JP5585113B2 - Refrigerant flow control device - Google Patents

Description

  The present invention relates to a refrigerant flow control device, and more particularly to a refrigerant flow control device that controls the amount of refrigerant supplied to an evaporator by adjusting the opening of an electronic expansion valve.

  For example, in a showcase that displays and sells products in a cooled state, an evaporator and an electronic expansion valve are provided inside, and a compressor and a condenser are provided outside thereof, and these evaporator, compressor, The storage of the showcase is maintained at a desired temperature state by circulating the refrigerant in a refrigeration cycle constituted by sequentially connecting a condenser and an electronic expansion valve.

  Specifically, the refrigerant outlet temperature at the evaporator outlet, the refrigerant inlet temperature at the evaporator inlet, and the refrigerant intermediate temperature at a predetermined intermediate position from the evaporator inlet to the outlet. The opening degree of the electronic expansion valve is controlled so that the intermediate temperature is equal to or lower than the inlet temperature and the outlet temperature is increased by a preset value with respect to the intermediate temperature (see, for example, Patent Document 1).

  Such a showcase is known to be effective in that the cooling efficiency can be constantly improved without being affected by pressure loss.

JP 2008-008555 A

  By the way, in a showcase that has a plurality of storages and displays and sells products in different temperature states for each storage, an evaporator and an electronic expansion valve are required for each storage, and the electronic expansion corresponding to each storage The opening of the valve will be controlled.

  Therefore, when the set temperature of the storage is changed, the equipment (evaporator, electronic expansion valve, etc.) corresponding to the storage needs to be replaced or changed, and the procedure becomes complicated. It was.

  In view of the above circumstances, an object of the present invention is to provide a refrigerant flow rate control device that can be used for a plurality of storage boxes and can be easily changed in the set temperature for each storage box.

To achieve the above object, a refrigerant flow rate control device according to the present onset Ming, in the refrigerant flow control device designed to control the supply amount of the refrigerant for the evaporator by regulating the opening degree of the electronic expansion valve, the evaporator The second refrigerant is disposed in the ventilation path through which the refrigerant that has passed through the first refrigerant flow path unit disposed in the ventilation path through which the internal atmosphere of one container passes passes through the first refrigerant flow path unit. The first refrigerant channel unit and the second refrigerant channel unit are connected in series in such a manner that they pass through the channel unit, and are arranged from the inlet to the outlet of the evaporator. A plurality of refrigerant temperature sensors for detecting the temperature of the refrigerant passing through the part are arranged at arbitrary intervals, and both the one container and the other container are cooled to the same temperature. When an operation command is given, the evaporator The refrigerant temperature sensor closest to the outlet is set as the outlet side detector, and the refrigerant temperature sensor closest to the refrigerant temperature sensor is detected on the upstream side of the refrigerant temperature sensor set in the outlet side detector. When the operation command is given to cool the one container and cool the other container at a temperature level higher than that of the one container, the second refrigerant is set. Any one of the refrigerant temperature sensors in the flow path unit is set as the intermediate detection unit, and the refrigerant temperature sensor closest to the refrigerant temperature sensor on the downstream side of the refrigerant temperature sensor set in the intermediate detection unit is set as the outlet side detection unit. a detection unit setting means for setting the said detected temperature of the refrigerant in the intermediate detection unit, it becomes less temperature of the refrigerant supplied to the evaporator, in the intermediate detection unit Characterized in that a valve opening control means for controlling the opening of the electronic expansion valve in a manner that the temperature of the refrigerant at the outlet side detecting section with respect to the temperature of the medium is increased by a preset value.

  According to the present invention, the refrigerant passes through the refrigerant flow path unit disposed in the ventilation path through which the internal atmosphere of one container passes, and the refrigerant is disposed in the ventilation path through which the internal atmosphere of the other container passes. The refrigerant passage units are connected in series in a mode of passing through the provided refrigerant passage units, and the detection unit setting means, when an operation command is given, based on predetermined setting conditions An intermediate detector is set at a predetermined intermediate position from the inlet to the outlet of the evaporator, and the temperature of the refrigerant detected by the valve opening control means in the intermediate detector is equal to or lower than the temperature of the refrigerant supplied to the evaporator. Since the opening degree of the electronic expansion valve is controlled in such a manner as described above, it is possible to freely control the location that becomes the evaporation completion point of the refrigerant supplied to the evaporator. As a result, there is an effect that it is possible to deal with a plurality of storage boxes and easily change the set temperature for each storage box.

FIG. 1 is a conceptual diagram conceptually showing the configuration of a cooling device to which a refrigerant flow rate control device according to an embodiment of the present invention is applied. FIG. 2 is a block diagram showing a control system of the cooling device shown in FIG. FIG. 3 is a flowchart showing the contents of the expansion valve control process performed by the controller shown in FIGS. 1 and 2.

  Exemplary embodiments of a refrigerant flow control device according to the present invention will be explained below in detail with reference to the accompanying drawings.

  FIG. 1 is a conceptual diagram conceptually showing the configuration of a cooling device to which a refrigerant flow rate control device according to an embodiment of the present invention is applied. The cooling device illustrated here is applied to the open showcase 10 that displays and sells products stored in the storages 11a and 11b.

  The open showcase 10 includes an evaporator 12 inside, and an electronic expansion valve 13, a condenser 14 and a compressor 15 on the outside. The evaporator 12, the electronic expansion valve 13, the condenser 14 and the compressor 15 are connected to each other by a refrigerant pipe 16 to constitute a refrigeration cycle in which refrigerant is circulated and supplied.

  The evaporator 12 is disposed inside the open showcase 10 and includes a first refrigerant channel unit 12a and a second refrigerant channel unit 12b. The 1st refrigerant | coolant flow path unit 12a is arrange | positioned by the ventilation path (not shown) through which the internal air (internal atmosphere) of the 1st storage (one storage) 11a which comprises the open showcase 10 passes. The refrigerant flow path is formed in a meandering shape. The first refrigerant flow path unit 12 a is provided in a manner continuous with the inlet portion of the evaporator 12.

  The 2nd refrigerant | coolant flow path unit 12b comprises the open showcase 10, and the ventilation path through which the internal air of the 2nd storage (other storage) 11b which adjoins the 1st storage 11a via a heat insulation partition plate passes. (Not shown), and the refrigerant flow path is formed in a meandering shape. The second refrigerant flow path unit 12b is provided such that the refrigerant that has passed through the first refrigerant flow path unit 12a passes through the second refrigerant flow path unit 12b and continues to the outlet of the evaporator 12. Thus, the evaporator 12 is formed by connecting the first refrigerant channel unit 12a and the second refrigerant channel unit 12b in series.

  The electronic expansion valve 13 is for adiabatically expanding the liquid refrigerant discharged from the condenser 14 and supplying it to the evaporator 12. In the present embodiment, the opening degree is changed based on the degree of superheat defined as the difference between the temperature of the refrigerant discharged from the evaporator 12 and the temperature of the refrigerant supplied to the evaporator 12, and the flow rate of the refrigerant passing therethrough Applying something that can be adjusted. More specifically, the electronic expansion valve 13 expands the opening when the degree of superheat is large, and reduces the opening when the degree of superheat is small.

  The compressor 15 compresses the low-temperature and low-pressure gas refrigerant discharged from the evaporator 12 and supplies it to the condenser 14 as a high-temperature and high-pressure gas refrigerant. In the present embodiment, when a pressure value setting command is given, an inverter compressor that can change the suction pressure according to the pressure value setting command is applied.

  In such a cooling device, the high-temperature and high-pressure gas refrigerant discharged from the compressor 15 dissipates heat in the condenser 14 to become a high-temperature and high-pressure liquid refrigerant. This high-temperature and high-pressure liquid refrigerant is adiabatically expanded by the electronic expansion valve 13 to become a low-temperature and low-pressure gas-liquid two-phase refrigerant and supplied to the evaporator 12. The low-temperature and low-pressure gas-liquid two-phase refrigerant supplied to the evaporator 12 exchanges heat with the internal air of the storage boxes 11a and 11b supplied by the blower fans 17a and 17b, and absorbs heat to become a low-temperature and low-pressure gas refrigerant. Thus, the storage boxes 11a and 11b are cooled. The low-temperature and low-pressure gas refrigerant that has passed through the evaporator 12 is sucked into the compressor 15 and again becomes a high-temperature and high-pressure gas refrigerant and supplied to the condenser 14.

  A plurality of refrigerant temperature sensors 21 to 28 are provided in the refrigerant flow path from the inlet portion to the outlet portion of the evaporator 12. More specifically, the inlet refrigerant temperature sensor 21 is provided at the inlet of the evaporator 12, the first outlet refrigerant temperature sensor 23 is provided at the outlet of the first refrigerant channel unit 12a, and the outlet of the second refrigerant channel unit 12b. The part is provided with a second outlet refrigerant temperature sensor 28. A first intermediate refrigerant temperature sensor 22 is provided in a region upstream of the first outlet refrigerant temperature sensor 23 and in the vicinity of the first outlet refrigerant temperature sensor 23, and the second outlet part. A second intermediate refrigerant temperature sensor 27 is provided in a region upstream of the refrigerant temperature sensor 28 and in the vicinity of the second outlet refrigerant temperature sensor 28. Further, a plurality of intermediate refrigerant temperature sensors 24 to 26 are provided at appropriate intervals in the upstream region of the second intermediate refrigerant temperature sensor 27 in the second refrigerant channel unit 12b. These refrigerant temperature sensors 21 to 28 are detection means for detecting the temperature of the refrigerant passing through the portion where the refrigerant temperature sensors 21 to 28 are disposed.

  FIG. 2 is a block diagram showing a control system of the cooling device shown in FIG. As shown in FIG. 2, the cooling device includes an input unit 40 and a controller 30.

  The input unit 40 is a unit for inputting various information such as a remote controller and a keyboard. Information input by the input means 40 is given to the controller 30 as a command signal.

  The controller 30 operates according to a program and data stored in a storage means such as a built-in memory (not shown), and mainly includes a detection unit setting unit 31 and a valve opening degree control unit 32.

  The detection unit setting unit 31 sets any one of the refrigerant temperature sensors 22 to 27 as an intermediate detection unit in accordance with a command signal given from the input unit 40, and sets any one of the refrigerant temperature sensors 23 to 28 to the outlet side. This is set in the detection unit.

  More specifically, when the command signal given from the input means 40 is to cool both the first storage 11a and the second storage 11b to the same temperature (pattern 1), the second intermediate refrigerant The temperature sensor 27 is set as an intermediate detection unit, and the second outlet refrigerant temperature sensor 28 is set as an outlet side detection unit. Moreover, when the command signal given from the input means 40 cools the 1st storage 11a, but does not cool the 2nd storage 11b (pattern 2), the 1st intermediate part refrigerant | coolant temperature sensor 22 is set. While setting to an intermediate | middle detection part, the 1st exit part refrigerant | coolant temperature sensor 23 is set to an exit side detection part. Furthermore, when the command signal given from the input means 40 cools the first storage 11a and cools the second storage 11b at a higher temperature level than the first storage 11a (pattern 3). Any one of the intermediate refrigerant temperature sensors 24 to 26 and the second intermediate refrigerant temperature sensor 27 is set as the intermediate detector, and the intermediate refrigerant temperature sensors 25 and 26, the second intermediate refrigerant temperature sensor 27, and the second outlet part are set. Any one of the refrigerant temperature sensors 28 is set as the outlet side detection unit.

  The valve opening degree control unit 32 is based on detection results of the inlet refrigerant temperature sensor 21, the refrigerant temperature sensors 23 to 28 set in the outlet detection unit, and the refrigerant temperature sensors 22 and 24 to 27 set in the intermediate detection unit. The opening degree of the electronic expansion valve 13 is adjusted, and a first temperature difference measuring unit 321, a second temperature difference measuring unit 322, and a valve opening degree setting unit 323 are provided.

  The first temperature difference measuring unit 321 detects the temperature of the inlet refrigerant temperature sensor 21 from the refrigerant temperature detected by the refrigerant temperature sensors 22 and 24 to 27 (hereinafter, also referred to as “intermediate refrigerant temperature T3”) set in the intermediate detector. The first refrigerant temperature difference Δt1 is calculated by subtracting the detected refrigerant temperature (hereinafter also referred to as “inlet refrigerant temperature T1”), that is, the temperature of the refrigerant supplied to the evaporator 12.

  The second temperature difference measuring unit 322 is an intermediate portion from the refrigerant temperature detected by the refrigerant temperature sensors 23, 25, 26, 27, and 28 set in the outlet side detection unit (hereinafter also referred to as “exit portion refrigerant temperature T2”). The second refrigerant temperature difference Δt2 is calculated by subtracting the refrigerant temperature T3.

  The valve opening setting unit 323 sets the opening of the electronic expansion valve 13 based on the first refrigerant temperature difference Δt1 and the second refrigerant temperature difference Δt2.

  FIG. 3 is a flowchart showing the contents of the expansion valve control process performed by the controller 30 shown in FIGS. 1 and 2. Hereinafter, the operation of the cooling device will be described with reference to FIG.

  As a premise, it is necessary to set an intermediate detector and an outlet side detector. Here, it is assumed that a command signal of pattern 1 (a pattern for cooling both the first storage 11a and the second storage 11b to the same temperature) is given from the input means 40. Thereby, the detection part setting part 31 of the controller 30 sets the 2nd intermediate part refrigerant | coolant temperature sensor 27 to an intermediate | middle detection part, and sets the 2nd exit part refrigerant | coolant temperature sensor 28 to an exit side detection part.

  When the cooling device is in an operating state, the valve opening degree control unit 32 of the controller 30 includes an inlet refrigerant temperature sensor 21, a second intermediate refrigerant temperature sensor 27 (intermediate detection unit), and a second outlet refrigerant temperature sensor 28 ( Each refrigerant temperature is detected through the outlet side detection unit (step S101), and it is determined whether or not the first refrigerant temperature difference Δt1 calculated through the first temperature difference measurement unit 321 is equal to or less than zero (step S102).

  When 1st refrigerant | coolant temperature difference (DELTA) t1 is zero or less (step S102: Yes), the valve opening degree control part 32 transfers a procedure to step S103 as it is. On the other hand, when 1st refrigerant | coolant temperature difference (DELTA) t1 is not zero or less (step S102: No), the valve opening degree control part 32 implements the process which increases the opening degree of the electronic expansion valve 13 through the valve opening degree setting part 323 ( Step S104), and then the procedure proceeds to Step S103.

  As the degree of opening of the electronic expansion valve 13 increases, the degree of superheating of the refrigerant decreases, and as a result, the temperature distribution of the evaporator 12 changes so that the intermediate cooling temperature becomes equal to or lower than the inlet refrigerant temperature T1.

  Next, the valve opening degree control unit 32 determines whether or not the second refrigerant temperature difference Δt2 calculated through the second temperature difference measurement unit 322 is a predetermined positive set value K (step S103). When 2nd refrigerant | coolant temperature difference (DELTA) t2 is the setting value K (step S103: Yes), the valve opening degree control part 32 complete | finishes this process as it is, and returns a procedure.

  On the other hand, when the second refrigerant temperature difference Δt2 is not the set value K (step S103: No), the valve opening degree control unit 32 sets the electronic expansion valve 13 so that the second refrigerant temperature difference Δt2 becomes the set value K. Adjust the opening and then return the procedure. Specifically, when the second refrigerant temperature difference Δt2 exceeds the set value K (step S105: Yes), a process for increasing the opening of the electronic expansion valve 13 is performed (step S106), while the second When the refrigerant temperature difference Δt2 is less than the set value K (step S105: No), a process of reducing the opening of the electronic expansion valve 13 (step S107) is performed. As a result, the outlet refrigerant temperature T2 is maintained at a temperature obtained by adding the set value K to the intermediate refrigerant temperature T3 in a state where the intermediate refrigerant temperature T3 is equal to or lower than the inlet refrigerant temperature T1.

  In this way, by controlling the opening of the electronic expansion valve 13 so that the intermediate refrigerant temperature T3 is equal to or lower than the inlet refrigerant temperature T1, the evaporation completion point of the refrigerant supplied to the evaporator 12 is determined as an intermediate detection unit (first detector). 2 intermediate refrigerant temperature sensor 27) and the outlet side detection part (second outlet refrigerant temperature sensor 28), and the first container 11a and The internal air of the 2nd storage 11b can be cooled, and the goods accommodated in these 1st storage 11a and the 2nd storage 11b can be cooled so that it may become the same temperature.

  Further, since the outlet refrigerant temperature T2 is controlled to be a value obtained by adding the set value K to the intermediate refrigerant temperature T3, there is a risk of causing a so-called liquid back phenomenon in which the compressor 15 sucks the liquid phase refrigerant. There is no.

  Thereby, if the expansion valve control process by the controller 30 described above is repeatedly performed at a predetermined cycle time, that is, the second refrigerant temperature is kept in a state where the evaporation completion point is always located between the intermediate detection unit and the outlet side detection unit. If the opening degree of the electronic expansion valve 13 is adjusted so that the difference Δt2 becomes a preset set value K, the cooling efficiency is constantly improved while cooling the first storage container 11a and the second storage container 11b to the same temperature. Can be improved.

  Next, it is assumed that a command signal of pattern 2 (a pattern in which the first storage 11a is cooled and the second storage 11b is not cooled) is given from the input unit 40. Thereby, the detection part setting part 31 of the controller 30 sets the 1st intermediate part refrigerant | coolant temperature sensor 22 to an intermediate | middle detection part, and sets the 1st exit part refrigerant | coolant temperature sensor 23 to an exit side detection part.

  When the cooling device is in an operating state, the valve opening degree control unit 32 of the controller 30 performs the processing shown in FIG. That is, the respective refrigerant temperatures are detected through the inlet refrigerant temperature sensor 21, the first intermediate refrigerant temperature sensor 22 (intermediate detection unit), and the first outlet refrigerant temperature sensor 23 (exit side detection unit) (step S101). It is determined whether or not the first refrigerant temperature difference Δt1 calculated through the first temperature difference measuring unit 321 is equal to or less than zero (step S102).

  When 1st refrigerant | coolant temperature difference (DELTA) t1 is zero or less (step S102: Yes), the valve opening degree control part 32 transfers a procedure to step S103 as it is. On the other hand, when 1st refrigerant | coolant temperature difference (DELTA) t1 is not zero or less (step S102: No), the valve opening degree control part 32 implements the process which increases the opening degree of the electronic expansion valve 13 through the valve opening degree setting part 323 ( Step S104), and then the procedure proceeds to Step S103.

  As the degree of opening of the electronic expansion valve 13 increases, the degree of superheating of the refrigerant decreases, and as a result, the temperature distribution of the evaporator 12 changes so that the intermediate cooling temperature becomes equal to or lower than the inlet refrigerant temperature T1.

  Next, the valve opening degree control unit 32 determines whether or not the second refrigerant temperature difference Δt2 calculated through the second temperature difference measurement unit 322 is a predetermined positive set value K (step S103). When 2nd refrigerant | coolant temperature difference (DELTA) t2 is the setting value K (step S103: Yes), the valve opening degree control part 32 complete | finishes this process as it is, and returns a procedure.

  On the other hand, when the second refrigerant temperature difference Δt2 is not the set value K (step S103: No), the valve opening degree control unit 32 sets the electronic expansion valve 13 so that the second refrigerant temperature difference Δt2 becomes the set value K. Adjust the opening and then return the procedure. Specifically, when the second refrigerant temperature difference Δt2 exceeds the set value K (step S105: Yes), a process for increasing the opening of the electronic expansion valve 13 is performed (step S106), while the second When the refrigerant temperature difference Δt2 is less than the set value K (step S105: No), a process of reducing the opening of the electronic expansion valve 13 (step S107) is performed. As a result, the outlet refrigerant temperature T2 is maintained at a temperature obtained by adding the set value K to the intermediate refrigerant temperature T3 in a state where the intermediate refrigerant temperature T3 is equal to or lower than the inlet refrigerant temperature T1.

  In this way, by controlling the opening of the electronic expansion valve 13 so that the intermediate refrigerant temperature T3 is equal to or lower than the inlet refrigerant temperature T1, the evaporation completion point of the refrigerant supplied to the evaporator 12 is determined as an intermediate detection unit (first detector). 1 intermediate part refrigerant temperature sensor 22) and the outlet side detection part (first outlet part refrigerant temperature sensor 23), the superheat degree of the evaporator 12 can be made small while the first container 11a While cooling the internal air, the internal air of the second storage 11b can be prevented from being cooled, and the product stored in the first storage 11a is cooled while the product stored in the second storage 11b Can not be cooled.

  Further, since the outlet refrigerant temperature T2 is controlled to be a value obtained by adding the set value K to the intermediate refrigerant temperature T3, there is a risk of causing a so-called liquid back phenomenon in which the compressor 15 sucks the liquid phase refrigerant. There is no.

  Thereby, if the expansion valve control process by the controller 30 described above is repeatedly performed at a predetermined cycle time, that is, the second refrigerant temperature is kept in a state where the evaporation completion point is always located between the intermediate detection unit and the outlet side detection unit. If the opening degree of the electronic expansion valve 13 is adjusted so that the difference Δt2 becomes a preset set value K, the first storage 11a is cooled, and the second storage 11b is not cooled, and is constantly cooled. Efficiency can be improved.

  Next, the command signal of the pattern 3 (The pattern which cools the 1st storage 11a and cools the 2nd storage 11b at a temperature level higher than the 1st storage 11a) from the input means 40 was given. To do. Thereby, the detection unit setting unit 31 of the controller 30 sets any one of the intermediate refrigerant temperature sensors 24 to 26 as the intermediate detection unit, and further downstream of the intermediate refrigerant temperature sensors 24 to 26 set as the intermediate detection unit. A certain intermediate refrigerant temperature sensor 25, 26 or the second outlet refrigerant temperature sensor 28 is set as the outlet side detector.

  More specifically, this relates to the set temperature of the second storage 11b given by the input means 40, but when the intermediate refrigerant temperature sensor 24 is set to the intermediate detection unit, the intermediate refrigerant temperature sensor 25 is connected to the outlet. When the intermediate refrigerant temperature sensor 25 is set as the intermediate detection unit, the intermediate refrigerant temperature sensor 26 is set as the outlet detection unit, and the intermediate refrigerant temperature sensor 26 is set as the intermediate detection unit. In this case, the second outlet refrigerant temperature sensor 28 is set as the outlet-side detector.

  Then, by performing the expansion valve control process as shown in FIG. 3 as described above, the evaporation completion point of the refrigerant supplied to the evaporator 12 is positioned between the intermediate detection unit and the outlet side detection unit. Cooling the internal air of the second storage 11b at a temperature level higher than that of the first storage 11a while cooling the internal air of the first storage 11a while reducing the degree of superheat of the evaporator 12. Can do.

  Further, since the outlet refrigerant temperature T2 is controlled to be a value obtained by adding the set value K to the intermediate refrigerant temperature T3, there is a risk of causing a so-called liquid back phenomenon in which the compressor 15 sucks the liquid phase refrigerant. There is no.

  Thereby, if the expansion valve control process by the controller 30 described above is repeatedly performed at a predetermined cycle time, that is, the second refrigerant temperature is kept in a state where the evaporation completion point is always located between the intermediate detection unit and the outlet side detection unit. If the opening degree of the electronic expansion valve 13 is adjusted so that the difference Δt2 becomes a preset set value K, the first storage 11a is cooled and the second storage 11b is at a higher temperature than the first storage 11a. Cooling efficiency can be constantly improved while cooling at a level.

  As described above, according to the refrigerant flow control device according to the embodiment of the present invention, the evaporator 12 is formed by connecting the first refrigerant channel unit 12a and the second refrigerant channel unit 12b in series. When the controller 30 receives a command from the input unit 40, the controller 30 sets the intermediate detection unit at a predetermined intermediate position from the inlet to the outlet of the evaporator 12 based on a predetermined setting condition. Since the opening degree of the electronic expansion valve 13 is controlled in such a manner that the temperature of the refrigerant detected by the detection unit is equal to or lower than the temperature of the refrigerant supplied to the evaporator 12, the evaporation completion point of the refrigerant supplied to the evaporator 12 Can be freely controlled. As a result, it is possible to deal with a plurality of storage boxes 11a and 11b, and it is possible to easily change the set temperature for each of the storage boxes 11a and 11b.

  Further, according to the refrigerant flow control device according to the embodiment of the present invention, the controller 30 sets the outlet side detection unit at an arbitrary position from the intermediate detection unit to the outlet unit, and sets the temperature of the refrigerant in the intermediate detection unit. On the other hand, since the opening degree of the electronic expansion valve 13 is controlled in such a manner that the temperature of the refrigerant in the outlet side detection unit increases by a preset value, there is no possibility of causing a so-called liquid back phenomenon.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to this, and various modifications can be made. That is, in the embodiment described above, the refrigerant flow control device is applied to the open showcase (cooling device) 10, but in the present invention, it may be applied to a vending machine. Absent. Moreover, it cannot be overemphasized that the location of the refrigerant | coolant temperature sensors 21-28 can be set freely and is not limited to what is shown in FIG.

  As mentioned above, the refrigerant | coolant flow control apparatus which concerns on this invention is useful for cooling of the storage of an open showcase, for example.

DESCRIPTION OF SYMBOLS 10 Open showcase 11a 1st storage 11b 2nd storage 12 Evaporator 12a 1st refrigerant | coolant flow path unit 12b 2nd refrigerant | coolant flow path unit 13 Electronic expansion valve 14 Condenser 15 Compressor 21-28 Refrigerant temperature sensor 30 Controller 31 Detection unit setting unit 32 Valve opening degree control unit 321 First temperature difference measuring unit 322 Second temperature difference measuring unit 323 Valve opening degree setting unit 40 Input means

Claims (1)

In the refrigerant flow control device that controls the amount of refrigerant supplied to the evaporator by adjusting the opening of the electronic expansion valve,
In the evaporator, the refrigerant that has passed through the first refrigerant flow path unit disposed in the ventilation path through which the internal atmosphere of one container passes is disposed in the ventilation path through which the internal atmosphere of the other container passes . in a manner passing through the second refrigerant flow path unit, a first refrigerant flow path unit and the second refrigerant flow path unit be comprised connected in series, the outlet from the inlet portion of the evaporator itself distribution A plurality of refrigerant temperature sensors that detect the temperature of the refrigerant that passes through the installed site are arranged at arbitrary intervals,
When an operation command for cooling both the one container and the other container to the same temperature is given, the refrigerant temperature sensor closest to the outlet of the evaporator is connected to the outlet side detector. And the refrigerant temperature sensor closest to the refrigerant temperature sensor on the upstream side of the refrigerant temperature sensor set in the outlet side detection unit is set as the intermediate detection unit, while the one container is cooled. In addition, when an operation command is given to cool the other container at a temperature level higher than that of the one container, any one of the refrigerant temperature sensors in the second refrigerant channel unit is set as an intermediate detection unit. Detecting unit setting means for setting the refrigerant temperature sensor closest to the refrigerant temperature sensor in the refrigerant passage downstream side of the refrigerant temperature sensor set in the intermediate detection unit to the outlet side detection unit ;
The temperature of the refrigerant detected in the intermediate detection unit is equal to or lower than the temperature of the refrigerant supplied to the evaporator, and the temperature of the refrigerant in the outlet side detection unit is preset with respect to the temperature of the refrigerant in the intermediate detection unit. And a valve opening degree control means for controlling the opening degree of the electronic expansion valve in such a manner that it is increased only by the determined value .

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