JPH10325479A - Cold storage and refrigerating device, refrigerant bypass valve for correcting flow rate, and temperature expansion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cold storage and refrigerating device to perform proper correction of a flow rate of a refrigerant during a low condensing pressure without exercising an influence on the opening characteristics of a temperature expansion valve when a condensing pressure is in a steady pressure state. SOLUTION: In a cold storage refrigerating device, a circulation refrigerant flow rate is controlled corresponding to a temperature load amount of an evaporator 9, and a temperature expansion valve 7 to keep the degree of superheat of a refrigerant on the outlet side of the evaporator is located in a refrigerant circulation route. A bypass valve 101 for correcting a refrigerant flow rate provided with a valve element 113 to open and close a bypass passage 101 and a snap action pressure-sensitive element 131 turned over and opened and closed in a direction in which the valve element 113 is opened is arranged in the middle of a bypass passage 99 bypassing the temperature expansion valve 7. When a refrigerant pressure Pc on the outlet side of a condenser 3 exceeds a pressure equivalent to mechanical resistance of the snap action pressure-sensitive element 131, the snap action pressure-sensitive element 131 effects snap action to turn over and deform in a direction in which the valve element 113 is closed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating / refrigeration apparatus, a bypass valve for correcting a refrigerant flow rate, and a temperature expansion valve, and more particularly, to controlling a flow rate of a circulating refrigerant in accordance with a temperature load of an evaporator to evaporate. Refrigeration apparatus including a temperature expansion valve of a type that maintains the degree of superheat of the refrigerant at the outlet of the vessel at a predetermined value, and a bypass valve for correcting the flow rate of refrigerant used in the refrigeration apparatus, and a temperature expansion valve, particularly the outlet side of a condenser The refrigerant flow correction when the refrigerant pressure is lower than a specified value.

[0002]

2. Description of the Related Art In general, in a refrigerating and refrigerating apparatus, a flow rate of a circulating refrigerant flowing from a condenser to an evaporator is controlled by a temperature expansion valve in accordance with a temperature load of the evaporator. Is maintained at a predetermined value.

[0003] The flow rate of the refrigerant by the temperature expansion valve is determined by the refrigerant pressure at the outlet side of the condenser which determines the refrigerant pressure difference before and after the temperature expansion valve (hereinafter sometimes abbreviated as condensation pressure), and the evaporator inlet (expansion valve outlet). ) Side and the opening amount of the temperature expansion valve.

When the condensing pressure decreases, the refrigerant pressure difference before and after the expansion valve decreases, and the refrigerant state at the expansion valve inlet side becomes a gas-liquid two-phase state. In addition, the refrigerant temperature (degree of superheat) at the evaporator outlet side becomes extremely high, and it becomes difficult to control the temperature. As a result, the degree of superheat of the refrigerant sucked into the compressor becomes extremely high, the temperature of the refrigerant discharged from the compressor increases accordingly, and insufficient return of the refrigerating machine oil to the compressor occurs. Destruction may occur.

[0005] When the condensing pressure is lowered, the cooling and dehumidifying effects are reduced because the capacity of the evaporator cannot be ensured, and the capacity of the evaporator is reduced because the heat exchange efficiency is reduced due to the freezing of the evaporator. The cooling effect and the dehumidifying effect are also reduced.

[0006] The condensing pressure (temperature) in the refrigerator is basically determined by the heat exchange capacity of the condenser, the load temperature (outside air temperature) and the amount of heat exchanged (refrigerant circulation amount).
There is a refrigerating and refrigerating apparatus that keeps the condensing pressure at a predetermined value by controlling the condensing pressure.

When the condenser is of a water-cooled type, the condensing pressure is determined by the temperature and flow rate of the cooling water. By controlling the flow rate of the cooling water with respect to the pressure, the condensing pressure (temperature) is maintained at the set pressure.

When the condenser is of an air-cooled type, the condensation pressure is determined by the outside air temperature and the air volume of the cooling fan. Therefore, the refrigerant bypass type condensation pressure control valve (HPR) controls the refrigerant flowing through the condenser. The condensing pressure (temperature) is maintained at a set pressure by controlling the flow rate or by controlling the rotation speed of the cooling fan.

However, the above-mentioned condensing pressure control increases the load on the compressor and is a control against energy saving.
In addition, when the temperature is low in winter or the like, particularly at the time of startup, the condensing temperature is low, and a required condensing pressure may not be obtained.

In addition to this, immediately after stopping the compressor,
The condenser on the condenser side, that is, the downstream side of the compressor has high temperature and high pressure, and the refrigerant on the evaporator side, that is, the upstream side of the compressor has low temperature and low pressure. When the supply of the refrigerant from the side to the evaporator side is cut off and the compressor is driven again in the same state, a large load is applied to the compressor due to the pressure difference between the upstream and downstream sides of the compressor,
For example, when a compressor is driven by using the rotation of an engine such as a car air conditioner, there is a possibility that a failure occurs due to the load not only in the compressor but also in a power supply source such as an engine.

In view of the above problems, Japanese Patent Application Laid-Open
In the temperature expansion valve disclosed in Japanese Patent No. 142175, a spring for setting the degree of superheat for urging the valve body in the valve closing direction is formed of a temperature-sensitive shape memory alloy by a spring, and the condensing temperature is made of a shape memory alloy. A direct sensing is performed by a spring. When the condensing temperature is low, the superheat degree setting spring pressure is lowered to increase the opening amount of the temperature expansion valve and secure the supply amount of the refrigerant to the evaporator as compared with when the condensing temperature is high. Like that.

An expansion valve using a snap action pressure-sensitive element (reversing leaf spring) is disclosed in Japanese Utility Model Laid-Open No. 5-5497.
In Japanese Patent Application Publication No. 2 (1993) -207, the pressure of the low-pressure chamber flowing through the outlet-side refrigerant flow path of the evaporator is changed by the difference between the pressure of the high-pressure chamber that is given a pressure that changes in accordance with the temperature of the refrigerant discharged from the evaporator. A reversing leaf spring is provided, and when the pressure difference exceeds a predetermined value, the maximum lift amount of the valve body is expanded by reversing operation of the reversing leaf spring, and the amount of refrigerant supply to the evaporator is increased by increasing the opening amount of the expansion valve. Are shown.

Another expansion valve using a snap action pressure sensitive element (reversing leaf spring) is disclosed in Japanese Utility Model Laid-Open No. 5-54.
No. 973 discloses that the pressure of the low-pressure chamber flowing through the outlet-side refrigerant flow path of the evaporator is changed by the difference between the pressure of the high-pressure chamber which is given a pressure that changes in accordance with the temperature of the refrigerant discharged from the evaporator. A reversing leaf spring is provided, and when the pressure difference exceeds a predetermined value, the maximum lift amount of the valve body is reduced by the reversing operation of the reversing leaf spring, the opening amount of the expansion valve is reduced, and the amount of refrigerant supplied to the evaporator is reduced. An expansion valve is shown that reduces the overload and avoids overloading the compressor.

[0014]

Problems to be Solved by the Invention JP-A-60-1421
The temperature expansion valve disclosed in Japanese Patent Publication No. 75 can achieve the intended purpose of increasing the opening amount of the temperature expansion valve when the condensing temperature (pressure) is low, and ensuring the supply of the refrigerant to the evaporator. However, with this thermal expansion valve, it is difficult to design and adjust the shape memory alloy spring to the required characteristics, and this affects the valve opening characteristics of the thermal expansion valve in a steady state (when the condensing pressure is a steady pressure). There is a possibility that the performance of the freezer / refrigerator at all times is reduced.

The expansion valve disclosed in Japanese Utility Model Laid-Open No. 5-54972 is designed to control the pressure of the low-pressure chamber flowing through the refrigerant flow path on the outlet side of the evaporator and the pressure that changes in accordance with the temperature of the refrigerant discharged from the evaporator. If the difference from the given pressure of the high-pressure chamber becomes equal to or more than a predetermined value, in other words, if the degree of superheat becomes equal to or more than a predetermined value, the reversing leaf spring performs a reversing operation, increasing the opening amount of the expansion valve and increasing the evaporator. Since the amount of refrigerant supplied to the evaporator is ensured, the amount of refrigerant supplied to the evaporator does not increase when the degree of superheat exceeds a predetermined value, and the refrigerant flow rate correction at low condensing pressure cannot be performed properly. In addition, in this expansion valve, since the reversing leaf spring directly sets the maximum valve opening amount of the expansion valve, in order to obtain a required refrigerant supply characteristic, structural precision is required.

The expansion valve disclosed in Japanese Utility Model Laid-Open Publication No. 5-54973 is designed to control the pressure of the low-pressure chamber flowing through the outlet-side refrigerant flow path of the evaporator and the pressure that changes in accordance with the temperature of the refrigerant discharged from the evaporator. If the difference from the given pressure of the high-pressure chamber becomes equal to or more than a predetermined value, in other words, at a high load, the reversing leaf spring operates reversely, reducing the amount of opening of the expansion valve and reducing the amount of refrigerant supplied to the evaporator. Since the load is reduced, the driving load of the compressor can be prevented from becoming excessive when the load is high, such as at the time of starting, but the refrigerant flow rate correction at the time of low condensing pressure cannot be performed.

The present invention has been made in view of the above-mentioned problems, and does not affect the valve opening characteristics of the temperature expansion valve when the condensing pressure is in a steady pressure state. It is an object of the present invention to provide a refrigeration apparatus, a bypass valve for refrigerant flow correction, and a temperature expansion valve, which can appropriately correct refrigerant flow and prevent unnecessary load from being applied when the compressor is driven.

[0018]

In order to achieve the above object, a refrigeration apparatus according to the first aspect of the present invention controls a flow rate of a circulating refrigerant in accordance with a temperature load of an evaporator. In a refrigerating and refrigerating apparatus having a temperature expansion valve for maintaining a superheat degree of a refrigerant at an outlet side at a predetermined value in a refrigerant circulation path, a bypass valve for correcting a refrigerant flow rate is provided in a bypass passage that bypasses the temperature expansion valve. The bypass valve for flow rate correction snap-actions in response to the refrigerant pressure at the outlet side of the condenser and the valve element that opens and closes the bypass passage, and opens the valve element when the refrigerant pressure is equal to or lower than a predetermined value. And a snap action pressure-sensitive element.

The bypass valve for correcting the refrigerant flow according to the third aspect of the invention controls the circulating refrigerant flow in accordance with the temperature load of the evaporator, and maintains the superheat degree of the refrigerant at the evaporator outlet side at a predetermined value. A refrigerant flow rate correction bypass valve used in a refrigeration apparatus having a temperature expansion valve in a refrigerant circulation path, the refrigerant flow rate correction bypass valve is provided in the middle of a bypass passage that bypasses the temperature expansion valve, A valve element that opens and closes the bypass passage, and a snap action pressure-sensitive element that performs a snap action in response to the refrigerant pressure on the outlet side of the condenser and opens the valve element when the refrigerant pressure is equal to or less than a predetermined value. It is what you have.

According to a fifth aspect of the present invention, there is provided a temperature expansion valve for controlling a flow rate of a circulating refrigerant in accordance with a temperature load of an evaporator to maintain a superheat degree of a refrigerant at an evaporator outlet side at a predetermined value. A temperature expansion valve for bypassing a main valve port for controlling a flow rate of a circulating refrigerant in accordance with a temperature load of an evaporator to connect an inlet port and an outlet port, and the bypass passage. And a snap action pressure sensitive element that snaps in response to the refrigerant pressure on the outlet side of the condenser and opens the bypass valve when the refrigerant pressure is equal to or lower than a predetermined value. It is what has been.

The refrigeration apparatus according to the second aspect of the present invention is the refrigeration apparatus according to the first aspect, and the bypass valve for correcting the refrigerant flow rate according to the fourth aspect of the invention is the third aspect. In the refrigerant flow rate correction bypass valve, the temperature expansion valve according to the invention according to claim 6 is the temperature expansion valve according to claim 5,
On one side of the snap action pressure sensing element, a movement space chamber is defined which defines the amount of movement of the snap action pressure sensing element toward the valve closing side by the snap action in response to the refrigerant pressure on the outlet side of the condenser. A pressure chamber is provided on the other side of the snap action pressure sensitive element for receiving a refrigerant pressure at the outlet side of the condenser, and the snap action pressure sensitive element is configured such that the pressure of the pressure chamber is the snap action pressure sensitive element. When the pressure is equal to or higher than the mechanical counter pressure, the pressure in the pressure chamber is reversed to the valve closing side against the mechanical counter pressure, and the pressure in the pressure chamber is reduced to the mechanical counter pressure. In the following cases, the valve is reversely deformed to the valve-opening side by the mechanical counter pressure.

In the refrigeration apparatus according to the first aspect of the present invention, when the refrigerant pressure (condensation pressure) on the outlet side of the condenser falls below a predetermined value, the snap action pressure-sensitive element of the bypass valve for correcting the refrigerant flow rate has a snap action. Then, the valve body of the bypass valve for refrigerant flow correction is opened, and the refrigerant flows through the bypass passage. Thereby, the circulating refrigerant flow rate such as the refrigerant supply amount to the evaporator increases.

In the refrigeration apparatus according to the second aspect of the present invention, the pressure in the pressure chamber of the bypass valve for correcting the refrigerant flow, that is, the refrigerant pressure on the outlet side of the condenser is set in the snap action pressure sensitive element itself. When the pressure is equal to or higher than the mechanical opposition equivalent pressure, the pressure in the pressure chamber is reversed to the valve closing side against the mechanical opposition equivalent pressure, and the pressure in the pressure chamber becomes lower than the mechanical opposition equivalent pressure of the snap action pressure sensitive element. At a certain time, that is, at the time of low condensing pressure, the valve is reversely deformed to the valve-opening side by the mechanical counter pressure.

According to the third aspect of the present invention, when the refrigerant pressure (condensing pressure) on the outlet side of the condenser falls below a predetermined value, the snap action of the snap action pressure-sensitive element causes the valve element to move. The valve opens to allow the refrigerant to flow through the bypass passage. Thereby, the circulating refrigerant flow rate such as the refrigerant supply amount to the evaporator increases.

In the bypass valve for correcting the refrigerant flow rate according to the present invention, the pressure in the pressure chamber, that is, the refrigerant pressure on the outlet side of the condenser is equal to the mechanical counter pressure set in the snap action pressure sensitive element itself. When it is above, when the pressure of the pressure chamber is reversed to the valve closing side against the mechanical counter pressure, the pressure of the pressure chamber is equal to or less than the mechanical counter pressure of the snap action pressure sensitive element, At the time of low condensing pressure, the valve is reversely deformed toward the valve opening side by the mechanical equivalent pressure.

In the temperature expansion valve according to the fifth aspect of the present invention, when the refrigerant pressure (condensation pressure) at the outlet of the condenser falls below a predetermined value, the bypass valve is opened by the snap action of the snap action pressure-sensitive element. Then, the refrigerant flows through the bypass passage. Thereby, the circulating refrigerant flow rate such as the refrigerant supply amount to the evaporator increases.

[0027] In the temperature expansion valve according to the sixth aspect of the present invention, the pressure in the pressure chamber, that is, the refrigerant pressure on the outlet side of the condenser is equal to or higher than the mechanical counter pressure set in the snap action pressure sensitive element itself. At times, the pressure in the pressure chamber is reversed to the valve closing side against the mechanical opposition equivalent pressure,
When the pressure in the pressure chamber is equal to or lower than the mechanical opposing pressure of the snap action pressure-sensitive element, that is, at the time of a low condensing pressure, the valve is reversely deformed to the valve opening side by the mechanical opposing equivalent pressure.

[0028]

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

(Embodiment 1) FIGS. 1 to 3 show a temperature expansion valve and a refrigeration apparatus including the temperature expansion valve according to the present invention. The refrigerating and refrigerating apparatus has a compressor 1, a condenser (condenser) 3, a receiver 5, a temperature expansion valve 7, and an evaporator (evaporator) 9 like the ordinary refrigerating and refrigerating apparatus. , 15, 17, 19a,
19b is connected in a loop.

The temperature expansion valve 7 has a housing body 21. The housing body 21 has an inlet port 23 and an outlet port (expansion chamber) 25, and has a main valve chamber 27 and a main valve port 29 between the inlet port 23 and the outlet port 25. Further, the evaporator 9 is provided in the housing body 21.
The through refrigerant passage 2 which forms a part of the refrigerant passage to the compressor 1
2 are formed, and refrigerant pipes 19 a and 19 b are connected to both sides of the through refrigerant passage 22.

The main valve chamber 27 is provided with a ball-shaped main valve element 31. The main valve body 31 closes the main valve port 29 by sitting on the valve seat 33, and quantitatively controls the valve opening (refrigerant flow rate) by the amount of separation (lift) from the valve seat 33.

The main valve chamber 27 has an adjustable spring retainer 3 screwed to the housing body 21 in an adjustable manner.
5, a valve body-side spring retainer 37, and a setting spring 39 provided between the adjustable spring retainer 35 and the valve body-side spring retainer 37.

The setting spring 39 is made of a normal spring material, and the spring load generated by the setting spring 39 is an upward spring load in the valve closing direction as viewed in FIG. 1 and bears an opposing spring load. .

Diaphragm cases 41 and 43 are attached to the housing body 21. A diaphragm 45 is stretched in the diaphragm cases 41 and 43,
Pressure chambers 47 and 49 are defined on both upper and lower sides of the diaphragm 45.

In the diaphragm case 43, the refrigerant pipe 1
A sealing pipe 51 which is used when sealing the same refrigerant as the refrigerant flowing through 1, 13, 15, 17, 19a, 19b into the pressure chamber 47, and is sealed after the sealing, is attached, and the pressure above the diaphragm 45 is increased. As in the prior art, the internal pressure of the chamber 47 is exposed to the connecting rod 57 extending across the through refrigerant passage 22 in the refrigerant flow from the evaporator 9 flowing through the through refrigerant passage 22, and this connecting rod 57 The temperature changes in accordance with the temperature of the refrigerant at the outlet side of the evaporator 9, which is transmitted to the pressure chamber 47 via the retainer 55 and the diaphragm 45.

The lower pressure chamber 49 of the diaphragm 45 is
The hole 53 communicates with the through refrigerant passage 22 and exerts a refrigerant pressure on the outlet side of the evaporator 9.

The pressure chamber 49 is provided with a retainer 55 responsive to the diaphragm 45, and the retainer 55 and the valve element 31 are connected to each other by a connecting rod 57 supported up and down by the housing body 21.

With the above structure (normal configuration), the main valve body 3
In 1, the valve opening amount is set in an equilibrium relationship between the valve opening force due to the pressure difference between the pressure chamber 47 and the pressure chamber 49 and the valve closing force by the setting spring 39. Accordingly, the temperature expansion valve 7 is set to the valve opening amount corresponding to the temperature load of the evaporator 9 and controls the flow rate of the circulating refrigerant according to the temperature load of the evaporator 9 as in the conventional case. And maintain the superheat at the specified value.

The housing main body 21 is formed with a bypass passage 59 which bypasses the main valve port 29 and connects the inlet port 23 and the outlet port 25 for communication. The bypass passage 59 is formed by the bypass passage inlet 59a. At the outlet port 25 by the bypass passage outlet 59b. In the housing body 21,
A bypass valve chamber 61 is formed at a position corresponding to the middle of the bypass passage 59. The bypass valve chamber 61 is sealed by a cover 67 airtightly attached to the housing body 21 by a snap ring 65 with the seal member 63 interposed therebetween.

The bypass valve chamber 61 is provided with a ball-shaped bypass valve body 69. The bypass valve body 69 closes the bypass valve port 73 formed between the bypass passage inlet 59 a and the bypass passage outlet 59 b by sitting on the valve seat 71, and separates from the valve seat 71 to bypass the valve. Open port 73.

A return spring 77 is provided between the cover 67 and the valve body-side spring retainer 75, and the return spring 77 urges the bypass valve body 69 in the valve closing direction.

The housing body 21 includes a sealing member 7.
9, spring retainer 81, snap action pressure sensitive element 8
3. The cover plate 85 is sequentially attached by the snap ring 87.

The snap action pressure-sensitive element 83 is connected to the bypass valve body 69 by a connecting rod 91 movably supported in its own axial direction from the housing body 21, and the snap action of the snap action pressure-sensitive element 83 is performed. It is configured to be transmitted to the bypass valve body 69. And this snap action pressure sensitive element 83
The bypass valve body 69 is separated from the valve seat portion 71 and is reversely deformed in a direction to open the bypass valve port 73, and applies a pressure equal to or higher than the mechanical opposing equivalent pressure of the snap action pressure sensing element 83 itself to the connecting rod 91 side. , The bypass valve body 69 is configured to be seated on the valve seat portion 71 and reversely deformed in a direction to close the bypass valve port 73.

Further, between the snap action pressure sensing element 83 and the cover plate 85, the bypass valve body 69 reverses the opening direction of the bypass valve port 73 by the pressure received by the snap action pressure sensing element 83 from the connecting rod 91 side. In order to define the amount of movement of the snap action pressure sensing element 83 in the axial direction of the connecting rod 91 when deforming, the moving space chamber in which the position where the snap action pressure sensing element 83 contacts the cover plate 85 is the maximum movement amount. 82 is defined. A pressure chamber 89 is defined between the snap action pressure-sensitive element 83 and the connecting rod 91, that is, between the spring retainer 81 and the snap action pressure-sensitive element 83. The pressure chamber 89 has an outlet of the condenser 3 in the pressure chamber 89. Side refrigerant pressure (condensing pressure Pc) is introduced.

Then, by the connection between the snap action pressure sensing element 83 and the bypass valve body 69 via the connecting rod 91, the bypass valve body 69 is deformed by reversing the snap action pressure sensing element 83 to the left as viewed in FIG. When in the state, the spring force of the return spring 77 is seated on the valve seat portion 71 to close the bypass valve port 73, and the snap action pressure-sensitive element 83 is reversely deformed to the right side (illustrated state) in FIG. In this state, the bypass valve port 73 is opened apart from the valve seat 71 against the spring force of the return spring 77.

When the pressure in the pressure chamber 89, that is, the condensing pressure Pc is equal to or higher than a predetermined value, that is, the pressure equivalent to the mechanical resistance of the snap action pressure-sensitive element 83, the snap-action pressure-sensitive element 83 is turned on. The state is reversed to the left as viewed in FIG. 3 by snap action against the equivalent pressure, and the pressure in the pressure chamber 89 (condensing pressure Pc)
Is smaller than a predetermined value, that is, at the time of condensing pressure, the snap action is performed against the spring force of the return spring 77 by the mechanical opposing equivalent pressure of the snap action pressure sensing element 83, and the snap action is reversed to the right as viewed in FIG. become.

With the above configuration, if the condensing pressure Pc is equal to or higher than a predetermined value, the snap action pressure-sensitive element 83
And the bypass valve 6
9 is seated on the valve seat portion 71 by the spring force of the return spring 77 and closes the bypass valve port 73.

Therefore, in a steady state in which the condensing pressure Pc is equal to or higher than a predetermined value, the refrigerant flow rate in the bypass passage 59 becomes zero, and the circulating refrigerant flow rate in the refrigerating / refrigeration apparatus becomes the main valve element 31
Is determined as usual by the amount of valve opening.

On the other hand, when the condensing pressure Pc falls below a predetermined value, the snap action pressure-sensitive element 83 snaps against the spring force of the return spring 77 due to its mechanical opposing equivalent pressure, and as shown in FIG. The bypass valve body 69 is inverted and deformed to the right, and the bypass valve body 69 is pushed by the connecting rod 91 so that the valve seat 71
As the distance increases, the bypass valve port 73 is opened.

Therefore, when the condensing pressure Pc becomes equal to or lower than the predetermined value, the refrigerant flows through the bypass passage 59, and the flow rate of the circulating refrigerant in the refrigerating and refrigerating apparatus increases by the flow rate of the bypass refrigerant.

As a result, the flow rate of the refrigerant supplied to the evaporator 9 increases when the condensing pressure Pc is low, and does not affect the valve opening characteristics of the temperature expansion valve 7 when the condensing pressure Pc is in a steady pressure state. Insufficient refrigerant flow at low condensing pressure is eliminated.

Even when the bypass valve body 69 is opened at the time of low condensing pressure and the refrigerant is flowing through the bypass passage 59, the control for maintaining the superheat degree at the predetermined value by the temperature expansion valve 7 is performed in a feedback control manner. Also at this time, the degree of superheat is maintained at a predetermined value, and the performance of the refrigerator is maintained throughout the year.

Moreover, the refrigerant temperature (pressure) on the evaporator 9 side, that is, on the upstream side of the compressor 1, is on the condenser 3 side, that is, on the compressor 1 side.
Even when the compressor 1 is stopped in a state where the temperature is very lower than the refrigerant temperature (pressure) on the downstream side of the compressor 1, the refrigerant flows through the bypass passage 59 by opening the bypass valve body 69, so that the upstream side and the downstream side of the compressor 1 Since the difference in refrigerant pressure on the side is reduced, a large load is prevented from being applied to the compressor 1 at the time of subsequent re-driving, whereby the life of the compressor 1 is ensured.

Since the bypass valve body 69 takes only two positions, the valve closing position and the valve opening position, by the snap action of the snap action pressure sensing element 83, as shown in FIG. ON when the valve (bypass valve closed) and the predetermined value Q 'when the valve is open (bypass valve open)
The switching pressure is determined by the mechanical action equivalent pressure of the snap action pressure sensing element 83.

With these features, it is possible to arbitrarily set the characteristics of the snap action pressure-sensitive element 83 which responds to the condensing pressure, and to set the bypass valve opening / closing characteristics and the bypass refrigerant flow rate, that is, the refrigerant flow correction characteristics at low condensing pressure. The setting can be easily, accurately and appropriately performed independently of the function and the characteristic setting of the temperature expansion valve 7, and the adjustment after the mounting becomes unnecessary.

The opening and closing operation of the bypass valve body 69 is equivalent to a refrigerant flow correction device at the time of low condensing pressure by a combination of a pressure switch and an electromagnetic on-off valve, and can be realized at low cost and energy saving. it can.

The bypass passage 59 and the bypass valve 6
9. By mounting the bypass valve structure including the return spring 77, the snap action pressure sensing element 83, and the like in the temperature expansion valve 7, the mounting property and the space property are good.

(Embodiment 2) FIG. 5 shows a refrigerant flow correction bypass valve according to the present invention and a refrigeration apparatus including the refrigerant flow correction bypass valve. In FIG. 5, portions corresponding to those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and description thereof is omitted.

In the freezing and refrigeration apparatus according to this embodiment,
A bypass pipe 99 for bypassing the temperature expansion valve 7 and connecting the refrigerant pipes 15 and 17 is provided. In the middle of the bypass pipe 99, a refrigerant flow correction for opening and closing the bypass pipe 99 in an on / off manner. A bypass valve 101 is provided.

The refrigerant flow rate compensating bypass valve 101 has a housing body 103. Housing body 103
Are the inlet port 105 on the condenser 3 side, the outlet port 107 on the evaporator 9 side, the inlet port 105 and the outlet port 10.
7, a valve chamber 109 and a valve port 111 are provided.

The valve chamber 109 is provided with a ball-shaped valve element 113. The valve body 113 closes the valve port 111 by sitting on the valve seat 115, and opens the valve port 111 by separating from the valve seat 115.

The housing body 103 includes a sealing member 1
The spring retainer 121 is hermetically mounted by a snap ring 119 with the 17 interposed therebetween. Spring retainer 121
Between the spring retainer 123 and the valve body side spring 125
The return spring 125 urges the valve body 113 in the valve closing direction. Further, a seal member 127, a retainer 129, a snap action pressure-sensitive element 131, and a cover plate 133 are sequentially attached to the housing body 103.

The snap action pressure-sensitive element 131 is connected to the valve body 113 by a connecting rod 137 movably supported in its own axial direction from the housing main body 103. It is configured to be transmitted to the body 113.
The snap action pressure-sensitive element 131 is reversely deformed in a direction in which the valve body 113 is separated from the valve seat portion 115 and opens the valve port 111, and the snap-action pressure-sensitive element 131 itself has mechanical opposition. When a pressure equal to or higher than the pressure is received from the connecting rod 137 side, the valve body 113 is configured to reversely deform in a direction to close the valve port 111 by sitting on the valve seat 115.

The snap action pressure sensitive element 131
When the valve body 113 is reversely deformed in a direction in which the valve port 111 is opened by the pressure applied to the snap action pressure-sensitive element 131 from the connection rod 137 side, the connection rod 137 is positioned between the connection rod 137 and the cover plate 133. In order to regulate the amount of movement of the action pressure sensitive element 131, the snap action pressure sensitive element 131 is attached to the cover plate 133.
A moving space chamber 132 having a maximum moving amount at a position where the moving space 132 contacts is defined. Further, the pressure chamber 1 is located between the spring rod 129 and the snap action pressure-sensitive element 131 on the connection rod 137 side of the snap action pressure-sensitive element 13.
A refrigerant pressure (condensing pressure Pc) on the outlet side of the condenser 3 is introduced into the pressure chamber 135.

Then, by connecting the snap action pressure-sensitive element 131 and the valve body 113 via the connecting rod 137,
When the snap-action pressure-sensitive element 131 is in a state of being turned upside down as viewed in FIG. 5, the valve body 113 is seated on the valve seat 115 by the spring force of the return spring 125 to close the valve port 111, and On the other hand, when the snap action pressure sensing element 131 is in a state of being inverted and deformed downward (shown in FIG. 5) in FIG. 5, the valve port 111 is separated from the valve seat 115 against the spring force of the return spring 125. Become open.

When the pressure in the pressure chamber 135, that is, the condensing pressure Pc is equal to or higher than a predetermined value, that is, the pressure equivalent to the mechanical resistance of the snap action pressure-sensitive element 137, the snap-action pressure-sensitive element 131 is used. When the pressure (condensing pressure Pc) in the pressure chamber 135 becomes lower than a predetermined value, that is, at the time of a low condensing pressure, the snap action is sensed. The snap action is performed against the spring force of the return spring 125 by the mechanical opposing equivalent pressure of the pressure element 131, and the state is inverted and deformed downward as seen in FIG. 5.

With the above configuration, if the condensing pressure Pc is equal to or higher than the predetermined value, the snap action pressure-sensitive element 131 is in a state of being turned upside down in FIG.
Is seated on the valve seat 115 by the spring force of the return spring 125, and closes the valve port 111.

Accordingly, in the steady state where the condensing pressure Pc is equal to or higher than the predetermined value, the flow rate of the refrigerant in the bypass pipe 99 becomes zero, and the flow rate of the circulating refrigerant in the refrigerating / refrigerating apparatus is normally determined by the opening amount of the temperature expansion valve 7.

On the other hand, when the condensing pressure Pc falls below a predetermined value, the snap action pressure-sensitive element 131 snaps against the spring force of the return spring 125 due to its mechanical opposing equivalent pressure, and as shown in FIG. Invert to the lower side,
The valve body 113 is pushed by the connecting rod 137 and the valve seat 11
5, and the valve port 111 is opened.

Therefore, also in this embodiment, the condensing pressure P
When c becomes equal to or less than a predetermined value, the refrigerant flows through the bypass pipe 99, and the flow rate of the circulating refrigerant in the refrigerating / refrigeration apparatus is increased by the amount of the bypass refrigerant flow in a steady state.

As a result, the flow rate of the refrigerant supplied to the evaporator 9 increases when the condensing pressure Pc is low, without affecting the valve opening characteristics of the temperature expansion valve 7 when the condensing pressure Pc is in a steady pressure state. Insufficient refrigerant flow at low condensing pressure is eliminated.

Also in this embodiment, even when the valve element 113 is opened at the time of low condensing pressure and the refrigerant is flowing through the bypass pipe 99, the control for maintaining the degree of superheat at a predetermined value by the temperature expansion valve 7 is a feedback. Since the control is performed in a controlled manner, the degree of superheat is maintained at a predetermined value even at a low condensing pressure, and the performance of the refrigeration apparatus is maintained throughout the year.

Further, also in this embodiment, the evaporator 9
Even if the compressor 1 is stopped in a state where the refrigerant temperature (pressure) on the upstream side of the compressor 1, that is, the refrigerant temperature (pressure) on the condenser 3 side, that is, the refrigerant temperature on the downstream side of the compressor 1, is very low. Since the difference in refrigerant pressure between the upstream side and the downstream side of the compressor 1 is reduced by flowing the refrigerant through the bypass pipe 99 by opening the valve of the body 113, a large load is applied to the compressor 1 at the time of subsequent re-drive. Is also avoided, so that the life of the compressor 1 is ensured.

The sealing pipe 51 of the temperature expansion valve 7 is attached so as to be sensitive to the temperature of the refrigerant flowing through the refrigerant pipe 19 on the outlet side of the evaporator 9. They are connected by a capillary tube 52. This temperature expansion valve 7 may be a conventional one.

Also in this embodiment, the valve body 113
Takes only two positions, a valve closing position and a valve opening position, by the snap action of the snap action pressure-sensitive element 131. Therefore, similarly to the first embodiment, as shown in FIG. Is determined on / off by 0 when the valve is closed (bypass valve is closed) and a predetermined value Q ′ when the valve is opened (bypass valve is open), and the switching pressure is determined by the mechanical resistance of the snap action pressure sensitive element 131. Determined by the equivalent pressure.

With these features, it is possible to arbitrarily set the characteristics of the snap action pressure-sensitive element 131 that responds to the condensing pressure, and set the bypass valve opening / closing characteristics and the bypass refrigerant flow rate, that is, the refrigerant flow rate correction characteristics at low condensing pressure. The setting can be easily, accurately and appropriately performed independently of the function and the characteristic setting of the temperature expansion valve 7, and the adjustment after the mounting becomes unnecessary.

The opening and closing operation of the valve body 113 is equivalent to a refrigerant flow rate correction device at the time of low condensing pressure by a combination of a pressure switch and an electromagnetic on-off valve, and can be realized at low cost and energy saving. .

In this embodiment, the connection on the outlet side of the bypass pipe 99 is made in accordance with the required characteristics and the like, as shown by reference numeral 99a in FIG. As indicated by reference numeral 99b in FIG. 5, the design of the outlet portion of the evaporator 9 and the like can be easily changed.

[0079]

As will be understood from the above description, according to the refrigeration apparatus of the first aspect, the flow rate of the circulating refrigerant is controlled in accordance with the temperature load of the evaporator, and the outlet side of the evaporator is controlled. In a refrigerating and refrigerating apparatus having a temperature expansion valve for maintaining a degree of superheat of a refrigerant at a predetermined value in a refrigerant circulation path, a bypass valve for refrigerant flow correction is provided in a bypass passage that bypasses the temperature expansion valve, and the refrigerant flow correction is performed. A bypass valve for opening and closing the bypass passage, and a snap action in response to a refrigerant pressure on the outlet side of the condenser, and a snap action for opening the valve element when the refrigerant pressure is equal to or lower than a predetermined value. And a pressure-sensitive element.

Therefore, when the refrigerant pressure on the outlet side of the condenser becomes equal to or lower than a predetermined value, the snap action pressure-sensitive element performs a snap action, opens the valve body of the refrigerant flow rate correction bypass valve, and the refrigerant flows through the bypass passage. Because it will flow
Without affecting the valve opening characteristics of the temperature expansion valve when the condensing pressure is in the steady pressure state, the flow rate of the circulating refrigerant increases at low condensing pressure, and the shortage of refrigerant supply to the evaporator is eliminated. However, the required cooling and dehumidifying effects are obtained, and it is also possible to prevent insufficient refrigeration oil return to the compressor,
The life of the compressor can be ensured.

Further, when the compressor is stopped in a state where the refrigerant temperature (pressure) on the evaporator side, ie, the upstream side of the compressor, is much lower than the refrigerant temperature (pressure) on the condenser side, ie, the downstream side of the compressor. However, the refrigerant flows through the bypass passage due to the opening of the valve body of the refrigerant flow rate correction bypass valve by the snap action of the snap action pressure-sensitive element, and the flow rate of the refrigerant supplied from the condenser side to the evaporator side increases. Since the difference in refrigerant pressure between the upstream and downstream sides of the compressor is reduced,
It is also possible to prevent a large load from being applied to the compressor at the time of subsequent re-driving, whereby the life of the compressor can be ensured.

According to the bypass valve for correcting the refrigerant flow rate according to the third aspect of the invention, the circulating refrigerant flow rate is controlled in accordance with the temperature load of the evaporator, and the superheat degree of the refrigerant at the evaporator outlet side is set to a predetermined value. A refrigerant flow rate correction bypass valve used in a refrigeration apparatus having a temperature expansion valve in the refrigerant circulation path, wherein the refrigerant flow rate correction bypass valve is provided in the middle of a bypass passage that bypasses the temperature expansion valve. A valve element that opens and closes the bypass passage, and a snap action pressure-sensitive element that snaps in response to the refrigerant pressure on the outlet side of the condenser and opens the valve element when the refrigerant pressure is equal to or less than a predetermined value. And

For this reason, when the refrigerant pressure at the outlet side of the condenser becomes equal to or lower than a predetermined value, the snap action of the snap action pressure-sensitive element causes the valve body to open and the refrigerant to flow through the bypass passage. Does not affect the valve opening characteristics of the temperature expansion valve in the steady pressure state, the flow rate of the circulating refrigerant increases at low condensing pressure, and the shortage of refrigerant supply to the evaporator is eliminated. Air conditioning,
The dehumidifying effect can be obtained, and insufficient return of the refrigerator oil to the compressor can be avoided, and the life of the compressor can be ensured.

Further, when the compressor is stopped in a state where the refrigerant temperature (pressure) on the evaporator side, that is, the upstream side of the compressor, is much lower than the refrigerant temperature (pressure) on the condenser side, that is, the downstream side of the compressor. However, the refrigerant flows through the bypass passage by the opening of the valve body by the snap action of the snap action pressure-sensitive element, and the flow rate of the supplied refrigerant from the condenser side to the evaporator side increases, so that the upstream side and the downstream side of the compressor are increased. Since the difference in refrigerant pressure on the side is reduced, a large load is prevented from being applied to the compressor at the time of subsequent re-driving, whereby the life of the compressor can be ensured.

According to the fifth aspect of the present invention, the refrigeration system controls the circulating refrigerant flow rate in accordance with the temperature load of the evaporator, and maintains the superheat degree of the refrigerant at the evaporator outlet side at a predetermined value. In a temperature expansion valve for a refrigeration device, a bypass passage that connects and connects an inlet port and an outlet port by bypassing a main valve port portion for controlling a circulating refrigerant flow rate in accordance with a temperature load of an evaporator, A bypass valve element for opening and closing the bypass passage, and a snap action pressure-sensitive element for performing a snap action in response to the refrigerant pressure on the outlet side of the condenser and opening the bypass valve element when the refrigerant pressure is equal to or less than a predetermined value. Was incorporated.

When the refrigerant pressure on the outlet side of the condenser becomes equal to or lower than a predetermined value, the snap action of the snap action pressure-sensitive element opens the bypass valve body and the refrigerant flows through the bypass passage. Without affecting the valve opening characteristics of the temperature expansion valve when the pressure is in a steady pressure state, the circulating refrigerant flow rate increases at low condensing pressure, the shortage of refrigerant supply to the evaporator is eliminated, and even at low condensing pressure. The required cooling and dehumidifying effects can be obtained, and the occurrence of insufficient return of the refrigerating machine oil to the compressor can be avoided, and the life of the compressor can be ensured.

Further, when the compressor is stopped in a state where the refrigerant temperature (pressure) on the evaporator side, that is, on the upstream side of the compressor is much lower than the refrigerant temperature (pressure) on the condenser side, that is, on the downstream side of the compressor. However, the refrigerant flows through the bypass passage due to the opening of the bypass valve by the snap action of the snap action pressure-sensitive element, and the flow rate of the supplied refrigerant from the condenser side to the evaporator side increases. Since the difference in the refrigerant pressure on the downstream side is reduced, a large load is prevented from being applied to the compressor at the time of subsequent re-driving, whereby the life of the compressor can be ensured.

The refrigeration apparatus according to the second aspect of the present invention is the refrigeration apparatus according to the first aspect, and the bypass valve for refrigerant flow correction according to the fourth aspect of the invention is the third aspect. In the refrigerant flow rate correction bypass valve, the temperature expansion valve according to the invention according to claim 6 is the temperature expansion valve according to claim 5,
On one side of the snap action pressure sensing element, a movement space chamber is defined which defines the amount of movement of the snap action pressure sensing element toward the valve closing side by the snap action in response to the refrigerant pressure on the outlet side of the condenser. A pressure chamber is provided on the other side of the snap action pressure sensitive element for receiving a refrigerant pressure at the outlet side of the condenser, and the snap action pressure sensitive element is configured such that the pressure of the pressure chamber is the snap action pressure sensitive element. When the pressure is equal to or higher than the mechanical counter pressure, the pressure in the pressure chamber is reversed to the valve closing side against the mechanical counter pressure, and the pressure in the pressure chamber is reduced to the mechanical counter pressure. In the following cases, the valve is reversely deformed to the valve opening side by the mechanical opposing equivalent pressure.

For this reason, the valve body or the bypass valve body takes only two positions of the valve closing position and the valve opening position by the snap action of the snap action pressure sensing element. The valve opening / closing characteristics can be set accurately and reliably by the pressure equivalent to the mechanical action of the snap action pressure-sensitive element, and the refrigerant flow rate correction at low condensing pressure is highly accurate. In addition, the adjustment can be performed reliably, and the adjustment after the mounting becomes unnecessary.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing one embodiment of a temperature expansion valve and a refrigeration apparatus including the temperature expansion valve according to the present invention.

FIG. 2 is a side view of the thermal expansion valve shown in FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 1;

FIG. 4 is a graph showing the opening / closing characteristics of a bypass valve incorporated in the thermal expansion valve according to the present invention.

FIG. 5 is a system configuration diagram showing one embodiment of a refrigerant flow correction bypass valve and a refrigeration apparatus including the refrigerant flow correction bypass valve according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 3 Condenser 5 Condenser 7 Temperature expansion valve 9 Evaporator 21 Housing main body 22 Through refrigerant passage 23 Inlet port 25 Outlet port 27 Main valve room 29 Main valve port 31 Main valve body 39 Setting spring 45 Diaphragm 47, 49 Pressure chamber 51 sealing pipe 57 connecting rod 59 bypass passage 61 bypass valve chamber 69 bypass valve body 73 bypass valve port 77 return spring 82 moving space chamber 83 snap action pressure sensitive element 89 pressure chamber 91 connecting rod 99 bypass piping 101 bypass valve for refrigerant flow correction 105 Inlet port 107 Outlet port 109 Valve chamber 111 Valve port 113 Valve body 125 Return spring 131 Snap action pressure sensitive element 132 Moving space chamber 135 Pressure chamber 137 Connecting rod

Claims (6)

[Claims] 1. A refrigerating and refrigerating apparatus having a temperature expansion valve in a refrigerant circulation path for controlling a flow rate of a circulating refrigerant in accordance with a temperature load of an evaporator and maintaining a superheat degree of a refrigerant at an evaporator outlet side at a predetermined value. A refrigerant flow correction bypass valve is provided in the middle of a bypass passage that bypasses the temperature expansion valve, and the refrigerant flow correction bypass valve includes a valve body that opens and closes the bypass passage.
Refrigeration characterized by having a snap action pressure sensitive element that performs snap action in response to the refrigerant pressure on the outlet side of the condenser and opens the valve when the refrigerant pressure is equal to or lower than a predetermined value. Refrigeration equipment. 2. A movement defining an amount of movement of the snap action pressure sensing element to a valve closing side by a snap action in response to a refrigerant pressure at an outlet side of the condenser, on one side of the snap action pressure sensing element. A space room is defined,
On the other side of the snap action pressure sensitive element a pressure chamber is provided which is provided with refrigerant pressure on the outlet side of the condenser,
When the pressure in the pressure chamber is equal to or higher than the mechanical opposition equivalent pressure set in the snap action pressure-sensing element itself, the snap action pressure-sensing element responds to the mechanical opposition equivalent pressure by the pressure in the pressure chamber. Reverse deformation to the valve closing side,
2. The refrigeration apparatus according to claim 1, wherein when the pressure in the pressure chamber is equal to or lower than the mechanical equivalent pressure, the pressure chamber is reversely deformed to the valve opening side by the mechanical equivalent pressure. 3. A refrigerating and refrigerating apparatus having a temperature expansion valve in a refrigerant circulation path for controlling a flow rate of a circulating refrigerant in accordance with a temperature load of an evaporator and keeping a degree of superheat of the refrigerant at an evaporator outlet side at a predetermined value. A refrigerant flow rate correction bypass valve, wherein the refrigerant flow rate correction bypass valve is provided in the middle of a bypass passage that bypasses the temperature expansion valve, and a valve body that opens and closes the bypass passage, and an outlet of a condenser. A snap action pressure-sensitive element that performs a snap action in response to the refrigerant pressure on the side and opens the valve element when the refrigerant pressure is equal to or lower than a predetermined value. valve. 4. A movement that defines an amount of movement of the snap action pressure sensitive element to a valve closing side by a snap action in response to a refrigerant pressure at an outlet side of the condenser on one side of the snap action pressure sensitive element. A space room is defined,
On the other side of the snap action pressure sensitive element a pressure chamber is provided which is provided with refrigerant pressure on the outlet side of the condenser,
When the pressure in the pressure chamber is equal to or higher than the mechanical opposition equivalent pressure set in the snap action pressure-sensing element itself, the snap action pressure-sensing element responds to the mechanical opposition equivalent pressure by the pressure in the pressure chamber. Reverse deformation to the valve closing side,
4. The bypass valve according to claim 3, wherein when the pressure in the pressure chamber is equal to or lower than the mechanical counter pressure, the pressure chamber is reversely deformed to the valve opening side by the mechanical counter pressure. 5. A temperature expansion valve for a refrigerating and refrigerating apparatus for controlling a flow rate of a circulating refrigerant in accordance with a temperature load of an evaporator and maintaining a superheat degree of a refrigerant at an evaporator outlet side at a predetermined value. A bypass passage that bypasses the main valve port for controlling the circulating refrigerant flow rate in accordance with the load amount and connects and connects the inlet port and the outlet port; a bypass valve body that opens and closes the bypass passage; A temperature expansion valve incorporating a snap action pressure sensing element for performing a snap action in response to a refrigerant pressure on the outlet side and opening the bypass valve body when the refrigerant pressure is equal to or lower than a predetermined value. . 6. A movement defining a movement amount of the snap action pressure sensitive element to a valve closing side by a snap action in response to a refrigerant pressure at an outlet side of the condenser, on one side of the snap action pressure sensitive element. A space room is defined,
On the other side of the snap action pressure sensitive element a pressure chamber is provided which is provided with refrigerant pressure on the outlet side of the condenser,
When the pressure in the pressure chamber is equal to or higher than the mechanical opposition equivalent pressure set in the snap action pressure-sensing element itself, the snap action pressure-sensing element responds to the mechanical opposition equivalent pressure by the pressure in the pressure chamber. Reverse deformation to the valve closing side,
6. The thermal expansion valve according to claim 5, wherein when the pressure in the pressure chamber is equal to or less than the mechanical counter pressure, the pressure chamber is reversely deformed to the valve opening side by the mechanical counter pressure.