JPH031754Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Field of Industrial Application) The present invention relates to a refrigeration system, and more particularly to the structure of an injection control valve that controls injection of liquid refrigerant to the suction side of a compressor according to the temperature of discharged gas. (Prior Art) Conventionally, in a refrigeration system equipped with a refrigerant circuit in which a compressor, a condenser, an expansion mechanism, and an evaporator are sequentially connected, one end is connected to the downstream side of the condenser of the refrigerant circuit, and the other end is connected to the downstream side of the condenser. An injection circuit that is connected to the suction pipe of the compressor and injects liquid refrigerant into the suction side of the compressor, an on-off valve that opens and closes the injection circuit, and a temperature sensor that detects the temperature of the gas discharged from the compressor. The on-off valve opens and closes according to the temperature of the discharged gas detected by the temperature sensor, and opens when the temperature of the discharged gas exceeds a predetermined value, thereby injecting liquid refrigerant into the suction side of the compressor. There are well-known devices that prevent abnormal temperature rises due to compressor overload. (Problem to be solved by the invention) However, the conventional on-off valve for injection extension control requires combination with a temperature sensor,
Since the opening/closing operation is performed based on a detection signal from the temperature sensor, the structure is complicated, lacks reliability and durability, and is expensive. The present invention was developed in view of these points, and focuses on the characteristics of shape memory alloys that change shape due to temperature changes. By making the valve body automatically open and close due to this shape change, injection It is an object of the present invention to provide a simple structure, excellent reliability and durability, and to be able to perform control at low cost without requiring a temperature sensor or the like. (Means for solving the problem) In order to achieve this object, the solving means of the present invention is as shown in FIGS.
0, a refrigeration system equipped with a refrigerant circuit formed by sequentially connecting a condenser 11, an expansion mechanism 15, and an evaporator. One end is the condenser 11 of the refrigerant circuit.
It is connected to the downstream side, and the other end is connected to the suction pipe 1 of the compressor 10.
3, for injecting liquid refrigerant into the suction side of the compressor 10, and opening and closing the injection circuit according to the temperature of the discharge gas of the compressor 10, when the discharge gas temperature is less than a predetermined value. and an injection control valve A that is controlled to close and open when the temperature exceeds a predetermined value. The injection exit control valve A has an inlet 1a that is connected to the downstream side of the condenser 11 in the injection exit circuit, and an outlet 1b that is connected to the suction pipe 13 side of the compressor 10, and the inlet A valve box 1 in which a control flow passage X through which injection liquid refrigerant flows from 1a to an outlet 1b is formed, a valve seat 2 provided in the control flow passage X of the valve box 1, and a valve seat 2 in the valve seat 2. A valve body 3 that approaches and separates to open and close the control flow path a temperature-sensing section 4 having two flow ports 4b and a temperature-sensing flow path Y through which discharged gas flows from the first flow port 4a to the second flow port 4b; A valve rod 6 is disposed in the hot flow passage Y and is attached to the valve body 3.
When the temperature of the discharged gas flowing through the temperature-sensitive flow path Y is less than a predetermined value, the valve body 3 is maintained in a closed state, and when the temperature of the discharged gas exceeds a predetermined value, the valve body 3 is closed. The actuating body 5 made of a shape memory alloy changes its shape in response to a change in discharge gas temperature to open and close the valve body 3 so as to open the valve. (Function) Accordingly, in the present invention, when the temperature of the discharged gas from the compressor 10 is lower than a predetermined value, the valve body 3
Injection of liquid refrigerant is not performed when the valve is closed. When the discharge gas temperature exceeds a predetermined value, the valve body 3 opens and injects liquid refrigerant into the suction side of the compressor 10, thereby preventing an abnormal rise in temperature of the compressor 10 during overload. In that case, the temperature change of the discharged gas is sensed by the actuating body 5 itself made of a shape memory alloy, and the actuating body 5 functions as an actuator to open and close the valve body 3, so a conventional temperature sensor is used. This is not necessary and the structure is simple, and the valve body 3 can be opened and closed stably and reliably. Moreover, the shape memory alloy fabricated moving body 5 is placed in the temperature sensing flow path Y of the temperature sensing section 4, and is in the flow of the discharged gas whose temperature is to be sensed, so that the temperature of the discharged gas itself can be directly and accurately measured. As a result, the stability and reliability of the opening/closing movement of the valve body 3 are improved. (Example) Hereinafter, an example of the present invention will be described based on the drawings. The refrigeration system shown in FIG. 2 includes a refrigerant circuit in which a compressor 10, a condenser 11, an expansion mechanism 15, and an evaporator (not shown) are sequentially connected. The refrigerant circuit includes an injector, which has one end connected to the downstream side of the condenser 11 of the refrigerant circuit and the other end connected to the suction pipe 13 of the compressor 10, for injecting liquid refrigerant to the suction side of the compressor 10. circuit, and an injection control valve A that controls the injection circuit to open and close according to the temperature of the discharge gas of the compressor 10, to close when the discharge gas temperature is less than a predetermined value, and to open when the discharge gas temperature exceeds a predetermined value. ing. The injection control valve A has an inlet 1a that is connected to the downstream side of the condenser 11 in the injection circuit, and an outlet that is connected to the suction pipe 13 of the compressor 10 via an injection capillary tube 14. 1b, and is formed with a control flow path X through which liquid refrigerant for injection flows from the inlet port 1a to the outlet port 1b, and a valve provided in the control flow path X of the valve box 1. a seat 2, a needle valve body 3 that approaches and separates from the valve seat 2 to open and close the control flow path X, and a first flow port 4a connected to the compressor 10 side in the discharge pipe 12 of the compressor 10. A temperature-sensing section having a second flow port 4b connected to the condenser 11 side and having a temperature-sensitive flow path Y through which discharged gas flows from the first flow port 4a to the second flow port 4b. 4, disposed in the temperature sensing flow path Y of the temperature sensing section 4, and the valve body 3
When the temperature of the discharged gas flowing through the temperature-sensitive flow path Y is less than a predetermined value, the valve body 3 is maintained in a closed state, and when the temperature of the discharged gas exceeds a predetermined value, the above-mentioned valve body 3 is maintained in a closed state. The actuating body 5 is made of a shape memory alloy plate spring that changes its shape in response to a change in discharge gas temperature to open and close the valve body 3 in order to open the valve body 3. The actuating body 5 is disposed with its both ends locked to the temperature sensing section 4, and when the temperature of the discharge gas flowing through the temperature sensing flow path Y of the temperature sensing section 4 is higher than a predetermined value, the actuating body 5 is The shape changes as shown by the solid line, and this is transmitted to the valve body 3 via the valve stem 6 to open the valve body 3. On the other hand, when the temperature is lower than a predetermined value, the shape of the actuator 5 changes as shown by the imaginary line. The valve body 3 is configured to be operated to close the valve body 3. The term "low temperature" refers to the temperature below the temperature (As point) at which reverse transformation to the parent phase begins when the martensite phase in the shape memory alloy is heated, and the term "high temperature" refers to the temperature state at which the martensite phase of the parent phase starts to transform back to the parent phase (As point). Temperature at which transformation to phase begins (Ms point)
This refers to the temperature state above. As such shape memory alloys, various alloys as shown in the table below are used depending on the temperature range of the intended use.

[Table] Therefore, in the above embodiment, when the discharge gas temperature is lower than a predetermined value, the valve body 3 is closed and liquid refrigerant injection is not performed, and when the discharge gas temperature is higher than the predetermined value (for example, 130°C). When this occurs, the valve body 3 opens and injects the liquid refrigerant into the suction side of the compressor 10, and the injection exit capillary tube 14 prevents temperature abnormalities in the compressor 10 and condenser 11 during overload. The rise can be prevented. In that case, in the injection control valve A, the shape memory alloy moving body 5 senses the temperature change of the discharge gas flowing through the temperature-sensitive flow path Y of the temperature-sensing section 4 and changes its shape, and this shape change causes the valve body to change its shape. 3 opens and closes, eliminating the need for conventional temperature sensors, simplifying the structure, and stably and reliably opening and closing, improving durability and reliability. can be achieved. Moreover, since the actuating body 5 is disposed within the temperature-sensing flow path Y and is in the flow of the discharged gas whose temperature is to be sensed,
It is possible to directly sense the temperature change of the discharged gas and accurately sense the temperature without being affected by outside temperature etc.
Therefore, the opening and closing movements of the valve body 3 can be performed more stably, accurately, and reliably, and reliability can be further improved. The present invention is also applicable to various known valve types in addition to the needle valve type shown in the above embodiment. (Effects of the invention) As explained above, according to the invention, the valve body is opened and closed by a shape-memory alloy-made moving body that changes shape by directly sensing temperature changes in the gas discharged from the compressor, thereby discharging liquid refrigerant. Since the liquid refrigerant injection to the suction side of the compressor is controlled, injection extraction of liquid refrigerant in a refrigeration system can be automatically, stably and reliably controlled with a simple structure without requiring a temperature sensor or the like. Therefore, it is possible to provide a highly durable and reliable injection control valve at low cost.

[Brief explanation of the drawing]

The drawings illustrate the embodiments of the present invention.
The figure is a longitudinal sectional view of the injection control valve, and FIG. 2 is a system diagram of the refrigeration system. 1... Valve box, 1a... Inlet, 1b... Outlet, 2... Valve seat, 3... Valve body, 4... Temperature sensing part, 4
a...First distribution port, 4b...Second distribution port, 5...
Actuating body, 6... valve stem, 10... compressor, 11...
Condenser, 12...discharge pipe, 13...suction pipe, X...
...Control flow path, Y...Temperature-sensitive flow path.

Claims (1)

[Claims for Utility Model Registration] A refrigeration system equipped with a refrigerant circuit in which a compressor 10, a condenser 11, an expansion mechanism 15, and an evaporator are sequentially connected, one end of which is located downstream of the condenser 11 of the refrigerant circuit. an injection-extraction circuit for injecting liquid refrigerant into the suction side of the compressor 10, the other end of which is connected to the suction pipe 13 of the compressor 10; and an injection exit control valve A that is controlled to open and close, close when the discharge gas temperature is less than a predetermined value, and open when the discharge gas temperature exceeds the predetermined value, and the injection exit control valve A communicates with the downstream side of the condenser 11 in the injection exit circuit. A controlled flow path a valve box 1 formed with a valve seat 2, a valve seat 2 provided in a control flow path X of the valve box 1, and a valve seat 2 provided in the control flow path
a valve body 3 for opening and closing, and a discharge pipe 1 of the compressor 10
2, it has a first communication port 4a that is connected to the compressor 10 side and a second communication port 4b that is connected to the condenser 11 side, and the first communication port 4a leads to the second communication port 4b. Temperature-sensitive flow path Y through which discharged gas flows
A temperature-sensing section 4 formed with a temperature-sensing section 4 and a discharge gas disposed in a temperature-sensing flow path Y of the temperature-sensing section 4 and connected to the valve body 3 via a valve rod 6, and flowing through the temperature-sensing flow path Y. When the temperature of the discharged gas is less than a predetermined value, the valve body 3 is maintained in a closed state, and when the temperature of the discharged gas exceeds a predetermined value, the valve body 3 changes its shape to open the valve. A refrigeration device comprising an operating body 5 made of a shape memory alloy that opens and closes the body 3.