JPS63243659A - Refrigerator for refrigerator truck - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a refrigeration system for a refrigerated vehicle, and more particularly to a refrigeration system equipped with an oil separator on the discharge side of a compressor of a refrigeration cycle.

(Prior Art) In general, in a refrigerated truck, as shown in FIG. 3, a compressor 32 driven by the engine 31 is disposed near the engine 31, and a condenser unit (condenser) 33 is installed outside the refrigerator. A cooling unit (evaporator) 34 is provided inside each of them. The compressor 32, condenser unit 33, cooling unit 34, etc. form a refrigeration cycle as shown in FIG. 4.

That is, the high-temperature, high-pressure gas refrigerant discharged from the compressor 32 is guided to the condenser unit 33 and liquefied there, further passes through the liquid tank 35 and the dryer 36 and is depressurized by the expansion valve 37, and then is transferred to the cooling unit 3.
It is vaporized at step 4. After that, the refrigerant is transferred to the accumulator 38
and from there it is sucked into the compressor 32.

By the way, since oil is usually mixed in the gas refrigerant discharged from the compressor 32, an oil separator 39 is provided between the discharge side of the compressor 32 and the condenser unit 33 in order to separate this oil. The oil separator 39 separates the gas refrigerant from the oil, and the gas refrigerant is introduced into the condenser unit 33, while the separated oil is returned to the low pressure case of the compressor 32 or connected to the suction pipe through the oil return pipe 40. He had been returned to the department.

(Problems to be Solved by the Invention) However, the following problems have conventionally occurred in connecting the oil return pipe 40 from the oil separator 39 to the compressor 32.

■ The connection of the oil return pipe 40 to the compressor 32 was complicated and required time; ■ The compressor 32
There is a risk that the oil return pipe 40 may break due to photographing.
It was necessary to provide the oil return pipe 40 with an anti-vibration structure. (1) Since the high temperature oil discharged from the compressor 32 returns, the case temperature of the compressor 32 increases, which has an adverse effect on the compressor 32.

SUMMARY OF THE INVENTION It is thus an object of the present invention to provide a refrigeration system for a refrigerated vehicle that can solve the problems of the prior art described above and can easily return oil from an oil separator without adversely affecting the compressor.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the refrigeration system for a refrigerated vehicle of the present invention has an accumulator connected to the suction side of the compressor in the refrigeration cycle, and an accumulator connected to the discharge side of the refrigeration cycle. In a refrigeration system for a refrigerated vehicle connected to an oil separator for separating oil from refrigerant gas, an oil return pipe from the oil separator is connected to the accumulator.

(Function) In this way, by connecting the oil return pipe from the oil separator to the accumulator instead of the compressor, the oil return pipe is no longer directly subjected to the vibrations of the compressor, and there is no need for a vibration-proof structure.

In addition, the high temperature oil discharged from the compressor is guided to the accumulator via the oil separator.
The oil is here cooled by the return refrigerant before returning to the compressor, eliminating any negative effects on the compressor. Furthermore, at this time, since the return refrigerant entering the accumulator is heated by the high temperature oil, its complete evaporation is promoted and liquid back-up is prevented.

(Example) Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a configuration diagram of a refrigeration cycle used in a refrigeration system for a refrigerated vehicle according to an example of the present invention.

An oil separator 2 is provided on the discharge side of the compressor 1, and a condenser unit 3 is connected to the oil separator 2. The condenser unit 3 has a liquid tank 4. A dryer 5 and an expansion valve 6 are connected in sequence, and a cooling unit 7 is connected to the expansion valve 6. Furthermore, an accumulator 8 is installed in the cooling unit 7.
is connected and the 7 cumulator 8 is connected to the compressor 1.
are connected to the suction side of the refrigeration cycle.

Further, an oil return pipe 9 for guiding the oil separated by the oil separator 2 is connected between the oil separator 2 and the accumulator 8.

Note that the compressor 1 is an engine of a refrigerating vehicle (not shown).
The cooling unit 7 is installed inside the refrigerator, and the condenser unit 3 is installed outside the refrigerator.

Next, the operation of this embodiment will be described.

First, when compressor 1 is driven, compressor 1
Oil is discharged together with high-temperature and high-pressure gas refrigerant, and these are separated into gas refrigerant and oil by an oil separator 2. The gas refrigerant is led to a condenser unit 3 and liquefied there, then passes through a liquid tank 4 and a dryer 5, is depressurized by an expansion valve 6, becomes a mist, and is vaporized in a cooling unit 7. As a result, the inside of the refrigerator will be cooled. Thereafter, the vaporized refrigerant is guided to the accumulator 8.

On the other hand, the oil separated from the gas refrigerant by the oil separator 2 passes through the oil return pipe 9 and enters the accumulator 8, where it is temporarily stored. At this time, the oil led to the accumulator 8 is in a high temperature state because it is discharged from the compressor 1, and heat exchange occurs between this oil and the return refrigerant led to the accumulator 8 from the cooling unit 7. It is done. That is, while the high temperature oil is cooled, the return refrigerant is heated. Therefore, complete evaporation of the return refrigerant is promoted.

Thereafter, an appropriate amount of oil cooled by the return refrigerant is sucked into the compressor 1 from the accumulator 8 along with the vaporized return refrigerant.

In this way, the refrigeration cycle is operated without any adverse effect on the compressor 1 due to the return of high temperature oil, and while effectively preventing liquid back up.

In addition, as in the refrigerated car shown in FIG.
In this case, as shown in Fig. 2, a compressor 11 driven by an in-fabric power supply is installed in parallel with the compressor 1 on the engine side, and both compressors are selectively connected between the accumulator 8 and the oil separator 2. By connecting to the refrigeration system, refrigeration operation can be performed even when the engine is stopped.

[Effects of the Invention] As explained above, according to the present invention, the following excellent effects are exhibited.

(1) Since the oil return pipe from the oil separator is connected to the 7-cumulator, the connection work becomes easy and the oil return pipe is not directly affected by the vibrations of the compressor. That is, the risk of breakage of the oil return pipe is reduced, and there is no need for a vibration-proof structure.

(2) Since the oil once cooled in the accumulator returns to the compressor, the temperature of the compressor case does not rise and adversely affect the compressor.

(3) Complete evaporation of the returning refrigerant is promoted, and liquid back-up is effectively prevented.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a refrigeration cycle used in a refrigeration system for a refrigerated vehicle according to an embodiment of the present invention, Fig. 2 is a block diagram of a refrigeration cycle showing another embodiment, and Fig. 3 is a general diagram of a refrigeration cycle. FIG. 4 is a schematic configuration diagram of a refrigerating vehicle, and FIG. 4 is a configuration diagram of a refrigeration cycle showing a conventional example. In the figure, 1 is a compressor, 2 is an oil separator, 8 is an accumulator, and 9 is an oil return pipe.

Claims (1)

[Claims] In a refrigeration system for a refrigerated vehicle, in which an accumulator is connected to the suction side of the compressor in the refrigeration cycle, and an oil separator for separating oil from refrigerant gas is connected to the discharge side, an oil return pipe from the oil separator is connected. A refrigeration system for a refrigerated vehicle, characterized in that it is connected to the above accumulator.