JP2014119145A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To speedily perform efficient air-conditioning operation by attaining a suitable refrigerant amount from the start of the air-conditioning operation.SOLUTION: An air conditioner includes a control device 20 which controls the amount of a refrigerant by controlling a high pressure-side flow control device 6 and a low pressure-side flow control device 7 when starting the operation of a compressor 1. The control device 20 makes the opening of the high pressure-side flow control device 6 larger than the opening of the low pressure-side flow control device 7 so as to reserve the refrigerant in a receiver 5 in air-conditioning operation in which a suitable refrigerant amount is small, for example, in a heating operation. In an air-conditioning operation in which the suitable refrigerant amount is large, for example, in a cooling operation, the opening of the low pressure-side flow control device 7 is made larger than the opening of the high pressure-side flow control device 6 so that the refrigerant is not reserved in the receiver 5.

Description

  The present invention relates to an air conditioner that adjusts the amount of refrigerant flowing through a refrigerant circuit using a receiver that accumulates refrigerant.

  In an air conditioner, a compressor, a four-way valve, a condenser, a throttling device, and an evaporator are sequentially connected by a pipe to form a refrigeration cycle in which refrigerant circulates. In the air conditioner described in Patent Document 1, receivers are connected in parallel from both sides of the throttle device via a high-pressure side expansion valve and a low-pressure side expansion valve, respectively. And in order to keep the refrigerant | coolant amount which circulates through a refrigerant circuit appropriately, the opening degree of a high voltage | pressure side expansion valve and a low voltage | pressure side expansion valve is controlled based on the discharge temperature and preset discharge temperature of the refrigerant | coolant discharged from a compressor. .

JP 2002-156166 A

  In the above air conditioner, the refrigerant is stored in the receiver during the air conditioning operation, and the amount of the refrigerant is adjusted. By the way, the optimum refrigerant amount varies depending on the type of air conditioning operation. The optimum refrigerant amount during the cooling operation is larger than the optimum refrigerant amount during the heating operation. When the refrigerant is accumulated in the receiver, the amount of refrigerant circulating during the cooling operation is reduced. Therefore, the refrigerant must be discharged from the receiver and returned to the refrigerant circuit. Thus, depending on the type of air conditioning operation, it is necessary not only to store the refrigerant in the receiver, but also to discharge the refrigerant from the receiver.

  Further, when the air conditioning operation is started and the compressor is operated, the refrigerant discharge temperature gradually increases. Therefore, when the opening of the high-pressure side expansion valve and the low-pressure side expansion valve is controlled according to the discharge temperature at the start of the air-conditioning operation, the opening degree of each expansion valve always changes and the amount of circulating refrigerant is adjusted appropriately. It becomes difficult. Since it takes time until the optimum amount of refrigerant is reached, the heat exchange efficiency during this period deteriorates and the power consumption also increases.

  In view of the above, the present invention provides an air conditioner that can quickly perform efficient air-conditioning operation by adjusting the amount of refrigerant circulating in the refrigerant circuit so that the optimum refrigerant amount is obtained from the start of air-conditioning operation. Objective.

  In the present invention, a compressor, a condenser, an expansion device, and an evaporator are connected by piping to form a refrigerant circuit. The refrigerant circuit is provided with a receiver for accumulating refrigerant, and the receiver includes a high-pressure side flow control device and a low-pressure side. The high-pressure side flow control device and the low-pressure device are connected to the refrigerant circuit via the flow rate adjusting device when starting the compressor operation so that the refrigerant circulating in the refrigerant circuit has an optimum refrigerant amount corresponding to the type of air conditioning operation. A control device for adjusting the refrigerant amount by controlling the side flow rate adjusting device is provided.

  The optimum amount of refrigerant varies depending on the type of air conditioning operation. The operation of the compressor is started in accordance with the start of the air conditioning operation. Therefore, by controlling the high pressure side flow rate adjustment device and the low pressure side flow rate adjustment device immediately before the start of the air-conditioning operation, the refrigerant is stored in the receiver or the refrigerant from the receiver as the compressor starts operating. The refrigerant is discharged into the circuit. Therefore, it is possible to set the optimum refrigerant amount according to the type of the air conditioning operation from the start of the air conditioning operation.

  The control device is configured so that the amount of refrigerant passing through the high-pressure side flow control device is larger than the amount of refrigerant passing through the low-pressure flow control device so that the refrigerant is accumulated in the receiver during air-conditioning operation with a small amount of optimal refrigerant. The flow rate adjusting device and the low pressure side flow rate adjusting device are operated. During air conditioning operation with a large amount of optimal refrigerant, the high-pressure flow rate adjustment device is such that the amount of refrigerant passing through the high-pressure side flow rate adjustment device is smaller than the refrigerant amount passing through the low-pressure side flow rate adjustment device so that the refrigerant does not accumulate in the receiver. And the low-pressure side flow control device is operated.

  That is, when the optimum refrigerant amount during the cooling operation is larger than the optimum refrigerant amount during the heating operation, the control device prevents the refrigerant from accumulating in the receiver when starting the cooling operation. Open and close the high-pressure flow control device. When starting the heating operation, the high pressure side flow rate adjustment device is opened and the low pressure side flow rate adjustment device is closed in order to store the refrigerant in the receiver. Here, when the high pressure side flow rate adjustment device and the low pressure side flow rate adjustment device are devices of the same type, the amount of refrigerant passing therethrough is determined in proportion to the opening degree. When the air conditioning operation is performed with a small amount of the optimum refrigerant, the control device makes the opening degree of the high pressure side flow rate adjustment device larger than the opening degree of the low pressure side flow rate adjustment device. During the air conditioning operation with a large amount of optimum refrigerant, the control device makes the opening degree of the low pressure side flow rate adjustment device larger than the opening degree of the high pressure side flow rate adjustment device.

  A room temperature sensor for detecting the room temperature is provided, and the control device determines the type of the air conditioning operation based on the room temperature. When the room temperature is high, it is determined that the air-conditioning operation has a large amount of optimum refrigerant, and when the room temperature is low, it is determined that the air-conditioning operation has a small amount of optimum refrigerant. Thereby, it can be discriminate | determined whether the air conditioning operation to start is a cooling operation or a heating operation. Further, when the automatic operation is started, the cooling operation or the heating operation is performed based on the room temperature and the set temperature, and it is possible to determine which operation is started and to set the optimum refrigerant amount according to the operation. be able to.

  The control device controls the high-pressure side flow rate adjustment device and the low-pressure side flow rate adjustment device when the operation of the compressor is started when the thermostat is off. When the room temperature reaches the set temperature, the thermo-off is performed and the compressor is stopped. When a temperature difference occurs between room temperature and the set temperature after a while, the operation of the compressor is resumed. At the start of the operation of the compressor, the control device determines whether the amount of refrigerant passing through one of the high-pressure side flow control device and the low-pressure side flow control device is the other flow control device, depending on the type of air conditioning operation. The high-pressure side flow rate adjustment device and the low-pressure side flow rate adjustment device are operated so as to be larger than the refrigerant amount passing through. For example, according to the type of the air conditioning operation, the control device increases the opening degree of one of the high pressure side flow rate adjusting device and the low pressure side flow rate adjusting device to be larger than the opening degree of the other flow rate adjusting device.

  The control device adjusts the high-pressure flow rate so that the amount of refrigerant passing through the high-pressure flow rate adjusting device and the low-pressure flow rate adjusting device changes when the rotation speed before stopping the compressor is different from the rotation speed at the start of operation. The apparatus and the low-pressure side flow control device are operated. The optimum amount of refrigerant varies depending on the rotational speed of the compressor. Therefore, when the number of revolutions at the start of operation increases from the number of revolutions before the operation is stopped, the amount of refrigerant passing through the high-pressure side flow control device passes through the low-pressure side flow control device as the optimum refrigerant amount increases. The amount of refrigerant passing through each flow rate adjusting device is adjusted so as to be smaller than the amount of refrigerant. For example, the opening degree of the high pressure side flow control device is made smaller than the opening degree of the low pressure side flow control device. When the number of revolutions at the start of operation falls below the number of revolutions before the stop of operation, the amount of refrigerant that passes through the high-pressure side flow controller is reduced as the optimum amount of refrigerant decreases. Each flow rate adjusting device is adjusted to increase the flow rate. For example, the opening degree of the high-pressure side flow control device is made larger than the opening degree of the low-pressure side flow control device.

  In the control device, the amount of refrigerant passing through the high pressure side flow rate adjusting device and the low pressure side flow rate adjusting device at the start of operation of the compressor is the same as the amount of refrigerant passing through each flow rate adjusting device before the compressor is stopped. As described above, the high pressure side flow rate adjusting device and the low pressure side flow rate adjusting device are operated. That is, when the number of revolutions before the stop of the compressor is the same as the number of revolutions at the start of the operation, the optimum amount of refrigerant before and after the compressor stops does not change, so the amount of refrigerant that passes through each flow control device before and after the stop changes. Absent. For example, the control device does not change the opening degree of the high pressure side flow rate adjustment device and the low pressure side flow rate adjustment device. In this case, since the optimum refrigerant amount does not change, the opening degree of each flow rate adjusting device may be left as it is.

  An outside air temperature sensor for detecting the outside air temperature is provided, and the control device changes the rotation speed of the compressor according to the outside air temperature, and passes through the high pressure side flow rate adjustment device and the low pressure side flow rate adjustment device according to the change in the rotation speed. Change the amount of refrigerant. When the outside air temperature rises during the cooling operation, the rotation speed of the compressor increases and the optimum refrigerant amount increases. When the outside air temperature decreases, the rotation speed of the compressor decreases and the optimum refrigerant amount decreases. In this way, the amount of refrigerant passing through each flow rate adjusting device is adjusted so that the amount of refrigerant circulating circulates in accordance with the increase or decrease in the optimum amount of refrigerant according to the change in the outside air temperature.

  According to the present invention, it is possible to start the air-conditioning operation and quickly obtain the optimum refrigerant amount according to the type of the air-conditioning operation. Thereby, after starting an air-conditioning driving | operation, an efficient air-conditioning driving | operation can be performed and energy saving can be aimed at.

The figure which shows the refrigerant circuit of the air conditioner of this invention Diagram showing the refrigeration cycle during cooling operation Diagram showing refrigeration cycle during heating operation Air conditioner control block diagram Flow chart of air conditioning operation when thermo is off Control flow chart of flow rate adjustment device when thermo is off

  The air conditioner of this embodiment is provided with the refrigerant circuit which connected the compressor 1, the condenser 2, the expansion valve 3, and the evaporator 4 with piping, as shown in FIG. A compressor 1, a condenser 2, an expansion valve 3, and an evaporator 4 are arranged in this order from the upstream side along the flow direction of the refrigerant.

  In order to adjust the flow rate of the refrigerant flowing through the refrigerant circuit, a receiver 5 for collecting the refrigerant is provided in the refrigerant circuit. The receiver 5 is connected to the refrigerant circuit via the flow rate adjusting devices 6 and 7. The receiver 5 is arranged in parallel with the expansion valve 3. A connecting pipe branched from the pipe on the upstream side of the expansion valve 3 is connected to the inlet of the receiver 5, and a connecting pipe branched from the pipe on the downstream side of the expansion valve 3 is connected to the outlet of the receiver 5. The upstream connecting pipe is connected between the condenser 2 and the expansion valve 3, and the downstream connecting pipe is connected between the expansion valve 3 and the evaporator 4. A high-pressure flow rate adjustment device 6 is interposed in the upstream connection pipe, and a low-pressure flow rate adjustment device 7 is interposed in the downstream connection pipe.

  The expansion valve 3 is a throttle device that adjusts the flow rate or pressure of the refrigerant. As the throttle device, a plurality of capillary tubes may be arranged to switch the flow path. Further, the flow rate adjusting devices 6 and 7 control the flow of the refrigerant in the branch pipe by opening and closing the pipe of the refrigerant circuit and the receiver 5 so as to communicate with each other or to block the receiver 5 from the pipe. That is, the flow rate adjusting devices 6 and 7 adjust the pressure of the refrigerant in the receiver 5, and use an expansion valve, a flow rate adjusting valve, a stop valve, and the like.

  This air conditioner is a separate type composed of an indoor unit 10 and an outdoor unit 11. The air conditioner performs air conditioning operations such as cooling operation and heating operation. As shown in FIGS. 2 and 3, a four-way valve 12 is provided in the refrigerant circuit. An indoor heat exchanger 13 is arranged in the indoor unit 10, and a compressor 1, a four-way valve 12, an outdoor heat exchanger 14, the expansion valve 3 and the receiver 5 are arranged in the outdoor unit 11. A blower is provided for each of the heat exchangers 13 and 14. In the figure, 15 is a two-way valve used for charging refrigerant, 16 is a three-way valve, and 17 is a two-way valve for bypass piping. Further, a first flow rate adjusting device 18 is interposed between the receiver 5 and the outdoor heat exchanger 14, and a second flow rate adjusting device 19 is interposed between the receiver 5 and the indoor heat exchanger 13. .

  The refrigerant discharged from the compressor 1 is switched in the flow direction by the four-way valve 12 according to the air conditioning operation, and the refrigerant returns to the compressor 1 through the condenser 2, the expansion valve 3, and the evaporator 4. In this way, a refrigeration cycle is formed in which the refrigerant circulates through the refrigerant circuit. As shown in FIG. 2, during the cooling operation or the defrosting operation, the indoor heat exchanger 13 serves as an evaporator and the outdoor heat exchanger 14 serves as a condenser. The first flow rate adjusting device 18 becomes a high pressure side flow rate adjusting device, and the second flow rate adjusting device 19 becomes a low pressure side flow rate adjusting device. As shown in FIG. 3, during the heating operation, the indoor heat exchanger 13 serves as a condenser, and the outdoor heat exchanger 14 serves as an evaporator. The second flow rate adjusting device 19 becomes a high pressure side flow rate adjusting device, and the first flow rate adjusting device 18 becomes a low pressure side flow rate adjusting device.

  As shown in FIG. 4, the air conditioner includes a control device 20 that controls the refrigeration cycle and controls the air conditioning operation. The air conditioner includes a condenser temperature sensor 21 that detects the temperature of the condenser 2, an evaporator temperature sensor 22 that detects the temperature of the evaporator 4, and a discharge temperature that detects the discharge temperature of the refrigerant discharged from the compressor 1. A sensor 23, a room temperature sensor 24, and an outside air temperature sensor 25 are provided. The control device 20 controls the operation of the compressor 1, the blower 26, the expansion valve 3, and the flow rate adjusting devices 6 and 7 to control the refrigeration cycle based on the outputs of these temperature sensors according to the desired air conditioning operation. To do.

  The control device 20 includes an indoor control unit provided in the indoor unit 10 and an outdoor control unit provided in the outdoor unit 11. The indoor control unit and the outdoor control unit are connected so as to be communicable with each other, and both cooperate to control operations of the indoor unit 10 and the outdoor unit 11.

  When the air conditioning operation is performed, the control device 20 controls the refrigeration cycle so that the room temperature becomes the set temperature. At this time, the control apparatus 20 adjusts so that the refrigerant | coolant amount which circulates through a refrigerant circuit becomes optimal according to an air conditioning driving | operation. A part of the refrigerant filled in the refrigerant circuit is accumulated in the receiver 5, and the remaining refrigerant circulates in the refrigerant circuit. Of the circulating refrigerant quantity, the refrigerant quantity when the COP is maximized is determined as the optimum refrigerant quantity. The optimum amount of refrigerant varies depending on the cooling operation or heating operation, and also varies depending on the rotation speed of the compressor 1 and the outside air temperature.

  When the air conditioning operation starts, the control device 20 sets the target rotational speed of the compressor 1 based on the set temperature and the room temperature, and determines the opening degree of the expansion valve 3 according to the target rotational speed. The control device 20 controls the compressor 1, the expansion valve 3, the blower 26, and the like according to the determined operating conditions.

  And the control apparatus 20 will perform refrigerant | coolant amount adjustment control so that it may become the optimal refrigerant | coolant amount, if an air-conditioning driving | operation is started and the driving | operation of the compressor 1 is started. In the refrigerant amount adjustment control, each flow rate adjusting device 6, 7 depends on the operation status such as the type of air conditioning operation (cooling operation, heating operation), the discharge temperature, the rotational speed of the compressor 1, the room temperature, the outside air temperature, and the set temperature. Is set.

  In general, the capacity of the outdoor heat exchanger 14 is larger than the capacity of the indoor heat exchanger 13. Therefore, more refrigerant is required during the cooling operation. The optimum refrigerant amount during the cooling operation is larger than the optimum refrigerant amount during the heating operation. That is, the cooling operation and the dehumidifying operation are the air conditioning operation with a large amount of the optimum refrigerant, and the heating operation is the air conditioning operation with a small amount of the optimum refrigerant.

  When performing the refrigerant amount adjustment control, the control device 20 determines the opening amounts of the high-pressure side and low-pressure side flow rate adjustment devices 6 and 7 based on the current operation state, and each flow rate adjustment device so that the determined opening amount is obtained. 6 and 7 are controlled. Note that the opening degree of each of the flow rate adjusting devices 6 and 7 corresponding to the operating state is determined in advance by experiments or the like and stored in the memory. During the air conditioning operation, the control device 20 reads the opening degree of each of the flow rate adjusting devices 6 and 7 according to the current operation state from the memory, and operates each of the flow rate adjusting devices 6 and 7 according to the read opening degree. The high-pressure side flow rate adjusting device 6 and the low-pressure side flow rate adjusting device 7 are the same type of flow rate adjusting device. For example, as a flow rate adjusting device, the opening degree can be varied between 0 and 256 stages, the opening area can be varied according to the opening degree, and the amount of refrigerant passing therethrough can be varied. Accordingly, the degree of opening of each flow rate adjusting device 6, 7 corresponds to the amount of refrigerant passing through the flow rate adjusting devices 6, 7. As the opening degree increases, the amount of refrigerant passing therethrough increases.

  The refrigerant amount adjustment control is executed from the time when the operation of the compressor 1 is started. That is, when an operation instruction is input such as when an operation signal is received from the remote controller or when a reservation time is reached due to timer reservation, the control device 20 starts the air conditioning operation and operates the compressor 1. At this time, the control device 20 determines the opening degrees of the high-pressure side flow rate adjustment device 6 and the low-pressure side flow rate adjustment device 7 based on the operation state. At the start of this operation, the type of air conditioning operation is confirmed as the operation status. The control device 20 determines the type of air conditioning operation to be started based on the operation signal from the remote controller or timer reservation information.

  In the case of the cooling operation, since the optimum refrigerant amount is large, the refrigerant is not accumulated in the receiver 5. The control device 20 operates the flow rate adjusting devices 6 and 7 so that the refrigerant amount passing through the high pressure side flow rate adjusting device 6 is smaller than the refrigerant amount passing through the low pressure side flow rate adjusting device 7. That is, the opening degree of the low pressure side flow rate adjustment device 7 is made larger than the opening degree of the high pressure side flow rate adjustment device 6. Alternatively, the low pressure side flow rate adjustment device 7 is opened and the high pressure side flow rate adjustment device 6 is closed. For example, the first flow rate adjusting device 18 is closed and the second flow rate adjusting device 19 is opened.

  The refrigerant circulating in the refrigerant circuit is decompressed by the expansion valve 3. When the opening of the high-pressure side flow control device 6 is small or closed, a little refrigerant flows into the receiver 5 or no refrigerant flows. The pressure of the refrigerant that has passed through the expansion valve 3 decreases, and a pressure difference from the refrigerant in the receiver 5 occurs. Since the pressure in the receiver 5 is high, the refrigerant in the receiver 5 is discharged from the receiver 5 and flows into the refrigerant circuit through the open low-pressure flow rate adjusting device 7. The refrigerant does not accumulate in the receiver 5, and the amount of refrigerant circulating in the refrigerant circuit increases.

  In the case of heating operation, since the optimum amount of refrigerant is small, the refrigerant is stored in the receiver 5. The control device 20 operates the flow rate adjusting devices 6 and 7 so that the refrigerant amount passing through the high pressure side flow rate adjusting device 6 is larger than the refrigerant amount passing through the low pressure side flow rate adjusting device 7. That is, the opening degree of the high pressure side flow rate adjustment device 6 is made larger than the opening degree of the low pressure side flow rate adjustment device 7. Alternatively, the high pressure side flow rate adjustment device 6 is opened and the low pressure side flow rate adjustment device 7 is closed. For example, the first flow rate adjusting device 18 is closed and the second flow rate adjusting device 19 is opened.

  The refrigerant flows into the receiver 5 by opening the high pressure side flow rate adjusting device 6. On the other hand, in the low pressure side flow rate adjusting device 7, since the opening degree is small or closed, a little refrigerant is discharged from the receiver 5 or is not discharged. Therefore, the amount of refrigerant accumulated in the receiver 5 increases, and the amount of refrigerant circulating in the refrigerant circuit decreases.

  As described above, since the air conditioning operation is started, the flow rate adjusting devices 6 and 7 are controlled so that the refrigerant circulating through the refrigerant circuit has the optimum refrigerant amount, so that the air conditioning capacity is increased immediately after the operation is started. be able to. Accordingly, the operation efficiency can be improved quickly and energy saving operation can be realized.

  As another method for determining the type of air-conditioning operation, the type of air-conditioning operation started based on room temperature is determined. The control device 20 acquires room temperature information from the room temperature sensor 24 when an operation instruction from a remote controller or the like is input. The control device 20 determines the type of air conditioning operation based on the current room temperature. The timing for discriminating the type of the air-conditioning operation based on the room temperature is set before the start of the operation after the operation instruction is input or immediately after the start of the operation.

  The current room temperature T is compared with the first specified temperature Tw and the second specified temperature Tc (Tw <Tc). When the current room temperature T is equal to or lower than the first specified temperature Tw (T ≦ Tw), the control device 20 determines that the heating operation is being performed. When the current room temperature T is equal to or higher than the second specified temperature Tc (T ≧ Tc), the control device 20 determines that the cooling operation is being performed.

  In the case of Tw <T <Tc, the control device 20 determines that it is a blowing operation. In the case of the air blowing operation, the control device 20 operates the air blower 26 of the indoor unit 10. Since the control of the refrigeration cycle is not performed, the refrigerant amount adjustment control is not performed. In addition, each flow volume adjustment apparatus 6 and 7 is made into the open state. Thus, the method of discriminating the type of the air-conditioning operation based on the room temperature is useful when the automatic operation for automatically selecting the cooling operation or the heating operation according to the room temperature is performed.

  When the air conditioning operation for cooling or heating is performed, when the operation of the compressor 1 is started, the temperature of the refrigerant discharged from the compressor 1 gradually increases. When the discharge temperature becomes almost constant, the refrigeration cycle is stabilized. After the refrigeration cycle is stabilized, the control device 20 continues the refrigerant amount adjustment control.

  If there is a temperature difference between the room temperature and the set temperature during the air conditioning operation, the control device 20 changes the rotation speed of the compressor 1 and the opening degree of the expansion valve 3 so that the temperature difference becomes small. At this time, the control device 20 adjusts the opening degree of the high-pressure side and low-pressure side flow rate adjusting devices 6 and 7 according to the rotational speed of the compressor 1, the outside air temperature, and the like. For example, when the rotation speed of the compressor 1 increases, the control device 20 reduces the opening of the high-pressure side flow rate adjustment device 6 or the low-pressure side flow rate adjustment device 7 in response to an increase in the optimum refrigerant amount. Increase the opening. When the rotational speed of the compressor 1 decreases, the control device 20 increases the opening of the high-pressure side flow control device 6 or the opening of the low-pressure flow control device 7 in response to the decrease in the optimum refrigerant amount. Make it smaller.

  As shown in FIG. 5, the room temperature reaches the set temperature after a certain amount of time has elapsed after the start of the air conditioning operation. The control device 20 stops the compressor 1 and operates only the blower 26. And if a temperature difference arises between room temperature and preset temperature, the control apparatus 20 will start the driving | operation of the compressor 1 again. In this way, during the air conditioning operation, the thermo-off that repeats the on / off operation of the compressor 1 is performed.

  The refrigerant amount adjustment control is also performed when the thermostat is off. The control device 20 adjusts the opening degree of the high-pressure side and low-pressure side flow rate adjusting devices 6 and 7 when the compressor 1 starts operation when the thermostat is off. The opening degree of each flow rate adjusting device 6, 7 is adjusted according to the rotational speed of the compressor 1. That is, when the compressor 1 stops due to the thermo-off, the control device 20 stores in the memory the rotational speed of the compressor 1 and the opening degree of each flow rate adjusting device 6, 7 before the stop. Then, when starting the operation of the compressor 1, the control device 20 determines the rotational speed of the compressor 1 based on the current room temperature, and sets the opening degree of each of the flow rate adjusting devices 6 and 7 according to this rotational speed. To do.

  As shown in FIG. 6, the air conditioning operation is performed with the rotational speed of the compressor 1 being A, and the opening degrees of the high pressure side flow rate adjustment device 6 and the low pressure side flow rate adjustment device 7 being a1 and a2. When the room temperature reaches the set temperature, the control device 20 stops the compressor 1 and performs a blowing operation. When the room temperature changes and a temperature difference occurs between the room temperature and the set temperature, the control device 20 starts the operation of the compressor 1. The control device 20 determines the rotational speed B of the compressor 1 according to the temperature difference between the room temperature and the set temperature, and determines the opening degree of each of the flow rate adjusting devices 6 and 7 according to this rotational speed.

  When starting the operation of the compressor 1 in the thermo-off state, the control device 20 once fully opens the expansion valve 3 and the flow rate adjusting devices 6 and 7, and balances the pressure of the refrigerant circuit. Thereafter, the control device 20 operates the expansion valve 3 and the flow rate adjustment devices 6 and 7 so that the determined opening degree is obtained, and then operates the compressor 1.

  Here, when the rotational speed A before the compressor 1 stops and the rotational speed B at the start of operation, the opening degree of each of the flow rate adjusting devices 6 and 7 is changed from the opening degree before the operation stop. Are b1 and b2, respectively. The control device 20 stores the rotation speed B of the changed compressor 1 and the opening degrees b1 and b2 of the flow rate adjusting devices 6 and 7 as initial values in the memory. The control device 20 once opens each of the flow rate adjusting devices 6 and 7 to a predetermined opening degree. Thereafter, the air conditioning operation is performed until the room temperature reaches the set temperature. For example, when the rotational speed of the compressor 1 increases, the control device 20 decreases the opening of the high-pressure side flow control device 6 and the opening of the low-pressure flow control device 7 as the optimum refrigerant amount increases. Increase

  Thus, by adjusting the opening degree of the flow rate adjusting devices 6 and 7 according to the rotation speed of the compressor 1 at the start of the operation of the compressor 1, the room temperature can be quickly set to the set temperature, and the user's comfort Can be improved. Moreover, the time which the compressor 1 stops becomes long and can implement | achieve an energy saving driving | operation.

  When the rotational speed A before the compressor 1 stops and the rotational speed B at the start of operation are the same, the opening degree of each of the flow rate adjusting devices 6 and 7 is made the same as the opening degree before the operation stop. The opening degree of each of the flow rate adjusting devices 6 and 7 is fixed to a1 and a2, respectively. In this case, the expansion valve 3 and the flow rate adjusting devices 6 and 7 are not fully opened, and the operation of the compressor 1 is resumed with the opening degree as it is. Thus, since it is not necessary to adjust the opening degree of the expansion valve 3 or the like, the operation of the compressor 1 can be started immediately, and the time until the room temperature is set to the set temperature can be shortened. In addition, since the operating conditions do not change, the optimum refrigerant amount can be obtained immediately, efficient operation can be performed, and energy can be saved.

  By the way, when there is a change in the operating state during the air conditioning operation, the control device 20 controls the high-pressure side flow rate adjusting device 6 and the low-pressure side flow rate adjusting device 7 according to the change in the operating state. In particular, the opening degree of each of the flow rate adjusting devices 6 and 7 is adjusted according to the outside air temperature detected by the outside air temperature sensor 25.

  When the outside air temperature at the start of operation of the compressor 1 changes from the outside air temperature when the compressor 1 is stopped, the control device 20 determines the rotation speed of the compressor 1 based on the outside air temperature and the room temperature. For example, during the cooling operation, when the outside air temperature rises, the rotational speed of the compressor 1 is increased from the rotational speed before stopping. In accordance with this rotational speed, the opening degree of the high pressure side flow rate adjustment device 6 is reduced and the opening degree of the low pressure side flow rate adjustment device 7 is increased so that the amount of refrigerant circulating in the refrigerant circuit increases. Similarly, when the outside air temperature decreases, the opening degree of each of the flow rate adjusting devices 6 and 7 is adjusted so that the amount of refrigerant circulating in the refrigerant circuit is reduced. Similarly, in the case of heating operation, the optimum refrigerant amount increases and decreases according to changes in the outside air temperature, so that the opening degree of each of the flow rate adjusting devices 6 and 7 is adjusted so that the circulating refrigerant amount increases and decreases. .

  In this way, by adjusting the opening degree of the flow rate adjusting devices 6 and 7 according to the change in the outside air temperature, the refrigerant circulates through the refrigerant circuit with the optimum refrigerant amount even if the operating state changes. Therefore, efficient operation can be performed and energy saving can be achieved.

  In addition, this invention is not limited to the said embodiment, Of course, many corrections and changes can be added to the said embodiment within the scope of the present invention. The receiver has a structure in which an outlet and an inlet are formed separately, but may be a receiver having a structure having one inlet / outlet. In the receiver having this structure, one pipe connected to the entrance / exit is branched and connected to the upstream connecting pipe and the downstream connecting pipe, respectively.

  During the air conditioning operation, there may be a case of switching to a different type of air conditioning operation. For example, the defrosting operation is performed during the heating operation. Since the defrosting operation is a cooling operation, when the defrosting operation is started, the control device adjusts the opening degrees of the high pressure side flow rate adjustment device and the low pressure side flow rate adjustment device so that the optimum refrigerant amount increases. Since the air conditioning capability in the defrosting operation is increased, the defrosting can be performed in a short time.

  Depending on the air conditioner, there are cases where the air conditioning operation with a small amount of optimum refrigerant is a cooling operation and the air conditioning operation with a large amount of optimum refrigerant is a heating operation. Also in such an air conditioner, the refrigerant amount can be adjusted so that the optimum refrigerant amount is obtained from the start of operation by adjusting the opening degrees of the high-pressure side flow rate adjusting device and the low-pressure side flow rate adjusting device.

  Different types may be used for the high pressure side flow rate adjustment device and the low pressure side flow rate adjustment device. In this case, the relationship between the opening degree of each flow control device and the amount of refrigerant passing therethrough varies depending on the type used. The relationship between the opening degree of each flow control device and the amount of refrigerant passing therethrough is determined in advance by experiments or the like and stored in the memory. When discharging the refrigerant from the receiver, the control device controls the opening degree of each flow rate adjustment device so that the refrigerant amount passing through the low pressure side flow rate adjustment device is larger than the refrigerant amount passing through the high pressure side flow rate adjustment device. When the refrigerant is stored in the receiver, the opening degree of each flow rate adjusting device is controlled so that the amount of refrigerant passing through the high pressure side flow rate adjusting device is larger than the amount of refrigerant passing through the low pressure side flow rate adjusting device.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 3 Expansion valve 4 Evaporator 5 Receiver 6 High pressure side flow rate adjustment device 7 Low pressure side flow rate adjustment device 10 Indoor unit 11 Outdoor unit 12 Four-way valve 13 Indoor heat exchanger 14 Outdoor heat exchanger 18 First flow rate adjustment Device 19 Second flow control device 20 Control device 21 Condenser temperature sensor 22 Evaporator temperature sensor 23 Discharge temperature sensor 24 Room temperature sensor 25 Outside air temperature sensor

Claims (5)

A refrigerant circuit is formed by connecting a compressor, a condenser, a throttling device, and an evaporator by piping, and a receiver for storing the refrigerant is provided in the refrigerant circuit. The receiver includes a high-pressure side flow control device and a low-pressure side flow control device. The high pressure side flow rate adjustment device and the low pressure side flow rate adjustment device when starting the operation of the compressor so that the refrigerant circulating through the refrigerant circuit has an optimum refrigerant amount according to the type of air conditioning operation. An air conditioner comprising a control device that controls the refrigerant amount by controlling the refrigerant. The control device is configured so that the amount of refrigerant passing through the high-pressure side flow control device is larger than the amount of refrigerant passing through the low-pressure flow control device so that the refrigerant is accumulated in the receiver during air-conditioning operation with a small amount of optimal refrigerant. When air conditioning operation is performed with a large amount of optimum refrigerant by operating the flow regulator and low-pressure flow regulator, the amount of refrigerant passing through the high-pressure flow regulator passes through the low-pressure flow regulator so that the refrigerant does not accumulate in the receiver. 2. The air conditioner according to claim 1, wherein the high-pressure side flow rate adjustment device and the low-pressure side flow rate adjustment device are operated so as to be smaller than a refrigerant amount to be reduced. A room temperature sensor for detecting the room temperature is provided, and the control device determines the type of air conditioning operation based on the room temperature. When the room temperature is high, the controller determines that the air conditioning operation has a large amount of optimal refrigerant. The air conditioner according to claim 1 or 2, wherein it is determined that the air-conditioning operation is less. The operation of the compressor is started in accordance with the start of the air conditioning operation, and the control device controls the high pressure side flow rate adjustment device and the low pressure side flow rate adjustment device before or immediately after the start of the air conditioning operation. Item 4. The air conditioner according to any one of Items 1 to 3. The air conditioner according to any one of claims 1 to 4, wherein the control device controls the high-pressure side flow rate adjustment device and the low-pressure side flow rate adjustment device when the operation of the compressor is started when the thermostat is off.

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