JPH10205955A - Refrigerating device for transport - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the damage of loads due to vapor condensation by providing a high pressure gas bypass circuit to introduce the hot gas into an inlet of an evaporator through a directional control valve on an operation panel, and controlling the directional control valve and a condenser fan by the operation of a heating operation switch to raise the in-box temperature close to the outside air temperature. SOLUTION: A condenser inlet solenoid valve 12 is arranged on a refrigerant pipe leading from a compressor 3 to a condenser 4, and an evaporator inlet solenoid valve 13 is arranged on a high pressure gas refrigerant bypass pipe 60 which is branched from the refrigerant piping leading to the inlet solenoid valve 12 and the compressor 3 and connected to an inlet part an evaporator 9. When a heating operation switch 16 provided on an operation panel 15 is turned ON while a refrigerating device is operated, the inlet solenoid valves 12, 13 are opened/closed, a condenser fan motor 14 is turned OFF, and the box is heated inside in the heating operation. When the heating operation switch 16 is turned OFF when the in-box temperature is same as the outside air temperature, the solenoid valves are opened/closed, and the condenser fan motor 14 is turned ON, and the cooling operation is restored.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transportation refrigeration system.

[0002]

2. Description of the Related Art FIGS. 3 and 4 show an example of a conventional transport refrigeration system (hereinafter, abbreviated as a refrigeration system). FIG. 3 is an overall equipment diagram, and FIG. 4 is a system diagram showing an overall configuration of a refrigeration apparatus. 3 and 4, the operation of the refrigerating apparatus is turned on by the operation panel 15, and the compressor 3 disposed in the condensing unit 1 installed outside the freezer 100 is driven by the power of an engine or the like (not shown). When driven, the high-pressure and high-temperature gas refrigerant compressed by the compressor 3 is sent to the condenser 4 under pressure, where it is cooled and condensed and liquefied by the outside air introduced by the condenser fan 5. After leaving the condenser 4, the liquid refrigerant passes through the receiver 6 and the dryer 7, and is arranged in the evaporator unit 2 by the high-pressure refrigerant pipe 40 connecting the condensing unit 1 and the evaporator unit 2 installed in the freezer 100. In the process of being sent to the expansion valve 8 and being adiabatically expanded and entering the evaporator 9 and flowing through the piping in the evaporator 9, the evaporator fan 10 exchanges heat with the circulating air in the freezer 100 sent into the evaporator 9, Cool the circulating air. The cooled air is
The cooling air C is blown out from the outlet of the evaporator unit 2 into the freezer 100 by the evaporator fan 10 to cool the freezer 100. The refrigerant that has exchanged heat with the circulating air in the freezer 100 by the evaporator 9 evaporates and evaporates, and passes through the low-pressure refrigerant pipe 50 connecting the evaporator unit 2 and the condensing unit 1 to the accumulator 11 arranged in the condensing unit 1. Sent,
From here, it returns to the compressor 3.

[0003] In the freezer 100, there is a case where an insulated cargo A cooled in advance by a commercial power supply and a non-insulated cargo B such as miscellaneous cargo are sometimes mixed, but in the case of long-time transportation, the temperature of the insulated cargo A increases. Therefore, the non-cooled cargo B in the freezer 100 is cooled at the same time. During the operation of the refrigeration system, the temperature inside the freezer 100 is detected by the temperature sensor 17 inside the refrigerator and displayed on the operation panel 15 or the like.

[0004]

Conventionally, in the transportation of a cold storage cargo A and a non-refrigerated cargo B such as miscellaneous cargo in a freezer, the cold storage cargo A is placed in a cold storage box pre-cooled by a commercial power supply before transportation. It is stored and loaded in the freezer. In the case of transport for a long time, in order to prevent the temperature of the insulated cargo A in the insulated box from rising, the refrigerator of the freezer is cooled and transported together with the non-insulated cargo B while being cooled in the freezer. For this reason, the non-refrigerated cargo B is cooled to a temperature considerably lower than the outside air temperature in the freezer, and when the non-refrigerated cargo B is unloaded, dew condensation occurs on the non-refrigerated cargo B, and the cargo is damaged. was there.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks of the prior art, and aims to prevent damage to the cargo due to dew condensation that occurs when the non-cooled cargo is unloaded by unloading the non-cooled cargo before unloading the cargo. .

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and relates to a transportation refrigeration system having the following features.

(1) An evaporator unit having an evaporator and an evaporator fan and installed in a refrigerator,
In a transport refrigeration system in which a refrigeration cycle is formed by connecting a pipe between a compressor, a condenser and a condensing unit having a condenser fan, hot gas between the compressor and the condenser is supplied to the evaporator inlet via a switching valve. A high-pressure gas bypass circuit leading to the air conditioner is provided, and a heating operation switch is provided on the operation panel. By operating the heating operation switch, the switching control of the switching valve and the on / off control of the condenser fan are performed. The heater can be heated to a temperature equal to the outside air temperature detected by the sensor.

(2) In the transportation refrigeration system described in the above item (1), the heating operation of the heating operation switch causes
Output to the switching valve driving means and the condenser fan motor driving means, perform switching control of the switching valve and on / off control of the condenser fan, so that a deviation from the outside air temperature detected by the outside air temperature sensor becomes a predetermined value or less. Equipped with a controller to control the temperature inside the refrigerator.

[0009]

FIG. 1 is an overall equipment diagram and a system diagram showing an overall configuration of a refrigeration apparatus according to a first embodiment of the present invention. In the drawing, a condenser inlet solenoid valve 12 is provided in a refrigerant pipe from the compressor 3 to the condenser 4, and a high pressure gas refrigerant branched from the refrigerant pipe from the compressor 3 and the condenser inlet solenoid valve 12 to the inlet of the evaporator 9. The bypass pipe 60 is connected, and the evaporator inlet solenoid valve 13 is disposed in the high-pressure gas refrigerant bypass pipe 60. When the heating operation switch 16 provided on the operation panel 15 is turned on during operation of the refrigeration apparatus, the solenoid valve relays 19 and 20 and the fan motor relay 21 operate,
Since the condenser inlet solenoid valve 12 is closed, the evaporator inlet solenoid valve 13 is opened, and the condenser fan motor 14 is turned off, the high-pressure high-temperature gas refrigerant compressed by the compressor 3 flows from the compressor 3 to the high-pressure gas refrigerant bypass pipe 6.
The operation is switched to the heating operation in which the pressure is sent to the evaporator 9 via 0. In the process of flowing through the evaporator 9, the high-temperature and high-pressure gas refrigerant exchanges heat with the circulating air from the freezer 100 sent into the evaporator 9 by the evaporator fan 10, and the circulating air is heated by the evaporator fan 10. Heated air is blown out from the outlet of the evaporator unit 2 into the freezer 100 to heat the freezer 100.

The operation panel 15 is equipped with a temperature sensor 17 installed in the freezer 100 and a temperature display panel 22 for displaying each temperature detected by an outside air temperature sensor 18 installed outside the freezer 100. . When the heating operation switch 16 is turned off when the temperature in the freezer 100 rises to the same level as the outside air temperature by the temperature display panel 22, the condenser inlet solenoid valve 12 is opened, the evaporator inlet solenoid valve 13 is closed, and the condenser fan motor When 14 is turned on, the refrigeration apparatus returns from the heating operation to the cooling operation. Other configurations and operations are the same as those of the conventional example shown in FIGS. 3 and 4, and corresponding members are denoted by the same reference numerals.

In the present embodiment, when the insulated cargo A and the non-insulated cargo B are mixed and transported for a long time, a high-pressure / high-temperature gas refrigerant from the condensing unit is supplied to the evaporator unit to the refrigeration unit, and the inside of the freezer is supplied. The refrigeration system is switched to heating operation by turning on the heating operation switch provided on the operation panel a predetermined time before unloading non-refrigerated cargo such as miscellaneous cargo in the cargo by the heating operation device for heating. When raising the temperature and unloading,
Since the temperature in the freezer and the temperature of the uncooled cargo can be heated to the same temperature as the outside air temperature, the problem of cargo damage due to dew condensation when unloading is solved. In addition, since the heating operation switch is manually operated, even when the outside air temperature sensor is not installed, the same effect as the above can be expected in practical use.

FIG. 2 is an overall equipment diagram and a system diagram showing an overall configuration of a refrigeration apparatus according to a second embodiment of the present invention. In FIG. 2, when the heating operation switch 16 provided on the operation panel 15 is turned on, the temperature controller 23
Receives the ON command of the heating temperature switch 16 and outputs it to the solenoid valve relays 19 and 20 and the fan motor relay 21 to close the condenser inlet solenoid valve 12, open the evaporator inlet solenoid valve 13 and open the condenser fan motor 14. OFF
Is switched to the heating operation. When the temperature in the freezer 100 increases due to the heating operation of the refrigeration apparatus, and the deviation between the output value of the internal temperature sensor 17 and the output value of the outside air temperature sensor 18 becomes equal to or less than a specified value, the temperature control controller 23 Output to the solenoid valve relays 19 and 20 and the fan motor relay 21 to open the condenser inlet solenoid valve 12, close the evaporator inlet solenoid valve 13, turn on the condenser fan motor 14, return the refrigerator to the cooling operation, and heat The operation switch 16 is reset to the OFF state. Other configurations and operations are the same as those of the first embodiment, and corresponding members are denoted by the same reference numerals.

In this embodiment, when the heating operation switch is turned on, the temperature controller causes the temperature in the freezer to change.
Since the control is accurately maintained at the same level as the outside air temperature, the first
The same effects as in the embodiment can be obtained.

[0014]

In the transport refrigeration system of the present invention, a high-pressure gas bypass circuit for guiding hot gas between the compressor and the condenser to the evaporator inlet through a switching valve is provided, and a heating operation switch is provided on the operation panel. Provided,
By operating the heating operation switch, the switching control of the switching valve and the on / off control of the condenser fan are performed,
Since the inside temperature can be heated to the same temperature as the outside temperature detected by the outside temperature sensor, the freezer temperature is raised a certain time before unloading uncooled cargo such as miscellaneous cargo among the cargo. In addition, it is possible to prevent damage to the cargo due to dew condensation that occurs when unloading a non-cooled cargo.

[Brief description of the drawings]

FIG. 1 is an overall equipment diagram and a system diagram showing an overall configuration of a land transportation refrigeration apparatus according to a first embodiment of the present invention.

FIG. 2 is an overall equipment diagram and a system diagram showing an overall configuration of a refrigeration apparatus for land transportation according to a second embodiment of the present invention.

FIG. 3 is an overall equipment diagram of a conventional land transportation refrigeration system.

FIG. 4 is a system diagram showing an overall configuration of the refrigeration apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS A Insulated cargo B Non-insulated cargo 1 Condensing unit 2 Evaporator unit 3 Compressor 4 Condenser 5 Condenser fan 6 Receiver 7 Dryer 8 Expansion valve 9 Evaporator 10 Evaporator fan 11 Accumulator 12 Capacitor solenoid valve 13 Evaporator inlet solenoid valve 14 Condenser fan motor 15 Operation panel 16 Heating operation switch 17 Inside temperature sensor 18 Outside temperature sensor 19, 20 Solenoid valve relay 21 Fan motor relay 22 Temperature display panel 23 Temperature controller 40 High pressure refrigerant pipe 50 Low pressure refrigerant pipe 60 High pressure gas refrigerant pipe 100 Freezer

Claims (2)

[Claims] 1. A transportation for forming a refrigeration cycle by connecting a pipe between an evaporator unit having an evaporator and an evaporator fan and being installed in a refrigerator, and a condensing unit having a compressor, a condenser and a condenser fan. In the refrigerating apparatus, a high-pressure gas bypass circuit for guiding hot gas between the compressor and the condenser to the evaporator inlet through a switching valve is provided, and a heating operation switch is provided on an operation panel, and the heating operation switch is operated by operating the heating operation switch. A refrigerating apparatus for transporting, wherein switching control of a switching valve and on / off control of the condenser fan are performed so that the inside temperature can be heated to the same temperature as the outside air temperature detected by an outside air temperature sensor. 2. A heating operation of the heating operation switch outputs a signal to the switching valve driving means and a condenser fan motor driving means to perform switching control of the switching valve and on / off control of the condenser fan, thereby controlling an outside air temperature. 2. The transport refrigeration system according to claim 1, further comprising a controller that controls the internal temperature so that a deviation from the outside air temperature detected by the sensor is equal to or less than a predetermined value.