JPH02178571A - heat pump system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a heat pump system that has a function of drying clothes, for example, in addition to indoor heating and cooling, and can be used efficiently for multiple purposes. .

(Prior art) As a conventional example of the heat pump system as described above,
For example, the apparatus described in Japanese Patent Application Laid-Open No. 63-226568 can be mentioned. The device connects a first gas pipe whose tip is branched into a plurality of gas branch pipes to one switching port of a four-way switching valve to which a discharge pipe and a suction pipe of a compressor are connected; A second gas pipe, an outdoor heat exchanger, and a liquid pipe are sequentially connected to the other switching port of the valve, and the ends of the liquid pipes are branched into a plurality of liquid receiving pipes each having an electric expansion valve interposed therein to connect the outdoor unit. The indoor heat exchanger of the indoor unit and the drying heat exchanger of the drying unit are connected in parallel between the plurality of pairs of gas branch pipes and liquid receiving pipes to form a refrigerant circulation circuit. It consists of

In the above device, the cooling operation is performed in which the refrigerant discharged from the compressor is circulated from the outdoor heat exchanger to the indoor heat exchanger, and the refrigerant discharged from the compressor is circulated from the drying heat exchanger to the outdoor heat exchanger. If there is a request for each operation that causes so-called mode conflict with the drying operation at the same time, the cooling operation is given priority. Also, during drying operation, a part of the refrigerant discharged from the compressor also flows into the indoor heat exchanger connected in parallel to the drying heat exchanger, but at this time, the liquid accumulates in the indoor heat exchanger. To prevent this, the electric expansion valve of the liquid receiving pipe connected to the indoor heat exchanger is set to a slight opening that allows the flow of refrigerant in an amount commensurate with natural heat radiation even when the indoor fan is stopped. In this way, the operation of the indoor unit is stopped.

(Problem to be Solved by the Invention) By the way, when the cooling operation and the drying operation are requested at the same time as described above, the drying operation is performed during the indoor thermo-OFF period when the temperature in the cooling room has decreased to the set temperature due to the cooling operation. The cooling operation and drying operation are repeated. In this case, during cooling operation, the indoor heat exchanger that acts as an evaporator is at a low temperature, while during drying operation, the indoor heat exchanger is supplied with high temperature and high pressure discharged refrigerant from the compressor as described above. As a result, the temperature of the indoor heat exchanger changes to a high temperature. In this way, changing the operating mode between cooling operation and drying operation causes high and low temperature changes in the indoor heat exchanger, causing problems such as dew formation on the indoor unit and its surroundings, and causing problems for users. This is something that makes people feel uncomfortable.

The present invention has been made in view of the above, and an object thereof is to provide a heat pump system that can improve air conditioning comfort by eliminating the discomfort associated with changing operating modes.

(Means for Solving the Problems) Therefore, in the heat pump system of the present invention, as shown in FIG. A first gas pipe 9 whose tip is branched into an air conditioning room side gas pipe 27 and a heating side gas pipe 28 is connected to one switching port of the four-way switching valve 4, while the other switching port of the four-way switching valve 4 is connected. a second gas pipe 10,
The outdoor heat exchanger 12 and the liquid pipe 17 are sequentially connected, and the tip of the liquid pipe 17 is branched into an air conditioning room side liquid pipe 18 and a heating side liquid pipe 19, each having a flow rate control valve 24 interposed therein. An indoor heat exchanger 36 is installed between the room side gas pipe 27 and the air conditioning room side liquid pipe 18, and an indoor heat exchanger 36 is installed between the heating side gas pipe 28 and the heating side liquid pipe 1.
This is a heat pump system in which a heating heat exchanger 37 is connected between the air conditioning chamber side gas pipe 27 and a refrigerant circulation circuit to form a refrigerant circulation circuit. Operation mode storage means 8 for storing
8, when switching to the heating operation in which the refrigerant is circulated from the heating heat exchanger 37 to the outdoor heat exchanger 12, the previous operation mode stored in the operation mode record f, α means 88 is selected. is from the outdoor heat exchanger 12 to the indoor heat exchanger 3.
In the case of cooling operation in which the refrigerant is circulated to the indoor heat exchanger 12, the on-off valve 33 is closed to start the heating operation, while the previous operation mode is to switch the refrigerant from the indoor heat exchanger 36 to the outdoor heat exchanger 12. In the case of a heating operation in which the refrigerant is circulated between the heating operation and the heating operation, an operation control means 71 is provided which continues the opening state of the on-off valve 33 and performs the heating operation.

(Function) In the heat pump system having the above configuration, when a heating operation is performed after a cooling operation in which the indoor heat exchanger 36 reaches a low temperature state, this heating operation is performed with the 15M closing valve 33 in a closed state. Therefore, the refrigerant discharged from the compressor 1 is shut off by the on-off valve 33 and is not supplied to the indoor heat exchanger 36, but is supplied only to the heating heat exchanger 37, forming a refrigerant circulation cycle. As a result, during this heating operation period, the indoor heat exchanger 36 does not change to a high temperature state, so when the cooling operation and heating operation are repeated, the temperature change of the indoor heat exchanger 36 is reduced. suppressed,
It is possible to switch the operating mode without causing dew to occur on the indoor unit or its surroundings, and it is also possible to blow out cold air more quickly when switching to cooling mode. Further, in the above, the heating operation after the heating operation is performed by opening the on-off valve 33, and in this case, the flow control valve 24 interposed in the air conditioning room side liquid pipe 18 is opened slightly. The temperature state of the indoor heat exchanger 36 and The pressure state is maintained at the same level as during heating operation, and therefore, when switching between heating operation and heating operation, operation in the change mode can be started immediately without equalizing the pressure in the refrigerant piping path. As a result, the time during which the operation is stopped 1υ1 is reduced, and hot air can be blown out more quickly when switching between heating operations.

(Example) Next, a specific example of the heat pump system of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a refrigerant circuit diagram of a heat pump system according to an embodiment of the present invention. In the figure, X is an outdoor unit, and three indoor units 1-A-C, a drying unit 11 as an example of a heating unit, and a hot water supply unit Y are connected to this outdoor unit X. .

The outdoor unit +-X has a compressor a1, and the discharge pipe 2 and suction pipe 3 of this compressor 1 are each connected to a four-way switching valve 4. The compressor 1 has an inverter 5 for controlling its rotational speed, that is, its compression capacity, and the discharge pipe 2 has a first solenoid valve 6, and the suction pipe 3 has a first and a second solenoid valve. An accumulator 7.8 is provided in each case.

A first gas pipe 9 is connected to one switching port of the four-way switching valve 4.
However, a second gas pipe 10 is connected to the other switching port. The second gas pipe 10 has an outdoor fan ■
1 attached to the outdoor heat exchanger 12 is further connected to the outdoor heat exchanger 12, and a dryer filter 13 is sequentially connected to the outdoor heat exchanger 12.
, first electric expansion valve 14, liquid receiver 15, first liquid closing valve 16
A liquid pipe 17 is connected thereto. This liquid pipe 17
The tip is branched into an air conditioning room side liquid pipe 18 and a heating side liquid pipe 19.
and three liquid branch pipes 21, 22, and 23 are connected to this method. Second electric expansion valves (flow rate control valves) 24 are interposed in these liquid branch pipes 21 to 23 and the heating side liquid pipe 19, respectively. A solenoid valve 25 is provided.

On the other hand, a first gas shutoff valve 26 is interposed in the first gas pipe 9, and its tip is empty.
7 and a heating side gas pipe 28, and a gas side header 29 is further connected to the air conditioning room side gas pipe 27, and three gas branch pipes 30, 31 are connected to this gas side header 29.
, 32 are connected.

A third solenoid valve (opening/closing valve) 33 is interposed in the air conditioning room side gas pipe 27, and in parallel with this third solenoid valve 33, it runs from the gas side header 29 side to the first gas pipe 9. A check valve 34 is connected to allow the refrigerant to flow in both directions. Incidentally, mufflers 35, . . . 35 are interposed in each of the gas branch pipes 30 to 32 and heating (Ill gas pipe 28).

and the three pairs of liquid branch pipes 21 to 23 and gas branch pipes 30 to 3.
The indoor heat exchangers 36 and 36 of the indoor units A to C installed in rooms A, B, and C, respectively, are connected between the heating side liquid pipe 19 and the heating side gas pipe 28. A drying heat exchanger (heating heat exchanger) 37 in the drying unit H is connected between the two to form a refrigerant circulation circuit.

The drying unit is installed, for example, on the ceiling of a bathroom or a changing room adjacent to a bathroom, and blows out hot air through the drying heat exchanger 37, and the drying unit By hanging clothes, the bathroom or changing room, which is normally unused except for bathing, can be turned into a drying room for drying wet clothes after washing, making effective use of the living space. It has been done in a way that is achievable.

Note that indoor fans 38, . . . , 38 are attached to each of the indoor heat exchangers 36 and the drying heat exchanger 37, respectively.

On the other hand, a gas pipe 41 for hot water supply is further connected to the discharge pipe 2 of the compressor 1, and a liquid pipe 42 for hot water supply is connected to the liquid receiver 15. A hot water supply heat exchanger 43 in the hot water supply unit Y is connected between the hot water supply unit Y and the hot water supply heat exchanger 43 . This hot water supply heat exchanger 43 is disposed at the bottom side of the hot water storage tank 44, and is configured to heat the hot water in the hot water storage tank 44 by the condensation heat of the a condensing refrigerant in this hot water supply heat exchanger 43. being done.

Note that a fourth electromagnetic valve 45 and a second gas shutoff valve 46 are sequentially installed in the hot water supply gas pipe 41, and a second liquid shutoff valve 47 is connected to the hot water supply liquid pipe 42. Further, a capillary tube 48 and a reverse valve 49 are provided.
A series-parallel circuit consisting of a capillary tube 50 and a fifth electromagnetic valve 51 is interposed. During the hot water heating operation to be described later, the check valve 49 side becomes the refrigerant flow path, and on the other hand, when the defrost operation to remove frost adhering to the outdoor heat exchanger 12 is performed by utilizing the hot water in the hot water storage tank 44, ,
The fifth solenoid valve 5I is opened and the capillary tube 5 is opened.
The refrigerant is supposed to flow through the 0.

Note that in the above device, the first and second bypass pipes 52 and 53 directly return a part of the liquid refrigerant in the liquid receiver 15 to the second accumulator 8 and the suction pipe 3, respectively.
is provided. A capillary tube 54 is interposed in the first bypass pipe 52, and the temperature of the refrigerant that has evaporated while flowing through the capillary tube 54 is detected as a saturation temperature corresponding to the evaporation pressure. Further, a sixth solenoid valve 55 and a capillary tube 56 are interposed in the second bypass pipe 53, and when the sixth solenoid valve 55 is opened, a portion of the liquid refrigerant from the liquid receiver 15 is directly compressed. By returning the flow to the suction side of the compressor 1, overheating of the compressor 1 is prevented.

In addition, in the above device, as described later, the outdoor heat exchanger 12, the indoor heat exchangers 36, 36, and the drying heat exchanger 3
Indoor air conditioning operation and drying operation are performed by circulating refrigerant between
2 and the hot water supply heat exchanger 43, the indoor heat exchange R1536/36 and the drying heat exchanger 37,
During simultaneous cooling and hot water heating operation using the indoor heat exchangers 36 and 36 and the hot water supply heat exchanger 27, the outdoor heat exchanger 1
2 are in a rest state, but in order to prevent a liquid pool from forming in each heat exchanger in these rest states,
Piping is provided that communicates the heat exchanger with the suction side of the compressor 1 when the heat exchanger is inactive. That is, the second gas pipe 10
by the third bypass pipe 59 in which the seventh solenoid valve 57 and the reverse valve 58 are interposed, and the first gas pipe 9 by the eighth solenoid valve 60
, the hot water supply gas pipe 41 is connected to the suction pipe 3 by a fourth bypass pipe 63 in which a capillary tube 6L muffler 62 is interposed, and a fifth bypass pipe 65 in which a ninth electromagnetic valve 64 is interposed. . In addition, in the figure, 66
. . 66 indicates filters installed in each of the liquid receiving pipes 21 to 23, the heating side liquid pipe 19, and the connecting pipes 17, 17, and 42 to the liquid receiving vessel 15, respectively.

Next, in the heat pump system having the above configuration, the refrigerant WJ ring cycle during heating and air conditioning operation will be described first.

In this operation, the four-way switching valve 4 is located at the switching position shown by the broken line in the figure, the first, second, and third solenoid valves 6, 25, and 33 are opened, and the other solenoid valves are closed. drive. At this time, the refrigerant discharged from the compressor 1 is supplied from the first gas pipe 9 to each indoor heat exchanger 36, and is condensed in each of these indoor heat exchangers 36. The condensed refrigerant then flows through the liquid pipe 17 to the outdoor heat exchanger 12.
The gas is evaporated and returned to the compressor 1 from the second gas pipe IO through the suction pipe 3. In this case, the degree of superheating of the evaporative refrigerant is controlled by the first electric expansion valve 14, and each second electric expansion valve 24.
24, the amount of refrigerant distributed to each of the indoor heat exchangers 36 is controlled by controlling the opening so that the temperature of the condensed refrigerant at the outlet of each of the indoor heat exchangers 36 is the same.

During operation in this heating cycle, by performing the same opening control first σ on the second electric expansion valve 24 installed in the heating side liquid pipe 19, the drying heat exchanger 37 is also The refrigerant discharged from the compressor 1 flows in a divided manner, thereby making it possible to perform heating and drying operations simultaneously.

The second electric expansion valve 24 corresponding to the indoor unit in the room where the heating is stopped during operation in the above-mentioned heating cycle and the drying unit I-H that is stopped is set to a predetermined stop opening degree (inside the heat exchanger that is stopped). In order to prevent liquid from pooling or returning to the compressor, maintain the opening at a level that allows a small amount of refrigerant to flow, commensurate with natural heat dissipation. In addition, the heating cycle described above is performed only for the drying unit H, and each indoor unit I-
By stopping the second electric expansion valves 24, 24 corresponding to A to C at 118 degrees, the drying independent operation is performed. At this time, the third solenoid valve 3
The opening/closing control 711 of No. 3 is also performed, the details of which will be explained later.

On the other hand, the cooling operation is performed by switching the four-way switching valve 4 to the switching position shown by the solid line in the figure as described above, and closing the third solenoid valve 33 to operate the compression [1]. At this time, the refrigerant discharged from the compressor 1 is circulated from the outdoor heat exchanger 12 to each indoor heat exchanger 36, and the refrigerant evaporated in each indoor heat exchanger 36 passes through the check valve 34 in the air conditioning room side gas pipe 27. It is returned to the compressor l. In this case, the first electric expansion valve 14 is fully opened, and the degree of superheat of the refrigerant is controlled by each of the second electric expansion valves 24. Note that the second electric expansion valve 24 corresponding to the indoor unit in the room where cooling is stopped is fully closed. Further, during operation in this cooling cycle, the second electric expansion valve 24 interposed in the heating side liquid pipe 19 is also fully opened to maintain the drying operation stopped state.

In the hot water heating operation, the compressor 1 is operated with the four-way switching valve 4 in the switching position shown by the broken line in the figure, the fourth solenoid valve 45 opened, and the other solenoid valves closed. As a result, the refrigerant passes through the hot water supply gas pipe 41 and is condensed in the hot water supply heat exchanger 43, and then the hot water supply liquid pipe 42, the liquid pipe 17, and the outdoor heat exchanger 12.
, and is returned to the compressor 1 via the four-way switching valve 4. In this case, each of the second electric expansion valves 24 . . . 24 is fully closed, and the first electric expansion valve 14 controls the degree of superheating of the evaporative refrigerant. Furthermore, by opening the first electromagnetic valve 6 so that the refrigerant circulation of the heating cycle occurs at the same time, hot water heating and heating or drying can be performed simultaneously. In addition, in the above, the simultaneous operation of cooling and hot water heating, that is, the operation of heating the hot water in the hot water storage tank 44 with the cooling exhaust heat, is performed by closing the first electromagnetic valve 6, opening the fourth electromagnetic valve 45, and opening the fourth electromagnetic valve 45.
The electric expansion valve 14 is fully opened, and the refrigerant discharged from the compressor 1 is condensed in the hot water supply heat exchanger 43 via the hot water supply gas pipe 41, and then the hot water supply liquid pipe 42, the liquid receiver 15, and the liquid tube 1
It is also possible to evaporate the gas in each of the indoor heat exchangers 36 and 36 via the gas pipe 7, and then return the gas to the compressor 1 via the first gas pipe 9 and the four-way switching valve 4. In this case, the degree of superheating of the evaporative refrigerant is controlled in each of the second electric expansion valves 24, 24.

Each of the above-mentioned operations has a control configuration in which each indoor temperature and the hot water temperature in the hot water storage tank 44 are detected, and the detected temperatures approach the set temperature.
In the following, switching control of the operation modes, mainly indoor cooling/heating air conditioning operation and drying operation, will be explained in more detail.

FIG. 3 shows an operation control system diagram of the heat pump system. As shown in the figure, in the above device, an outdoor control device (operation control means) 71 is installed in the outdoor unit +-X, and an indoor control device 72 is installed in each of the indoor units A to C (only the indoor unit A is shown). The drying unit H is provided with a drying operation control device 73, and the hot water supply unit Y is provided with a hot water supply control device 74. Each of the indoor control devices 72 includes a cooling/heating changeover switch 75, an operation switch 76, and an air conditioning desired room temperature control device. A temperature setting switch 77 for setting and a room temperature sensor 78 for detecting room temperature are connected to each other. Each indoor control device 72 sends a heating signal to the outdoor control device 71 according to the switching position of the cooling/heating changeover switch 75 when the operation switch 76 is ON and the detected room temperature has not reached the set room temperature. An operation request signal (hereinafter abbreviated as heating request) or a cooling operation request signal (hereinafter abbreviated as cooling request) is output. The drying operation control device 73 also includes an operation switch 79 and a temperature setting switch 80 for setting the drying room temperature.
and a temperature sensor 81 that detects the temperature in the drying room are connected to each other, and when the operation switch 79 is ON and the temperature detected by the temperature sensor 81 has not reached the set temperature, the drying operation control device A drying operation request signal (hereinafter abbreviated as drying request) is sent from 73 to the outdoor control device 71.
is output. Similarly, the hot water supply control device 74 includes an operation switch 82, a hot water temperature setting switch 83, and a hot water storage tank 4.
A hot water temperature sensor 84 that detects the hot water temperature in the hot water is connected, and when the operation switch 82 is ON and the detected hot water temperature has not reached the set hot water temperature, a hot water heating operation request signal (hereinafter referred to as hot water request) is sent. ) is output from the hot water supply control device 74 to the outdoor control device 71.

On the other hand, the outdoor control device 71 includes an operation mode determining section 8.
5, a compressor operation control section 86, and a valve control section 87, and each operation request signal is sent to the operation mode determination section 8.
5 is input. In this operation mode determining section 85, each time a change occurs in the input state of each of the operation request signals, the operation mode after the change is specified, and the specified operation mode signal and operation mode change signal, as well as the cooling request and When heating requests are being generated, unit signals corresponding to the indoor units generating those request signals are output to the pressure 1+1 machine operation control section 86 and valve control section 87.

For example, when only the drying request from the drying unit H is input, and therefore the above-described drying operation is being performed, a new cooling request is input from any of the indoor units A to C, and the drying request and the cooling request are input. If the situation changes to simultaneous manual operation, drying operation and cooling operation will cause so-called mode butting, so in this case, priority is given to cooling operation, and therefore the operation mode determined above is The section 85 outputs an operation mode signal indicating that the next operation to be performed is cooling. As a result, the valve control unit 87 first controls the opening and closing of each valve to change the refrigerant circulation path for drying operation to the circulation path for cooling operation.
Pressure again? For each compressor 1, the compressor operation control section 86 changes the compression capacity according to the load of the user unit 1-A-C after the mode change, and switches from drying operation to cooling operation. .

When the above-mentioned cooling operation continues and the indoor temperature reaches the set temperature, the cooling request is stopped and the switch to drying operation is made again. During this drying operation, the indoor temperature exceeds the set temperature and the cooling is requested again. is output and switching to cooling operation is performed. Conventionally, in such a repeated operation state of cooling and drying, problems such as frost formation occur in the indoor unit which causes high and low temperature changes as described above. Therefore, in the apparatus of the above embodiment, the third solenoid valve 33 is interposed in the air-conditioned room side gas pipe 27, and an operation mode storage section (operation mode storage means) 88 for storing the operation mode is provided in the outdoor control device 71. When the operation mode is changed as described above, the valve control section 87 controls the opening and closing of the third solenoid valve 33 based on the contents stored in the operation mode storage section 88. Regarding the opening/closing control of the third solenoid valve 33 performed by the valve control unit 87,
This will be explained based on the control flowchart shown in FIG.

The outdoor unit x is connected to an indoor unit instead of the drying unit H so that it can be configured as a device for air conditioning operation in four rooms.
On the side, even when the drying unit H is connected as described above, this drying unit H is handled as an indoor unit installed in the D room. In other words, the drying request issued by the drying unit H is processed as a heating request from room D, which has a lower priority than the operation request from each indoor unit A to C installed in rooms A to C. ing. Further, in the flowchart of FIG. 4, the simultaneous cooling/hot water supply operation mode and the simultaneous heating/hot water supply operation mode will be described as being included in the cooling operation mode and the heating operation mode, respectively.

Step S1 in FIG. 4 is a step for determining whether or not there is an operation mode change signal that is output when there is a change in the input state of each operation request signal to the operation mode determining section 85. When is output, the process moves from step S1 to step S2, and it is first determined whether or not the operation mode signal output at the same time as the operation mode change signal is the cooling operation mode. In the case of cooling, the third electromagnetic valve 33 is closed in step S3, and then the process returns to step S1 to continue waiting for input of a new operation mode change signal. Therefore, in the cooling operation, as described above, the third solenoid valve 33
This is done by keeping the valve closed.

On the other hand, in step S2, if the operation mode signal is not cooling, the process moves to step S4, and it is determined whether the operation mode signal is heating. If it is heating, then in step S5, the indoor unit generating the heating request is determined based on the unit signal output from the operation mode determination section 85 together with the operation mode signal, and this is the indoor unit of room D. In other words, if there is only drying unit 1, the process moves to step S6.

In this step S6, the operation mode storage section 8
It is determined whether the previous operation mode stored in step 8 was cooling operation. If the cooling operation is in progress, the third on-off valve 33 is closed in step S3 and the process returns to step S1.On the other hand, if the previous operation was not in the cooling operation, a heating request is made in step S5. is from indoor unit A-C other than drying unit 1-H, or from indoor unit 1-A together with drying unit l-11.
-C is also output, the third electromagnetic valve 33 is opened in step S7, and the process returns to step S1.

As a result of the above control, when the drying operation is performed after the cooling operation, this drying operation is performed with the third on-off valve 33 closed, and also when the cooling operation is performed after the drying operation, the third on-off valve 33 is closed. The solenoid valve is maintained in a closed state. Therefore, the low temperature state of the indoor heat exchanger 36, which acts as an evaporator during cooling operation, is maintained even when switching to drying operation afterwards, the refrigerant discharged from the compressor 1 is cut off by the on-off valve 33, and the indoor heat exchanger 36 is kept in a low temperature state. It is not supplied to the container 36, and the temperature is maintained at a substantially low temperature without changing to a high temperature even during the drying operation period. As a result, when cooling operation and drying operation are repeated, high and low temperature changes in the indoor heat exchanger 36 can be suppressed, so operation can be performed without causing dew generation on the indoor unit or its surroundings, which was conventional. Operation can be continued while switching modes. Also, when switching from drying operation to cooling operation, the previous indoor heat exchanger 3
6 is maintained at a low temperature, the cold air is blown out more quickly.

On the other hand, when the indoor heating operation is performed intermittently in accordance with 0N10FF of the indoor thermostat along with the drying operation, and therefore the simultaneous heating/drying operation and the drying alone operation are repeated, the third solenoid valve 33 is maintained in the open state by the above control. As a result, during the drying standalone operation period, a small amount of high-temperature, high-pressure refrigerant flows also into the stopped indoor heat exchanger 36 in accordance with the opening degree of the second dynamic expansion valve having the stopped opening degree. In this case, the indoor heat exchanger 36 is maintained at a high temperature. As a result, hot air is blown out more quickly even when switching from drying only operation to heating operation.

In addition, in step S4 of FIG. 4, if the operation mode signal is not heating, the process moves to step S8, and it is determined whether or not it is the hot water supply only operation, and if it is the hot water supply only operation, then in step S9, the current mode is determined. It is determined whether the third solenoid valve 33 is open or closed, and if it is in the open state, step S
7, and if the valve is closed, step S3
, respectively, to maintain the opened and closed states before and after changing the operating mode. In addition, in step S8, if the hot water supply operation is not independent, that is, if all the operation request signals are stopped and the operation is stopped, the third solenoid valve 33 is closed in step S3, and the process returns to step S1. conduct.

By the way, before and after switching the operation mode, if the high and low pressure conditions in the refrigerant piping path, especially the high and low pressure conditions in the indoor heat exchanger 36, are reversed, compression III is temporarily stopped and the high and low pressures are equalized. It is necessary to perform pressure equalization processing such as waiting for the new operation mode to control the opening and closing of each valve in response to the new operation mode, and restarting the compressor 1. If operation is started in a new operation mode without performing such pressure equalization processing, an impactful pressure equalization noise will be generated, which will propagate into the room and cause abnormal noise and vibration, which may harm the user. This is because it causes discomfort.

Therefore, in the outdoor control device 71, as shown in FIG. 3, a new operation mode signal from the operation mode determining section 85 and operation mode information 1. A pressure equalization processing control section 89 is provided which compares the previous operation mode in the α section 88 and outputs a pressure equalization command as described above. This pressure equalization processing control section 89
The command to stop and restart the compressor JR,1 as described above is output to the compressor operation control section 86, and after the operation of the compressor 1 is stopped, the first and second electric expansion valves are outputted to the valve control section 87. 14.
24 gradually opens the seventh solenoid valve 57 when the pressure is equalized after operation in the cooling cycle, and the eighth solenoid valve 60 when the pressure is equalized after the operation in the heating cycle.
Valve opening commands, etc. are output.

FIG. 5 shows a control flowchart in the pressure equalization processing control section 89 that determines whether or not to perform pressure equalization processing at the time of switching the operating mode in the operation mode change in the heating cycle. In the above device, since the heating and subsequent drying operations are performed with both the third solenoid valve 33 open, the high-pressure refrigerant flows through the indoor heat exchanger 36 before and after switching, as described above. The refrigerant circulation path at other locations is also maintained at a similar pressure state, so when switching from heating operation to drying operation alone, or from drying operation to heating operation,
It is possible to immediately start operation in a new operation mode without performing the pressure equalization process as described above. Therefore, as shown in FIG. 5, when the operation mode determining section 85 generates an operation mode change signal (step 5ll),
Only when the previous operation was an independent heating operation for room D, that is, an independent drying operation (step S12), and this independent drying operation was performed with the third solenoid valve 33 closed (step S13). In step 514, it is confirmed that the compressor l is in operation, and in step S15, the pressure equalization processing command as described above is output. Then, in step S16, a pressure equalization processing end signal is output, and operation in a new operation mode is started.

As a result of the above control, in the intermediate seasons of spring and autumn when heating and cooling operation requests may occur at the same time, cooling operation is performed first, followed by drying-only operation, heating operation, or simultaneous heating and drying operation. Pressure equalization is performed at the time of infrequent operation mode switching, and when switching between drying-only operation and operation mode in winter when heating operation is required for each indoor unit, the above-mentioned equalization process is performed. Operation in a new operation mode is started immediately without pressure treatment.

Therefore, when switching the operating mode in the heating cycle, there is usually no shutdown period required for pressure equalization, and
Therefore, operational efficiency is improved, and from this point of view, the device is capable of improving air conditioning comfort.

In the above embodiment, an example was explained in which the drying unit 1-11 having the drying heat exchanger 37 was provided as a heating unit. It is also possible to provide a configuration in which other heating units are provided.

(Effects of the Invention) As described above, in the heat pump system of the present invention, when cooling operation and heating operation are repeated, the operation can be switched in such a way that changes in high and low temperatures of the indoor heat exchanger are suppressed. In addition to eliminating problems such as the formation of dew on the indoor unit and its surroundings, cold air can be blown out more quickly when switching to cooling mode, and when switching between heating mode and heating mode. This method does not require a shutdown period for pressure equalization processing, and can blow out hot air more quickly when switching to heating operation, improving air conditioning comfort.

[Brief explanation of the drawing]

Fig. 1 is a configuration and functional block diagram of the present invention, Fig. 2 is a refrigerant circuit diagram of a heat pump system according to an embodiment of the invention, Fig. 3 is an operation control system diagram of the heat pump system, and Fig. 4 is a diagram of the operation control system of the heat pump system. FIG. 5 is a flowchart of the opening/closing control of the third electromagnetic valve performed by the valve control section in the system, and FIG. 5 is a control flowchart when changing the operation mode in the heating cycle performed by the pressure equalization processing control section in the heat pump system. l...Compressor, 2...Discharge piping, 3...Suction piping, 4...Four-way switching valve, 9...First gas pipe, 10...
- Second gas pipe, 12... Outdoor heat exchanger, 17... Liquid pipe, 18... Air conditioning room side liquid pipe, 19... Heating side liquid pipe,
24...Second electric expansion valve (flow rate control 211 valve), 27
...Air conditioning room side gas pipe, 28...Heating side gas pipe, 33
...Third solenoid valve (opening/closing valve), 36...Indoor heat exchanger, 37...Drying heat exchanger (heating heat exchanger), 71
. . . Outdoor control device (operation control device), 88 . . . Operation mode storage unit (operation mode storage means).

Claims (1)

[Claims] 1. Connect the discharge pipe (2) and suction pipe (3) of the compressor (1) to the four-way switching valve (4), and connect the tip of the four-way switching valve (4) to one switching port for air conditioning. Room side gas pipe (2
7) and the heating side gas pipe (28), while a second gas pipe (10) is connected to the other switching port of the four-way switching valve (4). Outdoor heat exchanger (1
2), connect the liquid pipes (17) in sequence, and connect the liquid pipes (17) in sequence.
The tips of 7) are branched into an air conditioning room side liquid pipe (18) and a heating side liquid pipe (19) each having a flow rate control valve (24) interposed therein, and are connected to the air conditioning room side gas pipe (27) and the air conditioning room side liquid pipe (19). Side liquid pipe (18)
An indoor heat exchanger (36) is connected between the heating side gas pipe (28) and the heating side liquid pipe (19), and a heating heat exchanger (37) is connected between the heating side gas pipe (28) and the heating side liquid pipe (19) to form a refrigerant circulation circuit. A heat pump system comprising: an on-off valve (33) interposed in the air conditioning room side gas pipe (27);
driving mode storage means (88) for storing the driving mode;
From the heating heat exchanger (37) to the outdoor heat exchanger (12)
When switching to heating operation where refrigerant is circulated between
When the previous operation mode stored in the operation mode storage means (88) is a cooling operation in which refrigerant is circulated from the outdoor heat exchanger (12) to the indoor heat exchanger (36), the The heating operation is started by closing the on-off valve (33), while the previous operation mode was a heating operation in which the refrigerant is circulated from the indoor heat exchanger (36) to the outdoor heat exchanger (12). In this case, an operation control means (71) that keeps the on-off valve (33) open and performs heating operation.
A heat pump system characterized by being provided with.