JP2021124228A - Refrigeration cycle device - Google Patents

Abstract

To provide a refrigeration cycle device that can suppress the occurrence of a situation where a rise time shortens excessively with respect to a target time and consumption power of a compressor increases, while suppressing the occurrence of a situation where the rise time exceeds the target time.SOLUTION: An air conditioner 100 comprises a compressor 12 and a controller 90. The controller controls the current of the compressor so that it is equal to or less than a current threshold value It. The controller changes the current threshold based on the time during which the compressor is running at the current threshold.SELECTED DRAWING: Figure 3

Description

Regarding refrigeration cycle equipment.

Conventionally, as in Patent Document 1 (Japanese Unexamined Patent Publication No. 2009-243814), a refrigeration cycle apparatus has been known in which an upper limit value of a current supplied to a compressor is set and the current used in the compressor is controlled to the upper limit value or less. There is. Further, in Patent Document 1 (Japanese Unexamined Patent Publication No. 2009-243814), an upper limit value of a current is manually set from a plurality of candidates, or an upper limit value of a current is set based on a temperature difference between a suction temperature and a target temperature. Is disclosed to control the current used in the compressor below the set upper limit.

However, when manually setting the upper limit of the current in advance, if the upper limit to be set is too small, the rise time at the start of operation of the refrigeration cycle device (the temperature to be adjusted from the start of operation reaches the target temperature). Time to do) may be too long. On the contrary, if the upper limit to be set is too large, the start-up time at the start of operation of the refrigeration cycle device will be short, but the compressor may be operating in a state of poor energy efficiency, and the refrigeration cycle device may be operated. Energy consumption at the start of operation may increase

The refrigeration cycle device of the first aspect includes a compressor and a control unit. The control unit controls the current of the compressor so that it is equal to or less than the current threshold value. The control unit changes the current threshold value based on the time the compressor is operated at the current threshold value.

In the refrigeration cycle apparatus of the first aspect, the current threshold is changed according to the time when the compressor is operated at the current threshold. Therefore, in the refrigeration cycle device of the first aspect, the current threshold value is optimized to suppress the rise time of the refrigeration cycle device from becoming long, and the rise time becomes excessively short, so that the power consumption at the start of operation increases. It is possible to suppress the occurrence of such a situation.

The refrigeration cycle device of the second aspect is the refrigeration cycle device of the first aspect, and the control unit raises the current threshold value when the compressor is operated at the current threshold value longer than the first hour.

In the refrigeration cycle device of the second aspect, control is performed to raise the current threshold value when the compressor is operated at the current threshold value longer than the first hour, so that a situation occurs in which the rise time of the refrigeration cycle device becomes too long. Can be suppressed.

The refrigeration cycle apparatus of the third aspect is the refrigeration cycle apparatus of the second aspect, and the control unit raises the current threshold value when the time during which the compressor is continuously operated at the current threshold value is longer than the first hour.

In the refrigeration cycle device of the third aspect, control is performed to raise the current threshold value when the time during which the compressor is continuously operated at the current threshold value is longer than a predetermined time, so that this can be quickly performed when the current threshold value is too small. Is easy to improve.

The refrigeration cycle device of the fourth aspect is the refrigeration cycle device of the first aspect, and the control unit raises the current threshold value when the compressor is operated at the current threshold value longer than the first hour, and uses the current threshold value. The current threshold is lowered when the compressor is operated for less than the second hour.

In the refrigeration cycle apparatus of the fourth aspect, it is easy to quickly improve the rise time of the refrigeration cycle apparatus when the rise time of the refrigeration cycle apparatus becomes too long or the current threshold value is too small.

The refrigeration cycle device of the fifth aspect is the refrigeration cycle device of the fourth aspect, and the control unit raises the current threshold value when the time during which the compressor is continuously operated at the current threshold value is longer than the first hour. The current threshold is lowered when the integrated time during which the compressor is operated at the current threshold during the predetermined period is shorter than the second hour.

In the refrigeration cycle apparatus of the fifth aspect, it is easy to quickly improve the rise time of the refrigeration cycle apparatus when the rise time of the refrigeration cycle apparatus becomes too long or the current threshold value is too small.

The refrigeration cycle apparatus of the sixth aspect is the refrigeration cycle apparatus of the fifth aspect from the second aspect, and the control unit compresses the refrigeration cycle apparatus so as to start the operation of the refrigeration cycle apparatus one hour earlier than the set schedule. Control the machine.

In the refrigerating cycle apparatus of the sixth aspect, power consumption can be suppressed while operating so as to complete the start-up of the refrigerating cycle apparatus within the time of the precooling operation and the preheating operation during the scheduled operation.

The refrigeration cycle device of the seventh aspect is any of the refrigeration cycle devices of any of the first to third aspects, and the control unit has a second time in which the compressor is operated at the current threshold value during a predetermined period. If it is shorter, lower the current threshold.

In the refrigeration cycle apparatus of the seventh aspect, control is performed to lower the current threshold value when the integrated time in which the compressor is operated at the current threshold value is shorter than the second time in a predetermined period, so that the rise time of the refrigeration cycle apparatus is shortened. It is possible to suppress the occurrence of a situation in which excessive power consumption increases.

The refrigerating cycle device of the eighth aspect is any refrigerating cycle device of any of the first to seventh aspects, and the control unit sets the current threshold value to 1 of the design maximum value of the current of the compressor when the current threshold value is changed. Change ~ 4%.

In the refrigeration cycle device of the eighth aspect, it is possible to suppress the occurrence of a state in which the change in the current threshold value is not sufficient or a state in which the change in the current threshold value is too large and it is necessary to change the current threshold value in the opposite direction (hunting). be able to.

The refrigeration cycle device of the ninth aspect is any of the refrigeration cycle devices of the first to eighth aspects, and the control unit compresses the refrigeration cycle device with a predetermined initial value as a current threshold value when the power is turned on. Control the current of the machine so that it is below the current threshold.

Appropriate values of the current threshold vary, for example, between high load seasons and low load seasons. Therefore, when the refrigeration cycle device is not used for a long period of time and the use is resumed after a lapse of time from the previous use, the value that was appropriate as the current threshold value at the time of the previous use becomes the value of the current appropriate current threshold value. May be significantly different. Then, for example, when the current threshold value is excessively small with respect to an appropriate value at the time of resuming use, there is a possibility that the temperature of the temperature adjustment target does not reach the target temperature for a long time at the start of operation or the like.

On the other hand, in the refrigeration cycle device of the ninth aspect, a predetermined initial value is used as the current threshold value when the power is turned on. Therefore, if a somewhat large value is adopted as the initial value, it is possible to suppress the occurrence of a situation in which the temperature of the temperature adjustment target does not reach the target temperature for a long time at the start of operation or the like.

The refrigeration cycle device of the tenth aspect is any of the refrigeration cycle devices of the first to ninth aspects, and the control unit uses a predetermined initial value as a current threshold value when the refrigeration cycle device is first used. , Control the compressor current so that it is below the current threshold. The control unit changes the current threshold value to the initial value when the compressor is operated at the current threshold value longer than the third time.

In the refrigeration cycle apparatus of the tenth aspect, the current threshold value can be returned to the initial value when the compressor is operated for a long time at the current threshold value, in other words, when the value of the current threshold value is too small. Therefore, if a somewhat large value is adopted as the initial value, it is possible to suppress the occurrence of a situation in which the temperature of the temperature adjustment target does not reach the target temperature for a long time.

It is a schematic block diagram of the air conditioner which concerns on one Embodiment. It is a control block diagram of the air conditioner of FIG. This is an example of a flowchart of the first change processing of the current threshold value of the air conditioner of FIG. This is an example of a flowchart of the second change processing of the current threshold value of the air conditioner of FIG. It is an example of the flowchart of the 3rd change processing of the current threshold value of the air conditioner of FIG. It is an example of the flowchart of the 4th change processing of the current threshold value of the air conditioner of FIG. It is a figure which conceptually showed the relationship between the capacity and the coefficient of performance in the air conditioner of FIG. It is a figure which conceptually showed the example of the time change of the current and the current threshold value when the value of the set current threshold value is too low. It is a figure which conceptually showed the example of the time change of the current and the current threshold value when the value of the set current threshold value is too large.

Hereinafter, embodiments of the refrigeration cycle apparatus will be described with reference to the drawings.

(1) Overall Overview The outline of the air conditioner 100, which is an example of the refrigeration cycle apparatus, will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic configuration diagram of the air conditioner 100. FIG. 2 is a control block diagram of the air conditioner 100.

The air conditioner 100 is a device that performs a vapor compression refrigeration cycle to cool and heat the air-conditioned space. Although not limited, the air-conditioned space is, for example, an office or a commercial facility. In the present embodiment, the air conditioner 100 is a device capable of both cooling and heating the space to be air-conditioned. However, the air conditioner of the present disclosure is not limited to an air conditioner capable of both cooling and heating, and may be, for example, a device capable of only cooling. Further, the air conditioner 100 is only an example of a refrigerating cycle device, and the refrigerating cycle device may be another type of device such as a water heater or a floor heating device that performs a steam compression refrigeration cycle.

The air conditioner 100 mainly includes a heat source unit 10, a utilization unit 30, and a gas refrigerant communication pipe GP and a liquid refrigerant communication pipe LP that connect the heat source unit 10 and the utilization unit 30.

In the present embodiment, the air conditioner 100 includes three utilization units 30. However, the number of utilization units 30 is not limited to three, and may be one, two, or four or more.

The gas refrigerant connecting pipe GP and the liquid refrigerant connecting pipe LP are laid at the installation site of the air conditioner 100. The pipe diameter and pipe length of the gas-refrigerant connecting pipe GP and the liquid-refrigerant connecting pipe LP are selected according to the design specifications and the installation environment.

In the air conditioner 100, the heat source unit 10 and the utilization unit 30 are connected by a gas refrigerant connecting pipe GP and a liquid refrigerant connecting pipe LP to form a refrigerant circuit C. The refrigerant circuit C is filled with various refrigerants. The refrigerant circuit C includes a compressor 12 of the heat source unit 10, a heat source heat exchanger 16 and a first expansion valve 18, and a utilization heat exchanger 32 and a second expansion valve 34 of each utilization unit 30.

The controller 90, which includes the heat source unit 10, the utilization unit 30, the first control unit 22 of the heat source unit 10, and the second control unit 38 of the utilization unit 30, controls the operation of various devices of the air conditioner 100, and the like. Will be described in detail.

(2) Detailed configuration (2-1) Heat source unit The heat source unit 10 will be described.

The heat source unit 10 is installed, for example, on the rooftop, machine room, around the building, or the like of the building where the air conditioner 100 is installed.

The heat source unit 10 includes a compressor 12, a flow direction switching mechanism 14, a heat source heat exchanger 16, a first expansion valve 18, a first fan 20, a discharge pressure sensor 24, a first control unit 22, and a first. It mainly includes one closing valve 13a and a second closing valve 13b (see FIG. 1).

Further, the heat source unit 10 has a suction pipe 11a, a discharge pipe 11b, a first gas refrigerant pipe 11c, a liquid refrigerant pipe 11d, and a second gas refrigerant pipe 11e as refrigerant pipes (see FIG. 1). .. The suction pipe 11a connects the flow direction switching mechanism 14 and the suction side of the compressor 12. The discharge pipe 11b connects the discharge side of the compressor 12 and the flow direction switching mechanism 14. The first gas refrigerant pipe 11c connects the flow direction switching mechanism 14 and the gas side end of the heat source heat exchanger 16. The liquid refrigerant pipe 11d connects the liquid side end of the heat source heat exchanger 16 and the liquid refrigerant connecting pipe LP. A first closing valve 13a is provided at the connection portion between the liquid refrigerant pipe 11d and the liquid refrigerant connecting pipe LP. The first expansion valve 18 is provided in the liquid refrigerant pipe 11d. The second gas refrigerant pipe 11e connects the flow direction switching mechanism 14 and the gas refrigerant connecting pipe GP. A second closing valve 13b is provided at the connection portion between the second gas refrigerant pipe 11e and the gas refrigerant connecting pipe GP.

(2-1-1) Compressor The compressor 12 is a device that sucks in the low-pressure gas refrigerant in the refrigeration cycle, compresses it in a compression mechanism (not shown), and discharges the high-pressure gas refrigerant in the refrigeration cycle.

The compressor 12 is an inverter-controlled compressor.

The controller 90 described later, which controls the operation of the compressor 12, basically rotates the motor of the compressor 12 at a high speed when the air conditioning load is large, and rotates the motor of the compressor 12 at a low speed when the air conditioning load is small. Let me. In other words, the controller 90 basically controls the current i (current value) supplied to the motor of the compressor 12 when the air conditioning load is large, and the current i supplied to the motor of the compressor 12 when the air conditioning load is small. Is controlled to be small.

Further, the controller 90 controls the current i supplied to the motor of the compressor 12 so as to be equal to or less than the current threshold value It. Specifically, the controller 90 supplies a current i larger than the current threshold Itt to the motor of the compressor 12 in view of the capacity required of the air conditioner 100 (in other words, the air conditioning load processed by the air conditioner 100). Even if this is the case, the current i supplied to the motor of the compressor 12 is controlled to the current threshold It.

Here, the current threshold value It is a value equal to or less than the design maximum value Imax of the current of the compressor 12. Further, the current threshold value It is a value equal to or more than the design minimum value Imin of the current of the compressor 12. Preferably, the current threshold It is a value smaller than the design maximum value Imax of the current of the compressor 12, and a value larger than the design minimum value Imin of the current of the compressor 12.

The design maximum value Imax of the current here is a value of the current that can be supplied to the compressor 12 determined by the manufacturer of the air conditioner 100 or the like. For example, although not limited, the design maximum value Imax of the current is a value obtained by multiplying the rated current value of the compressor 12 or the rated current value of the compressor 12 by a predetermined safety factor. The design minimum value Imin of the current is the value of the minimum current supplied to the compressor 12 defined by the manufacturer of the air conditioner 100 or the like.

The reason why the controller 90 controls the current i of the compressor 12 so as to be equal to or less than the current threshold value It will be described with reference to FIG. 7. FIG. 7 is a conceptual graph showing the relationship between the capacity of the air conditioner 100 and the COP (coefficient of performance) of the air conditioner 100. As can be seen from FIG. 7, the COP of the air conditioner 100 has a relationship that it becomes maximum when the capacity is a predetermined value and gradually deteriorates as the capacity is made larger than the predetermined value.

By the way, the capacity of the air conditioner 100 basically increases as the current i supplied to the motor of the compressor 12 increases. Therefore, when the air conditioning load is large, it is better to increase the current i supplied to the motor of the compressor 12 in the target state (in the present embodiment, the temperature of the air conditioning target space of the air conditioner 100 becomes the target temperature). State) is easy to realize quickly. However, if the current i supplied to the motor of the compressor 12 is increased to increase the capacity of the air conditioner 100, the COP (coefficient of performance) of the air conditioner 100 deteriorates as shown in the graph of FIG. Therefore, in the air conditioner 100, in order to suppress the deterioration of the energy consumption rate, the controller 90 controls the current i supplied to the motor of the compressor 12 so as to be equal to or less than the current threshold value It.

The controller 90, which will be described later, appropriately changes the current threshold value It used for controlling the compressor 12. The change of the current threshold value It will be described later.

(2-1-2) Flow direction switching mechanism The flow direction switching mechanism 14 is a mechanism for switching the flow direction of the refrigerant in the refrigerant circuit C according to the operation mode (cooling operation mode / heating operation mode) of the air conditioner 100. The flow direction switching mechanism 14 is a four-way switching valve.

In the cooling operation mode, the flow direction switching mechanism 14 switches the flow direction of the refrigerant in the refrigerant circuit C so that the refrigerant discharged by the compressor 12 is sent to the heat source heat exchanger 16. Specifically, in the cooling operation mode, the flow direction switching mechanism 14 communicates the suction pipe 11a with the second gas refrigerant pipe 11e and the discharge pipe 11b with the first gas refrigerant pipe 11c (see the solid line in FIG. 1). ). In the cooling operation mode, the heat source heat exchanger 16 functions as a condenser, and the utilization heat exchanger 32 functions as an evaporator.

In the heating operation mode, the flow direction switching mechanism 14 switches the flow direction of the refrigerant in the refrigerant circuit C so that the refrigerant discharged by the compressor 12 is sent to the utilization heat exchanger 32. Specifically, in the heating operation mode, the flow direction switching mechanism 14 communicates the suction pipe 11a with the first gas refrigerant pipe 11c and the discharge pipe 11b with the second gas refrigerant pipe 11e (see the broken line in FIG. 1). ). In the heating operation mode, the heat source heat exchanger 16 functions as an evaporator, and the utilization heat exchanger 32 functions as a condenser.

The flow direction switching mechanism 14 may be realized without using the four-way switching valve. For example, the flow direction switching mechanism 14 may be configured by combining a plurality of solenoid valves and pipes so as to realize the switching of the flow direction of the refrigerant as described above.

(2-1-3) Heat Source Heat Exchanger The heat source heat exchanger 16 functions as a refrigerant condenser during the cooling operation and as a refrigerant evaporator during the heating operation. Although not limited, the heat source heat exchanger 16 is, for example, a fin-and-tube type heat exchanger having a plurality of heat transfer tubes and a plurality of heat transfer fins.

(2-1-4) First Expansion Valve The first expansion valve 18 is a mechanism for reducing the pressure of the refrigerant and adjusting the flow rate of the refrigerant. In the present embodiment, the first expansion valve 18 is an electronic expansion valve whose opening degree can be adjusted. The opening degree of the first expansion valve 18 is appropriately adjusted according to the operating conditions. The first expansion valve 18 is not limited to the electronic expansion valve, and may be another type of expansion valve such as a temperature automatic expansion valve.

(2-1-5) First fan The first fan 20 is air that flows into the heat source unit 10 from the outside of the heat source unit 10, passes through the heat source heat exchanger 16, and then flows out to the outside of the heat source unit 10. A blower that produces a flow. The first fan 20 is, for example, an inverter control type fan.

(2-1-6) First Closing Valve and Second Closing Valve The first closing valve 13a is a valve provided at a connection portion between the liquid refrigerant pipe 11d and the liquid refrigerant connecting pipe LP. The second closing valve 13b is a valve provided at a connection portion between the second gas refrigerant pipe 11e and the gas refrigerant connecting pipe GP. The first closing valve 13a and the second closing valve 13b are manual valves. The first closing valve 13a and the second closing valve 13b are open when the air conditioner 100 is used.

(2-1-7) Discharge pressure sensor The discharge pressure sensor 24 is a sensor for measuring the discharge pressure Pd of the compressor 12. In the present embodiment, the discharge pressure sensor 24 is a pressure sensor provided on the discharge pipe 11b.

The sensor for measuring the discharge pressure Pd of the compressor 12 is not limited to the pressure sensor. For example, the sensor for measuring the discharge pressure Pd of the compressor 12 may be a temperature sensor for measuring the condensation temperature in the refrigeration cycle. For example, during the heating operation, the temperature sensor provided in the utilization heat exchanger 32 that functions as a condenser may be used as a sensor for measuring the discharge pressure Pd of the compressor 12. The controller 90, which will be described later, can calculate the discharge pressure Pd of the compressor 12 from the condensation temperature by storing the relational expression between the condensation temperature and the pressure in the storage unit of the controller 90.

(2-1-8) First Control Unit The first control unit 22 controls the operation of various devices of the heat source unit 10. The first control unit 22 mainly includes a microcontroller unit (MCU) and various electric circuits and electronic circuits (not shown). The MCU includes a CPU, a memory, an I / O interface, and the like. Various programs for execution by the CPU of the MCU are stored in the memory of the MCU. The various functions of the first control unit 22 do not have to be realized by software, and may be realized by hardware or may be realized by cooperation between hardware and software.

The first control unit 22 is electrically connected to various devices of the heat source unit 10 including the compressor 12, the flow direction switching mechanism 14, the first expansion valve 18, and the first fan 20 (see FIG. 1). Further, the first control unit 22 is electrically connected to various sensors provided in the heat source unit 10 including the discharge pressure sensor 24. Although not limited, the sensors provided in the heat source unit 10 include a temperature sensor provided in the discharge pipe 11b, a temperature sensor and a pressure sensor provided in the suction pipe 11a, a heat source heat exchanger 16 and a liquid refrigerant pipe 11d. It may include a temperature sensor, a temperature sensor for measuring the temperature of the heat source air, and the like. However, the heat source unit 10 does not have to have all of these sensors.

The first control unit 22 is communicably connected to the centralized operation device 50 by a communication line. The centralized operation device 50 is a device capable of centrally operating the operation and stop of the heat source unit 10 and the plurality of utilization units 30. Further, the centralized operation device 50 is a device capable of setting scheduled operation of the air conditioner 100.

The first control unit 22 is connected to the second control unit 38 of the plurality of utilization units 30 by a communication line. The first control unit 22 and the second control unit 38 exchange various signals via a communication line. The first control unit 22 and the second control unit 38 cooperate with each other to function as a controller 90 that controls the operation of the air conditioner 100. The function of the controller 90 will be described later.

(2-2) Utilization Unit The utilization unit 30 will be described.

The utilization unit 30 blows out air that has exchanged heat with the refrigerant flowing through the utilization heat exchanger 32 into the air-conditioned space. The utilization unit 30 is, for example, a ceiling-mounted type installed on the ceiling of the air-conditioned space. The utilization unit 30 of the present embodiment is a ceiling-embedded air conditioner indoor unit. The ceiling-embedded air-conditioning indoor unit includes a ceiling cassette type air-conditioning indoor unit in which at least a part of the air-conditioning indoor unit is arranged in the ceiling space, and a duct in which all of the air-conditioning indoor units are arranged in the ceiling space. Includes duct-connected air-conditioning indoor units to be connected. The type of the utilization unit 30 is not limited to the ceiling-embedded type, and may be a ceiling-suspended type. Further, the type of the utilization unit 30 may be other than the ceiling-mounted type such as a wall-mounted type or a floor-standing type.

As shown in FIG. 1, the utilization unit 30 mainly includes a utilization heat exchanger 32, a second expansion valve 34, a second fan 36, a suction temperature sensor 35, and a second control unit 38.

Further, the utilization unit 30 has a liquid refrigerant pipe 37a and a gas refrigerant pipe 37b connected to the utilization heat exchanger 32 as a refrigerant pipe (see FIG. 1). The liquid refrigerant pipe 37a connects the liquid refrigerant connecting pipe LP and the liquid side of the utilization heat exchanger 32. The liquid refrigerant pipe 37a is provided with a second expansion valve 34. The gas refrigerant pipe 37b connects the gas refrigerant connecting pipe GP and the gas side of the utilization heat exchanger 32.

(2-2-1) Indoor heat exchanger In the utilization heat exchanger 32, heat exchange is performed between the refrigerant flowing through the utilization heat exchanger 32 and the air. The utilization heat exchanger 32 is, for example, a fin-and-tube type heat exchanger having a plurality of heat transfer tubes and a plurality of heat transfer fins, without limitation.

As shown in FIG. 1, a liquid refrigerant pipe 37a is connected to one end of the utilization heat exchanger 32. As shown in FIG. 1, a gas refrigerant pipe 37b is connected to the other end of the utilization heat exchanger 32. During the cooling operation, the refrigerant flows into the utilization heat exchanger 32 from the liquid refrigerant pipe 37a, and the refrigerant that has exchanged heat with air in the utilization heat exchanger 32 flows out from the gas refrigerant pipe 37b. During the heating operation, the refrigerant flows into the utilization heat exchanger 32 from the gas refrigerant pipe 37b, and the refrigerant that has exchanged heat with the air in the utilization heat exchanger 32 flows out from the liquid refrigerant pipe 37a.

The utilization heat exchanger 32 functions as a refrigerant evaporator during the cooling operation and as a refrigerant condenser during the heating operation.

(2-2-2) Second Expansion Valve The second expansion valve 34 is a mechanism for reducing the pressure of the refrigerant and adjusting the flow rate of the refrigerant. In the present embodiment, the second expansion valve 34 is an electronic expansion valve whose opening degree can be adjusted. The opening degree of the second expansion valve 34 is appropriately adjusted according to the operating condition. The second expansion valve 34 is not limited to the electronic expansion valve, and may be another type of expansion valve such as a temperature automatic expansion valve.

(2-2-3) 2nd fan The 2nd fan 36 is a blower that flows into the utilization unit 30 from the air conditioning target space, passes through the utilization heat exchanger 32, and then generates an air flow that blows out to the air conditioning target space. Is. The first fan 20 is, for example, an inverter control type fan.

(2-2-4) Suction temperature sensor The suction temperature sensor 35 is a sensor that measures the temperature of air (suction temperature Ti) taken into the utilization unit 30 from the air-conditioned space. In other words, the suction temperature sensor 35 is a sensor that measures the temperature of the air-conditioned space.

(2-2-5) Second Control Unit The second control unit 38 controls the operation of various devices of the utilization unit 30. The second control unit 38 includes a microcontroller unit (MCU) and various electric circuits and electronic circuits (not shown). The MCU includes a CPU, a memory, an I / O interface, and the like. Various programs for execution by the CPU of the MCU are stored in the memory of the MCU. The various functions of the second control unit 38 do not have to be realized by software, and may be realized by hardware or may be realized by cooperation between hardware and software.

The second control unit 38 is electrically connected to various devices of the utilization unit 30, including the second expansion valve 34 and the second fan 36 (see FIG. 1). Further, the second control unit 38 is electrically connected to the suction temperature sensor 35. Further, the second control unit 38 is electrically connected to a sensor (not shown) provided in the utilization unit 30. Although not limited to the sensors, the sensors (not shown) include a utilization heat exchanger 32, a temperature sensor provided on the liquid refrigerant pipe 37a, and the like.

The second control unit 38 is communicably connected to the centralized operation device 50 by a communication line. Further, the second control unit 38 of each utilization unit 30 is for operating the air conditioner 100 (not shown), which can operate and stop the utilization unit 30 and set a target temperature by means of a communication line. It is connected so that it can communicate with the remote control.

The second control unit 38 of each utilization unit 30 is connected to the first control unit 22 of the heat source unit 10 by a communication line. The first control unit 22 and the second control unit 38 cooperate with each other to function as a controller 90 that controls the operation of the air conditioner 100.

(2-3) Controller The controller 90 will be described. Note that some or all of the various functions of the controller 90 described below may be executed by a control device provided separately from the first control unit 22 and the second control unit 38.

The controller 90 has a storage unit (not shown) that stores a program for execution by the CPU of the controller 90 and various information used for controlling the operation of the air conditioner 100.

The CPU of the controller 90 executes a program stored in the storage unit, so that the controller 90 controls the operation of each part of the air conditioner 100 during the cooling operation and the heating operation.

For example, the controller 90 controls the operation of the flow direction switching mechanism 14 so that the heat source heat exchanger 16 functions as a refrigerant condenser and the utilization heat exchanger 32 functions as a refrigerant evaporator during the cooling operation. Further, the controller 90 controls the operation of the flow direction switching mechanism 14 so that the heat source heat exchanger 16 functions as a refrigerant evaporator and the utilization heat exchanger 32 functions as a refrigerant condenser during the heating operation.

Further, the controller 90 controls the rotation speed of the motor of the compressor 12 according to the air conditioning load during the cooling operation and the heating operation. In other words, the controller 90 controls the current i supplied to the motor of the compressor 12 during the cooling operation and the heating operation. The controller 90 largely controls the current i supplied to the motor of the compressor 12 when the air conditioning load is large. On the other hand, the controller 90 controls the current i supplied to the motor of the compressor 12 to be small when the air conditioning load is small. The time when the air conditioning load is large is, for example, when the number of operating units 30 is large and the difference between the actual temperature of the air conditioning target space and the target temperature (set temperature) is large. The time when the air conditioning load is small is, for example, when the number of operating units 30 is small and the difference between the actual temperature of the air conditioning target space and the target temperature is small. As described above, the controller 90 controls the current i supplied to the motor of the compressor 12 so as to be equal to or less than the current threshold value It stored in the storage unit. Depends on controller 90. The change of the current threshold value It will be described later.

Further, the controller 90 is a motor of the first fan 20 and the second fan 36 based on the measured values of various sensors (temperature sensor and pressure sensor), the target temperature of the air conditioning target space, and the like during the cooling operation and the heating operation. The number of rotations and the opening degrees of the first expansion valve 18 and the second expansion valve 34 are adjusted. It should be noted that various control modes are used for controlling the rotation speeds of the motors of the first fan 20 and the second fan 36 and the opening degrees of the first expansion valve 18 and the second expansion valve 34 during the cooling operation and the heating operation. Is generally known, and therefore, the description thereof is omitted here in order to avoid complicated explanation.

(3) Current Threshold Change Process The current threshold It change process by the controller 90 will be described.

Before explaining the change process, the reason for performing the change process of the current threshold value It will be described with a specific example.

Here, a case where the controller 90 performs the cooling operation and the heating operation of the air conditioner 100 based on the schedule operation setting input to the centralized operation device 50 will be described as an example. In the air conditioner 100 that performs the scheduled operation, the controller 90 starts the operation of the heat source unit 10 and the plurality of utilization units 30 at the operation start time of the scheduled operation set by using the centralized operation device 50. Further, the controller 90 ends the operation of the heat source unit 10 and the plurality of utilization units 30 at the operation end time of the scheduled operation set by using the centralized operation device 50.

The operation start time of the scheduled operation is set as follows, for example. For example, assume that the air conditioner 100 is installed in an office building. In this case, a time earlier than the time when the person working in the office building starts working by a predetermined time (for example, 15 minutes, but not limited to) is set as the operation start time of the scheduled operation.

For example, when the user sets a time (schedule) for the centralized operation device 50 to start using the air-conditioned space, the controller 90 starts the operation of the air-conditioned device 100 earlier than the set schedule by a predetermined time. In other words, when the user sets the time when the user starts using the air-conditioned space for the centralized operation device 50, the controller 90 sets a time earlier than the set time by a predetermined time as the operation start time of the scheduled operation. do.

Alternatively, the centralized operation device 50 may be directly input by the user to the operation start time of the scheduled operation, which is a predetermined time earlier than the time when the air-conditioned space is started to be used.

In the scheduled operation, the reason why the air conditioner 100 starts the operation earlier than the time when the person starts to use the air-conditioned space (in the above example, the work start time) is for precooling and preheating. Here, precooling is an air-conditioning target that rises while the operation of the air-conditioning device 100 is stopped so that the temperature of the air-conditioning target space is adjusted to the target temperature at the time when a person actually uses the air-conditioning target space. It means cooling operation to lower the temperature of the space. Preheating is the temperature of the air-conditioned space that is decreasing during the shutdown of the air-conditioning device 100 so that the temperature of the air-conditioned space is adjusted to the target temperature at the time when a person actually uses the air-conditioned space. It means heating operation to raise.

In the air conditioner 100 that performs scheduled operation, the air conditioning load during precooling and preheating is particularly large as compared with that after precooling and preheating. This is because the air conditioner 100 is normally stopped from the operation end time of the scheduled operation to the operation start time of the next scheduled operation, so that the temperature of the air conditioning target space and the target temperature are set at the operation start time of the scheduled operation. This is because is relatively large and easily deviates.

By the way, in precooling and preheating, it is desired that the temperature of the air-conditioned space reaches the target temperature at the time when a person starts using the air-conditioned space. From such a viewpoint, it is preferable that the motor of the compressor 12 is supplied with the current i as large as possible. In other words, the current threshold It is preferably set to a value as large as possible. However, if a large value is adopted for the current threshold value It and the capacity of the air conditioner 100 is increased too much, the air conditioner 100 may be operated under the condition of poor COP as shown in FIG. 7.

On the other hand, from the viewpoint of energy saving, it is preferable that the value of the current i supplied to the motor of the compressor 12 is limited to a range in which the COP can be maintained relatively high. In other words, the current threshold It is preferably set to a relatively small value. However, in this case, since the capacity of the air conditioner 100 is suppressed to a low level, the temperature of the air conditioner target space may not reach the target temperature even when it is time for a person to start using the air conditioner target space. obtain. In this case, the comfort of the user who uses the air-conditioned space may be reduced. If precooling and preheating are started sufficiently earlier than the time when a person starts using the air-conditioned space, there is a possibility that such a situation can be avoided even if a relatively small value is set for the current threshold value It. be. However, in this case, the cooling operation and the heating operation of the air-conditioned space where no one is present are performed for a long time, which is not preferable from the viewpoint of energy saving.

Therefore, in the air conditioner 100, the temperature of the air-conditioned space can be adjusted to the target temperature at the time when a person starts using the air-conditioned space without taking an excessively long precooling time, and the energy consumption can be increased. It is desired that the compressor 12 is operated under suppressable conditions. In order to realize this, in the air conditioner 100, the controller 90 performs a process of changing the current threshold value It for adjusting the current threshold value It to an appropriate value.

The process of changing the current threshold value It by the controller 90 will be described below.

The controller 90 controls the current i of the compressor 12 so as to be equal to or less than the current threshold value It stored in the storage unit of the controller 90. Therefore, the controller 90 changes the current threshold value It to be used by rewriting the value of the current threshold value It stored in the storage unit.

<Setting of current threshold value when power is turned on for air conditioner 100>
First, the setting of the current threshold value It when the power is turned on for the air conditioner 100 will be described.

When the power of the air conditioner 100 is turned on, the controller 90 sets the current threshold value It stored in the storage unit to a predetermined initial value I ₀ . In other words, when the power is turned on to the air conditioner 100, the controller 90 controls the current i of the compressor 12 to be equal to or less than the current threshold value It (initial value I _{0) with a predetermined initial value I 0 as the current threshold value It.} .. The time when the power is turned on for the air conditioner 100 includes the time when the power is turned on for the first time after the air conditioner 100 is installed in the building. Further, when the power is turned on to the air conditioner 100, for example, it includes a case where the breaker of the distribution board that supplies power to the air conditioner 100 is once turned off and then turned on again.

The initial value I ₀ is preferably a relatively large value. Although not limited to this, for the initial value I ₀ , for example, a value of 80 to 100% of the design maximum value Imax is used. By using such a relatively large initial value I ₀ , for example, when the air conditioner 100 is operated for the first time after being installed, or when a long period of time has passed since the previous air conditioner 100 was operated, the air conditioning target space can be used. It is easy to suppress the occurrence of a state in which the temperature does not reach the target temperature forever.

The current threshold value It stored in the storage unit at the start of operation of the air conditioner 100 may be used as it is, except when the power of the air conditioner 100 is turned on.

<Current threshold change processing>
The controller 90 executes the following four types of current threshold value It change processes (referred to as first change process to fourth change process) in parallel.

By performing the first to fourth change processes of the current threshold value It and optimizing the current threshold value It, for example, the rise time of the air conditioner 100 is suppressed while suppressing the occurrence of a situation in which the rise time exceeds the target time. It is possible to suppress the occurrence of a situation in which the power consumption of the compressor increases due to being excessively short with respect to the target time. To give a specific example, the precooling and preheating time in scheduled operation is optimized, and the temperature of the air conditioning target space does not reach the target temperature even when the use start time of the air conditioning target space is reached, and the precooling and preheating time. Is excessively shortened, and it is possible to avoid a situation in which the air conditioner 100 is operated under a bad condition of COP in which the capacity becomes higher than necessary.

As a premise of the change processing of the current threshold value It, the controller 90 continuously monitors the value of the current i supplied to the motor of the compressor 12.

(A) First change process of the current threshold value The first change process of the current threshold value It is generally described when the current i of the compressor 12 is operated at the current threshold value It longer than the first time T1. It is a process of increasing the value of It. The first change process of the current threshold value It will be described with reference to the flowchart of FIG.

As a premise of the first change processing of the current threshold value It, the controller 90 measures the time for which the compressor 12 is continuously operated at the current threshold value It.

The time during which the compressor 12 is operated at the current threshold value It means that the current i supplied to the motor of the compressor 12 may be controlled to be larger than the current threshold value It when viewed from the air conditioning load. Nevertheless, it means a state in which the current i is suppressed to the current threshold value It.

Further, in the present specification, the time during which the compressor 12 is continuously operated at the current threshold value It means the time during which the compressor 12 is continuously operated at the current threshold value It. For example, even if the current i supplied to the compressor 12 deviates from the current threshold value It for a short time (for example, about several seconds), if the current threshold value It is generally constant as a whole, the compressor 12 is defined as being continuously operated at the current threshold It.

The first change process of the current threshold value It of the controller 90 is started when the operation of the air conditioner 100 is started (step S1).

In the first change process, the controller 90 performs a process of determining whether or not the time during which the compressor 12 is continuously operated at the current threshold value It is equal to or longer than the first time T1 (step S2). Although not limited, the first time T1 is, for example, 15 minutes.

When the controller 90 sets a schedule (for example, the use start time of the air-conditioned space) for the centralized operation device 50, the controller 90 starts the operation of the air-conditioning device 100 earlier than the set schedule by a predetermined time. For the following reasons, it is preferable that the first time T1 is set to the above-mentioned predetermined time.

As described above, the air conditioning load during precooling and preheating performed when the scheduled operation is started tends to be larger than that at other timings. Therefore, the state in which the compressor 12 is continuously operated at the current threshold value It is particularly likely to occur during precooling or preheating. Therefore, when the scheduled operation is performed by changing the value of the current threshold It so that the time during which the compressor 12 is continuously operated at the current threshold It does not exceed the first time T1 by the first change process. In addition, the start-up of the refrigeration cycle device is likely to be completed within the time of the precooling operation or the preheating operation, in other words, by the start time of using the air-conditioned space.

For the same reason, even when the user directly inputs the operation start time of the scheduled operation to the centralized operation device 50, the time difference between the operation start time of the scheduled operation and the time when the air-conditioned space starts to be used and the first time It is preferable to match with T1.

If it is determined that the time during which the compressor 12 is operated at the current threshold value It is T1 or more for the first time, the process proceeds to step S3. On the other hand, if it is determined that the time during which the compressor 12 is operated at the current threshold value It is shorter than the first time T1, or if the compressor 12 is not operated at the current threshold value It, the process proceeds to step S6.

In step S3, the controller 90 determines whether or not the current threshold value It is the design maximum value Imax. If the current threshold value It is the design maximum value Imax, the process proceeds to step S4. On the other hand, if the current threshold value It is not the design maximum value Imax, the process proceeds to step S4.

In step S4, the controller 90 changes the current threshold It. Specifically, the controller 90 raises the current threshold value It by a predetermined value α.

The value of α is preferably 1 to 4% of the design maximum value Imax of the current of the compressor 12. In this embodiment, the value of α is 2% of the design maximum value Imax. By using such a value α, a state in which the change in the current threshold value It is not sufficient, or a state in which the change in the current threshold value It is too large and it is necessary to change the current threshold value It in the opposite direction (hunting). The occurrence can be suppressed.

The changed current threshold value It is stored in the storage unit. As a result, the controller 90 controls so that the current i of the compressor 12 becomes equal to or less than the changed current threshold value It.

Next, in step S5, the controller 90 resets the timekeeping for the first change process. In short, the controller 90 newly starts timing of the time during which the compressor 12 is continuously operated at the current threshold value It. Then, the process proceeds to step S6.

In step S6, it is determined whether or not the operation end condition of the air conditioner 100 is satisfied. The operation end condition of the air conditioner 100 is, for example, that the centralized operation device 50 is operated to stop the operation of the air conditioner 100. Further, the operation end condition of the air conditioner 100 is, for example, the operation end time of the scheduled operation. If the operation end condition is not satisfied, the process returns to step S2. When the operation termination condition is satisfied, the first change processing is terminated.

(B) Second change processing of the current threshold The second change processing of the current threshold It is generally described when the current i of the compressor 12 is operated at the current threshold It longer than the third time T3. This is a process of changing the value of It to the initial value I _0. The third time T3 is longer than the first time T1. Although not limited, for example, the first hour T1 is 15 minutes, while the third hour T3 is 45 minutes.

The second change process of the current threshold value It quickly eliminates the current threshold value It when the current threshold value It is set to a value significantly smaller than the optimum current threshold value It for some reason, and reduces the capacity of the air conditioner 100. The main purpose is to secure it.

Here, the second change process of the current threshold value It has priority over the first change process of the current threshold value It. In other words, here, when the condition that the current threshold value It is changed by the second change process and the condition that the current threshold value It is changed by the first change process are satisfied at the same time, the current threshold value by the second change process is satisfied. Only It changes are made.

The second change process of the current threshold value It will be described with reference to the flowchart of FIG.

As a premise of the second change processing of the current threshold value It, the controller 90 clocks the time during which the compressor 12 is continuously operated at the current threshold value It, separately from the time measurement for the first change processing of the current threshold value It. ing. Therefore, even if the time measurement is reset in step S5 of the first change process of the current threshold value It, the time measurement for the second change process of the current threshold value It may be continued. Specifically, when the current i supplied to the motor of the compressor 12 is the changed current threshold value It after the current threshold value It is raised in step S4 of the first change process of the current threshold value It, the current is current. The timing for the second change processing of the threshold value It is continued.

Immediately after the current threshold value It is raised, the current i supplied to the motor of the compressor 12 may fall below the current threshold value It for a short time (for example, about several seconds). However, even in such a case, the controller 90 determines that the current i of the compressor 12 is continuously operated at the current threshold value It, and continues the time counting for the second change processing of the current threshold value It. ..

The second change process of the current threshold value It of the controller 90 is started when the operation of the air conditioner 100 is started (step S11).

In the second change process, the controller 90 performs a process of determining whether or not the time during which the compressor 12 is continuously operated at the current threshold value It is T3 or more for the third time (step S12). If it is determined that the time during which the compressor 12 is operated at the current threshold value It is T3 or more for the third time, the process proceeds to step S13. On the other hand, if it is determined that the time during which the compressor 12 is operated at the current threshold value It is shorter than the third time T3, or if the compressor 12 is not operated at the current threshold value It, the process proceeds to step S15.

In step S13, the controller 90 changes the current threshold It. Specifically, the controller 90 changes the current threshold value It to the initial value I _0. The changed current threshold value It is stored in the storage unit. As a result, the controller 90 controls so that the current i of the compressor 12 becomes equal to or less than _{the changed current threshold value It (initial value I 0).}

In step S13, the effect of changing the current threshold value It to the initial value Io will be described.

In step S12, it is determined that the time during which the compressor 12 is continuously operated at the current threshold value It is T3 or more for the third time, that is, the compressor 12 is operated at the current threshold value It for a long time. This means that the temperature of the air-conditioned space has not reached the target temperature. In this case, it is assumed that the current threshold value It is too low. Therefore, in step S13, the controller 90 does not gradually increase the current threshold value It (for example, 1 to 4% of the design maximum value Imax of the current of the compressor 12), but increases it to the initial value I ₀ at once. There is. As a result, in cases where the air conditioner 100 has not been used for a long period of time and the season has changed since the last operation, or in an irregular environment (for example, when the temperature has changed significantly from the previous day). Even if there is, the temperature of the air-conditioned space can be quickly reached to the target temperature.

Next, in step S14, the controller 90 resets the timekeeping for the second change process. In short, the controller 90 newly starts timing of the time during which the compressor 12 is continuously operated at the current threshold value It. Then, the process proceeds to step S15.

In step S15, it is determined whether the operation end condition of the air conditioner 100 is satisfied. An example of the operation termination condition of the air conditioner 100 is as described above. If the operation end condition is not satisfied, the process returns to step S12. When the operation termination condition is satisfied, the second change processing is terminated.

(C) Third change process of the current threshold value The third change process of the current threshold value It is generally described in the case where the current i of the compressor 12 is operated at the current threshold value It longer than the second time T2. It is a process of lowering the value of It. The third change process of the current threshold value It will be described with reference to the flowchart of FIG.

As a premise of the third change process of the current threshold value It, the controller 90 measures the passage of a predetermined period with a timer. Further, as a premise of the third change processing of the current threshold value It, the controller 90 measures the integrated time in which the compressor 12 is operated at the current threshold value It.

In the third change process, the controller 90 repeatedly performs a process of determining whether or not a predetermined period has elapsed after starting the third change process at a predetermined timing (step S21). Although not limited, the predetermined period is, for example, 24 hours. Further, for example, when the controller 90 knows the operation start time of the scheduled operation (in other words, when the controller 90 knows the start time of precooling or preheating), the controller 90 takes a predetermined time from the scheduled operation start time. It may be determined in step S21 whether (for example, 1 hour) has elapsed. Further, for example, when the controller 90 knows the operation start time and the operation end time of the scheduled operation, the controller 90 may determine the period from the operation start time to the operation end time as a predetermined period. If it is determined in step S21 that the predetermined period has elapsed, the process proceeds to step S22.

In step S22, the controller 90 determines whether the integrated time during which the compressor 12 is operated at the current threshold value It is shorter than the second time T2. The second time T2 is, for example, 15 minutes, without limitation. If it is determined that the integrated time in which the compressor 12 is operated at the current threshold value It is less than the second time T2 during the predetermined period, the process proceeds to step S23. On the other hand, if it is determined that the integrated time in which the compressor 12 is operated at the current threshold value It during the predetermined period is T2 or more for the second time, the process proceeds to step S25.

In step S23, the controller 90 determines whether or not the current threshold value It is the design minimum value Imin. If the current threshold value It is the design minimum value Imin, the process proceeds to step S25. On the other hand, if the current threshold value It is not the design minimum value Imin, the process proceeds to step S24.

In step S24, the controller 90 changes the current threshold It. Specifically, the controller 90 lowers the current threshold value It by a predetermined value β. The value of β is preferably 1 to 4% of the design maximum value Imax of the current of the compressor 12. In this embodiment, the value of β is 2% of the design maximum value Imax. The value of β and the value of α in the first change process of the current threshold value It may be the same value or different values. The changed current threshold value It is stored in the storage unit. As a result, the controller 90 controls so that the current i of the compressor 12 becomes equal to or less than the changed current threshold value It.

Next, in step S25, the controller 90 resets the time counting of the integrated time for the third change process, and ends the third change process. When the predetermined period is 24 hours, the controller 90 immediately starts the next third change process after the end of the third change process, and the integrated time during which the compressor 12 is operated at the current threshold value It. Start a new timekeeping.

Here, it is assumed that the air conditioner 100 is operated every day. If there is a day when the air conditioner 100 is not operated even once in the predetermined period in step S21, the third change process of the current threshold value It may be prevented from being executed on that day.

(D) Fourth change process of current threshold value In the fourth change process of current threshold value It, generally speaking, even if the current i of the compressor 12 is operated at the current threshold value It, the temperature to be adjusted deviates from the target temperature. This is a process of increasing the value of the current threshold value It when the current threshold value is increased.

Although not limited, here, the fourth change process of the current threshold value It is prioritized over the first change process of the current threshold value It. In other words, here, when the condition that the current threshold value It is changed by the fourth change process and the condition that the current threshold value It is changed by the first change process are satisfied at the same time, the current threshold value by the fourth change process is satisfied. Only It changes are made. However, the present invention is not limited to this, and when the condition that the current threshold value It is changed by the fourth change process and the condition that the current threshold value It is changed by the first change process are satisfied at the same time, the first The change of the current threshold value It by the change process and the change of the current threshold value It by the fourth change process may be performed at the same time.

Specifically, the controller 90 is in a state where the temperature condition of the air-conditioned space subject to temperature control deviates from the target condition by the first reference or more when the compressor 12 is operated at the current threshold value It. When the first reference time Ts1 is continued, the current threshold value is increased by the first value γ1. Further, when the compressor 12 is operated at the current threshold value It, the state in which the temperature condition of the air-conditioned space deviates from the target condition by the second reference or more, which is smaller than the first reference, continues for the second reference time Ts2. If so, the current threshold is increased by the second value γ2, which is smaller than the first value γ1.

More specifically, in the controller 90, when the compressor 12 is operated at the current threshold value It, the difference between the suction temperature Ti in the utilization unit 30 as the temperature condition of the air-conditioned space and the target temperature as the target condition is When the state of deviation of the first temperature difference A or more as the first reference continues for the first reference time Ts1, the current threshold value It is increased by the first value γ1. Further, in the controller 90, when the compressor 12 is operated at the current threshold value It, the difference between the suction temperature Ti and the target temperature in the utilization unit 30 is smaller than the first temperature difference A, and the second temperature as a second reference. When the state of deviation of the difference B or more continues for the second reference time Ts2, the current threshold value It is increased by the second value γ2. The difference between the suction temperature Ti in the utilization unit 30 and the target temperature as the target condition is represented by (Ti-Ti) during the cooling operation and (Ti-Ti) during the heating operation. Will be done.

It should be noted that preferably, the controller 90 is in a state in which the difference between the suction temperature Ti and the target temperature as the target condition deviates from the first temperature difference A or more in the plurality of utilization units 30 during operation. When there is even one utilization unit 30 that continues the reference time Ts1, the current threshold value It is increased by the first value γ1. Further, preferably, the controller 90 is in a state in which the difference between the suction temperature Ti and the target temperature as the target condition deviates from the second temperature difference B or more in the plurality of utilization units 30 during operation. When there is even one utilization unit 30 that continues the reference time Ts2, the current threshold value It is increased by the second value γ2.

The fourth change process of the current threshold value It will be described with reference to the flowchart of FIG.

In the description of the fourth change process of the current threshold value It performed with reference to FIG. 6 below, the difference between the suction temperature Ti and the target temperature is the suction temperature Ti and the target temperature in the plurality of utilization units 30 during operation. It means the largest value in the difference with.

As a premise of the fourth change process of the current threshold value It, the controller 90 continuously monitors the time change of the difference between the suction temperature Ti and the target temperature.

The fourth change process of the current threshold value It of the controller 90 is started when the operation of the air conditioner 100 is started (step S41).

In the fourth change process of the current threshold value It, the controller 90 determines whether the compressor 12 is operated at the current threshold value It (step S42). If the compressor 12 is operated at the current threshold value It, the process proceeds to step S43. If the compressor 12 is not operated at the current threshold value It, the process proceeds to step S55.

In step S43, the controller 90 determines whether or not the state in which the difference between the suction temperature Ti and the target temperature deviates by the first temperature difference A or more continues for the first reference time Ts1. Although not limited, for example, the first temperature difference A is 5 ° C., and the first reference time Ts1 is 5 minutes. If the difference between the suction temperature Ti and the target temperature deviates from the first temperature difference A or more by the first reference time Ts1, the process proceeds to step S44, and the difference between the suction temperature Ti and the target temperature is the first. If the state of deviation of 1 temperature difference A or more does not continue for the first reference time Ts1, the process proceeds to step S49.

In step S44, the controller 90 determines whether or not the current threshold value It is the design maximum value Imax. If the current threshold value It is the design maximum value Imax, the process proceeds to step S55. On the other hand, if the current threshold value It is not the design maximum value Imax, the process proceeds to step S45.

In step S45, the controller 90 determines whether or not the air conditioner 100 is in the heating operation (whether the refrigeration cycle device is in the heating operation). If the heating operation is in progress, the process proceeds to step S46, and if the heating operation is not in progress, the process proceeds to step S47.

In step S46, the controller 90 determines whether or not the discharge pressure Pd of the compressor 12 acquired by the discharge pressure sensor 24 is lower than the target discharge pressure Pdt during the heating operation stored in the storage unit. If the discharge pressure Pd is lower than the target discharge pressure Pdt, the process proceeds to step S47, and if the discharge pressure Pd is the target discharge pressure Pdt, the process proceeds to step S55. In short, here, the process of increasing the current threshold value It is performed only when it is possible to increase the capacity of the air conditioner 100.

In step S47, the controller 90 changes the current threshold It. Specifically, the controller 90 raises the current threshold value It by a predetermined value γ1. The value of γ1 is preferably 1 to 4% of the design maximum value Imax of the current of the compressor 12. In this embodiment, the value of γ1 is 4% of the design maximum value Imax. The changed current threshold value It is stored in the storage unit. As a result, the controller 90 controls so that the current i of the compressor 12 becomes equal to or less than the changed current threshold value It.

Next, in step S48, the controller 90 resets the timekeeping for the fourth change process. In short, the controller 90 newly starts the time counting for the fourth change processing of the current threshold value It. Then, the process proceeds to step S55.

In step S49, the controller 90 determines whether or not the state in which the difference between the suction temperature Ti and the target temperature deviates by the second temperature difference B or more continues for the second reference time Ts2. Although not limited, for example, the second temperature difference B is 3 ° C., and the second reference time Ts2 is 10 minutes.

The first reference time Ts1 and the second reference time Ts2 may be the same time. However, by setting the first reference time Ts1 to a time shorter than the second reference time Ts2, when the difference between the suction temperature Ti and the target temperature is large, it is easy to quickly eliminate the difference.

If the difference between the suction temperature Ti and the target temperature deviates from the second temperature difference B or more by the second reference time Ts2, the process proceeds to step S50, and the difference between the suction temperature Ti and the target temperature is the second. If the state of deviation of 2 temperature differences B or more does not continue in the second reference time Ts2, the process proceeds to step S55.

In step S50, the controller 90 determines whether or not the current threshold value It is the design maximum value Imax. If the current threshold value It is the design maximum value Imax, the process proceeds to step S55. On the other hand, if the current threshold value It is not the design maximum value Imax, the process proceeds to step S51.

In step S51, the controller 90 determines whether or not the air conditioner 100 is in the heating operation. If the heating operation is in progress, the process proceeds to step S52, and if the heating operation is not in progress, the process proceeds to step S53.

In step S52, the controller 90 determines whether or not the discharge pressure Pd of the compressor 12 acquired by the discharge pressure sensor 24 is lower than the target discharge pressure Pdt during the heating operation stored in the storage unit. If the discharge pressure Pd is lower than the target discharge pressure Pdt, the process proceeds to step S53, and if the discharge pressure Pd is the target discharge pressure Pdt, the process proceeds to step S55.

In step S53, the controller 90 changes the current threshold It. Specifically, the controller 90 raises the current threshold value It by a predetermined value γ2. The value of γ2 is preferably 1 to 4% of the design maximum value Imax of the current of the compressor 12. Further, the value of γ2 is smaller than that of γ1 in step S46. Preferably, the value of γ1 is 1.5 to 3 times the value of γ2. In this embodiment, the value of γ2 is 2% of the design maximum value Imax.

Next, in step S54, the controller 90 resets the timekeeping for the fourth change process. In short, the controller 90 newly starts the time counting for the fourth change processing of the current threshold value It. Then, the process proceeds to step S55.

In step S55, it is determined whether the operation end condition of the air conditioner 100 is satisfied. An example of the operation termination condition of the air conditioner 100 is as described above. If the operation end condition is not satisfied, the process returns to step S42. When the operation end condition is satisfied, the fourth change process ends.

The flowcharts of the first change process to the fourth change process of the current threshold value It described here are merely examples and can be changed as appropriate. For example, the order of the processing steps in each flowchart may be appropriately changed within a consistent range. Further, for example, the processing steps in each flowchart may be executed simultaneously within a consistent range.

Further, for example, the processing steps in each flowchart may be appropriately omitted as long as there is no contradiction. For example, the determination in steps S45, S46, S51, and S52 in the fourth change process of the current threshold value It may be omitted.

(4) Specific Example of Time Change of Current and Current Threshold A specific example of time change of the current i and the current threshold value It of the compressor 12 in the air conditioner 100 will be described with reference to FIGS. 8 and 9. FIG. 8 is a diagram conceptually showing an example of the time change of the current i and the current threshold value It when the set value of the current threshold value It is too low. FIG. 9 is a diagram conceptually showing an example of the time change of the current i and the current threshold value It when the set value of the current threshold value It is too large.

(4-1) When the value of the current threshold value is too low With reference to FIG. 8, when the current threshold value It initially stored in the storage unit is too low, the current i of the compressor 12 and the time change of the current threshold value It A specific example will be described.

Here, it is assumed that the current threshold value It stored in the storage unit at the start of operation of the air conditioner 100 is 64% of the design maximum value Imax of the current of the compressor 12 (position (1) in FIG. 8). .. _{Further, it is assumed that the initial value I 0} of the current threshold value It is 80% of the design maximum value I max of the current of the compressor 12. Further, here, it is assumed that the air conditioner 100 is stopped for a long time before the start of operation of the air conditioner 100, and the difference between the suction temperature Ti at the start of operation of the air conditioner 100 and the target temperature is larger than 5 ° C. ..

Under this premise, when the operation of the air conditioner 100 is started, the controller 90 executes the first change process, the second change process, and the fourth change process of the current threshold value It. Further, the controller 90 also executes the third change process of the current threshold value It (here, since it is assumed that the value of the current threshold value It is too low, the third change process of the current threshold value It is not particularly described. ).

Here, since the air conditioning load is large, it is assumed that the current i of the compressor 12 becomes the current threshold value It after the start of operation.

Here, it is assumed that the difference between the suction temperature Ti and the target temperature is 5 ° C. (first temperature difference A) or more when the operation at the current threshold value It continues for 5 minutes (first reference time Ts1). .. Therefore, the process of step S47 of the fourth change process is performed, and the controller 90 raises the current threshold value It by 4% of the design maximum value Imax of the current of the compressor 12. As a result, the current threshold value It becomes 68% of the design maximum value Imax of the current of the compressor 12 (position (2) in FIG. 8).

Here, even after the current threshold value It is set to 68% of the design maximum value Imax of the current of the compressor 12, the air conditioning load is still large, and the current i of the compressor 12 is assumed to be the changed current threshold value It. .. However, in this state, the difference between the suction temperature Ti and the target temperature when the operation at the current threshold value It continues for 5 minutes after the change of the current threshold value It is assumed to be smaller than 5 ° C. On the other hand, when the operation at the current threshold value It continues for 10 minutes (second reference time Ts2) after the current threshold value It is changed, the difference between the suction temperature Ti and the target temperature is 3 ° C. (second temperature difference B) or more. Suppose there is. Therefore, the process of step S53 of the fourth change process of the current threshold value It is performed, and the controller 90 raises the current threshold value It by 2% of the design maximum value Imax of the current of the compressor 12. As a result, the current threshold value It becomes 70% of the design maximum value Imax of the current of the compressor 12 (position (3) in FIG. 8).

Here, even after the current threshold value It is set to 70% of the design maximum value Imax of the current of the compressor 12, the air conditioning load is still large, and the current i of the compressor 12 is assumed to be the changed current threshold value It. .. However, in this state, the difference between the suction temperature Ti and the target temperature when the operation at the current threshold value It is continued for 10 minutes after the change of the current threshold value It is assumed to be smaller than 3 ° C. On the other hand, it is assumed that the operation at the current threshold value It continues for 15 minutes (first time T1) after the change of the current threshold value It. Therefore, the process of step S4 of the first change process of the current threshold value It is performed, and the controller 90 raises the current threshold value It by 2% of the design maximum value Imax of the current of the compressor 12. As a result, the current threshold value It becomes 72% of the design maximum value Imax of the current of the compressor 12 (position (4) in FIG. 8).

Here, even after the current threshold value It is set to 72% of the design maximum value Imax of the current of the compressor 12, the air conditioning load is still large, and the current i of the compressor 12 becomes the changed current threshold value It. Then, the operation of the compressor 12 at the current threshold value It was continued for 45 minutes (third time T3) after the current i first reached the current threshold value It (64% of the design maximum value Imax) at that time. do. Therefore, the process of step S13 of the second change process of the current threshold value It is performed, and the controller 90 sets the current threshold value It to the initial value I ₀ (80% of the design maximum value Imax, the position (5) in FIG. 8). And.

Here, even after the current threshold value It is set to 80% of the design maximum value Imax of the current of the compressor 12, the air conditioning load is still large, and the current i of the compressor 12 is assumed to be the changed current threshold value It. .. However, the current i becomes equal to or less than the current threshold value It in less than 15 minutes (first time T1) after the change of the current threshold value It. Therefore, the current threshold value It is not changed here.

(4-2) When the value of the current threshold value is too low With reference to FIG. 9, the time change of the current i and the current threshold value It of the compressor 12 when the current threshold value It initially stored in the storage unit is too large. A specific example will be described.

Here, it is assumed that the current threshold value It stored in the storage unit at the start of operation of the air conditioner 100 is 64% of the design maximum value Imax of the current of the compressor 12 (position (1) in FIG. 9). .. _{Further, it is assumed that the initial value I 0} of the current threshold value It is 80% of the design maximum value I max of the current of the compressor 12. Further, here, it is assumed that the air conditioning load of the air conditioner 100 is relatively low.

Under this premise, when the operation of the air conditioner 100 is started, the controller 90 executes the first change process, the second change process, and the fourth change process of the current threshold value It (here, the value of the current threshold value It is Since it is assumed that the current threshold value is too large, the first, second, and fourth change processes of the current threshold value It will not be described in particular). Further, the controller 90 executes the third change process of the current threshold value It.

Here, it is assumed that the air conditioning load is small and the current i of the compressor 12 once reaches the current threshold value It after the start of operation, but becomes smaller than the current threshold value It in less than 5 minutes. Then, even in the subsequent operation, it is assumed that a predetermined period (for example, 24 hours) has elapsed without the current i of the compressor 12 reaching the current threshold value It.

In this case, since the integrated operation time of the compressor 12 at the current threshold value It during the predetermined period is shorter than 15 minutes ((second time T2)), the process of step S24 of the third change process of the current threshold value It is performed. However, the controller 90 lowers the current threshold value It by 2% of the design maximum value Imax of the current of the compressor 12. As a result, the current threshold value It is 62% of the design maximum value Imax of the current of the compressor 12 (in FIG. 9). (Position of (2)).

(5) Features (5-1)
The air conditioner 100 of the above embodiment includes a compressor 12 and a controller 90. The controller 90 controls the current i of the compressor 12 so as to be equal to or less than the current threshold value It. The controller 90 changes the current threshold value It based on the time during which the compressor 12 is operated at the current threshold value It.

In the air conditioner 100 of the above embodiment, the current threshold value It is changed according to the time when the compressor 12 is operated at the current threshold value It. Therefore, the air conditioner 100 optimizes the current threshold It, and suppresses the rise time of the air conditioner 100 from becoming long, while the rise time becomes excessively short with respect to the target time, and the power consumption at the start of operation is reduced. It is possible to suppress the occurrence of an increase situation.

(5-2)
In the air conditioner 100 of the above embodiment, the controller 90 raises the current threshold value It when the compressor 12 is operated at the current threshold value It longer than the first time T1.

In the air conditioner 100 of the above embodiment, when the compressor 12 is operated at the current threshold value It is longer than the first time T1, the current threshold value It is increased, so that the rise time of the air conditioner 100 becomes longer. It is possible to suppress the occurrence of a situation that passes.

(5-3)
In the air conditioner 100 of the above embodiment, the controller 90 raises the current threshold value It when the time during which the compressor 12 is continuously operated at the current threshold value It is longer than the first time T1.

In the air conditioner 100 of the above embodiment, control is performed to raise the current threshold value It when the compressor 12 is continuously operated at the current threshold value It longer than a predetermined time. Therefore, when the current threshold value It is too small. It is easy to improve this quickly.

(5-4)
In the air conditioner 100 of the above embodiment, the controller 90 lowers the current threshold value It when the integrated time in which the compressor 12 is operated at the current threshold value It is shorter than the second time T2 during a predetermined period.

In the air conditioner 100 of the above embodiment, control is performed to lower the current threshold It when the integrated time in which the compressor 12 is operated at the current threshold It is shorter than the second time T2 in a predetermined period, so that the air conditioner 100 starts up. It is possible to suppress the occurrence of a situation in which the time becomes too short and the power consumption increases.

(5-5)
In the air conditioner 100 of the above embodiment, the controller 90 controls the compressor 12 so as to start the operation of the air conditioner 100 one hour T1 earlier than the set schedule.

In the air conditioner 100 of the above embodiment, power consumption can be suppressed while operating so as to complete the start-up of the air conditioner 100 within the time of the precooling operation and the preheating operation during the scheduled operation.

(5-6)
In the air conditioner 100 of the above embodiment, when the current threshold value It is changed, the controller 90 changes the current threshold value It by 1 to 4% of the design maximum value Imax of the current i of the compressor 12.

In the air conditioner 100 of the above embodiment, a state in which the change in the current threshold value It is not sufficient, or a state in which the change in the current threshold value It is too large and it is necessary to change the current threshold value It in the opposite direction (hunting) occurs. Can be suppressed.

(5-7)
In the air conditioner 100 of the above embodiment, when the power is turned on to the air conditioner 100, the controller 90 controls the current of the compressor 12 to be equal to or less than the current threshold It with _{a predetermined initial value I 0 as the current threshold It.}

The appropriate value of the current threshold It varies, for example, between a season with a large load and a season with a light load. Therefore, when the air conditioner 100 is not used for a long period of time and the use is resumed after a lapse of time from the previous use, the value that was appropriate as the current threshold value It at the time of the previous use becomes the current appropriate current threshold value It. It may be significantly different from the value. Then, for example, when the current threshold value It is excessively small with respect to an appropriate value when resuming use, there is a possibility that the temperature of the temperature adjustment target does not reach the target temperature for a long time at the start of operation or the like. ..

On the other hand, in the air conditioner 100 of the above embodiment, when the power is turned on, a predetermined initial value I ₀ is used as the current threshold value It. Therefore, if a reasonably large value is adopted as the initial value I ₀ , it is possible to suppress the occurrence of a situation in which the temperature of the temperature adjustment target does not reach the target temperature for a long time at the start of operation or the like.

(5-8)
In the air conditioner 100 of the above embodiment, the controller 90 changes the _{current threshold value It to the initial value I 0} when the compressor 12 is operated at the current threshold value It longer than the third time T3.

In the air conditioner 100 of the above embodiment, when the compressor 12 is operated for a long time at the current threshold value It, in other words, when the value of the current threshold value It is too small, the current threshold value It is set to the initial value I ₀ . Can be returned. Therefore, if a reasonably large value is adopted as the initial value I ₀ , it is possible to suppress the occurrence of a situation in which the temperature of the temperature adjustment target does not reach the target temperature for a long time.

(6) Modification Example The above embodiment can be appropriately modified as shown in the following modification examples. Each modification may be applied in combination with other modifications as long as there is no contradiction.

(6-1) Modification A
In the above embodiment, it is preferable that all of the first change processing to the fourth change process of the current threshold value It is executed. However, it is not limited to this, and some of them may not be executed.

For example, when the first change process of the current threshold value It is performed, the fourth change process of the current threshold value It may not be executed. The reverse is also true.

Further, for example, the second change process of the current threshold value It may not be executed.

(6-2) Modification B
In the above embodiment, in the fourth change process of the current threshold value It, the difference between the suction temperature Ti and the target temperature deviates from the first temperature difference A or more and the second temperature difference B or more deviates from each other. Therefore, the amount of increase in the current threshold value It is set to a different value. However, the present invention is not limited to this, and for example, the first reference time Ts1 in the fourth change processing of the current threshold value It is set to a time shorter than the second reference time Ts2, and the first value γ1 and the second value γ2 are set. May use the same value.

(6-3) Modification C
In the above embodiment, in the fourth change process of the current threshold value It, the difference between the suction temperature Ti and the target temperature deviates from the first temperature difference A or more and the second temperature difference B or more deviates from each other. So, different processing is done. However, it is not limited to this.

For example, in the fourth change process of the current threshold value It, when the compressor 12 is operated at the current threshold value It, the difference between the suction temperature Ti and the target temperature is compared with a single threshold value, and the suction temperature Ti and the target temperature are compared. When the state in which the difference between the current threshold value and the threshold value is different from each other continues for a predetermined time, a process of increasing the current threshold value It by a predetermined amount may be executed.

(6-4) Modification D
In the above embodiment, the controller 90 performs a process of raising the current threshold value It when the time during which the compressor 12 is continuously operated at the current threshold value It is longer than the first time T1.

The controller 90 replaces or in addition to this, the current threshold when the integrated time during which the compressor 12 is operated at the current threshold It during a predetermined period (for example, within 24 hours) is longer than the predetermined time. A process of increasing It may be performed.

(6-5) Modification E
In the above embodiment, the controller 90 sets the current threshold value It to the initial value I ₀ when the power of the air conditioner 100 is turned on, but the controller 90 is not limited to this. For example, when the power of the air conditioner 100 is turned on other than the first time, the current threshold value It stored in the storage unit may be used as it is.

<Additional notes>
Although the embodiments of the present disclosure have been described above, it will be understood that various modifications of the forms and details are possible without departing from the purpose and scope of the present disclosure described in the claims. ..

The present disclosure is widely applicable and useful in refrigeration cycle equipment.

12 Compressor 90 controller (control unit)
100 Air conditioner (refrigeration cycle device)
Imax Design maximum value It current threshold

JP-A-2009-243814

Claims (10)

Compressor (12) and
A control unit (90) that controls the current of the compressor so that it is equal to or lower than the current threshold value (It).
With
The control unit changes the current threshold value based on the time during which the compressor is operated at the current threshold value.
Refrigeration cycle device (100). The control unit raises the current threshold when the time during which the compressor is operated at the current threshold is longer than the first hour.
The refrigeration cycle apparatus according to claim 1. The control unit raises the current threshold when the time during which the compressor is continuously operated at the current threshold is longer than the first time.
The refrigeration cycle apparatus according to claim 2. The control unit raises the current threshold when the time for operating the compressor at the current threshold is longer than the first time, and when the time for operating the compressor at the current threshold is shorter than the second time. To lower the current threshold,
The refrigeration cycle apparatus according to claim 1. The control unit raises the current threshold value when the time during which the compressor is continuously operated at the current threshold value is longer than the first time, and the compressor is operated at the current threshold value during a predetermined period. When the integration time is shorter than the second time, the current threshold value is lowered.
The refrigeration cycle apparatus according to claim 4. The control unit controls the compressor so as to start the operation of the refrigeration cycle device one hour earlier than the set schedule.
The refrigeration cycle apparatus according to any one of claims 2 to 5. The control unit lowers the current threshold when the integrated time during which the compressor is operated at the current threshold is shorter than the second time during a predetermined period.
The refrigeration cycle apparatus according to any one of claims 1 to 3. When the current threshold value is changed, the control unit changes the current threshold value by 1 to 4% of the design maximum value (Imax) of the current of the compressor.
The refrigeration cycle apparatus according to any one of claims 1 to 7. When the power is turned on to the refrigeration cycle device, the control unit controls the current of the compressor so as to be equal to or less than the current threshold value, using a predetermined initial value as the current threshold value.
The refrigeration cycle apparatus according to any one of claims 1 to 8. When the refrigeration cycle device is first used, the control unit controls the current of the compressor so as to be equal to or lower than the current threshold value, using a predetermined initial value as the current threshold value.
The control unit changes the current threshold value to the initial value when the time during which the compressor is operated at the current threshold value is longer than the third time.
The refrigeration cycle apparatus according to any one of claims 1 to 9.

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