WO2014103620A1

WO2014103620A1 - Refrigeration device

Info

Publication number: WO2014103620A1
Application number: PCT/JP2013/082356
Authority: WO
Inventors: 大介豊田; 敦小倉; 正志一桐
Original assignee: ダイキン工業株式会社
Priority date: 2012-12-28
Filing date: 2013-12-02
Publication date: 2014-07-03
Also published as: JP2014142168A

Abstract

Provided is a refrigeration device using R32 as a coolant, and capable of quickly and appropriately controlling an expansion mechanism when the expansion mechanism is controlled by using the discharge temperature of the compressor thereof, and even when the compressor operates in a low-rotational-speed region. An air-conditioning device (10) using R32 as a coolant is equipped with a compressor (31), an outside heat exchanger, an outside expansion valve (36), an inside heat exchanger, a discharge-temperature sensor (51), an expansion adjustment unit (41a), and a time-interval-changing unit (41c). The expansion valve causes a high-pressure coolant discharged from a condenser (outside heat exchanger or inside heat exchanger) to expand. The discharge-temperature sensor detects the discharge temperature of the coolant discharged from the compressor. The expansion adjustment unit adjusts and controls the aperture of the outside expansion valve by using the discharge temperature. The time-interval-changing unit changes the control time interval of the expansion adjustment unit. When the rotational speed of the compressor is below a threshold, the time-interval-changing unit changes the control time interval from a first time interval to a second time interval which is longer than the first time interval.

Description

Refrigeration equipment

The present invention relates to a refrigeration apparatus.

A refrigerating apparatus using R32 as a refrigerant is known (for example, Patent Document 1 (Japanese Patent Laid-Open No. 2012-122777)). R32 is a refrigerant having a smaller density than R410A, which has been conventionally used as a refrigerant.

In such a refrigeration apparatus, the expansion mechanism may be controlled using the discharge temperature of the compressor. For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2012-122777), the opening degree of the expansion valve is controlled using the discharge temperature of the compressor.

By the way, at present, in a refrigeration apparatus, it is required to operate a compressor in a lower rotational speed range than before in order to deal with a wide range of loads with a single compressor. In a refrigeration system that uses R32 as a refrigerant, the compressor is operated in such a low rotation speed range, and the discharge valve of the compressor is used by using the discharge temperature of the compressor as in Patent Document 1 (Japanese Patent Application Laid-Open No. 2012-122777). When the opening degree is controlled, there are the following problems.

When the compressor is operated in a low rotation speed range, the amount of refrigerant circulating in the refrigeration system is reduced. In particular, when R32 is used as the refrigerant, since the density of R32 is small, the circulation amount of the refrigerant in the refrigeration apparatus tends to be smaller than when R410A is used as the refrigerant. In a state where the circulation amount of the refrigerant is small, it takes time until an increase in the discharge temperature is observed even if the opening of the expansion valve is reduced. For this reason, the opening degree of the expansion valve may be excessively reduced, and the discharge temperature may increase excessively. In addition, when the discharge temperature rises too much, it takes time until the drop in the discharge temperature is observed even if the opening of the expansion valve is increased. Therefore, the opening degree of the expansion valve may be excessively increased, and the discharge temperature may be excessively lowered. As described above, when the compressor is operated in a low rotation speed range, control hunting occurs, so that the expansion valve cannot be adjusted to an appropriate opening degree, or in order to adjust the expansion valve to an appropriate opening degree. The problem of taking time can occur.

The problem of the present invention is that, in a refrigeration apparatus that uses R32 as a refrigerant, when the expansion mechanism is controlled using the discharge temperature of the compressor, even when the compressor is operated in a low rotation speed range, An object of the present invention is to provide a refrigeration apparatus capable of controlling an expansion mechanism quickly and appropriately.

The refrigeration apparatus according to the first aspect of the present invention is a refrigeration apparatus that uses R32 as a refrigerant. The refrigeration apparatus includes a compressor, a condenser, an expansion mechanism, an evaporator, a temperature detection unit, an expansion adjustment unit, and a time interval change unit. The compressor sucks low-pressure refrigerant from the suction flow path, compresses the refrigerant, and discharges high-pressure refrigerant. The condenser condenses the high-pressure refrigerant discharged from the compressor. The expansion mechanism expands the high-pressure refrigerant that has exited the condenser. The evaporator evaporates the refrigerant expanded by the expansion mechanism. The temperature detection unit detects the discharge temperature of the refrigerant discharged from the compressor. The expansion adjustment unit performs adjustment control of the expansion mechanism using the discharge temperature. The time interval changing unit changes the control time interval of the expansion adjusting unit. The time interval changing unit changes the control time interval from the first time interval to a second time interval longer than the first time interval when the rotation speed of the compressor becomes smaller than the threshold value.

Here, when the rotation speed of the compressor is smaller than the threshold value, the control time interval of the adjustment control of the expansion mechanism is changed to a second time interval longer than the first time interval. Therefore, the expansion adjusting unit can control the expansion mechanism after accurately grasping the discharge temperature even when the rotation speed of the compressor is small and the circulation amount of the refrigerant is small. As a result, even when the rotation speed of the compressor is small, the expansion mechanism can be controlled promptly and appropriately without causing control hunting.

In particular, here, since the control time interval is changed from the first time interval to the second time interval based on the comparison result between the rotation speed of the compressor and the threshold value, with a simple configuration and easy processing, Even when the rotation speed of the compressor is small, the expansion mechanism can be controlled promptly and appropriately.

The refrigeration apparatus according to the second aspect of the present invention is the refrigeration apparatus according to the first aspect, wherein the time interval changing unit sets the control time interval to the second time when the rotation speed of the compressor is equal to or greater than a threshold value. The time interval is changed to the first time interval.

Here, when the rotation speed of the compressor is equal to or greater than the threshold, the control time interval of the adjustment control of the expansion mechanism is changed to the first time interval shorter than the second time interval. Therefore, when the refrigerant circulation amount is large and the rotation speed of the compressor is equal to or greater than the threshold value, the expansion mechanism can be quickly adjusted and controlled.

The refrigeration apparatus according to the third aspect of the present invention is a refrigeration apparatus that uses R32 as a refrigerant. The refrigeration apparatus includes a compressor, a condenser, an expansion mechanism, an evaporator, a temperature detection unit, an expansion adjustment unit, and a feedback amount change unit. The compressor sucks low-pressure refrigerant from the suction flow path, compresses the refrigerant, and discharges high-pressure refrigerant. The condenser condenses the high-pressure refrigerant discharged from the compressor. The expansion mechanism expands the high-pressure refrigerant that has exited the condenser. The evaporator evaporates the refrigerant expanded by the expansion mechanism. The temperature detection unit detects the discharge temperature of the refrigerant discharged from the compressor. The expansion adjustment unit performs adjustment control of the expansion mechanism using the discharge temperature. The feedback amount changing unit changes the feedback amount of the expansion mechanism by the expansion adjusting unit. The feedback amount changing unit changes the feedback amount from the first amount to a second amount smaller than the first amount when the rotation speed of the compressor becomes smaller than the threshold value.

Here, when the rotation speed of the compressor is smaller than the threshold value, the feedback amount of the expansion mechanism by the expansion adjusting unit is changed from the first amount to the second amount smaller than the first amount. Therefore, the expansion adjusting unit does not excessively adjust the expansion mechanism when the rotation speed of the compressor is small and the circulation amount of the refrigerant is small. As a result, even when the rotation speed of the compressor is small, the expansion mechanism can be controlled promptly and appropriately without causing control hunting.

In particular, here, since the feedback amount of the expansion mechanism is changed based on the comparison result between the rotation speed of the compressor and the threshold value, the rotation speed of the compressor is small with a simple configuration and easy processing. In addition, the expansion mechanism can be appropriately controlled.

A refrigeration apparatus according to a fourth aspect of the present invention is the refrigeration apparatus according to the third aspect, in which the feedback amount changing unit changes the feedback amount to the second amount when the rotation speed of the compressor becomes equal to or greater than a threshold value. To change to the first amount.

Here, when the rotation speed of the compressor is equal to or greater than the threshold value, the feedback amount of the expansion mechanism is changed to the first amount larger than the second amount. Therefore, when the refrigerant circulation amount is large and the rotation speed of the compressor is equal to or greater than the threshold value, the expansion mechanism can be quickly adjusted and controlled.

In the refrigeration apparatus according to the first aspect of the present invention, when the rotation speed of the compressor is smaller than the threshold value, the control time interval of the expansion mechanism adjustment control is changed to a second time interval longer than the first time interval. . Therefore, the expansion adjusting unit can control the expansion mechanism after accurately grasping the discharge temperature even when the rotation speed of the compressor is small and the circulation amount of the refrigerant is small. As a result, even when the rotation speed of the compressor is small, the expansion mechanism can be controlled promptly and appropriately without causing control hunting.

In the refrigeration apparatus according to the second aspect of the present invention, when the refrigerant circulation amount is large and the rotation speed of the compressor is equal to or higher than the threshold value, the expansion mechanism can be adjusted and controlled quickly.

In the refrigeration apparatus according to the third aspect of the present invention, when the rotation speed of the compressor is smaller than the threshold value, the feedback amount of the expansion mechanism by the expansion adjustment unit is changed from the first amount to the second amount smaller than the first amount. Be changed. Therefore, the expansion adjusting unit does not excessively adjust the expansion mechanism when the rotation speed of the compressor is small and the circulation amount of the refrigerant is small. As a result, even when the rotation speed of the compressor is small, the expansion mechanism can be controlled promptly and appropriately without causing control hunting.

In the refrigeration apparatus according to the fourth aspect of the present invention, when the refrigerant circulation amount is large and the rotation speed of the compressor is equal to or higher than the threshold value, the expansion mechanism can be adjusted and controlled quickly.

It is a schematic block diagram of the air conditioning apparatus which concerns on 1st Embodiment of the freezing apparatus of this invention. It is a block diagram of the air conditioning apparatus of FIG. It is a flowchart for demonstrating the change process of the control time interval of an expansion | swelling adjustment part of the air conditioning apparatus of FIG. It is a schematic block diagram of the air conditioning apparatus which concerns on 2nd Embodiment of the freezing apparatus of this invention. It is a block diagram of the air conditioning apparatus of FIG. It is a flowchart for demonstrating the change process of the feedback amount of the outdoor expansion valve by the expansion adjustment part of the air conditioning apparatus of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the following embodiment of this invention can be suitably changed in the range which does not deviate from the meaning of this invention.

<First Embodiment>
(1) Overall Configuration The air conditioner 10 as a refrigeration apparatus according to the first embodiment of the present invention is an air conditioner that can be operated by switching between a cooling operation and a heating operation. However, the air conditioner 10 may not be operable by switching between the cooling operation and the heating operation, and may be an air conditioner capable of performing only the cooling operation or the heating operation.

As shown in FIG. 1, the air conditioner 10 mainly includes an indoor unit 20, an outdoor unit 30, and a control unit 40.

The air conditioner 10 has a refrigerant circuit 1 filled with R32 as a refrigerant. The refrigerant circuit 1 has an indoor circuit 1 a accommodated in the indoor unit 20 and an outdoor circuit 1 b accommodated in the outdoor unit 30. The indoor side circuit 1a and the outdoor side circuit 1b are connected by a liquid refrigerant communication pipe 71 and a gas refrigerant communication pipe 72.

(2) Detailed Configuration (2-1) Indoor Unit The indoor unit 20 is installed in a room that is subject to air conditioning. The indoor unit 20 includes an indoor heat exchanger 21 and an indoor fan 22.

The indoor heat exchanger 21 is a cross fin type fin-and-tube heat exchanger composed of heat transfer tubes and a large number of heat transfer fins. During the cooling operation, the indoor heat exchanger 21 functions as an evaporator that evaporates refrigerant expanded by an outdoor expansion valve 36 described later, and cools indoor air. The indoor heat exchanger 21 functions as a condenser that condenses high-pressure refrigerant discharged from a compressor 31 described later during heating operation, and heats indoor air. The liquid side of the indoor heat exchanger 21 is connected to the liquid refrigerant communication pipe 71, and the gas side of the indoor heat exchanger 21 is connected to the gas refrigerant communication pipe 72.

The indoor fan 22 is driven by a fan motor. The indoor fan 22 takes in indoor air and blows it to the indoor heat exchanger 21, and promotes heat exchange between the refrigerant flowing through the indoor heat exchanger 21 and the indoor air.

(2-2) Outdoor Unit The outdoor unit 30 mainly includes a compressor 31, a four-way switching valve 33, an outdoor heat exchanger 34, an outdoor fan 35, an outdoor expansion valve 36, and a discharge temperature sensor 51. The compressor 31, the four-way switching valve 33, the outdoor heat exchanger 34, and the outdoor expansion valve 36 are connected by refrigerant piping.

(2-2-1) Connection of Components by Refrigerant Piping Connection of components by the refrigerant piping of the outdoor unit 30 will be described.

The suction port of the compressor 31 and the four-way switching valve 33 are connected by a suction pipe 81. The discharge port of the compressor 31 and the four-way switching valve 33 are connected by a discharge pipe 82. The four-way switching valve 33 and the gas side of the outdoor heat exchanger 34 are connected by a first gas refrigerant pipe 83. The outdoor heat exchanger 34 and the liquid refrigerant communication pipe 71 are connected by a liquid refrigerant pipe 84. The liquid refrigerant pipe 84 is provided with an outdoor expansion valve 36. The four-way switching valve 33 and the gas refrigerant communication pipe 72 are connected by a second gas refrigerant pipe 85.

(2-2-2) Compressor The compressor 31 drives the compression mechanism with a motor, thereby sucking low-pressure gas refrigerant from the suction pipe 81 and supplying the high-pressure gas refrigerant compressed by the compression mechanism to the discharge pipe 82. Discharge. Although the compressor 31 is a rotary compressor, it is not limited to this, For example, a scroll compressor may be sufficient.

The compressor 31 is an inverter type compressor capable of changing the rotation speed N (the rotation speed of the motor of the compressor 31). The movement of the compressor 31 is controlled by a compressor control unit 41b described later. The compressor control unit 41 b rotates the compressor 31 in accordance with the degree of deviation between the temperature (room temperature) of the air conditioning target space and the set temperature, and the discharge temperature Td of the compressor 31 detected by the discharge temperature sensor 51. Control the number N.

(2-2-3) Four-way switching valve The four-way switching valve 33 switches the flow direction of the refrigerant when the air-conditioning apparatus 10 is switched between the cooling operation and the heating operation. During the cooling operation, the discharge pipe 82 and the first gas refrigerant pipe 83 are connected, and the suction pipe 81 and the second gas refrigerant pipe 85 are connected (see the solid line in FIG. 1). On the other hand, during the heating operation, the discharge pipe 82 and the second gas refrigerant pipe 85 are connected, and the suction pipe 81 and the first gas refrigerant pipe 83 are connected (see the broken line in FIG. 1).

(2-2-4) Outdoor Heat Exchanger The outdoor heat exchanger 34 is a cross-fin type fin-and-tube heat exchanger composed of heat transfer tubes and a large number of heat transfer fins. The outdoor heat exchanger 34 functions as a condenser that condenses the high-pressure refrigerant discharged from the compressor 31 by exchanging heat between the outdoor air and the refrigerant during the cooling operation. The outdoor heat exchanger 34 functions as an evaporator that evaporates the refrigerant expanded by the outdoor expansion valve 36 by exchanging heat between the outdoor air and the refrigerant during heating operation.

(2-2-5) Outdoor Fan The outdoor fan 35 is rotated by a fan motor and takes outdoor air into the outdoor unit 30. The taken outdoor air passes through the outdoor heat exchanger 34 and is finally discharged out of the outdoor unit 30. The outdoor fan 35 promotes heat exchange between the refrigerant flowing in the outdoor heat exchanger 34 and outdoor air.

(2-2-6) Outdoor Expansion Valve The outdoor expansion valve 36 is an example of an expansion mechanism, and an electric expansion valve with a variable opening provided for adjusting the pressure and flow rate of the refrigerant flowing in the refrigerant circuit 1. It is. During the cooling operation, the outdoor expansion valve 36 expands the refrigerant flowing from the outdoor heat exchanger 34 that functions as a condenser to the indoor heat exchanger 21 that functions as an evaporator. During the heating operation, the outdoor expansion valve 36 expands the refrigerant flowing from the indoor heat exchanger 21 that functions as a condenser to the outdoor heat exchanger 34 that functions as an evaporator. The opening degree of the outdoor expansion valve 36 is adjusted and controlled by an expansion adjusting unit 41a of the control unit 40 described later.

(2-2-7) Discharge Temperature Sensor The discharge temperature sensor 51 is an example of a temperature detection unit. The discharge temperature sensor 51 is a thermistor for detecting the temperature of the refrigerant discharged from the compressor 31 (discharge temperature Td). The discharge temperature sensor 51 is provided outside the compressor 31, more specifically, near the discharge port of the compressor 31 in the discharge pipe 82. The attachment position of the discharge temperature sensor 51 is not limited to this. The discharge temperature sensor 51 may be attached to an appropriate position for grasping the temperature of the refrigerant discharged from the compressor 31. The discharge temperature Td detected by the discharge temperature sensor 51 is used for control of the rotational speed N of the compressor 31 and adjustment control of the opening degree of the outdoor expansion valve 36.

(2-3) Control Unit The control unit 40 controls the movement of the air conditioner 10. In FIG. 2, the block diagram of the air conditioning apparatus 10 containing the control unit 40 is shown.

The control unit 40 includes a control unit 41 formed of a microcomputer or the like, a storage unit 42 formed of a memory such as a RAM or a ROM, and an input unit 43 (remote control). As shown in FIG. 2, the control unit 40 includes components of the indoor unit 20 and the outdoor unit 30 (compressor 31, four-way switching valve 33, outdoor fan 35, outdoor expansion valve 36, indoor fan 22, discharge temperature sensor 51, etc. ) And are electrically connected.

The control unit 41 controls the air conditioner 10 by reading and executing the program stored in the storage unit 42. The control unit 41 exchanges control signals with the input unit 43 in order to operate the indoor unit 20. And the control part 41 controls the driving | operation of the air conditioning apparatus 10 according to the input (The operation / stop of the air conditioning apparatus 10, an operation mode (cooling mode / heating mode), preset temperature, etc.) to the input part 43. . The control unit 41 controls various devices of the indoor unit 20 and the outdoor unit 30 according to the operating conditions and the operating state of the air conditioner 10.

In addition, the control part 41 has the expansion adjustment part 41a, the compressor control part 41b, and the time interval change part 41c as a function part. The expansion adjustment unit 41a, the compressor control unit 41b, and the time interval change unit 41c will be described later.

The storage unit 42 stores programs to be executed by the control unit 41 and various information. The storage unit 42 has a time interval storage area 42a for storing the time interval Δt. The time interval storage area 42a will be described later.

(2-3-1) Control Unit (2-3-1-1) Expansion Adjusting Unit The expansion adjusting unit 41a opens the opening of the outdoor expansion valve 36 in accordance with the operating conditions and operating conditions of the air conditioner 10. Adjust the control.

The expansion adjusting unit 41a uses the value of the discharge temperature Td measured by the discharge temperature sensor 51 as one of the parameters for adjusting and controlling the opening degree of the outdoor expansion valve 36. Specifically, when the discharge temperature Td is lower than the target temperature, the expansion adjusting unit 41a performs control to reduce the opening degree of the outdoor expansion valve 36. On the other hand, when the discharge temperature Td is higher than the target temperature, the expansion adjusting unit 41a performs control to increase the opening degree of the outdoor expansion valve 36.

The adjustment control of the opening degree of the outdoor expansion valve 36 using the discharge temperature Td as a parameter of the expansion adjusting unit 41a is executed at every control time interval. The control time interval of the expansion adjustment unit 41a is the time interval Δt stored in the time interval storage area 42a of the storage unit 42.

(2-3-1-2) Compressor Control Unit The compressor control unit 41b starts / stops the compressor 31 and rotates the compressor 31 according to the operating conditions, operating conditions, etc. of the air conditioner 10. The number N (the rotational speed N of the motor of the compressor 31) is determined and controlled. For example, the compressor control unit 41b determines the rotation speed N of the compressor 31 according to the degree of divergence between the temperature (room temperature) of the space to be air-conditioned of the air conditioning apparatus 10 and the set temperature, and the rotation speed N The compressor 31 is controlled so that

(2-3-1-3) Control time changing unit The time interval changing unit 41c changes the control time interval of the expansion adjusting unit 41a by rewriting the value of the time interval Δt stored in the time interval storage area 42a. . The change of the control time interval of the expansion adjusting unit 41a by the time interval changing unit 41c will be described later.

(2-3-2) Storage Unit (2-3-2-1) Time Interval Storage Area In the time interval storage area 42a, the expansion adjusting unit 41a has an outdoor expansion valve according to the discharge temperature Td of the compressor 31. A time interval Δt is stored as a control time interval for performing the adjustment control of the opening degree of 36.

The time interval Δt in the time interval storage area 42a is changed to the first time interval A1 or the second time interval A2 by being changed by the time interval changing unit 41c. The second time interval A2 is a time interval longer than the first time interval. For example, the first time interval A1 is 10 seconds and the second time interval A2 is 30 seconds.

(2-3-3) Input Unit The input unit 43 is a remote controller for the air conditioning apparatus 10. The input unit 43 receives various inputs from the user of the air conditioning apparatus 10. Various inputs received from the user by the input unit 43 include an operation / stop command for the air conditioner 10, an operation mode (heating mode / cooling mode) of the air conditioner 10, a set temperature of the air conditioner 10, and the like.

(3) Change processing of control time interval of expansion adjusting unit Hereinafter, control time interval of the expansion adjusting unit 41a (the expansion adjusting unit 41a performs adjustment control of the outdoor expansion valve 36 according to the discharge temperature Td of the compressor 31). (Time interval) to be changed will be described with reference to the flowchart of FIG. The process of changing the control time interval of the outdoor expansion valve 36 is repeatedly executed during operation of the air conditioner 10.

In step S1, the time interval changing unit 41c acquires the rotational speed N of the compressor 31 from the compressor control unit 41b. Thereafter, the process proceeds to step S2.

In step S2, the time interval changing unit 41c determines whether or not the rotation speed N of the compressor 31 acquired in step S1 is smaller than the threshold value N1.

Note that the threshold value N1 does not cause control hunting even when the adjustment of the opening degree of the outdoor expansion valve 36 is performed at the first time interval A1 when the rotation speed N of the compressor 31 is operated as the threshold value N1. And, it is determined to be as small as possible. The threshold value N1 is determined based on actual machine test results of the air conditioner 10 and the like.

If it is determined in step S2 that the rotational speed N of the compressor 31 is smaller than the threshold value N1, the process proceeds to step S3. On the other hand, if it is determined in step S2 that the rotation speed N of the compressor 31 is greater than or equal to the threshold value N1, the process proceeds to step S5.

In step S3, the time interval changing unit 41c determines whether or not the time interval Δt stored in the time interval storage area 42a is the first time interval A1. When it is determined that the time interval Δt stored in the time interval storage area 42a is the first time interval A1, the process proceeds to step S4. On the other hand, when it is determined that the time interval Δt stored in the time interval storage area 42a is not the first time interval A1 (the second time interval A2), the process is terminated.

In step S4, the time interval changing unit 41c changes the time interval Δt stored in the time interval storage area 42a to the second time interval A2. Thereafter, the process ends.

In step S5, the time interval changing unit 41c determines whether or not the time interval Δt stored in the time interval storage area 42a is the second time interval A2. When it is determined that the time interval Δt stored in the time interval storage area 42a is the second time interval A2, the process proceeds to step S6. On the other hand, when it is determined that the time interval Δt stored in the time interval storage area 42a is not the second time interval A2 (the first time interval A1), the process is terminated.

In step S6, the time interval changing unit 41c changes the time interval Δt stored in the time interval storage area 42a to the first time interval A1. Thereafter, the process ends.

By performing the above processing, when the rotation speed N of the compressor 31 becomes smaller than the threshold value N1, the control time interval for adjusting and controlling the outdoor expansion valve 36 according to the discharge temperature Td is adjusted by the expansion adjusting unit 41a. The second time interval A2. That is, the time interval changing unit 41c sets the control time interval of the expansion adjusting unit 41a to the first time interval when the rotation speed N of the compressor 31 is smaller than the threshold value N1 from a value equal to or greater than the threshold value N1. A1 is changed to a second time interval A2 that is longer than the first time interval A1.

On the other hand, when the rotation speed N of the compressor 31 is equal to or higher than the threshold value N1, the control time interval during which the expansion adjustment unit 41a adjusts and controls the outdoor expansion valve 36 according to the discharge temperature Td of the compressor 31 is the first time. One hour interval A1. That is, the time interval changing unit 41c changes the control time interval of the expansion adjusting unit 41a from the second time interval A2 when the rotation speed N of the compressor becomes a threshold value N1 or more from a value smaller than the threshold value N1. Change to the first time interval A1.

As a result, control hunting can be prevented in the low rotation speed region (rotation speed N <threshold value N1) of the compressor 31, and when the rotation speed N of the compressor 31 is relatively large (revolution speed N ≧ threshold value N1). Case), the opening degree of the outdoor expansion valve 36 can be adjusted and controlled quickly.

In particular, here, the rotation speed N of the compressor 31 is compared with the threshold value N1, and the control time interval is switched between two values (first time interval A1 and second time interval A2) according to the comparison result. Therefore, the above effect can be realized with a simple configuration and easy processing.

(4) Features (4-1)
The air conditioning apparatus 10 of the present embodiment is a refrigeration apparatus that uses R32 as a refrigerant. The air conditioner 10 includes a compressor 31, a condenser (indoor heat exchanger 21 or outdoor heat exchanger 34), an outdoor expansion valve 36 as an expansion mechanism, and an evaporator (outdoor heat exchanger 34 or indoor heat exchange). 21), a discharge temperature sensor 51 as a temperature detecting unit, an expansion adjusting unit 41a, and a time interval changing unit 41c. The compressor 31 sucks the low-pressure refrigerant from the suction pipe 81, compresses the refrigerant, and discharges the high-pressure refrigerant. The condenser (the indoor heat exchanger 21 or the outdoor heat exchanger 34) condenses the high-pressure refrigerant discharged from the compressor 31. The outdoor expansion valve 36 expands the high-pressure refrigerant that has exited the condenser (the indoor heat exchanger 21 or the outdoor heat exchanger 34). The evaporator (the outdoor heat exchanger 34 or the indoor heat exchanger 21) evaporates the refrigerant expanded by the outdoor expansion valve 36. The discharge temperature sensor 51 detects the discharge temperature Td of the refrigerant discharged from the compressor 31. The expansion adjusting unit 41a performs adjustment control of the outdoor expansion valve 36 using the discharge temperature Td. The time interval changing unit 41c changes the control time interval of the expansion adjusting unit 41a. The time interval changing unit 41c changes the control time interval from the first time interval A1 to the second time interval A2 longer than the first time interval A1 when the rotation speed N of the compressor 31 becomes smaller than the threshold value N1. change.

Here, when the rotation speed N of the compressor 31 is smaller than the threshold value N1, the control time interval of the adjustment control of the outdoor expansion valve 36 is changed to the second time interval A2 longer than the first time interval A1. Therefore, the expansion adjusting unit 41a can control the outdoor expansion valve 36 while accurately grasping the discharge temperature Td even when the rotation speed of the compressor 31 is small and the circulation amount of the refrigerant is small. As a result, even when the rotation speed N of the compressor 31 is small, the outdoor expansion valve 36 can be controlled promptly and appropriately without causing control hunting.

In particular, since the control time interval is changed from the first time interval A1 to the second time interval A2 based on the comparison result between the rotation speed N of the compressor 31 and the threshold value N1, here, a simple configuration, and Even when the rotation speed N of the compressor 31 is small, the outdoor expansion valve 36 can be quickly and appropriately controlled by an easy process.

(4-2)
In the air conditioner 10 of the present embodiment, the time interval changing unit 41c changes the control time interval from the second time interval A2 to the first time interval when the rotation speed N of the compressor 31 is equal to or greater than the threshold value N1. Change to A1.

Here, when the rotation speed N of the compressor 31 is equal to or greater than the threshold value N1, the control time interval of the adjustment control of the outdoor expansion valve 36 is changed to the first time interval A1 shorter than the second time interval A2. Therefore, when the refrigerant circulation amount is large and the rotation speed N of the compressor 31 is greater than or equal to the threshold value N1, adjustment control of the outdoor expansion valve 36 can be performed quickly.

(5) Modifications Modifications of the present embodiment are shown below. A plurality of modified examples may be appropriately combined.

(5-1) Modification 1A
In the above embodiment, the number of indoor units 20 is one, but a plurality of units may be used. The plurality of indoor units may each be provided with an indoor expansion valve as an expansion mechanism. Then, the expansion adjusting unit 41a changes the adjustment control of the plurality of expansion mechanisms (outdoor expansion valve and indoor expansion valve) according to the time interval Δt (the rotation speed N of the compressor 31) stored in the time interval storage area 42a. The time interval Δt) may be executed as the control time interval.

(5-2) Modification 1B
In the said embodiment, although an expansion mechanism is the outdoor expansion valve 36, it is not limited to this. The expansion mechanism only needs to expand the high-pressure refrigerant that has exited the condenser (the indoor heat exchanger 21 or the outdoor heat exchanger 34) and adjust the pressure and flow rate of the refrigerant. The expansion adjusting unit 41a is not limited to the one that adjusts the opening degree of the outdoor expansion valve 36, and may be any unit that can adjust and control refrigerant pressure change and flow rate adjustment by the expansion mechanism. For example, the expansion mechanism may be a plurality of capillary tubes having different characteristics, and the expansion adjustment unit may change the capillary tube through which the refrigerant flows by controlling an electric valve.

(5-3) Modification 1C
In the above embodiment, the control time interval of the expansion adjustment unit 41a is changed between the first time interval A1 and the second time interval A2 depending on whether or not the rotational speed N of the compressor 31 is smaller than the threshold value N1 of 1. However, the present invention is not limited to this. A plurality of threshold values are prepared, and the control time interval may be changed in multiple stages depending on whether or not the threshold value is smaller than each threshold value.

Second Embodiment
(1) Overall Configuration An air conditioner 110 as a refrigeration apparatus according to the second embodiment of the present invention is the same as the air conditioner 10 of the first embodiment except for a control unit 140 (see FIG. 4).

(2) Detailed configuration As described above, the air-conditioning apparatus 110 is the same as the air-conditioning apparatus 10 except for the control unit 140.

(2-1) Control Unit The control unit 140 controls the movement of the air conditioner 110. FIG. 5 shows a block diagram of the air conditioner 110 including the control unit 140.

The control unit 140 includes a control unit 141 formed of a microcomputer or the like, a storage unit 142 formed of a memory such as a RAM or a ROM, and an input unit 43 (remote control). As shown in FIG. 5, the control unit 140 includes components of the indoor unit 20 and the outdoor unit 30 (compressor 31, four-way switching valve 33, outdoor fan 35, outdoor expansion valve 36, indoor fan 22, discharge temperature sensor 51, etc. ) And are electrically connected.

The control part 141 controls the air conditioning apparatus 110 by reading and executing the program memorize | stored in the memory | storage part 142. FIG. The control unit 141 exchanges control signals with the input unit 43 in order to operate the indoor unit 20. And the control part 141 controls the driving | operation of the air conditioning apparatus 110 according to the input (The operation / stop of the air conditioning apparatus 110, an operation mode (cooling mode / heating mode), preset temperature etc.) to the input part 43. . The control unit 141 controls various devices of the indoor unit 20 and the outdoor unit 30 according to the operating conditions and the operating state of the air conditioner 110.

The control unit 141 includes an expansion adjustment unit 141a, a compressor control unit 41b, and a feedback amount changing unit 141d as functional units. The expansion adjusting unit 141a and the feedback amount changing unit 141d will be described later. Since the compressor control unit 41b is the same as that of the first embodiment, the description thereof is omitted.

The storage unit 142 stores a program to be executed by the control unit 141 and various types of information. The storage unit 142 includes a feedback amount storage area 142b that stores the feedback amount ΔF. Here, the feedback amount ΔF is adjusted once by the expansion adjusting unit 141a when the expansion adjusting unit 141a performs the adjustment control of the opening degree of the outdoor expansion valve 36 using the discharge temperature Td of the compressor 31. It is the adjustment amount [%] of the opening degree of the outdoor expansion valve 36 that is adjusted in the above. How the feedback amount ΔF is used will be described later.

(2-1-1) Control Unit (2-1-1-1) Expansion Adjustment Unit The expansion adjustment unit 141a opens the opening of the outdoor expansion valve 36 in accordance with the operating conditions and operating conditions of the air conditioner 110. Adjust the control.

The expansion adjusting unit 141a uses the value of the discharge temperature Td measured by the discharge temperature sensor 51 as one of parameters for adjusting and controlling the opening degree of the outdoor expansion valve 36. Specifically, the expansion adjusting unit 141a performs control to reduce the opening degree of the outdoor expansion valve 36 when the discharge temperature Td is lower than the target temperature. On the other hand, when the discharge temperature Td is higher than the target temperature, the expansion adjusting unit 141a performs control to increase the opening degree of the outdoor expansion valve 36. In addition, when performing the adjustment control of the opening degree of the outdoor expansion valve 36 by using the discharge temperature Td, the expansion adjustment unit 141a increases the outdoor amount by the feedback amount ΔF stored in the feedback amount storage area 142b per one adjustment control. The opening degree of the expansion valve 36 is adjusted. That is, when the discharge temperature Td is lower than the target temperature, the expansion adjusting unit 141a performs control to decrease the opening degree of the outdoor expansion valve 36 by the feedback amount ΔF, and when the discharge temperature Td is higher than the target temperature. Then, control is performed to increase the opening of the outdoor expansion valve 36 by the feedback amount ΔF.

The opening adjustment of the outdoor expansion valve 36 based on the discharge temperature Td by the expansion adjusting unit 141a is executed at regular control time intervals (for example, every 10 seconds).

(2-1-1-2) Feedback Amount Changing Unit The feedback amount changing unit 141d rewrites the value of the feedback amount ΔF stored in the feedback amount storage area 142b. The feedback amount changing unit 141d changes the value of the feedback amount ΔF stored in the feedback amount storage area 142b, so that the expansion adjusting unit 141a controls the opening degree of the outdoor expansion valve 36 based on the discharge temperature Td of the compressor 31. When performing the adjustment control, the adjustment amount of the opening degree of the outdoor expansion valve 36 that the expansion adjusting unit 141a adjusts by one adjustment control is changed. The process of changing the feedback amount ΔF by the feedback amount changing unit 141d will be described later.

(2-1-2) Storage Unit (2-1-2-1) Feedback Amount Storage Area In the feedback amount storage area 142b, the expansion adjusting unit 141a is provided for the outdoor expansion valve 36 based on the discharge temperature Td of the compressor 31. When the opening degree is adjusted and controlled, an adjustment amount of the opening degree of the outdoor expansion valve 36, which is adjusted by the expansion adjusting unit 141a by one adjustment control, is stored as a feedback amount ΔF.

The feedback amount ΔF in the feedback amount storage area 142b is set to the first amount F1 or the second amount F2 by being changed by the feedback amount changing unit 141d. The second amount F2 is smaller than the first amount F1. For example, the first amount F1 is 5% and the second amount F2 is 3%. However, the numerical value quoted here is only an example and is not limited to this.

(2-1-3) Input Unit Since the input unit 43 is the same as that in the first embodiment, description thereof is omitted.

(3) Feedback amount changing process The feedback amount ΔF of the outdoor expansion valve 36 by the expansion adjusting unit 141a (the expansion adjusting unit 141a adjusts and controls the opening degree of the outdoor expansion valve 36 using the discharge temperature Td of the compressor 31). In this case, the change process of the adjustment amount of the outdoor expansion valve 36, which is adjusted by one adjustment control, will be described with reference to the flowchart of FIG. The process of changing the feedback amount ΔF is repeatedly performed during the operation of the air conditioner 110.

In step S201, the feedback amount changing unit 141d acquires the rotational speed N of the compressor 31 from the compressor control unit 41b. Thereafter, the process proceeds to step S202.

In step S202, the feedback amount changing unit 141d determines whether or not the rotation speed N of the compressor 31 acquired in step S201 is smaller than a threshold value N1 '.

The threshold value N1 ′ is defined as the first amount F1 that is the amount of adjustment of the opening of the outdoor expansion valve 36 by the expansion adjustment unit 141a when the rotation speed N of the compressor 31 is set to the threshold value N1 ′. However, control hunting is not caused and the value is determined to be as small as possible. The threshold value N1 'is determined based on the actual machine test result of the air conditioner 110 and the like.

If it is determined in step S202 that the rotation speed N of the compressor 31 is smaller than the threshold value N1 ', the process proceeds to step S203. On the other hand, if it is determined in step S2 that the rotation speed N of the compressor 31 is greater than or equal to the threshold value N1 ', the process proceeds to step S205.

In step S203, the feedback amount changing unit 141d determines whether or not the feedback amount ΔF stored in the feedback amount storage area 142b is the first amount F1. If it is determined that the feedback amount ΔF stored in the feedback amount storage area 142b is the first amount F1, the process proceeds to step S204. On the other hand, when it is determined that the feedback amount ΔF stored in the feedback amount storage area 142b is not the first amount F1 (the second amount F2), the process is terminated.

In step S204, the feedback amount changing unit 141d changes the feedback amount ΔF stored in the feedback amount storage area 142b to the second amount F2. Thereafter, the process ends.

In step S205, the feedback amount changing unit 141d determines whether or not the feedback amount ΔF stored in the feedback amount storage area 142b is the second amount F2. When it is determined that the feedback amount ΔF stored in the feedback amount storage area 142b is the second amount F2, the process proceeds to step S206. On the other hand, if it is determined that the feedback amount ΔF stored in the feedback amount storage area 142b is not the second amount F2 (is the first amount F1), the process is terminated.

In step S206, the feedback amount changing unit 141d changes the feedback amount ΔF stored in the feedback amount storage area 142b to the first amount F1. Thereafter, the process ends.

By performing the above processing, when the rotation speed N of the compressor 31 becomes smaller than the threshold value N1 ′, the expansion adjustment unit 141a controls the opening degree of the outdoor expansion valve 36 based on the discharge temperature Td of the compressor 31. When adjustment control is performed, the adjustment amount of the degree of opening of the outdoor expansion valve 36, which is adjusted by the adjustment control unit 141a once, becomes the second amount F2. That is, the feedback amount changing unit 141d determines the feedback amount of the outdoor expansion valve 36 by the expansion adjusting unit 141a when the rotation speed N of the compressor 31 is smaller than the threshold value N1 ′ from a value equal to or higher than the threshold value N1 ′. ΔF is changed from the first amount F1 to a second amount F2 smaller than the first amount F1.

On the other hand, when the rotation speed N of the compressor 31 is equal to or higher than the threshold value N1 ′, the expansion adjustment unit 141a adjusts and controls the opening degree of the outdoor expansion valve 36 based on the discharge temperature Td of the compressor 31. The adjustment amount of the degree of opening of the outdoor expansion valve 36, which is adjusted by the adjustment control unit 141a once, becomes the first amount F1. That is, the feedback amount changing unit 141d determines the feedback amount of the outdoor expansion valve 36 by the expansion adjusting unit 141a when the rotation speed N of the compressor 31 is changed from a value smaller than the threshold value N1 ′ to a value equal to or larger than the threshold value N1 ′. ΔF is changed from the second amount F2 to the first amount F1.

Thereby, in the low rotation speed area | region (rotation speed N <threshold value N1 ') of the compressor 31, it can suppress that the opening degree of the outdoor expansion valve 36 is adjusted excessively by one adjustment control, and control hunting is prevented. can do. On the other hand, when the rotation speed N of the compressor 31 is relatively large (when the rotation speed N ≧ the threshold value N1 ′), the outdoor expansion valve 36 is opened compared to when the compressor 31 is operated in the low rotation speed region. Since the degree is greatly changed, the opening degree of the outdoor expansion valve 36 can be quickly adjusted and controlled.

In particular, here, the rotation speed N of the compressor 31 is compared with the threshold value N1 ′, and the feedback amount ΔF is only switched between two values (first amount F1 and second amount F2) according to the comparison result. Therefore, the above effect can be realized with a simple configuration and easy processing.

(4) Features (4-1)
The air conditioning apparatus 110 of the present embodiment is a refrigeration apparatus that uses R32 as a refrigerant. The air conditioner 110 includes a compressor 31, a condenser (the indoor heat exchanger 21 or the outdoor heat exchanger 34), an outdoor expansion valve 36 as an expansion mechanism, and an evaporator (the outdoor heat exchanger 34 or the indoor heat exchange). 21), a discharge temperature sensor 51 as a temperature detecting unit, an expansion adjusting unit 141a, and a feedback amount changing unit 141d. The compressor 31 sucks the low-pressure refrigerant from the suction pipe 81, compresses the refrigerant, and discharges the high-pressure refrigerant. The condenser (the indoor heat exchanger 21 or the outdoor heat exchanger 34) condenses the high-pressure refrigerant discharged from the compressor 31. The outdoor expansion valve 36 expands the high-pressure refrigerant that has exited the condenser (the indoor heat exchanger 21 or the outdoor heat exchanger 34). The evaporator (the outdoor heat exchanger 34 or the indoor heat exchanger 21) evaporates the refrigerant expanded by the outdoor expansion valve 36. The discharge temperature sensor 51 detects the discharge temperature Td of the refrigerant discharged from the compressor 31. The expansion adjustment unit 141a performs adjustment control of the outdoor expansion valve 36 using the discharge temperature Td. The feedback amount changing unit 141d changes the feedback amount ΔF of the outdoor expansion valve 36 by the expansion adjusting unit 141a. The feedback amount changing unit 141d changes the feedback amount ΔF from the first amount F1 to the second amount F2 smaller than the first amount F1 when the rotational speed N of the compressor 31 becomes smaller than the threshold value N1 ′. .

Here, when the rotational speed N of the compressor 31 is smaller than the threshold value N1 ′, the feedback amount ΔF of the outdoor expansion valve 36 by the expansion adjustment unit 141a is a second amount smaller than the first amount F1 from the first amount F1. Changed to F2. Therefore, the expansion adjusting unit 141a does not excessively adjust the outdoor expansion valve 36 when the rotation speed N of the compressor 31 is small and the refrigerant circulation amount is small. As a result, even when the rotation speed N of the compressor 31 is small, the outdoor expansion valve 36 can be controlled promptly and appropriately without causing control hunting.

In particular, here, since the feedback amount ΔF of the outdoor expansion valve 36 is changed based on the comparison result between the rotational speed N of the compressor 31 and the threshold value N1 ′, the compression is performed with a simple configuration and easy processing. Even when the rotational speed N of the machine 31 is small, the outdoor expansion valve 36 can be appropriately controlled.

(4-2)
In the air conditioning apparatus 10 of the present embodiment, the feedback amount changing unit 141d changes the feedback amount ΔF from the second amount F2 to the first amount F1 when the rotation speed N of the compressor 31 is equal to or greater than the threshold value N1 ′. Change to

Here, when the rotational speed N of the compressor 31 is equal to or greater than the threshold value N1 ', the feedback amount ΔF of the outdoor expansion valve 36 is changed to the first amount F1 that is larger than the second amount F2. Therefore, when the refrigerant circulation amount is large and the rotation speed N of the compressor 31 is equal to or greater than the threshold value N1 ', the adjustment control of the outdoor expansion valve 36 can be performed quickly.

(5-1) Modification 2A
In the air conditioning apparatus 110 according to the above embodiment, the feedback amount ΔF of the outdoor expansion valve 36 by the expansion adjusting unit 141a is changed. In addition, the expansion adjustment is performed in the same manner as the air conditioning apparatus 10 according to the first embodiment. The control time interval of the unit 141a may also be changed.

(5-2) Modification 2B
In the above embodiment, the number of indoor units 20 is one, but a plurality of units may be used. The plurality of indoor units may each be provided with an indoor expansion valve as an expansion mechanism. In this case, the expansion adjustment unit 141a performs adjustment control of the plurality of expansion mechanisms (outdoor expansion valve and indoor expansion valve) using the feedback amount that is changed by the rotational speed N of the compressor 31 as described above. Anything to do.

(5-3) Modification 2C
In the said embodiment, although an expansion mechanism is the outdoor expansion valve 36, it is not limited to this. The expansion mechanism only needs to expand the high-pressure refrigerant that has exited the condenser (the indoor heat exchanger 21 or the outdoor heat exchanger 34) and adjust the pressure and flow rate of the refrigerant. The expansion adjusting unit 141a is not limited to the one that adjusts the opening degree of the outdoor expansion valve 36, and may be any unit that can adjust and control the pressure change and flow rate adjustment of the refrigerant by the expansion mechanism.

For example, the expansion mechanism may be a plurality of capillary tubes having different characteristics, and the expansion adjustment unit may change the capillary tube through which the refrigerant flows by controlling an electric valve. Also in this case, the feedback amount changing unit uses the expansion adjustment unit feedback amount when the rotation speed N of the compressor 31 is smaller than the threshold value N1 ′, and the rotation speed N of the compressor 31 is the threshold value N1 ′. What is necessary is just to be comprised so that it may become small compared with the amount of feedback in the above case.

(5-4) Modification 2D
In the above embodiment, when there is a difference between the discharge temperature Td measured by the discharge temperature sensor 51 and the target temperature, the expansion adjusting unit 141a can perform the outdoor expansion as long as the rotation speed N of the compressor 31 does not change. The opening of the valve 36 is configured to be adjusted by a feedback amount ΔF (first amount F1 or second amount F2) determined per one adjustment control, but is not limited thereto.

For example, the feedback amount ΔF may be changed depending on conditions other than the rotational speed N of the compressor 31. And if the operating conditions other than the rotation speed N of the compressor 31 are the same, the feedback amount change part 141d is based on the expansion adjustment part 141a when the rotation speed N of the compressor 31 becomes smaller than the threshold value N1 ′. What is necessary is just to comprise so that the feedback amount of the outdoor expansion valve 36 may be made small compared with the feedback amount of the outdoor expansion valve 36 when the rotation speed N of the compressor 31 is more than threshold value N1 '.

For example, specifically, the adjustment amount (that is, the feedback amount) of the degree of opening of the outdoor expansion valve 36 per adjustment control of the expansion adjusting unit 141a is the value of the discharge temperature Td measured by the discharge temperature sensor 51. It may be changed according to the temperature difference from the target value of the discharge temperature. If the temperature difference between the value of the discharge temperature Td measured by the discharge temperature sensor 51 and the target value of the discharge temperature is the same, the feedback amount changing unit 141d sets the rotation speed N of the compressor 31 to the threshold value N1. It suffices that the feedback amount of the outdoor expansion valve 36 by the expansion adjustment unit 141a when it becomes smaller than the feedback amount when the rotation speed N of the compressor 31 is equal to or greater than the threshold value N1 ′.

(5-5) Modification 2E
In the above embodiment, the feedback amount ΔF is adjusted by the expansion adjusting unit 141a once when the expansion adjusting unit 141a adjusts and controls the opening degree of the outdoor expansion valve 36 using the discharge temperature Td of the compressor 31. The amount of adjustment of the opening degree of the outdoor expansion valve 36 to be adjusted is not limited to this. For example, the feedback amount ΔF may be a refrigerant flow rate change amount that changes by changing the opening degree of the outdoor expansion valve 36.

(5-6) Modification 2F
In the above-described embodiment, the feedback amount ΔF of the outdoor expansion valve 36 by the expansion adjustment unit 141a depends on whether the rotation speed N of the compressor 31 is smaller than the threshold value N1 ′ of 1, and the first amount F1 and the second amount F2. However, it is not limited to this. A plurality of threshold values are prepared, and the feedback amount ΔF of the outdoor expansion valve 36 may be changed in multiple stages depending on whether or not it is smaller than each threshold value.

According to the present invention, in the refrigeration apparatus using R32 as the refrigerant, when the expansion mechanism is controlled using the discharge temperature of the compressor, even when the compressor is operated in a low rotation speed range, The expansion mechanism can be controlled promptly and appropriately.

10,110 Air conditioning equipment (refrigeration equipment)
21 Indoor heat exchanger (condenser, evaporator)
31 Compressor 34 Outdoor heat exchanger (evaporator, condenser)
36 Outdoor expansion valve (expansion mechanism)
41a, 141a Expansion adjustment unit 41c Time interval change unit 141d Feedback amount change unit 51 Discharge temperature sensor (temperature detection unit)
81 Suction pipe (suction channel)

JP 2012-122777 A

Claims

A refrigeration apparatus (10) that uses R32 as a refrigerant,
A compressor (31) for sucking low-pressure refrigerant from the suction flow path (81), compressing the refrigerant and discharging high-pressure refrigerant;
A condenser (21, 34) for condensing the high-pressure refrigerant discharged from the compressor;
An expansion mechanism (36) for expanding the high-pressure refrigerant exiting the condenser;
An evaporator (34, 21) for evaporating the refrigerant expanded by the expansion mechanism;
A temperature detector (51) for detecting the discharge temperature of the refrigerant discharged from the compressor;
An expansion adjustment unit (41a) that performs adjustment control of the expansion mechanism using the discharge temperature;
A time interval changing unit (41c) for changing a control time interval of the expansion adjusting unit;
With
The time interval changing unit changes the control time interval from a first time interval to a second time interval longer than the first time interval when the rotation speed of the compressor becomes smaller than a threshold.
Refrigeration equipment.
The time interval changing unit changes the control time interval from the second time interval to the first time interval when the rotation speed of the compressor is equal to or greater than the threshold.
The refrigeration apparatus according to claim 1.
A refrigeration apparatus (110) using R32 as a refrigerant,
A compressor (31) for sucking low-pressure refrigerant from the suction flow path (81), compressing the refrigerant and discharging high-pressure refrigerant;
A condenser (21, 34) for condensing the high-pressure refrigerant discharged from the compressor;
An expansion mechanism (36) for expanding the high-pressure refrigerant exiting the condenser;
An evaporator (34, 21) for evaporating the refrigerant expanded by the expansion mechanism;
A temperature detector (51) for detecting the discharge temperature of the refrigerant discharged from the compressor;
An expansion adjustment unit (141a) that performs adjustment control of the expansion mechanism using the discharge temperature;
A feedback amount changing unit (141d) for changing a feedback amount of the expansion mechanism by the expansion adjusting unit;
With
The feedback amount changing unit changes the feedback amount from a first amount to a second amount smaller than the first amount when the rotation speed of the compressor is smaller than a threshold value.
Refrigeration equipment.
The feedback amount changing unit changes the feedback amount from the second amount to the first amount when the rotation speed of the compressor is equal to or greater than the threshold value.
The refrigeration apparatus according to claim 3.