JPWO2019043941A1 - Air conditioner - Google Patents

Abstract

The air conditioner includes a refrigerant circuit in which a compressor, an outdoor heat exchanger, an expansion unit, and an indoor heat exchanger are connected by piping, and a refrigerant circuit, and an indoor temperature detector that detects the temperature of the refrigerant flowing in the indoor heat exchanger. And a control unit for controlling the compressor, wherein the control unit sets a target temperature range of the refrigerant flowing through the indoor heat exchanger based on the indoor set temperature, and an indoor temperature detection unit. Compression control means for controlling the compressor such that the temperature of the refrigerant detected by the setting means falls within the range of the target temperature set by the setting means.

Description

  The present invention relates to an air conditioner that controls the temperature of a refrigerant flowing through an indoor heat exchanger.

  BACKGROUND ART Conventionally, an air conditioner that controls the temperature of a refrigerant flowing in an indoor heat exchanger has been known. When the cooling operation is being performed, the indoor heat exchanger acts as an evaporator. As the evaporation temperature of the refrigerant flowing through the indoor heat exchanger is lower, the difference from the indoor set temperature becomes larger, and the room is further cooled. In addition, the higher the evaporation temperature, the smaller the difference from the set temperature in the room, and the more difficult it is to cool the room. On the other hand, when the heating operation is being performed, the indoor heat exchanger acts as a condenser. The higher the condensation temperature of the refrigerant flowing in the indoor heat exchanger, the greater the difference from the set temperature in the room, and the more the room is heated. In addition, the lower the condensation temperature, the smaller the difference from the set temperature in the room, and the more difficult the room is to be heated. Patent Literature 1 calculates an air-conditioning load based on a temperature difference between an indoor set temperature and an outdoor temperature, and calculates an evaporation temperature during cooling operation and a condensing temperature during heating operation according to the calculated air-conditioning load. An air conditioner controlled by changing the capacity of a compressor is disclosed.

JP-A-2002-147823

  In the air conditioner disclosed in Patent Document 1, when the outdoor temperature is low and the indoor set temperature is set high during cooling, the difference between the set temperature and the outdoor temperature becomes small. Therefore, the air conditioner reduces the capacity of the compressor. As a result, there is a possibility that the air conditioning capacity becomes insufficient. Conventionally, there is also known a technique of controlling an evaporation temperature during cooling based on only an outdoor temperature regardless of a set indoor temperature. When the outdoor temperature is low, the lower limit of the evaporation temperature is raised in order to suppress excessive cooling. However, since the upper limit of the evaporating temperature does not change, even if the set temperature is set high, the difference between the evaporating temperature and the set temperature is not reduced, and there is a possibility that excessive cooling is performed.

  The present invention has been made in order to solve the above-described problem, and provides an air conditioner that performs a cooling operation or a heating operation without excess or shortage.

  The air conditioner according to the present invention includes a refrigerant circuit in which a compressor, an outdoor heat exchanger, an expansion unit, and an indoor heat exchanger are connected by piping, a refrigerant circuit, and a temperature of the refrigerant flowing in the indoor heat exchanger. An internal temperature detection unit, and a control unit for controlling the compressor, wherein the control unit sets a target temperature range of the refrigerant flowing through the indoor heat exchanger based on the indoor set temperature, Compression control means for controlling the compressor such that the temperature of the refrigerant detected by the inside temperature detection section falls within the range of the target temperature set by the setting means.

  According to the present invention, the target temperature range is set based on the indoor set temperature, and the compressor is controlled to fall within the set target temperature range. For this reason, regardless of the outdoor temperature, a cooling operation or a heating operation that is sufficient for the user is performed according to the indoor set temperature.

1 is a circuit diagram showing an air conditioner 1 according to Embodiment 1 of the present invention. FIG. 2 is a block diagram illustrating a control unit 10 of the air-conditioning apparatus 1 according to Embodiment 1 of the present invention. 5 is a graph showing a range of a target temperature of the evaporation temperature Te according to the first embodiment of the present invention. 5 is a graph showing a target temperature range of a condensing temperature Tc according to the first embodiment of the present invention. 5 is a flowchart showing an operation of the air-conditioning apparatus 1 according to Embodiment 1 of the present invention. It is a block diagram showing control part 110 of air conditioner 100 concerning Embodiment 2 of the present invention. 6 is a flowchart illustrating an operation of the air-conditioning apparatus 100 according to Embodiment 2 of the present invention.

Embodiment 1 FIG.
Hereinafter, an embodiment of an air conditioner according to the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram showing an air conditioner 1 according to Embodiment 1 of the present invention. As shown in FIG. 1, the air conditioner 1 is a device that adjusts air in an indoor space, and includes an outdoor unit 2 and an indoor unit 3. The outdoor unit 2 is provided with a compressor 5, a flow path switching device 6, an outdoor heat exchanger 7, an expansion unit 8, and an outdoor control device 11. The indoor unit 3 includes an indoor heat exchanger 9, an indoor-side temperature detector 13, a human detector 14, and an indoor controller 12. Further, a remote controller 4 is connected to the indoor unit 3. The remote controller 4 is operated by the user of the air-conditioning apparatus 1, and sets the input indoor set temperature Tset and the like. In the first embodiment, the control unit 10 is configured by the outdoor control device 11 and the indoor control device 12, but the control unit 10 may be provided only in the outdoor unit 2 or may be provided in the indoor unit 3 Only, or may be provided as a separate unit.

  The compressor 5, the flow switching device 6, the outdoor heat exchanger 7, the expansion section 8, and the indoor heat exchanger 9 are connected by piping to form a refrigerant circuit. The compressor 5 sucks a refrigerant in a low-temperature and low-pressure state, compresses the sucked refrigerant into a high-temperature and high-pressure refrigerant, and discharges the refrigerant. The flow path switching device 6 switches the direction in which the refrigerant flows in the refrigerant circuit, and is, for example, a four-way valve. The outdoor heat exchanger 7 exchanges heat between outdoor air and a refrigerant, for example. The outdoor heat exchanger 7 functions as a condenser during the cooling operation, and functions as an evaporator during the heating operation.

  The expansion section 8 is a pressure reducing valve or an expansion valve that expands by reducing the pressure of the refrigerant. The expansion section 8 is, for example, an electronic expansion valve whose opening is adjusted. The indoor heat exchanger 9 exchanges heat, for example, between indoor air and a refrigerant. The indoor heat exchanger 9 functions as an evaporator during the cooling operation, and functions as a condenser during the heating operation.

  The indoor-side temperature detector 13 is provided on a pipe to which the indoor heat exchanger 9 is connected, and detects the temperature of the refrigerant flowing through the indoor heat exchanger 9. Here, the temperature of the refrigerant flowing through the indoor heat exchanger 9 acting as the evaporator during the cooling operation is referred to as the evaporation temperature Te, and the temperature of the refrigerant flowing through the indoor heat exchanger 9 acting as the condenser during the heating operation is referred to as the condensing temperature. Called Tc. The human detection unit 14 includes, for example, a human sensor and detects the presence or absence of a human in the room. The outdoor control device 11 controls the operation of each device provided in the outdoor unit 2, and is connected to the indoor control device 12. The indoor control device 12 controls the operation of each device provided in the indoor unit 3, and is connected to the remote controller 4 and the outdoor control device 11.

(Operation mode, cooling operation)
Next, an operation mode of the air conditioner 1 will be described. First, the cooling operation will be described. In the cooling operation, the refrigerant sucked into the compressor 5 is compressed by the compressor 5 and discharged in a high-temperature and high-pressure gas state. The high-temperature and high-pressure gaseous refrigerant discharged from the compressor 5 passes through the flow path switching device 6 and flows into the outdoor heat exchanger 7 acting as a condenser. Heat exchanges with and condenses and liquefies. The condensed refrigerant in the liquid state flows into the expansion section 8 and is expanded and decompressed in the expansion section 8 to become a low-temperature, low-pressure gas-liquid two-phase refrigerant. Then, the refrigerant in the gas-liquid two-phase state flows into the indoor heat exchanger 9 acting as an evaporator, where the refrigerant exchanges heat with indoor air to evaporate and gasify. At this time, the room air is cooled and the room is cooled. The evaporated low-temperature and low-pressure gaseous refrigerant passes through the flow path switching device 6 and is sucked into the compressor 5.

(Operation mode, heating operation)
Next, the heating operation will be described. In the heating operation, the refrigerant drawn into the compressor 5 is compressed by the compressor 5 and discharged in a high-temperature and high-pressure gas state. The high-temperature and high-pressure gaseous refrigerant discharged from the compressor 5 passes through the flow path switching device 6 and flows into the indoor heat exchanger 9 acting as a condenser. Heat exchanges with and condenses and liquefies. At this time, the room air is warmed and the room is heated. The condensed refrigerant in the liquid state flows into the expansion section 8 and is expanded and decompressed in the expansion section 8 to become a low-temperature, low-pressure gas-liquid two-phase refrigerant. Then, the refrigerant in the gas-liquid two-phase state flows into the outdoor heat exchanger 7 acting as an evaporator, where the refrigerant exchanges heat with outdoor air to evaporate and gasify. The evaporated low-temperature and low-pressure gaseous refrigerant passes through the flow path switching device 6 and is sucked into the compressor 5.

  FIG. 2 is a block diagram showing control unit 10 of air-conditioning apparatus 1 according to Embodiment 1 of the present invention. Next, the control unit 10 will be described in detail. As shown in FIG. 2, the control unit 10 has a setting unit 21 and a compression control unit 24. The setting unit 21 sets the target temperature range of the refrigerant flowing through the indoor heat exchanger 9 based on the indoor set temperature Tset set by the remote controller 4. The setting unit 21 includes an upper limit setting unit 22 and a lower limit setting unit 23. The upper limit setting unit 22 increases the upper limit of the target temperature as the indoor set temperature Tset is higher. The lower limit setting means 23 lowers the lower limit of the target temperature as the indoor set temperature Tset is lower.

  FIG. 3 is a graph showing a range of the target temperature of the evaporation temperature Te in the first embodiment of the present invention. Here, the range of the target temperature of the evaporation temperature Te of the refrigerant flowing through the indoor heat exchanger 9 acting as the evaporator during the cooling operation will be described. When there is a demand for cooling, as shown in FIG. 3, for example, when the outdoor temperature is high, the indoor set temperature Tset tends to be set low. On the other hand, when the outdoor temperature is low, the indoor set temperature Tset tends to be set high in order to suppress excessive cooling. At this time, the upper limit setting means 22 sets the target temperature upper limit Temax higher when the indoor set temperature Tset is higher than when the indoor set temperature Tset is lower. Thereby, it is possible to suppress the evaporation temperature Te from approaching the set temperature Tset too much. Therefore, it is possible to prevent the cooling capacity from being insufficient. The lower limit setting means 23 sets the lower limit Temin of the target temperature higher when the indoor set temperature Tset is higher than when the indoor set temperature Tset is lower. Thereby, it is possible to suppress the evaporation temperature Te from dropping too much. Therefore, excessive cooling can be suppressed.

  An example in which the set temperature Tset is 22 ° will be described. The upper limit setting means 22 sets the upper limit Temax of the target temperature to Temax = 22-A ° C. Here, A is a predetermined temperature. The lower limit setting means 23 sets the lower limit Temin of the target temperature to Temin = 22-ABC. Here, B is a predetermined temperature.

  FIG. 4 is a graph showing a target temperature range of the condensing temperature Tc according to the first embodiment of the present invention. Here, the range of the target temperature of the condensing temperature Tc of the refrigerant flowing through the indoor heat exchanger 9 acting as a condenser during the heating operation will be described. When there is a demand for heating, as shown in FIG. 4, for example, when the outdoor temperature is low, the indoor set temperature Tset tends to be set high. On the other hand, when the outdoor temperature is high, the indoor set temperature Tset tends to be set low in order to suppress excessive heating. At this time, the lower limit setting means 23 lowers the lower limit Tcmin of the target temperature when the indoor set temperature Tset is lower than when it is higher. Thereby, it is possible to suppress the condensation temperature Tc from approaching the set temperature Tset too much. Therefore, shortage of the heating capacity can be suppressed. The upper limit setting unit 22 lowers the target temperature upper limit Tcmax when the indoor set temperature Tset is lower than when the indoor set temperature Tset is higher. Thereby, it is possible to suppress the condensation temperature Tc from rising too high. Therefore, excessive heating can be suppressed.

  An example in which the set temperature Tset is 22 ° will be described. The lower limit setting means 23 sets the lower limit Tcmin of the target temperature to Tcmin = 22 + A ° C. Here, A is a predetermined temperature. The upper limit setting means 22 sets the upper limit Tcmax of the target temperature to Tcmax = 22 + A + B ° C. Here, B is a predetermined temperature.

  The compression control means 24 controls the compressor 5 so that the temperature of the refrigerant detected by the indoor temperature detection unit 13 falls within the range of the target temperature set by the setting means 21. The compression control unit 24 increases the frequency of the compressor 5 when the detected temperature of the refrigerant exceeds the upper limit of the target temperature during the cooling operation. As a result, the pressure difference between the suction side and the discharge side of the compressor 5 increases, so that the evaporation temperature Te decreases. In addition, the compression control unit 24 decreases the frequency of the compressor 5 when the detected temperature of the refrigerant is lower than the lower limit of the target temperature during the cooling operation. As a result, the pressure difference between the suction side and the discharge side of the compressor 5 becomes small, and the evaporation temperature Te rises.

  The compression control unit 24 increases the frequency of the compressor 5 when the detected temperature of the refrigerant falls below the lower limit of the target temperature during the heating operation. As a result, the pressure difference between the suction side and the discharge side of the compressor 5 increases, so that the condensation temperature Tc increases. Further, during the heating operation, the compression control unit 24 decreases the frequency of the compressor 5 when the detected temperature of the refrigerant exceeds the upper limit of the target temperature. As a result, the pressure difference between the suction side and the discharge side of the compressor 5 becomes smaller, so that the condensation temperature Tc decreases.

  FIG. 5 is a flowchart illustrating an operation of the air-conditioning apparatus 1 according to Embodiment 1 of the present invention. Next, the operation of the air conditioner 1 will be described. As shown in FIG. 5, first, the indoor set temperature Tset is set by the remote controller 4 (step ST1). Next, the upper limit value of the target temperature is set by the upper limit setting means 22 (step ST2). Further, the lower limit value of the target temperature is set by the lower limit setting means 23 (step ST3). Then, the frequency of the compressor 5 is changed (step ST4). At this time, it is determined whether or not the temperature detected by the room temperature detection unit falls within the target temperature range (step ST5). When the detected temperature is not within the target temperature range (No in step ST5), the process returns to step ST4, and the change of the frequency of the compressor 5 is continued. On the other hand, if the detected temperature falls within the target temperature range (Yes in step ST5), the control ends.

  According to the first embodiment, the target temperature range is set based on the indoor set temperature Tset, and the compressor 5 is controlled so as to fall within the set target temperature range. Therefore, regardless of the outdoor temperature, the difference between the temperature of the refrigerant flowing through the indoor heat exchanger 9 and the indoor set temperature Tset can be made constant. Therefore, the cooling operation or the heating operation that is sufficient for the user is performed. Thereby, comfortable air conditioning according to the user's request can be realized.

Embodiment 2 FIG.
FIG. 6 is a block diagram showing control unit 110 of air-conditioning apparatus 100 according to Embodiment 2 of the present invention. The second embodiment is different from the first embodiment in that the control unit 110 includes a release unit 125. In the second embodiment, the same portions as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. The description will focus on differences from the first embodiment.

  As shown in FIG. 6, the control unit 110 has a release unit 125. The canceling unit 125 cancels the setting of the target temperature range by the setting unit 21 when a person is not detected by the person detecting unit 14. Here, the control of setting the target temperature range based on the set temperature Tset by the setting means 21 is referred to as a range setting mode. Also, unlike the range setting mode, control that realizes more energy saving and improved cooling and heating capacity in consideration of the outdoor temperature is referred to as a normal mode. When the range setting mode is being executed, the release unit 125 continues the range setting mode when a person is detected, and releases the range setting mode and shifts to the normal mode when no person is detected. When there is a person in the room, the range setting mode is executed in order to prioritize that the person spends comfortably. On the other hand, when there is no person in the room, the normal mode in consideration of the outdoor temperature is executed in order to prioritize energy saving and improvement in cooling and heating capacity.

  FIG. 7 is a flowchart illustrating an operation of the air-conditioning apparatus 100 according to Embodiment 2 of the present invention. Next, the operation of the air conditioner 100 will be described. As shown in FIG. 7, when the range setting mode is being executed, the human detection unit 14 operates (step ST11), and it is determined whether a human has been detected (step ST12). When a person is detected (Yes in step ST12), the range setting mode is continued (step ST13). On the other hand, when no person is detected (No in step ST12), the range setting mode is canceled and the mode is shifted to the normal mode (step ST14).

  According to the second embodiment, when there is a person in the room, the comfort of the person is prioritized, and when there is no person in the room, energy saving and cooling / heating capability can be prioritized. Therefore, in addition to the effects of the first embodiment, it is possible to achieve both comfort, energy saving, and improvement in cooling and heating capacity.

  1 air conditioner, 2 outdoor units, 3 indoor units, 4 remote controllers, 5 compressors, 6 flow switching devices, 7 outdoor heat exchangers, 8 expansion units, 9 indoor heat exchangers, 10 control units, 11 outdoor control units , 12 indoor control device, 13 indoor temperature detecting section, 14 person detecting section, 21 setting means, 22 upper limit setting means, 23 lower limit setting means, 24 compression control means, 100 air conditioner, 110 control section, 125 release means.

The air conditioner according to the present invention includes a refrigerant circuit in which a compressor, an outdoor heat exchanger, an expansion unit, and an indoor heat exchanger are connected by piping, a refrigerant circuit, and a temperature of the refrigerant flowing in the indoor heat exchanger. comprising an inner temperature detection unit, a control unit for controlling the compressor, a control unit, the range of the target temperature of the refrigerant flowing into the chamber a heat exchanger, having a predetermined temperature difference with respect to the indoor set temperature setting means for setting, as the temperature of the refrigerant detected by the indoor temperature detector is, as fall within the scope of the set target temperature by setting means, having a compression control unit for controlling the compressor.

Claims (8)

A compressor, an outdoor heat exchanger, an expansion section, and an indoor heat exchanger connected by piping, and a refrigerant circuit through which a refrigerant flows;
An indoor-side temperature detector that detects the temperature of the refrigerant flowing through the indoor heat exchanger,
A control unit for controlling the compressor,
The control unit includes:
Setting means for setting a range of a target temperature of the refrigerant flowing through the indoor heat exchanger based on a set temperature in the room;
Compression control means for controlling the compressor such that the temperature of the refrigerant detected by the indoor temperature detecting section falls within the range of the target temperature set by the setting means. The setting means,
The air conditioner according to claim 1, further comprising an upper limit setting unit that lowers an upper limit value of the target temperature as the indoor set temperature is lower. If cooling operation is being performed,
The compression control means,
The air conditioner according to claim 2, wherein the frequency of the compressor is increased when a temperature of the refrigerant detected by the indoor side temperature detection unit exceeds an upper limit set by the upper limit setting unit. If heating operation is being performed,
The compression control means,
4. The air conditioner according to claim 2, wherein when the temperature of the refrigerant detected by the indoor-side temperature detection unit exceeds an upper limit set by the upper limit setting unit, the frequency of the compressor is reduced. 5. apparatus. The setting means,
The air conditioner according to any one of claims 1 to 4, further comprising lower limit setting means for increasing a lower limit value of the target temperature as the indoor set temperature is higher. If cooling operation is being performed,
The compression control means,
The air conditioner according to claim 5, wherein the frequency of the compressor is reduced when a temperature of the refrigerant detected by the indoor-side temperature detection unit falls below a lower limit set by the lower limit setting unit. If heating operation is being performed,
The compression control means,
7. The air conditioner according to claim 5, wherein when the temperature of the refrigerant detected by the indoor-side temperature detection unit falls below a lower limit set by the lower limit setting unit, the frequency of the compressor is increased. 8. apparatus. It further includes a person detection unit that detects the presence or absence of a person in the room,
The control unit includes:
The air conditioner according to any one of claims 1 to 7, further comprising a release unit configured to release the setting of the target temperature range by the setting unit when a person has not been detected by the person detection unit.

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