JPH0638005B2 - Refrigeration equipment for automobiles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention provides a preliminary decompression device and a gas-phase refrigerant separator downstream of a condenser, and the gas-phase refrigerant separated here is a refrigerant compressor. The present invention relates to an automobile refrigeration system equipped with a so-called gas injection cycle in which the refrigeration capacity is improved by returning the refrigeration system to the refrigeration system.

[Prior Art] The basic structure of a conventional automobile refrigeration system is a compressor and a condenser for compressing and cooling a gas phase refrigerant to liquefy it, a receiver for storing the condenser, and a liquid phase refrigerant. It consists of an expansion valve for atomizing the appropriate amount of the atomized gas and sending it to the evaporator, and an evaporator for removing the latent heat of vaporization of the atomized liquid-phase refrigerant from the object to be cooled. Mainly depends on the performance of the compressor. Therefore, how to increase the amount of work taken out from the compressor with respect to the driving energy given to the compressor has been one of the important keys for improving the performance of the refrigeration system.

[Problems to be Solved by the Invention] In the refrigerating apparatus having the configuration described in the section of the related art, a novel configuration capable of efficiently performing the refrigerant compression work of the compressor by eliminating waste as much as possible. It is an object of the present invention to provide a refrigeration cycle for automobiles.

[Means for Solving Problems] An automobile refrigeration system of the present invention includes a swash plate type multi-cylinder compressor having a plurality of compression chambers, a refrigerant condenser, and a decompression device provided downstream of the refrigerant condenser. And a refrigerant gas-liquid separator, an expansion valve, a refrigerant evaporator, a refrigerant pipe that connects them, a part of the plurality of compression chambers of the compression chamber and the gas-liquid separator, the gas-liquid A gas-phase refrigerant flow path for returning the gas-phase refrigerant separated by a separator to the refrigerant compressor, wherein the remaining compression chambers of the plurality of compression chambers are connected to the evaporator by the refrigerant pipe. And

[Operation and Effect of the Invention] A refrigeration system for an automobile according to the present invention includes a swash plate type multi-cylinder compressor for compressing a gas-phase refrigerant, a condenser for liquefying a compressed gas-phase refrigerant,
A decompression device for vaporizing a part of the liquefied refrigerant, a gas-liquid separator for separating the vaporized refrigerant, an expansion valve for atomizing the liquid-phase refrigerant, and a refrigeration work by latent heat of vaporization of the atomized refrigerant. An evaporator and a refrigerating cycle configured by connecting the separated gas-phase refrigerant with gas injection means for returning to the compressor are provided,
Further, the swash plate type multi-cylinder compressor is provided with a plurality of cylinders, and some of the cylinders are exclusively used for compression of the gas-phase refrigerant generated by the pressure reducing device and separated by the gas-liquid separator. Since the remaining cylinder is designed to take in the suction and compression work of the refrigerant flowing out from the evaporator, not only the refrigerating capacity, which is the feature of the refrigeration system equipped with the gas injection cycle, but also the entire compressor is improved. It is possible to reduce the amount of compression work.

[Embodiment] The refrigerating apparatus of the present invention will be described below based on an embodiment shown in the accompanying drawings.

FIG. 1 is a cycle diagram of a refrigerating machine, in which 1 is a part of a plurality of vapor phase refrigerant compression cylinders incorporated in a compressor, and only one or a plurality of cylinders may be used. It may be an aggregate of individuals. Reference numeral 2 denotes the remaining cylinder of the plurality of cylinders, which may be only one or a plurality of aggregates. All of these cylinders may be incorporated in one compressor, or they may be dispersed and incorporated in a plurality of compressors. 3 is a condenser, 4 is a decompression device, and in this case, a capillary tube is used. Reference numeral 5 denotes a gas-liquid separator, inside of which a gas-liquid separator 6 having the shape illustrated in FIG. 5 is provided. Reference numeral 7 is a temperature-operated or capillary tube type expansion valve, 8 is an evaporator, and 9 is a gas-phase refrigerant passage (gas injection means for returning the gas-phase refrigerant in the gas-liquid separator 5 into the cylinder 1 ( Gas injection pipe).

FIG. 2 is a side sectional view of a swash plate type compressor having 10 cylinders used in the device of the present invention. 10 is a center housing, 11 and 12 are front and rear housings, and 13 is a central portion in the housing. Is a swash plate chamber, 20 is a swash plate, and 21 is a shaft for rotating the swash plate 20. 22 is a swash plate 20
Is a piston that moves back and forth in response to a movement that rotates obliquely with respect to the axial direction of the shaft 21, and five pistons are provided so as to surround the shaft 21. The peripheral edge of the swash plate 20 is located in a groove 22a provided in the piston 22, and a shoe for smoothly transmitting the movement of the swash plate 20 to the piston 22.
23 and a ball 24 are interposed between the two. 25 and 26
Are front and rear cylinder chambers formed by being surrounded by the front and rear end surfaces of the piston 22 and the cylinder wall surface 15 formed in the center housing 10.
There are 10 rooms in total.

On the cylinder wall surface 15 near the piston top dead center of the cylinder chambers 25 and 26, an intake valve 29 made of an elastic metal plate is provided.
The refrigerant suction ports 27 and 28 provided with are opened and are connected to suction ports 18 and 19 formed in the front and rear housings 11 and 12, respectively. The refrigerant suction port 27 is connected to the connection port 16 of the refrigerant pipe from the evaporator 8 assembled to the housing via the port 18, and the refrigerant suction port 28.
Is the connection port 17 of the gas injection pipe 9 via the port 19.
Is in communication with. The vapor-phase refrigerant compressed in each cylinder is discharged from a discharge port (not shown) through the discharge port 30. Reference numeral 50 is an oil pump for lubricating oil of the compressor, and 51 is an oil pan.

FIG. 3 is a schematic view of the configuration of an apparatus in which the refrigeration apparatus of the present invention is mounted on an automobile and used as an air conditioner, and 100 is a swash plate type compressor having 10 cylinders, The shaft is the pulley 40 for transmitting the torque of the engine.
It is fitted in 21. The condenser 3 is installed in the front part of the engine room where the outside air is exposed, and the evaporator 8 is installed in a duct for assembling the vehicle interior air conditioner provided under the instrument panel in front of the driver's seat. The expansion valve 7 may be a temperature-operated type or a constant pressure type expansion valve, or may be a capillary tube 7'as shown by a broken line in the figure. Reference numeral 41 is a pipe for connecting the discharge port 30 of the compressor 100 and the condenser 3, 42 is a pipe for supplying the liquid-phase refrigerant stored in the refrigerant gas-liquid separator 5 to the evaporator 8, and 43 is an evaporator 8 Is a pipe for returning the refrigerant that has been vaporized by passing through the compressor 100 to the compressor 100, and 44 is a frame body for mounting the evaporator 8. Other reference numerals in the figure are the same as those in FIG.

FIG. 5 is a sketch diagram illustrating the shape of the gas-liquid separation plate 6 that is attached to the upper space in the refrigerant gas-liquid separator 5 to more reliably separate the liquid-phase refrigerant and the gas-phase refrigerant, It is made of a corrosion-resistant metal plate, etc., and has a shape that forms a half part of a cone.

Next, the operation of the refrigerating apparatus shown in FIGS. 1 to 3 will be described with reference to FIG. 4 as a Mollier diagram of the refrigerating cycle. Under the state of point A on the Mollier diagram, it is sucked into some of the cylinders 2 of the plurality of cylinders incorporated in the compressor and is compressed to reach the state of point B.
Then, by passing through the condenser 3, the C state is reached,
At this time, the refrigerant pressure is the same as Ph when it is discharged from the compressor.
Is kept. Then, the refrigerant is depressurized to the D state by being passed through the capillary tube 4 serving as the depressurizing device, and is cooled with the vaporization of a part of the refrigerant, and the liquid phase refrigerant shifts to the state of the E point. . The refrigerant expanded by further passing through the expansion valve 7 reaches the inlet of the evaporator 8 under the state of F, and performs refrigerating work in the evaporator 8 to be in the state of point A at its outlet. Return.

On the other hand, the gas-phase refrigerant separated in the gas-liquid separator 5 passes through the injection pipe 9 at the point G and is shown in part of the cylinder of the compressor, 1 in FIG. 1 and FIG. In the compressor, it reaches the refrigerant inlet port 28 of the rear cylinder chamber 26, is compressed and reaches the H state, and the holding pressure is also increased to Ph which is the same level as the refrigerant discharged from the cylinder 2 or the front cylinder chamber 25. , Is combined with the refrigerant from the cylinder 2 and sent to the discharge port of the compressor.

FIG. 4 also shows a Mollier diagram drawn by an ordinary refrigerator without a gas injection cycle as a broken line. In this case, the refrigerant follows the state change of A → B → C → I → A.

An object of the present invention is to improve the refrigerating efficiency in the refrigerating cycle and the working efficiency of the compressor as mentioned at the beginning, and as a concrete measure thereof, the novel gas injection cycle as described above was created. In Although,
In order to theoretically prove that this new type refrigeration system has a higher refrigerating capacity than the conventional one, the respective characteristic value calculation formulas of both the old and new refrigeration systems are summarized in Table 1.

Based on the calculation formula shown in Table 1, the basic device configuration is common, the compressor has the same structure, and the refrigeration according to the present invention is different only in the presence or absence of a gas injection cycle. Using Freon-12 as the refrigerant, the device and the conventional device, the high-pressure side refrigerant pressure is 15 kg / cm ² · G, the low-pressure side refrigerant pressure is 2 kg / cm ² · G, and the compressor is 10 cylinders. For the above, when comparing the characteristic values under the operating condition setting that only one of the cylinders is used for compressing the refrigerant from the gas injection pipe,
The device of the present invention has a refrigerating capacity of 17% as compared with the conventional device,
It was also confirmed that the coefficient of performance as a value obtained by dividing the value of the refrigerating capacity by the value of the work of the compressor, that is, the operating efficiency of the compressor, could be improved by almost 17% as well.

A supplementary explanation of the mechanism for improving the operation efficiency of the compressor is that the vapor-phase refrigerant generated in the decompression device 4 performs cooling work as a refrigerant, that is, latent heat of vaporization when changing from a liquid phase to a vapor phase from the outside. Have no ability to do the work of absorbing,
It is possible to avoid the irrationality of increasing the volume of the gas-phase refrigerant while it is being passed through the expansion valve 7 and to compress the gas-liquid separator 5 in a state where the specific weight at the stage of separation is larger. By returning to the compressor, the amount of gas-phase refrigerant flowing back to the compressor can be reduced. Therefore, the refrigerant suction capacity of the compressor is loosened, and the effect of enlarging the compressor is finally obtained.

Further, in the device of the present invention, since the gas-liquid separator having the gas-liquid separation plate having the shape as shown in FIG. 3 is provided upstream of the expansion valve, the dryness of the refrigerant at the inlet of the evaporator is increased. Is small and the specific weight is small, the pressure loss of the refrigerant in the evaporator can be kept sufficiently low, and the cooling capacity can be improved also from this aspect.

In the above embodiment, the gas-phase refrigerant compression cylinder 1 discharged from the gas-liquid separator 5 and the gas-phase refrigerant compression cylinder 2 flowing out from the evaporator 8 are provided with 10 cylinders. It was prepared by using each cylinder of the swash plate type compressor 100 separately, but as another method, the cylinder 1 and the cylinder 2 may be cylinders incorporated in independent compressors, or a plurality of cylinders may be installed. The volume ratio of the cylinder 1 and the cylinder 2 as an aggregate of individual cylinders or as a single cylinder may be arbitrarily determined as necessary. Further, when two or more compressors are used in combination, the structure of the compressor may be of a rotary type such as a vane type in addition to the type of reciprocating cylinders.

INDUSTRIAL APPLICABILITY The device of the present invention has a high operation efficiency of the compressor, and the compressor can be made compact by that amount, and the power cost can be reduced. It is particularly suitable as

[Brief description of drawings]

FIG. 1 is a refrigeration cycle diagram of the refrigeration system of the present invention, FIG. 2 is a side sectional view of a 10-cylinder swash plate compressor used in the system, and FIG. 3 is an air conditioner for mounting on an automobile. FIG. 4 is a schematic diagram of the device of the present invention, FIG. 4 is a Mollier diagram relating to this device, and FIG. 5 is an explanatory view of the shape of the gas-liquid separation plate. In the figure, 1 ... part of the cylinder of the compressor, 2 ... remaining cylinder of the compressor, 3 ... condenser, 4 ... pressure reducing device,
5 ... Refrigerant gas-liquid separator, 7 ... Expansion valve, 8 ... Evaporator,
9 ... Gas-phase refrigerant flow path (gas injection pipe), 16 ...
… Port of refrigerant suction pipe from the evaporator, 17 …… Port of refrigerant suction pipe from gas injection, 25, 26 …… Cylinder chamber

Claims (1)

[Claims] 1. A swash plate type multi-cylinder compressor having a plurality of compression chambers, a refrigerant condenser, a decompression device and a refrigerant gas-liquid separator provided downstream of the refrigerant condenser, an expansion valve, and a refrigerant evaporator. A vessel,
Refrigerant pipes connecting these, a part of the plurality of compression chambers and the gas-liquid separator are connected to each other, and the gas-phase refrigerant separated by the gas-liquid separator is returned to the refrigerant compressor. A refrigeration system for an automobile, comprising a gas-phase refrigerant flow path, wherein the remaining compression chambers of the plurality of compression chambers are connected to the evaporator by the refrigerant pipe.