JPH1194368A - Freezing cycle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a freezing cycle device which is so arranged as to suppress the frequency drop caused by the pressure pulsation of a compressor by adding a little structural change while utilizing, as it is, the basic structure of a freezing cycle device being so arranged as to perform gas injection. SOLUTION: A freezing cycle device 1, where a check valve 11 and an opening and closing valve 10 are interposed, in order toward the side of a gas-liquid separator, in a gas injection pipe 9, is equipped with a bypass pipe 15 which connects a gas injection pipe 9 between the opening and closing valve 10 and the check valve 11 with the suction port 4a of the compressor 4 or the low- pressure pipe on suction side, and a bypass valve 16 which is interposed in the bypass pipe 15 and breaks the bypass pipe 15 by closing the bypass pipe 15 when the opening and closing valve 10 is in open condition and opens the bypass pipe 15 by opening it when the opening and closing valve 10 is in closed condition.

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 a gas-liquid separator and injecting a gas component separated by the gas-liquid separator into a compressor in accordance with an operation state. .

[0002]

2. Description of the Related Art As a refrigeration cycle apparatus, Japanese Utility Model No. 1-1
As disclosed in Japanese Patent No. 34857, a gas-liquid separator is added to the components of the refrigeration cycle, and the gas component separated by the gas-liquid separator is injected into a compressor, and the gas for guiding the gas component is introduced. It has been proposed to interpose an electromagnetic on-off valve and a check valve in an injection pipe. According to this, in a state where the on-off valve is closed and the operation is switched to the normal operation from the high output operation by the gas injection, the pressure on the compressor side becomes higher than the pressure on the gas-liquid separator side by stopping the operation of the compressor. Even in such a case, there is an advantage that the check valve can prevent the backflow of the refrigerant gas from the compressor to the on-off valve, thereby preventing chattering of the on-off valve.

[0003]

The refrigeration cycle apparatus generally has a problem of compression loss due to pressure pulsation of the compressor. In particular, the pressure pulsation of the compressor decreases as the compression ratio decreases at a low load. Therefore, there is a problem that compression loss occurs due to the pressure pulsation and efficiency is reduced.

The present invention has been made in view of such a problem, and an object of the present invention is to make a slight structural change while using the basic structure of a refrigeration cycle apparatus for performing gas injection as it is. It is another object of the present invention to provide a refrigeration cycle device that suppresses a decrease in efficiency due to pressure pulsation of the compressor by adding the pressure.

[0005]

According to a first aspect of the present invention, there is provided a refrigeration cycle apparatus according to the present invention, wherein a discharge port and a suction port of a compressor are arranged in order from a discharge port of the compressor to a suction port. The compressor is connected via a first pressure reducing mechanism, a gas-liquid separator, a second pressure reducing mechanism, and an evaporator, and the compressor is provided with an injection port separately and independently of the suction port. A gas-liquid separator is connected via a gas injection pipe, and the gas injection pipe is provided with a check valve and an open / close valve in order from the compressor side to the gas-liquid separator side. In the refrigeration cycle device, a bypass pipe communicating between the gas injection pipe between the on-off valve and the check valve and a low-pressure gas pipe on a suction port or a suction side of the compressor is interposed in the bypass pipe. Closed when the closing valve is open and shut off the bypass pipe, the on-off valve is characterized in that it comprises a bypass valve for opening said bypass pipe is opened when in the closed state.

According to a second aspect of the present invention, there is provided a refrigeration cycle apparatus according to the first aspect, wherein the on-off valve is controlled to open and close according to a load state of the refrigeration cycle apparatus. I do. In the refrigeration cycle device according to the third aspect of the present invention, the discharge port and the suction port of the compressor are:
In order from the discharge port of the compressor to the suction port, a condenser,
The compressor is connected via a first pressure reducing mechanism, a gas-liquid separator, a second pressure reducing mechanism, and an evaporator, and the compressor is provided with an injection port separately and independently of the suction port. A gas-liquid separator is connected via a gas injection pipe, and in the refrigeration cycle apparatus, in which a check valve is interposed in the gas injection pipe, the gas-liquid separator is connected between the gas-liquid separator and the check valve. A bypass pipe for communicating the gas injection pipe with a low-pressure gas pipe on a suction port or a suction port side of the compressor, and a bypass pipe provided at a connection position between the bypass pipe and the gas passage, wherein the gas injection pipe and the bypass pipe are provided. And a three-way valve for selectively opening and closing the two. According to a fourth aspect of the present invention, there is provided a refrigeration cycle apparatus according to the third aspect, wherein the three-way valve is switch-controlled in accordance with a load state of the refrigeration cycle apparatus. A refrigeration cycle apparatus according to a fifth aspect of the present invention is the refrigeration cycle apparatus according to any one of the first to fourth aspects, wherein the check valve is built in the compressor.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS According to a first embodiment of the present invention, a refrigeration cycle apparatus for performing gas injection includes:
Simply adding a bypass pipe and connecting this bypass pipe to the compressor inlet and gas injection pipe will induce the pressure pulsation of the compressor, which tends to increase especially at low load, to the bypass pipe and Can be attenuated. Therefore, a gas injection pipe, a check valve, and an on-off valve required for performing gas injection are utilized even in a normal operation state in which the gas injection is not performed to reduce compression loss due to pressure pulsation of the compressor. Therefore, it is possible to suppress a decrease in efficiency due to pressure pulsation at a relatively low cost. According to the second embodiment of the present invention, the bypass valve for controlling the opening and closing of the bypass pipe includes:
Since the control is performed in accordance with the load state of the refrigeration cycle device, it is reasonable to deal with the pressure pulsation of the compressor, which tends to be a problem particularly at a low load.

According to the third embodiment of the present invention, a three-way valve having the functions of the on-off valve and the bypass valve is installed at the connection position between the bypass pipe and the gas injection pipe for gas injection. Therefore, the size of the apparatus can be reduced, the responsiveness of control can be improved, and the running cost can be reduced. According to the fourth embodiment of the present invention, the switching of the three-way valve is controlled in accordance with the load state of the refrigeration cycle apparatus. It is reasonable. Further, according to the fifth embodiment of the present invention, since the check valve is built in the compressor, the dead volume from the compressor to the check valve can be reduced, and the pressure can be further reduced. Pulsation loss can be reduced, and a decrease in compressor efficiency can be suppressed.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall system diagram of the refrigeration cycle device in the first embodiment. This refrigeration cycle apparatus 1 includes a condenser 2, an evaporator 3, a compressor 4, and a decompression mechanism 5, which are basic components of the refrigeration cycle.
The compressor 4 is interposed in the pipe 6 on one side and the pressure reducing mechanism 5 is interposed in the pipe 7 on the other side to form one refrigerant circulation path as a whole.

The pressure reducing mechanism 5 included in the refrigeration cycle apparatus 1
Is composed of a first pressure reducing mechanism 5a and a second pressure reducing mechanism 5b. The first pressure reducing mechanism 5a plays a role of expanding the high-pressure condensate flowing out of the condenser 2 to an intermediate pressure,
The second pressure reducing mechanism 5b plays a role of expanding the condensate at the intermediate pressure to a predetermined lower pressure state. A gas-liquid separator 8 for separating the refrigerant gas expanded by the first pressure reducing mechanism 5a into a liquid component and a gas portion is disposed between the first and second pressure reducing mechanisms 5a and 5b. The liquid component of the refrigerant gas separated by the liquid separator 8 is supplied to the second pressure reducing mechanism 5.

The compressor 4 has an injection port 4c independent of the suction port 4a and the discharge port 4b.
The above-described gas-liquid separator 8 is communicated with the compressor 4 through a gas passage formed by a gas injection pipe 9 and an injection port 4c, and compresses a gas portion of the saturated gas separated by the gas-liquid separator 8. Machine 4 can be introduced. Gas injection pipe 9
, An electromagnetic on-off valve 10 and a check valve 11 are interposed. For example, when a large capacity is required during the heating operation, the on-off valve 10 is opened and gas injection is performed on the compressor 4. Thereby, the refrigeration cycle apparatus 1 is set to a high-output operation in which the capacity of the compressor 4 is improved.

The on-off valve 10 is opened and closed by a controller (not shown) according to a control signal corresponding to the air conditioning load. For example, when the air conditioning load is small, the on-off valve 10 is closed. Conversely, when the air conditioning load is large, for example, when a large capacity is required during the heating operation, the on-off valve 10 is opened. Parameters that determine the air conditioning load or operating conditions include frequency, compression ratio, indoor and outdoor temperature, indoor and outdoor air flow,
It includes a cooling operation request, a heating operation request, and the like. Check valve 11
Prohibits the flow of the injection gas in a direction opposite to the flow direction. For example, when the pressure of the compressor 4 becomes higher than the pressure of the gas-liquid separator 8 immediately after the operation of the compressor 4 is stopped. Further, the flow of the refrigerant gas from the compressor 4 to the on-off valve 10 is restricted. The check valve 11 may be installed independently of the gas injection pipe 9, but is preferably installed so as to be built in the compressor 4. When the check valve 11 is built in the compressor 4, the dead volume from the compressor 4 to the check valve 11 can be reduced, and the pressure pulsation loss can be reduced, so that the efficiency can be improved. Can be.

The refrigeration cycle apparatus 1 includes a gas injection pipe 9 and a low pressure gas pipe 6 on the suction port 4 a side of the compressor 4.
, And a bypass valve 16 formed of an electromagnetic on-off valve is interposed in the bypass pipe 15. That is, one end of the bypass pipe 15 has a gas injection pipe 9 between the check valve 11 and the on-off valve 10.
The other end of the bypass pipe 15 is connected to the pipe 6 of the suction port 4 a of the compressor 4. The bypass valve 16 is closed when the above-described injection gas on-off valve 10 is in an open state, and is opened when the injection on-off valve 10 is in a closed state.

During normal operation, the gas injection on-off valve 10 is closed and the bypass valve 16 is closed.
Is opened. Thereby, the pressure pulsation of the compressor 4 which tends to increase as the load becomes lower can be induced to the suction port 4a side of the compressor 4 through the bypass pipe 15 and attenuated, so that the check valve 11 can be reduced. This reduces chattering and compression loss, and improves compressor efficiency.

FIG. 2 is an overall system diagram of a refrigeration cycle apparatus according to a second embodiment. In the description of the second embodiment, the same components as those in the above-described first embodiment are denoted by the same reference numerals, and description thereof will be omitted. In the refrigeration cycle apparatus 20 of the second embodiment, a three-way valve 21 is used instead of the on-off valve 10 and the bypass valve 16 employed in the first embodiment.
And a gas injection pipe 9. The three-way valve 21 selectively switches between communication of the gas injection pipe 9 to the compressor 4 and communication of the bypass pipe 15.

In the refrigeration cycle apparatus 20 according to the second embodiment, the two elements of the on-off valve 10 and the bypass valve 16 employed in the first embodiment are integrated into one element called a three-way valve 17. Not only can the device be made compact while maintaining the same functions and functions as in the first embodiment, the responsiveness of control can be improved, and the running cost can be reduced.

[0017]

According to the present invention, it is possible to suppress a decrease in efficiency due to the pressure pulsation of the compressor by making a slight structural change while using the basic structure of the refrigeration cycle apparatus for performing gas injection as it is. .

[Brief description of the drawings]

FIG. 1 is an overall system diagram of a refrigeration cycle device according to a first embodiment of the present invention.

FIG. 2 is an overall system diagram of a refrigeration cycle device according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigeration cycle apparatus 2 Condenser 3 Evaporator 4 Compressor 4a Suction port 4b Discharge port 4c Injection port 8 Gas-liquid separator 9 Gas injection pipe 10 Opening / closing valve 11 Check valve 15 Bypass pipe 16 Bypass valve 17 Three-way valve

Continued on the front page (72) Inventor Shinji Watanabe 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Hideo Hirano 1006 Oji Kadoma Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Invention Person Koji Murosono 1006 Kadoma, Kazuma, Kadoma, Osaka Pref., Matsushita Electric Industrial Co., Ltd. (72) Inventor Shigeru Shigeru 1006, Kadoma, Kadoma, Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. 1006 Oaza Kadoma Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] 1. A condenser, a first pressure reducing mechanism, a gas-liquid separator, a second pressure reducing mechanism, and an evaporator, wherein a discharge port and a suction port of a compressor are arranged in this order from a discharge port of the compressor to a suction port. In addition, the compressor is provided with an injection port separately and independently from the suction port, and the injection port and the gas-liquid separator are connected via a gas injection pipe, In a refrigeration cycle device in which a gas injection pipe is provided with a check valve and an on-off valve in order from the compressor side to the gas-liquid separator side, a gas between the on-off valve and the check valve is provided. A bypass pipe that communicates the gas injection pipe with a low-pressure gas pipe on the suction side or the suction side of the compressor; and a bypass pipe that is interposed in the bypass pipe and closes when the on-off valve is in an open state to close the bypass pipe. Cut off And a bypass valve for opening the bypass pipe by opening when the on-off valve is in a closed state. 2. The refrigeration cycle apparatus according to claim 1, wherein the on-off valve is controlled to open and close according to a load state of the refrigeration cycle apparatus. 3. A condenser, a first decompression mechanism, a gas-liquid separator, a second decompression mechanism, and an evaporator, wherein the discharge port and the suction port of the compressor are arranged in this order from the discharge port of the compressor to the suction port. In addition, the compressor is provided with an injection port separately and independently from the suction port, and the injection port and the gas-liquid separator are connected via a gas injection pipe, In a refrigeration cycle device in which a check valve is interposed in a gas injection pipe, the gas injection pipe between the gas-liquid separator and the check valve and a low pressure on a suction port or a suction port side of the compressor. A bypass pipe that communicates with a gas pipe; and a three-way valve that is provided at a connection position between the bypass pipe and the gas passage and selectively opens and closes the gas injection pipe and the bypass pipe. A refrigeration cycle device. 4. The refrigeration cycle apparatus according to claim 3, wherein the three-way valve is switch-controlled in accordance with a load state of the refrigeration cycle apparatus. 5. The refrigeration cycle apparatus according to claim 1, wherein the check valve is built in the compressor.