CN114761742A

CN114761742A - Control device for refrigeration cycle device, and refrigeration cycle device

Info

Publication number: CN114761742A
Application number: CN201980102602.9A
Authority: CN
Inventors: 松尾光晃; 石原宽也; 八代崇宪
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2019-12-04
Filing date: 2019-12-04
Publication date: 2022-07-15
Anticipated expiration: 2039-12-04
Also published as: JPWO2021111559A1; GB202205556D0; JP7246518B2; GB2604464B; WO2021111559A1; CN114761742B; GB2604464A

Abstract

A control device (110) is provided with a memory (112) for storing a target value of a physical quantity to be controlled, and a CPU (111). The CPU (111) is configured to execute the following processing: i) an abnormality detection process for detecting an abnormality of the electronic expansion valve (5) on the basis of the physical quantity and a target value stored in the memory (112); ii) a valve operation confirmation process of, when abnormality of the electronic expansion valve (5) is detected by the abnormality detection process, transmitting a command to change the opening degree to the electronic expansion valve (5) and determining whether or not a change corresponding to the command is observed in the physical quantity; and iii) a stopping process of stopping the refrigeration cycle apparatus (100, 200) when no change is observed in the physical quantity in the valve operation checking process.

Description

Control device for refrigeration cycle device, and refrigeration cycle device

Technical Field

The present invention relates to a control device for a refrigeration cycle apparatus and a refrigeration cycle apparatus.

Background

The detection of a failure of an electronic expansion valve used in a refrigeration cycle apparatus is disclosed in patent No. 3558182 (patent document 1). The refrigeration cycle device is provided with an abnormality detection means for monitoring whether or not an abnormality has occurred in the refrigeration cycle by inputting the temperature of each part of the refrigeration cycle, the outdoor temperature, and the indoor temperature.

Patent document 1: japanese patent No. 3558182

In the failure detection function of the electronic expansion valve disclosed in patent No. 3558182 (patent document 1), the degree of superheat at the outlet of the evaporator may deviate from a normal range due to sudden change in the heat load or temporary use outside the normal use range, and the failure detection function may be erroneously stopped due to erroneous detection.

Disclosure of Invention

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a control device for a refrigeration cycle apparatus, which reduces erroneous detection of a failure of an electronic expansion valve, and a refrigeration cycle apparatus including the control device.

The present disclosure relates to a control device for a refrigeration cycle device equipped with an electronic expansion valve. The control device is provided with: a memory for storing a target value of a physical quantity to be controlled, and a control unit. The control unit is configured to execute: i) an abnormality detection process of detecting an abnormality of the electronic expansion valve based on the physical quantity and a target value stored in the memory; ii) a valve operation confirmation process of, when abnormality of the electronic expansion valve is detected by the abnormality detection process, transmitting a command to change the opening degree to the electronic expansion valve and determining whether or not a change corresponding to the command is observed in the physical quantity; and iii) a stopping process of stopping the refrigeration cycle apparatus when no change is observed in the physical quantity in the valve operation checking process.

According to the refrigeration cycle apparatus of the present disclosure, it is possible to avoid a situation in which the refrigeration cycle apparatus is erroneously stopped by erroneously detecting an abnormality of the electronic expansion valve.

Drawings

Fig. 1 is a configuration diagram showing a configuration of a refrigeration cycle apparatus according to embodiment 1.

Fig. 2 is a flowchart for explaining the periodic control of the various electronic expansion valves performed by the control device 110.

Fig. 3 is a flowchart for explaining the control of the abnormality detection process in embodiment 1.

Fig. 4 is a flowchart showing details of the abnormal stop processing in step S106 in fig. 3.

Fig. 5 is a flowchart for explaining control of the refrigeration cycle apparatus according to modification 1 of embodiment 1.

Fig. 6 is a flowchart for explaining control of the refrigeration cycle apparatus according to modification 2 of embodiment 1.

Fig. 7 is a configuration diagram of a salt water cooler as a target apparatus of embodiment 2.

Fig. 8 is a flowchart for explaining control of the abnormality detection process in embodiment 2.

Fig. 9 is a flowchart for explaining control of the abnormal stop processing in step S216 in fig. 8.

Fig. 10 is a flowchart for explaining control of the abnormality detection process in modification 1 of embodiment 2.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Hereinafter, a plurality of embodiments will be described, but it is intended that the configurations described in the respective embodiments can be appropriately combined at the beginning of the application. In the drawings, the same or corresponding portions are denoted by the same reference numerals, and description thereof will not be repeated.

Embodiment 1.

The refrigeration cycle apparatus 100 shown in fig. 1 is specifically an air-cooled refrigerator equipped with a 2-stage compressor. The refrigeration cycle apparatus 100 includes: a cooling source unit 101, and a load unit 102 provided inside the refrigerated warehouse 25. The refrigeration cycle apparatus 100 is provided in the refrigerated warehouse 25. Since the air-cooled type is adopted, the cooling source unit 101 storing the compressor 1 and the air-cooled condenser 3 is installed outdoors.

In the following embodiments, a specific example of the refrigeration cycle apparatus is described as a refrigerating machine, but the technique related to suppressing erroneous detection of an expansion valve abnormality and suppressing abnormal stop described in the following embodiments can be applied to an air conditioner.

The cooling source unit 101 includes: the system includes a compressor 1, an oil separator 2, an air-cooled condenser 3, an intercooler 4, an oil cooler 7, an expansion valve 8 for intercooler, an expansion valve 9 for oil cooling, and an expansion valve 10 for motor cooling. These expansion valves are electronic expansion valves.

The load unit 102 includes a main liquid expansion valve 5 (electronic expansion valve), an evaporator 6, an evaporation pressure sensor 27, and a temperature sensor 28.

The compressor 1, the oil separator 2, the air-cooled condenser 3, the intercooler 4, the main liquid expansion valve 5, and the evaporator 6 are connected by a main flow refrigerant pipe 20. The motor cooler refrigerant pipe 23 branches off from the main flow refrigerant pipe 20 and is connected to the compressor 1 via the motor cooling expansion valve 10. The intercooler refrigerant pipe 21 branches from the main flow refrigerant pipe 20, and is connected to the compressor 1 via the intercooler expansion valve 8 and the intercooler 4. The oil cooler refrigerant pipe 22 branches from the main flow refrigerant pipe 20, and is connected to the compressor 1 via the oil cooling expansion valve 9 and the oil cooler 7. The oil supply pipe 24 is connected from the oil separator 2 to the compressor 1 via the oil cooler 7.

The cooling source unit 101 further includes temperature sensors 11, 15-19, pressure sensors 12-14, and a control device 110.

The temperature sensor 11 detects the temperature of the refrigerant sucked by the compressor 1. The pressure sensor 12 detects the pressure of the refrigerant sucked by the compressor 1. The pressure sensor 13 detects the pressure of the refrigerant sucked into the intermediate chamber of the compressor 1. The pressure sensor 14 detects the pressure of the refrigerant discharged from the compressor 1. The temperature sensor 15 detects the temperature of the refrigerant discharged from the compressor 1. The temperature sensor 16 detects the temperature of the liquid refrigerant flowing out of the first flow path outlet of the intercooler 4. The temperature sensor 17 detects the temperature of the gas refrigerant flowing out of the second flow path outlet of the intercooler 4. The temperature sensor 18 detects the temperature of the refrigerating machine oil flowing out of the oil cooler 7. The temperature sensor 19 detects the temperature of the gas refrigerant flowing out of the oil cooler 7. The temperature sensor 28 detects the temperature of the gas refrigerant at the outlet of the evaporator 6.

The blower of the air-cooled condenser 3, the blower of the evaporator 6, and the compressor 1 are driven by inverters, not shown. The control device 110 instructs the inverter of the operating frequency (rotational speed). The control device 110 stores the set temperature set by the user in the memory 112 via a remote controller not shown.

The control device 110 determines whether the refrigeration cycle apparatus 100 is operating or stopped by comparing the interior temperature detected by the interior temperature sensor 26 with the set temperature stored in the memory 112.

The above-described configuration is a specific example for explaining the refrigeration cycle device of the present embodiment, but the present invention is not limited to this.

The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 is separated from the refrigerator oil when passing through the oil separator 2. The gas refrigerant separated from the refrigerator oil flows into the air-cooled condenser 3.

In the air-cooled condenser 3, the outside air is heat-exchanged with the refrigerant by a blower driven by an inverter. As a result, the gas refrigerant is condensed into a liquid refrigerant.

The liquid refrigerant flowing out of the air-cooled condenser 3 is cooled to increase the degree of supercooling when passing through the intercooler 4, is decompressed to become a low-pressure two-phase refrigerant when passing through the main liquid expansion valve 5, and flows into the evaporator 6.

In the evaporator 6, the air in the refrigerator is heat-exchanged with the refrigerant by a blower driven by an inverter. As a result, the two-phase refrigerant evaporates into a gas refrigerant.

The gas refrigerant flowing out of the evaporator 6 is sucked by the compressor 1, and the refrigerant of the main flow refrigerant pipe 20 circulates once.

The intercooler 4 has: a first flow path through which the refrigerant in the main flow refrigerant pipe 20 flows, and a second flow path through which the refrigerant decompressed by the intermediate cooling expansion valve 8 flows. In the intercooler 4, the two-phase refrigerant flowing through the second flow path exchanges heat with the liquid refrigerant flowing through the main flow first flow path. The two-phase refrigerant having passed through the second flow path of the intercooler 4 is vaporized and flows into the intermediate chamber of the compressor 1 through the refrigerant pipe 21 for the intercooler.

In the oil cooler 7, the two-phase refrigerant decompressed by the oil cooling expansion valve 9 exchanges heat with the refrigerating machine oil flowing out of the oil separator 2. As a result, the refrigerating machine oil is cooled. In the oil cooler 7, the two-phase refrigerant is vaporized. The vaporized refrigerant passes through the oil cooler refrigerant pipe 22 and flows into the intermediate chamber of the compressor 1. On the other hand, the refrigerating machine oil cooled by the oil cooler 7 is supplied to the compressor 1 through the oil supply pipe 24.

The two-phase refrigerant decompressed by the motor cooling expansion valve 10 flows into the motor chamber of the compressor 1 to cool the motor, not shown.

The control device 110 includes a cpu (central Processing unit)111, a memory 112(rom (read Only memory) and ram (random Access memory), an input/output buffer (not shown) for inputting and outputting various signals, and the like. The CPU111 is a control unit (controller) that expands and executes a program stored in the ROM in the RAM or the like. The program stored in the ROM is a program in which processing steps of the control device 110 are written. The control device 110 executes control of each device in the refrigeration cycle apparatus 100 according to these programs. This control is not limited to software-based processing, and may be performed by dedicated hardware (electronic circuit).

The control device 110 controls the frequencies of the compressor 1, the blower of the air-cooled condenser 3, and the blower of the evaporator 6. Here, the "frequency" is a frequency of an inverter that drives a motor, and means a rotation speed of a motor that drives a compressor or a blower.

In the compressor 1, the controller 110 compares a target evaporation temperature stored in advance in the memory 112 with a saturation temperature equivalent value (evaporation temperature) of the evaporation pressure detected by the evaporation pressure sensor 27, and controls the frequency of the compressor 1 at regular time intervals. If the evaporation temperature is higher than the target evaporation temperature, the control device 110 increases the frequency of the compressor 1 to enhance the cooling capacity.

For the blower of the air-cooled condenser 3, the control device 110 calculates the target condensation temperature using the measured values of the outside air temperature and the like based on the calculation formula of the target condensation temperature stored in the memory 112. The control device 110 controls the frequency of the blower of the air-cooled condenser 3 at regular time intervals based on the difference between the target condensation temperature and the condensation temperature corresponding to the saturation temperature of the pressure detected by the pressure sensor 14. For example, the control device 110 increases the frequency of the blower when the condensing temperature is higher than the target condensing temperature, and decreases the frequency of the blower when the temperature is opposite to the target condensing temperature.

The control device 110 controls the frequency of the blower of the evaporator 6 based on the temperature in the refrigerator detected by the temperature sensor 26 in the refrigerator and the set temperature set by the user, for the blower of the evaporator 6. For example, the control device 110 normally operates the blower at a frequency of 60Hz, lowers the temperature in the refrigerator, and performs the energy saving operation with the frequency set to 30Hz when the temperature approaches the set temperature (temperature control stop temperature).

In the expansion valve 8 for intercooler, the control device 110 calculates the degree of superheat of the intercooler, which is the difference between the detection value of the intercooler outlet gas temperature detected by the temperature sensor 17 and the saturation temperature of the intermediate pressure detected by the pressure sensor 13. The control device 110 controls the opening degree of the expansion valve 8 for intermediate cooling at regular time intervals based on the difference between the degree of superheat and the target degree of superheat of the intermediate cooler stored in advance in the memory 112.

Regarding the expansion valve 9 for oil cooling, the control device 110 controls the opening degree of the expansion valve 9 for oil cooling at regular time intervals based on the difference between the fuel supply temperature, which is the detection value of the temperature sensor 18, and the target fuel supply temperature stored in the memory 112 in advance. Here, the controller 110 may control the opening degree of the oil cooling expansion valve 9 using the discharge temperature detected by the temperature sensor 15 instead of the supply oil temperature.

The control device 110 controls the opening degree of the motor cooling expansion valve 10 at regular time intervals based on the difference between the detected value of the motor chamber temperature sensor, not shown, and the target motor chamber temperature stored in the memory 112 in advance.

The control device 110 controls the opening degree of the main liquid expansion valve 5 at regular time intervals based on the difference between the evaporator outlet gas temperature detected by the temperature sensor 28 and the saturation temperature converted value (evaporation temperature) of the evaporation pressure detected by the evaporation pressure sensor 27, that is, the degree of superheat SHc of the refrigerant in the outlet portion of the evaporator 6.

Fig. 2 is a flowchart for explaining the periodic control of the various electronic expansion valves performed by the control device 110. The control device 110 performs regular control of the electronic expansion valve at regular time intervals, that is, at control cycles (on the order of several tens of seconds).

In step S1 of fig. 2, the control device 110 determines whether or not the timer T1 that counts the control cycle of the periodic control has reached a control cycle that is set in advance and stored in the memory 112. When the control cycle has come (yes in S1), the control device 110 advances the process to step S2.

In step S2, the control device 110 calculates the opening degree variation Δ Pls of the periodic control. In step S3, the controller 110 outputs Δ Pls calculated in step S2 to the pulse motor of the target electronic expansion valve.

By repeating the above, the control amount to be controlled by the electronic expansion valve can be maintained around the target value.

The control device of the refrigeration cycle apparatus controls the valve opening degree of each of the electronic expansion valves at regular time intervals (control cycles) so that a physical quantity (control quantity) to be controlled shifts near a target value. As a control method, proportional control for adjusting the valve opening degree in proportion to the difference between the current value and the target value of the controlled variable is relatively simple and is therefore often used. In the following description, the periodic control of each electronic expansion valve is also described on the premise of performing proportional control, but the periodic control may be performed using another control method.

The control method of each actuator described above is a general control method, and specific examples are shown for explaining the embodiments of the present application, but the present invention is not limited to this.

Here, a study is made about the main liquid expansion valve 5. The regular control that is regularly performed in the normal state will be briefly described with reference to fig. 2 with respect to the main liquid expansion valve 5. The control device 110 controls the opening degree of the main liquid expansion valve 5 at control intervals based on the degree of superheat SHc of the refrigerant in the outlet portion of the evaporator 6, which is a control amount of the periodic control, and the target degree of superheat SHcm stored in advance in the memory 112 during the operation of the compressor 1. For example, the control period is set to 30 seconds, and this value is set in advance and stored in the memory 112. The control cycle is timed by a timer T1 on the software of the control device 110. The control device 110 determines in step S1 whether the count of the timer T1 has reached 30 seconds. When the time counted by the timer T1 reaches 30 seconds (yes in S1), the control device 110 calculates the amount of change Δ Pls in the opening degree of the main liquid expansion valve 5 under the periodic control (step S2), and outputs the opening degree to the pulse motor of the main liquid expansion valve 5 (step S3). When a pulse corresponding to Δ Pls is applied to the pulse motor, the opening degree of the main liquid expansion valve 5 is changed by Δ Pls.

The periodic control shown in fig. 2 is continuously performed every control cycle during the operation of the compressor 1. The failure detection of the electronic expansion valve is performed in parallel with the periodic control.

However, in the failure detection function of the electronic expansion valve, the degree of superheat at the outlet of the evaporator may deviate from the normal range due to sudden change in the heat load or temporary use outside the normal use range, and the failure may be erroneously detected and stopped. For example, in the case of sudden change in the thermal load, a situation in which new cargo (cooled object) is carried into a refrigerated warehouse is considered. In this case, since the temperature in the storage increases, the degree of superheat at the outlet of the evaporator increases in the case of the evaporator, for example. If the heat capacity of the load is large, it takes time for the temperature to decrease, and the abnormal stop may occur by the abnormality detection process.

The normal usage range is specifically an operation range specified by a manufacturer of the refrigeration cycle apparatus, and the refrigeration cycle apparatus may be used in an operation state that is temporarily out of the usage range due to a user's use, a change in the outside air temperature, or the like. In addition, a sudden change in load may cause a temporary deviation in the range of use.

If the refrigeration cycle apparatus is abnormally stopped and an abnormality notification is given, the abnormal state is transmitted to the equipment side of the end user. As a result, if the equipment is stopped, the production using the equipment is stopped, or an operator is prompted to perform an inspection operation, this is disadvantageous to the end user.

In the present embodiment, such an abnormal stop due to erroneous detection is reduced, thereby avoiding erroneous detection and erroneous notification as much as possible.

Fig. 3 is a flowchart for explaining control of the abnormality detection process in embodiment 1. In fig. 3, the target of the abnormality detection processing is the main liquid expansion valve 5.

First, the control device 110 determines in step S101 whether the degree of superheat SHc is 30K (kelvin) or more or whether the degree of superheat SHc is 5K or less. Thus, the control device 110 detects an abnormal state in which the degree of superheat SHc, which is the control amount based on the main liquid expansion valve 5, has not reached the target value. In a normal state, the degree of superheat SHc of the refrigerant at the outlet of the evaporator 6 shifts around 10K. Therefore, if the degree of superheat SHc is 30K or more, the primary expansion valve 5 may be fixed at a position closer to the closing direction than the desired opening degree, and if the degree of superheat SHc is 5K or less, the primary expansion valve 5 may be fixed at a position closer to the opening direction than the desired opening degree. In the above case, abnormality of the main liquid expansion valve 5 is suspected.

However, a dead time (for example, 20 minutes) for counting the time by the timer T2 is set so that the abnormality of the main liquid expansion valve 5 is not determined by the temporary change in the superheat SHc. When the state in which the degree of superheat SHc enters the abnormality range of 30K or more or 5K or less continues for 20 minutes, the control device 110 determines that the main liquid expansion valve 5 is abnormal, and abnormally stops the refrigerator. The physical quantity used for the abnormality detection process to determine an abnormality is referred to as an abnormality determination quantity. Here, the abnormality determination amount is the degree of superheat SHc.

In step S101, if the degree of superheat SHc is in the abnormal range (yes in S101), the control device 110 advances the process to step S103 to start counting the time by the timer T2. If the timing is already in progress at this time, the control device 110 continues the timing.

When the degree of superheat SHc is in the normal range in step S101 (no in S101), the control device 110 advances the process to step S102, resets the timer T2, and returns the process. As a result, after a certain time has elapsed, the process returns to the beginning of fig. 3 again.

In step S104, the control device 110 determines whether the time counted by the timer T2 is 15 minutes. If the time counted by the timer T2 is 15 minutes (yes in S104), the control device 110 advances the process to step S107, and if the time counted is not 15 minutes (no in S104), the control device 110 advances the process to step S105.

In step S105, the control device 110 determines whether or not the time counted by the timer T2 is 20 minutes. Here, 20 minutes as a set value is a threshold value for determining that the main liquid expansion valve 5 is abnormal. If the time counted by the timer T2 is less than 20 minutes (no in S105), the control device 110 returns the process, and if the time counted by the timer T2 is 20 minutes or more (yes in S105), the control device 110 executes an abnormal stop process of the refrigeration cycle apparatus, which will be described later, in step S106.

In step S104, when the time counted by the timer T2 is 15 minutes, the control device 110 performs the valve operation confirmation process of the main liquid expansion valve 5 through the processes of step S107 and the processes after step S107. The valve operation confirmation processing is set to have higher priority than the regular control shown in fig. 2.

The regular control shown in fig. 2 is always executed, and the opening degree variation Δ Pls is calculated for each control cycle (timer T1). The control device 110 compares the priorities including the opening degree change amounts based on other processes such as the valve operation checking process, selects the opening degree change amount of the process having the higher priority, and outputs a command pulse to the main liquid expansion valve 5.

First, in step S107, the control device 110 fixes the respective frequencies of the compressor 1 driven by the inverter, the blower of the air-cooled condenser 3, and the blower of the evaporator 6 to the current frequency. The refrigerant state is made constant by making the frequency constant, thereby preventing erroneous determination by the valve operation check process after the passage.

In step S108, the control device 110 determines whether the current opening degree of the main liquid expansion valve 5 is the maximum opening degree (upper limit value) or the minimum opening degree (lower limit value). If yes is determined in step S108, the control device 110 sets the variable N to-1.0 in step S109. On the other hand, if no in step S108, the control device 110 sets the variable N to 2.0 in step S110. Here, the variable N is a variable used for operation of the operation amount of the main liquid expansion valve 5 in step S111. The change amount Δ Pls of the opening degree with respect to the operation in the periodic control immediately before the valve operation confirmation processing in step S107 and thereafter is an indication of an operation in the opposite direction when the variable N is a negative value, and an indication of an operation in the same direction when the variable N is a positive value.

When the variable N is a negative value, if the opening degree of the main liquid expansion valve 5 is changed abruptly, the degree of superheat SHc is changed in a more abnormal range, which is not preferable. Thus, in the case where the variable N is negative, for example, the variable N is limited to the range of-1.0. ltoreq. N.ltoreq.0.5 or so. On the other hand, when the variable N is a positive value, the variable N is in a range of, for example, 1.5. ltoreq. N.ltoreq.2.0 in order to rapidly change the degree of superheat SHc.

In step S111, the control device 110 stores the degree of superheat SHc at the current time in the memory 112. Further, the control device 110 calculates "the operation amount is Δ Pls × N" by using the variable N and the opening degree variation Δ Pls (positive and negative symbols) of the main liquid expansion valve 5 calculated by the periodic control. After outputting the operation amount to the main liquid expansion valve 5, the control device 110 resets the time counted by the timer T1 and restarts the time counting. This is to stop the calculation and output of the opening degree command by the periodic control and measure the time at which the transition of the normal determination amount is confirmed in step S113 by using the time measured by the timer T1.

In step S112, the control device 110 determines whether or not the count of the timer T1 has reached 30 seconds. When the count of the timer T1 reaches 30 seconds, the control device 110 advances the process to step S113. Since the priority of the valve operation confirmation processing in step S111 is set higher than that of the periodic control in fig. 2, the opening degree variation Δ Pls by the periodic control is not output.

Note that, although the timer T1 and the set value used for the periodic control are used for 30 seconds, other timers and other set values may be provided and used. When the timer T1 and other timers are used, it is necessary to prohibit the output of the opening degree variation Δ Pls by the periodic control or to stop the calculation of the periodic control in advance.

For example, if another timer is set to T5, S111 is changed to "inhibit pulse output by periodic control" from "reset timer T1& start of counting", and S112 is changed to "timer T5 ≧ 30 seconds? ", the same control can be realized.

In step S113, the control device 110 confirms the change in the superheat SHc after the operation of the main liquid expansion valve 5 in step S111. The physical quantity used in the valve operation confirmation process to determine whether the expansion valve is normal is referred to as a normal determination quantity. Here, the normal determination amount is the degree of superheat SHc. When the operation amount is positive, that is, when the main liquid expansion valve 5 is changed in the opening direction, the control device 110 determines whether the degree of superheat SHc has decreased. Conversely, when the operation amount is negative, that is, when the main liquid expansion valve 5 is changed in the closing direction, the controller 110 determines whether or not the degree of superheat SHc increases. When the main expansion valve 5 is normal, the superheat degree SHc decreases as the refrigerant flow rate increases when the opening degree in the opening direction is changed, and the superheat degree SHc increases as the opening degree in the closing direction is changed.

In the above description, all of the control amount, the abnormality determination amount, and the normality determination amount are the superheat degree SHc, but the normality determination amount may be replaced with the evaporation pressure as the detection value of the evaporation pressure sensor 27 or the evaporator evaporation temperature as the saturation temperature thereof. In this case, step S113 is replaced with "the evaporation pressure (evaporation temperature) increases when the opening direction of the main liquid expansion valve 5 changes, or the evaporation pressure (evaporation temperature) decreases when the closing direction of the main liquid expansion valve 5 changes".

If the determination in step S113 is negative, the main liquid expansion valve 5 is abnormal. In this case, the control device 110 returns the process. On the other hand, if it is determined yes in step S113, the main liquid expansion valve 5 is normal. In this case, the control device 110 advances the process to step S114, and resets the count of the timer T2.

By resetting the timer T2 in step S114, the abnormality detection processing (S101, S103 to S105) of the main liquid expansion valve 5 is terminated. When the condition of step S101 is satisfied again (yes in S101), in step S103, the control device 110 restarts counting the time by the timer T2.

Fig. 4 is a flowchart showing details of the abnormal stop processing in step S106 in fig. 3. The abnormal stop processing is processing for stopping the supply of cold and heat by stopping the refrigerator abnormally, and notifying the user or the user's equipment of the abnormality. The user's equipment is, for example, a centralized monitoring device for monitoring a refrigerating and air-conditioning apparatus (a device for monitoring the current state of a refrigerator or an air-conditioning apparatus by a computer, a touch panel type monitor, or the like, and performing setting temperature change, temperature, pressure, or other data recording, or the like), and end-user production equipment (a food production line, an environmental test apparatus, a chemical plant, or the like).

First, in step S121, the control device 110 turns on an abnormal lamp (not shown) provided in the control panel. Then, the control device 110 displays the content of the abnormality (name of the abnormality) on a display (a liquid crystal panel or the like) and outputs an abnormality signal to the user's equipment.

In step S122, the control device 110 stops each device of the refrigeration cycle apparatus. Specifically, the control device 110 sends a stop command to an inverter (not shown) that drives the blower of the compressor 1, the air-cooled condenser 3, and the blower of the evaporator 6, and stops them. At the same time, the control device 110 stops (closes) various solenoid valves and various electronic expansion valves provided in the refrigeration cycle apparatus.

Further, the processes of step S121 and step S122 are sequentially executed in software, but appear to be executed simultaneously in the human sense of time.

In step S123, the control device 110 resets each timer used in the control flow of fig. 3. Subsequently, the control device 110 starts to restart the counting of the limit time. The restart limit time is a start prohibition time from when the compressor 1 is stopped to when it is restarted, and the refrigeration cycle apparatus cannot be restarted until the restart limit time elapses.

The above-described periodic control (S1 to S3), the abnormality detection processing (S101, S103 to S105), and the valve operation confirmation processing (S107 to S114) with respect to the main liquid expansion valve 5 are executed independently of each other. During the operation of the compressor 1, the opening degree of the main liquid expansion valve 5 is periodically controlled and adjusted, and if the abnormality determination amount (here, the same as the control amount) deviates from the target value even in this way and enters the abnormality range, abnormality detection processing is executed. If the abnormality determination amount continues to stay within the abnormality range, it is determined that the expansion valve is abnormal by the abnormality detection processing, and the refrigeration cycle apparatus is abnormally stopped by the abnormality stop processing.

However, if the start condition of the valve operation checking process is satisfied during the operation of the abnormality detection process, the valve opening degree is operated by the valve operation checking process, and as a result, if the normality determination amount (here, the same as the control amount) shows a reasonable change, the valve operation checking process determines that the expansion valve is normal, and the abnormality detection process ends, and the abnormal stop is not performed.

As described above, in the refrigeration cycle apparatus according to embodiment 1, before the abnormality detection process determines that the main liquid expansion valve 5 is abnormal and the refrigeration cycle apparatus is abnormally stopped, the valve operation confirmation process is performed to confirm whether or not the electronic expansion valve is normal. For example, when the temperature in the interior of the cabinet is high, the main liquid expansion valve 5 may be normal but the superheat SHc may exceed 30K shortly after the start of cooling. In such a case, even if the operation state temporarily deviates from the normal range, the refrigeration cycle apparatus may not be stopped. That is, the supply of cold and hot water is continued, and unnecessary abnormality notification to the user's equipment is not required.

When the current opening degree of the main liquid expansion valve 5 is the maximum opening degree (upper limit value) or the minimum opening degree (lower limit value), the variable N is set to negative. In this case, since the main liquid expansion valve 5 changes its opening degree in a direction opposite to the periodically controlled opening degree changing direction, there is a possibility that foreign matter caught in the drive portion of the main liquid expansion valve 5 is removed, and in this case, an effect of returning the operation of the main liquid expansion valve 5 to normal is obtained.

Further, when the current opening degree of the main expansion valve 5 is not the maximum opening degree (upper limit value) or the minimum opening degree (lower limit value), the variable N is set to about 1.5 to 2, and therefore, a command value is output to be larger than the amount of change in the periodically controlled opening degree, and if the main expansion valve 5 is normal, the degree of superheat SHc can be changed rapidly (largely), and there is a possibility that the degree of superheat SHc enters a normal range.

Modification 1 of embodiment 1.

When a small foreign object is caught in the drive portion of the electronic expansion valve, the actual valve opening degree cannot be changed, and therefore the control amount may not be controlled to be close to the target value. When the control amount deviates from the target value, the expansion valve opening degree is continuously changed in one direction in the periodic control in order to approach the target value. Namely, there is a fear that: since the force in one direction is continuously applied to the driving unit and the foreign matter remains stuck, the abnormality detection process determines that the electronic expansion valve is abnormal and stops abnormally.

Regarding the failure caused by the foreign matter, for example, the following 3 cases are assumed.

First, foreign matter is caught at a contact portion between the male screw and the female screw of the expansion valve. The rod for adjusting the opening degree of the valve is an external thread, and the external thread is engaged with an internal thread fixed inside the expansion valve in the refrigerant. The male screw is fixed to the magnet, and when the magnet is rotated by a pulse, the male screw moves up and down by the screw mechanism to change the valve opening.

If the state in which the controlled variable deviates from the target value continues, the control device attempts to continue operating the expansion valve opening in one direction. For example, in the case of the degree of superheat, if the current value is larger than the target value, the output pulse is continued so as to increase the expansion valve opening degree.

Then, the male screw and the female screw are biased in one direction (a surface on one side of the screw), and the foreign matter is retained. Therefore, by temporarily operating the valve operation confirmation process in the opposite direction, the magnitude of the play (clearance) between the threads of the male thread and the female thread is separated, and no force is applied to the foreign matter (pressure is applied to the surface of the thread on the opposite side to the former side), so that the foreign matter may be washed away by the refrigerant and removed.

Second, the external thread and the internal thread are fixed to each other in order to freeze moisture in the refrigerant. In this case, the expansion valve may be operated in the reverse direction for a while to peel off the ice particles.

In the case 3, sludge or the like blocks the hole of the expansion valve. There is a possibility of flowing to the downstream side by operating the valve in the opening direction.

In the modification of embodiment 1, the electronic expansion valve is temporarily driven in the direction opposite to the periodic control, so that the electronic expansion valve is returned to the normal state in an effort.

Fig. 5 is a flowchart for explaining control of the refrigeration cycle apparatus according to modification 1 of embodiment 1. The flowchart shown in fig. 5 is the flowchart of embodiment 1 shown in fig. 3, in which steps S104, S107, and S110 are deleted, and steps S131 and S132 are added. The same processing as in fig. 3 is denoted by the same reference numerals, and description thereof is not repeated. Note that there is no change in the aspect that the target to which the abnormality detection processing is applied is the main liquid expansion valve 5.

In fig. 3, the valve operation confirmation process is executed when the timer T2 of step S104 reaches 15 minutes. In contrast, in fig. 5, the valve operation confirmation process is executed when the timer T2 of step S105 reaches 20 minutes before and the current opening degree of step S108 reaches the maximum opening degree (upper limit value) or the minimum opening degree (lower limit value). This is because if the degree of superheat SHc falls within the abnormal range and the current opening degree reaches the maximum opening degree or the minimum opening degree, abnormality of the main liquid expansion valve 5 is suspected. Thus, here, an example of the timing of starting the determination valve operation checking process is different from that in fig. 3.

In fig. 5, a timer T3 is provided, and the control device 110 starts counting the time of the timer T3 in step S131, and waits until a predetermined time, for example, 20 seconds, has elapsed in step S132. This is considered to be the time until the refrigerant state is stabilized after the frequencies of the blower and the compressor are fixed to a constant value. In fig. 3, an example of a simple embodiment is shown, but in fig. 5, step S132 is provided. Thus, for example, in the case where the valve operation confirmation process of the main liquid expansion valve 5 is started in the middle of changing the frequency in the periodic control of the frequency of the compressor, the valve operation confirmation process is easily performed at the time of the transient change.

In fig. 5, unlike fig. 3, the variable N takes only a negative value (step S109). The effect of removing foreign matter caught in the drive portion of the main liquid expansion valve 5 is addressed by changing the opening degree in the direction opposite to the direction indicated by Δ Pls in the periodic control, regardless of the current opening degree.

Modification 2 of embodiment 1.

Modification 2 of embodiment 1 shows that the same false detection prevention of abnormality as in embodiment 1 can be applied to the oil cooling expansion valve 9.

In the flowchart shown in fig. 6, steps S101, S102, S104, S108, S109, and S111 to S113 are deleted and steps S141 to S149 are added to the flowchart shown in fig. 3 adopted in embodiment 1. Note that the same processing as in fig. 3 is denoted by the same reference numerals, and description thereof is not repeated.

As shown in S1 of fig. 2, the controller 110 periodically controls the oil cooling expansion valve 9 at a 45-second cycle measured by the timer T1. In the periodic control of the expansion valve 9 for oil cooling, the opening degree control is performed based on the difference between the oil supply temperature Toil detected by the temperature sensor 18 and the target oil supply temperature stored in the memory 112 in advance. At this time, the fuel supply temperature is a control amount.

In the abnormality detection process of the oil cooling expansion valve 9 shown in fig. 6, an example is shown in which only the fixation in the closing direction with respect to the required opening degree is detected. Specifically, when the state in which the oil supply temperature is, for example, 50 ℃ or higher in step S141 continues for 20 minutes in step S105, the controller 110 determines that the oil cooling expansion valve 9 is abnormal. The abnormality determination amount is the fuel supply temperature.

In step S149 of the valve operation checking process, the fuel supply temperature Toil detected by the temperature sensor 18 is used as the normal determination amount to determine.

Here, the control amount, the abnormality determination amount, and the normality determination amount are set to the fuel supply temperature Toil, but these may be set to the discharge temperature Td detected by the temperature sensor 15. This is because the discharge temperature Td changes due to a change in the temperature of the refrigeration machine oil supplied to the compressor 1 when the opening degree of the oil cooling expansion valve 9 changes. In the case where the discharge temperature Td is used, in step S141 of the abnormality detection processing, it is determined that there is an abnormality when the discharge temperature Td is, for example, 80 ℃.

Further, an example in which the valve operation confirmation processing is performed 2 times is shown in the flowchart of fig. 6. Therefore, a counter C1 for counting the number of times the valve operation confirmation process is performed is added and used in step S145. That is, in step S145, it is determined whether or not the counter C1 is 1 or less. If C1 is not more than 1 (yes in S145), that is, if the valve operation confirmation process is not performed or the valve operation confirmation process is performed 1 time, the valve operation confirmation process is performed in step S107 and after step S107. If C1 > 1 (no in S145), the control device 110 returns the process because the valve operation check process has been performed 2 times.

On the other hand, in the case where the determination in step S141 is no, that is, in the case where the fuel supply temperature Toil is less than 50 ℃ and enters the normal range, the count of the counter C1 is reset in step S142. If it is determined yes in step S105, the control device 110 resets the counter C1 because the refrigeration cycle apparatus is abnormally stopped by the abnormality detection processing.

In step S146, it is determined whether or not the current opening degree of the oil cooling expansion valve 9 is the maximum opening degree (upper limit value). Unlike step S108 of fig. 3, whether or not the minimum opening degree (lower limit value) is determined is not because only the closed state is considered in step S141. That is, when the expansion valve 9 for oil cooling is fixed in a state in which the opening degree is small, the opening degree change amount Δ Pls is set to a positive amount in order to approach the target value in the periodic control, and the opening degree is intended to be changed in the opening direction. This is because, when the state in which the oil supply temperature Toil is high continues, the command value for the opening degree of the final oil cooling expansion valve 9 reaches the maximum opening degree (upper limit value).

In step S147, the process is almost the same as that in step S111 of fig. 3, but the amount of normal determination is different, and therefore the stored physical quantity is the fuel supply temperature Toil. Since the valve operation confirmation processing is performed, the count of the counter C1 is increased by 1.

Since the control cycle of the periodic control of the expansion valve 9 for oil cooling is 45 seconds, in step S148, the value of the timer T1 is compared with 45 seconds.

When the opening degree of the oil cooling expansion valve 9 is changed in the opening direction, the oil supply temperature Toil decreases when the oil cooling expansion valve 9 operates normally. In step S149, the presence or absence of the operation of the oil cooling expansion valve 9 is determined based on this principle.

As described above, in modification 2 of embodiment 1, by performing the valve operation confirmation processing of steps S107 to S149 2 times, it is possible to change the opening degree of the target expansion valve more, and there is an effect that the change in the normality determination amount is easily promoted.

Further, when there is a variation in the thermal load before and after the time when the valve operation confirmation process is performed, it may not be possible to accurately determine whether or not the expansion valve is normal, but by performing the valve operation confirmation process 2 times, erroneous determination can be suppressed.

Further, although embodiment 1 shows a configuration in which the refrigerator shown in fig. 1 is also provided with a load-side device (such as the evaporator 6), the control related to the suppression of the stop of the expansion valve based on the abnormality detection shown in the present embodiment can be applied to a condensing unit not having the main liquid expansion valve 5 and the evaporator 6. In this case, the electronic expansion valve in the condensing unit is the subject of application of this control.

Further, the present invention can also be applied to control of an electronic expansion valve configured as a refrigerator by combining a condensing unit and a load-side controller. The load-side controller is electrically connected to the main liquid expansion valve 5, the evaporator 6, the interior temperature sensor 26, and the condensing unit, which are load-side devices, and controls the condensing unit and the load-side devices based on the detection value and the set temperature of the interior temperature sensor 26. In this case, the load-side controller applies the abnormality detection processing to the main liquid expansion valve 5, and the control device of the condensing unit can apply the abnormality detection processing to the electronic expansion valve provided in the condensing unit.

Embodiment 2.

Embodiment 2 shows a case where the abnormality detection processing can be applied to other expansion valves of other types of refrigeration cycle devices, and is similar to the modification of embodiment 1. Specifically, in embodiment 1, an application example to a refrigerator is described, but in embodiment 2, an application example to a salt brine cooler is described.

Fig. 7 is a configuration diagram of a salt water cooler as a target apparatus of embodiment 2. The salt-pickling cooler 200 includes a constant-speed compressor 31, an oil separator 2, a water-cooled condenser 32, an intercooler 4, a main liquid expansion valve 5, an expansion valve 8 for intercooler, an expansion valve 10 for motor cooling, a brine cooler 34, and a water-cooled oil cooler 38.

The main flow refrigerant pipe 20, the intercooler refrigerant pipe 21, the motor cooler refrigerant pipe 23, the oil supply pipe 24, the cooling water pipe 33, and the brine pipe 35 connect the above components.

The salt pickling cooling machine 200 further comprises temperature sensors 11, 15-18, 28, 36, 37, pressure sensors 12-14, an evaporation pressure sensor 27 and a control device 110.

Temperature sensors

36, 37 detect the temperature of the brine at the brine inlet and outlet of the brine cooler 34, respectively.

Note that the same devices as those in fig. 1 are denoted by the same reference numerals, and description thereof will not be repeated. The pump for pumping the cooling water and the brine is not shown because it is a field device.

The constant speed compressor 31 is not variable in speed as in the inverter drive, and is operated at a constant speed by a commercial power source such as 50Hz or 60Hz, for example. The constant speed compressor 31 includes a mechanical capacity control mechanism (not shown) for controlling the discharge amount. The capacity control means can change the operating capacity by bypassing a part of the compressed gas of the constant speed compressor 31 to the suction side in the compressor and reducing the discharge amount.

The controller 110 controls the capacity control mechanism based on, for example, the difference between the brine outlet temperature detected by the temperature sensor 37 and the target brine outlet temperature stored in the memory 112 in advance. When the brine outlet temperature is higher than the target brine outlet temperature, the controller 110 increases the capacity of the capacity control mechanism to increase the compressor discharge amount.

The water-cooled condenser 32 is a heat exchanger that condenses the refrigerant gas by exchanging heat between the cooling water flowing through the cooling water pipe 33 and the high-temperature and high-pressure refrigerant gas discharged from the constant-speed compressor 31.

The cooling water having a temperature increased by the water-cooled condenser 32 releases heat in a cooling tower of the on-site equipment not shown, and then returns to the water-cooled condenser 32. The cooling water is pumped through the cooling water pipe 33 by a cooling water pump of the field equipment, not shown, and circulates through the water-cooled condenser 32 and the cooling tower. The cooling water pump is operated and stopped in conjunction with the operation and stop of the salt brine cooler 200. In this case, the following control may be adopted: during several tens of seconds after the stop of the fixed speed compressor 31, the cooling water pump is continuously operated and then stopped.

The brine cooler 34 is a heat exchanger that exchanges heat between the two-phase refrigerant that has been depressurized by the main expansion valve 5 to have a low pressure and a low temperature and brine (antifreeze) flowing through the brine pipe 35. The brine is pumped by a brine pump not shown. In the use of the salt cooler, the brine pump is operated substantially without stopping even when the compressor is stopped.

The water-cooled oil cooler 38 is a heat exchanger that cools the refrigeration machine oil by exchanging heat between the refrigeration machine oil flowing from the oil separator 2 and the cooling water flowing through the cooling water pipe 33. The cooling water pipe 33 of the water-cooled oil cooler 38 merges with the cooling water pipe 33 of the water-cooled condenser 32, and is connected to a cooling tower (not shown).

Shell and tube type or plate type heat exchangers are used for the water-cooled condenser 32, the brine cooler 34, and the water-cooled oil cooler 38.

The controller 110 in fig. 7 has a function of outputting an operation/stop command to a cooling water pump and a brine pump, not shown, in addition to controlling the brine cooling machine 200. For example, the control device 110 uses voltage contacts to output an operation command and a stop command to a pump of the field device.

In the salt bath cooler 200 according to embodiment 2, the control method of the main liquid expansion valve 5, the expansion valve 8 for intermediate cooling, and the expansion valve 10 for motor cooling is the same as that of embodiment 1, and therefore, the description thereof will not be repeated.

Fig. 8 is a flowchart for explaining control of the abnormality detection process in embodiment 2. In fig. 8, the target of the abnormality detection process is also described as the main liquid expansion valve 5. Here, an example in which the control cycle of the periodic control of the main liquid expansion valve 5 is 30 seconds will be described.

In the example shown here, the abnormality detection processing of the main liquid expansion valve 5 is configured to: when the degree of superheat SHc is detected to be 35K or more or 3K or less in step S204, the routine proceeds to step S216, and an abnormal stop is immediately performed.

First, in step S201, the control device 110 determines whether the degree of superheat SHc is 27K or more, or whether the degree of superheat SHc is 7K or less. 27K and 7K used in step S201 are second thresholds. The second threshold value is a value shifted to the normal side with respect to the first threshold value (35K and 3K) used in the abnormality detection processing in step S204, and is stored in advance in the memory 112 of the control device 110.

If it is determined yes in step S201, the process proceeds to step S203. In step S203, the control device 110 determines whether or not the counter C1 is 0 (not implemented). The counter C1 is a counter that counts the number of times the valve operation confirmation process is performed. If not (yes in S203), control device 110 advances the process to step S205. On the other hand, if the execution is completed 1 time (no in S203), the control device 110 advances the process to step S204.

In step S205, the control device 110 multiplies the current opening degree of the main liquid expansion valve 5 by a ratio (for example, 15%) previously set and stored in the memory 112 to calculate the opening degree variation δ Pls.

In step S206, the control device 110 compares the δ Pls calculated in step S205 with the Δ Pls calculated in the periodic control. If δ Pls is small (yes in S206), the control device 110 substitutes the value of δ Pls into Δ Pls in step S207. The sign of the sign remains the same as Δ Pls at this time.

In step S208, the controller 110 fixes the capacity of the capacity control mechanism (capacity control valve) of the fixed-speed compressor 31 to a value at that time.

In step S209, it is determined whether the current opening degree of the main liquid expansion valve 5 is the maximum opening degree or the minimum opening degree. If it is determined yes in step S209, control device 110 sets variable N to-1.0 in step S210. On the other hand, if it is determined as no in S209, control device 110 sets variable N to 1.0 in step S211.

Since Δ Pls calculated in steps S205 to S207 is used with the Δ Pls being maintained, the variable N is set to 1.0 in size in steps S210 and S211 and used as a variable for changing only the sign.

In step S212, the control device 110 stores the evaporation pressure LP (normality determination amount) detected by the evaporation pressure sensor 27 at that time in the memory 112. Then, the control device 110 calculates the operation amount "Δ Pls × N" in the valve operation confirmation process, and outputs a command corresponding to the operation amount to the main liquid expansion valve 5. Then, the controller 110 increments the count of the counter C1 by 1, resets the count of the timer T1, and then starts the count of the timer T1.

In step S213, the control device 110 determines whether or not the timer T1 has reached the control cycle for 30 seconds. If the result is reached (yes in S213), control device 110 advances the process to step S214.

In step S214, the control device 110 confirms whether or not the evaporation pressure LP, which is a normal determination amount, has changed in accordance with the opening degree change command output in step S212. When the main liquid expansion valve 5 is changed in the opening direction, it is checked whether the evaporation pressure LP is increased, and when the main liquid expansion valve 5 is changed in the closing direction, it is checked whether the evaporation pressure LP is decreased. If yes in step S214, the control device 110 determines that the main liquid expansion valve 5 is normal, and returns the process. At this point, even if step S201 is satisfied, since counter C1 is 1, no is branched to step S203, and the valve operation confirmation processing after step S208 and step S208 is not performed.

If no in step S214, the control device 110 determines that the main liquid expansion valve 5 is abnormal, resets the counter C1 in step S215, and abnormally stops the salt brine cooler in the abnormal stop process in step S216.

If no is branched in step S201, that is, if the degree of superheat SHc is in the normal range, the control device 110 resets the counter C1 in step S202, and returns the process. Here, since the counter C1 is reset to 0, if the process branches yes again in step S201, the process also branches yes in step S203, and the valve operation confirmation process after step S208 and step S208 is executed again.

Fig. 9 is a flowchart for explaining control of the abnormal stop process in step S216 in fig. 8.

In step S221, the control device 110 turns on an abnormality lamp, not shown, and displays the abnormality content on a display, not shown. The control device 110 outputs an abnormality signal to the outside such as a field device.

In step S222, the control device 110 stops each equipment of the salt cooling machine. Typically, the control device 110 stops the constant speed compressor 31, and further stops (closes) various solenoid valves and various electronic expansion valves.

In step S223, the control device 110 resets each timer used in the flowchart of fig. 8, and starts counting the restart limit time. Then, the control device 110 starts the timer T4 for delaying the stop of the pump.

In step S224, the control device 110 determines whether the timer T4 has reached 60 seconds. If the command has been received, the control device 110 turns off the external output pump operation command and stops the pump in step S225.

As described above, as the abnormality detection process of the electronic expansion valve, even when the abnormality detection process is configured to immediately perform the abnormal stop when the abnormality determination amount satisfies the threshold value (first threshold value) of the abnormality range, the valve operation confirmation process can be performed by providing the second threshold value.

The second threshold value is set closer to the normal range than the first threshold value, and therefore, the valve operation confirmation process can be performed when the valve operation check process is performed in a relatively normal operating state before the abnormal state is reached.

In a situation where the abnormality determination amount enters the abnormality range, the opening degree variation amount in the periodic control has a tendency to become gradually larger every elapsed control period. In embodiment 2, the operation amount of the expansion valve outputted by the valve operation checking process is compared with the amount of change in the opening degree of the periodic control calculated by multiplying the current opening degree by a predetermined ratio, and the smaller one is outputted. Thus, when the expansion valve is normal, it is possible to prevent sudden changes in the operating state due to large changes in the actual opening degree of the expansion valve, and abnormal stop can be performed when the condition of step S204 is satisfied.

Modification 1 of embodiment 2.

Modification 1 of embodiment 2 shows that the abnormality detection processing can be applied to the intermediate cooling expansion valve 8.

The superheat SHe is used as a control amount for the periodic control of the expansion valve 8 for intermediate cooling. The superheat SHe is a difference between the outlet gas temperature of the intercooler 4 detected by the temperature sensor 17 and a saturation temperature conversion value of the intermediate pressure detected by the pressure sensor 13.

The controller 110 controls the opening degree of the expansion valve 8 for intercooler based on the difference from the target superheat degree of the intercooler stored in advance in the memory 112 for the superheat degree SHe by the same control as the flowchart shown in fig. 2. The control period of the periodic control is, for example, 30 seconds.

In the compressor operation, in step S1 of fig. 2, the controller 110 determines whether or not the timer T1 is 30 seconds. When the timer T1 reaches 30 seconds, the controller 110 calculates the opening degree change amount Δ Pls (step S2), and outputs the opening degree change amount Δ Pls to the intermediate cooling expansion valve 8.

In the abnormality detection process, the degree of superheat SHe is similarly used as the abnormality determination amount, and it is determined that the abnormality is caused by the state in which the degree of superheat SHe is 5K or less continuing for 20 minutes.

Fig. 10 is a flowchart for explaining control of the abnormality detection process in modification 1 of embodiment 2. In fig. 10, the same processes as those in fig. 8 are denoted by the same reference numerals, and description thereof will not be repeated.

In step S231, the control device 110 determines whether the degree of superheat SHe is 5K or less. If the determination in step S231 is yes, the process proceeds to step S233, and if the determination is no, the process proceeds to step S232. Here, the abnormality detection process is performed to detect only a case where the expansion valve 8 for intermediate cooling is fixed at a position closer to the opening direction than necessary.

In step S233, the control device 110 starts counting of the timer T2. If the time measurement is already in progress in step S233, control device 110 continues the time measurement. The timer T2 is a timer for counting a dead time of the abnormality detection processing.

Then, the control device 110 determines in step S234 whether or not the value of the timer T2 is 20 minutes or more, and if the determination result is yes, the process proceeds to step S208, and if not, the process proceeds to return.

In step S208, the controller 110 fixes the capacity of the capacity control mechanism (capacity control valve) of the constant-speed compressor 31 to a value at that time.

Further, in step S235, the controller 110 determines whether or not the current opening degree of the expansion valve 8 for intercooler is equal to or greater than (minimum opening degree + | Δ Pls |). If the determination result is yes, the control device 110 advances the process to step S236, and if not, advances the process to step S237.

Since only the fixation of the opening direction side is detected in step S231, the control device 110 determines whether the current opening degree is in the vicinity of the minimum opening degree in step S235. In the case of the opening direction side being fixed, since the opening degree is larger than the required opening degree, the opening degree is changed in a direction in which the superheat degree SHe is decreased and Δ Pls calculated by the periodic control is negative, that is, in a direction in which the expansion valve is closed. Thus, when the state in which the degree of superheat SHe is small continues, the command value for the intermediate cooling expansion valve 8 finally reaches the minimum opening degree. When the current opening degree is the minimum opening degree, the opening degree cannot be further reduced, and therefore the current opening degree is compared with (minimum opening degree + | Δ Pls |). If there is a margin of Δ Pls or more before the minimum opening degree, the variable N is set in step S236, and if there is no margin, the variable N is set in step S237.

The variable N uses two variables N (1) and N (2). In step S236, the control device 110 sets the variable N to N (1) — 0.5 and N (2) — 2.0. In step S237, the control device 110 sets the variable N to-0.5 for N (1) and-0.5 for N (2). The two variables N are provided first to change the opening degree in a direction opposite to the opening degree change direction of the periodic control using N (1). If a situation occurs in which foreign matter is caught in the drive portion of the expansion valve 8 for intermediate cooling and is unable to operate normally, the drive portion of the expansion valve is temporarily operated in the opposite direction, thereby providing an effect of removing the foreign matter. In the periodic control, the opening degree is continuously reduced for each control cycle, and the driving portion of the expansion valve is continuously biased in the closing direction, so that the trapped foreign matter is not easily removed. Next, N (2) is used to perform a second pulse output.

In step S238, the control device 110 stores the current value of the degree of superheat SHe as the normal determination amount. Further, the controller 110 outputs a pulse of "Δ Pls × N (1)" to the intermediate cooling expansion valves 8 and then outputs a pulse of "Δ Pls × N (2)". When the opening degree output for 2 times has passed through step S236, the former is a change in the opening direction, and the latter is a change in the closing direction. When step S237 is passed, the on direction changes 2 times. Subsequently, the controller 110 resets the timer T1 to restart the timer.

In step S213, the control device 110 determines whether or not the timer T1 has reached the control cycle for 30 seconds. In step S213, if 30 seconds have elapsed, the control device 110 advances the process to step S239.

In step S239, after using the change in the opening degree of N (2) in step S238, the control device 110 checks whether or not the superheat SHe shows a reasonable change. When the opening direction is changed (step S237), the degree of superheat SHe decreases, and when the closing direction is changed (step S236), the degree of superheat SHe increases, and it can be confirmed whether or not the change is reasonable.

If no reasonable change is found in step S239 (no), the control device 110 advances the process to step S216 to execute an abnormal stop process (fig. 9) to abnormally stop the salt brine cooler.

If there is a reasonable change in step S239 (yes), the control device 110 advances the process to step S240, resets the timer T2, and then returns the process. Since the timer T2 is reset, the process of detecting an abnormality of the intermediate cooling expansion valve 8 is stopped.

As described above, in the refrigeration cycle apparatus according to embodiment 2, in the valve operation confirmation process, the valve opening degree is once changed in the direction opposite to the opening degree change direction of the periodic control, and then the opening degree is changed in the same direction. By controlling the valve opening in this manner, an effect of removing foreign matter caught in the driving portion of the electronic expansion valve can be expected.

(conclusion)

Hereinafter, the main features of the above-described embodiments will be summarized with reference to the drawings again.

The control device of the present embodiment is a control device of a refrigeration cycle device in which the main liquid expansion valve 5 is mounted. The control device 110 shown in fig. 1 and 7 includes: a memory 112 that stores a target value of a physical quantity desired to be controlled; and a CPU (processor) 111. The CPU111 is configured to execute processing including: i) an abnormality detection process of detecting an abnormality of the main liquid expansion valve 5 based on the physical quantity and the target value stored in the memory 112; ii) valve operation confirmation processing for, when abnormality of the main liquid expansion valve 5 is detected by the abnormality detection processing, transmitting a command for changing the opening degree to the main liquid expansion valve 5 and determining whether or not a change corresponding to the command is observed in the physical quantity; and iii) a stopping process of stopping the refrigeration cycle apparatus 100 or the salt chiller 200 in the valve operation checking process when no change is observed in the physical quantity.

As shown in fig. 2, the control device 110 executes regular control at regular time intervals (control cycles). In the periodic control, the current value of the control amount detected by the sensor is compared with a target value stored in the memory 112 in advance, and the opening degree of the electronic expansion valve is changed. Whereby the control amount is maintained in the vicinity of the target value.

The controller 110 performs an abnormality detection process for detecting an abnormality in the main liquid expansion valve 5 in parallel with the periodic control. In the abnormality detection processing, an abnormality determination amount such as the degree of superheat SHc is detected, and an abnormality is determined by the transition thereof. Before the abnormality detection process determines that the main liquid expansion valve 5 is abnormal and the refrigeration cycle apparatus is stopped, in the present embodiment, a valve operation confirmation process is performed that determines whether the main liquid expansion valve 5 is normal or abnormal by changing the opening degree of the main liquid expansion valve 5 to confirm a change in the physical quantity (normal determination quantity).

After the valve operation confirmation processing is performed, if the normal determination amount indicates a reasonable change in accordance with the change in the opening degree, the control device 110 determines that the electronic expansion valve is normal and ends the abnormality detection processing, and if not, determines that the electronic expansion valve is abnormal and continues the abnormality detection processing.

Here, the appropriate change means that when the opening degree of the expansion valve is changed in the opening direction, the degree of superheat, the supply temperature, and the discharge temperature decrease, the evaporation pressure (evaporation temperature) increases, and the like, due to an increase in the refrigerant flow rate. When the opening degree is changed in the closing direction, the change in the normal determination amount is reversed.

In addition, the control amount, the abnormality determination amount, and the normality determination amount are often the same physical amount and may be different.

The refrigeration cycle apparatus includes various sensors for detecting a control amount, an abnormality determination amount, and a normality determination amount.

Conventionally, when the "electronic expansion valve is normal but the operation state temporarily deviates from the normal range", there is a possibility that the electronic expansion valve may be abnormally stopped due to erroneous detection or excessive detection in the abnormality detection process. In the present embodiment, with such a configuration and control, the refrigeration cycle apparatus is not unnecessarily abnormally stopped unless the electronic expansion valve is determined to be normal by performing the valve operation checking process.

Further, the refrigeration cycle apparatus is desired to continue operating as much as possible without abnormally stopping. In the present embodiment, since the number of cases in which the system is not abnormally stopped increases, there is an effect that the supply of cold and hot water is not stopped and the system does not report an abnormality to the local system.

As shown in fig. 2, the CPU111 is preferably configured to: regular control is executed for instructing the amount of change in the opening degree of the main liquid expansion valve 5 or the oil cooling expansion valve 9 on the basis of the physical quantity and the target value at regular intervals. The CPU111 is configured to: in the valve operation confirmation process shown in step S110 in fig. 3 (or step S110 in fig. 6), a change amount in the same change direction, which is larger than the change amount calculated by the periodic control, is instructed to the main liquid expansion valve 5 (or the expansion valve 9 for oil cooling).

In the valve operation confirmation process, the "manipulated variable is Δ Pls × variable N" is output in step S111 in fig. 3 using the opening degree change amount Δ Pls of the regular control of the electronic expansion valve. Here, the opening degree variation Δ Pls and the variable N are both signed values. If the variable N is positive, a change in the opening degree in the same direction as Δ Pls is output, and if N is negative, a change in the opening degree in the opposite direction is output.

When the current opening degree of the electronic expansion valve is the maximum opening degree or the minimum opening degree, an opening degree exceeding it cannot be output, so in step S109, the variable N is set to a negative value (e.g., -1.0. ltoreq. n.ltoreq.0.5 or so), in the case where this is not the case, the variable N is set to a positive value (e.g., 1.5. ltoreq. n.ltoreq.2.0 or so) in step S110.

By performing the control in this manner, the valve operation confirmation process can be performed in consideration of the control range (not less than the minimum opening degree but not more than the maximum opening degree) of the electronic expansion valve.

When the variable N is positive, the opening degree can be changed to be larger than the variation Δ Pls in the periodic control by setting the variable N to be larger than 1. Thus, when the electronic expansion valve is normal, the change of the control amount, the abnormality determination amount, and the normality determination amount can be made faster (larger), the influence of the deviation of the temporary operation state can be suppressed, and whether the electronic expansion valve is normal or abnormal can be easily determined. Further, the abnormality detection processing can be immediately ended as long as the abnormality determination amount falls within the normal range.

On the other hand, when the variable N is negative, in a situation where foreign matter is stuck in the drive portion of the electronic expansion valve and does not operate normally, the valve is moved in a direction opposite to the drive direction in the periodic control, so that there is a possibility that the foreign matter is removed, and an effect of returning the operation of the electronic expansion valve to normal can be expected. When the variable N is negative, the control amount, the abnormality determination amount, and the normal determination amount change in a direction to increase the abnormality when the electronic expansion valve is operating normally, and therefore, when the variable N is negative, the size of the variable N is set to 1 or less.

As shown in fig. 2, CPU111 is preferably configured to: the regular control of the amount of change in the instructed opening degree of the main liquid expansion valve 5 is performed at regular intervals on the basis of the physical quantity and the target value. The CPU111 is configured to: in the valve operation confirmation processing shown in step S109 in fig. 3 or 5 or step S210 in fig. 8, a change amount in the opposite direction to the change amount calculated by the periodic control is instructed to the main liquid expansion valve 5.

In the valve operation confirmation process shown in fig. 3 or 5, in step S111 and in step S212 in fig. 8, the "operation amount ═ Δ Pls × variable N" is output using the opening degree variation Δ Pls of the regular control of the main liquid expansion valve 5. The opening degree variation Δ Pls and the variable N are signed values. At this time, the variable N is constantly set to negative, and the opening degree of the valve is changed in the direction opposite to the regular control.

In this valve operation confirmation process, the valve is moved in the direction opposite to the driving direction in the conventional periodic control regardless of the current opening degree, so that there is a possibility that foreign matter caught in the driving portion of the electronic expansion valve is removed, and an effect of returning the operation of the electronic expansion valve to normal can be expected.

Further, even if the abnormality determination amount falls within the abnormality range, the opening degree is changed in the direction opposite to the regular control, so that if the abnormality determination amount is changed further to the abnormal side, it can be determined that the electronic expansion valve is operating normally, and the refrigeration cycle apparatus can be prevented from being unnecessarily abnormally stopped.

As shown in fig. 2, CPU111 is preferably configured to: the regular control of the amount of change in the instructed opening degree of the main liquid expansion valve 5 is performed at regular intervals on the basis of the physical quantity and the target value. The CPU111 is configured to: in the valve operation checking process of fig. 8, the electronic expansion valve is instructed in advance in steps S205 to S207 based on the smaller one of the amount of change calculated by the periodic control and the value indicating the constant ratio of the current opening degree of the electronic expansion valve.

That is, as shown in step S205 of fig. 8, the operation amount δ Pls may be obtained by multiplying the current opening degree of the electronic expansion valve by the ratio (%) which is the set value, instead of "Δ Pls × variable N". This ratio is preset and stored in the memory 112 of the control device 110. The operation amount δ Pls here is only a magnitude and has no sign. Further, in step S206, the magnitudes of δ Pls and Δ Pls are compared, and the smaller opening degree change amount is used as the basis for calculation of the change amount of the expansion valve.

If the abnormality determination amount continues to fall within the abnormality range, the opening degree variation Δ Pls of the periodic control may become excessively large. In particular, when the opening degree is changed in the direction opposite to Δ Pls, the abnormality determination amount is further changed to the abnormality side, and therefore an excessively large opening degree change is not preferable. Thus, in the valve operation confirmation processing in fig. 8, by outputting a small amount of change in the opening degree, if the expansion valve is normal, it is possible to suppress sudden changes in the operating state due to a large change in the actual opening degree of the expansion valve, and to perform abnormal stop by the abnormality detection processing.

As shown in fig. 2, the CPU111 is preferably configured to: the amount of change in the opening degree of the intermediate cooling expansion valve 8 is periodically controlled at regular intervals based on the physical quantity and the target value. The CPU111 is configured to: in the valve operation checking process in step S236 in fig. 10, after a change amount in the direction opposite to the change amount Δ Pls calculated by the periodic control is temporarily instructed to the intermediate cooling expansion valve 8, a change amount in the same direction as the change amount calculated by the periodic control is instructed to the intermediate cooling expansion valve 8.

By changing the opening degree in the same direction after temporarily changing the opening degree in the opposite direction with respect to the changing direction of Δ PLs that is periodically controlled, an effect can be expected that foreign matter that has stuck in the drive portion of the electronic expansion valve is removed, and the operation of the electronic expansion valve returns to normal.

As shown in step S104 of fig. 3 or step S143 of fig. 6, it is preferable that the CPU111 counts an elapsed time from the detection of the abnormality in the abnormality detection processing, executes the valve operation confirmation processing when the elapsed time reaches a predetermined first time (for example, 15 minutes), and initializes the elapsed time when a change corresponding to the command is observed for the physical quantity as a result of the valve operation confirmation processing. The CPU111 is configured to: when the elapsed time is not initialized and reaches a predetermined second time (for example, 20 minutes) longer than the first time, the stop processing is executed. The CPU111 counts a dead time from when the abnormality is detected by the timer T2 to when the stop processing is performed, as the elapsed time, and executes the valve operation confirmation processing until the dead time reaches a predetermined time.

In the case of a temporary deviation of the operating state, since there is a possibility that the operating state returns to the normal range after the abnormality detection process is started, it is preferable to perform the valve operation confirmation process at a time of the latter half of the dead time (10 to 15 minutes after the dead time is 20 minutes) as much as possible in the timer timing of the dead time after the abnormality detection process is started.

This timer is, for example, a timer T2 which counts 20 minutes when the degree of superheat ≧ 30K is determined as abnormal in 20 minutes in step S105 or the like of FIG. 3.

As described above, when the operation state is returned to the normal range in the first half of the dead time by performing the valve operation check process in the timer operation in the dead time, particularly in the second half of the dead time, the valve operation based on the valve operation check process does not interfere with the operation of the expansion valve for each control cycle of the periodic control.

It is preferable that the determination time in step S104 and the determination time in step S105 in fig. 3 coincide with each other. An example of this is shown in fig. 10. In this case, the CPU111 counts the elapsed time from the detection of the abnormality in the abnormality detection process, executes the valve operation confirmation process when the elapsed time reaches a predetermined second time (for example, 20 minutes), and initializes the elapsed time when a change corresponding to the command is observed for the physical quantity as a result of the valve operation confirmation process. As a result of the valve operation checking process of the CPU111, the stop process is performed when no change corresponding to the command is observed for the physical quantity. That is, the CPU111 is configured to: the elapsed time from the detection of the abnormality in the abnormality detection processing to the execution of the stop processing is counted by a timer T2 as a dead time, and the valve operation confirmation processing is executed when the dead time reaches a predetermined time.

Specifically, the valve operation checking process is performed at 20 minutes when the degree of superheat is equal to or greater than 30K for 20 minutes, which is determined to be abnormal. The valve operation based on the valve operation confirmation processing in this case least interferes with the operation of the expansion valve per control cycle of the periodic control.

As shown in step S105 of fig. 5, the CPU111 is preferably configured to: the timer T2 counts the dead time from the detection of the abnormality in the abnormality detection process to the execution of the stop process, and as shown in step S108 in fig. 5, the valve operation confirmation process is executed at a time before the dead time reaches a predetermined time and the opening degree of the main liquid expansion valve 5 reaches the upper limit opening degree or the lower limit opening degree.

That is, in step S105 of fig. 5, the valve operation confirmation process is executed at the time when the expansion valve opening degree becomes the maximum opening degree or the minimum opening degree (yes in S108) 20 minutes before the time when the superheat degree ≧ 30K continues for 20 minutes and it is determined that there is an abnormality (no in S105).

When the steady operation is performed within the use range of the refrigeration cycle apparatus, it is not always possible to continue the abnormality determination amount within the abnormality range even if the maximum opening degree or the minimum opening degree is reached, and therefore it is reasonable to perform the valve operation confirmation process at such a timing. If the maximum opening degree or the minimum opening degree is reached, there is a possibility that the temporary operation state may be deviated, and the necessity of performing the valve operation confirmation process at this stage is low.

If the valve operation confirmation process is performed at such a timing, the valve operation confirmation process can be performed in a situation where there is a possibility of "long-time operation state deviation" or "electronic expansion valve abnormality" other than the situation of "temporary operation state deviation".

As shown in step S204 of fig. 8, it is preferable that the CPU111 is configured to determine that the physical quantity (e.g., the degree of superheat SHc) is out of the first range (e.g., 3K to 35K) by the abnormality detection processing, and to stop the refrigeration cycle apparatus by the stop processing. As shown in step S201 of fig. 8, the CPU111 is configured to: the abnormality detection processing is executed in a case where the physical quantity is outside a second range (for example, 7K to 27K) narrower than the first range. The CPU111 is configured to: the valve operation confirmation processing is executed when the physical quantity is out of the second range and enters the first range (for example, 3K to 7K or 27K to 35K).

In fig. 8, when it is detected that the abnormality determination amount is within the abnormality range, that is, when it is determined that the abnormality is present, a second threshold value is set at a position (normal side) wider than the first threshold value for determining the abnormality range, and when the second threshold value is reached, the operation of the valve operation confirmation process is confirmed.

For example, when the degree of superheat is less than or equal to 3K, that is, when it is determined that the abnormality is present, 3K applied in step S204 is the first threshold value. Further, 7K, which is applied in step S201 and slightly shifted to the normal side from 3K, is the second threshold.

By controlling in this way, even when the dead time as in the timer T2 of fig. 3 is not provided for the abnormality detection of the electronic expansion valve (when the first threshold value is satisfied, i.e., the abnormal stop is detected), the valve operation confirmation process can be applied. By providing the second threshold value that is shifted to the normal side from the first threshold value, the valve operation confirmation process can be performed in a certain operating state with a slight margin before the operating state to be abnormally stopped is reached.

The refrigeration cycle apparatus 100 preferably includes a compressor 1, an air-cooled condenser 3, a first blower that blows air to the air-cooled condenser 3, an evaporator 6, and a second blower that blows air to the evaporator 6. As shown in step S107 in fig. 3 or 6 or step S131 in fig. 5, the control device 110 is configured to: the valve operation checking process is executed in a state where the operating capacity of at least one of the compressor 1, the first blower, and the second blower is fixed.

Similarly, the brine chiller preferably includes a fixed speed compressor 31, a water cooled condenser 32, and a brine cooler 34. As shown in step S208 in fig. 8 or 10, the controller 110 is configured to execute the valve operation checking process in a state where the operating capacity of the fixed speed compressor 31 is fixed.

For example, when the blowers of the compressor, the condenser, and the evaporator are driven by inverters, the operation check of the valve operation check process is performed with the operating frequencies thereof fixed to a fixed value. In addition, even when the capacity (capacity) of the compressor is variable by using the mechanical capacity control mechanism, the operation check of the valve operation check process is performed by fixing the capacity of the capacity control mechanism.

The control of the electronic expansion valve and the control of the compressor and the blower are independent functions, and are often operated independently. Therefore, there is a possibility that the operating frequency of the compressor or the blower is changed even when the valve operation confirmation process is performed, and in this case, since the operating state (refrigerant state) is changed, there is a possibility that the normality/abnormality of the expansion valve cannot be accurately determined by the valve operation confirmation process.

By fixing the frequency in the case of inverter driving or the mechanical capacity in the case of the mechanical capacity control method, the operating state of the refrigeration cycle apparatus can be kept constant, and the normality or abnormality of the expansion valve can be appropriately determined by the valve operation checking process.

The physical quantity to be controlled in the present embodiment is preferably at least one of the degree of superheat of the refrigerant, the discharge temperature of the compressor 1, the oil temperature, the evaporation temperature of the refrigerant, and the evaporation pressure of the refrigerant in the

refrigeration cycle apparatus

100 or 200.

In controlling the electronic expansion valve, the control amount is often set to the superheat degree, but in the case of an electronic expansion valve for oil cooling, the supply oil temperature or the discharge temperature can be used. Further, although the degree of superheat is often used in the main liquid expansion valve, the evaporation pressure (evaporation temperature), the temperature in the storage, or the difference in the temperature in the storage (difference between the temperature in the storage and the set temperature) may be used as the control amount.

Various electronic expansion valves mounted in a refrigeration cycle apparatus can prevent erroneous detection of an abnormality and unnecessary stop of the refrigeration cycle apparatus.

The presently disclosed embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is indicated by the claims, rather than the description of the above embodiments, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.

Description of the reference numerals

1 … compressor; 2 … oil separator; 3 … air-cooled condenser; 4 … intercooler; 5 … main liquid expansion valve; 6 … evaporator; 7 … oil cooler; 8 … expansion valve for intermediate cooling; 9 … expansion valve for oil cooling; 10 … expansion valve for cooling motor; 11. 15-19, 28, 36, 37 … temperature sensor; 12-14 … pressure sensors; 20 … a main flow refrigerant pipe; 21 … a refrigerant pipe for an intercooler; 22 … refrigerant piping for an oil cooler; 23 … refrigerant piping for a motor cooler; 24 … oil supply piping; 25 … refrigerated warehouse; 26 … warehouse temperature sensor; 27 … evaporative pressure sensor; 31 … constant speed compressor; a 32 … water cooled condenser; 33 … cooling water piping; 34 … brine cooler; 35 … saline tubing; 38 … water-cooled oil cooler; 100 … refrigeration cycle device; 101 … cooling the source unit; 102 … load cell; 110 … control devices; 112 … memory; 200 … salting and cooling machine.

Claims

1. A control device for a refrigeration cycle device, the control device being equipped with an electronic expansion valve, the control device comprising:

a memory that stores a target value of a physical quantity desired to be controlled; and

a control part for controlling the operation of the display device,

the control unit is configured to execute:

i) an abnormality detection process of detecting an abnormality of the electronic expansion valve based on the physical quantity and the target value stored in the memory;

ii) a valve operation confirmation process of, when abnormality of the electronic expansion valve is detected by the abnormality detection process, transmitting a command to change an opening degree to the electronic expansion valve and determining whether or not a change corresponding to the command is observed in the physical quantity; and

iii) a stop process of stopping the refrigeration cycle apparatus when no change is observed in the physical quantity in the valve operation confirmation process.

2. The control device of a refrigeration cycle device according to claim 1,

the control unit is configured to: performing regular control of an amount of change in the indicated opening degree of the electronic expansion valve at regular intervals based on the physical quantity and the target value,

the control unit is configured to: in the valve operation checking process, a change amount larger than the change amount calculated by the periodic control in the same change direction is indicated to the electronic expansion valve.

3. The control device of the refrigeration cycle device according to claim 1,

the control unit is configured to: in the valve operation checking process, the electronic expansion valve is instructed to change in amount in a direction opposite to the amount of change calculated by the periodic control.

4. The control device of a refrigeration cycle device according to claim 1,

the control unit is configured to: in the valve operation confirmation process, the electronic expansion valve is instructed based on a smaller one of the amount of change calculated by the periodic control and a value indicating a constant ratio of the current opening degree of the electronic expansion valve.

5. The control device of the refrigeration cycle device according to claim 1,

the control unit is configured to: in the valve operation checking process, after a change amount in a direction opposite to the change amount calculated by the periodic control is temporarily instructed to the electronic expansion valve, the change amount in the same direction as the change amount calculated by the periodic control is instructed to the electronic expansion valve.

6. The control device of a refrigeration cycle device according to claim 1,

the control unit measures an elapsed time from detection of an abnormality in the abnormality detection processing, executes the valve operation confirmation processing when the elapsed time reaches a predetermined first time, and initializes the elapsed time when a change corresponding to the command is observed in the physical quantity as a result of the valve operation confirmation processing,

the control unit is configured to: the stop processing is performed when the elapsed time has not been initialized and has reached a predetermined second time longer than the first time.

7. The control device of the refrigeration cycle device according to claim 1,

the control unit measures an elapsed time from detection of an abnormality in the abnormality detection processing, executes the valve operation confirmation processing when the elapsed time reaches a predetermined second time, and initializes the elapsed time when a change corresponding to the command is observed in the physical quantity as a result of the valve operation confirmation processing,

the control unit is configured to: when the result of the valve operation checking process is that no change corresponding to the command is observed in the physical quantity, the stopping process is performed.

8. The control device of a refrigeration cycle device according to claim 1,

the control unit is configured to: the valve operation confirmation process is executed at a time when a dead time from detection of the abnormality in the abnormality detection process to execution of the stop process is counted by a timer and the opening degree of the electronic expansion valve reaches an upper limit opening degree or a lower limit opening degree before the dead time reaches a predetermined time.

9. The control device of a refrigeration cycle device according to claim 1,

the control unit stops the refrigeration cycle apparatus when the physical quantity is outside a first range,

the control unit detects an abnormality in the abnormality detection processing when the physical quantity is outside a second range narrower than the first range,

the control unit is configured to: in a case where the physical quantity is outside the second range and enters the first range, the valve action confirmation process is executed.

10. The control device of the refrigeration cycle device according to claim 1,

the refrigeration cycle device is provided with a compressor,

the control device executes the valve operation checking process in a state where an operating capacity of the compressor is fixed.

11. The control device of a refrigeration cycle device according to claim 1,

the refrigeration cycle device is provided with: a condenser and a blower for blowing air to the condenser,

the control device executes the valve operation checking process in a state where an operation capacity of the blower is fixed.

12. The control device of a refrigeration cycle device according to claim 1,

the refrigeration cycle device is provided with: an evaporator, and a blower for blowing air to the evaporator,

13. The control device of a refrigeration cycle device according to any one of claims 1 to 12,

the physical quantity is at least one of a degree of superheat of a refrigerant of the refrigeration cycle device, a discharge temperature of a compressor, an oil temperature, an evaporation temperature of the refrigerant, and an evaporation pressure of the refrigerant.

14. A refrigeration cycle apparatus, characterized in that,

a control device according to any one of claims 1 to 13.