RU2760610C1 - Heat pump system for utilizing waste heat of subway exhaust air - Google Patents

Abstract

FIELD: subway.

SUBSTANCE: invention relates to the subway, namely to installations for using waste heat of the exhaust air of the subway for the simultaneous production of hot and cold water and their use in heating systems, hot water supply and air conditioning for the subway's own needs. The heat pump 1 is located in the heating point 19 inside the metro station 24 with a double-track tunnel 25, under the roof of which the exhaust ventilation duct is located 20. Due to the operation of the heat pump 1, the low-potential heat of the exhaust air is converted into heat with a high temperature, which is transferred to the heat carrier circulating in pipelines 14 hot water circuit. The hot water circuit is divided through the heat accumulator 4 into the heating circuit 9 and the hot water circuit 10. When transferring heat in the evaporator of the heat pump 1, the heat carrier (propylene glycol) of the intermediate heat transfer circuit from the exhaust air is cooled and its refrigerating potential can be used for cooling systems of consumers located at the metro station 24. Objects located inside the metro station are used as heat and cold consumers.

EFFECT: increasing the efficiency of the heat pump, reducing the volume of construction work when installing a heat pump at a metro station and reducing the length of heat communications (pipelines) from the heat pump to consumers of thermal energy and cold.

1 cl, 3 dwg

Description

The invention relates to the subway, and in particular to installations for the use of waste heat of the exhaust air of the subway for the simultaneous production of hot and cold water and their use in heating systems, hot water supply and air conditioning for the subway's own needs.

The experience of operating subways shows that most often the main hazard is the heat entering the tunnels from the transformation of the energy of moving trains and the operation of equipment. Some of this heat interacts with the surrounding soil, and some is removed by the tunnel ventilation system. In practice, the secondary use of heat removed by tunnel ventilation does not find application for urban facilities due to the design features of underground structures, their autonomy and increased safety requirements, but does not exclude their use for the devices of the metro itself.

There is a known method and system for using waste heat from subways, which consists in extracting heat energy using a heat pump installation from a working substance that accumulates thermal energy of air heated from the movement of trains through a tunnel and from a power transformer, which is used as water accumulating in the tunnel (RF Patent No. 2194401, publ. Of 10/20/2002, bull. No. 29).

However, to implement this technical solution, groundwater is used as a source of low-grade heat, which enters the tunnel through the leaks of the tunnel lining. When using modern high-precision lining, moisture intake from the soil should be absent, which makes it impossible to use this method.

Known is the invention of the urban metro with zero consumption of thermal energy from external sources, which provides for the separation of the transport zone from the station platform by a partition with automatic doors and the placement of a heat pump in tunnel ventilation shafts operating in reversible modes depending on the position of the rolling stock (RF Patent No. 2672891 , publ. from 20.11.2018, bul. No. 32).

However, the implementation of this invention requires constant switching of tunnel ventilation shafts between direct and reverse operation depending on the position of the rolling stock, which leads to high wear of ventilation equipment and a significant complication of the control system.

A known subway ventilation system with a device for thermodynamic air treatment in the supply and exhaust shafts in the form of air-water heat exchangers connected by a pipeline to a common hydraulic circuit (RF Patent No. 2689967, publ. From 05/29/2019, bull. No. 16).

However, the use of this system limits the need for laying many kilometers of hydraulic circuits between the supply and exhaust shafts. In part of the schemes, it is proposed to use the thermal resource of groundwater entering the tunnel through the leaks of the tunnel lining, which is impossible when using modern high-precision lining due to the absence of leaks.

There is a known method of using the extracted geothermal heat to cool the soil around the metro tunnels and transform it to heat water in the hot water supply system (RF Patent No. 2683059, publ. From 03/26/2019, bull. No. 7).

However, for its implementation, a large amount of earthwork is required, as well as access to the outer vault of the lining, for laying the heat exchange circuits, which is difficult in the conditions of cramped urban development and leads to high costs.

There is a known ventilation method for metro lines with a double-track tunnel, under the roof of which a ventilation duct is provided, where the heat of the exhaust air was used to increase the temperature supplied to distill the supply air during the cold season. The method provides year-round supply of external air to the double-track tunnel through the supply ventilation shaft located at the station, and removal of the tunnel air from the double-track tunnel through the exhaust ventilation shafts. Outside air or a mixture (during the cold period) from the supply ventilation shaft is directed into the ventilation duct located in the upper part of the tunnel (under the roof), and then through the valve connecting the central part of the ventilation duct with the tunnel, air is passed into the tunnel with the possibility of organizing its movement along it in opposite directions. (RF patent No. 2594025, publ. Of 08/10/2016, bul. No. 22).

A known heat pump system for using waste heat from the subway, containing a heat pump including a closed circuit of the working fluid with an evaporator, a condenser and a compressor, tunnel fans removing the exhaust air from the subway line through an exhaust shaft and a heat exchanger-evaporator of the heat pump, which is installed in the exhaust shaft, and providing the transfer of low-grade thermal energy of the exhaust air to the working fluid of the heat pump, and a hot water circuit that transfers heat from the condenser of the heat pump to heat consumers (Patent for a useful model of the Russian Federation No. 120753, publ. dated 09/27/2012, bull. No. 27).

However, this technical solution does not use the refrigeration potential obtained by transferring the body to the working fluid of the heat pump, the heat pump and tunnel fans are installed on the section of the metro tunnel, which requires the construction of additional building volumes in the exhaust shaft, and the consumers of the heat received from the heat pump are ground facilities and metro facilities located at stations, which requires the creation of extended thermal communications (pipelines) from the exhaust shaft located on the section of the metro tunnel.

The technical result that can be obtained by implementing the invention consists in increasing the efficiency of the heat pump, reducing the volume of construction work when installing a heat pump at a metro station and reducing the length of heat communications (pipelines) from the heat pump to consumers of heat energy and cold.

To achieve this technical result, the proposed heat pump system for using the waste heat of the metro exhaust air, containing a heat pump, which includes a closed circuit of the working fluid with an evaporator, a condenser and a compressor, exhaust fans that remove the exhaust air from the metro line through heat exchangers-recuperators located in the exhaust shaft and providing the transfer of low-grade heat energy of the exhaust air to the working fluid of the heat pump, and a hot water circuit that transfers heat from the condenser of the heat pump to heat consumers, according to the invention, that the heat pump is located in a heat point inside a metro station with a double-track tunnel, under the arch of the passenger platform of which an exhaust ventilation duct is located, and is equipped with an intermediate circuit for transferring heat from the exhaust air to a heat pump with heat exchangers-recuperators installed in the exhaust ventilation duct of the station a tropolithic tunnel with a double-track tunnel and taking heat from the exhaust tunnel air passing through the evaporator of the heat pump and providing the transfer of low-potential heat energy of the exhaust air to the working fluid of the heat pump, a hot water circuit with an electric boiler that transfers heat from the condenser of the heat pump to the heat consumer and is separated through the heat accumulator to a heating circuit and a hot water supply circuit with a storage boiler, a cooling circuit passing through the evaporator of the heat pump and containing a battery tank connected in series with each other, to which the chiller is connected, and an intermediate heat exchanger through which a closed refrigeration supply system of the cold consumer passes, a cooling tower connected by pipelines with chiller and hot water circuit, while the intermediate circuit for transferring heat from the extract air to the heat pump and the cooling circuit operate in parallel, and use There are objects located inside the metro station.

Introducing a heat pump into the proposed heat pump system for using waste heat from the exhaust air of the subway, located in a heat point inside a metro station with a double-track tunnel, under the roof of which there is an exhaust ventilation duct, and supplying the heat pump system with an intermediate circuit for transferring heat from the exhaust air to a heat pump with heat exchangers - recuperators installed in the exhaust ventilation duct of a metro station with a double-track tunnel and taking heat from the exhaust tunnel air passing through the heat pump evaporator and providing the transfer of low-potential heat energy of the exhaust air to the working body of the heat pump, a hot water circuit with an electric boiler, providing heat transfer from the heat pump condenser to the heat consumer and divided through the heat accumulator into a heating circuit and a hot water supply circuit with a storage boiler, a cooling circuit passing through the heat pump unit and a storage tank connected in series with each other, to which the chiller is connected, and an intermediate heat exchanger through which a closed cooling system for the cold consumer passes, a cooling tower connected by pipelines with a chiller and a hot water circuit, while an intermediate circuit for transferring heat from the exhaust air the heat pump and the cooling circuit operate in parallel, and the use of objects located inside the metro station as consumers of heat and cold makes it possible to obtain a new property, which consists in increasing the efficiency of using the heat pump due to the simultaneous use for consumers of both heat from the heat pump condenser and and refrigeration potential from the heat pump evaporator, reducing the volume of construction work when installing a heat pump at a metro station by placing a heat pump inside the heat point of a metro station, which became possible by collecting exhaust air in the exhaust ventilation duct of a metro station with a double-track tunnel and placing heat exchangers-recuperators of the intermediate circuit in it for transferring heat from the exhaust air to the heat pump, as well as reducing heat communications (pipelines) due to the transfer of heat energy and cold from the heat pump only to consumers located at the metro station, along the hot water circuit, divided into a heating circuit and a hot water supply circuit, and along a cooling circuit associated with a closed refrigeration system for the cold consumer through an intermediate heat exchanger.

The invention is illustrated by drawings, where in FIG. 1 shows a cross-section of a metro station with a double-track tunnel, FIG. 2 is a schematic diagram of a heat pump system for using the waste heat of the metro exhaust air; FIG. 3 - unit for installing heat exchangers-recuperators in the exhaust ventilation duct of a metro station with a double-track tunnel.

1 - heat pump heat pumps, which includes a closed circuit of the working fluid with an evaporator, a condenser and a compressor (not shown in the figure);

2 - electric boiler of the hot water circuit;

3 - cooling tower;

4 - heat accumulator of the hot water circuit;

5 - chiller (refrigeration machine) of the cooling circuit;

6 - accumulator tank of the cooling circuit;

7 - heat exchangers-recuperators of the intermediate circuit for transferring heat from the exhaust air to the heat pump;

8 - storage boiler for the hot water supply circuit;

9 - heating circuit with heat consumer;

10 - hot water supply circuit with hot water consumer;

11 - closed-loop refrigeration system with a cold consumer;

12 - intermediate heat exchanger;

13 - pipelines of the intermediate circuit for transferring heat from the exhaust air to the heat pump;

14 - pipelines of the hot water circuit;

15 - make-up pipeline for the hot water supply circuit;

16 - pipelines of the cooling circuit to the accumulator tank;

17 - pipelines of the cooling circuit after the accumulator tank;

18 - pipelines for dumping heat into the cooling tower;

19 - heating point of a metro station with a double-track tunnel;

20 - exhaust ventilation duct of the metro station with a double-track tunnel;

21 - exhaust ventilation chamber;

22 - exhaust fans;

23 - an exhaust shaft of a metro station with a double-track tunnel;

24 - metro station;

25 - double-track underground line tunnel.

The proposed heat pump system for using the waste heat of the metro exhaust air works as follows.

The heat pump 1 is located in the heat point 19 inside the metro station 24 with a double-track tunnel 25, under the roof of which there is an exhaust ventilation duct 20. In the exhaust ventilation duct 20, heat exchangers-recuperators 7 of an intermediate circuit for transferring heat from the exhaust air to the heat pump 1 are installed, through which the exhaust fans 22 are pumped from the exhaust ventilation duct 20 of the metro station 24 with a double-track tunnel 25. Low-potential (low temperature) heat of the exhaust air from heat exchangers-recuperators 7 through pipelines 13 of the intermediate circuit for transferring heat from the exhaust air to the heat pump is transferred to the working body of the heat pump 1 through it evaporator (not shown in the figure).

Due to the operation of the heat pump 1, the low-grade heat of the exhaust air is converted into the heat of the working medium of the heat pump 1 with a high temperature, which is transmitted through the condenser of the heat pump to the heat carrier (water) circulating in the pipelines 14 of the hot water circuit.

The hot water circuit is additionally equipped with an electric boiler 2, which is used when it is necessary to heat up the heat carrier circulating in the pipelines 14 of the hot water circuit. The hot water circuit, which transfers heat from the condenser of the heat pump to the heat consumer, delivers hot water through pipelines 14 to the heat accumulator 4. Further, the hot water circuit is divided through the heat accumulator 4 into the heating circuit 9, which supplies hot water to the heat consumer for heating, and the circuit hot water supply 10 with a storage boiler 8, which supplies hot water to the consumer for hot water drawing. Through the make-up pipeline 15, the required amount of water is supplied to the boiler 8 of the hot water supply circuit to compensate for the DHW draw-off.

When transferring heat in the evaporator of the heat pump 1, the heat carrier (propylene glycol) of the intermediate circuit for transferring heat from the exhaust air is cooled and its refrigerating potential can be used for cooling systems of consumers located at the metro station 24.

For these purposes, the heat pump system, parallel to the intermediate circuit for transferring heat from the exhaust air to the heat pump, is equipped with a cooling circuit with pipelines 16 passing through the evaporator of the heat pump 1 and containing an accumulator tank 6 connected in series with each other, to which the chiller 5 is connected, and through pipelines 17 an intermediate heat exchanger 12, through which the closed cooling system of the cold consumer with the cold consumers 11 passes.

Exhaust fans 22 installed in the exhaust ventilation chamber 21 remove exhaust air from the ventilation duct 20 located under the roof of the metro station 24 with a double-track tunnel 25 through the exhaust shaft 23.

If necessary, heat is removed from heat pump 1 (in the case of temporary absence of hot water and heating consumers - summer mode) and chiller (refrigerating machine) 5 through the heat release pipelines 18 to the cooling tower 3, also installed in the exhaust ventilation duct 20.

Objects located inside the metro station are used as consumers of heat and cold.

Sources of information taken into account when preparing the application:

1. RF patent No. 2194401, publ. from 20.10.2002, bul. No. 29.

2. RF patent No. 2672891, publ. from 20.11.2018, bul. No. 32.

3. RF patent No. 2689967, publ. from 29.05.2019, bul. No. 16.

4. RF patent No. 2683059, publ. from 26.03.2019, bul. No. 7.

5. RF patent No. 2594025, publ. from 08/10/2016, bul. No. 22.

6. Patent for a useful model of the Russian Federation No. 120753, publ. from 27.09.2012, bul. # 27 - prototype.

Claims (1)

A heat pump system for using the waste heat of the metro exhaust air, containing a heat pump that includes a closed circuit of the working fluid with an evaporator, a condenser and a compressor, exhaust fans that remove the exhaust air from the metro line through heat exchangers-recuperators located in the air to the working fluid of the heat pump, and a hot water circuit that provides heat transfer from the condenser of the heat pump to heat consumers, characterized in that the heat pump is located in a heat point inside a metro station with a double-track tunnel, under the roof of the passenger platform of which there is an exhaust ventilation duct, and equipped with an intermediate circuit for transferring heat from the exhaust air to a heat pump with heat exchangers-recuperators installed in the exhaust ventilation duct of a metro station with a double-track tunnel and removing heat from the exhaust tunnel air passing through the evaporator of the heat pump and providing the transfer of low-potential heat energy of the exhaust air to the working fluid of the heat pump, a hot water circuit with an electric boiler, providing heat transfer from the condenser of the heat pump to the heat consumer and separated through a heat accumulator to a heating circuit and a hot water supply circuit with storage a boiler, a cooling circuit passing through the evaporator of the heat pump and containing an accumulator tank connected in series with each other, to which the chiller is connected, and an intermediate heat exchanger through which a closed cooling system of the cold consumer passes, a cooling tower connected by pipelines to the chiller and a hot water circuit, while the intermediate circuit for transferring heat from the extract air to the heat pump and the cooling circuit operate in parallel, and the objects located inside the metro station are used as consumers of heat and cold.

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