JP5903585B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner including a bypass circuit connecting between an outdoor heat exchanger and a four-way valve, between the four-way valve and a suction port of a compressor, and a three-way valve in the bypass circuit.

  Conventionally, during a heating operation by a heat pump type air conditioner, if the state in which the room temperature exceeds the target temperature is continued for a predetermined time, the operation of the compressor is stopped (hereinafter referred to as a thermo-off operation) and the room temperature is excessively increased. It was preventing.

JP-A-2-169949

  However, when the compressor is stopped, the room temperature is suddenly lowered to impair comfort, and a large amount of power is consumed when the compressor is started again after the room temperature is lowered. The present invention has been made in view of such problems of the prior art, and if the state in which the room temperature exceeds the target temperature during a heating operation is continued for a predetermined time, without stopping the compressor, It aims at providing the air conditioner which can perform the driving | operation which maintains comfortable temperature by continuing heating operation.

  In order to achieve the above object, the present invention comprises a refrigeration cycle in which a refrigerant flows in the order of a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, an outdoor heat exchanger, and a four-way valve during heating operation. Bypass circuit for connecting indoor temperature detecting means for detecting the indoor temperature, target temperature setting means for setting the target temperature, between the outdoor heat exchanger and the four-way valve, and between the four-way valve and the suction port of the compressor And (hereinafter referred to as a heat storage bypass circuit) an air conditioner equipped with a three-way valve and a throttle mechanism in the heat storage bypass circuit, and when the state in which the indoor temperature detecting means exceeds the target temperature is continued for a predetermined time, the heat storage bypass Control is performed to open and close the three-way valve so that the refrigerant flows in the circuit.

  According to the present invention, by operating the three-way valve to control the circulation of the refrigerant to the heat storage bypass circuit, the heating operation can be continued without turning off the thermo, and the efficiency can be improved without impairing the comfort. Good driving can be continued.

Piping system diagram of an air conditioner equipped with a heat storage bypass circuit according to the present invention The schematic diagram which shows the operation | movement at the time of normal heating of the air conditioner of FIG. 1, and the flow of a refrigerant | coolant. The schematic diagram which shows the operation | movement at the time of defrosting and heating of the air conditioner of FIG. 1, and the flow of a refrigerant | coolant. The schematic diagram which shows the operation | movement at the time of heat storage three-way valve opening of the air conditioner of FIG. 1, and the flow of a refrigerant | coolant Control flow diagram for control to open and close the heat storage three-way valve

1st invention is related with the air conditioner provided with the refrigerating cycle connected so that a refrigerant might flow in order of a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, an outdoor heat exchanger, and a four-way valve at the time of heating operation. Yes, indoor temperature detection means for detecting the room temperature, target temperature setting means for setting the target temperature, between the outdoor heat exchanger and the four-way valve, and between the four-way valve and the suction port of the compressor A heat storage bypass circuit, a three-way valve and a throttle mechanism are further provided in the heat storage bypass circuit, and the three-way valve is opened and closed so that the refrigerant flows into the heat storage bypass circuit when the room temperature exceeds the target temperature for a predetermined time. The control to operate is performed.

  In this configuration, by performing control to operate the three-way valve, the heating operation can be continued without turning off the thermo, and the efficient operation can be continued without impairing the comfort.

  2nd invention can prevent the rapid fall of blowing temperature by performing control which operates a three-way valve in multiple times.

  In the third aspect of the present invention, it is possible to prevent the discharge temperature from being excessively lowered by providing an upper limit for the number of times of control for operating the three-way valve.

  According to the fourth aspect of the invention, the control for operating the three-way valve is performed based on the indoor heat exchanger temperature, so that the blowing temperature can be maintained at a certain temperature or higher.

  In the fifth aspect of the present invention, the control for operating the three-way valve is not performed while the compressor is stopped. This can prevent excessive operation of the three-way valve.

  6th invention can remove the frost adhering to an outdoor unit reliably by not performing control which operates a three-way valve during the defrost operation which removes the frost of an outdoor heat exchanger.

  In the seventh aspect of the invention, after the control for operating the three-way valve is performed, the control for operating the three-way valve is not performed for a predetermined time, so that the durability of the three-way valve can be ensured without excessively operating the three-way valve.

  According to an eighth aspect of the present invention, a refrigerant heater is provided in the heat storage bypass circuit, and as a result, the temperature at which the three-way valve is controlled to be controlled is higher than that in the case where the refrigerant heater is not provided in the heat storage bypass circuit. Can be kept in a state.

  The ninth invention relates to an air conditioner in which the refrigerant heater is composed of a heat storage material for storing heat of the compressor and a refrigerant flow path in which the refrigerant flows inside the heat storage material. When established, the opening degree of the expansion valve is fully opened, and the three-way valve is operated to perform the defrosting operation. When the defrosting condition is satisfied, even if the room temperature exceeds the target temperature for a predetermined time, the opening degree of the expansion valve is returned to the state before the defrosting operation and control for avoiding the thermo-off is not performed. Heat consumption can be prevented during the defrosting operation.

  A tenth aspect of the invention relates to an air conditioner further comprising a heat storage material temperature detecting means for detecting a heat storage material temperature, and when the heat storage material temperature is lower than a predetermined temperature, the indoor temperature becomes the target temperature. Even if it is in a state exceeding a predetermined time, it is possible to keep the blowing temperature at a high temperature by not performing the control for operating the three-way valve.

  In the eleventh aspect of the invention, the control for operating the three-way valve is performed based on the outside air temperature. Since the possibility of defrosting is high when the outside air temperature is lower than a certain temperature, control to operate the three-way valve is not performed. Since this configuration is intended to take out the heat of the heat storage material during the defrosting operation, heat consumption during the defrosting operation can be prevented by not performing control to operate the three-way valve.

  In the twelfth invention, the control for operating the three-way valve is performed based on the temperature of the outdoor heat exchanger. When the temperature of the outdoor heat exchanger is less than a certain temperature, there is a high possibility of defrosting. Therefore, heat consumption can be prevented during the defrosting operation by not performing control to operate the three-way valve.

  In the thirteenth invention, after the three-way valve is operated and the expansion valve is opened and the defrosting operation is performed, the three-way valve is not opened or closed even when the room temperature exceeds the target temperature for a predetermined time. It was.

  In this configuration, since the possibility of entering the defrosting is high even after the three-way valve is operated and the expansion valve is opened to perform the defrosting operation, the control for operating the three-way valve is not performed. Since this structure is intended to take out the heat of the heat storage material during the defrosting operation, it is possible to prevent the consumption of heat during the defrosting operation by not performing the control for operating the three-way valve.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a configuration of an air conditioner that is a refrigeration cycle apparatus according to the present invention, and the air conditioner includes an outdoor unit 1 and an indoor unit 2 that are connected to each other through a refrigerant pipe.

  As shown in FIG. 1, a compressor 3, a four-way valve 4, an expansion valve 5, an outdoor blower fan 6, and an outdoor heat exchanger 12 are provided inside the outdoor unit 1. An indoor fan 7 and an indoor heat exchanger 11 are provided.

  More specifically, an accumulator 8 for separating the liquid-phase refrigerant and the gas-phase refrigerant is provided on the refrigerant suction side of the compressor 3. In addition, a three-way valve (for example, an electromagnetic valve) 21 and a throttle mechanism 22 are provided between the outdoor heat exchanger 12 and the four-way valve 4.

  Furthermore, a heat storage tank 31 is provided around the compressor 3, and a heat storage heat exchanger 32 is provided inside the heat storage tank 31, and a heat storage material for exchanging heat with the heat storage heat exchanger 32 (for example, An ethylene glycol aqueous solution) is filled, and the heat storage tank 31, the heat storage heat exchanger 32, and the heat storage material constitute a heat storage device.

  These are connected to each other via a refrigerant pipe (not numbered but illustrated by lines connecting components) to constitute a refrigeration cycle.

  In the interior of the indoor unit 2, upper and lower blades (not shown) and left and right blades (not shown) are provided in addition to the indoor heat exchanger 11. The indoor heat exchanger 11 is provided with an indoor blower fan 7. Heat exchange is performed between the indoor air sucked into the indoor unit 2 by the refrigerant flowing through the indoor heat exchanger 11, and the air warmed by heat exchange is blown into the room during heating, while heat exchange is performed during cooling. The air cooled by is blown out into the room. The upper and lower blades change the direction of air blown from the indoor unit 2 up and down as necessary, and the left and right blades change the direction of air blown from the indoor unit 2 to right and left as needed.

  The outdoor heat exchanger 12 is provided with an outdoor heat exchanger inlet temperature detecting means 41 and an outdoor heat exchanger outlet temperature detecting means 42 for detecting the refrigerant inlet temperature and the refrigerant outlet temperature during heating operation, respectively. The exchanger 11 is provided with indoor heat exchanger temperature detecting means 43 that detects the temperature of the indoor heat exchanger 11. Further, the heat storage tank 31 is provided with a heat storage tank temperature detection means 44 for detecting the temperature of the heat storage tank 31, and the outdoor unit 1 is provided with an outside air temperature detection means 45 for detecting the outside air temperature.

Note that the compressor 3, the outdoor fan 6, the indoor fan 7, the upper and lower blades, the left and right blades, the four-way valve 4, the expansion valve 5, the three-way valve 21, the outdoor heat exchanger inlet temperature detection means 41, and the outdoor heat exchanger outlet temperature. The detection means 42, the indoor heat exchanger temperature detection means 43, the heat storage tank temperature detection means 44, the outside air temperature detection means 45, etc. are electrically connected to the controller 51 (for example, a microcomputer), and the compressor 3, the outdoor blower fan 6, The operation or operation of the indoor blower fan 7, the upper and lower blades, the left and right blades, the four-way valve 4, and the expansion valve 5 is controlled based on a control signal from the controller 51, and the three-way valve 21 is based on a control signal from the controller 51. The opening / closing operation is controlled.

  In the refrigeration cycle apparatus according to the present invention having the above-described configuration, the mutual connection relationship and function of each component will be described together with the flow of the refrigerant, taking the case of heating operation as an example.

  The refrigerant discharged from the discharge port of the compressor 3 reaches the indoor heat exchanger 11 from the four-way valve 4 through the refrigerant pipe. The refrigerant condensed by exchanging heat with indoor air in the indoor heat exchanger 11 exits the indoor heat exchanger 11, passes through the refrigerant pipe, and reaches the expansion valve 5. The refrigerant depressurized by the expansion valve 5 reaches the outdoor heat exchanger 12 through the refrigerant pipe, and the refrigerant evaporated by exchanging heat with the outdoor air in the outdoor heat exchanger 12 passes through the refrigerant pipe, the four-way valve 4 and the accumulator 8. It passes through and returns to the suction port of the compressor 3.

  Further, a three-way valve 21 and a throttle mechanism 22 are provided between the outdoor heat exchanger 12 and the four-way valve 4, and a heat storage tank 31 containing a heat storage material and a heat storage heat exchanger 32 is provided in the compressor 3. The heat generated in the compressor 3 is accumulated in the heat storage material, passes through the three-way valve 21 and the throttle mechanism 22, reaches the inlet of the heat storage heat exchanger 32, and exits from the heat storage heat exchanger 32. The refrigerant pipe that has exited joins between the four-way valve 4 and the accumulator 8.

  Next, the operation during normal heating will be described with reference to FIG. 2 schematically showing the operation during normal heating and the flow of the refrigerant of the air conditioner shown in FIG.

  During normal heating operation, the three-way valve 21 is open between AB and C is closed. As described above, the refrigerant discharged from the discharge port of the compressor 3 reaches the indoor heat exchanger 11 from the four-way valve 4 through the refrigerant pipe. The refrigerant condensed by exchanging heat with the indoor air in the indoor heat exchanger 11 exits the indoor heat exchanger 11, passes through the refrigerant pipe, reaches the expansion valve 5, and the refrigerant decompressed by the expansion valve 5 passes through the refrigerant pipe. To the outdoor heat exchanger 12. The refrigerant that has evaporated by exchanging heat with outdoor air in the outdoor heat exchanger 12 returns from the four-way valve 4 through the accumulator 8 to the suction port of the compressor 3 through the refrigerant pipe.

  The heat generated in the compressor 3 is accumulated in the heat storage material accommodated in the heat storage tank 31 from the outer wall of the compressor 3 through the outer wall of the heat storage tank 31.

  Next, the operation during defrosting / heating will be described with reference to FIG. 3 schematically showing the operation of the air conditioner shown in FIG. 1 during defrosting / heating and the flow of refrigerant. 3, the solid line represents the flow of refrigerant discharged from the compressor 3 to the condensation process (high pressure side), and the broken line is decompressed by the throttle mechanism 22 after the condensation process and evaporated (low pressure side). ) And the flow of the refrigerant returning to the compressor 3.

  When the outdoor heat exchanger 12 is frosted during the normal heating operation described above and the frost that has grown grows, the ventilation resistance of the outdoor heat exchanger 12 increases, the air flow decreases, and evaporation in the outdoor heat exchanger 12 occurs. The temperature drops. As shown in FIG. 1, an air conditioner that is a refrigeration cycle apparatus according to the present invention is provided with an outdoor heat exchanger inlet temperature detection means 41 for detecting the refrigerant inlet temperature of the outdoor heat exchanger 12 during heating operation. When the outdoor heat exchanger inlet temperature detection means 41 detects that the evaporation temperature has decreased as compared with the time of non-frosting, the controller 51 outputs an instruction from the normal heating operation to the defrosting / heating operation. .

When the normal heating operation is shifted to the defrosting / heating operation, the three-way valve 21 is operated to open between A and C, and B is closed. At the same time, the opening of the expansion valve 5 is fully opened. In the step where the refrigerant that has passed through the exchanger 11 flows in without being decompressed, the refrigerant is heat-exchanged in the outdoor heat exchanger 12 and is condensed and liquefied in the same manner as the indoor heat exchanger 11. The frost formed on the outdoor heat exchanger 12 is defrosted by the amount of heat released to the outside.

  The refrigerant condensed in the outdoor heat exchanger 12 passes between A and C in the three-way valve 21 and is reduced in pressure by the throttle mechanism 22 to become a liquid phase refrigerant. The heat storage heat exchanger 32 absorbs heat from the heat storage material, evaporates, Phases through the refrigerant pipe and returns from the accumulator 8 to the suction port of the compressor 3.

  As described above, the temperature of the outdoor heat exchanger 12 that has become below freezing due to the attachment of frost at the start of defrosting / heating is heated by condensing the gas-phase refrigerant from the discharge port of the compressor 3 into a liquid layer. When the frost melts near zero degrees and the frost melts, the temperature of the outdoor heat exchanger 12 begins to rise again. When the temperature rise of the outdoor heat exchanger 12 is detected by the outdoor heat exchanger outlet temperature detecting means 42, it is determined that the defrosting is completed, and the controller 51 outputs an instruction from the defrosting / heating operation to the normal heating operation. The

  FIG. 4 illustrates a three-way operation in order to continue the heating operation without stopping the compressor when the room temperature exceeds the target temperature for a predetermined time during the heating operation of the air conditioner shown in FIG. FIG. 5 is a control flow diagram of control for opening and closing the three-way valve, schematically showing the heating operation and the refrigerant flow in a state where the valve is operated.

  Hereinafter, the three-way valve opening / closing control operation during the heating operation will be described with reference to FIGS. 4 and 5.

  After the heating operation is started, in step SP1, it is determined whether or not the compressor 3 is driven. If the compressor 3 is driven, the process proceeds to step SP2, and if the compressor 3 is not driven, the process proceeds to step SP15. .

  In step SP2 advanced from step SP1, when the temperature of the heat storage tank 31 satisfies the condition of a ° C. or higher (for example, 0 ° C.), the process advances to step SP3. If the condition is not satisfied, the blow-out temperature may be remarkably lowered, so the process proceeds to step SP15 without performing this control.

  In step SP3 advanced from step SP2, if the defrosting operation has not been performed once since the start of the heating operation or if A minutes have elapsed (for example, 360 minutes) since the previous defrosting operation was performed, the process proceeds to step SP4. When the defrosting operation is carried out after the start of operation and A has not elapsed, it can be easily assumed to enter the defrosting operation again, so the heat stored in the heat storage material originally used for defrosting, In order to avoid that the three-way valve 21 is released and cannot be used for defrosting, the process proceeds to step SP15 without performing this control.

  In step SP4 that has proceeded from step SP3, if the main control has not been performed once since the start of the heating operation or if B minutes have elapsed (for example, 30 minutes) since the previous main control was performed, the flow proceeds to step SP5 and the heating operation is started. Thereafter, this control is performed, and if the B minutes have not elapsed, the process proceeds to step SP15.

  If the air conditioner is in the process of defrosting in step SP5 advanced from step SP4, in order to fully open the opening of the expansion valve 5 in the defrosting operation, the process proceeds to step SP15 without performing this control. If the defrosting operation is not being performed, the process proceeds to step SP6.

In step SP6 advanced from step SP5, when the outside air temperature is not lower than c ° C. (for example, −5 ° C.), the process proceeds to step SP7, and when the outside air temperature is lower than c ° C., there is a high possibility of entering defrosting (or Therefore, since there is a low possibility that the capacity of heat input into the air conditioner's room is excessive), the process proceeds to step SP15.

  If the temperature of the outdoor heat exchanger 12 is not lower than d ° C. (for example, 2 ° C.) in step SP7 advanced from step SP6, the process proceeds to step SP8, and if the temperature of the outdoor heat exchanger 12 is lower than d ° C. Since there is a high possibility of entering frost, the process proceeds to step SP15.

  In step SP8, a value obtained by subtracting the set temperature from the room temperature is e ° C or higher (for example, 2 ° C), and a state in which the value obtained by subtracting the set temperature from the room temperature is eC or higher is C seconds or longer (for example, 90 seconds). If it is maintained, it is determined that the amount of heat input into the room is excessive, and the process proceeds to step SP9 where the value obtained by subtracting the set temperature from the room temperature is less than e ° C or the value obtained by subtracting the set temperature from the room temperature is d ° C. When the above state is not maintained for C seconds or more, the process proceeds to step SP15.

  In step SP9 that has advanced from step SP8, when the temperature of the indoor heat exchanger 11 is equal to or higher than f ° C. (for example, 40 ° C. or higher), execution of this control is permitted, and the flow advances to SP10 to start this control. When the temperature of the indoor heat exchanger 11 is less than f ° C., the process proceeds to step SP15.

  In the present control started in step SP9 that has advanced from step SP8, the three-way valve 21 is operated in step SP10 to open between A and C, and AB is closed. The opening between A and C is performed for D seconds (for example, 3 seconds). Thereafter, in step SP11, the three-way valve 21 is operated to open between A and B, and A and C are closed.

  In step SP12, after E seconds (for example, 20 seconds) when the three-way valve 21 is operated and the passage between A and B is opened in step SP11, the passage between the A and B of the three-way valve 21 is opened. It is determined again whether the temperature is equal to or higher than f ° C. When the temperature of the indoor heat exchanger 11 is equal to or higher than f ° C, the process proceeds to step SP13. When the temperature of the indoor heat exchanger 11 is lower than f ° C, step SP14 is performed. Proceed to and end this control.

  In step SP13, when the number of times the three-way valve 21 is operated reaches the maximum number F of the main control (for example, three times), the process proceeds to step SP14, the present control is terminated, the process proceeds to step SP15, and the three-way valve 21 is opened. When the operation has not reached the maximum number F of the main control, the process returns to step SP10 and the three-way valve 21 is operated again.

  In step SP15, if the operation stop is not selected, the operation is continued, and the process returns to step SP1, and if the operation is stopped, the operation is stopped.

  By carrying out the above control, when the three-way valve 21 is operated and the circuit between A and C is opened during the main control after step SP9, the liquid refrigerant is evaporated and vaporized in the outdoor heat exchanger 12, and then the three-way It passes between A and C of the valve 21 and becomes a gas-phase refrigerant that is further reduced in pressure and reduced in pressure by the throttle mechanism 22 and reaches the heat storage heat exchanger 32. The refrigerant exchanges heat with the heat storage material filled in the heat storage tank 31 and stores the amount of heat radiated by the compressor 3, and absorbs heat. However, since it is in the gas phase, the temperature rises but the phase does not change. By passing through the heat storage heat exchanger 32, the pressure is further reduced due to the generated pressure loss and returns to the compressor 3 via the accumulator 8.

  As a result, the discharge pressure of the compressor 3 being controlled is lower than that during normal heating operation, and the saturation pressure (high pressure) of the indoor heat exchanger 11 is temporarily reduced. This action makes it possible to continue the heating operation without performing the thermo-off.

Since the air conditioner according to the present invention uses the heat storage bypass circuit and the three-way valve to enable the heating operation without performing the thermo-off operation, it can be effectively used for other refrigeration cycle apparatuses that perform the thermo-off operation in winter. it can.

DESCRIPTION OF SYMBOLS 1 Outdoor unit 2 Indoor unit 3 Compressor 4 Four-way valve 5 Expansion valve 6 Outdoor ventilation fan 7 Indoor ventilation fan 8 Accumulator 11 Indoor heat exchanger 12 Outdoor heat exchanger 21 Three-way valve 22 Throttle mechanism 31 Thermal storage tank 32 Thermal storage heat exchanger 41 Outdoor heat exchanger inlet temperature detection means 42 Outdoor heat exchanger outlet temperature detection means 43 Indoor heat exchanger temperature detection means 44 Thermal storage tank temperature detection means 45 Outdoor air temperature detection means 51 Controller,

Claims (12)

This relates to an air conditioner having a refrigeration cycle connected so that refrigerant flows in the order of a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, an outdoor heat exchanger, and a four-way valve during heating operation. An indoor temperature detecting means for detecting, a target temperature setting means for setting a target temperature, a heat storage bypass circuit connecting between the outdoor heat exchanger and the four-way valve, and between the four-way valve and the suction port of the compressor; A heat storage bypass circuit is further provided with a three-way valve and a throttle mechanism, and when the room temperature exceeds the target temperature for a predetermined time , the opening and closing operation of the three-way valve is repeated multiple times so that the refrigerant flows in the heat storage bypass circuit. Air conditioner characterized by. The air conditioner according to claim 1 , wherein an upper limit number of times of operating the three-way valve is provided. The air conditioner according to any one of claims 1 to 2 , wherein control for operating the three-way valve is performed based on a temperature of the indoor heat exchanger. The air conditioner according to any one of claims 1 to 3 , wherein control for operating the three-way valve is not performed while the compressor is stopped. The air conditioner according to any one of claims 1 to 4 , wherein control for operating the three-way valve is not performed during a defrosting operation for removing frost in the outdoor heat exchanger. The air according to any one of claims 1 to 5 , wherein the control for operating the three-way valve is not performed for a predetermined time after the control for operating the three-way valve and the expansion valve is performed. Harmony machine. The air conditioner according to any one of claims 1 to 6 , wherein a refrigerant heater is provided in the heat storage bypass circuit. The refrigerant heater is composed of a heat storage material for storing heat of the compressor and a refrigerant flow path through which the refrigerant flows inside the heat storage material, and when the defrost condition is satisfied, the opening degree of the expansion valve is increased. The air conditioner according to claim 1 , wherein the defrosting operation is performed by operating the three-way valve with the valve fully open, and when the defrost condition is satisfied, even if the indoor temperature is higher than the target temperature, An air conditioner characterized by not performing control to operate the three-way valve. A heat storage material temperature detecting means for detecting the temperature of the heat storage material is provided, and when the temperature of the heat storage material is lower than a predetermined temperature, even if the state where the indoor temperature exceeds the target temperature continues for a predetermined time, The air conditioner according to claim 8 , wherein control for operating the three-way valve is not performed. The air conditioner according to claim 8 or 9 , wherein control for operating the three-way valve is performed based on an outside air temperature. The air conditioner according to any one of claims 8 to 10 , wherein the control for operating the three-way valve is performed based on a temperature of the outdoor heat exchanger. After the opening degree of the expansion valve is fully opened and the three-way valve is operated to perform the defrosting operation, the control for operating the three-way valve is performed even if the room temperature exceeds the target temperature for a predetermined time. It does not perform, The air conditioner of any one of Claim 8 to 11 characterized by the above-mentioned.