JPH07139827A - Cooling and freezing device - Google Patents

Abstract

PURPOSE:To prevent a cooling capability of a refrigerant evaporator for use in cooling operation from being reduced by a method wherein the refrigerant is bypassed from an evaporating pressure adjusting valve under a single cooling operation mode. CONSTITUTION:A refrigerant evaporator 12 for use in cooling operation and a refrigerant evaporator 20 for use in a refrigerator are connected in parallel with one refrigerant compressor 2. An evaporating pressure adjusting valve 13 is connected to a low pressure side from an outlet port of the refrigerant evaporator 12 for use in cooling operation under a simultaneous cooling and refrigerating operation mode, a large amount of refrigerant is circulated within the refrigerant evaporator 20 for use in refrigerating operation with the refrigerant evaporator 12 for use in cooling operation under a metering action of the evaporating pressure adjusting valve 13 so as to improve a freezing capability. Refrigerant gas flowed out of the outlet port of the refrigerant evaporator 12 for use in cooling operation is passed through a bypassing flow passage 14 connected in parallel with the evaporating pressure adjusting valve 13 and then a cooling capability is improved by circulating a large amount of refrigerant within the refrigerant evaporator 12 for use in cooling operation under an arrangement in which an influence of the metering action of the evaporating pressure adjusting valve 13 is not applied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling / refrigerating apparatus suitable for a refrigerating vehicle refrigerating apparatus or a refrigerating vehicle cooling / refrigerating apparatus in which two refrigerant evaporators are connected in parallel to one refrigerant compressor. It is a thing.

[0002]

2. Description of the Related Art As a conventional technique, as shown in FIG. 3, a cooling and refrigerating apparatus 100 in which a cooling refrigerant evaporator 102 and a refrigerating refrigerant evaporator 103 are connected in parallel to one refrigerant compressor 101 is provided. Are known. This cooling / refrigerating apparatus 100
Is a refrigerant compressor 101, a refrigerant condenser 104, a receiver 105, a cooling expansion valve 106, a cooling refrigerant evaporator 1
02 and an evaporation pressure adjusting valve 107 connected in series in order, and a refrigeration unit 11 in which a refrigeration expansion valve 109 and a refrigeration refrigerant evaporator 103 are connected in series in order.
It is composed of 0s.

In the cooling and refrigerating apparatus 100, the cooling unit 108 and the refrigerating unit 110 are respectively provided with solenoid valves 11 and 11.
Since 1 and 112 are provided, it is possible to selectively switch to the cooling / refrigerating simultaneous operation mode, the cooling only operation mode, and the cooling only operation mode.

[0004]

However, in the conventional cooling / refrigerating apparatus 100, in order to improve the refrigerating capacity of the refrigerating refrigerant evaporator 103, the cooling refrigerant evaporator 102 is provided.
The evaporation pressure control valve 107 is connected to the low pressure side from the outlet of
The evaporation temperature in the cooling refrigerant evaporator 102 is forcibly raised. As a result, in the cooling only operation mode, the flow rate of the refrigerant is smaller than that in the refrigeration cycle that does not have the evaporation pressure adjusting valve, so that the evaporation temperature in the cooling refrigerant evaporator 102 does not decrease. Therefore, in the cooling only operation mode, there is a problem that the cooling capacity of the cooling refrigerant evaporator 102 decreases.

An object of the present invention is to provide a cooling / refrigerating device capable of preventing a decrease in cooling capacity of a cooling refrigerant evaporator in a cooling only operation mode.

[0006]

According to the present invention, there is provided a cooling unit in which a cooling expansion valve, a cooling refrigerant evaporator, and an evaporation pressure adjusting valve are sequentially connected in series, a freezing expansion valve and a freezing refrigerant evaporator. A refrigeration unit connected in series in order,
A cooling / refrigerating simultaneous operation mode in which a refrigerant is circulated in both the cooling unit and the refrigeration unit and a cooling single operation mode in which a refrigerant is circulated only in the cooling unit are provided, and an outlet of the refrigerant condenser and refrigerant compression are provided. In a cooling / refrigerating device in which the cooling unit and the refrigerating unit are connected in parallel between the inlet of the machine and the cooling unit, the cooling unit includes an outlet of the cooling refrigerant evaporator and an inlet of the refrigerant compressor. Between the bypass flow path connected in parallel to the evaporation pressure adjusting valve, and the opening and closing means for opening the bypass flow path in the single cooling operation mode and closing the bypass flow path in the simultaneous cooling and refrigeration operation mode. Adopted.

[0007]

According to the present invention, when the switching means switches to the simultaneous cooling / freezing operation mode, the opening / closing means closes the bypass passage. Then, the refrigerant gas discharged from the refrigerant compressor is condensed in the refrigerant condenser and supplied to both the cooling unit and the refrigeration unit. The refrigerant flowing out from the outlet of the refrigerant condenser is mainly supplied into the refrigeration unit by the throttling action of the evaporation pressure adjusting valve. The refrigerant supplied to the cooling unit is adiabatically expanded by the cooling expansion valve, evaporated in the cooling refrigerant evaporator at the evaporation temperature subjected to the throttling action of the evaporation pressure adjusting valve, and passes through the evaporation pressure adjusting valve. Returned to the refrigerant compressor. On the other hand, the refrigerant supplied to the refrigerating unit is adiabatically expanded by the freezing expansion valve and evaporated in the freezing refrigerant evaporator at an evaporation temperature lower than that of the cooling refrigerant evaporator. As a result, a sufficient refrigerating capacity can be obtained in the refrigerating refrigerant evaporator.

When the switching means switches to the cooling only operation mode, the opening / closing means opens the bypass passage. Then, the refrigerant gas discharged from the refrigerant compressor is condensed in the refrigerant condenser and is supplied only to the cooling unit. The refrigerant supplied to the cooling unit is adiabatically expanded by the cooling expansion valve, evaporated in the cooling refrigerant evaporator without being affected by the throttling action of the evaporating pressure control valve, and passes through the bypass flow path to compress the refrigerant. Returned to the plane. Therefore, in the cooling only operation mode, since it is not affected by the throttling action of the evaporation pressure control valve,
As the flow rate of the refrigerant passing through the cooling refrigerant evaporator increases, the evaporation temperature in the cooling refrigerant evaporator falls below that in the simultaneous cooling / freezing operation mode. As a result, a sufficient cooling capacity can be obtained in the cooling refrigerant evaporator.

[0009]

【Example】

[Configuration of Embodiment] Next, an explanation will be given based on an embodiment in which the cooling / refrigerating apparatus of the present invention is applied to a cooling / refrigerating apparatus for refrigerating vehicles. 1 and 2 show an embodiment of the present invention, and FIG. 1 is a view showing a refrigerating machine for refrigerating vehicles. This refrigeration vehicle cooling / refrigerating apparatus 1 includes one refrigerant compressor 2 and one refrigerant compressor 1.
One refrigerant condenser 3, one receiver 4, cooling unit 5
From the refrigeration unit 6 and the like, a refrigeration cycle 7 as a heat source for refrigeration in the cabin of the refrigeration vehicle and in the refrigerator
Are configured.

The refrigerant compressor 2 is rotatably driven by a drive device (not shown) such as an engine or an electric motor mounted on a refrigerating vehicle, and compresses the refrigerant sucked from the suction port to generate a high-temperature, high-pressure gas refrigerant. Discharge from the discharge port. The refrigerant compressor 2 increases the flow rate of the refrigerant in the refrigeration cycle 7 as the rotation speed of the drive device increases. Further, as the refrigerant compressor, a variable capacity type compressor that changes the flow rate of the refrigerant based on the heat load of the refrigerating vehicle such as the cooling load or the refrigerating load may be used even if the rotation speed of the drive device does not change.

The refrigerant condenser 3 is a heat exchanger that is installed in a place where the running air of the refrigerating vehicle is easily received and that condenses the gas refrigerant flowing from the refrigerant compressor 2 by receiving the airflow of the cooling fan 8. The receiver 4 separates the refrigerant that has flowed in from the refrigerant condenser 3 into gas-liquid and temporarily stores the refrigerant, and only the liquid refrigerant is cooled by the cooling unit 5 or the refrigeration unit based on the heat load of the refrigerating vehicle such as a cooling load or a freezing load. Outflow to 6. In addition, instead of the receiver 4 as a gas-liquid separator, a cooling unit 5
An accumulator may be arranged between the outlet of the refrigerant compressor 6 and the outlet of the refrigeration unit 6.

The cooling unit 5 includes an electromagnetic switching valve (hereinafter abbreviated as electromagnetic valve) 9 and an electromagnetic on-off valve (hereinafter abbreviated as electromagnetic valve) 1.
0, a temperature-controlled expansion valve for cooling (hereinafter abbreviated as expansion valve for cooling) 11, a refrigerant evaporator for cooling 12, and an evaporation pressure adjusting valve 13 are connected in series in order. The solenoid valve 9 is the switching means of the present invention, is installed at the inlet of the cooling unit 5, and opens when energized to circulate the refrigerant in the cooling unit 5.

The solenoid valve 10 is the opening / closing means of the present invention. The solenoid valve 10 is installed in the bypass passage 14 and opens when energized to circulate the refrigerant in the bypass passage 14. Detour flow path 1
4 is the outlet of the cooling refrigerant evaporator 12 and the evaporation pressure adjusting valve 1
3 has a branch port between the evaporating pressure adjusting valve 13 and the outlet of the evaporating pressure adjusting valve 13 and a suction port of the refrigerant compressor 2 and is connected in parallel to the evaporating pressure adjusting valve 13. It is a flow path.

The cooling expansion valve 11 includes a throttle valve (not shown) for adjusting the opening of a small hole, a heat-sensitive cylinder 15 for detecting the temperature of the refrigerant flowing out from the outlet of the cooling-refrigerant evaporator 12, and this heat-sensitive cylinder. A capillary tube 16 for transmitting a pressure corresponding to the refrigerant temperature detected by the cylinder 15 to the main body side is provided.

The cooling expansion valve 11 rapidly expands by injecting the high-temperature, high-pressure liquid refrigerant flowing from the receiver 4 from a small hole of the throttle valve. Further, the cooling expansion valve 11 adjusts the opening degree of a small hole of the throttle valve based on the degree of superheat at the outlet of the cooling refrigerant evaporator 12 so that the evaporation of the refrigerant at the outlet of the cooling refrigerant evaporator 12 is completed. The flow rate of the refrigerant in the refrigeration cycle 7 is controlled to control the flow rate.

The cooling refrigerant evaporator 12 is housed in a duct (not shown) installed on the front side of the refrigerating vehicle, receives the air blown by the fan 17, and flows in from the outlet of the expansion valve 11 for cooling. It is a heat exchanger that evaporates the refrigerant. In addition,
The air cooled by heat exchange with the refrigerant is supplied to the fan 17
By being blown into the cabin of the refrigerating vehicle, the room temperature in the cabin of the refrigerating vehicle is cooled to a set temperature (for example, 25 ° C.).

The evaporation pressure adjusting valve 13 is connected to a lower pressure side than the outlet of the cooling refrigerant evaporator 12, and controls the flow rate of the refrigerant by adjusting the opening of a throttle hole (not shown) to control the cooling refrigerant evaporator 12. Evaporation pressure at the set value (eg 2.0 kg
/ Cm ² ) or more to prevent frost of the refrigerant evaporator 12 for cooling. When the evaporation pressure adjusting valve 13 is operated in the cooling / refrigerating simultaneous operation mode, the evaporating pressure of the evaporation force adjusting valve 13 causes the refrigerant to flow mainly from the outlet of the receiver 4 to the refrigerating unit 6.

The refrigerating unit 6 is the refrigerating unit of the present invention, and includes an electromagnetic switching valve (hereinafter abbreviated as electromagnetic valve) 18, a temperature-controlled expansion valve for refrigeration (hereinafter abbreviated as expansion valve for refrigeration) 19
Further, the refrigerating refrigerant evaporator 20 is connected in series in order.
The solenoid valve 18 is the switching means of the present invention, is installed at the inlet of the refrigeration unit 6, and opens when energized to circulate the refrigerant in the refrigeration unit 6.

The refrigerating expansion valve 19 is the freezing expansion valve of the present invention, and like the cooling expansion valve 11, is provided with a throttle valve (not shown), a heat sensitive cylinder 21, a capillary tube 22 and the like, and a receiver. The high-temperature, high-pressure liquid refrigerant flowing in from the outlet of No. 4 is expanded. The refrigeration expansion valve 19 controls the flow rate of the refrigerant by adjusting the opening degree of a small hole of the throttle valve based on the degree of superheat at the outlet of the refrigeration refrigerant evaporator 20.

The refrigerating refrigerant evaporator 20 is the refrigerating refrigerant evaporator of the present invention. The refrigerating refrigerant evaporator 20 is housed in a refrigerator (not shown) installed on the rear side of the refrigerating vehicle and receives the air blown by the fan 23. , A heat exchanger that evaporates the atomized refrigerant that has flowed in from the outlet of the refrigeration expansion valve 19. The air cooled by heat exchange with the refrigerant is refrigerated so that the internal temperature of the refrigerator of the refrigerating vehicle is equal to or lower than a set temperature (for example, 5 ° C). Here, refrigerated foods such as agricultural products, livestock products, and marine products are generally stored in the refrigerator.

Next, the control circuit of the refrigerating / cooling apparatus 1 for a refrigerating vehicle will be described with reference to FIG. Each solenoid valve 9, 10,
Control of energization and de-energization of 18 is performed by the control circuit 24. The control circuit 24 includes a computer 25, relay coils 26 to 28, relay switches 29 to 31 and the like.

The computer 25 uses the setting state of the operation mode changeover switch 32, the temperature detected by the room temperature sensor 33,
And the energization control of the relay coils 26 and 27 is performed based on the temperature detected by the internal temperature sensor 34. The operation mode changeover switch 32 is an independent cooling operation mode in which the liquid refrigerant flowing out from the outlet of the receiver 4 is supplied only to the cooling unit 5,
The liquid refrigerant flowing out from the outlet of the receiver 4 is stored in the refrigeration unit 6
It is a switch for switching between the refrigerating single operation mode in which only the refrigerating operation is performed and the liquid cooling medium flowing out from the outlet of the receiver 4 is simultaneously supplied to both the cooling unit 5 and the refrigerating unit 6 in the simultaneous cooling and refrigerating operation mode.

The room temperature sensor 33 is, for example, a thermistor, and detects the room temperature in the cabin of the refrigerating vehicle.
This detected temperature is converted into an electric signal (for example, voltage value) and sent to the computer 25. The in-compartment temperature sensor 34 uses, for example, a thermistor, detects the in-compartment temperature in the refrigerator of the refrigerating car, converts the detected temperature into an electric signal (for example, voltage value), and sends it to the computer 25.

The relay coil 26 closes the relay switch 29 when energized. Further, the relay coil 27 is
When energized, the relay switch 30 is closed. And
When the relay coil 28 is energized, the relay switch 31
Open up. The relay switch 29 is connected to the solenoid valve 9 and the relay switch 31, the relay switch 30 is connected to the solenoid valve 18 and the relay coil 28, and the relay switch 31 is connected to the solenoid valve 10.

The operation of the computer 25 will be described below with reference to Table 1. First, in the cooling only operation mode, the detected temperature of the indoor temperature sensor 33 is the set temperature (for example, 25 ° C.).
If the temperature is rising above, the relay coil 26 is turned on, the relay coil 27 is turned off, the solenoid valves 9 and 10 are energized as shown in Table 1, and the energization to the solenoid valve 18 is stopped. Cooling only operation mode (A)}. When the temperature detected by the indoor temperature sensor 33 is lower than the set temperature,
Both the relay coils 26 and 27 are turned off to stop energizing the solenoid valves 9, 10 and 18 as shown in Table 1 (cooling independent operation mode (B)).

Next, in the refrigeration single operation mode, if the temperature detected by the internal temperature sensor 34 is higher than the set temperature (for example, 5 ° C.), the relay coil 26 is turned off and the relay coil 27 is turned on. As shown in Table 1, the solenoid valve 18
Only the current is energized {refrigerator alone operation mode (A)}. Also,
When the temperature detected by the internal temperature sensor 34 is lower than the set temperature, both the relay coils 26 and 27 are turned off,
As shown in Table 1, the energization of the solenoid valves 9, 10 and 18 is stopped {refrigeration single operation mode (B)}.

Next, in the cooling / refrigerating simultaneous operation mode, when both the temperature detected by the indoor temperature sensor 33 and the temperature detected by the internal temperature sensor 34 are higher than the set temperature, both relay coils 26 and 27 are turned on. Then, as shown in Table 1, the solenoid valves 9 and 18 are energized and the solenoid valve 10 is deenergized {cooling / refrigerating simultaneous operation mode (A)}. When the detected temperature of the indoor temperature sensor 33 is higher than the set temperature and the detected temperature of the inside temperature sensor 34 is lower than the set temperature, as shown in Table 1, the cooling single operation mode ( The same control as in A) is performed {cooling / refrigerating simultaneous operation mode (B)}.

When the temperature detected by the indoor temperature sensor 33 is lower than the set temperature and the temperature detected by the internal temperature sensor 34 is higher than the set temperature in the simultaneous cooling and refrigerating operation mode, Table 1 The same control as the refrigerating single operation mode (A) is performed as shown in {Cooling and refrigerating simultaneous operation mode (C)}. If the temperature detected by the room temperature sensor 33 and the temperature detected by the room temperature sensor 34 are both below the set temperature, both relay coils 26 and 27 are turned off,
As shown in Table 1, the energization of the solenoid valves 9, 10, 18 is stopped {cooling / refrigerating simultaneous operation mode (D)}.

[Table 1]

Here, in Table 1, the solenoid valves 9, 10,
The open circles in 18 represent open valves, and the open circles represent closed valves. Further, ◯ of the indoor temperature sensor 33 and the inside temperature sensor 34 represents a state in which the detected temperature is higher than the set temperature, and x represents a state in which the detected temperature is lower than the set temperature.

[Operation of Embodiment] Next, the operation of the refrigerating / cooling apparatus 1 for a refrigerating vehicle will be briefly described with reference to FIGS. 1 and 2. When the operation mode changeover switch 32 is switched to the cooling / refrigerating simultaneous operation mode and both the temperature detected by the indoor temperature sensor 33 and the temperature detected by the in-compartment temperature sensor 34 are higher than the set temperature, the results are shown in Table 1. As described above, the solenoid valves 9 and 18 are energized, the solenoid valves 9 and 18 are opened, and the solenoid valve 10 is closed, so that the control in the cooling and refrigeration simultaneous operation mode (A) is performed.

At this time, the high-temperature, high-pressure refrigerant gas discharged from the refrigerant compressor 2 flows into the refrigerant condenser 3 and exchanges heat with the air blown by the cooling fan 8 to be condensed and become a liquid refrigerant. Then, the liquid refrigerant once flows into the receiver 4, and then flows into the cooling unit 5 and the refrigeration unit 6, respectively.

The liquid refrigerant flowing into the cooling unit 5 flows through the electromagnetic valve 9 into the cooling expansion valve 11, and when it passes through the cooling expansion valve 11, it is rapidly injected by being injected from a small hole. Adiabatically expands to a low-temperature, low-pressure atomized refrigerant. Then, the atomized refrigerant flows into the cooling refrigerant evaporator 12, exchanges heat with the air blown by the fan 17 to evaporate to become a refrigerant gas, and since the electromagnetic valve 10 is closed, the evaporation pressure is adjusted. It is returned to the refrigerant compressor 2 through the inside of the valve 13.

By the throttle action of the evaporation pressure adjusting valve 13, the evaporation pressure in the cooling refrigerant evaporator 12 is set high, and the evaporation temperature is forcibly raised. Therefore, the flow rate of the refrigerant passing through the cooling refrigerant evaporator 12 is small, and the cooling capacity in the cabin of the refrigerating vehicle is somewhat suppressed.

On the other hand, the liquid refrigerant flowing into the refrigerating unit 6 passes through the electromagnetic valve 18 into the refrigerating expansion valve 19, and is jetted from a small hole when passing through the refrigerating expansion valve 19. Rapidly adiabatically expands to a low-temperature, low-pressure atomized refrigerant. Then, the atomized refrigerant flows into the refrigerating refrigerant evaporator 20, exchanges heat with the air in the refrigerator blown by the fan 23 and evaporates to become refrigerant gas,
It is returned to the refrigerant compressor 2.

By continuing the above operation, the inside of the cabin of the refrigerating vehicle is cooled and the inside of the refrigerator is refrigerated. Further, since the evaporation pressure adjusting valve 13 forcibly raises the evaporation temperature in the cooling refrigerant evaporator 12 of the cooling unit 5, the liquid refrigerant flowing out from the receiver 4 mainly flows into the refrigeration unit 6. As a result, the refrigerating refrigerant evaporator 2
At 0, a sufficient refrigerating capacity is obtained.

When the refrigeration single operation mode is switched by the operation mode changeover switch 32 and the temperature detected by the internal temperature sensor 34 is higher than the set temperature (for example, 5 ° C.), as shown in Table 1. Since only the solenoid valve 18 is energized and only the solenoid valve 18 is opened and the solenoid valves 9 and 10 are both closed, the control in the refrigeration single operation mode (A) is performed.

As a result, the refrigerant gas discharged from the refrigerant compressor 2 is condensed in the refrigerant condenser 3 and separated into gas and liquid by the receiver 4, and then only the liquid refrigerant is closed by the solenoid valve 9. Only flows into the refrigeration unit 6. Therefore, the flow rate of the refrigerant passing through the refrigerating refrigerant evaporator 20 increases,
The evaporation pressure and evaporation temperature in the refrigerating refrigerant evaporator 20 are further lowered, and the refrigerating capacity is improved.

When the operation mode changeover switch 32 is used to switch to the cooling only operation mode and the temperature detected by the indoor temperature sensor 33 rises above the set temperature (for example, 25 ° C.), as shown in Table 1, The solenoid valves 9 and 10 are energized, the solenoid valves 9 and 10 are opened, and the solenoid valve 18 is closed, so that control in the cooling only operation mode (A) is performed.

As a result, the refrigerant gas discharged from the refrigerant compressor 2 is condensed in the refrigerant condenser 3 and separated into gas and liquid by the receiver 4, and only the liquid refrigerant is closed by the electromagnetic valve 18, so that Only flows into the cooling unit 5.

The liquid refrigerant flowing into the cooling unit 5 flows through the electromagnetic valve 9 into the cooling expansion valve 11, and adiabatically expands when passing through the cooling expansion valve 11 and then the cooling refrigerant evaporator. Flows into 12. Then, the refrigerant that has flowed into the cooling refrigerant evaporator 12 exchanges heat with air to be evaporated into refrigerant gas without being affected by the throttling action of the evaporation pressure adjusting valve 13.

The refrigerant gas flowing out from the cooling refrigerant evaporator 12 is returned to the refrigerant compressor 2 through the bypass passage 14 because the electromagnetic valve 10 is open. Further, in the cooling only operation mode, the flow rate of the refrigerant passing through the inside of the cooling refrigerant evaporator 12 is increased because it is not affected by the throttling action of the evaporation pressure adjusting valve 13, and the evaporation pressure in the cooling refrigerant evaporator 12 is increased. The evaporation temperature is lower than that in the simultaneous cooling and refrigeration operation mode.

[Effects of Embodiment] As described above, the refrigerating machine 1 for refrigerating vehicles operates in the same manner as a single refrigerating cycle which is not affected by the throttling action of the evaporative pressure adjusting valve 13 in the cooling single operation mode. To do. As a result, in the cooling refrigerant evaporator 12, as compared with the conventional cooling and refrigerating apparatus 100 in which the evaporation pressure in the cooling refrigerant evaporator 102 is forcibly raised by the evaporation pressure adjusting valve 107 and the cooling capacity is lowered. The evaporation temperature can be lowered, and the cooling capacity can be improved to the same level as a single refrigeration cycle without the evaporation pressure adjusting valve 107. Further, as the amount of refrigerant returned to the refrigerant compressor 2 increases, the amount of refrigerating machine oil circulating in the refrigeration cycle 7 together with the refrigerant to the refrigerant compressor 2 also increases. Therefore, seizure and the like in the refrigerant compressor 2 can be prevented.

As another method for preventing a decrease in the amount of refrigerating machine oil returned in the cooling only operation mode, a method for returning refrigerating machine oil to the refrigerant compressor 2 even if the throttle valve of the cooling expansion valve 11 is excessively throttled. Bleed port and notch to expansion valve 11 for cooling
Although there is a conventional method of providing the throttle valve in No. 2, the selection work for optimizing the diameter and number of bleed ports and notches becomes very complicated. On the other hand, in this embodiment, the bypass flow path 14 bypassing the evaporation pressure adjusting valve 13 in the cooling only operation mode and the solenoid valve 10 opening / closing the bypass flow path 14 are provided to reduce the return amount of the refrigerating machine oil. Since it is possible to prevent the deterioration, it is not necessary to provide such a bleed port or notch, so that it is not necessary to perform selection work.

As a conventional technique, a cooling unit,
FIR type refrigerating cycle in which two electromagnetic valves respectively arranged in the refrigerating unit are turned on and off at predetermined time intervals (for example, 10 seconds) to circulate the refrigerant alternately between the cooling refrigerant evaporator and the refrigerating refrigerant evaporator alternately. There is. However, in such an FIR type refrigeration cycle, there is a problem that the method of controlling the two solenoid valves by the computer becomes complicated. On the other hand, in this embodiment, since the operations of the solenoid valves 10 and 18 may be controlled to be reversed, the computer 2
The method of controlling the solenoid valves 9 and 18 by 5 is very simple and inexpensive.

[Modification] In this embodiment, the present invention is applied to the refrigerating machine 1 for refrigerating vehicles, but the present invention may be applied to a refrigerating apparatus for refrigerating vehicles, or as a heat source for refrigeration or ice making. The refrigerator with an ice maker using a refrigeration cycle may be applied to a vehicle cooling and refrigerating device provided in a vehicle compartment.

In this embodiment, the solenoid valves 9 and 18 are provided at the inlet side of the cooling unit 5 and the inlet side of the cooling unit 6, respectively, as switching means for switching between the simultaneous cooling and refrigerating operation mode and the independent cooling operation mode. The switching means may be provided anywhere in the unit 5 and the refrigeration unit 6. The solenoid valve 9 may be omitted and only the solenoid valve 18 may be provided. In addition, the cooling unit 5 and the refrigeration unit 6
A three-way switching valve may be provided at a branch point or a connection point with.

In this embodiment, the solenoid valve 10 is provided as the opening / closing means for opening / closing the bypass passage 14, but a three-way switching valve may be provided at the branch point or the connection point of the bypass passage 14 as the opening / closing means. Further, instead of the solenoid valves 9, 10, 18, a valve device or the like that opens and closes by manual operation may be used.

In this embodiment, the operation mode changeover switch 32 as the instruction means is used to instruct the operation mode. However, a detection means for detecting the cooling load or the refrigeration load is provided, and the detection value of the detection means is detected. Alternatively, the operation mode may be automatically selected.

[0049]

According to the present invention, the evaporation pressure adjusting valve is connected to the low pressure side from the outlet of the cooling refrigerant evaporator in the simultaneous cooling / refrigeration operation mode, and the evaporation in the cooling refrigerant evaporator is performed by the throttling action of the evaporation pressure adjusting valve. Raising the temperature. Therefore, the refrigerant flowing out from the outlet of the refrigerant condenser is mainly supplied to the refrigeration unit, so that the refrigerating capacity of the refrigerant evaporator for refrigeration can be improved.

Further, according to the present invention, even when the evaporation pressure adjusting valve is connected to the low pressure side from the outlet of the cooling refrigerant evaporator, the refrigerant is circulated by bypassing the evaporation pressure adjusting valve in the cooling only operation mode. The cooling refrigerant evaporator is not affected by the throttling action of the evaporation pressure adjusting valve. Therefore, since the evaporation temperature in the cooling refrigerant evaporator can be lowered in the cooling only operation mode, it is possible to obtain a sufficient cooling capacity in the cooling refrigerant evaporator.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a unit diagram showing a control circuit used in an embodiment of the present invention.

FIG. 3 is a configuration diagram showing a cooling and refrigerating apparatus used as a conventional technique.

[Explanation of symbols]

 1 Refrigerator Refrigerator (Refrigerator / Refrigerator) 2 Refrigerant Compressor 3 Refrigerant Condenser 5 Refrigerator Unit 6 Refrigerator Unit (Refrigerator Unit) 7 Refrigeration Cycle 9 Solenoid Valve (Switching Means) 10 Electromagnetic Valve (Opening / Closing Means) 11 For Cooling Expansion valve 12 Refrigerant evaporator for cooling 13 Evaporation pressure adjustment valve 14 Detour flow path 18 Electromagnetic valve (switching means) 19 Expansion valve for refrigeration (expansion valve for refrigeration) 20 Refrigerant evaporator for refrigeration (refrigeration evaporator for refrigeration) 32 Operation Mode selector switch

Claims (1)

[Claims] 1. A cooling unit comprising a cooling expansion valve, a cooling refrigerant evaporator and an evaporation pressure adjusting valve connected in series in order.
A refrigerating unit in which a freezing expansion valve and a refrigerating refrigerant evaporator are sequentially connected in series, a cooling / refrigerating simultaneous operation mode in which a refrigerant is circulated in both the cooling unit and the refrigerating unit, and a refrigerant is circulated only in the cooling unit. A cooling / refrigerating apparatus comprising: a switching unit that switches between an independent cooling operation mode, and the cooling unit and the refrigeration unit connected in parallel between an outlet of the refrigerant condenser and an inlet of the refrigerant compressor. The unit has a bypass flow path connected in parallel to the evaporation pressure adjusting valve between the outlet of the cooling refrigerant evaporator and the suction port of the refrigerant compressor, and the bypass flow path in the cooling only operation mode. A cooling / refrigerating apparatus having an opening / closing means that opens and closes the bypass passage in the simultaneous cooling / refrigerating operation mode.