JP2797656B2 - Heat pump type air conditioner - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a heat pump type air conditioner, and more particularly, to a heat pump type air conditioner having a refrigerant heater for heating.

[Conventional technology]

In order to obtain an efficient heating effect in a heat pump type air conditioner using a heat medium such as hydraulic oil generated by driving a vehicle as a heat source of a refrigerant heater for heating, the present applicant has filed Japanese Patent Application No. Hei. No. 241509 (hereinafter simply referred to as the prior application) has been filed.

This is because, as shown in FIG. 6, the high-temperature and high-pressure gas refrigerant discharged from the refrigerant compressor 51 in the heating operation passes through the outdoor heat exchange 52 in which the outdoor fan 53 is stopped, and bypasses the pressure reducing device 54. After entering the indoor heat exchanger 55 to which the indoor fan 56 is blown through the on-off valve 60, the heat is radiated and condensed and liquefied. The refrigerant is heated by the refrigerant heater 58, then the gas refrigerant is led out by the accumulator 59, and circulates back to the compressor 51 (indicated by a solid arrow).

[Problems to be solved by the invention]

Meanwhile, in the prior application having the above configuration, the outdoor heat exchanger 52 is used as a pipe for the high-temperature gas refrigerant during the heating operation, so that when the heat release amount in the outdoor heat exchanger 52 is large,
Along with that, the amount of heat radiation in the indoor heat exchanger 55 decreases,
In particular, when the outside air temperature is low, the amount of heat radiated by the outdoor heat exchanger 52 is large, so that the amount of heat radiated by the indoor heat exchanger 55 is extremely reduced, and it is found that the indoor heating capacity is insufficient.

In addition, it has been found that the outdoor heat exchanger 52 does not provide an efficient heating effect because heat is radiated by natural convection even without the inflow of natural wind.

By the way, in order to solve the above-mentioned problem, it is conceivable to flow the refrigerant by bypassing the outdoor heat exchanger 52 during the heating operation. In this case, however, the refrigerant circulating in the refrigerant circuit in the heating operation stagnates and stays. As a result, there is a problem that the operation becomes insufficient and the compressor 51 is adversely affected.

The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a heat pump type air conditioner in which a sufficient heating capacity and an efficient heating effect can be obtained without refrigerant stagnation in a heating operation.

[Means for solving the problem]

In order to achieve the above object, the present invention provides: (1) a compressor that compresses and discharges a refrigerant; an indoor heat exchanger that performs heat exchange between the refrigerant and indoor air; An outdoor heat exchanger that performs heat exchange between the indoor heat exchanger and the outdoor heat exchanger,
A first decompression device that decompresses the refrigerant, a first auxiliary refrigerant circuit that is provided to bypass the first decompression device, and has a first on-off valve that selectively shuts off the flow of the refrigerant; A refrigerant switching device for switching a flow direction of the refrigerant discharged from the compressor between the indoor heat exchanger side and the outdoor heat exchanger side; and the compressor which branches off from a downstream side of the outdoor heat exchanger during heating. A second on-off valve for selectively shutting off the flow of the refrigerant, a second decompression device for decompressing the refrigerant, and a second auxiliary refrigerant device having a refrigerant heater for heating the refrigerant. A check valve disposed in a refrigerant pipe connecting the branch portion of the second auxiliary refrigerant circuit and the refrigerant switching device, and preventing a refrigerant from flowing into the refrigerant switching device in a heating operation; During the cooling operation, the first on-off valve and the second on-off valve are closed. In the heating operation, the first opening / closing valve and the second opening / closing valve are opened using technical means. (2) The indoor fan that blows air to the indoor heat exchanger is used for cooling and heating. It is effective to operate both the operation and the outdoor fan that blows air to the outdoor heat exchanger in the cooling operation and stop in the heating operation.

[Action]

According to the above means, the liquid refrigerant condensed and liquefied in the indoor heat exchanger during the heating operation flows into the outdoor heat exchanger by bypassing the first pressure reducing device, but is converted into a gas refrigerant for the liquid refrigerant. Since the heat transfer coefficient is extremely small as compared with the above, the gas passes through the outdoor heat exchanger with a small amount of heat exchange. The passed liquid refrigerant is blocked by the check valve, flows into the second auxiliary refrigerant circuit, is decompressed by the second decompression device, is heated by the refrigerant heater, becomes gas refrigerant, and returns to the compressor. Since the amount of heat exchange in the heat exchanger is extremely smaller than that of the gas refrigerant due to the liquid refrigerant as described above, the amount of heat exchange in the indoor heat exchanger required for indoor heating increases accordingly.

〔Example〕

 Hereinafter, the present invention will be described based on an embodiment shown in the drawings.

FIG. 1 is a system configuration diagram showing one embodiment of a heat pump type air conditioner of the present invention.

The configuration will be described according to the flow of the refrigerant in the heating operation. Reference numeral 1 denotes a refrigerant compressor driven by an engine or the like (not shown), and a refrigerant switching device that switches a flow direction of the refrigerant discharged from a discharge side of the compressor 1. Is connected to the indoor heat exchanger 3 via the four-way valve 2. The indoor heat exchanger 3 functions as a condenser in a heating operation and functions as an evaporator in a cooling operation.

There is a first auxiliary refrigerant circuit 21 having a first opening / closing valve 10 provided from the indoor heat exchanger 3 and bypassing a first depressurizing device 4 which is a depressurizing device for cooling. Connected to exchanger 5. The outdoor heat exchanger 5 is simply a refrigerant pipe in the heating operation, and functions as a condenser in the cooling operation.

A second branch valve, which branches off from the middle of a refrigerant pipe 23 connecting the outdoor heat exchanger 5 and the four-way valve 2, has a second on-off valve 11, a second pressure reducing device 6, and a refrigerant heater 7 using hydraulic oil as a heat medium. There is a second auxiliary refrigerant circuit 22, which is connected to the accumulator 8 via the auxiliary refrigerant circuit 22, and is connected from the accumulator 8 to the suction side of the compressor 1.

During the heating operation, the second auxiliary refrigerant circuit 22 is connected to the refrigerant pipe connecting the outdoor heat exchanger 5 and the four-way valve 2 to prevent the refrigerant from flowing from the outdoor heat exchanger 5 to the four-way valve 2. The check valve 9 is provided on the downstream side of the branching portion 22a, and the system is configured as described above.

Here, the flow of the refrigerant flows in the direction of the solid-line arrow shown in the drawing in the heating operation, and flows in the direction of the dotted line in the drawing in the cooling operation.

In the drawing, reference numeral 12 denotes an indoor fan that blows air to the indoor heat exchanger 3, and 13 denotes an outdoor fan that blows air to the outdoor heat exchanger 5.

FIG. 2 shows an electric circuit relating to a main part of the above embodiment.

In the figure, a cooling / heating switch 18 and a blower switch 19 are connected to a control circuit 20 as input switches, while a relay of the four-way valve 2 is used as a control relay.
14, relay 15 for first and second on-off valves 10 and 11, indoor fan 12
The relay 16 of the outdoor fan 13 and the relay 17 of the outdoor fan 13 are respectively connected, and an electric circuit is configured by the above.

In the heating operation, the control circuit 20 energizes the relay 15 to open the first and second on-off valves 10 and 11, and energizes the relay 16 to operate the indoor fan 12. Control. Although the relay 14 is not energized, in this case,
The four-way valve 2 is on the heating side.

On the other hand, in the cooling operation, the four-way valve 2 is switched to the cooling side by energizing the relay 14, and the indoor fan is energized by energizing the relay 16.
Control is performed so that the outdoor fan 13 is operated by energizing the relay 12 and energizing the relay 17. In this case, the relay 15 is not energized, and the first and second on-off valves 10 and 11 are closed.

Next, the operation of the heat pump air conditioner having the above configuration will be described with reference to FIG.

In the heating operation, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 is sent to the indoor heat exchanger 3 through the four-way valve 2 and radiates heat when condensed and liquefied in the indoor heat exchanger 3. The indoor fan 12 blows warm air into the room to heat the room.

The liquid refrigerant condensed and liquefied in the indoor heat exchanger 3 passes through the first auxiliary refrigerant circuit 21 via the first opening / closing valve 10 which is opened by bypassing the first pressure reducing device 4 and the outdoor heat exchanger 5 Is sent to the outdoor heat exchanger 5 because the outdoor fan 13 is stopped.
The liquid refrigerant passes with a small amount of heat exchange due to natural convection in the second sub-refrigerant circuit 22 and is then blocked by the check valve 9.
And is sent to the second decompression device 6 through the second opening / closing valve 11 which is open, and is decompressed and expanded by the second decompression device 6 to become a mist refrigerant, and enters the refrigerant heater 7. Heated and evaporated, the gas refrigerant is led out by the accumulator 8 and
Circulates back to the suction side.

Here, the outdoor heat exchanger 5 is in the high-pressure liquid line, and the liquid refrigerant passing through the outdoor heat exchanger 5 has a very small heat conductivity (about 1/30) as compared with the gas refrigerant, and the heat exchange rate is low. Since it is extremely small, the heat loss of the refrigerant in the outdoor heat exchanger 5 is small,
Accordingly, the heat exchange rate in the indoor heat exchanger 3 can be increased.

On the other hand, in the cooling operation, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 passes through the four-way valve 2 and the check valve 9. Since the on-off valve 11 is closed, the gas refrigerant is supplied to the outdoor heat exchanger 5.
, And is cooled and condensed and liquefied by the blowing of the outdoor fan 13.

The liquid refrigerant condensed and liquefied in the outdoor heat exchanger 5 is sent to the first decompression device 4 because the first on-off valve 10 in the first auxiliary refrigerant circuit 21 is closed, and is decompressed and expanded to form a mist-like refrigerant. Becomes
When entering the indoor heat exchanger 3 and evaporating, the heat is absorbed, and the indoor fan 12 sends cool air into the room to cool the room.

The refrigerant evaporated in the indoor heat exchanger 3 enters the accumulator 8 via the four-way valve 2, and the gas refrigerant is discharged to the compressor 1.
Circulates back to the suction side.

In the above operation, the energization control in the heating operation and the cooling operation will be described based on the electric circuit diagram of FIG. 2 and the operation flowchart shown in FIG.

First, in step 101, it is determined whether or not the blow switch 19 is turned on, and the blow switch 19 is not turned on (N
In the case of O), the process returns to the start. If the blower switch 19 is ON (YES), the process proceeds to step 102, where the relay 16 is energized and the indoor fan 12 operates. Then step 10
In step 3, it is determined whether or not the cooling operation is being performed.
In the case of ES), the process proceeds to step 104, where the relay 14 is energized to bring the four-way valve 2 into the cooling position, and the process proceeds to step 105, where the relay 15 is not energized and the first and second on-off valves 10 and 11 are closed. Then, the routine proceeds to step 106, where the relay 17 is energized and the outdoor fan 13 operates.

On the other hand, if the cooling operation is not performed (NO) in step 103, it is determined whether or not the heating operation is performed in step 107. If the heating operation is performed (YES), the process proceeds to step 108 and the relay 14 is energized. First, the four-way valve 2 is set to the heating position, and the routine proceeds to step 109, where the relay 15 is energized, and the first and second on-off valves 10 and 11 are opened. If the heating operation is not performed (NO) in step 107, the energization control ends.

Next, in the heat pump type air conditioner of the above configuration,
The increase in the heating capacity during the heating operation will be described with a Mollier diagram.

FIG. 4 shows a Mollier diagram during the heating operation in the configuration of the prior application, and FIG. 5 shows a Mollier diagram during the heating operation in the configuration of the present invention.

In the figure, E1 is the enthalpy of the refrigerant heat-exchanged in the indoor heat exchanger, and E2 is the enthalpy of the refrigerant heat-exchanged in the outdoor heat exchanger.

In the case of the configuration of the present invention, the total enthalpy (E1 + E2) of the refrigerant that is heat-exchanged in the indoor heat exchanger and the outdoor heat exchanger in the heating operation is equal to the total heating value, as compared with the configuration of the prior application. Does not change, but the enthalpy E1 of the refrigerant that is heat-exchanged in the indoor heat exchanger, that is, the calorific value of the indoor heat exchanger is much larger. This indicates that the indoor heating capacity of the indoor heat exchanger is much larger.

Next, in this embodiment, the working oil is used as the heat medium of the refrigerant heater 7. However, engine cooling water may be used, and waste heat generated in factories or the like can be used. In addition, the present invention can be applied to a stationary heat pump type air conditioner.

The positions of the second on-off valve 11 and the second pressure reducing device 6 provided on the upstream side of the refrigerant heater 7 may be interchanged.

Further, as the first on-off valve 10, a check valve can be used instead of the on-off valve.

Further, when the gasification of the refrigerant in the refrigerant heater 7 is sufficiently performed, the accumulator 8 is eliminated and the refrigerant heater 7
And the suction side of the compressor 1 may be directly connected.

〔The invention's effect〕

Since the present invention is configured as described above,
The following effects are obtained.

(1) In the configuration of claim 1, the amount of heat exchange in the outdoor heat exchanger during the heating operation is reduced, and the amount of heat exchange in the indoor heat exchanger is accordingly increased. The heating capacity is improved, and an efficient heating effect is obtained.

(2) In the configuration of claim 2, since the outdoor fan is stopped during the heating operation, the heat loss of the refrigerant in the outdoor heat exchanger is reduced, and the indoor heating capacity is improved.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing one embodiment of a heat pump type air conditioner of the present invention, FIG. 2 is an electric circuit diagram of a main part of the same device, FIG.
4 and 5 are Mollier diagrams for explaining the effect, and FIG.
The figure is a system configuration diagram of the heat pump type air conditioner of the prior application. 1 ... Compressor, 2 ... Four-way valve (refrigerant switching device), 3 ... Indoor heat exchanger, 4 ... First decompression device, 5 ... Outdoor heat exchanger, 6 ...
... second pressure reducing device, 7 ... refrigerant heater, 9 ... check valve, 10 ...
... first on-off valve, 11 ... second on-off valve, 12 ... indoor fan, 13 ... outdoor fan, 21 ... first auxiliary refrigerant circuit, 22 ...
... Second auxiliary refrigerant circuit.

Claims (2)

(57) [Claims] A compressor for compressing and discharging the refrigerant; an indoor heat exchanger for exchanging heat between the refrigerant and indoor air; and an outdoor heat exchanger for exchanging heat between the refrigerant and outdoor air. A first pressure reducing device disposed between the indoor heat exchanger and the outdoor heat exchanger and configured to reduce the pressure of the refrigerant; provided to bypass the first pressure reducing device to selectively flow the refrigerant; A first auxiliary refrigerant circuit having a first on-off valve that shuts off a refrigerant, a refrigerant switching device that switches a flow direction of refrigerant discharged from the compressor between the indoor heat exchanger side and the outdoor heat exchanger side, A second on-off valve that branches off from the downstream side of the outdoor heat exchanger and connects to the suction side of the compressor during heating, and a second on-off valve that selectively shuts off the flow of refrigerant; A second auxiliary refrigerant circuit having a device and a refrigerant heater for heating the refrigerant; A check valve disposed in a refrigerant pipe connecting the branch portion of the refrigerant circuit and the refrigerant switching device, for preventing a refrigerant from flowing into the refrigerant switching device in a heating operation, and the first valve in a cooling operation. And a second on-off valve and a second on-off valve are closed during the heating operation, and the first and second on-off valves are opened during the heating operation. 2. An indoor fan for blowing air to the indoor heat exchanger is operated for both cooling and heating operations, and an outdoor fan for blowing air to the outdoor heat exchanger is operated for cooling operation and stopped for heating operation. The heat pump air conditioner according to claim 1.