JPH01277175A - Refrigerating cycle - Google Patents

Abstract

PURPOSE:To make it possible to extract saturated steam on the way to the heat exchange of a refrigerant vaporizer without lowering its efficiency, by heat-exchanging a refrigerant extracted on the way to the heat exchange of said refrigerant vaporizer with the refrigerant on a high pressure side. CONSTITUTION:The refrigerant which is subjected to excess cooling passing through a refrigerant heat exchanger 9 is introduced into a pressure reducing device 5 where it is subjected to insulation expansion, turned into low pressure and atomized saturated liquid, then flow into a refrigerant vaporizer 6. The saturated liquid which has flown into the refrigerant vaporizer 6 passes through the refrigerant vaporizer 6, removes the latent heat from the air blowing in a compartment, and turns into saturated steam. When the saturated liquid turns into saturated steam by about half inside the refrigerant vaporizer 6, the saturated steam is extracted outside the refrigerant vaporizer 6 and a vapor-liquid separator 8 installed on the way to the heat exchange of the refrigerant vaporizer 6, which removes the saturated steam on the downstream of the vapor-liquid separator 8 and produces saturated liquid. As a result, the refrigerant vaporizer 6 on the downstream of the vapor-liquid separator 8 makes it possible to improve the efficiency of heat exchange with the air blowing into the compartment and hence vaporize the saturated liquid in a short length of a refrigerant passage in the refrigerant vaporizer 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a refrigeration cycle used in a cooling device or a refrigeration device.

[Prior Art] Conventionally, as a means for improving the heat exchange capacity of a refrigerant evaporator in a refrigeration cycle, a method is known that extracts gas refrigerant that evaporates during heat exchange in the refrigerant evaporator. This technology extracts the gas refrigerant that evaporated during heat exchange in the refrigerant evaporator, so that the refrigerant evaporator can be filled with only unevaporated refrigerant from the middle of heat exchange. The heat exchange efficiency between the passing fluid (for example, indoor air) and the refrigerant is improved, and the refrigerant evaporator can be made smaller or its capacity can be increased if the size is the same.

On the other hand, as a means for extracting the gas refrigerant evaporated during heat exchange in the refrigerant evaporator, a gas-liquid separator is used, which has a structure in which a double pipe section is provided in the refrigerant passage during heat exchange in the refrigerant evaporator. . This takes advantage of the property that the evaporated and gasified gas refrigerant flows through the center of the refrigerant passage, and the unevaporated refrigerant flows along the inner peripheral surface of the refrigerant pipe. Refrigerant was extracted from the refrigerant evaporator and returned to the refrigerant compressor.

[Problems to be Solved by the Invention] The unevaporated refrigerant (hereinafter referred to as saturated liquid) that has flowed into the refrigerant evaporator absorbs latent heat from the fluid passing through the refrigerant evaporator and evaporates to form a gas (refrigerant (hereinafter referred to as saturated liquid)). It then becomes superheated steam by absorbing latent heat from the fluid passing through the refrigerant evaporator.

However, in the conventional system, saturated vapor capable of absorbing latent heat from the fluid passing through the refrigerant evaporator is returned to the refrigerant compressor, so the efficiency of the refrigeration cycle is reduced.

In addition, with the above-mentioned gas-liquid separator, it is difficult to completely separate saturated liquid and saturated vapor and extract only saturated vapor from the refrigerant evaporator, so in a refrigeration cycle equipped with a receiver, the refrigerant compressor Saturated liquid refrigerant was introduced into the tank, potentially damaging the refrigerant compressor.

The present invention has been made in view of the above circumstances, and its purpose is to provide a refrigeration cycle in which efficiency does not decrease even if saturated steam is extracted during heat exchange in a refrigerant evaporator.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a refrigerant compressor that compresses and discharges a refrigerant, and a method for heat exchange between the high-pressure refrigerant discharged by the refrigerant compressor and a first fluid. A refrigerant condenser that liquefies and condenses the refrigerant, a pressure reducing device W that adiabatically expands the liquefied refrigerant in the refrigerant condenser, and a second
A refrigerant evaporator that exchanges heat with a second fluid to remove latent heat from the second fluid and evaporates it, and a refrigerant evaporator that is installed in the middle of the heat exchange of the refrigerant evaporator and that exchanges unevaporated refrigerant before evaporation and gaseous refrigerant that has evaporated and gasified. A refrigerant heat exchanger that exchanges heat between a gas-liquid separator that separates and extracts a gas refrigerant, and a refrigerant that flows between the refrigerant compressor and the pressure reduction device, and the gas-phase refrigerant decomposed by the gas-liquid separator. The technical means is to have an exchanger.

[Function] The present invention having the above configuration extracts saturated vapor, which is a gas refrigerant, from the middle of heat exchange in a refrigerant evaporator using a gas-liquid separator. The saturated vapor extracted from the refrigerant evaporator is guided to the refrigerant heat exchanger, where it exchanges heat with the high-pressure refrigerant flowing between the refrigerant compressor and the pressure reduction device. The saturated vapor extracted from the refrigerant evaporator has a lower temperature than the refrigerant on the high-pressure side, so it absorbs heat from the refrigerant on the high-pressure side, evaporates, becomes superheated steam, and is guided to the refrigerant compressor.

On the other hand, when the refrigerant on the high-pressure side passes through the refrigerant heat exchanger, it is cooled by losing heat to the saturated vapor separated by the gas-liquid separator.

[Effects of the Invention] According to the present invention, the refrigerant extracted from the middle of heat exchange of the refrigerant evaporator and the refrigerant on the high pressure side are exchanged with the refrigerant extracted from the middle of heat exchange by the refrigerant heat exchanger. The refrigerant completely evaporates and becomes superheated vapor, and the refrigerant on the high pressure side is cooled, so that the second fluid passing through the refrigerant evaporator can be efficiently cooled.

[Example] Next, the refrigeration cycle of the present invention will be explained based on an example shown in the drawing.

FIG. 1 shows a refrigerant circuit diagram of a refrigeration cycle 1.

The refrigeration cycle 1 of this embodiment is used in an air conditioner for an automobile, and includes a refrigerant compressor 2, a refrigerant condenser 3, a receiver 4, a pressure reducing device 5 such as a sapling valve, a refrigerant evaporator 6, and a refrigerant evaporator 6. In addition to the well-known configuration consisting of a refrigerant pipe 7 connected to the refrigerant evaporator 6, there is also a gas-liquid separator 8 that extracts saturated vapor (gasified refrigerant) from the middle of heat exchange in the refrigerant evaporator 6, and a saturated vapor extracted by the gas-liquid separator 8. It consists of a refrigerant heat exchanger 9 that exchanges heat with the refrigerant flowing between the refrigerant condenser 3 and the pressure reducing device 5.

The gas-liquid separator 8 is installed in the refrigerant passage of the refrigerant evaporator 6 during heat exchange, and converts the refrigerant flowing during the heat exchange into a saturated liquid (
Separated into unevaporated refrigerant) and saturated vapor (gasified refrigerant),
It extracts saturated steam. The structure of this gas-liquid separator 8 is, as shown in FIG. two entrances 12 and 2
It has two outlets 13.14. The inlet 12 is an opening at one end of the outer circumferential tube 10 and is connected to the lower end of the upstream side of the refrigerant evaporator 6 divided into two. Further, the outlet 13 is opened at the other end of the inner circumferential tube 11, with one end at the center of the outer circumferential tube 10 and toward the flow direction of the refrigerant.

Further, the outlet 14 is connected to the upper end of the downstream side of the refrigerant evaporator 6 which is divided into two parts, and allows the refrigerant between the outer peripheral tube 10 and the inner peripheral tube 11 to be returned to the refrigerant evaporator 6. It is something to return. The other end of the outer circumferential tube 10 is caulked to the outer circumference of the inner circumferential tube 11 to prevent the refrigerant from leaking between the outer circumferential tube 10 and the inner circumferential tube 11.

The gas-liquid separator 8 is installed at a position where 30 to 70% of the saturated liquid supplied to the refrigerant evaporator 6 is converted into saturated vapor, preferably about 40 to 60% of the saturated vapor. It is installed in a position to extract.

The refrigerant heat exchanger 9 exchanges heat with the saturated vapor extracted from the outlet 13 of the gas-liquid separator 8 and the high-pressure refrigerant flowing from the refrigerant condenser 3 to the pressure reducing device 5, for example, from the receiver 4 to the pressure reducing device 5. The flowing refrigerant flows into the inner tube,
It consists of a double-tube type heat exchanger in which saturated steam extracted from the gas-liquid separator 8 flows through a tube around the tube.

Next, the operation of the above embodiment will be explained.

When the refrigerant compressor 2 operates under the power of the engine,
Compresses refrigerant and discharges high temperature, high pressure refrigerant. This high-temperature, high-pressure refrigerant is led to the refrigerant a2 condenser 3, where it exchanges heat with the air outside the vehicle interior (the first fluid of the present invention), and is liquefied and condensed. The liquefied refrigerant is guided to the receiver 4,
Only liquid refrigerant is discharged. The liquid refrigerant discharged from the receiver 4 is guided to a refrigerant heat exchanger 9, and then a gas-liquid separator 8
Heat is exchanged with the extracted saturated steam.

At this time, the temperature of the refrigerant flowing from the receiver 4 to the pressure reducing device 5 is higher than the saturated vapor extracted by the gas-liquid separator 38. Therefore, the refrigerant flowing from the receiver 4 to the pressure reducing device 5 is The saturated steam extracted from 8 removes latent heat and is further cooled. As a result, as shown by the solid line A in FIG. 3, the enthalpy of the refrigerant on the inlet side of the pressure reducing device 5 is lower than that of the conventional refrigeration cycle without the refrigerant heat exchanger 9, as shown by the broken line B.

The refrigerant that has passed through the refrigerant heat exchanger 9 and has been supercooled is led to the pressure reducing device 5 where it is adiabatically expanded, turned into a low temperature, low pressure mist-like saturated liquid, and flows into the refrigerant evaporator 6.

The saturated liquid that has flowed into the refrigerant evaporator 6 absorbs latent heat from the air (second fluid of the present invention) that passes through the refrigerant evaporator 6 and is blown into the vehicle interior, evaporates, and becomes saturated vapor. Refrigerant evaporator 6
When about half of the saturated liquid becomes saturated vapor, the gas-liquid separator 8 installed in the middle of the heat exchange of the refrigerant evaporator 6
Saturated vapor is extracted outside the refrigerant evaporator 6. As a result, the downstream part of the gas-liquid fraction 8 is made into a saturated liquid by removing saturated vapor. As a result, the refrigerant evaporator 6 downstream of the gas-liquid separator 8 has improved heat exchange efficiency with the air blown into the vehicle interior, and the refrigerant path length in the refrigerant evaporator 6 is short.
The saturated liquid can be evaporated.

In other words, by providing the gas-liquid separator 8, the heat exchange efficiency of the refrigerant evaporator 6 downstream of the gas-liquid separator 8 is improved. The container 6 can be made smaller. In addition, the refrigerant evaporator 6
If the size of the refrigerant evaporator is the same as that without the gas-liquid separator 8, the heat exchange capacity of the refrigerant evaporator can be increased. On the other hand, the air blown into the vehicle interior is sent to the refrigerant evaporator 6.
As the air passes through the air, latent heat is removed and cooled, and the air is blown out into the vehicle interior, cooling the interior of the vehicle.

The low-temperature, low-pressure saturated vapor extracted by the gas-liquid separator 8 is guided to the refrigerant heat exchanger 9, where it exchanges heat with the refrigerant flowing from the receiver 4 to the pressure reducing device 5. In this refrigerant refrigerant heat exchanger 9, as described above, the saturated vapor extracted from the gas-liquid separator 8 absorbs latent heat from the refrigerant flowing from the receiver 4 to the pressure reducing device 5 and evaporates, turning the saturated vapor into superheated vapor.

Then, the refrigerant converted into superheated vapor in the refrigerant heat exchanger 9 passes through the refrigerant evaporator 6, joins with the refrigerant converted into superheated vapor, and is sucked into the refrigerant compressor 2 again, and the above cycle is repeated.

As shown in this embodiment, from the refrigerant evaporator G to the gas-liquid separator 8
Since the refrigerant flowing from the receiver 4 to the pressure reducing device 5 is cooled by the saturated steam extracted by the refrigerant, the cooling efficiency in the vehicle interior can be improved.

In addition, as shown in this embodiment, in the case of the refrigeration cycle 1 using the receiver 4, even when the saturated liquid is extracted from the gas-liquid separator 8 while being contained in saturated vapor, the refrigerant refrigerant heat exchanger 9 Since the liquid refrigerant is completely gasified by
can be protected from damage due to liquid compression.

(Modified Example) Although the refrigerant heat exchanger 9 of the above embodiment is a double-tube type heat exchanger, there is a spiral around the refrigerant pipe 7 that guides the refrigerant from the receiver 4 to the pressure reducing device 'It, 5. Other structures may be used, such as a structure in which the refrigerant pipe is wound in a spiral shape and the saturated vapor extracted from the gas-liquid separator 8 flows through the refrigerant pipe wound in a spiral shape.

Further, although an example in which the refrigerant refrigerant heat exchanger 9 is provided between the receiver 4 and the pressure reducing device 5 has been shown, the refrigerant refrigerant heat exchanger 9 may be installed between the refrigerant condenser 3 and the receiver 4, or between the refrigerant compressor 2. It may also be provided between the refrigerant condenser 3 and the refrigerant condenser 3.

Furthermore, although an example was shown in which the refrigeration cycle of the present invention is applied to an air Jl phase device for automobiles, air conditioning devices for home, commercial, and industrial use, as well as air conditioning devices, refrigerators, and refrigeration devices for railways, ships, etc., have been shown. It may be applied to etc.

[Brief explanation of the drawing]

Figure 1 is the refrigerant circuit diagram of the refrigeration cycle, Figure 2 is the gas-liquid component 1
3 is a Mollier diagram of the refrigeration cycle shown in FIG. 1.

Claims (1)

[Claims] 1) (a) A refrigerant compressor that compresses and discharges refrigerant;
b) a refrigerant condenser that liquefies and condenses the high-pressure refrigerant discharged by the refrigerant compressor by exchanging heat with a first fluid; (c) a pressure reducing device that adiabatically expands the liquefied refrigerant of the refrigerant condenser; d) a refrigerant evaporator that exchanges heat with a second fluid to remove latent heat from the second fluid and evaporates the refrigerant adiabatically expanded by the pressure reducing device; (e) provided in the middle of the heat exchange of the refrigerant evaporator; (f) a gas-liquid separator that separates unevaporated refrigerant before evaporation and gasified gas refrigerant and extracts the gas refrigerant; A refrigeration cycle comprising a refrigerant heat exchanger that exchanges heat with a refrigerant flowing between a compressor and the pressure reducing device.