JPH0340304B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat pump system mainly used for heating and cooling buildings, factories, etc.

In recent years, heat pump-based heating and cooling systems (heat pump systems) are often used for heating and cooling buildings, factories, etc. This system is normally driven by an electric motor, but recently an engine-driven system has been developed and put into practical use. This engine-driven system can reduce running costs by 30-50% compared to conventional heating and cooling systems using boilers and refrigerators.
Therefore, although it is extremely useful in achieving energy conservation, it has the drawback of high initial cost, which is a factor that hinders its widespread use.

FIG. 1A is a diagram showing a schematic configuration of a conventional engine-driven heat pump system. In this figure, numeral 1 is a heat exchanger that exchanges heat between water and refrigerant (fluorocarbon gas), 2 is a compressor that compresses refrigerant gas, 3 is an air heat exchanger that exchanges heat between air and refrigerant gas, 4 is an expansion valve that adiabatically expands the refrigerant; 5
is the engine that drives the compressor 2, and 6 is the engine 5
7 is a heat exchanger that recovers heat generated in the exhaust gas of the engine 5; 8 is a heat exchanger that recovers heat generated in the exhaust gas of the engine 5;
~11 is a header, 12 and 13 are pumps, 14 and 1
5 is a four-way valve that changes the refrigerant circuit, and 16 is a liquid receiver that stops the liquefied refrigerant.

In the following configuration, when producing cold water for air conditioning, the heat exchanger 1 functions as an evaporator, and
Air heat exchanger 3 functions as a condenser. That is, the refrigerant passing through the heat exchanger 1 absorbs heat from the water sent by the pump 13, vaporizes, and is sent to the compressor 2 as refrigerant gas. The compressor 2 compresses the refrigerant gas and sends it to the air heat exchanger 3 as a high temperature and high pressure refrigerant gas. The refrigerant gas sent to the air heat exchanger 3 releases heat into the air and liquefies it. This liquefied refrigerant gas undergoes adiabatic expansion in the expansion valve 4, becomes a low-temperature, low-pressure refrigerant, and returns to the heat exchanger 1. Thus, the water supplied to the header 10 is cooled in the heat exchanger 1 and sent to the header 11 as cold water for cooling.

On the other hand, the water supplied to the header 9 is sent to the heat exchangers 6 and 7 by the pump 12, where it absorbs the heat generated from the engine 5 and the heat in the exhaust gas of the engine 5 to become hot water, and is then sent to the header 8. Sent. This hot water is used for hot water supply or space heating.

Next, when producing hot water for heating, the refrigerant circuit is changed using the four-way valves 14 and 15, as shown in FIG. 1B. In this case, the heat exchanger 1 functions as a condenser, and the air heat exchanger 3 functions as an evaporator. That is, refrigerant gas that absorbs heat in the air and vaporizes in the air heat exchanger 3 is compressed in the compressor 2, and is liquefied in the heat exchanger 1 by releasing heat. The water sent to the heat exchanger 1 by the pump 13 absorbs the heat released by the refrigerant gas in the heat exchanger 1 and becomes hot water.
sent to.

By the way, since the conventional heat pump system described above uses the air heat exchanger 3, there are various problems as follows.

Price becomes expensive.

The external shape of the air heat exchanger 3 is large, and therefore,
Requires a large footprint.

Efficiency decreases when the outside temperature is low, and in extreme cases it becomes unusable.

Usually, the air heat exchanger 3 is installed on the roof of a building, and the compressor 2, heat exchanger 1, etc. are installed in the basement, and long refrigerant piping is required. Note that, since the refrigerant pipes allow fluorocarbon gas to pass through them, they are more expensive than water pipes and are also difficult to construct, and therefore, long refrigerant pipes are extremely undesirable.

This invention provides a heat pump system that can solve all of the above problems, and includes a heat exchanger that exchanges heat between a medium such as water and a refrigerant instead of an air heat exchanger, and It is characterized by providing a cooling tower for cooling the medium.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a diagram showing the configuration of a heat pump system according to the present invention. In this diagram, parts corresponding to those in FIG. In Figure 2,
A heat exchanger 16 is provided in place of the air heat exchanger 3 in FIG. 1A, and is used to exchange heat between the refrigerant and water. Further, 17 is a cooling tower, 18 and 30 are pumps, 19 is a heat exchanger (third heat exchanger) for exchanging heat between water, and 20
28 are valves for opening and closing the pipes, respectively.

In the system shown in this figure, when producing cold water for air conditioning, the valves 20, 22, and 26 are each opened, and the valves 21, 23, 24, 25, 27, and 28 are each closed. As a result, the conduit indicated by the broken line becomes unused. In this case, the water (non-controlled body) supplied to the header 10 is pumped 1
3 to the heat exchanger 1 through the heat exchanger 19, where it is cooled and then sent to the header 11. The cold water sent to this header 11 is used for cooling. Note that in this case, the valve 27 is in a closed state, so no heat exchange is performed in the heat exchanger 19. The refrigerant that absorbs the heat of water and vaporizes in the heat exchanger 1 is compressed by the compressor 2, and is liquefied by releasing heat in the heat exchanger 29. Heat released from the refrigerant in the heat exchanger 29 is absorbed by water (medium) passing through the heat exchanger 29. The warmed water absorbing heat from the refrigerant is sent via valve 20 to cooling tower 17 where it is cooled. This cooled water is then sent to the heat exchanger 29 again by the pump 18 via the valve 22.

In this way, when producing cold water, the refrigerant absorbs the heat of the water in the heat exchanger 1 and releases the absorbed heat in the heat exchanger 29. That is,
In this case, the heat exchanger 1 functions as an evaporator, and the heat exchanger 29 functions as a condenser.

On the other hand, the water (medium) supplied to the header 9 is transferred to the pump 12 as in the case shown in FIG.
is sent to heat exchangers 6 and 7, where waste heat from engine 5 is recovered and turned into hot water, which is then sent to header 8.
supplied to This hot water is used for heating or hot water supply.

Next, the case of producing hot water for heating will be explained with reference to FIG. 3. In this case, the valves 20, 22, 26 are closed, and the valves 21, 2 are closed, contrary to when producing cold water.
3, 24, 25, 27, and 28 are opened. As a result, the conduit indicated by the broken line in FIG. 3 becomes unused. Further, in this case, the heat exchangers 1 and 29 function as an evaporator and a condenser, respectively, at the same time as producing cold water.

That is, the water (non-controlled) supplied to the header 9 is sent to the heat exchanger 29 via the valve 25, pump 30, and valve 23, where it absorbs the heat released from the refrigerant and converts it into hot water. Become. A portion of this hot water is further sent to the heat exchangers 6 and 7 via the valves 21 and 24 and the pump 12 to be warmed and supplied to the header 8, and a portion is directly supplied to the header 8. The hot water supplied to the header 8 is used for heating and hot water supply, and a portion of it is sent to the heat exchanger 19. On the other hand, the refrigerant that releases heat and liquefies in the heat exchanger 29 undergoes adiabatic expansion in the expansion valve 4 to become a low-temperature, low-pressure refrigerant, and is supplied to the heat exchanger 1 .
The refrigerant supplied to the heat exchanger 1 absorbs heat from the water passing through the heat exchanger 1 and is vaporized to become refrigerant gas, which returns to the heat exchanger 16 via the compressor 2. The water cooled in the heat exchanger 1 is transferred to a header 11,
It is sent to the heat exchanger 19 via the valve 28, the header 10, and the pump 13, where it is heated by the hot water supplied via the header 8, and returns to the heat exchanger 1 again. The hot water supplied from the header 8 to the heat exchanger 19 releases heat to the water supplied via the pump 13 in the heat exchanger 19, and then is supplied to the header 9 via the valve 27. It is sent to the heat exchanger 29 via the valve 25, pump 30, and valve 23.

Note that when cooling is performed at the same time as heating (in a building, etc., rooms in the center of the building may be cooled and rooms in the outer periphery may be heated), the valve 28 is closed and the header 11 is heated. Cold water can be used for cooling. In this case, depending on the temperature of the water supplied to the header 10, the amount of hot water supplied from the header 8 to the heat exchanger 19 can be reduced or made zero.

The above are details of one embodiment of the present invention shown in FIGS. 2 and 3. According to this example, during cooling, the coefficient of performance (COP) for chilled water production is 1.3,
A high coefficient of performance of 0.5 due to waste heat recovery from engine 5 and a total of 1.8 can be obtained. In addition, during heating, when there is only hot water demand, a coefficient of performance of 0.8, which is almost the same as that of a boiler, is obtained, and when there is also cold water demand, the coefficient of performance for hot water production is 0.8.
1.8, the coefficient of performance for cold water production is 1.0, and a high coefficient of performance of 2.8 in total can be obtained.

Note that this system can of course also use an air heat exchanger.

As explained above, according to the present invention, a heat exchanger that performs a heat exchange between water (medium) and a refrigerant is provided in place of the air heat exchanger in a conventional heat pump system, and the air is passed through the heat exchanger. By installing a cooling tower to cool the water used, the following advantages can be obtained:

Compared to engine-driven heat pumps using conventional air heat exchangers, the price can be reduced by 30-50%.

Compared to installing an air heat exchanger, the external installation area can be reduced to less than half.

It can be used satisfactorily even when the outside temperature is low.

Both the first and second heat exchangers can be installed in the basement, and only the cooling tower can be installed on the roof, and as a result, the refrigerant piping can be extremely short.

Compared to a heat pump system using an air heat exchanger, the coefficient of performance when producing chilled water is improved.

It goes without saying that according to the present invention, running costs can be significantly reduced compared to conventional heating and cooling systems using boilers and refrigerators.

In particular, with the present invention, it is possible to freely adjust the amount of cooling and heating by changing the engine speed and controlling the capacity of the heat pump in response to fluctuations in the cooling and heating loads. case,
It is now possible to operate only for cooling or only for heating.
In cooling, warm heat is released into the atmosphere in a cooling tower, but in heating, waste heat recovered from the engine can be sent to the cold water side of a heat pump, and the engine output and the amount of heat generated by this recovered waste heat can be used for heating. It produces excellent effects.

[Brief explanation of the drawing]

Figures 1A and 1B are both schematic configuration diagrams showing an example of a conventional heat pump system, in which Figure 1A shows the configuration when producing cold water, Figure 1B shows the configuration when producing hot water,
3 and 3 are both schematic configuration diagrams showing the configuration of an embodiment of the present invention, and FIG.
The figure is a diagram showing the configuration during hot water production. 1... Heat exchanger (first heat exchanger), 2... Compressor, 4... Expansion valve, 16... Liquid receiver, 17...
Cooling tower, 29... heat exchanger (second heat exchanger).

Claims (1)

[Claims] 1 A first heat exchanger that evaporates a refrigerant, an engine-driven compressor that compresses the refrigerant vaporized by the first heat exchanger, and an engine-driven compressor that compresses the refrigerant compressed by the compressor. a second heat exchanger for condensing, an expansion valve for adiabatically expanding the refrigerant liquefied by the second heat exchanger and supplying the refrigerant to the first heat exchanger, and cooling a non-controlled body. a cooling tower for cooling a medium passing through the second heat exchanger; a waste heat recovery circuit for recovering waste heat of the engine through the medium; and a cooling tower for cooling a medium passing through the second heat exchanger; and a third heat exchanger capable of exchanging heat with a non-controlled body passing through the heat exchanger, and when cooling the non-controlled body, the non-controlled body is cooled by the first heat exchanger. The medium passing through the second heat exchanger is supplied to the cooling tower for cooling, while when heating the non-controlled body, the non-controlled body is moved through the second heat exchanger. A heat pump system, characterized in that at least a part of the medium of the waste heat recovery circuit is caused to flow through the heat pump and flow into the non-controlled body.