JPH0424471A - Refrigerating cycle - Google Patents

Abstract

PURPOSE:To eliminate the reverse flow of refrigerant solution into a compressor even when a heater is started after defrosting by a method wherein a check valve is provided in the suction side pipeline of the compressor and an additional accumulator, conducting refrigerant from lower side to upper side, is arranged between the evaporator of a refrigerant pipeline and the accumulator of the same pipeline. CONSTITUTION:When defrosting operation is started, refrigerant, positioned in an evaporator, is heated by a heater device and is guided into an additional accumulator 22. The refrigerant is separated into liquid refrigerant and gas refrigerant during moving through the additional accumulator from the lower part to the upper part while the liquid refrigerant is reserved in the accumulator 22 and the gas refrigerant is guided into an accumulator 5, then, is returned into a compressor 1 through a check valve 20 and a pipeline 21. Upon starting refrigerating cycle, liquid refrigerant overflowed in the accumulator 22 is guided to and reserved into the accumulator 5 whereby the reverse flow of the liquid refrigerant into the compressor 1 will never be generated. Upon defrosting operation immediately after starting control, the gas refrigerant, flowing reversely from the compressor 1 toward the accumulator 5, will never be returned into the accumulator 5 by the check valve 20.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a refrigeration cycle that ensures the reliability of a compressor.

(Prior Art) As shown in FIG. 5, the refrigeration cycle of a typical refrigerator, etc. is constructed by sequentially connecting a compressor 1, a condenser 2, an expansion device 3, an evaporator 4, and an accumulator 5 with a refrigerant pipe 6. There is.

As shown in FIG. 6, in the accumulator 5, the internal space of the accumulator body 7 is divided into two upper and lower chambers by a partition plate 8, and an inlet pipe 10 is connected to the upper chamber 9, and a lower chamber 11
The discharge side piping 12 is connected to the accumulator body 13, as shown in FIG. It is known that it is composed of

The accumulator 5 separates the liquid component in the suction gas led from the evaporator 4, causes only vapor to be sucked into the compressor 1, and functions to prevent liquid back up when the control is activated.

(Problem to be Solved by the Invention) In the above-mentioned type of refrigeration cycle, if frost forms on the evaporator during continuous operation and the efficiency of the evaporator decreases, it is necessary to defrost the evaporator. The evaporator is defrosted by heating the evaporator with a heater, but heating the evaporator means that the refrigerant inside the evaporator is also warmed, and the warmed and gasified refrigerant passes through the accumulator and enters the suction pipe. If the refrigerant is condensed and liquefied, the refrigerant will liquefy back into the compressor when it is started, worsening the reliability of the compressor.

In addition, when defrosting operation is performed immediately after starting the control, the liquid refrigerant from the time of control still remains in the accumulator, and this liquid refrigerant is at the lowest temperature, so the gas flowing back from the compressor A large amount of refrigerant becomes stagnant, and when restarted, this refrigerant overflows the accumulator and backs up, worsening the reliability of the compressor.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a refrigeration cycle that eliminates liquid back-up during defrosting of a heater and significantly improves the reliability of a compressor.

[Structure of the invention]

(Means for Solving the Problems) The refrigeration cycle of the present invention includes a compressor, a condenser,
The expansion device, evaporator, and accumulator are connected in sequence with refrigerant piping, and a check valve is provided between the compressor and accumulator, and an inlet is installed on the bottom between the evaporator and accumulator of the refrigerant piping so that the refrigerant flows from the bottom to the top. and an additional accumulator with an outlet on the upper side.

(Function) In the refrigeration cycle of the present invention, when the evaporator is heated with a heater to defrost the evaporator, the refrigerant warmed within the evaporator is guided to the additional accumulator, where the liquid refrigerant is The gas refrigerant accumulates in the additional accumulator, passes through this additional accumulator, is led to the accumulator, and from there returns to the compressor via the suction pipe.Therefore, at the end of the defrosting operation, the liquid refrigerant accumulates in the additional accumulator, so the liquid refrigerant The liquid refrigerant does not accumulate in the accumulator or suction pipe, and the liquid refrigerant that overflows in the additional accumulator at startup is stored in the accumulator, so the liquid refrigerant does not back up to the compressor and deteriorate the reliability of the compressor.

In addition, when defrosting operation is performed immediately after control activation, the gas refrigerant flowing back from the compressor is prevented from returning to the accumulator by a check valve installed between the compressor and the accumulator. A portion of the liquid refrigerant returned from the evaporator will remain, and the liquid refrigerant will not overflow from the accumulator and back into the compressor at the time of restart.

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

In FIG. 1, the same members as in FIG. 5 are given the same reference numerals.

In FIG. 1, reference numeral 20 indicates a check valve, and this check valve 2
0 is provided in the suction side pipe 21 connecting the compressor 1 and the accumulator 5 to prevent gas refrigerant flowing back from the compressor 1 from returning to the accumulator 5. Further, an additional accumulator 22 is arranged between the evaporator 4 and the accumulator 5 of the refrigerant pipe 6.

The additional accumulator 22 has an inlet 23 on the lower side and an outlet 24 on the upper side, as shown in FIG. Divided into two upper and lower chambers by 25,
The introduction pipe 28 provided with the metering orifice 27 in the lower chamber 26 may be inserted as far as the partition plate 25.

Note that it is more effective to arrange another auxiliary accumulator between the check valve 10 and the compressor 1, if necessary.

Next, the effect will be explained.

When the evaporator 4 is frosted during normal operation of the refrigeration cycle and the heat exchange efficiency of the evaporator 4 is reduced, a defrosting operation of the refrigeration cycle is performed to defrost the evaporator 4.

When the defrosting operation of the refrigeration cycle starts, the evaporator 4
A heater device (not shown) provided in the evaporator 4 is activated, the evaporator 4 is heated, and the frost on the evaporator 4 is melted.

At the same time, the refrigerant located inside the evaporator is warmed by this heater device, and this warmed refrigerant (liquid and gas) is led to the additional accumulator 22 and moves inside the additional accumulator 22 from bottom to top. The liquid refrigerant is separated into a liquid refrigerant and a gas refrigerant while the refrigerant is moving to the storage area, and the liquid refrigerant is stored in this additional accumulator 22, and the gas refrigerant passes through this additional accumulator 22 and is led to the accumulator 5, from where it passes through the suction pipe 21. , is returned to the compressor 1 via the check valve 20. At the end of this defrosting operation, the liquid refrigerant accumulates in the additional accumulator 22.
Therefore, the liquid refrigerant that overflows in the additional accumulator 22 at the start of the refrigeration cycle is led to the accumulator 5 through the piping and is stored in the accumulator 5, so that the liquid refrigerant backs up to the compressor 1. It does not deteriorate the reliability of the compressor.

In addition, when defrosting operation is performed immediately after starting the control, the gas refrigerant flowing back from the compressor 1 to the accumulator 5 is transferred to the 1 suction side pipe 2 of the compressor.
1 does not return to the accumulator 5 due to the check valve 20 provided in 1, so only a portion of the liquid refrigerant that returned from the evaporator 4 at the time of control startup remains in the accumulator 5. is accumulator 5
The liquid will not overflow and back into the compressor 1.

〔Effect of the invention〕

As described above, according to the present invention, a check valve is provided in the suction side pipe of the compressor, and the refrigerant pipe is arranged between the evaporator and the accumulator so that the refrigerant flows from the lower side to the upper side. Since an additional accumulator is provided, even when the compressor is started up after defrosting the heater, there is no liquid backlog of refrigerant in the compressor, and the reliability of the compressor is greatly improved.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the refrigeration cycle of the present invention, FIG. 2 is a sectional view of the additional accumulator, FIG. 3 is a diagram showing a modification of the additional accumulator, and FIG. 4 is an explanatory diagram showing the action of the additional accumulator. FIG. 5 is a diagram showing a conventional refrigeration cycle, and FIGS. 6 and 7 are diagrams showing an accumulator. 1... Compressor, 4... Evaporator, 5...
・Accumulator, 20... Check valve, 21... Suction side piping, 22... Additional accumulator.

Claims (1)

[Claims] In a refrigeration cycle in which a compressor, a condenser, an expansion device, an evaporator, and an accumulator are sequentially connected through refrigerant piping, a check valve is provided between the compressor and the accumulator, and the refrigerant is supplied between the evaporator and the accumulator in the refrigerant piping from the bottom to the top. A refrigeration cycle characterized in that an additional accumulator is arranged with an inlet on the lower side and an outlet on the upper side so as to allow water to flow.