JPH0518613A - Device of refri gerating cycle - Google Patents

Abstract

PURPOSE:To secure sufficiently a room cooling operation and space heating capability by providing a plurality of pouring-in ports that are connected to one of the compression chambers of a compressor from the piping of an economizer. CONSTITUTION:During the room cooling operation the heat exchanger 4 on the side of use is used as an evaporator and the heat exhchanger 8 on the side of no using as a condenser by switching a four-way valve 3. When the diameter of the coolant pour-in port that is most suitable for rated operation is used in low speed operation, the gas coolant that is poured in from a gas separator 6 is excessive in comparison with the case of rated operation so that diameters 13a, 13c of the pour-in diameter that are small are used. Solenoids 11a, 11b are, therefore, open and solenoids 11b, 11c are closed. During the rated operation diameters of coolant pour-in, 13b, 13d are used which are suitable for this operation. Therefore, solenoid valves 11a, 11c are closed and 11b, 11d are open. In the case of high speed operation, the volume of the coolant that is poured in is short as compared with the case of rated drive so that two large and small pour-in ports are used simultaneously. Therefore, the solenoid valve 11 is fully open.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration cycle apparatus having an injection compressor driven by an inverter and having high efficiency.

[0002]

2. Description of the Related Art FIG. 6 shows, for example, Japanese Unexamined Patent Publication No. 62-23364.
It is an air conditioner using the conventional gas injection type refrigeration cycle with an economizer, which is disclosed in Japanese Patent No. 5 publication, and includes a non-use side heat exchanger (outdoor heat exchanger) 8, a compressor 1, a use side heat exchanger. (Indoor heat exchanger) 4, first pressure reducer 5, gas-liquid separator 6 for separating the refrigerant into a gas phase and a liquid phase, and a second pressure reducer 7 are connected in this order to form a refrigerant circuit, An economizer pipe 10 that connects the gas phase portion of the gas-liquid separator 6 and the intermediate pressure region of the compressor 1 is provided. The length of this pipe 10 is the Mollier diagram showing that the cooling and heating capacity increases and the coefficient of performance increases. This is a refrigeration cycle device that is set to a value that is larger than the determined value. FIG. 7 shows a configuration diagram of a refrigerant circuit provided with a scroll gas injection compressor. The scroll compressor 1 has compression chambers 1a and 1b of the same shape, and the economizer pipe 10a,
Refrigerant inlet 13 for each compression chamber 1a, 1b from 10b
a and 13b are provided.

Next, the operation will be described. First, the operation during heating operation will be described. The high-temperature and high-pressure gas refrigerant compressed by the compressor 1 is guided from the discharge pipe 2 through the four-way valve 3 to the utilization side heat exchanger 4, where the gas refrigerant is condensed and liquefied. That is, the utilization side heat exchanger 4 becomes a condenser. At this time, the heat of condensation is released from the heat exchanger 4 on the utilization side to perform the heating operation. After that, the liquid refrigerant passes through the first pressure reducer 5, becomes a low-temperature medium-pressure gas-liquid two-phase gas refrigerant, and is guided to the gas-liquid separator 6. Here, only the liquid phase of the refrigerant separated into the gas phase and the liquid phase passes through the second pressure reducer 7,
The low-temperature low-pressure gas-liquid two-phase refrigerant is guided to the non-use side heat exchanger 8, where the gas-liquid two-phase gas refrigerant receives heat from the outside air to evaporate and gasify. That is, the non-use side heat exchanger 8 becomes an evaporator. Then, it is guided to the suction port of the compressor 1 through the accumulator 9. Further, the gas refrigerant in the gas-liquid separator is injected through the economizer pipe 10 until the pressure in the compression chamber of the compressor 1 reaches the gas-liquid separator pressure.
Therefore, the circulation amount of the refrigerant discharged from the compressor 1 is larger than the circulation amount of the refrigerant sucked into the compressor 1 by the amount of the gas refrigerant injected from the gas-liquid separator.

Next, the operation during the cooling operation will be described. In this case, by switching the four-way valve 3, the use side heat exchanger 4 is used as an evaporator and the non-use side heat exchanger 8 is used as a condenser. Since the subsequent operation is the same as the operation during the heating operation, the description is omitted here.

Japanese Utility Model Laid-Open No. 63-150096 is an air conditioner using a multi-cylinder compressor, and each compression chamber of the multi-cylinder compressor is provided with a gas injection port. Further, a solenoid valve is provided at the gas injection port of each compression chamber to control the capacity by opening and closing the solenoid valve.

Further, Japanese Patent Laid-Open No. 55-20370 discloses an air conditioner using a multi-cylinder compressor, in which each compression chamber of the multi-cylinder compressor is provided with a liquid injection port. Further, a solenoid valve is provided at the suction port of each compression chamber and the liquid injection port of each compression chamber to control the capacity by opening and closing the solenoid valve.

Japanese Laid-Open Patent Publication No. 55-14935 discloses a rotary compressor provided with two injection ports, which uses a first port for gas injection and a second port for liquid injection.

Further, Japanese Patent Application Laid-Open No. 59-147955 discloses 2
One injection port is provided, and a circuit for gas injection from each gas-liquid separator to the compressor is provided.

[0009]

Since the conventional refrigeration cycle apparatus is constructed as described above, when the compressor 1 is operated at a low speed when used as an inverter-driven refrigeration cycle apparatus, the gas-liquid separator 6 is used. The amount of the refrigerant injected into the compression chamber of the compressor 1 through the economizer pipe 10 becomes excessive and a backflow occurs to the gas-liquid separator 6. In addition, the amount of injected refrigerant is insufficient during high-speed operation. Even if an attempt is made to increase the injection port diameter in order to cope with this shortage of the injected refrigerant amount, it has been impossible due to structural restrictions. For these reasons, there was a problem that heating and cooling capacity could not be obtained sufficiently and the coefficient of performance decreased.

In Japanese Utility Model Laid-Open No. 63-150096, since each compression chamber has only one port for gas injection, it is used as an inverter-driven compressor as in Japanese Patent Laid-Open No. 62-233645. Then,
Due to changes in operating speed, it was not possible to inject the optimum amount of refrigerant, and sufficient heating / cooling capacity could not be obtained.
Moreover, there was a problem that the coefficient of performance decreased.

Further, in Japanese Patent Laid-Open No. 55-20370, the capacity control is performed by switching the operation of a plurality of rotary cylinder compressors and with or without injection, so that only a stepwise capacity change can be performed. There was a problem that the comfortable comfort could not be obtained.

In Japanese Patent Laid-Open No. 59-147955, only one port for liquid injection is provided in each compression chamber. Therefore, when the air-conditioning load changes and the condensing pressure / evaporating pressure fluctuates due to changes in indoor / outdoor temperature, etc., the liquid injection amount changes. At this time, if the injection is insufficient, the cooling / heating capacity decreases,
If the injection becomes excessive, there is a problem that the compressor is in a liquid compression operation state, the compressor stops, and there is a risk of damage to the compressor.

Further, JP-A-55-14935 discloses that
Gas injection is performed to increase the capacity, and liquid injection is performed to cool the discharge temperature.
Therefore, since the capacity increase and the efficiency increase by the injection are performed by one injection port, if the compressor is driven by an inverter and the speed is changed, the operation speed changes in accordance with the change of the operation speed as in JP-A-62-233645. There was a problem that the optimum amount of refrigerant could not be injected, sufficient heating / cooling capacity could not be obtained, and the coefficient of performance decreased. Further, when the low speed operation is performed, the amount of the liquid refrigerant injected from the liquid injection port is increased, and there is a risk of performing the liquid compression operation, and there is a problem of lack of reliability.

Further, Japanese Patent Laid-Open Publication No. 55-14935 is limited to the rotary compressor, but when liquid and gas injection is performed, the injection time is long because the injection time is structurally long. It needs to be large. Therefore, the ineffective volume in the compression chamber increases, and the efficiency deteriorates. Therefore,
Higher injection effect can be obtained by using a scroll compressor that can take a long injection time.

Further, in Japanese Patent Laid-Open No. 59-147955, a plurality of gas-liquid separators are provided and gas refrigerants having different pressures are injected into a compressor. Therefore, when this is driven by an inverter-driven compressor, At low speed operation, the pressure difference between the condensation pressure (high pressure) and the evaporation pressure (low pressure) becomes small,
Since the pressures between the gas-liquid separators are almost equal, the effect is almost the same as when only one gas-liquid separator is provided. Further, since the flow rate control mechanism of the injection refrigerant is not provided, the reverse flow of the refrigerant occurs due to the excess of the injection refrigerant during the low speed operation. Further, during high-speed operation, there is a problem that sufficient heating and cooling capacity cannot be obtained due to the shortage of injection refrigerant, and the increase in efficiency is also small.

An object of the present invention is to provide a refrigeration cycle device having a high coefficient of performance, which can ensure sufficient cooling operation and heating capacity during low speed operation and high speed operation in an inverter driven gas injection type refrigeration cycle device. .

[0017]

[Means for Solving the Problems] Claim 1 according to the present invention
The refrigeration cycle device includes a compressor, a condenser, a first pressure reducer,
A gas-liquid separator (economizer), a second decompressor, and a refrigeration cycle in which an evaporator is connected in this order, and an economizer pipe connecting the gas phase part of the gas-liquid separator and the intermediate pressure region of the compressor. The refrigeration cycle apparatus further comprises a plurality of inlets connected from the economizer pipe to one compression chamber of the compressor.

A refrigeration cycle apparatus according to a second aspect of the present invention is the refrigeration cycle apparatus according to the first aspect, wherein a plurality of inlets connected to one compression chamber of the compressor have different diameters.

[0019]

In the refrigeration cycle apparatus according to the first aspect of the present invention, the plurality of inlets makes it possible to inject a large amount of refrigerant with a large injection cross-sectional area into the compression chamber.

In the refrigeration cycle apparatus according to the second aspect of the present invention, the number of inlets can be reduced by making the diameters of the plurality of inlets different.

[0021]

【Example】

Example 1. FIG. 1 is a schematic diagram of a refrigeration cycle apparatus using a gas injection type refrigeration cycle with an economizer, in which a non-use side heat exchanger 8, a compressor 1, a use side heat exchanger 4, a first pressure reducer 5 and a refrigerant are vaporized. A gas-liquid separator 6 for separating into a liquid phase and a liquid phase, and a refrigerant circuit configured by connecting a second pressure reducer 7 in this order, an intermediate pressure region of the gas phase portion of the gas-liquid separator 6 and the compressor. An economizer pipe 10 for connection is provided. FIG. 2 shows a configuration diagram of a refrigerant circuit provided with a scroll gas injection compressor. The scroll compressor has two compression chambers, and two refrigerant inlets 1 with different inlet diameters for each compression chamber from the economizer pipe.
3, a check valve 12 and a solenoid valve 11 are provided in the middle. Further, the diameters of the refrigerant inlets 13a and 13c are 13b.
And smaller than 13d.

Next, the operation during the heating operation will be described.
The high-temperature and high-pressure gas refrigerant compressed by the compressor 1 is discharged through the discharge pipe 2
Through the four-way valve 3 to the utilization side heat exchanger 4, where the gas refrigerant is condensed and liquefied. That is, the utilization side heat exchanger 4 becomes a condenser. At this time, the heat of condensation is released from the heat exchanger 4 on the utilization side to perform the heating operation. After that, the liquid refrigerant passes through the first pressure reducer 5, becomes a low-temperature medium-pressure gas-liquid two-phase gas refrigerant, and is guided to the gas-liquid separator 6. Here, only the liquid phase of the refrigerant separated into the gas phase and the liquid phase passes through the second pressure reducer 7, and the low-temperature low-pressure gas-liquid two-phase refrigerant is guided to the non-use side heat exchanger 8. Here, the gas-liquid two-phase gas refrigerant receives heat from the outside air and evaporates to be gasified. That is, the non-use side heat exchanger 8 becomes an evaporator.
Then, it is guided to the compressor 1 through the accumulator 9.
Further, the gas refrigerant in the gas-liquid separator 6 is injected through the economizer pipe 10 until the pressure in the compression chamber of the compressor 1 reaches the gas-liquid separator pressure. Therefore, the circulation amount of the refrigerant discharged from the compressor 1 is larger than the circulation amount of the refrigerant sucked into the compressor 1 by the amount of the gas refrigerant injected from the gas-liquid separator 6.

Next, the operation during the cooling operation will be described. In this case, by switching the four-way valve 3, the use side heat exchanger 4 is used as an evaporator and the non-use side heat exchanger 8 is used as a condenser. Since the subsequent operation is the same as the operation during the heating operation, the description is omitted here.

When the optimum diameter of the refrigerant injection port for the rated operation is used in the low speed operation, the gas refrigerant injected from the gas-liquid separator 6 becomes excessive in comparison with the rated operation in the above description of the operation operation. In case of small injection port 13a,
Use 13c. Therefore, the solenoid valves 11a and 11d are opened,
11b and 11c are in a closed state. During the rated operation, the refrigerant injection port diameters 13b and 13d suitable for this operation are used. Therefore, the solenoid valves 11a, 11c are closed, 11b, 11d
Is open. In the case of high-speed operation, the amount of injected refrigerant is insufficient as compared with the case of rated operation, so control is performed to use two large and small injection ports at the same time. Therefore, the solenoid valve 11 is all open.

The relationship between the refrigerant inlet diameter and the intermediate pressure (pressure inside the gas-liquid separator) is shown in FIG.

Example 2. In Example 1, the amount of gas refrigerant from the gas-liquid separator was controlled by the inlets having different inlet diameters for each operating frequency. However, even if a plurality of inlets having the same diameter are provided and controlled. , The number of injection ports is increased, but other similar effects can be obtained.

Example 3. In the first embodiment, the check valve for preventing the reverse flow of the refrigerant in the compression chamber is provided between the gas-liquid separator and the solenoid valve for controlling the amount of injected refrigerant, but the ineffective volume in the compression chamber is reduced. It may be provided just before the inlet. Figure 1
An example of a refrigeration cycle device using a scroll compressor is shown in Fig.

Although a plurality of injection ports have been described in the present embodiment, the same effect as in the above embodiment can be obtained with three or four injection ports, for example.

[0029]

The present invention has the following effects.
The refrigeration cycle apparatus according to claim 1 includes a compressor, a condenser, and a first
A refrigeration cycle in which a pressure reducer, a gas-liquid separator (economizer), a second pressure reducer, and an evaporator are connected in this order, and an economizer pipe connecting the gas phase part of the gas-liquid separator and the intermediate pressure region of the compressor. In a refrigeration cycle device equipped with
Since the structure is provided with a plurality of inlets connected from the economizer pipe to one compression chamber of the compressor, the refrigerant injection amount can be increased without being restricted by the structure of the compressor.

The refrigeration cycle apparatus of claim 2 is the same as that of claim 1.
In the refrigeration cycle apparatus, since the plurality of inlets connected to one compression chamber of the compressor have different diameters, the number of inlets can be reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a refrigeration cycle apparatus according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram when a scroll compressor of the refrigeration cycle device according to the first embodiment of the present invention is used.

FIG. 3 is a diagram showing a relationship between a refrigerant inlet diameter and an intermediate pressure of the refrigeration cycle device according to Embodiment 1 of the present invention.

FIG. 4 is a Mollier diagram of the refrigeration cycle apparatus according to Embodiment 1 of the present invention.

FIG. 5 is a configuration diagram of a refrigeration cycle apparatus according to Embodiment 3 of the present invention.

FIG. 6 is a configuration diagram of a conventional refrigeration cycle apparatus.

FIG. 7 is a configuration diagram when a scroll compressor of a conventional refrigeration cycle device is used.

[Explanation of symbols]

1 compressor 4 User side heat exchanger 5 First decompressor 6 gas-liquid separator 7 Second decompressor 8 Non-use side heat exchanger 10 Economizer piping 13a, 13b inlet

Claims (2)

[Claims] 1. A refrigeration cycle in which a compressor, a condenser, a first pressure reducer, a gas-liquid separator (economizer), a second pressure reducer, and an evaporator are connected in this order, and a gas phase part of the gas-liquid separator. In a refrigeration cycle apparatus comprising: and an economizer pipe connecting the intermediate pressure region of the compressor, a plurality of inlets connected from the economizer pipe to one compression chamber of the compressor are provided. Refrigeration cycle device. 2. A refrigeration cycle apparatus, wherein a plurality of inlets connected to one compression chamber of the compressor have different diameters.