JP2001074321A - Supercritical vapor compressing cycle device and pressure control valve with release valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To operate a supercritical vapor compressing cycle device along the optimum control line upon a normal time and permit coping with a condition that a high driving force is necessitated in a case when an inner pressure of a diaphragm chamber is raised by a high outdoor air temperature when a cooling load is reduced. SOLUTION: In a supercritical vapor compressing cycle device, in which a refrigerant, such as carbon dioxide gas or the like, is circulated through a compressor 1, a radiator 2 and an evaporator 3 sequentially to effect operation in a supercritical area, a high-pressure control valve 7, controlling a pressure in the outlet port side of the radiator 2 by controlling the degree of communication with the radiator 2 and the evaporator 3 while sensing the pressure and temperature of the outlet port side of the radiator 2, and a release valve 8, opened when a pressure difference between the outlet port side pressure of the radiator 2 and the inlet port side pressure of the evaporator 3 is higher than a predetermined value, are provided in parallel to each other on the way of a refrigerant passage 5 from the radiator 2 to the evaporator 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a supercritical vapor compression cycle device and a pressure control valve with a relief valve.

2. Description of the Related Art In recent years, in order to prevent ozone layer depletion,
Research has been conducted using carbon dioxide (CO ₂ ) instead of chlorofluorocarbon as a refrigerant. In a refrigeration cycle device using carbon dioxide gas refrigerant, unlike the one using fluorocarbon refrigerant,
Such a refrigeration cycle is called a supercritical vapor compression cycle because the operation is performed in a supercritical region with a low critical temperature, and the condensation coefficient does not occur on the high pressure side, and the coefficient of performance (operating coefficient) depends on the situation. In addition, it has the characteristic that pressure fluctuations are more likely to occur as compared with those using a chlorofluorocarbon refrigerant.

In the above-described supercritical vapor compression cycle apparatus, as disclosed in Japanese Patent Application Laid-Open No. 9-264622, the balance between the internal pressure of the diaphragm chamber filled with the refrigerant and the refrigerant pressure at the outlet of the radiator is disclosed. An operating pressure control valve is provided in the middle of the refrigerant passage from the radiator to the evaporator, and the pressure control valve controls the pressure and temperature of the refrigerant at the outlet side of the radiator along the optimal control line. Kaihei 10-97
As disclosed in Japanese Patent Publication No. 19, a pressure-reducing valve responsive to the pressure of the refrigerant at the inlet of the evaporator is moved from the radiator so that the pressure difference between the pressure of the refrigerant at the inlet of the evaporator and the refrigerant becomes a predetermined value. There is known one provided in the middle of a refrigerant passage leading to an evaporator.

[0003]

Problems to be Solved by the Invention
As disclosed in Japanese Patent Application Publication No. 2 (1999) -2005, in the one controlled optimally by a pressure control valve which operates based on an equilibrium relationship between the internal pressure of the diaphragm chamber filled with the refrigerant and the refrigerant pressure on the radiator outlet side,
Although control on the high pressure side is possible, this control is determined by the refrigerant pressure on the radiator outlet side regardless of the size of the cooling load, so it cannot cope with the need for high driving force when the cooling load is small. . In addition, in the vehicle air conditioner, when the air conditioner is stopped at a high outside temperature, the diaphragm chamber pressure becomes high, even if started in this state,
If the pressure does not exceed the outside air temperature equivalent pressure, the valve will not open, the air conditioner cannot be operated, and the pressure on the high pressure side may be exceeded.

As disclosed in Japanese Patent Application Laid-Open No. 10-9719, the pressure of the refrigerant on the inlet side of the evaporator is adjusted so that the pressure difference between the refrigerant and the inlet side of the evaporator becomes a predetermined value. In the case where the pressure reducing valve is provided in the middle of the refrigerant passage from the radiator to the evaporator, the problem does not occur as described above,
The pressure and temperature of the refrigerant on the outlet side of the radiator are not controlled so as to be along the optimal control line, so that the operation is performed with a low coefficient of performance and the economic efficiency of the refrigeration cycle device is inevitably reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The present invention operates normally along an optimal control line, and requires a high driving force when the cooling load is small. Provided is a supercritical vapor compression cycle device and a pressure control valve with a relief valve that can cope with an increase in the diaphragm chamber pressure due to a high outside temperature and can perform an efficient operation while ensuring safety on a high pressure side. It is intended to be.

[0006]

In order to achieve the above object, a supercritical vapor compression cycle device according to the first aspect of the present invention comprises a compressor, a radiator, and an evaporator in which a refrigerant such as carbon dioxide is used. In a supercritical vapor compression cycle device that circulates sequentially and is operated in a supercritical region, the supercritical vapor compression cycle device is provided in the middle of a refrigerant passage from the radiator to the evaporator, and is sensitive to the pressure and temperature of the refrigerant at the outlet side of the radiator. A high-pressure control valve that controls the degree of communication between the radiator and the evaporator to control the pressure at the radiator outlet side, and the high-pressure control valve in the middle of a refrigerant passage from the radiator to the evaporator. A relief valve that is provided in parallel and that opens when the pressure difference between the pressure of the refrigerant on the outlet side of the radiator and the pressure of the refrigerant on the inlet side of the evaporator is equal to or higher than a predetermined value. .

In order to achieve the above-mentioned object, a supercritical vapor compression cycle device according to the second aspect of the present invention provides a compressor, a radiator, and an evaporator in which a refrigerant such as carbon dioxide gas circulates sequentially. In a supercritical vapor compression cycle device operated in a supercritical region, a pressure that is provided in the middle of a refrigerant passage from the radiator to the evaporator and is sensitive to the pressure and temperature of the refrigerant flowing from the radiator to the evaporator. A high-pressure control valve that is driven by the temperature sensing means to control the connection / disconnection and the degree of communication between the radiator and the evaporator, and controls the pressure at the radiator outlet side; and from the radiator to the evaporator. It is provided in parallel with the high-pressure control valve in the middle of the refrigerant passage, and opens when the pressure difference between the pressure of the refrigerant on the outlet side of the radiator and the pressure of the refrigerant on the inlet side of the evaporator is a predetermined value or more, The pressure / temperature sensitive means Those having a relief valve to be exposed in the flow of the refrigerant toward the evaporator from the radiator.

According to another aspect of the present invention, there is provided a pressure control valve with a relief valve according to a third aspect of the present invention, comprising a valve housing having a pressure control valve port and a relief valve port in a parallel relationship. A pressure / temperature responsive means provided in the valve housing and responsive to pressure and temperature; and a pressure control valve element driven by the pressure / temperature responsive means for opening / closing a valve port for a pressure control valve and setting an opening degree. And a relief valve element for opening and closing the relief valve valve port, and a relief pressure setting spring for urging the relief valve element in the valve closing direction.

According to a fourth aspect of the present invention, in the pressure control valve with a relief valve, the pressure / temperature sensitive means is disposed in a pressure / temperature sensitive chamber formed upstream of the relief valve port. When the valve element opens, the pressure
The flow of the fluid is generated in the temperature sensitive chamber, and the pressure / temperature sensitive means is exposed to the flow of the fluid.

According to a fifth aspect of the present invention, in the pressure control valve with a relief valve, the pressure / temperature sensitive means is a sealed bellows device.

A pressure control valve with a relief valve according to a sixth aspect of the present invention is a supercritical vapor compression system in which a refrigerant such as carbon dioxide gas circulates sequentially through a compressor, a radiator, and an evaporator to operate in a supercritical region. In the cycle device, the refrigerant flow is provided in the middle of the refrigerant passage from the radiator to the evaporator, and controls the flow rate of the refrigerant flowing from the radiator to the evaporator in response to the pressure and temperature of the refrigerant on the outlet side of the radiator. And a relief valve that opens when the pressure difference between the pressure of the refrigerant at the outlet of the radiator and the pressure of the refrigerant at the inlet of the evaporator is equal to or higher than a predetermined value. Things.

In the supercritical vapor compression cycle device according to the first aspect of the present invention, the high pressure control valve controls the degree of communication between the radiator and the evaporator in response to the pressure and temperature of the refrigerant at the outlet of the radiator. The pressure at the outlet side of the radiator is controlled by this control.By this control, the operation along the optimal control line is normally performed, and the differential pressure between the pressure of the refrigerant at the outlet side of the radiator and the pressure of the refrigerant at the inlet side of the evaporator is obtained. When the pressure exceeds the predetermined value, the relief valve is opened to guarantee the operation of the supercritical vapor compression cycle device that can save power when the cooling load is small.

[0013] In the supercritical vapor compression cycle device according to the second aspect of the present invention, the high-pressure control valve communicates with the radiator and the evaporator in response to the pressure and temperature of the refrigerant at the outlet side of the radiator and shuts off and communicates. By controlling the pressure, the pressure at the outlet side of the radiator is controlled.By this control, the operation along the optimal control line is performed at normal times, and the pressure of the refrigerant at the outlet side of the radiator and the pressure of the refrigerant at the inlet side of the evaporator are controlled. When the differential pressure is equal to or higher than a predetermined value, the relief valve opens to ensure the operation of the supercritical vapor compression cycle device corresponding to the need for high driving force when the cooling load is small, If the relief valve opens,
Even when the high pressure control valve is closed, a fluid flow occurs in the pressure / temperature sensitive chamber, and the pressure / temperature sensitive means is exposed to the flow of the refrigerant from the radiator to the evaporator, and the pressure / temperature sensitive means is Becomes sensitive to regular temperature.

In the pressure control valve with a relief valve according to the third aspect of the present invention, the pressure control valve body is driven by the pressure / temperature sensitive means to open and close the valve port for the pressure control valve and to set the opening degree. When the differential pressure across the valve port exceeds the relief pressure set by the relief pressure setting spring, the relief valve body opens and the pressure control valve valve port communicates in a bypass configuration.

In the pressure control valve with a relief valve according to the fourth aspect of the present invention, when the relief valve is opened, a flow of fluid is generated in the pressure / temperature sensitive chamber even if the high pressure control valve is closed. The temperature sensitive means is exposed to the flow of the fluid in the pressure / temperature sensitive chamber, and the pressure / temperature sensitive means becomes sensitive to the pressure and temperature of the fluid flowing in the pressure / temperature sensitive chamber;

In the pressure control valve with a relief valve according to the fifth aspect of the present invention, the pressure control valve body is driven by a sealed bellows device which is a pressure / temperature sensitive means to open and close the valve port for the pressure control valve. Set the degree.

According to a pressure control valve with a relief valve according to the invention of claim 6, in the supercritical vapor compression cycle device,
A high-pressure control valve that controls the flow rate of the refrigerant flowing from the radiator to the evaporator in response to the pressure and temperature of the refrigerant at the outlet of the radiator, and the pressure of the refrigerant at the outlet of the radiator and the refrigerant at the inlet of the evaporator. It is used as a combined valve with a relief valve that opens when the pressure difference from the pressure is greater than or equal to a predetermined value.

[0018]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a supercritical vapor compression cycle device according to the present invention. In this supercritical vapor compression cycle, a compressor 1, a radiator (gas cooler) 2, and an evaporator 3 are connected in a closed loop manner by refrigerant passages (pipes) 4, 5, and 6, and the closed loop is formed by carbon dioxide gas or the like. Refrigerant circulates.

In the middle of the refrigerant passage 5 from the radiator 2 to the evaporator 3, the communication between the radiator 2 and the evaporator 3 is controlled in response to the pressure and temperature of the refrigerant at the outlet side of the radiator 2. A high-pressure control valve 7 for quantitatively controlling the temperature and controlling the pressure on the outlet side of the radiator, and a differential pressure between the pressure of the refrigerant on the outlet side of the radiator 2 and the pressure of the refrigerant on the inlet side of the evaporator 3 is predetermined. A relief valve 8 that opens when the value is equal to or larger than the value is provided in parallel with each other.

The high-pressure control valve 7 and the relief valve 8 can be formed as one composite valve by a pressure control valve 10 with a relief valve as shown in FIG. Next, the pressure control valve 10 with a relief valve will be described. The pressure control valve 10 with a relief valve is loaded in a valve receiving hole 12 formed in the main body 11 of the radiator 2 or the evaporator 3. An end member 14 screwed to the valve housing 13 is attached to the valve housing 13 of the pressure control valve 10 with a relief valve.
, An inlet port 15 communicating with the outlet side of the radiator 2, a passage 16 in the housing directly communicating with the inlet port 15, and a spring retainer member 17 screwed to the valve housing 13. An outlet port 18 communicating with the inlet side of the valve, a relief valve chamber 19 directly communicating with the outlet port 18, a pressure control valve port 20 communicating the passage 16 in the housing and the relief valve chamber 19, and a passage in the housing. Extension passage 21 communicating with the downstream side of 16
And a relief valve port 22 that communicates with the relief valve chamber 19. The pressure control valve port 20 and the relief valve port 22 are parallel to each other between the inlet port 15 and the outlet port 18. Has become.

In the passage 16 in the housing, a closed bellows device 23 in which carbon dioxide in a supercritical state is sealed is disposed as a pressure / temperature sensitive means. The bellows device 23 includes a bellows body 25 having an upper end member 24 integrally therewith.
A lower end member 26 welded to the lower end of the bellows main body 25 to close the lower end of the bellows main body 25;
A sealing ball 28 that closes the bellows by closing the injection hole 27 formed in the inner stopper member 29, an internal stopper member 29 having an upper end fixed to the upper end member 24, an upper flange portion 30 and a lower end member 26 of the internal stopper member 29, And a compression coil spring 31 provided between them.

In the bellows chamber 37 of the bellows device 23, a supercritical carbon dioxide gas is sealed at a density for optimizing the operation. It operates according to the balance of the refrigerant pressure at the outlet side of the radiator 2 with respect to the sum of the pressure generated in response to the refrigerant temperature at the outlet side of the heat sink 2 and the pressure due to the spring force of the compression coil spring 31 acting as a bias spring. .

A valve holding member 32 is fixed to an upper end portion of the bellows device 23, and a valve 33 for pressure control using a ball valve is fixed to the valve holding member 32. The pressure control valve element 33 is driven by the bellows device 23 to open / close and set the opening of the pressure control valve valve port 20.

The relief valve chamber 19 is provided with a relief valve element 34 composed of a ball valve element for opening and closing the relief valve port 22. Further, in the relief valve chamber 19, there is a relief valve element 3 between the spring retainer member 35 engaged with the relief valve element 34 and the spring retainer member 17 screwed to the valve housing 13.
A relief pressure setting spring 36 is provided by a compression coil spring for urging the valve 4 in the valve closing direction. The set pressure of the relief valve 34 may be set to about 9 MPa in the case of carbon dioxide refrigerant.

Since the extension passage 21 communicates with the downstream side of the in-housing passage 16, the in-housing passage 16 is located upstream of the relief valve port 22, and when the relief valve body 34 is opened, the pressure control Even when the valve element 33 is closed, a flow of fluid (refrigerant) occurs in the passage 16 in the housing located outside the bellows body 25, and the bellows device 23
It is exposed to the refrigerant flowing toward the evaporator 3.

Next, the above-described pressure control valve 10 with a relief valve is used.
The operation of will be described. Normally, the relief valve body 34 closes the relief valve port 22 by the spring force of the relief pressure setting spring 36, and the bellows device 23 operates in response to the pressure and temperature of the refrigerant at the outlet side of the radiator 2. Thus, the pressure control valve element 33 operates as a high-pressure control valve, and controls the degree of communication between the radiator 2 and the evaporator 3 in response to the pressure and temperature of the refrigerant on the outlet side of the radiator 2. As a result, the pressure on the outlet side of the radiator 2 is controlled, and by this control, the operation along the optimal control line is normally performed, and the operation with a high coefficient of performance is performed.

When the cooling load is small and the pressure on the side of the evaporator 3 is low under the condition that the high-pressure side pressure is high, the relief valve port 22 is opened against the spring force of the relief pressure setting spring 36 and the pressure control valve is opened. The communication between the radiator 2 and the evaporator 3 is increased by bypassing the valve port 20 for use. Thereby, power saving can be achieved even when the cooling load is small.

At the time of startup, the radiator 2 and the evaporator 3 are closed with the pressure control valve valve port 20 closed.
In other words, when the difference between the discharge pressure and the suction pressure of the compressor 1 exceeds a predetermined value, the relief valve port 22 opens against the spring force of the relief pressure setting spring 36, The radiator 2 and the evaporator 3 communicate with each other bypassing the valve port 20 for the pressure control valve, and the refrigerant flows through the passage 16 in the housing. Thereby, the bellows device 23 detects the normal temperature at the outlet side of the radiator 2 and the communication between the radiator 2 and the evaporator 3 is set accordingly. Even if the internal pressure is high, normal operation can be performed promptly.

Also, when the rotation speed of the compressor 1 rises and the pressure on the radiator 2 side rises sharply, the relief pressure setting spring 3
The relief valve port 22 is opened against the spring force of No. 6, and the radiator 2 and the evaporator 3 communicate with each other, so that a function as a safety valve can also be obtained.

[0031]

As can be understood from the above description, according to the supercritical vapor compression cycle device according to the first aspect of the present invention, the high pressure control valve is sensitive to the pressure and temperature of the refrigerant at the outlet side of the radiator. By controlling the degree of communication between the radiator and the evaporator, the pressure at the outlet of the radiator is controlled, and this control normally operates along the optimal control line, and the pressure and evaporation of the refrigerant at the outlet of the radiator are controlled. When the pressure difference between the pressure of the refrigerant on the inlet side of the vessel and the pressure exceeds a predetermined value, the relief valve is opened to save power when the cooling load is small under high pressure on the high pressure side. Proper operation of the cycle device is guaranteed.

[0032] According to the supercritical vapor compression cycle device according to the second aspect of the present invention, the high pressure control valve responds to the pressure and temperature of the refrigerant at the outlet side of the radiator to communicate and shut off the radiator and the evaporator. In addition, by controlling the degree of communication, the pressure at the outlet of the radiator is controlled, and by this control, the operation along the optimal control line is performed at normal times, and the pressure of the refrigerant at the outlet of the radiator and the refrigerant at the inlet of the evaporator are controlled. When the pressure difference with the pressure is equal to or greater than a predetermined value, the relief valve opens to guarantee the operation of the supercritical vapor compression cycle device corresponding to the need for a high driving force when the cooling load is small, Also, if the relief valve opens, even if the high-pressure control valve is closed, a fluid flow occurs in the pressure / temperature sensitive chamber, and the pressure / temperature sensitive means causes the flow of the refrigerant from the radiator to the evaporator to proceed. And the pressure and temperature sensitive means It comes to respond, quick start-up of the supercritical vapor compression cycle device during Kosoto temperature is ensured.

According to the pressure control valve with the relief valve according to the third aspect of the present invention, the pressure control valve body is driven by the pressure / temperature sensitive means to open / close and set the opening of the pressure control valve port. When the differential pressure across the relief valve valve port exceeds the relief pressure set by the relief pressure setting spring, the relief valve body opens and the pressure control valve valve port is connected in a bypass form, making it compact. A composite valve is obtained.

According to the pressure control valve with the relief valve according to the fourth aspect of the present invention, when the relief valve is opened, a fluid flows in the pressure / temperature sensitive chamber even if the high pressure control valve is closed. The pressure / temperature sensitive means is exposed to the flow of the fluid in the pressure / temperature sensitive chamber, and the pressure / temperature sensitive means becomes sensitive to the pressure and temperature of the fluid flowing through the pressure / temperature sensitive chamber. The means can be operated normally immediately.

According to the pressure control valve with the relief valve according to the fifth aspect of the present invention, the pressure control valve body is driven by the sealed bellows device which is a pressure / temperature sensitive means, and the valve port for the pressure control valve is opened and closed. The opening is set stably over a long period of time.

According to the pressure control valve with the relief valve according to the sixth aspect of the present invention, in the supercritical vapor compression cycle device, the radiator transfers from the radiator to the evaporator in response to the pressure and temperature of the refrigerant at the outlet side of the radiator. A composite valve comprising a high-pressure control valve for controlling the flow rate of the flowing refrigerant and a relief valve for opening when the pressure difference between the pressure of the refrigerant at the outlet of the radiator and the pressure of the refrigerant at the inlet of the evaporator is equal to or higher than a predetermined value. It can be used for normal operation along the optimal control line, high driving force is required when the cooling load is small, and the internal pressure in the diaphragm room and bellows room is high due to high outside temperature Thus, proper operation of the supercritical vapor compression cycle device is compatible.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a supercritical vapor compression cycle device according to the present invention.

FIG. 2 is a sectional view showing one embodiment of a pressure control valve with a relief valve according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Radiator 3 Evaporator 7 High-pressure control valve 8 Relief valve 10 Pressure control valve with relief valve 13 Valve housing 15 Inlet port 16 Passage in housing 18 Outlet port 19 Relief valve chamber 20 Pressure control valve port 22 Relief valve Port 23 Bellows device 33 Pressure control valve element 34 Release valve element 36 Release pressure setting spring 37 Bellows chamber

Claims (6)

[Claims] 1. A supercritical vapor compression cycle device in which a refrigerant such as carbon dioxide gas circulates sequentially through a compressor, a radiator, and an evaporator, and is operated in a supercritical region. A high-pressure control valve that is provided in the middle of the passage and controls the degree of communication between the radiator and the evaporator in response to the pressure and temperature of the refrigerant at the outlet of the radiator to control the pressure at the radiator outlet. A pressure difference between the pressure of the refrigerant at the outlet of the radiator and the pressure of the refrigerant at the inlet of the evaporator, provided in parallel with the high-pressure control valve in the middle of the refrigerant passage from the radiator to the evaporator. A supercritical vapor compression cycle device, comprising: a relief valve that opens when is greater than or equal to a predetermined value. 2. A supercritical vapor compression cycle device in which a refrigerant such as carbon dioxide gas circulates sequentially through a compressor, a radiator, and an evaporator, and is operated in a supercritical region. It is provided in the middle of the passage, and is driven by pressure / temperature sensing means that senses the pressure and temperature of the refrigerant flowing from the radiator to the evaporator to control the communication / cutoff and the degree of communication between the radiator and the evaporator. A high-pressure control valve for controlling the pressure on the outlet side of the radiator; and a pressure controller for the refrigerant on the outlet side of the radiator, which is provided in parallel with the high-pressure control valve in the middle of the refrigerant passage from the radiator to the evaporator. The valve is opened when the differential pressure between the pressure and the pressure of the refrigerant on the inlet side of the evaporator is equal to or higher than a predetermined value, so that the pressure / temperature sensitive means is exposed to the refrigerant flowing from the radiator to the evaporator. Having a relief valve and A supercritical vapor compression cycle device characterized by the above-mentioned. 3. A valve housing having a pressure control valve port and a relief valve port in a parallel relationship, a pressure / temperature responsive means provided in the valve housing and responsive to pressure and temperature; A pressure control valve element driven by the temperature sensing means to open and close the pressure control valve port and set the opening degree; a relief valve element for opening and closing the relief valve valve port; and closing the relief valve element A pressure control valve with a relief valve, comprising: a relief pressure setting spring that biases in a direction. 4. The pressure / temperature sensitive chamber is disposed in a pressure / temperature sensitive chamber formed upstream of the relief valve port, and the pressure / temperature sensitive chamber is opened when the relief valve element opens. 4. A pressure control valve with a relief valve according to claim 3, wherein a flow of fluid is generated in the fluid, and the pressure / temperature sensitive means is exposed to the flow of the fluid. 5. The pressure control valve with a relief valve according to claim 3, wherein the pressure / temperature sensitive means is a sealed bellows device. 6. A supercritical vapor compression cycle device operated in a supercritical region in which a refrigerant such as carbon dioxide gas circulates in order through a compressor, a radiator, and an evaporator, and a refrigerant from the radiator to the evaporator. A high-pressure control valve that is provided in the middle of the passage and controls the flow rate of the refrigerant flowing from the radiator to the evaporator in response to the pressure and temperature of the refrigerant on the outlet side of the radiator;
It is used as a combined valve with a relief valve that opens when the pressure difference between the pressure of the refrigerant on the outlet side of the radiator and the pressure of the refrigerant on the inlet side of the evaporator is greater than or equal to a predetermined value. A pressure control valve with a relief valve according to any one of claims 3 to 5.