JPS6255587B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat pump device using a compressor, and more particularly to a heat pump device using a heat engine as a drive device for the compressor.

In conventional heat pump devices, particularly those used for general household use, a compressor for compressing a refrigerant such as Freon is driven by an electric motor. With the spread of such heat pump devices, the amount of electric power required for them has also increased, and the need to reduce power consumption has recently become a social issue. Furthermore, taking as an example the case where a conventional heat pump device performs heating using outside air as a heat source, the energy sources required are approximately as follows.

In other words, in order to obtain a heating heat amount of 100, the required power is approximately 25 with a coefficient of performance (COP) of 4.
It is. Now, if we were to generate this electricity from fossil fuels such as petroleum, in order to be able to receive this amount of electricity for a typical household, the primary energy would need to be at least 25÷, taking into account power generation efficiency, transmission and substation losses, etc.
Fossil fuels with a calorific value of 0.3=83 must be used. This fossil fuel requirement will be less than the value shown above when the outside temperature is high, but will increase considerably when the outside temperature drops and heating becomes essential. In other words, it has the troublesome characteristic of reducing the energy efficiency of heat pump heating.

This invention was made in consideration of the above points, and it is arranged so that two compressors are driven by a heat engine, and further, the compression ratio of one of these compressors is smaller than that of the other. By adding a means for adjustment, the power required is extremely low.
It also enables a heating and cooling device with high energy efficiency.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a system diagram for explaining the configuration of this embodiment, and the following description will be made assuming that heating operation is being performed unless otherwise specified. In the figure, 1 is a first compressor, 2 is a second compressor,
The first compressor is operated at a lower compression ratio than the first compressor.
(However, during cooling, it is operated at the same compression ratio as the first one.) 3 and 4 are four-way valves, 5 to 8 are refrigerant pipes, and the arrows in the figure indicate the flow direction of the refrigerant. .
9 is a refrigerant confluence point, 10 is a finch tube indoor heat exchanger (condenser), 11 is a branch point, 12 is a first expansion means such as a capillary tube or an expansion valve, and 13 is a first outdoor heat exchanger. The exchanger removes heat from the outside air and evaporates the refrigerant.
Reference numeral 14 denotes a second expansion means having a pressure control function, which is configured to have a smaller resistance coefficient than the first expansion means 12. Reference numerals 141 and 142 are capillary tubes or expansion valves constituting the second expansion means 14, and 143 is an on-off valve of a pipe provided to allow refrigerant to flow bypassing the expansion valve 141, that is, a pressure control function. It opens when the air conditioner is on, and closes when it cools down.
15 is a second outdoor heat exchanger (evaporator) that uses the exhaust heat of the heat engine as a heat source. (However, in the cooling operation, the heat engine exhaust heat etc. can be released to the outside air.) 16 is a heat engine, and the compressors 1 and 2 are driven by the heat engine 16.

FIG. 2 is a state diagram of the refrigerant during heating operation in the heat pump circuit of this embodiment, and the numbers shown in the figure correspond to the parts with the same symbols in FIG. 1.

As is clear from Figure 1, the indoor side (condenser)
A first refrigerant circuit 1-3-10-12-13 and a second refrigerant circuit 2-4-10-14-15 have a common refrigerant circuit and a different outdoor side (evaporator). In addition, W ₁ and W ₂ in FIG. 2 correspond to the power required by the compressors 1 and 2, respectively.
As is clear from FIG. 2, the second refrigerant circuit requires less power per circulating amount of refrigerant than the first refrigerant circuit. Therefore, in the case of a high-temperature heat source, it is effective to increase the evaporation pressure (temperature) as in the case of a second refrigerant circuit. In this example, the COP in the first refrigerant circuit was approximately 4, similar to a heat pump for such a purpose, but in the second refrigerant circuit, it could be set to 11 because the compression ratio was small.

FIG. 3 is a conceptual diagram for explaining how to drive a compressor and utilize exhaust heat by the heat engine when an external combustion engine such as a Stirling engine is used as the heat engine. In the figure, 20 is an external combustion engine, 21 is the high temperature section heat exchanger, 22 is the low temperature section heat exchanger, 221
The water cooling duct is generally a cooling duct, 222
23 and 23' are the drive shafts of the compressors 1 and 2, 24 is the burner, 241 is the fuel supply pipe, 242 is the flame, and 243 is the guide for the combustion gas to the high temperature heat exchanger 21. duct, 244 is an arrow indicating the flow of combustion gas, 25 is a blower for supplying combustion air, 251 is an arrow indicating the flow of combustion air, 252 is a combustion gas after heating the high temperature part of the heat engine. A heat exchanger with combustion air, 253 is a conduit for combustion air, 151 is a refrigerant pipe placed in the cooling water flow 222 in the outdoor second heat exchanger 15, and 152 is a cooling water pipe during cooling operation. A cooling pipe 153 is a pipe connected to the cooling pipe for discharging the heat amount to the outside air using convection of a heat medium, 154 is a Finch-tube type radiator installed at approximately the same position as the outdoor heat exchanger 13, This is for releasing the heat pumped out by the pipes 152 and 153 to the outside air.
155 is a heat medium control valve that is closed during heating and opened during cooling; in this example, these pipes 152, radiator 154, and heat medium control valve 155 provide cooling means for cooling the cooling duct 221 during cooling. It is configured.

Now, let us briefly explain the operation of this embodiment.
First, in heating operation, valve 143 is closed and valve 1 is closed.
55 is closed and the heat engine 20 is started, the compressors 1 and 2 are driven. As a result, the first refrigerant circuit 1-3-10-12 with a large compression ratio
-13 and a second refrigerant circuit 2-4 with a small compression ratio.
-10-14-15, the former absorbs heat from the outside air, and the latter absorbs engine exhaust heat that is considerably higher in temperature than the heat engine, and both are released from the indoor heat exchanger 10.

Typical values for this example are that with the heat of combustion of the fossil fuel being 1 as the primary energy, the mechanical work produced by the heat engine is 0.3, so the cooling water flow 222 remains 0.7. of heat is transferred to the second heat exchanger 15 on the outdoor side. In the heat exchanger 15, the efficiency with which this is transferred to the refrigerant flowing in the tubes 151 is 0.85. Therefore, the amount of heat received by the refrigerant is 0.7 x 0.85 = 0.6. Since the COP in the refrigerant circuit in Figure 2 is 11, the compressor power required to transport the above 0.6 amount of heat is 0.6/(11-1) =
It is 0.06. On the other hand, the amount of heat taken by the first refrigerant circuit from the outside air is (0.3-0.06) x (4-1) = 0.72, so a total of 0.6 + 0.72 + 0.3 = 1.62 will be supplied indoors. . This indicates that the amount of heat required for the fuel to obtain the amount of heating 100 is 100/1.62=62. In this way, according to the present invention, heat for heating can be efficiently absorbed from both the heat of the outside air and the exhaust heat of the engine, so a great effect can be achieved with a small amount of fuel.

Next, cooling operation will be explained. Four-way valve 3, 4
This causes the refrigerant to flow in the direction opposite to the arrow shown in FIG. 1, and the valve 143 is closed so that the first circuit and the second circuit are operated at substantially the same compression ratio. As a result, the first and second refrigerant circuits transfer heat from indoors to outdoors under similar conditions, and exhibit a refrigerant effect. In addition, in the second heat exchanger 15 on the outdoor side, since the valve 155 is opened, the heat medium in the tube 152 heated by the flow 222 rises in the tube 153, and then passes through the radiator 154.
The air is cooled down to almost the same temperature level as the outside air, and then it descends again. In this way, engine exhaust heat and pipe 1
The heat carried from the room by the refrigerant flowing through the tube 51 is reliably released to the atmosphere by the heat radiating mechanism that combines the tube 152 and the heat radiating tube 154. It goes without saying that a pump may be installed in the middle of the pipe 153 to forcefully circulate the medium.

In the above description, an example in which an external combustion engine is used as the heat engine has been described, but the present invention is not limited to this, and it goes without saying that an internal combustion engine may also be used.
In addition, we have made it possible to recover the exhaust heat of the heat engine during heating using liquid, but this is not limited to liquid; it can be recovered by air flow, and the air flow is used for the first outdoor heat exchange. The refrigerant may be heated in the same form as the container.

As described above, the present invention includes a plurality of compressors driven by a heat engine, and during heating operation, the evaporator of the first compressor is heated by outside air, and the evaporator of the second compressor is heated by the exhaust heat of the heat engine. This is characterized in that the second compressor has a compression ratio lower than that of the first compressor, and the air conditioner has extremely high thermal efficiency.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an embodiment of the present invention, FIG. 2 is a state diagram of the refrigerant during heating operation, and FIG. 3 is a system diagram of an embodiment in which the invention is combined with an external heat engine. In the figure, 1 is a first compressor, 2 is a second compressor, 3 and 4 are four-way valves, 10 is an indoor heat exchanger (condenser), 12 is a first expansion means, and 13 is a a first outdoor heat exchanger, 14 a second expansion means, 14;
1,142 is an expansion valve, 143 is an on-off valve, 15 is a second outdoor heat exchanger, 16 is a heat engine, 20 is an external combustion engine, 21 is a high temperature section heat exchanger, 22 is a low temperature section heat exchanger, 221 is a water cooling duct, 222 is a cooling water flow,
23, 23' are drive shafts, 24 is a burner, 243 is a duct, 25 is a blower, 252 is a heat exchanger, 15
1,152 is a cooling pipe, 154 is a radiator, and 155 is a heat medium control valve. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1 an indoor heat exchanger, a first expansion means, and a first
A first refrigerant circuit that connects in series an outdoor heat exchanger, a first compressor driven by a heat engine, and a first four-way valve that controls the flow direction of refrigerant during heating and cooling. , the indoor heat exchanger, a second expansion means having a pressure control function, and a second expansion means that functions as an evaporator using the exhaust heat of the heat engine as a heat source during heating and as a condenser during cooling. an outdoor heat exchanger, and a second heat exchanger driven by the heat engine.
The second outdoor exchanger has a second refrigerant circuit that connects in series a compressor and a second four-way valve that controls the flow direction of the refrigerant during heating and cooling, and the second outdoor exchanger is connected to the heat engine. located in the cooling duct of the second
A refrigerant pipe connects the compressor and the second expansion means, and a cooling means cools the cooling duct during cooling, and the pressure control function reduces the resistance of the second expansion means during heating. At the same time, during cooling, the resistance of the second expansion means is increased to increase the expansion pressure, and the compression ratio of the second compressor is lower than the compression ratio of the first compressor. A heat pump heating/cooling system that controls both compression ratios equally.