JPH0124527Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an exhaust heat utilization system.

Although the amount of waste heat generated by subways is enormous, the total amount of waste heat is not utilized much.

This invention was proposed in view of these circumstances, and aims to provide a waste heat utilization system for subways, etc., in which the waste heat of relatively low-temperature air generated in each dispersed area can be used in each region. A plurality of distributed waste heat recovery units collect the liquid medium using an air heat source heat pump and convert it into a liquid medium with high transfer efficiency, and a water heat source heat pump and a waste steam heat exchanger collect the liquid medium from the plurality of distributed waste heat recovery units. , and a centralized exhaust heat recovery section that heats the exhaust gas to a predetermined temperature using an exhaust gas heat exchanger.

An embodiment of the present invention will be explained with reference to the drawings.
Figure 1 is its system diagram.

In the above diagram, 1 is a station building for the subway line, 2 is an exhaust tower installed at the midpoint between adjacent station buildings and provides ventilation in the subway, 3 is an air heat exchanger, 4 is a compressor, 5 is a condenser, and 6 is a compressor. Electric motor driving 4, 7, 8,
9 is a refrigerant communication pipe, 10 and 11 are cooling water communication pipes, and 3
~ 11 work together to form an air source heat pump, and the heat pumped up by each air source heat pump is attached to each exhaust tower 2 in the form of hot water, and is sent to the concentration center described later through the distribution main pipe 13 and the central transfer pipe 12. It will be done.

14 is an evaporator, 15 is a compressor, 16 is a condenser,
17, 18, and 19 are refrigerant pipes, and 14 to 19 cooperate to constitute a water heat source heat pump. 20 is a return pipe from the region to the central center, 21 and 27 are hot water communication pipes, 28 is a supply pipe to the region, 22 is a boiler, 23 is a turbine, 24 is a condenser, 25 is an exhaust gas heat exchanger, and 26 is a Chimneys, 29, 30, 31 steam communication pipes, 32 fuel supply pipes, 33, 34 flues, 35 air conditioning heat radiation equipment for each station building, 36, 37
is a hot water connection pipe.

In such a device, exhaust gas dispersed in a station building, tunnel, etc. is induced by an induction fan built into the air heat exchanger 3, and the exhaust gas and the refrigerant of the air heat source heat pump exchange heat in the air heat exchanger 3. This allows waste heat to be recovered.

The cycle of the air source heat pump consists of a process in which the air heat exchanger 3 heats and vaporizes the refrigerant using the sensible heat of the exhaust gas, passes through the refrigerant communication pipe 7, reaches the compressor 4, and condenses and liquefies it with cooling water. In other words, the temperature of the cooling water increases by an amount corresponding to the amount of heat collected by the air heat exchanger 3 plus the work required for compression.

The refrigerant liquefied in the condenser 5 reaches the air heat exchanger 3 via the refrigerant communication pipe 9, completing the cycle.

The number of air source heat pumps is the same as the number of exhaust towers, and if N is the number of station buildings, the number of air source heat pumps is approximately (N-1). This means that the gaseous and dispersed waste heat is recovered in the dispersed areas, converted into a medium of hot water with good transfer efficiency, and collected in a centralized center through the central transfer pipe 12.

This cooling water becomes the heat source for the evaporator 14 of the water heat source heat pump installed in the central center, and since its temperature level is 30 to 45°C, which is sufficient for simple heating, it is transferred from the central transfer pipe 12. As appropriate, the hot water is branched into a hot water communication pipe 36, used for heating in an air conditioner 35 installed in the station building 1, etc., and returned to the distribution pipe 13 through a connecting pipe 37.

The water source heat pump cycle consists of vaporizing the refrigerant heated by cooling water in the evaporator 14, passing through the refrigerant connecting pipe 17 to the compressor 15, compressing it to a predetermined pressure, and passing through the refrigerant connecting pipe 18 to the condenser 16. It consists of a process in which it is cooled and liquefied and condensed using hot water returned from the area. In other words, the return pipe 2 from the area corresponds to the total amount of heat that is recovered by the air source heat pump in the distributed area and further heated up, plus the work required for compression.
The temperature of the hot water returned after passing through 0 will be increased.

The refrigerant liquefied in the condenser 16 is transferred to the refrigerant communication pipe 19.
The cycle is completed through the evaporator 14.

The hot water heated in the condenser 16 enters the heat exchanger 24 via the hot water communication pipe 21, where it is heated by the exhaust gas of the turbine 23, and further passes through the hot water communication pipe 27 for exhaust gas heat exchange. The water reaches the boiler 25, is heated and heated by boiler exhaust gas, and is supplied to the region through the regional supply pipe 28.

On the other hand, in the turbine system that drives the compressor 15,
Steam is generated by combustion of the fuel supplied to the fuel supply pipe 32 in the boiler 22, and the steam passes through the steam communication pipe 29, drives the compressor 15 in the turbine 23, and is condensed through the steam communication pipe 30. Vessel 2
4 and further condensed through the connecting pipe 31 to the boiler 22.
Return to

Further, the exhaust gas from the boiler 22 passes through the flue 33 to the exhaust gas heat exchanger 25, exchanges heat with hot water, and is then discharged from the flue 34 to the atmosphere via the chimney 26.

According to the present invention, the following effects can be achieved by distributing primary air heat source heat pumps to distributed exhaust heat sources such as subways and exhaust towers between station buildings and recovering heat in a hot water state.

(1) It is more economical and has less heat loss than the case where exhaust gas is concentrated in a duct or the like and heat is recovered.

(2) The temperature of the hot water during the process of being led from the primary air heat source heat pump to the central center via the central transfer pipe is approximately 30 to 45°C, but this temperature is sufficient for station building heating, etc. By branching from the pipe and providing station building heating, etc., it is also possible to economically supply distributed loads.

(3) The hot water temperature obtained by the primary air heat source heat pump can be supplied at an almost constant level regardless of load fluctuations due to seasonal fluctuations, etc., and the disturbance elements of the water heat source heat pump, which performs secondary high temperature drop operation, can be reduced and stable operation can be achieved. Contribute to

In the secondary water heat source heat pump system, the following effects can be achieved by driving the back pressure turbine and installing the condenser on the outlet side of the heat pump condenser.

(1) The temperature of hot water supplied in centralized district heat supply is
The temperature is around 100 to 150°C, but the heat pump cycle is a reverse Carnot cycle, and the system number (ratio of pumped heat/required power) differs depending on the high temperature side.

By arranging the back pressure turbine condenser on the condenser outlet side, the temperature on the high temperature side of the heat pump cycle can be lowered and cycle efficiency can be increased.

(2) All of the exhaust heat from the back pressure turbine cycle can be converted into usable heat.

(3) When a Freon system is used as the working fluid for a heat pump cycle, thermal decomposition occurs at around 110 to 120°C, causing problems such as equipment corrosion. The outlet hot water temperature can be kept within a safe range.

The overall system of this method has the following effects compared to conventional centralized district heat supply equipment.

Compared to the conventional method that uses a boiler to produce high-temperature water, the energy supplied to the boiler is reduced.
If it is 1.0, the usable high-temperature water energy will depend on the boiler efficiency, and if it is less than 1.0, the exergy efficiency of the steam generated will deteriorate significantly.

However, in the case of this method, the heat pump action of the exhaust heat is recovered at a higher rate than the conventional heat utilization rate, and the total available heat amount is about 1.2, which means that about 20% more heat can be obtained than the input energy. .

In short, according to the present invention, a plurality of distributed waste heat recovery sections are used to collect the waste heat of relatively low-temperature air generated in each dispersed region using an air heat source heat pump in each region, and convert it into a liquid medium with high transfer efficiency. , by comprising a centralized exhaust heat recovery unit that collects the liquid medium from the plurality of distributed exhaust heat recovery units and heats it to a predetermined temperature using a water heat source heat pump, an exhaust steam heat exchanger, and an exhaust gas heat exchanger, The present invention is extremely useful industrially because it provides an economical waste heat utilization system for subways and the like.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention. 1... Station building, 2... Exhaust tower, 3... Air heat exchanger, 4... Compressor, 5... Condenser, 6... Electric motor, 7, 8, 9... Refrigerant communication pipe, 10, 11 ……
Cooling water communication pipe, 13... Distribution main pipe, 14... Evaporator, 15... Compressor, 16... Condenser, 17, 1
8, 19... Refrigerant piping, 20... Return pipe, 21...
... Hot water communication pipe, 22 ... Boiler, 23 ... Turbine, 24 ... Condenser, 25 ... Exhaust gas heat exchanger, 26 ... Chimney, 27 ... Hot water communication pipe, 28 ...
... Supply pipe, 29, 30, 31 ... Steam communication pipe, 3
2... Fuel supply pipe, 33, 34... Flue, 35...
...Radiation equipment for air conditioning, 36, 37...Hot water connection pipe.

Claims (1)

[Scope of utility model registration request] A plurality of distributed waste heat recovery sections that collect the waste heat of relatively low-temperature air generated in each dispersed region using an air heat source heat pump in each region and convert it into a liquid medium with good transfer efficiency, and a plurality of distributed waste heat An exhaust heat utilization system characterized by comprising a centralized exhaust heat recovery section that collects a liquid medium from a recovery section and heats it to a predetermined temperature using a water heat source heat pump, an exhaust steam heat exchanger, and an exhaust gas heat exchanger.