KR100774090B1 - Refrigerating device - Google Patents

Abstract

When the guard timer of the compressor 141 ends, the R2 signal from the outdoor unit controller 140 is turned on (operation I). In the control unit 120 of the refrigerating unit, when the R2 signal is turned on and it is determined that a request for a refrigeration thermo-on has been generated based on the temperature in the reservoir detected by the temperature sensor 124 (operation II), the refrigerating solenoid valve 121 opens (Operation III). Normally, when the refrigerating solenoid valve 121 is opened, the rise of the suction refrigerant pressure is detected by the pressure sensor 146 to start the compressor 141. However, when the outside air temperature is low, the suction refrigerant pressure is lower than the predetermined value. Stay. Thus, the control unit 120 activates the booster compressor 131 (operation IV) to increase the suction refrigerant pressure of the compressor 141.

Description

Freezer {REFRIGERATING DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating device, and more particularly, to a technique for improving the compressor starting operation when the outside air temperature is low.

Conventionally, in a store such as a convenience store, a refrigerating device in which a refrigerating unit for refrigerating while displaying a product in a refrigerating showcase and a refrigerating unit for refrigerating while displaying a product in a refrigerating showcase is connected to one refrigerant circuit has been used.

Fig. 15 is a refrigerant circuit diagram for explaining the outline of the operation of the conventional refrigeration apparatus 5.

In the refrigerating device 5, the refrigerant compressed by the compressor 541 in the outdoor unit 54 installed outdoors condenses while radiating heat from the condenser 542. The condensed liquid refrigerant is branched into the refrigeration unit 51 and the refrigeration unit 52. The refrigerant introduced into the refrigerating unit 51 is reduced in pressure by the expansion valve 512 and evaporates while being absorbed from the air in the refrigerator by the refrigerating evaporator 513. In addition, the refrigerant introduced into the refrigerating unit 52 is reduced in pressure by the expansion valve 522 and evaporates while being absorbed from the air in the freezer by the freezer evaporator 523.

The refrigerant saturation pressure in the freezer evaporator 523 is kept lower than the refrigeration evaporator 513 by the booster compressor 531 in the booster unit 53. The evaporation temperature (about -5 ° C) of the freezing evaporator 523 is kept lower than the evaporation temperature (about 5 ° C) of the refrigeration evaporator 513.

When the cooling is continued and the temperature of the air in the storage unit in the refrigerating unit 51 or the refrigerating unit 52 reaches a preset target temperature, the solenoid valve 511 and the solenoid valve 521 are closed. . As a result, the supply of refrigerant to the evaporator 513 and the evaporator 523 is blocked (referred to as a refrigerated thermo-off state and a refrigerated thermo-off state, respectively).

On the other hand, in the control unit 540 (including a microprocessor, a ROM, a RAM, etc. and executing a predetermined program), the suction side refrigerant pressure of the compressor 541 is detected by the pressure sensor 546, and the value is a predetermined value. When the pressure is lower than 0.10 MPa (for example, 0.10 MPa), the compressor 541 is temporarily stopped (outdoor thermo-off state).

On the contrary, when the outdoor thermo-off state, in the refrigerating unit 51 or the freezing unit 52, a temperature difference of a predetermined size occurs between the air temperature in the reservoir and the target temperature, the solenoid valve 511, the solenoid valve ( 521 are opened, respectively, and supply of refrigerant to the evaporator 513 and the evaporator 523 is required (reserved thermo-on state and refrigerated thermo-on state, respectively). On the other hand, the control unit 540 detects that the suction refrigerant pressure has risen above a predetermined value (for example, 0.25 MPa) by the pressure sensor 546 and is controlled to start the compressor 541 (outdoor thermo-on state). do.

In this way, in the refrigerating device 5, the pressure sensor 546 can detect whether it is necessary to circulate the refrigerant to either of the evaporators 513 and 523 to continue the operation of the compressor 541. This allows the refrigeration unit 51 or the refrigerating unit 52 to switch the operation and the operation stop state of the compressor 541 easily and simply in a simple configuration without transmitting a signal indicating whether cooling is necessary. Controlled.

For example, the refrigerating device described in Patent Document 1 (Japanese Patent Laid-Open No. 2002-228297) is similar, and performs control to stop the compressor when the suction refrigerant pressure is lower than or equal to a predetermined value in order to avoid wet operation.

Challenge

As described above, in the refrigerating device 5, when the suction refrigerant pressure is lower than the predetermined value when the transition from the outdoor thermo-off state to the outdoor thermo-on state is controlled, the compressor is controlled not to be started. However, for example, when the outside air temperature is significantly lower than −5 ° C., the saturation pressure of the refrigerant is lowered and the refrigerant pressure in the circuit is lowered. As a result, even if the refrigerating unit 52 or the like requests cooling, the solenoid valves 513 and 523 are opened, but the compressor 541 may not be started while the suction side refrigerant pressure is lowered.

This invention is made | formed in view of this point, and the objective is to provide the refrigeration apparatus which can start a compressor smoothly even in low outdoor temperature.

Disclosure of the Invention

Solution to the Invention The present invention is as follows.

The first solution includes a heat source circuit having a high temperature side compressor 141 and a utilization circuit connected to the heat source circuit and having an evaporator 123 and a low temperature side compressor 131, and executing a vapor compression refrigeration cycle. It is assumed that the refrigeration unit. In addition, the present invention, the operation control means for switching the operation and operation stop state of the high temperature side compressor 141 based on the suction refrigerant pressure, and the evaporator (at the time of the operation stop state of the high temperature side compressor 141) And a start control means for starting the low temperature side compressor 131 so that the suction refrigerant pressure of the high temperature side compressor 141 increases when a predetermined condition including a condition relating to the cooling demand in 123 is satisfied. It is done.

In the above solution, the operation and the operation stop state of the high temperature side compressor 141 are switched based on the suction refrigerant pressure. Here, when the operation is resumed in the operation stop state of the high temperature side compressor 141, the suction of the high temperature side compressor 141 is satisfied, if a predetermined condition including a condition relating to the cooling requirement in the evaporator 123 is satisfied. The low temperature side compressor 131 is started to increase the refrigerant pressure.

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Effects of the Invention

Therefore, according to the first solution, when the operation of the high temperature side compressor 141 is resumed, if a predetermined condition including a condition relating to the cooling demand in the evaporator 123 is satisfied, the suction of the high temperature side compressor 141 is satisfied. The low temperature side compressor 131 is started before the high temperature side compressor 141 to increase the refrigerant pressure. As a result, even when the outside air temperature is significantly low, the suction refrigerant pressure of the high temperature side compressor 141 increases reliably, so that the high temperature side compressor 141 can be smoothly started.

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1 is a schematic configuration diagram of a refrigerating device according to a first embodiment of the present invention.

2 is a normal operation diagram of a refrigerating device.

3 is an operation of the freezing thermostat of the refrigeration apparatus at low ambient temperature, which is a feature of the present invention.

Fig. 4 is a block diagram schematically showing the configuration of main parts of the (outdoor) thermo-on control program executed by the control unit of the outdoor unit.

5 is a flowchart showing the processing procedure of the thermo-on control executed by the control unit of the outdoor unit.

6 is a flowchart of a process of opening and closing the refrigerating solenoid valve executed in the control unit of the refrigerating unit.

7 is a flowchart of the processing of the refrigerating solenoid valve opening and closing control executed by the control unit of the refrigerating unit.

8 is a flowchart of the processing of the booster compressor start stop control executed by the control unit of the refrigerating unit.

FIG. 9 is an operation diagram of a refrigeration thermoon at low ambient temperature of the refrigerating device according to the second embodiment. FIG.

Fig. 10 is a block diagram schematically showing the configuration of main parts of the (outdoor) thermo-on control program executed by the control unit of the outdoor unit.

11 is a flowchart showing the processing procedure of the thermo-on control executed by the control unit of the outdoor unit.

FIG. 12 is an operation diagram relating to refrigeration thermo-on at low ambient temperature of the refrigerating device according to the third embodiment. FIG.

Fig. 13 is a block diagram schematically showing the configuration of main parts of the (outdoor) thermo-on control program executed by the control unit of the outdoor unit.

14 is a flowchart showing the processing procedure of the thermo-on control executed by the controller of the outdoor unit.

Fig. 15 is a refrigerant circuit diagram for explaining the outline of operation in the conventionally used refrigeration apparatus.

Explanation of the sign

1, 2, 3: Refrigerating device

113, 213, 313: Refrigerated Evaporators

123: Cryo Evaporator

131: Booster Compressor

141, 241, 341: Variable capacity compressor

Hereinafter, the refrigerator apparatus 1, 2, 3 which is embodiment of this invention is demonstrated in detail using drawing.

1 is a diagram showing a schematic configuration of a refrigerating device 1 according to a first embodiment of the present invention.

As shown in FIG. 1, the refrigerating device 1 installed in a convenience store includes a refrigerating unit 11, a refrigerating unit 12, a booster unit 13, and an outdoor unit 14.

The refrigeration unit 11 has a refrigerated showcase that is displayed while the goods are refrigerated, the refrigeration unit 12 has a refrigerated showcase that is displayed while the goods are frozen. The booster unit 13 keeps the pressure of the refrigerant low for freezing. The outdoor unit 14 is installed outdoors to radiate heat from the refrigerant to the outside air. The refrigerating unit 11, the refrigerating unit 12, and the booster unit 13 are connected to the outdoor unit 14 in parallel to form a refrigerant circuit for executing a two-stage steam compression refrigeration cycle. do.

The refrigerating unit 11 is connected to a thermostatic expansion valve 112 for reducing the refrigerant and a refrigeration evaporator 113 for absorbing and evaporating the refrigerant from the air in the refrigerator. In addition, the refrigerating unit 11 includes a fan 115 that delivers the air in the refrigerator, which is absorbed by the refrigerating evaporator 113, toward the display shelf in the refrigerating showcase. In addition, the refrigerating unit 11 passes the refrigerant destined for the refrigerator evaporator 113 at the time of opening, and blocks the flow of the refrigerant destined for the refrigerator evaporator 113 at the time of closing, and the refrigerating solenoid valve 111; A temperature sensor 114 for detecting the temperature of the air in the reservoir is installed.

The refrigeration solenoid valve 111, the thermostatic expansion valve 112, and the refrigeration evaporator 113 are connected in series from the inflow piping 201 of the refrigerating unit 11 toward the outflow piping 202.

The refrigerating unit 12 is similarly connected to a thermostatic expansion valve 122 for reducing the refrigerant and a freezing evaporator 123 for absorbing and evaporating the refrigerant from the air in the freezer. In addition, the refrigeration unit 12 includes a fan 125 that delivers the air in the freezer, which is absorbed by the freezing evaporator 123 and cooled, toward the display shelf in the freezing showcase. In addition, the refrigerating unit 12 passes through the refrigerant directed to the freezing evaporator 123 at the time of opening, and blocks the flow of the refrigerant directed to the freezing evaporator 123 at the closing time, and the air in the reservoir. A temperature sensor 124 for detecting the temperature of is installed.

The refrigeration solenoid valve 121, the thermostatic expansion valve 122, and the freezing evaporator 123 are connected in series from the inflow pipe 203 of the refrigeration unit 12 toward the outflow pipe 204.

The booster unit 13 includes a booster compressor 131. The booster compressor 131 maintains the pressure of the refrigerant passing through the freezing evaporator 123 lower than the pressure of the refrigerant passing through the refrigeration evaporator 113.

The booster unit 13 includes a bypass passage 132 of the booster compressor 131 having the check valve 133 on the way. The bypass passage 132 is configured such that the refrigerant bypasses the booster compressor 131 and flows toward the outdoor unit 14 when the booster compressor 131 fails or stops. That is, when the booster compressor 131 is driven, the refrigerant does not flow through the bypass passage 132. The check valve 133 permits only the flow of the refrigerant from the inlet pipe 205 side of the booster unit 13 toward the outlet pipe 206 side.

The outdoor unit 14 includes a variable capacity compressor 141, a condenser 142, and a receiver 143. The variable capacity compressor 141 is configured to adjust the capacity according to the cooling load of the refrigerating unit 11 or the like. The condenser 142 is configured such that the refrigerant radiates heat to outside air to condense. The receiver 143 is for temporarily accumulating the liquid refrigerant condensed in the condenser 142. That is, in this refrigeration apparatus 1, the variable capacity compressor 141 comprises a high temperature side compressor, and the booster compressor 131 comprises a low temperature side compressor.

In addition, the outdoor unit 14 is provided with a fan 144 for introducing outside air into the condenser 142. In addition, the outdoor unit 14 is provided with a temperature sensor 145 for detecting the outside air temperature and a pressure sensor 146 for detecting the pressure of the refrigerant sucked into the variable capacity compressor 141.

The variable capacity compressor 141, the condenser 142, and the receiver 143 are connected in series from the inlet pipe 207 of the outdoor unit 14 toward the outlet pipe 208.

The outflow pipe 206 of the booster unit 13 and the outflow pipe 202 of the refrigerating unit 11 are connected to the inflow pipe 207 of the outdoor unit 14. The inflow side pipe 201 of the refrigerating unit 11 and the inflow side pipe 203 of the refrigerating unit 12 are connected to the outflow side pipe 208 of the outdoor unit 14. The outflow side pipe 204 of the refrigerating unit 12 is connected to the inflow side pipe 205 of the booster unit 13.

In addition, the outdoor unit 14 has a controller 140. The control unit 140 controls the variable capacity compressor 141 for capacity control so that the refrigerant pressure in each of the evaporators 113 and 123 is kept constant. In particular, the control by the control unit 140 according to the present invention will be described later with reference to Figs.

The refrigerating device 1 operates as shown in FIGS. 2 and 3. FIG. 2 is a view showing the normal operation of the refrigerator 1, and FIG. 3 is a view showing the operation of the refrigeration thermoon at the low outside temperature of the freezer 1, which is a feature of the present invention.

As shown in Fig. 2, in the outdoor thermo-on state driven by the variable displacement compressor 141, each of the solenoid valves 111 and 121 is opened, and the refrigerating unit 11 is in the refrigerated thermo-on state. 12) This frozen thermostat is in a state. Specifically, when the variable capacity compressor 141 is driven, the compressed refrigerant is condensed while radiating heat from the condenser 142. The condensed liquid refrigerant passes through the receiver 143 and branches into the refrigerating unit 11 and the refrigerating unit 12.

In the refrigerating unit (11), the refrigerant depressurized by the expansion valve (112) is evaporated while being absorbed by the refrigerating evaporator (113), and the air in the storage of the refrigerating showcase is cooled. In the refrigerating unit 12, the refrigerant depressurized by the expansion valve 122 is evaporated while being absorbed by the freezing evaporator 123, and the air in the storage of the freezing showcase is cooled. The refrigerant flowing out of the refrigerating unit 12 is compressed by the booster compressor 131. The refrigerant after compression is combined with the refrigerant flowing out of the refrigerating unit 11 and sucked into the variable capacity compressor 141 of the outdoor unit 14, and the circulation of these refrigerants is repeated.

When the air temperature in the reservoir in the refrigerating showcase reaches a preset target temperature, the refrigerating solenoid valve 111 is closed to block the flow of the refrigerant to the refrigerating evaporator 113 (the refrigeration thermo-off state). Similarly, when the air temperature in the reservoir in the freezer is a preset target temperature, the refrigeration solenoid valve 121 is closed and the booster compressor 131 is stopped, and the refrigerant flow to the freezing evaporator 123 is blocked (freezing thermostat). Off state). When the refrigerated thermo-off state and the refrigerated thermo-off state are set, the suction refrigerant pressure of the variable capacity compressor 141 is lowered. When the lowering of the suction refrigerant pressure is detected, the variable capacity compressor 141 is stopped to enter the outdoor thermo-off state.

In the usual case where the outside air temperature is higher than -5 ° C, the refrigeration thermo on / off is controlled by the control unit 110 of the refrigerating unit 11, and the refrigeration thermo on / off is controlled by the control unit 120 of the refrigerating unit 12, Each switch automatically. The outdoor thermo on / off is automatically switched by the control unit 140 of the outdoor unit 14 based on the state of the refrigerated thermo on / off and the frozen thermo on / off. The control unit 110 and the control unit 120 will be described later with reference to FIG. 4.

If the outside air temperature is significantly lower than -5 ° C, the difference between the inside temperature of the refrigerating unit 12 and the target temperature becomes larger than a predetermined value, so that a request for freezing thermostat occurs and the refrigeration solenoid valve 121 is opened. The suction refrigerant pressure of the capacity compressor 141 hardly rises. However, as shown in FIG. 3, the refrigerating device 1 according to the present invention is a unique control, forcibly boosting the booster compressor 131 before the variable capacity compressor 141 so that the suction refrigerant pressure of the variable capacity compressor 141 increases. ) Is activated.

That is, when the guard timer of the variable capacity compressor 141 ends, the R2 signal transmitted from the control unit 140 of the outdoor unit 14 to the control unit 120 of the refrigerating unit 12 is turned on (operation). I). In the control unit 120 of the refrigerating unit 12, when it is determined that a request for a refrigeration thermo-on has occurred based on the value of the temperature in the reservoir detected by the temperature sensor 124 (operation II), the refrigerating solenoid valve 121 is operated. It is opened (operation III).

Here, the guard timer of the variable capacity compressor 141 is a timer which is terminated in about one or two minutes from the stop of the compressor in order to prevent the compressor from being damaged by the repeated stopping of the compressor within a short time.

In general, when the refrigeration solenoid valve 121 is opened, the discharged refrigerant of the variable capacity compressor 141 flows to the suction side of the variable capacity compressor 141 through the bypass passage 132 of the booster compressor 131. As it becomes possible, the suction refrigerant pressure increases. When the increase in the suction refrigerant pressure is detected by the pressure sensor 146, the variable displacement compressor 141 is started. However, if the outside air temperature is significantly low, the suction refrigerant pressure of the variable displacement compressor 141 remains lower than the predetermined value. Thus, the control unit 120 of the refrigerating unit 12 forcibly starts the booster compressor 131 (operation IV) to increase the suction refrigerant pressure of the variable capacity compressor 141.

When the rise of the suction refrigerant pressure is detected by the pressure sensor 146 (operation V), the variable capacity compressor 141 is started based on this (operation VI).

The control in these refrigerating apparatuses 1 is demonstrated in detail using FIG. 4 thru | or FIG. 8 below.

4 is a main part of the outdoor thermo-on control program executed in the control unit 140 of the outdoor unit 14, and the control unit 140 and the refrigeration unit 11 control unit 110 and the refrigeration unit 12 control unit 120 Is a block diagram schematically showing the input / output relationship of

In the control unit 140 of the outdoor unit 14, the thermo-on control program shown in FIG. 5 is executed. In the control unit 110 of the refrigerating unit 11, the refrigerating solenoid valve opening and closing control program shown in FIG. 6 is executed. In the control unit 120 of the refrigerating unit 12, the refrigerating solenoid valve control program and the booster compressor start and stop control program shown in Figs. 7 and 8, respectively, are executed. The processes in the control units 110, 120, and 140 are executed in parallel.

As shown in FIG. 4, the control unit 140 of the outdoor unit 14 includes a solenoid valve opening and closing permission unit 1401, a compressor starting condition determining unit 1402, and a compressor starting unit 1403.

The solenoid valve opening / closing permission unit 1401 has an R1 signal and an R2 signal for permitting the opening of the solenoid valves 111 and 121 and the start of the booster compressor 131 when the guard timer of the variable displacement compressor 141 is finished. It is configured to turn on. The compressor starting condition determination unit 1402 determines whether or not the suction refrigerant pressure LP detected by the pressure sensor 146, the outside air temperature Ta detected by the temperature sensor 145, and the like are each within a predetermined range. And to determine. The compressor starting unit 1403 is configured to start the variable capacity compressor 141 when the suction refrigerant pressure LP, the outside air temperature Ta, and the like are each within a predetermined range.

The control unit 110 of the refrigerating unit 11 has a cooling request determination unit 1101 and a solenoid valve opening and closing unit 1102.

The cooling request determination unit 1101 determines whether or not the difference between the temperature in the reservoir detected by the temperature sensor 114 and the preset target temperature is equal to or greater than a predetermined value (whether or not there is a refrigeration thermo-on request). The cooling request determination unit 1101 also determines whether the R1 signal is in an on state. The solenoid valve opening / closing part 1102 is configured to open the refrigerating solenoid valve 111 when there is a refrigerating thermo-on request and the R1 signal is on.

The control unit 120 of the refrigerating unit 12 includes a cooling request determination unit 1201, a solenoid valve opening and closing unit 1202, and a booster compressor starting and stopping unit 1203.

The cooling request determination unit 1201 determines whether the difference between the inside temperature of the storage detected by the temperature sensor 124 and the target temperature is equal to or larger than a predetermined value (whether there is a request for a refrigeration thermo-on). The cooling request determination unit 1201 also determines whether the R2 signal is in an on state. The solenoid valve opening and closing portion 1202 is configured to open the refrigerating solenoid valve 121 when there is a refrigeration thermo-on request and the R2 signal is on. The booster compressor actuation stop section 1203 is configured to activate the booster compressor 131 when a freezing thermo-on request is made and the R2 signal is turned on.

Here, mainly, the compressor starting condition determination unit 1402 and the compressor starting unit 1403 constitute operation control means for switching the operation (thermo on) and the pause (thermo off) of the variable capacity compressor 141. The cooling request determination unit 1201, the solenoid valve opening and closing unit 1202, and the booster compressor actuation stop unit 1203 have a cooling request of the refrigeration unit 12 when the variable displacement compressor 141 stops. When a predetermined condition such as guard timer termination of the variable capacity compressor 141 is satisfied, the start control means for starting the booster compressor 131 is configured.

Therefore, according to the programs executed in the controllers 110, 120, and 140, the booster compressor 131 is started even when the outside air temperature is low and the suction refrigerant pressure of the variable capacity compressor 141 is (locally) decreased. As a result, the suction refrigerant pressure of the variable displacement compressor 141 can be forcibly increased. Specifically, the following processing procedure is executed.

As shown in FIG. 5, in the thermo-on control by the control unit 140 of the outdoor unit 14, first, it is determined whether or not the guard timer of the variable capacity compressor 141 is finished (step 111, the following steps to ST). Notation). If the guard timer has not ended (NO in ST111), this processing ends as it is. When the guard timer is finished (YES in ST111), the R1 signal for allowing the opening of the refrigerating solenoid valve 111 and the R2 signal for permitting the opening of the refrigerating solenoid valve 121 and the booster compressor 131 are turned on. (ST112).

Subsequently, it is determined whether the suction refrigerant pressure LP of the variable displacement compressor 141 is greater than 0.25 MPa (ST113), and if the suction refrigerant pressure LP is greater than 0.25 MPa (YES in ST113), the variable displacement compressor 141 is determined. ) Is activated (ST114), and this processing ends.

If the suction refrigerant pressure LP is 0.25 MPa or less (NO in ST113), the outside air temperature Ta detected by the temperature sensor 145 is lower than -5 ° C and the stop time of the variable capacity compressor 141 is 10 minutes. It is determined whether or not it is abnormal (ST115). If this condition is satisfied (YES in ST115), the variable capacity compressor 141 is forcibly started in ST114. If the outside air temperature Ta is equal to or higher than -5 ° C or the stop time of the variable capacity compressor 141 is less than 10 minutes (NO in ST115), this process is terminated.

By these processes, even when the suction refrigerant pressure LP is low and the variable capacity compressor 141 cannot be started, when the guard timer is terminated, the R1 signal and the R2 signal are turned on, and the respective control units 110 and 120 are turned on. The opening of the solenoid valves 111 and 121 and the starting of the booster compressor 131 are allowed.

As shown in FIG. 6, in the refrigerating solenoid valve opening / closing control by the control unit 110 of the refrigerating unit 11, first, a difference between the inside temperature of the reservoir detected by the temperature sensor 114 and the preset target temperature is equal to or greater than a predetermined value. It is determined whether or not a refrigerated thermo-on request has occurred (ST121). If a refrigeration thermo-on request does not occur (NO in ST121), the refrigeration solenoid valve 111 remains closed (ST122), and this process is complete | finished.

If a refrigerated thermo on request occurs (YES in ST121), it is determined whether the R1 signal is on (ST123). If the R1 signal is not turned on (NO in ST123), the refrigeration solenoid valve 111 remains closed in ST122, and this processing ends. If the R1 signal is in the ON state (YES in ST123), the refrigerating solenoid valve 111 is opened (ST124), and this processing ends.

As shown in FIG. 7, in the refrigeration solenoid valve opening / closing control by the control part 120 of the refrigerating unit 12, the same process as the said refrigeration solenoid valve opening / closing control is performed. That is, if the refrigeration thermo-on request has not occurred (NO at ST131) or the R2 signal is OFF (NO at ST133) based on the temperature detection in the reservoir by the temperature sensor 124, the refrigeration solenoid valve 121 Is closed (ST132), and this process is complete | finished. When the freezing thermo-on request occurs and the R2 signal is on (YES in ST131 and YES in ST133), the refrigeration solenoid valve 121 is opened (ST134), and the process is terminated.

As shown in Fig. 8, in the booster compressor start stop control by the control unit 120 of the refrigerating unit 12, if a refrigeration thermo-on request has not occurred (NO in ST141), or the R2 signal is off (ST143). NO), the booster compressor 131 is stopped (ST142) and the process ends. When the freezing thermo-on request occurs and the R2 signal is on (YES in ST141 and YES in ST143), the booster compressor 131 is started (ST144), and the process is terminated.

In general, when the refrigerating solenoid valve 121 is opened by the refrigerating solenoid valve opening and closing, and the refrigerant is able to circulate in the refrigerant circuit, the suction refrigerant pressure of the variable displacement compressor 141 is increased, and the thermo-on control is performed. Based on the determination in ST113, the variable capacity compressor 141 is started. However, if the outside air temperature is low, the suction refrigerant pressure hardly rises, and thus the variable capacity compressor 141 cannot be started.

Therefore, in the refrigerating device 1, the booster compressor 131 is started by the booster compressor actuation stop control, so that the suction refrigerant pressure of the variable capacity compressor 141 can be increased. Therefore, the variable capacity compressor 141 can be reliably started on the basis of the judgment in ST113 of the thermo-on control. That is, by these controls, the variable capacity compressor 141 can be smoothly started even when the outside air temperature is low.

Next, the freezing apparatus 2 which is 2nd Embodiment of this invention and the freezing apparatus 3 which is 3rd Embodiment are demonstrated. These refrigeration apparatuses 2 and 3 omit the refrigeration unit and the booster unit in the first embodiment. In the description of these refrigerators 2 and 3, the same reference numerals are given to the components having the same performance as the refrigerator 1 of the first embodiment, and detailed description thereof will be omitted.

9 is a view showing an operation relating to the refrigerated thermo-on at the low outside air temperature of the freezer 2.

In the refrigerating device 2, when the guard timer of the compressor 241 is finished, the R1 signal transmitted from the control unit 240 of the outdoor unit 24 to the control unit 210 of the refrigerating unit 21 is turned on (operation I). . When the controller 210 of the refrigerating unit 21 determines that a refrigerating thermo-on request has occurred based on the value of the temperature in the storage detected by the temperature sensor 214 (operation II), the solenoid valve 211 opens. (Operation III).

Here, when the outside air temperature is low, the outside air temperature is detected by the temperature sensor 245, thereby lowering the threshold value of the suction refrigerant pressure which is a criterion for determining whether to activate the compressor 241 (operation IV). When the suction refrigerant pressure detected by the pressure sensor 246 satisfies the threshold value after the change (operation V), the compressor 241 is started (operation VI).

Such control will be described in detail with reference to FIGS. 10 and 11.

FIG. 10 is a block diagram schematically showing the configuration of main parts of a thermo-on control program executed by the control unit 240 of the outdoor unit 24. As shown in FIG. Specifically, the control unit 240 executes the thermo-on control program as shown in FIG. 11, and the control unit 210 of the refrigerating unit 21 executes the refrigerating solenoid valve opening and closing control program similar to FIG. 6.

The control unit 240 of the outdoor unit 24 includes a solenoid valve opening and closing unit 2401, a compressor starting condition changing unit 2402, a compressor starting condition determining unit 2403, and a compressor starting unit 2404. .

When the guard timer of the compressor 241 ends, the solenoid valve opening and closing part 2401 turns on the R1 signal for allowing the opening of the solenoid valve 211. The compressor starting condition changing unit 2402 lowers the threshold value of the suction refrigerant pressure for starting the compressor 241 based on the outdoor air temperature Ta detected by the temperature sensor 245. The compressor starting condition determining unit 2403 determines whether or not the suction refrigerant pressure LP detected by the pressure sensor 246 is within a predetermined range. The compressor starting part 2404 starts the compressor 241 when the suction refrigerant pressure LP is a value within a predetermined range.

The control unit 210 of the refrigerating unit 21, like the refrigerating device 1 of the first embodiment, determines whether there is a refrigerating thermo-on request and also determines whether the R1 signal is on. A determination unit 2101 and a solenoid valve opening and closing portion 2102 for opening the refrigerating solenoid valve 211 when the refrigerating thermo-on request is made and the R1 signal is turned on.

Here, mainly, the compressor starting condition determination unit 2403 and the compressor starting unit 2404 constitute operation control means for switching the operation and the operation stop state of the compressor 241. The compressor starting condition changing unit 2402 comprises reference changing means for lowering the threshold value of the suction refrigerant pressure, which is a criterion for determining whether to start the operation of the compressor 241 when the outside air temperature is lower than the predetermined temperature.

Therefore, according to the programs executed in the controllers 210 and 240, even when the suction refrigerant pressure of the compressor 241 is lowered due to the low outside temperature, the threshold of the suction refrigerant pressure is lowered to reliably start the compressor 241. You can. Specifically, the following processing procedure is executed. Herein, the refrigerating solenoid valve opening and closing control executed by the control unit 210 of the refrigerating unit 21 is the same as that of FIG.

As shown in FIG. 11, in the thermo-on control by the control part 240 of the outdoor unit 24, it is first determined whether the guard timer of the compressor 241 is complete | finished (ST201). If the guard timer has not ended (NO in ST201), this processing is terminated as it is, and if the guard timer has ended (YES in ST201), the R1 signal for allowing the opening of the refrigerating solenoid valve 211 is turned on (ST202).

Subsequently, it is determined whether the suction refrigerant pressure LP of the compressor 241 is greater than 0.4 MPa (ST203). If the suction refrigerant pressure LP is larger than 0.4 MPa (YES in ST203), the compressor 241 is started. (ST204) This processing ends.

If the suction refrigerant pressure LP is 0.4 MPa or less (NO in ST204), it is determined whether the outside air temperature Ta is lower than 0 ° C and the suction refrigerant pressure LP is larger than 0.25 MPa (ST205). If this condition is satisfied (YES in ST205), the compressor 241 is started in ST204, and the present process ends.

If the conditions of ST205 are not satisfied, i.e., if the outside air temperature Ta is 0 ° C or more or the suction refrigerant pressure LP is 0.25 MPa or less (NO in ST205), the outside air temperature Ta is lower than -5 ° C and It is determined whether the suction refrigerant pressure LP is greater than 0.2 MPa (ST206). If this condition is satisfied (YES in ST206), the compressor 241 is started in ST204, and this process ends. If the outside air temperature Ta is equal to or higher than -5 ° C or the suction refrigerant pressure LP is equal to or lower than 0.2 MPa (NO in ST206), the compressor 241 is terminated without starting the compressor.

In these processing procedures, when the R1 signal is turned on in ST202 and a refrigeration thermo-on request is generated on the refrigerating unit 21 side, the refrigerating solenoid valve 211 opens. However, when the outside air temperature is low, the suction refrigerant pressure of the compressor 241 remains substantially lowered even when the refrigerating solenoid valve 211 is opened. Thus, by decreasing the threshold value of the suction refrigerant pressure for starting the compressor 241 from 0.4 MPa to 0.25 MPa, 0.2 MPa in accordance with the amount of the outside air temperature is lowered to 0 ° C and -5 ° C at a predetermined reference temperature, Promote the start of the compressor 241. That is, these controls can smoothly start the compressor 241 even when the outside air temperature is low.

FIG. 12 is a diagram showing an operation relating to the refrigerated thermo-on at the low outside temperature of the refrigerating device 3 according to the third embodiment.

In the refrigerating device 3, when the guard timer of the compressor 341 ends, the R1 signal transmitted from the control unit 340 of the outdoor unit 34 to the control unit 310 of the refrigerating unit 31 is turned on (operation). I). In the control unit 310 of the refrigerating unit 31, if it is determined that a refrigerating thermo-on request has been generated based on the temperature in the reservoir detected by the temperature sensor 314 (operation II), the refrigerating solenoid valve 311 is opened. (Operation III).

Since the saturation pressure of the refrigerant is lowered when the outside air temperature is low, the suction refrigerant pressure of the compressor 341 remains substantially lowered even when the refrigerating solenoid valve 311 is opened. Thus, in the present freezer 3, when it detects that the outside air temperature is low (operation IV), the imaging energization to the motor of the compressor 341 is started (operation V). Here, phase conduction energization is to supply a current to the motor by phase-forming one phase of three-phase alternating current so as to generate the coil and use it as a heater without rotating the motor.

By this phase conduction, the refrigerant temperature in the stopped compressor 341 rises, and the refrigerant saturation pressure near the suction port of the compressor 341 increases. Therefore, when the suction refrigerant pressure detected by the pressure sensor 346 rises and a predetermined pressure condition is satisfied (operation VI), the compressor 341 is started (operation VII).

The control in the refrigerating device 3 will be described with reference to FIGS. 13 and 14.

FIG. 13 is a block diagram schematically showing the configuration of main parts of a thermo-on control program executed by the control unit 340 of the outdoor unit 34. As shown in FIG. The thermo-on control program as shown in FIG. 14 is executed in the control unit 340 of the outdoor unit 34, and the refrigerating solenoid valve opening and closing control program similar to FIG. 6 is executed in the control unit 310 of the refrigerating unit 31. .

The control unit 340 of the outdoor unit 34 includes a solenoid valve opening and closing unit 3401, an open-cell communication battery unit 3402, a compressor starting condition determining unit 3403, and a compressor starting unit 3404.

The solenoid valve opening and closing permission unit 3401 turns on the R1 signal for allowing the opening of the refrigerated solenoid valve 311 when the guard timer of the compressor 341 ends. The image forming battery timing unit 3402 instructs the image conducting current based on the outside air temperature Ta detected by the temperature sensor 345. The compressor starting condition determining unit 3403 determines whether or not the suction refrigerant pressure LP detected by the pressure sensor 346 is within a predetermined range. The compressor starting unit 3404 starts the compressor 341 when the suction refrigerant pressure LP is within a predetermined range.

The control unit 310 of the refrigerating unit 31, like the refrigerating unit 1 of the first embodiment, determines whether there is a refrigerating thermo-on request and at the same time determines whether the R1 signal is on. 3101, and a solenoid valve opening and closing portion 3102 for opening the refrigerating solenoid valve 311 when the refrigerating thermo-on request and the R1 signal are on.

Here, mainly, the compressor starting condition determination unit 3403 and the compressor starting unit 3404 constitute operation control means for switching the operation and the operation stop state of the compressor 341. In the case of the idle state of the compressor 341, when the external air temperature is lower than the predetermined temperature and the refrigeration thermo-on is requested, the phase-opening battery-time part 3402 is connected to the motor of the compressor 341 so that the suction refrigerant pressure is increased. An energization control means for executing phase conduction is constituted.

Therefore, according to the programs executed in the controllers 310 and 340, even when the refrigerating solenoid valve 311 is opened, even when the inlet refrigerant pressure of the compressor 341 is low due to low outside air temperature, the motor of the compressor 341 is provided. It is possible to forcibly raise the suction refrigerant pressure of the compressor 341 by conducting an open phase. Specifically, the following processing procedure is executed. In addition, the refrigeration solenoid valve opening / closing control performed by the control part 310 of the refrigerating unit 31 is the same as that of FIG. 6, and description is abbreviate | omitted.

As shown in Fig. 14, in the thermo-on control by the control unit 340 of the outdoor unit 34, first, it is determined whether or not the guard timer of the compressor 341 is finished (ST301). If the guard timer has not ended (NO in ST301), this processing is terminated as it is, and if the guard timer has ended (YES in ST301), the R1 signal permitting the opening of the refrigerating solenoid valve 311 is turned on (ST302). ).

Subsequently, it is determined whether the suction refrigerant pressure LP of the compressor 341 is greater than 0.25 MPa (ST303). If the suction refrigerant pressure LP is larger than 0.25 MPa (YES in ST303), after the phase conduction is inhibited and normal energization is set to be executed (ST304), the compressor 341 is started (ST305) and the process is terminated.

If the suction refrigerant pressure LP is 0.25 MPa or less (NO in ST303), it is determined whether the outside air temperature Ta is lower than -5 ° C and the imaging conduction time is 5 minutes or longer (ST306). Here, if the outside air temperature Ta is -5 ° C or higher or the phase conduction time is less than 5 minutes (NO in ST306), the outside air temperature Ta is lower than -5 ° C and the stop time of the compressor 341 is 5 minutes. It is determined whether or not it is abnormal (ST307).

In ST307, if the outside air temperature Ta is lower than -5 DEG C and the stop time of the compressor 341 is 5 minutes or more (YES in ST307), phase conduction is permitted (ST308), and the flow returns to ST301 (start of control). Goes. Thereafter, the process proceeds from ST301 to ST303, and again it is determined whether the suction refrigerant pressure LP of the compressor 341 is larger than 0.25 MPa. Here, if the suction refrigerant pressure LP is larger than 0.25 MPa due to phase open current (YES in ST303), as described above, after phase open current is prohibited (ST304), the compressor 341 is started (ST305). It ends.

That is, in ST307, if the outside air temperature Ta is lower than -5 ° C and 5 minutes have elapsed since the compressor 341 is stopped in the thermo-off state, the refrigerant temperature in the compressor 341 is considered to be considerably lowered. Perform open phase conduction.

On the other hand, in ST303, if the suction refrigerant pressure LP is 0.25 MPa or less despite the phase conduction energization (NO in ST303), the outside air temperature Ta is again lower than -5 ° C in ST306 and the imaging conduction time is 5 It is determined whether or not more than minutes. If this condition is satisfied here (YES in ST306), the process proceeds to ST304 and ST305, whereby the compressor 341 is started and the present process ends. Conversely, if the condition is not satisfied (NO in ST306), the process proceeds back to ST307. That is, in ST306, although the suction refrigerant pressure LP did not reach the predetermined pressure because the outside air temperature was low, the suction refrigerant pressure LP is considered to have risen slightly to start the compressor 341 when the phase conduction energization is performed for a predetermined time.

In ST307, when the outside air temperature Ta is lower than -5 ° C or the stop time of the compressor 341 is less than 5 minutes (NO in ST307), the phase-opening current is not allowed again and returns to ST301 (start of control). Goes. Thereafter, the process is implemented as described above.

In these processing procedures, the R1 signal is turned on in ST302, and the refrigerating solenoid valve 311 opens when a refrigeration thermo-on request occurs. In this case, when the outside air temperature is low, the suction refrigerant pressure of the compressor 341 remains lowered. However, by performing phase open current to the motor of the compressor 341, the suction refrigerant pressure of the compressor 341 can be forcibly increased. The compressor 341 can be reliably started.

In the refrigerating device of the above embodiment, the drop is detected by directly detecting only the outside air temperature using the temperature sensors 145, 245, and 345. However, in the present invention, for example, the coolant temperature in the vicinity of the discharge port of the high pressure dome compressors 141, 241 and 341 may be detected. In this case, for example, when it is determined that the outside temperature is low when the coolant temperature near the discharge port is 20 ° C. or lower, even if one of the two temperature sensors is broken, the drop in the outside temperature can be reliably detected.

In the refrigerating devices 1, 2, and 3 of the above embodiments, an electromagnetic valve and an expansion valve are used to control the refrigerant flow rate from the refrigerating units 11, 21, 31 and the refrigerating unit 12 side. I made it. However, instead of this, other valves such as electromagnetic expansion valves may be used to control the valves to open at the time of thermo-on. In this case, similarly to the opening of the solenoid valve described above, the refrigerant can be circulated in the circuit only by starting the compressor by the opening of the solenoid expansion valve.

The above embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its application, or its use.

As described above, the present invention is useful for a refrigerating device including a compressor whose operation and shutdown are switched based on the elevation of the suction refrigerant pressure.

Claims (4)

A refrigeration apparatus (1) comprising a heat source circuit having a high temperature side compressor 141 and a use circuit connected to the heat source circuit and having an evaporator 123 and a low temperature side compressor 131, and executing a vapor compression refrigeration cycle. To Operation control means for switching the operation and the operation stop state of the high temperature side compressor 141 based on the suction refrigerant pressure; When the high temperature side compressor 141 is in an operation stop state, when a predetermined condition including a condition relating to a cooling demand in the evaporator 123 is satisfied, the suction refrigerant pressure of the high temperature side compressor 141 is increased. And a start control means for starting the low temperature side compressor (131). delete delete delete

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