JP6896165B2 - Refrigeration cycle equipment - Google Patents

Description

The present invention relates to a refrigeration cycle device including an expansion valve control unit that adjusts the opening degree of the expansion valve.

Conventionally, in an electronic expansion valve, a technique has been disclosed in which a controllable opening range includes a range in which a plurality of types of refrigerants are used (see, for example, Patent Document 1). In the technique of Patent Document 1, the type of refrigerant is automatically determined at the time of trial run based on the degree of discharge superheat and the degree of suction superheat.

Japanese Unexamined Patent Publication No. 2017-141998

However, the refrigerating capacity of the evaporator to which the expansion valve is applied is changed even with one type of refrigerant. In the conventional technique, when an abnormality occurs in the detection of the temperature sensor at the outlet of the evaporator, there is a possibility that the expansion valve opening degree outside the proper use range of the capacity of the evaporator is output. If an expansion valve opening that exceeds the capacity of the evaporator is output, liquid back operation may occur and the compressor may fail. Further, if the expansion valve opening degree lower than the capacity of the evaporator is output, the inlet temperature of the compressor rises and overheating operation occurs, which may lead to the compressor failure.

The present invention is for solving the above problems, and is an appropriate range of use from the upper limit to the lower limit of the expansion valve opening degree according to the type of the refrigerant used and the refrigerating capacity of the evaporator to which the expansion valve is applied. It is an object of the present invention to provide a refrigerating cycle apparatus capable of determining a compressor without causing a liquid back operation or an overheating operation and suppressing a compressor failure.

The refrigerating cycle apparatus according to the present invention includes a refrigerant circuit in which refrigerant pipes are connected in the order of a compressor, a condenser, an expansion valve, and an evaporator, and an expansion valve control unit for adjusting the opening degree of the expansion valve. the expansion valve control unit is a state that stores a first table which defines the relationship between the expansion valve and refrigerating capacity and a plurality of types of refrigerant, and defining the relationship between the evaporator capacity range and applications and horsepower In a state where the second table is stored, the evaporator capacity range is determined according to the input application and horsepower based on the second table, and the determined evaporator capacity range and the input refrigerant are determined. It is configured to collate with the first table and determine an appropriate range of use from the upper limit to the lower limit of the expansion valve opening degree according to the refrigerant to be used.

According to the refrigeration cycle apparatus according to the present invention, the expansion valve control unit stores a refrigerating capacity that quantifies the evaporator capacity range and a first table that defines the relationship between a plurality of types of refrigerants and the expansion valve opening degree. Based on the first table, the appropriate range of use from the upper limit to the lower limit of the expansion valve opening according to the refrigerant to be used is determined. Therefore, the appropriate range of use from the upper limit to the lower limit of the expansion valve opening can be determined according to the type of refrigerant used and the refrigerating capacity of the evaporator to which the expansion valve is applied, and liquid back operation or overheating operation is prevented. , Compressor failure can be suppressed.

It is a refrigerant circuit diagram which shows the refrigerating cycle apparatus which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structure of the expansion valve control part which concerns on Embodiment 1 of this invention. It is a functional block diagram which shows the function of the expansion valve control part which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the 1st table which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the 2nd table which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the state which determines the appropriate use range using the 1st table which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the appropriate use range after determination which concerns on Embodiment 1 of this invention. It is a flowchart which shows the expansion valve opening degree determination control routine which concerns on Embodiment 1 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each figure, those having the same reference numerals are the same or equivalent thereof, and they are common in the entire text of the specification. Further, in the cross-sectional view, hatching is omitted as appropriate in view of visibility. Furthermore, the forms of the components shown in the full text of the specification are merely examples and are not limited to these descriptions.

Embodiment 1.
<Refrigeration cycle device 100>
FIG. 1 is a refrigerant circuit diagram showing a refrigeration cycle device 100 according to a first embodiment of the present invention.

As shown in FIG. 1, the refrigeration cycle device 100 includes a compressor 1, a condenser 2, an expansion valve 3, and an evaporator 4. The compressor 1, the condenser 2, the expansion valve 3, and the evaporator 4 are connected in order by a refrigerant pipe to form a refrigerant circuit. Then, the refrigerant flowing out of the evaporator 4 is sucked into the compressor 1 and becomes high temperature and high pressure. The high temperature and high pressure refrigerant is condensed in the condenser 2 to become a liquid. The liquid refrigerant is decompressed and expanded by the expansion valve 3 to become a low-temperature low-pressure gas-liquid two-phase, and the gas-liquid two-phase refrigerant heat exchanges in the evaporator 4.

Examples of the refrigerating cycle device 100 include an air conditioner, a refrigerating device, a water heater, and the like.

The expansion valve 3 is a flow rate control valve, which decompresses and expands the refrigerant. The expansion valve 3 is configured as an electronic expansion valve. Therefore, the expansion valve 3 integrally includes an expansion valve control unit 5. The expansion valve 3 can communicate with the expansion valve control unit 5 via a wired or wireless communication line 6, and the opening degree can be adjusted based on the instruction of the expansion valve control unit 5.

<Functional configuration of expansion valve control unit 5>
FIG. 2 is a block diagram showing a configuration of an expansion valve control unit according to a first embodiment of the present invention. FIG. 3 is a functional block diagram showing the function of the expansion valve control unit 5 according to the first embodiment of the present invention. Here, among the functions of the expansion valve control unit 5, a function of determining the opening degree of the expansion valve 3, which is a feature of the first embodiment described later, within an appropriate use range will be described. As another function, the expansion valve control unit 5 can appropriately control the opening degree of the expansion valve 3 during operation of the refrigeration cycle device 100 and the like according to the operating conditions.

As shown in FIG. 2, the expansion valve control unit 5 is a processing circuit including a microcomputer including a memory such as a CPU, ROM and RAM, and an input / output device such as an I / O port.

As shown in FIG. 3, the expansion valve control unit 5 is configured as a processing circuit including an input unit 5a, a storage unit 5b, a range determination unit 5c, an opening degree determination unit 5d, and a control unit 5e. There is.

In the input unit 5a, the purpose, horsepower, and refrigerant of the refrigeration cycle device 100 used as usage information are input by the setter. The input unit 5a may input the usage information by its own switches, or may be input by a communication line or a connected storage medium.

The storage unit 5b is composed of a storage medium such as a ROM, a RAM, and a flash memory. The storage unit 5b stores the first table and the second table.

FIG. 4 is an explanatory diagram showing a first table according to the first embodiment of the present invention. As shown in FIG. 4, the first table defines the refrigerating capacity in which the evaporator capacity range is quantified and the relationship between a plurality of types of refrigerants and the expansion valve opening degree. That is, by collating the refrigerant to be used and the refrigerating capacity in the first table, it is possible to determine an appropriate range of use from the upper limit to the lower limit of the expansion valve opening degree according to the refrigerant to be used.

FIG. 5 is an explanatory diagram showing a second table according to the first embodiment of the present invention. The second table defines the application and the relationship between horsepower and evaporator capacity range. That is, by collating the usage and horsepower input by the setter in the second table, the evaporator capacity range according to the usage and horsepower to be used can be determined.

The range determination unit 5c performs a process of collating the application and horsepower input to the input unit 5a with the second table and determining the evaporator capacity range according to the input application and horsepower. As shown in FIG. 5, it is assumed that the input use is for refrigeration, which is for refrigeration and for freezing, and has a horsepower of 10. In this case, the range determination unit 5c substitutes these information into each value in the second table. The second table has a column for use on the vertical axis and a column for horsepower on the horizontal axis. Therefore, when the application and horsepower are input, the upper limit of the evaporator capacity is determined to be 25.0 and the lower limit of the capacity is determined to be 10.0, as in the shaded intersection.

The opening degree determining unit 5d collates the evaporator capacity range determined by the range determining unit 5c with the refrigerant input to the input unit 5a against the first table, and collates the expansion valve opening degree from the upper limit to the lower limit according to the refrigerant used. Perform the process to determine the appropriate range of use up to.

FIG. 6 is an explanatory diagram showing a state in which an appropriate range of use is determined using the first table according to the first embodiment of the present invention. As shown in FIG. 6, the opening degree determining unit 5d includes 25.0 of the upper limit of the capacity and 10.0 of the lower limit of the capacity, which are the evaporator capacity ranges determined by the range determining unit 5c, and R410A as the refrigerant to be used. Is entered in the first table. The first table has a scale of refrigerating capacity in which the evaporator capacity range is quantified on the vertical axis, and a scale of expansion valve opening on the horizontal axis. Then, the characteristic lines corresponding to the plurality of types of refrigerants are placed on the first table. Therefore, when the upper limit of capacity of 25.0, the lower limit of capacity of 10.0, and R410A as the refrigerant to be used are input, the evaporator capacity range with respect to the characteristic line of R410A is set like a shaded portion. It is decided. When the upper limit value and the lower limit value of the evaporator capacity range are drawn straight downward to match the scale of the expansion valve opening, the appropriate use range from the upper limit to the lower limit of the expansion valve opening is determined. The appropriate range of use of R410A is determined by a MAX opening of 800 and a MIN opening of 450 as shown in FIG. 7, which will be described later.

The control unit 5e performs a process of controlling the opening degree of the expansion valve 3 within an appropriate use range of the expansion valve opening degree determined by the opening degree determination unit 5d. That is, the control unit 5e controls the opening degree of the expansion valve 3 within the appropriate use range from the upper limit to the lower limit of the expansion valve opening degree determined by the opening degree determination unit 5d, and sets the opening degree outside the proper use range. Control so that it does not become.

FIG. 7 is an explanatory diagram showing an appropriate range of use after determination by the opening degree determining unit 5d according to the first embodiment of the present invention. As shown in FIG. 7, the opening degree determination unit 5d determines the appropriate use range of R410A to be 800 MAX opening degree and 450 MIN opening degree. These values in FIG. 7 are stored in the storage unit 5b. As a result, the control unit 5e controls the opening degree of the expansion valve 3 between the MAX opening degree of 800 and the MIN opening degree of 450. The details of controlling the expansion valve opening degree of the control unit 5e according to the operating state of the refrigeration cycle device 100 will be omitted. During the normal operation of the refrigeration cycle apparatus 100, the control unit 5e uses the table of FIG. 7 in which the routine described later is executed and stored in the storage unit 5b in advance, and the MAX opening degree of 800 and the MIN opening degree of 450 are set. The opening degree of the expansion valve 3 is controlled between them.

<Expansion valve opening determination control routine>
FIG. 8 is a flowchart showing an expansion valve opening degree determination control routine by the expansion valve control unit 5 according to the first embodiment of the present invention. The routine shown in FIG. 8 is carried out at the time of initial operation or reset of the refrigeration cycle device 100.

This routine starts at the time of initial operation or reset of the refrigeration cycle device 100.

In step S101, the input unit 5a of the expansion valve control unit 5 determines the use, horsepower, and whether or not the refrigerant has been input. When it is determined in step S101 that the application, horsepower, and refrigerant have been input, the process proceeds to step S102. If the application, horsepower, and refrigerant are not input in step S101, this routine is temporarily terminated.

In step S102, the range determination unit 5c of the expansion valve control unit 5 determines the evaporator capacity range using the second table stored in the storage unit 5b based on the application and horsepower. The details are as described in the range determination unit 5c described above. When the process of step S102 is completed, the process proceeds to step S103.

In step S103, the opening degree determining unit 5d of the expansion valve control unit 5 uses the first table stored in the storage unit 5b from the refrigerant to be used and the evaporator capacity range as the refrigerating capacity determined in step S102. Determine the appropriate range of use from the upper limit to the lower limit of the expansion valve opening according to the refrigerant used. The details are as described in the opening degree determining unit 5d described above. When the process of step S103 is completed, the process proceeds to step S104.

In step S104, the control unit 5e of the expansion valve control unit 5 controls the opening degree of the expansion valve 3 within an appropriate range of use from the upper limit to the lower limit of the expansion valve opening degree according to the refrigerant used. The details are as described in the control unit 5e described above. When the process of step S104 is completed, this routine ends once.

In the normal operation other than the initial operation or the reset of the refrigeration cycle device 100, the control unit 5e of the expansion valve control unit 5 previously executes this routine and stores it in advance, as in step S104. The opening degree of the expansion valve 3 is controlled within an appropriate range of use from the upper limit to the lower limit of the expansion valve opening degree according to the refrigerant to be used stored in the part 5b.

<Application example>
The refrigeration cycle device 100 includes a pressure sensor and a temperature sensor between the evaporator outlet and the compressor 1. The pressure sensor may be replaced by an evaporator inlet temperature sensor. Then, when a state in which the value of the refrigerant superheat degree at the evaporator outlet is continuously out of the predetermined range occurs, the control unit 5e of the expansion valve control unit 5 may correct the expansion valve opening range. good. Specifically, the control unit 5e of the expansion valve control unit 5 adjusts the value of the MIN opening degree by 1.05 times when the value of the refrigerant superheat degree at the evaporator outlet is larger than a predetermined range. .. Further, the control unit 5e of the expansion valve control unit 5 adjusts to multiply the value of the MAX opening degree by 0.95 when the value of the refrigerant superheat degree at the evaporator outlet is smaller than the predetermined range. The control unit 5e of the expansion valve control unit 5 repeats these adjustments until the value of the refrigerant superheat degree at the evaporator outlet falls within a predetermined range.

<Effect of Embodiment 1>
According to the first embodiment, the refrigerating cycle device 100 includes a refrigerant circuit in which the refrigerant pipes are connected in the order of the compressor 1, the condenser 2, the expansion valve 3, and the evaporator 4. The refrigeration cycle device 100 includes an expansion valve control unit 5 that adjusts the opening degree of the expansion valve 3. The expansion valve control unit 5 stores a first table that defines the refrigerating capacity in which the evaporator capacity range is quantified and the relationship between a plurality of types of refrigerants and the expansion valve opening degree, and uses the refrigerant based on the first table. It is configured to determine the appropriate range of use from the upper limit to the lower limit of the expansion valve opening according to the situation.

According to this configuration, the first table defines the refrigerating capacity in which the evaporator capacity range is quantified and the relationship between the plurality of types of refrigerants and the expansion valve opening degree. By collating the refrigerant to be used and the refrigerating capacity in the first table, it is possible to determine an appropriate range of use from the upper limit to the lower limit of the expansion valve opening according to the refrigerant to be used. As a result, even if an abnormality occurs in the detection of the temperature sensor at the outlet of the evaporator, the expansion valve opening degree outside the proper use range of the capacity of the evaporator 4 is not output. In this way, the appropriate range of use from the upper limit to the lower limit of the expansion valve opening can be determined according to the type of the refrigerant used and the refrigerating capacity of the evaporator 4 to which the expansion valve 3 is applied, and the liquid back operation or overheating can be determined. The operation is prevented, and the failure of the compressor 1 can be suppressed.

According to the first embodiment, the expansion valve control unit 5 stores a second table that defines the use and the relationship between the horsepower and the evaporator capacity range, and based on the second table, according to the input use and horsepower. It is configured to determine the evaporator capacity range.

According to this configuration, the second table defines the application and the relationship between horsepower and evaporator capacity range. By collating the usage and horsepower input by the setter in the second table, the evaporator capacity range according to the usage and horsepower to be used can be determined. Therefore, the setter can determine the evaporator capacity range from the intended use and horsepower without knowing the refrigerating capacity that quantifies the evaporator capacity range.

According to the first embodiment, the expansion valve control unit 5 is configured to control the opening degree of the expansion valve 3 within an appropriate use range of the determined expansion valve opening degree.

According to this configuration, the opening degree of the expansion valve 3 is controlled within an appropriate range of use from the upper limit to the lower limit of the expansion valve opening degree determined by the expansion valve control unit 5. Therefore, the expansion valve opening degree is not controlled outside the proper use range from the upper limit to the lower limit. As a result, even if an abnormality occurs in the detection of the temperature sensor at the outlet of the evaporator, the expansion valve opening degree outside the proper use range of the capacity of the evaporator 4 is not output. Therefore, the liquid back operation or the overheating operation can be prevented, and the failure of the compressor 1 can be suppressed.

According to the first embodiment, the expansion valve control unit 5 puts the input unit 5a for inputting the usage information, the storage unit 5b storing the first table, and the usage information input to the input unit 5a into the first table. It has an opening degree determining unit 5d that collates and determines an appropriate use range of the expansion valve opening degree, and a control unit 5e that controls the opening degree of the expansion valve 3 within the determined appropriate use range of the expansion valve opening degree. Includes processing circuit.

According to this configuration, the first table defines the refrigerating capacity in which the evaporator capacity range is quantified and the relationship between the plurality of types of refrigerants and the expansion valve opening degree. By collating the refrigerant used as usage information with the refrigerating capacity in the first table, it is possible to determine an appropriate usage range from the upper limit to the lower limit of the expansion valve opening degree according to the refrigerant used. Then, the opening degree of the expansion valve 3 is controlled within an appropriate use range from the upper limit to the lower limit of the expansion valve opening degree determined by the expansion valve control unit 5. Therefore, the expansion valve opening degree is not controlled outside the proper use range from the upper limit to the lower limit. As a result, even if an abnormality occurs in the detection of the temperature sensor at the outlet of the evaporator, the expansion valve opening degree outside the proper use range of the capacity of the evaporator 4 is not output. In this way, the appropriate range of use from the upper limit to the lower limit of the expansion valve opening can be determined according to the type of the refrigerant used and the refrigerating capacity of the evaporator 4 to which the expansion valve 3 is applied, and the liquid back operation or overheating can be determined. The operation is prevented, and the failure of the compressor 1 can be suppressed.

According to the first embodiment, the storage unit 5b stores the second table. The expansion valve control unit 5 has a range determination unit 5c in the processing circuit that collates the usage information input to the input unit 5a with the second table to determine the evaporator capacity range.

According to this configuration, the second table defines the application and the relationship between horsepower and evaporator capacity range. By collating the usage and horsepower input by the setter as usage information in the second table, the evaporator capacity range according to the usage and horsepower to be used can be determined. Therefore, the setter can determine the evaporator capacity range from the intended use and horsepower without knowing the refrigerating capacity that quantifies the evaporator capacity range.

According to the first embodiment, the usage information is the application, horsepower and refrigerant used in the refrigeration cycle apparatus 100.

According to this configuration, the appropriate usage range from the upper limit to the lower limit of the expansion valve opening according to the usage, horsepower and refrigerant is determined only by inputting the usage, horsepower and refrigerant used by the setter as usage information. it can. As a result, even if an abnormality occurs in the detection of the temperature sensor at the outlet of the evaporator, the expansion valve opening degree outside the proper use range of the capacity of the evaporator 4 is not output. Therefore, the liquid back operation or the overheating operation can be prevented, and the failure of the compressor 1 can be suppressed.

According to the first embodiment, the expansion valve control unit 5 includes an input unit 5a for inputting the intended use, horsepower and refrigerant, a refrigerating capacity in which the evaporator capacity range is quantified, and a plurality of types of refrigerants and an expansion valve opening degree. The first table that defines the relationship with, the storage unit 5b that stores the second table that defines the relationship between the application and horsepower and the evaporator capacity range, and the second table that stores the application and horsepower input to the input unit 5a. The range determining unit 5c that determines the evaporator capacity range according to the application and horsepower input in accordance with the above, the evaporator capacity range determined by the range determining unit 5c, and the refrigerant input to the input unit 5a are first. The opening degree determining unit 5d that determines the appropriate use range from the upper limit to the lower limit of the expansion valve opening according to the refrigerant used by collating with the table, and the expansion valve 3 within the determined appropriate use range of the expansion valve opening. Includes a processing circuit including a control unit 5e for controlling the opening degree of the above.

According to this configuration, the second table defines the application and the relationship between horsepower and evaporator capacity range. By collating the usage and horsepower input by the setter in the second table, the evaporator capacity range according to the usage and horsepower to be used can be determined. In addition, the first table defines the refrigerating capacity in which the evaporator capacity range is quantified and the relationship between a plurality of types of refrigerants and the expansion valve opening degree. By collating the refrigerant to be used and the refrigerating capacity in the first table, it is possible to determine an appropriate range of use from the upper limit to the lower limit of the expansion valve opening according to the refrigerant to be used. Then, the opening degree of the expansion valve 3 is controlled within an appropriate range of use from the upper limit to the lower limit of the expansion valve opening degree determined by the expansion valve control unit 5. Therefore, the expansion valve opening degree is not controlled outside the proper use range from the upper limit to the lower limit. As a result, even if an abnormality occurs in the detection of the temperature sensor at the outlet of the evaporator, the expansion valve opening degree outside the proper use range of the capacity of the evaporator 4 is not output. In this way, the appropriate range of use from the upper limit to the lower limit of the expansion valve opening can be determined according to the type of the refrigerant used and the refrigerating capacity of the evaporator 4 to which the expansion valve 3 is applied, and the liquid back operation or overheating can be determined. The operation is prevented, and the failure of the compressor 1 can be suppressed.

According to the first embodiment, the expansion valve 3 is an electronic expansion valve in which the expansion valve control unit 5 is integrated.

According to this configuration, since the expansion valve 3 is an electronic expansion valve in which the expansion valve control unit 5 is integrated, there are no extra parts in the refrigeration cycle device 100, and the number of parts does not increase. The expansion valve 3 and the expansion valve control unit 5 do not necessarily have to be integrated.

1 Compressor, 2 Condenser, 3 Expansion valve, 4 Evaporator, 5 Expansion valve control unit, 5a input unit, 5b storage unit, 5c range determination unit, 5d opening determination unit, 5e control unit, 6 communication lines, 100 Refrigeration cycle equipment.

Claims (7)

A refrigerant circuit in which the refrigerant pipes are connected in the order of compressor, condenser, expansion valve and evaporator,
An expansion valve control unit that adjusts the opening degree of the expansion valve,
With
The expansion valve control unit is a state that stores a first table which defines the relationship between the expansion valve and refrigerating capacity and a plurality of types of refrigerant, defines the relationship between the evaporator capacity range and applications and horsepower In the state where the second table is stored, the evaporator capacity range is determined according to the input application and horsepower based on the second table, and the determined evaporator capacity range and the input refrigerant are used. the configured to determine the proper operating range from the upper limit to the lower limit of the expansion valve opening corresponding to the refrigerant used by collating the first table the refrigeration cycle apparatus. The refrigeration cycle apparatus according to claim 1, wherein the expansion valve control unit is configured to control the opening degree of the expansion valve within the proper use range of the determined expansion valve opening degree. The expansion valve control unit
Input section for entering usage information and
A storage unit that stores the first table and
An opening degree determining unit that collates the usage information input to the input unit with the first table to determine the appropriate usage range of the expansion valve opening degree.
A control unit that controls the opening degree of the expansion valve within the proper use range of the determined expansion valve opening degree,
The refrigeration cycle apparatus according to claim 1 or 2 , further comprising a processing circuit having the above. The storage unit stores the second table and stores it.
The expansion valve control unit, to the processing circuit, according to claim 3 having a range determination unit configured to determine the evaporator capacity range the use information input to the input unit by collating the second table Refrigeration cycle equipment. The refrigeration cycle device according to claim 3 or 4 , wherein the usage information is an application, horsepower, and a refrigerant used for the refrigeration cycle device. The expansion valve control unit
Input section for inputting usage, horsepower and refrigerant,
A first table that defines the refrigerating capacity that quantifies the evaporator capacity range and the relationship between a plurality of types of refrigerants and the expansion valve opening, and a second table that defines the relationship between the application and horsepower and the evaporator capacity range. And the memory part that memorized
A range determination unit that collates the application and horsepower input to the input unit with the second table and determines the evaporator capacity range according to the input application and horsepower.
The proper use of the expansion valve opening degree from the upper limit to the lower limit according to the refrigerant used by collating the evaporator capacity range determined by the range determining unit with the refrigerant input to the input unit against the first table. The opening determination unit that determines the range and the opening determination unit
A control unit that controls the opening degree of the expansion valve within the proper use range of the determined expansion valve opening degree,
The refrigeration cycle apparatus according to claim 1, further comprising a processing circuit having the above. The refrigeration cycle apparatus according to any one of claims 1 to 6 , wherein the expansion valve is an electronic expansion valve in which the expansion valve control unit is integrated.

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