does not ensure the stability of the heating network. Calculation results (piezometer, and data table in Appendix 4).

4.3 Hydraulic calculation with available pressure at the source of 10 m.v. st

The estimated available pressure at the entrance to the heating network is 10 m. In this mode, subscribers are identified who are at risk of underheating due to a systematic underestimation of pressure at the outlet of the source. Calculation results (piezometer, and data table in Appendix 5).

4.4 Hydraulic calculation to identify problem areas and subscribers.

The calculated available pressure at the entrance to the heating network is 15 m. The diameters of the washers are left as for adjustment at 20 m. Art. In this mode, subscribers with addresses Station 6 (N14) and Station 8 (N17, N18) will be problematic. They are powered through pipes with a diameter of 50 mm that is insufficient for stable heat supply. The diameter should be replaced with 69 mm. The internal diameter of the pipes is indicated. The result of this reconstruction is illustrated by summary piezometers in Appendix 6. Subscribers of the dead-end branch on Sovetskaya Street 12, 14, 16 and the school building on the same street are most vulnerable to sufficient pressure at the exit from the boiler room. It is recommended to install pressure gauges, for example, in the heating unit of a school building to monitor the adequacy of the available pressure.

5. Main conclusions

The results of hydraulic calculations allow us to recommend adjusting heating networks to an available pressure at the outlet of the source of 20 m.w.s. in accordance with the table, calculation of throttling devices (washers), see Appendix 6.

To eliminate overheating for small subscribers, it is proposed to use a sequential scheme for connecting them through one thermal unit with one narrowing washer (throttle diaphragm). This connection scheme will allow you to bypass the difficulties associated with the restriction on the diameter of the restricting device - the washer (at least 3 mm, associated with the danger of frequent blockages).

Subscribers at 6 and 8 Stationnaya Street require the relocation of supply routes from the connection chamber with an internal diameter of 69 mm.

For status monitoring hydraulic mode Pressure gauges should be installed on the supply and return lines in the school building on Sovetskaya Street, as the most vulnerable part of the heating networks. You should also organize periodic monitoring of the readings of these pressure gauges.

For greater reliability of calculations in order to achieve optimal mode operation requires collecting more detailed information about the parameters of the heating network, source and consumer loads.

It should be noted that the calculation results are valid if, along with the reconstruction of heating mains, work is carried out to install washers at the subscribers' inputs that limit the coolant flow to the agreed value, and the internal heating systems of subscribers are also flushed. These activities must be carried out in accordance with the attached instructions (Appendix 1, 1a).

6. List of used literature

1. SNiP Construction climatology 01/01/2003

Application

INSTRUCTIONS

for flushing heating networks using a hydropneumatic method.

Currently used methods for flushing heat pipelines and heating systems, either by filling them with water and then releasing them into drainage, or by creating high water velocities in them through direct flow (discharge) or closed circuit(through temporary mud tanks) using network or other pumps do not give a positive effect.

IN lately heating networks of Mosenergo, Lenenergo and a number of other cities began to flush heat pipelines and local heating systems using compressed air.

The use of compressed air when flushing networks helps to increase the speed of the water-air environment and create high turbulence in its movement, which ensures the most favorable conditions for pressure from pipes of sand and other deposits.

Heat pipes are washed separate sections. The choice of the length of the flushed section depends on the diameter of the pipelines, their configuration and fittings.

For diameters D=100¸200 mm, you can use compensators with a capacity of 3–6 m3/min (for example, an AK-6 autocompressor with a capacity of 6 m3/min and an AK-3 with a capacity of 3 m3/min). For larger diameter pipelines, it is advisable to use two compressors or one compressor with higher capacity.

When flushing heating networks industrial enterprises It is possible to use compressed air from turbocompressors or compressor stations.

The duration of flushing depends on the degree and nature of contamination, as well as the diameter of the pipes and the performance of the compensator.

Before starting work, the pipeline (supply and return) is divided into sections, the boundaries of which are usually wells. In wells located at the beginning and at the end of the area to be washed, the valves are removed or partially dismantled and devices are installed in their place, with the help of which air is admitted and washing water is discharged.

The air intake devices are a flange made in the form of a flange connection of the removed fittings welded to it gas pipe Dy=38 ¸50 mm.

To regulate the air supply and protect the compressor receiver from water ingress, an appropriate valve is installed and check valve.

The device for selecting flush water consists of a short pipeline (riser) with a flange on one side corresponding to the flange of the removed fittings, and a valve on the other side, as well as a rigid hose that is connected to the valve and removed from the chamber (well).

If there are no valves on the pipeline being flushed, you can use valves on the branches. If both of these valves are missing, it is necessary to weld a temporary air fitting Dy=mm and a fitting for draining the flushing water. On pipelines with a diameter of up to 200 mm, the drain pipes must be at least Dy = 50 mm, with a diameter of Dy = mm – Dy = 100 mm, and with a diameter of 500 mm or more – Dy = 200 mm.

Water is supplied by a make-up pump through main pipelines, and the water should pass into the area to be washed from the compressed air supply side.

For flushing, water supply, network and process water. Areas are washed in the following order:

1) fill the area to be washed with water using a make-up pump and keep the pressure in it no more than 4 ati.

2) open the drain valve.

3) open the compressed air valve.

Incoming compressed air moves with water high speed, taking with it all contaminants into the drainage.

Flushing is carried out until the water coming out is clean.

When washing, the pressure of the washing water at the beginning of the section should be close to 3.5 ati, since more high blood pressure creates tension for the operation of the compressor, which usually operates at a pressure close to 4 ati.

The correct ratio of the quantities of water and air supplied to the pipeline is checked by the mixture movement mode.

The normal mode of movement of the mixture is considered to be one that is accompanied by pushes and slippages of alternately water and air.

Appendix a

INSTRUCTIONS

for flushing heating systems using hydropneumatic method

(suggested option)

Washing scheme

1,2,3,4 valves;

Required to install:

1. valve dy=25 – supply of network water;

2. check valve dy=25;

3. valve dy=32 – water-air supply to the heating system;

4. check valve dy=25;

5. valve dy=25 – air supply;

6. valve dy=25 – discharge into drainage, outside;

7. fittings for valve dy=25, 32, 25;

Before flushing the local heating system, you must do the following:

1. Install fittings for valves dy=25, 32, 25, as indicated in the diagram;

2. Assemble a flushing circuit with valves and check valves;

3. After flushing the heating system, plug the fitting (11).

Procedure for flushing the system.

1. Close valves 3 and 4 at the thermal input;

2. Fill the system with water through valves 5 and 7 (it is advisable that the system sit with water for at least 5 days before flushing). When filling with water, the vents must be opened. After filling the system, close the vents;

3. Start the compensator, open drain valve 10 and open valve 9 for air supply;

4. Flushing should not be carried out for the entire system at once, but separately in groups of risers (2 - 3 risers), the remaining risers must be turned off;

5. Rinse until clean water from the drain valve.

Note:

Washing can be done:

a) continuously with a constant supply of water, air and mixture discharge;

b) Periodically - with periodic supply of water and discharge of the mixture.

In relation to existing thermal inputs, the water-air supply assembly can be changed.

During the construction of a house, due attention must be paid to the installation and maintenance of the heating system. Only well-selected and correctly installed heating devices will ensure comfort in both residential and industrial premises. In addition, do not forget about timely technical support. And the organization boiler room will provide you with continuous access hot water, suitable for any needs, and will always contribute to the high-quality operation of the boiler. Whenever emergency situations and malfunctions, you must contact the technical maintenance service, whose qualified specialists will quickly adjust the operation of the boiler equipment. Uninterrupted operation once again proves high quality installation of the system.

Heating system repair

Home improvement should begin with a choice heating system, which most optimally combines the cost and quality of its work. First, a thorough analysis of the room selected for installation of the equipment is carried out. Next, a project is developed that takes into account the building parameters, type of layout and customer preferences. After the project is approved, they begin installation work. Currently, residents of the Moscow region pay a lot of attention to environmental problems, which is why they are increasingly choosing latest systems, not causing harm environment. No wonder that tired of the frantic pace modern life a person wants to make his home as cozy and comfortable as possible. It is for this that it is necessary to establish systems in accordance with all standards and rules, which will ensure proper safety of the devices during operation. Availability of service is also important technical support, whose specialists will always help you quickly and efficiently deal with system problems. System adjustment confirms that the design meets the requirements necessary for operation. It includes a thorough check of all system elements, correction of identified faults, and elimination of defects. Only professionals with certain skills and abilities can truly install heating correctly. Desire to save on installation costs by self-installation often leads to numerous breakdowns, and subsequent work to correct them is not cheap at all.

A set of measures for heating maintenance will allow you to assess the capabilities of the system, and, if necessary, adjust the parameters of its operation. The heating boiler is the basis of the heat supply system, and therefore requires timely maintenance and maintenance when using. The material that served as raw material in the manufacture of the boiler is the key to long service life without malfunctions. Trying to save money many people buy devices poor quality, which will not be able to serve as long as necessary. Cheap components can lead you down at any time.

Service

If you notice that on a cold day the radiators have suddenly cooled down and there is no hot water in the taps, do not hesitate to contact the technical support center for autonomous heating systems for help. The causes of such problems may be a blockage in the pipeline or a violation of the rules for operating the system. Qualified craftsmen can easily find and quickly eliminate the cause that has disrupted the comfort and coziness of your home.

Heating maintenance allows you to monitor the condition of the heating system. Not every homeowner knows that repairs are almost inevitable if all the rules are not followed. safe use technology. If you have any problems, try not to delay repairs. Failure to eliminate them in a timely manner may lead to accidents.

Hello! In this article I will consider a typical, let’s say, case of setup and adjustment internal system heating the building. Namely, heating systems with an elevator mixing unit. According to my observations, such ITPs (heating points) constitute approximately 80-85 percent of the total number of heating points. I wrote about the elevator in.

Setup elevator unit performed after commissioning ITP equipment. What does it mean? This means that for normal operation elevator at your heating point, the operating parameters from the heat supply organization for pressure and temperature in the supply pipeline (supply) P1 and T1 must be known. That is, the temperature in the supply T1 must correspond to the temperature according to the approved heating season temperature chart heat release. This schedule can and should be obtained from the heating supply organization; this is not a secret behind seven seals. In general, every heat energy consumer should have such a schedule. mandatory. This is the key point.

Then supply pressure P1. It must be no less than that required for normal operation of the elevator. Well usually heat supply organization It can still withstand the operating pressure of the supply.

Next, it is necessary that the pressure regulator, or flow regulator, or throttle washer were correctly adjusted and configured. Or as I usually say, “exposed.” I will write a separate article about this someday. We will assume that all these conditions are met, and we can begin setting up and adjusting the elevator unit. How do I usually do this?

First of all, I try to look at the design data on the ITP passport. I wrote about the ITP passport in. Here we are interested in all the parameters related to the elevator. System resistance, pressure drop, etc.

Secondly, I check, if possible, the correspondence between the fact and the working data from the ITP passport.

Thirdly, I look and check element by element the elevator, mud traps, shut-off and control valves, pressure gauges, thermometers.

Fourthly, I look at the pressure difference between the supply and return (available pressure) in front of the elevator. It must correspond or be close to the calculated one, calculated according to the formula.

Fifth, using pressure gauges after the elevator unit, in front of the house valves, I look at the pressure loss in the system (system resistance). They should not exceed 1 m.in. for buildings up to 5 floors, and 1.5 m.v.st. for buildings from 5 to 9 floors. This is in theory. But in fact, if you have a pressure loss of 2 m.v.st. and higher, problems are likely to arise. If you have a graduation scale on pressure gauges after the elevator unit in kgf/cm2 (a more common case), then you need to look at the readings like this: if on the supply side the pressure gauge reading is 4.2 kgf/cm2, then on the return side it should be 4.1 kgf/cm2. If the return is 4.0 or 3.9 kgf/cm2, then this is already an alarming signal. Of course, here you need to take into account that pressure gauges can give measurement errors, anything can happen.

Sixth, I check what the mixing ratio of the elevator is. I wrote about the mixing coefficient. The mixing coefficient must correspond to the calculated one, or be close in value to it. The mixing coefficient is determined by the coolant temperatures, which we take either from instantaneous heat meter readings or from mercury thermometers. Moreover, here it is necessary to take into account that the greater the temperature difference in the heating system, the more accurately the mixing coefficient can be calculated. Accordingly, the lower the temperature difference in the system, the higher the error in determining the elevator mixing coefficient may be.

Not often, but it happens that the pressure difference between the supply and return in front of the elevator (available pressure) is insufficient to ensure required coefficient mixing. This is, I would say, a difficult case. If the heating supply organization cannot (or does not want) to provide you with the required pressure drop, then most likely you will have to switch to a scheme with circulation pump.

After setting up the elevator unit, they begin setting up the heating system of the building. First, look at the wiring diagram of the heating system throughout the building (if there is one, of course). If not, I look at the heating distribution throughout the building visually. Although visual inspection necessary in any case. Here you need to find out which wiring is top or bottom, what heating devices are installed, whether they have control valves, whether there are balancing valves on the heating risers, thermostats on the heating devices, whether there are devices for removing air at the top points.

Setting up a heating system includes checking and adjusting the system both horizontally (distribution of coolant along risers) and vertically (distribution of coolant across floors).

First, we check the heating of the lower points of all risers. You can do this by touch. But in this case it is better that the water temperature is 55-65 °C. With more high temperature it is difficult to perceive the degree of heating. The lowest points of heating risers are usually located in the basement of the building. It’s good if at least some kind of control valves are installed on all risers. This is generally necessary, but unfortunately, it does not always happen in reality. It’s great if balancing valves are installed on the risers. Then we cover the overheating risers with control valves.

But it is better, of course, to check the distribution of water along the risers by measuring temperatures in the supply and return. Although this is a more labor-intensive option.

So, for example, the return temperature T2 in two-pipe system should be taken taking into account the cooling of the supply water temperature. If according to the graph T1 = 68 °C, and in fact T1 = 62 °C, T2 according to the graph is equal to 53 °C. In this case, the calculated temperature T2 = 62- (68-53) = 47 °C, not 53 °C.

In general, as a result of adjustment along the risers, there should be approximately the same temperature difference between the water at the inlet and outlet of all risers.

Very good thing for adjustment. It’s even better if you have thermostats installed on your heating appliances. Then the adjustment is made automatically. Temperature measurements heating devices carried out using a pyrometer.

The adjustment of the elevator unit and heating system is considered satisfactory if a uniform temperature is achieved in the heated rooms of the building.

I wrote a book on the topic of designing and setting up heating points “ ITP device(heating points) of buildings.” In it on specific examples I reviewed various schemes ITP, namely an ITP diagram without an elevator, a heating unit diagram with an elevator, and finally, a heating unit diagram with a circulation pump and adjustable valve. The book is based on mine practical experience, I tried to write it as clearly and accessible as possible. Here is the content of the book:

1. Introduction
2. ITP device, diagram without elevator
3. ITP device, elevator circuit
4. ITP device, circuit with a circulation pump and an adjustable valve.
5. Conclusion

Installation of ITP (heating points) of buildings