JPH03129209A - Air conditioner - Google Patents

Abstract

PURPOSE:To enable a high discharging pressure to be attained from a second compressing part at a temperature lower than a limit temperature of a compressor and further to enable a high reliable and more efficient operation to be carried out by a method wherein a first compressing part at a lower stage and a second compressing part at a higher stage are stored within a case and then a cylinder volume of the first compressing part at the lower stage is larger than a cylinder volume of the second compressing part at the higher stage. CONSTITUTION:A two-cylinder compressor having a cylinder volume of a first compressing part 2 at a lower stage larger than a cylinder volume of a second compressing part 3 at a higher stage is provided. Saturated liquid got from a lower part of an accumulator 4 passes through a low pressure reducing mechanism 20, the liquid is evaporated and gasified by an outdoor heat exchanger 21 and again the gasified liquid is sucked again into the low stage second compressing part 2. In this case, a cylinder volume of the low stage first compressing part 2 is larger than a cylinder volume of the high stage second compressing part 3 and it always absorbs the saturated gas within an accumulator 4. With such an arrangement, it is possible to increase a discharging pressure without exceeding a limit temperature of the compressor while a discharged gas temperature at the higher stage is hardly increased and then an efficient and high reliable operation can be carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an air conditioner, and more particularly to a two-stage compressed air conditioner using a compressor having one electric motor and two compression chambers.

[Conventional technology]

FIG. 5 is a diagram showing a conventional refrigeration cycle shown in, for example, Japanese Utility Model Application Publication No. 63-172867.
The compressor is composed of a first compression section 2 on the lower stage side and a second compression section 3 on the higher stage side.

5 is the condenser, 7 is the receiver, 10.11 is the aperture for Nakasho,
6 forms a refrigeration cycle connected sequentially by evaporators.

Next, the operation will be explained. The low-pressure gas refrigerant that has exited the evaporator 6 passes through the accumulator 4 and is sucked into the first compression section 2 on the lower stage side, and the gas refrigerant compressed to intermediate pressure is
The refrigerant is sucked into the second compression section 3 on the higher stage side via the pipe 9, becomes a high-pressure and high-temperature gas refrigerant, and is sent to the heat exchanger 5. The high-pressure liquid is reduced to an intermediate pressure by the throttle 10 and separated into a gas phase and a liquid phase by the receiver 7. The gas phase part is sucked into the second compression part 3 on the high stage side again through the pipe 8, and the liquid phase part is reduced in pressure by the second throttle mechanism 11 to a low pressure, gasified in the evaporator 6, and passed through the accumulator 4 to the low stage part. It was configured to be sucked into the first compression section 2 on the side.

(Problem to be Solved by the Invention) Since the conventional refrigeration cycle is configured as described above, the refrigerant sucked into the high-stage compressor is superheated to some extent, so the high-stage compressor There was a drawback that the discharge temperature of the compressor became high and could exceed the limit temperature of the compressor.

Therefore, in order to prevent the discharge temperature from becoming high even when the discharge pressure is increased, the compressor is equipped with a cylinder volume of the first compression section on the low stage side that is larger than the cylinder volume of the second compression section on the high stage side. However, there was a problem that the effect could not be fully demonstrated.

This invention was made in order to solve the above-mentioned problems, and the refrigerant sucked into the high-stage compressor is brought to the temperature of saturated gas in the palm of the hand, so that it can be compressed without being overheated. By installing a compressor in the tower in which the cylinder volume of the first compression section on the low stage side is larger than the cylinder volume of the second compression section on the high stage side, even if the discharge pressure is increased, the limit temperature of the compressor may not be exceeded. The purpose of the present invention is to provide an air conditioner that is highly reliable and capable of increasing the discharge pressure.

(Means for Solving the Problems) The air conditioner according to the present invention includes a first air conditioner on the lower side in the case.
It is equipped with a compressor that houses a compression section and a second compression section on the high stage side, and the cylinder volume of the first compression section on the low stage side is larger than the cylinder volume of the second compression section on the high stage side. be.

[For production]

In the air conditioner according to the present invention, by providing a high intermediate pressure in the first compression section on the low stage side, this compressed gas refrigerant is sucked into the second compression section on the high stage side, and the compressed gas refrigerant is drawn into the second compression section on the high stage side. It works so that high discharge pressure can be obtained from the second compression section without exceeding the compressor limit temperature.

(Example) Hereinafter, an air conditioner according to an example of the present invention will be described based on the drawings. In Figures 1 and 2, 1 is a compressor with a first compression section 2 on the lower stage side having a cylinder volume that is a larger discharge volume, and a cylinder volume smaller than the first compression section 2 on the lower stage side. A second compression section 3 on the higher stage side is provided, and both compression sections 2 and 3 are coaxially connected and driven by an electric motor section 15. Reference numeral 16 denotes a low-stage discharge pipe through which refrigerant is led out of the compressor 1 from the first compression section 2 on the low-stage side, and is connected to the accumulator 4.
be led to.

Reference numeral 17 denotes a high-stage discharge pipe, so that the refrigerant compressed to high pressure in the compressor 1 is led out of the compressor 1 from the second compression section 3 on the high-stage side through the discharge pipe 17. It has become. 18 is a solenoid valve, 4 is an accumulator, 19.2
0 is a throttle mechanism for pressure reduction, which is a medium pressure vacuum throttle mechanism and a low pressure vacuum throttle mechanism, respectively. 21 is an outdoor heat exchanger, 22
23 is an indoor heat exchanger, 23 is a four-way valve, 24 is a check valve, 25 is a high-stage suction pipe of the second compression section 3, and 26 is a low-stage suction pipe of the first compression section 2.

FIG. 3 is a Molière diagram of one embodiment of the present invention.

In Figures 2 and 3, azh indicates the operating point on the refrigeration cycle, a is the low stage suction point, b is the low stage discharge point, C is the low stage intermediate pressure liquid point, and d is the low stage side Indicates the two-phase point in the side evaporator section, where e is the suction point on the high-stage side, f is the discharge point on the high-stage side, g is the liquid phase point at the outlet of the condenser on the high-stage side, and h is the two-phase point after the throttle on the high-stage side. It is a pressure point.

With the above configuration, by increasing the compression ratio in the low-stage refrigeration cycle, it is possible to move from point a to point b.
The compressed gas refrigerant enters the accumulator 4, and the saturated liquid from the lower part of the accumulator 4 passes through the low pressure reducing throttle mechanism 20, evaporates into gas in the outdoor heat exchanger 21, and returns to the lower stage side. It is sucked into the first compression section 2.

On the other hand, in the high-stage refrigeration cycle, the accumulator 4
The saturated gas is sucked in at the high-stage suction point e in the chamber, compressed to the high-stage discharge point f, and then transferred to the indoor heat exchanger 22.
The refrigerant is condensed and liquefied at the liquid phase point g at the outlet of the high-pressure side condenser, and the pressure is reduced by the medium-pressure reducing throttle mechanism 19, and the two-phase refrigerant is introduced into the accumulator 4 at the two-phase medium-pressure point h after the high-pressure side throttle. It will be destroyed.

According to one embodiment of the present invention, a two-cylinder compressor is provided in which the cylinder volume of the first compression section 2 on the low stage side is larger than the cylinder volume of the second compression section 3 on the high stage side, and the lower part of the accumulator 4 is The saturated liquid is evaporated and gasified in the outdoor heat exchanger 21 via the low pressure reducing throttle mechanism 20 and sucked into the first compression section 2 on the low stage side again, and the cylinder volume of the first compression chamber 2 on the low stage side is reduced. is larger than the cylinder volume of the second compression chamber 3 on the high stage side and always sucks the saturated gas in the accumulator 4. It becomes possible to increase the discharge pressure without causing the discharge gas temperature on the side to rise easily and to exceed the pressure m machine limit temperature, thereby enabling efficient and reliable operation.

FIG. 4 is an explanatory diagram showing a comparison of the behavior of the refrigeration cycle on the Molière diagram of this embodiment and the conventional example.

27 is an equimixture line of the compressor limit temperature where a point corresponding to the high-stage discharge point f is located.

The behavior of the refrigeration cycle on the sony luminum diagram of the two-stage compression refrigeration cycle equipped with the compressor according to an embodiment of the present invention (
According to this embodiment, by focusing on the higher-stage discharge point f regarding the behavior on the Molière a diagram (shown by the dotted line) of the conventional two-stage compression refrigeration cycle (shown by the solid line) and the conventional two-stage compression refrigeration cycle,
It can be seen that a higher discharge pressure than the conventional example can be obtained from the second compression section on the high stage side without exceeding the limit temperature of the compressor.

According to the air conditioner of one embodiment of the present invention, the discharge pipe 16 of the first compression section 2 on the lower stage side is connected to the accumulator 4, and the flow is carried out from the lower part of the accumulator 4 via the liquid pipe through the throttle mechanism 20. , outdoor heat exchanger 21 and the first compression section 2
The low stage refrigeration cycle leading to the suction pipe 25 and the discharge pipe 17 of the second compression section 3 on the high stage are connected via the four-way valve 23 to the indoor heat exchanger 22 and the medium pressure reducing throttle mechanism 19, It is connected to the accumulator 4 and passes from the gas section of the accumulator 4 through the high-stage suction pipe 26 to the second high-stage side.
A two-stage compression air conditioner having a high-stage refrigeration cycle leading to a compression section 3, in which a first compression section 2 on a low-stage side and a second compression section 3 on a high-stage side are housed in a case la, By using an air conditioner equipped with a compressor 1 in which the cylinder volume of the first compression section 2 on the low-pressure side is larger than the cylinder volume of the second compression section 3 on the high-pressure side, in the refrigeration cycle, the cylinder volume of the first compression section 2 on the low-pressure side The cylinder volume of the first compression section 2 is
Since a 2-cylinder compressor with a cylinder capacity larger than This has the effect of providing a harmonizing device.

Further, it is preferable that the rotation speed of the compressor can be changed.

〔Effect of the invention〕

As described above, the air conditioner of the present invention has two compression sections in which the cylinder volume of the first compression section on the low stage side is larger than the cylinder volume of the second compression section on the high stage side. By installing a cylinder compressor, it is possible to obtain high discharge pressure from the second compression section on the high stage side without exceeding the limit temperature of the compressor, resulting in highly reliable and efficient operation. This effect is achieved.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the main parts of an air conditioner according to an embodiment of the present invention, Fig. 2 is a diagram showing a two-stage compression refrigeration cycle equipped with the same compressor, and Fig. 3 is a diagram showing the main parts of an air conditioner according to an embodiment of the present invention. A diagram showing the behavior of a refrigeration cycle, FIG. 4 is an explanatory diagram showing a comparison of the behavior of a refrigeration cycle on a Molière diagram of an embodiment of the present invention and a conventional example, and FIG. 5 is a diagram showing a refrigeration cycle of a conventional example. It is. 1... Compressor 1a... Case 2... First compressor 3 on the low pressure side... Second compressor 4 on the high pressure side... ...Accumulator 4a...Gas section 16...Low pressure side discharge pipe 7...High pressure side discharge pipe 9...Medium pressure reduction throttle mechanism 0... ...Low pressure reducing pressure throttling mechanism 1...Outdoor heat exchanger 2...Indoor heat exchanger 3...Four-way valve 5...Lower side suction piping 6...High stage side suction piping 8...Liquid piping

Claims (1)

[Claims] The discharge piping of the first compression section on the low stage side is connected to the accumulator, and from the bottom of the accumulator, via the liquid piping and the throttling mechanism, it reaches the outdoor heat exchanger and the suction piping on the low stage side of the first compression section. The discharge pipes of the low stage refrigeration cycle and the second compression section on the high stage side are connected to the accumulator via a four-way valve, an indoor heat exchanger and a throttling mechanism, and the gas section of the accumulator is connected to the high stage side. An air conditioner having a high-stage refrigeration cycle leading to a second compression section on the high-stage side via suction piping, the case including a first compression section on the low-stage side and a second compression section on the high-stage side. An air conditioner equipped with a compressor that accommodates a compressor and has a cylinder volume of a first compression section on a low stage side larger than a cylinder volume of a second compression section on a high stage side.