RU2769912C1 - Elevator unit control system with regulation of thermal energy consumption - Google Patents

Abstract

FIELD: heat engineering.SUBSTANCE: invention relates to the field of heat engineering, namely to the district heating of residential, public and industrial buildings, and can be used to control heat consumption in heating systems of buildings and structures. The effect is achieved due to the fact that in the elevator unit control system with regulation of thermal energy consumption based on a freely programmable controller with a data receiving and transmitting unit connected by channels for obtaining information with outdoor air and coolant temperature sensors and a channel for transmitting control commands through a frequency converter on the electric drive of the booster-mixing pump, it is proposed to introduce a check valve on the supply pipeline of the heating network. The system, if necessary, is additionally equipped with a circulation pump in the heating circuit or a booster pump in the circuit up to the elevator.EFFECT: increasing the reliability and efficiency of elevator units control with regulation of thermal energy consumption.5 cl, 5 dwg

Description

The invention relates to the field of heat engineering, namely the district heating of residential, public and industrial buildings, and can be used to control heat consumption in heating systems of buildings and structures. It is widely known that when heating buildings, it becomes necessary to switch from the temperature graph of the heating network (150/70°С, 130/70°С) to the temperature graph of the building heating system (95/70°С, 105/70°С). The transfer of thermal energy from the heating network to the heating system is carried out by changing the temperature of the coolant, which is set at the heat source (CHP, boiler house) depending on the outside temperature according to a given temperature schedule. For various reasons, heat sources can supply a heat carrier with an elevated temperature to the heating network both at sub-zero and positive outside air temperatures, which leads to increased consumption of thermal energy by consumers and overspending money to pay for heat. These excessive financial costs can be prevented by regulating the consumption of thermal energy in the consumer's heat supply system.

There are various technical solutions in this field.

For example, "AUTOMATIC CONTROL DEVICE FOR HEAT ENERGY CONSUMPTION (VERSIONS)" is known according to RF patent No. 2566943.

The automatic control device contains supply and return pipelines, an elevator and a heating system, as well as a pump, a control unit, an outdoor air temperature measurement unit, blocks. Control system for an elevator unit with regulation of heat energy consumption for measuring the temperature of the coolant installed on the supply and return pipelines. The control valve is installed in the supply pipeline, its outlet is connected to the first elevator inlet, and the inlet through the check valve is connected to the return pipeline. The circulation pump is connected with the inlet to the return pipeline, and with the outlet through the check valve it is connected to the outlet of the water jet elevator. Or a circulation pump is installed parallel to the return pipeline between the second inlet of the water-jet elevator and the second unit for measuring the temperature of the coolant. Or a circulation pump is installed parallel to the supply pipeline between the outlet of the water-jet elevator and the first unit for measuring the temperature of the coolant.

The disadvantage of the known device is the possibility of violation of the hydraulic mode of operation of the elevator in the process of weather regulation of the temperature of the coolant, which leads to a decrease in the reliability of the entire heat supply system.

It is also known a device with an elevator assembly (V.K. Ilyin. A low-cost solution for eliminating overheating in heating systems. News of heat supply No. 5 (May), 2011, pp. 45-50), containing a heating network supply pipeline connected in series with a regulator differential pressure, water-jet elevator, inlet pipeline of the heating system, heating system and return pipeline of the heating system and heating network, as well as a jumper in front of the elevator with a booster-mixing pump with a frequency-controlled electric drive and hydraulic input from the return pipeline through shutoff valves and hydraulic output through non-return valve and shut-off valves to the supply pipeline of the heating network after the differential pressure regulator, temperature sensors hardness salts and iron oxides on the surfaces of pipelines and heating appliances. Reduced circulation leads to uneven heating of the risers of the heating system, overheating of the premises of the upper floors of the building and underheating of the premises of the lower floors in the conditions of the upper filling of the heating system. The low quality of heat supply when using this elevator assembly is also due to the use of a “direct-acting” regulator as a differential pressure regulator, the principle of which is based on achieving a balance between the forces from the control diaphragm and the tuning spring. The operation of the "direct action" regulator is characterized by a large inertia, which leads to a significant uneven regulation of the consumption of thermal energy.

Also known is the patent of the Russian Federation No. 188210 "CONTROL SYSTEM OF THE ELEVATOR UNIT WITH REGULATION OF THERMAL ENERGY CONSUMPTION", which, as coinciding in most essential features with the proposed technical solution, is adopted by the authors as a prototype.

The well-known control system for an elevator unit with regulation of thermal energy consumption based on a differential pressure regulator and a freely programmable controller with dispatching functions, to which a frequency converter is connected for the booster-mixing pump electric drive, pressure sensors connected to the supply pipeline of the heating network after the differential pressure regulator and to return pipeline of the heating network, or a pressure drop sensor between these pipelines. In this case, the differential pressure regulator is made in the form of an electric control valve with a return spring and is also connected to a freely programmable controller.

The disadvantage of the prototype is the resulting in some cases, underestimated circulation of the coolant in the heating system of the building. Reduced circulation occurs with a relatively low available head of the heating network and / or with a relatively high hydraulic resistance of the heating system. Reduced circulation leads to uneven heating of the risers of the heating system.

Thus, the current technical problem is the lack of reliability and efficiency of existing control systems for elevator units with regulation of thermal energy consumption. The present invention is aimed at solving this technical problem, namely, at creating such a control system for elevator units with regulation of thermal energy consumption, which, on the one hand, would provide increased reliability during operation, and, on the other hand, provide efficient - with a sufficient level of circulation coolant - the operation of the heating system.

The technical result is to increase the reliability and efficiency of the control system for elevator units with the regulation of thermal energy consumption by providing an increase in the pressure drop in front of the elevator in the process of weather regulation and, as a result, an increase in the circulation flow of water in the heating system while reducing the amount of equipment used and reducing, respectively, costs. funds in the implementation of the management system.

The technical result is achieved due to the fact that the control system of the elevator unit with the regulation of thermal energy consumption is based on a freely programmable controller with a data receiving and transmitting unit connected by channels for obtaining information with outdoor air and coolant temperature sensors and a channel for transmitting control commands through a frequency converter to the electric drive of the booster-mixing pump is proposed to be made without a second control loop designed to maintain the pressure drop in front of the elevator at a constant level, since the installation of the differential regulator limits the upper value of the differential, because it is initially set in the controller. The proposed system automatically adjusts to the current pressure drop, the larger it is, the better.

At the same time, the first check valve is installed on the supply pipeline between the heating network input node and the jumper with the booster-mixing pump instead of the electric control valve.

In case of accidents on the supply pipelines of heating networks, the non-return valve prevents the heating system from being emptied, prevents the coolant from being squeezed from the return pipeline into the supply pipeline of the heating network, and also provides the ability to organize forced circulation of the coolant in the heating system with the help of a booster-admixture pump until the accident is eliminated on heating networks.

The system, if necessary, is additionally equipped with a circulation pump in the heating circuit, or a booster pump in the circuit up to the elevator.

Thus, the following technical elements are additional differences from the prototype:

- on the inlet pipeline of the heating system behind the water-jet elevator, a circulation pump can be installed, connected through shut-off valves, a filter and a second check valve and equipped with a bypass jumper with a third check valve.

- on the return pipeline between the heating system and the water-jet elevator, a circulation pump can be installed, connected to the pipeline through shut-off valves, a filter and a second check valve equipped with a bypass jumper with a third check valve.

- a booster pump can be installed on the inlet pipeline of the water-jet elevator, connected to the pipeline through shut-off valves and a second check valve and equipped with a bypass jumper with a third check valve.

- on the return pipeline between the water-jet elevator and the heating network input unit, a booster pump can be installed, connected to the pipeline through shut-off valves, a filter and a second check valve and equipped with a bypass jumper with a third check valve.

The essence of the invention is illustrated by the following graphics:

Fig. 1, which shows the first embodiment of the control system,

Fig. 2, which shows the second embodiment of the control system,

Fig. 3, which shows the third embodiment of the control system,

Fig. 4, which shows the fourth embodiment of the control system,

Fig. 5 showing a fifth embodiment of the control system.

Designations of positions on the figures:

1. Heating network input unit (gate valves, filters, thermometers, pressure gauges, heat energy metering unit, differential pressure regulator or flow limiter regulator, if necessary);

2. Freely programmable controller;

3. Block for receiving and transmitting data;

4. Coolant temperature sensor;

5. Outside air temperature sensor;

6. Frequency converter;

7. Supply pipeline of the heating network;

8. Check valve;

9. Water jet elevator;

10. Inlet pipeline of the heating system;

11. Heating system;

12. Return pipeline of the heating system and heating network;

13. Jumper between supply and return pipelines;

14. Boosting and mixing pump;

15. Electric drive;

16. Hydraulic input from the return pipeline;

17. Shut-off valves;

18. Filter;

19. Hydraulic output to the supply pipeline of the heating network;

20. Inlet pipeline of the water jet elevator;

21. Circulation pump;

22. Booster pump.

The proposed control system in contrast to the prototype:

- does not contain pressure sensors on the supply and return pipelines of the heating network, does not contain an electric control valve on the supply pipeline;

- contains a check valve 8 on the supply pipeline of the heating network 7.

The proposed system works as follows. In the event of an increase in the water temperature, measured by the coolant temperature sensor 4, compared to that required according to the temperature schedule of the heating system, the booster-mixing pump 14 is turned on with the output to the required capacity using the frequency converter 6 on commands from the freely programmable controller 2.

In this case, the following balance of water consumption is observed:

G _networks + G submix \ _u003d G elev \ _u003d G _dogs ,

where G _networks - water flow from the heating network;

G _admix - water flow in the jumper 13 between the supply and return pipelines, on which the booster-mixing pump 14 is installed;

G _elevator - water flow through the nozzle of the elevator (the inlet pipe of the elevator 20);

G _dogs - contractual consumption of water from the heating network.

At low outdoor temperatures, when the temperature of the water supplied to the heating system is not required, the pump 14 does not work.

In this case, the following equalities are observed: G _submix = 0 and G _networks = G _elev = G _dogs ,

In this case, if we neglect the slight pressure drop across the check valve, it can be argued that the pressure drop in front of the elevator 9 is equal to the available head of the heating network:

ΔP elev \ _u003d P ₁ -P ₂ ,

where _{ΔР elev} - pressure drop in front of the elevator;

P ₁ , P ₂ - pressure in the supply and return pipelines of the heating network, respectively.

When the outside air temperature rises, the pump 14 starts to work, however, the water pressure at the mixing point (or the pressure before the elevator) cannot exceed the pressure in the supply pipeline 7 P ₁ . If this happens, then the supply pipeline 7 will be blocked by the check valve 8, the flow of coolant from the heating network will stop, and the water temperature measured by sensor 4 will decrease, the speed and, accordingly, the pump head will also decrease.

Therefore, in the entire range of weather regulation ΔP _elev =P ₁ -P ₂ =const, and, accordingly, G _elev =const.

Thus:

G _net +G _submix =G _elev =const

At the same time, auto-hydraulic adjustment of the control system to the probable change in time of the water pressure drop in the heating network is provided with the achievement of the maximum possible values of the network water pressure drop in front of the elevator. As a result, a high level of water circulation in the heating system is ensured.

With a constant pressure drop in front of the elevator and the installed nozzle, the total flow rate of the coolant in the inlet pipeline of the elevator 20 remains constant. In addition, the mixing ratio remains constant over the entire control range:

U=Gper./Gcon.,

where U is the mixing ratio of the elevator (const);

Gnep. - water flow sucked by the elevator from the return pipeline.

With an increase in the speed of the pump 14 in accordance with the readings of the temperature sensor 4, G _submix increases, and G of the _network decreases, which implements the weather correction of the water temperature for heating.

When using the proposed control system, it is possible to achieve:

- an increase in the pressure drop in front of the elevator in the process of weather regulation and, as a result, an increase in the circulation flow of water in the heating system;

- reducing the amount of equipment used and reducing, respectively, the cost of funds in the implementation of the control system.

In practice, there is a situation when the pump circulation head ΔР _n transmitted by the elevator (water jet pump) to the heating system [Bogoslovsky V.N., Skanavi A.N. Heating. - M.: Stroyizdat, 1991 - 336 S.], is insufficient to overcome the hydraulic resistance of the heating system R _co , i.e. it turns out that ΔP _n <R _co .

This situation leads to a decrease in water circulation in the heating system and uneven heating of the risers of the heating system.

So, when the heating system is operating according to the temperature schedule of 95/70 ° С, the mixing coefficient is U = 2.2; with a temperature curve of 105/70°C: U=1.2 if the temperature curve of the heat source heating water is 150/70°C.

Taking ΔР elev \ _u003d P ₁ -Р ₂ , we have:

Thus, a decrease in water circulation in the heating system occurs if:

Such situations are possible with a relatively low available head of the heating network (P ₁ -P ₂ ) and/or a relatively high hydraulic resistance of the heating system R _co .

To prevent this situation, the control system is equipped with additional pumps.

It is possible to install circulation pumps on the inlet or return pipelines of the heating system, ensuring consistent operation with the elevator (water jet pump) to compensate for the lack of circulation pressure to overcome the hydraulic resistance of the heating system (see Fig. 2 and Fig. 3). At the same time, the elevator provides a constant mixing ratio, and the circulation pump compensates for the lack of pressure.

It is possible to install booster pumps on the supply (inlet) or return pipelines to the elevator to increase the pressure drop in front of the elevator, providing an increase in the circulation head of the elevator (see Fig. 4 and Fig. 5).

The system is additionally equipped with a circulation or booster pump only if necessary, if:

In the event of emergencies (power failure, breakage of communication lines with temperature sensors), the booster-mixing pump 14 is turned off, and the check valve 8 opens completely. After the emergency situation is eliminated, the control system automatically switches to the normal mode of operation with the previous settings.

Remote dispatching of the control system is provided via communication channels, for example, via the Internet, Ethernet, cellular communication. The freely programmable controller 2, using the data receiving and transmitting unit 3, transmits the controlled parameters via communication channels to the server running the SCADA system.

All basic settings of the free-programmable controller 2 can be changed from the control room, including the PID gain, the heating system temperature curve, and the temperature curve offset.

As a controller, as an option, a microprocessor free-programmable controller MC12 of the Kontar Software and Hardware Complex (PTC) of MZTA JSC (Moscow Thermal Automation Plant) with an interface module for receiving and transmitting data (Weblinker), which has the functions data protection (encryption and access restriction) and ensures the transfer of information about the parameters of the control system via the Internet to the global server of MZTA JSC.

As a check valve, as an option, a spring poppet check valve from DANFOSS (Denmark) can be used.

Pumps from WILO, GRUNDFOS (Germany) or analogues can be used as booster-mixing, circulation and booster pumps.

The expected savings in thermal energy for heating needs in the implementation of the claimed invention is at least 25%, which is confirmed by the experience of operating the control system at the facilities of St. Petersburg.

The use of the claimed invention allows for more efficient and reliable operation of the heat supply system both in a wide range of changes in external weather conditions, and in case of emergencies.

Claims (5)

1. Control system for an elevator unit with regulation of thermal energy consumption based on a freely programmable controller with a data receiving and transmitting unit, connected by channels for obtaining information from outdoor air and coolant temperature sensors and a channel for transmitting control commands through a frequency converter to an electric drive of a booster-mixing pump, characterized in that it contains the first check valve on the supply pipeline of the heating network between the input node of the heating network and the jumper with the booster-mixing pump. 2. The elevator unit control system according to claim 1, characterized in that a circulation pump is installed on the inlet pipeline of the heating system behind the water-jet elevator, connected through shutoff valves, a filter and a second check valve and equipped with a bypass jumper with a third check valve. 3. The elevator unit control system according to claim 1, characterized in that a circulation pump is installed on the return pipeline between the heating system and the water jet elevator, connected to the pipeline through shutoff valves, a filter and a second check valve and equipped with a bypass jumper with a third check valve. 4. The elevator assembly control system according to claim 1, characterized in that a booster pump is installed on the inlet pipeline of the water jet elevator, connected to the pipeline through shutoff valves and a second check valve and equipped with a bypass jumper with a third check valve. 5. The elevator unit control system according to claim 1, characterized in that a booster pump is installed on the return pipeline between the water jet elevator and the heating network input unit, connected to the pipeline through shutoff valves, a filter and a second check valve and equipped with a bypass jumper with a third check valve .

Images