CN1237240A - Refrigeration circuit arrangement for refrigeration system - Google Patents

Abstract

A refrigeration circuit arrangement for a refrigeration system including, between the outlet of the condenser (4) and the inlet of the evaporator (8) of said circuit, a valve (20) of refrigerant fluid flow control, having a refrigerant fluid passage (22), whose cross section varies during the operation of the hermetic compressor (1) in a manner inversely proportional to the variation of the condensation temperature, in order to allow the condensed refrigerant fluid supplied to the evaporator (8) to have a temperature substantially correspondent to a nominal condensation temperature of the system.

Description

Refrigeration piping configuration of the refrigeration system

The present invention relates to a refrigerating pipeline configuration of a refrigerating system, which comprises a hermetic compressor mounted on a gas pumping pipeline comprising a condenser, an evaporator and a refrigerating fluid flow to the flow restrictor above the evaporator.

In a conventional refrigeration system, a refrigeration circuit basically includes a hermetic compressor, a condenser, a decompression component such as a capillary tube, and an evaporator in sequence.

In this pipeline, a hermetic compressor draws in low-pressure refrigerant gas, pumps it to a condenser, and turns it into a high-temperature, high-pressure gas. During passage through the condenser, the gas liquefies, dissipating its heat to the surrounding environment.

After reducing its pressure in the capillary tube, the refrigerated liquid flows from the condenser to the evaporator, where it becomes gaseous again and is pumped by the compressor to start a new working cycle.

The refrigerating fluid changes from liquid to gas during passing through the evaporator, absorbing heat in the environment where the evaporator is placed, and cooling the internal environment of the refrigerating device equipped with refrigerating pipelines.

In refrigeration circuits, the temperature of the evaporator, the pressure of the compressor, and the temperature and pressure in the condenser are controlled by capillary tubes whose dimensions vary with the predetermined average operating conditions of the system. Due to this rigid structure, the capillary does not allow the operation of the system to be optimized in its several operating phases (start-up, normal operation and shutdown). The size of the capillary is determined according to the optimum point of its operating performance.

The optimization of the capillary varies with the room temperature of the installation site of the refrigeration unit equipped with the refrigeration circuit, the temperature of the refrigerator, and the temperature of the condenser of the above-mentioned refrigeration circuit. The pressure inside the refrigeration system and thus the load on the compressor corresponds to each of these temperatures. The reduction in room temperature reduces the overall pressure in the system. In this state, the compressor will be pumping a small amount of gas and its efficiency will decrease. An increase in room temperature means an increase in the load on the compressor, requiring the compressor to output an additional load, which is necessary in order to increase the pumping of the refrigerant gas in the system. The increase of the load will cause the temperature of the compressor to rise, which may shorten its service life, and may cause damage to the valve or even burn out the motor.

A consequence of the increase in room temperature outside the refrigerated environment is an increase in the condensation temperature of the gas pumped by the compressor to the condenser. Since condensation is caused by heat exchange between the condenser and the environment, an increase in room temperature means an increase in the condensation temperature of the refrigerant fluid. The condensed refrigerant fluid enters the evaporator at a higher temperature, thereby reducing the evaporation efficiency and thereby reducing the cooling effect of the environment with which the evaporator exchanges heat.

In addition, in the conventional refrigeration piping configuration, when the temperature of the evaporator reaches a predetermined value and the compressor is shut down, the condensed fluid existing in the high pressure part of the system in the condenser will migrate to the evaporator of the above system. In the low pressure section, this migration of condensed refrigerant fluid from the various condensers to the evaporators results in a reduction in the efficiency of the refrigeration system and increases the energy consumption of the system. A solution to locally minimize these problems is to apply variable speed compressors. However, the effect of this solution is partial, since the capillary has a constant throttling effect, and with increasing rotor rotation, the suction pressure decreases, thus reducing the compressor efficiency and possibly increasing the mass flow not proportional to the increase in rotation.

It is therefore an object of the present invention to provide a refrigeration circuit arrangement for a refrigeration system which allows maximum efficiency of the compressor without requiring said compressor to operate under limiting operating conditions.

A specific object of the present invention is to provide a refrigeration circuit arrangement which can constantly regulate the flow of condensing fluid to the evaporator at a temperature close to the rated condensing temperature which takes into account the refrigeration of the refrigerated environment requirements and operating conditions of the load imposed on the compressor.

Another object of the present invention is to provide a refrigeration system having a refrigeration circuit which prevents the migration of heated refrigerant fluid from the condenser to the evaporator when the compressor is shut down.

The above object can be achieved by utilizing a refrigerating pipeline of a refrigerating system, the pipeline comprising: an airtight compressor; a condenser having an inlet and an outlet connected to the discharge port of the compressor; an evaporator having an inlet connected to the outlet of the condenser and export. The arrangement described above includes a refrigerant fluid flow control valve between the condenser outlet and the evaporator inlet, the valve having a refrigerant fluid passage whose cross-sectional area varies inversely proportional to the change in condensing temperature during operation of the hermetic compressor , so that the condensed refrigerant fluid flowing into the evaporator has a temperature substantially equal to the rated condensation temperature of the system. When the airtight compressor is shut down, the cross-section of the refrigerant fluid passage is closed, completely cutting off the fluid passage between the condenser and the evaporator.

Illustrate the present invention below with reference to accompanying drawing, accompanying drawing is:

Fig. 1 schematically shows the refrigerating pipeline of the refrigerating device such as refrigerator made by prior art;

Fig. 2 schematically shows the refrigerating pipeline shown in Fig. 1 made by the present invention;

Fig. 3 is a longitudinal sectional view schematically showing the refrigerant fluid flow control valve of the present invention.

As shown in Figure 1, a conventional refrigeration system includes a refrigeration pipeline, which includes: an airtight compressor 1 with a discharge port 2 and a pump suction inlet 3; a gaseous fluid inlet 5 of the discharge port 2 and a condensed fluid outlet 6 connected to the capillary 7; an evaporator 8 having a condensed fluid inlet 9 operatively connected to the capillary 7 and in fluid communication with the pump suction 3 of the hermetic compressor 1 The gas outlet 10.

In this pipeline, the airtight compressor 1 pumps low-pressure refrigerated gas and pumps it as high-pressure heated gas to the condenser. In the above-mentioned condenser, the above-mentioned gas is liquefied and dissipates its heat to the surrounding environment. Condensation occurs by heat exchange between the condenser 4 and its external environment.

The liquefied fluid passes through the capillary 7 to reduce the pressure of the above-mentioned gas, and then the gas enters the evaporator 8, and after heat exchange with the internal environment of the refrigerator, the gas is sucked by the compressor 1 again to start a new working cycle.

According to this structure, since there is a difference between the predetermined condensation rated temperature and the actual temperature at which the gas pumped into the condenser 4 by the compressor 1 is condensed, the heat exchange efficiency of the condenser 4 is lowered. This construction also suffers from the above-mentioned disadvantage of overloading the compressor.

According to the invention, the refrigerating circuit comprises a refrigerating fluid flow control valve 20 arranged between the condensed fluid outlet 6 of the condenser 4 and the condensed fluid inlet 9 of the evaporator 8, which valve is operated in the hermetic compressor 1 During this period, the flow rate of the condensed fluid flowing from the condenser 4 to the evaporator 8 can be automatically and constantly changed, the flow rate of the refrigerating fluid can be changed between the maximum value and the minimum value, and the above-mentioned flow channel can be closed when the compressor 1 is shut down . When the above-mentioned airtight compressor 1 belongs to the kind of compressor with temporary shutdown operating conditions, such compressor will shut down as the temperature of the evaporator 8 changes, and when the temperature sensor installed therein detects the temperature of the evaporator 8 Such temporary shutdown operating conditions are achieved and maintained at predetermined temperature conditions.

The valve 20 of the present invention is set so that the flow rate of the condensed refrigerant fluid flowing to the evaporator 8 is changed inversely proportional to the change of the condensation temperature of the refrigerant fluid in the condenser, so that the condensed refrigerant fluid flowing to the evaporator 8 is substantially close to It reaches the evaporator at the temperature of the rated condensing temperature, which is determined according to the optimal operating conditions of the refrigeration system, such as room temperature and optimal temperature conditions in the box.

In on/off type compressors with one or more rotational speeds and in variable speed compressors, the flow of condensing fluid to the evaporator 8 is at a minimum when the resulting condensing temperature is higher than the nominal condensing temperature. This minimum flow condition is achieved due to the pressure increase upstream of valve 20 . This pressure increase is proportional to the increase in the mass of refrigerant in the refrigeration circuit of the condenser 4 .

According to the invention, the valve 20 has a valve body 21 mounted, for example, in the evaporator 8, in which a refrigerant fluid channel 22 is formed, the cross-section of which is inversely proportional to that of the condenser during operation of the hermetic compressor 1. The condensing temperature of the refrigerant fluid in 4 is varied such that the condensed refrigerant fluid delivered to boil-off gas 8 has a temperature substantially close to the rated condensing temperature of the system.

For example, when the hermetic compressor 1 is shut down as the temperature of the evaporator 8 changes, the refrigerant fluid passage 22 is closed.

The valve body 21 also has an opening 23 which is always in fluid communication with the condensate fluid inlet 9 of the evaporator 8 .

A valve seat 24 is formed in the valve body 21, and a sealing device 25 is selectively pressed against the valve seat 24 when the hermetic compressor 1 is stopped, and the above-mentioned sealing device 25 is operatively engaged with the refrigerant fluid passage 22, so that The seal is subjected directly and simultaneously to the condensing pressure upstream of the valve 20 and the pumping pressure downstream of the valve 20 .

Variations in the cross-section of the refrigerant fluid passage 22 between the above-mentioned fully closed state of the refrigerant fluid passage 22 and various open states are due to the condensing pressure and the pump pressure acting simultaneously on the sealing device 25 during the operation of the hermetic compressor 1. The fully closed state is formed when the sealing device 25 is seated on the valve seat 24, resulting from the balance of forces between the suction pressure and the various open states corresponding to temperatures substantially close to the rated condensing temperature.

The condensing pressure is the pressure necessary to transform the refrigerant fluid into a gaseous state in the condenser 4, while the pumping pressure is the pressure obtained due to the operation of the compressor. The displacement of the sealing device 25 between the fully closed position and the various open positions of the refrigerant fluid passage 22 varies with the force formed by the condensing pressure and the pumping pressure, which causes the cross-section of the refrigerant fluid passage 22 to change. Variety. The sealing device 25 has a sealing part and a pushing part, the former is formed upstream of the valve 20 by the condensing pressure, while the latter is located downstream of the valve seat so as to easily feel the pumping pressure in this area, and the pushing part utilizes a spring member 26 Connected to the valve body 21, the spring member always pushes the sealing device 25 towards the closed state of the refrigerant fluid passage.

As illustrated, the advancing portion of the sealing means 25 is adjustably connected to the spring 26 by means of an annular connection means 29 mounted on the spring member 26 displaced against the end of the sealing means 25 of the sealing portion thereof. Inside this ring connection, the mobile seal allows continuous damping adjustment.

According to the option of the structure of the present invention, the sealing device 25 is installed in the valve 20 through the valve seat 24, so that its sealing part is arranged on the valve seat 24, and its propelling part is constantly located in the valve body 21. The shape of the sealing part The profile matches the profile of the valve seat 24 .

According to the present invention, valve body 21 forms cavity 27 inside, so that by refrigerant fluid, this cavity communicates with the condensed fluid outlet 6 of condenser 4 through valve seat 24, and through opening 23 continuously with the condensed fluid inlet of evaporator 8 9 connected. In this construction, the spring member 26 is in the form of a diaphragm forming the wall of the chamber 27 opposite the valve seat 24 through which the refrigerant fluid passes.

The operation of the hermetic compressor 1 pumping refrigerant gas results in insufficient pressure acting on the spring member 26 in the above-mentioned cavity 27 of the valve body 21, resulting in a change in the relative position between the sealing device 25 and the valve seat 24.

The refrigerant fluid passage 22 is defined by the annular space formed between the valve seat 24 and the sealing device 25 .

In the illustrated embodiment, the cross-section of the cooling fluid channel 22 also varies with the temperature of the evaporator 8 . This temperature change determines the state of contraction and expansion of the temperature-sensitive fluid contained within the valve 20 and acting on the sealing means 25, as described below.

A spring member 26 is installed in the valve body 21 so that it can constantly push the sealing device 25 to the closed state of the refrigerant fluid passage 22. According to the present invention, the spring member 26 has a sealing position and a plurality of fluid passage positions, and the sealing position is reached when the airtight compressor 1 is stopped, and when suction occurs in the cavity 27 to allow refrigerant fluid to pass through due to the elasticity of the spring member 26 Deformation allows access to the many fluid passage locations.

In the illustrated construction, the spring 26 laterally divides the valve body 21 into a chamber 27 through which the refrigerant fluid passes, and an airtight chamber 28 containing the fluid in the evaporator 8 which is susceptible to temperature changes and moves with the evaporator 8. The temperature changes in the spring force the spring member 26 to form different bending states.

A temperature-sensitive part is defined as a component whose characteristic changes in response to temperature changes in the evaporator 8, so that when the compressor 1 is not in operation, the above-mentioned temperature-sensitive fluid ensures that the spring member 26 is in the sealing position, while the compressor 1 is in operation. Meanwhile, the contraction of the temperature sensitive fluid will continuously push the spring member 26 towards its closed position when the temperature in the evaporator 8 decreases and towards its open position when the temperature in the evaporator 8 increases.

A spring member 26 housed in the valve body 21 divides said valve body 21 into substantially equal areas, namely a cavity 27 and a gas-tight cavity 28 .

The spring member 26 is fixed on the pushing portion of the sealing device 25 and the valve body 21 so that the sealing device 25 can be constantly pushed toward the fully closed position of the refrigerant fluid passage 22 during the operation of the hermetic compressor 1 . With the change of the difference between the forces acting on the above-mentioned elastic member 26, the spring member 26 can be placed in various fluid passage positions, these forces specifically include the forces caused by the condensation pressure and the pumping pressure, according to the preferred structure of the present invention operation, including forces due to temperature changes on fluids susceptible to temperature changes.

In the illustrated structure, when the pumping pressure is zero and when, for example, the temperature-sensitive fluid contracts, a force acting on the above-mentioned spring member 26 is generated, so that the spring member 26 moves away from the valve seat 24, so that the sealing device 25 is in its position. The state in which the sealing part is closed on the valve seat 24 and remains in this state when the spring member 26 reaches its sealing position until the compressor is restarted.

By correspondingly bending the above-mentioned spring member, making it close to the valve seat 24 and moving the sealing device 25 away from its sealing position relative to the valve seat 24, the spring member 26 can reach various fluid passage positions.

For on/off type compressors with constant speed or with at least two operating speeds, the operation of the compressor will generate a pumping pressure when the temperature in the evaporator 8 reaches a predetermined value at which the hermetic compressor 1 can be started , the pressure is located on the low-pressure side of the refrigeration line, acting on the advancing portion of the sealing device 25, thereby moving its sealing portion away from the valve seat 24.

During operation of the hermetic compressors 1, the suction pressure in these compressors is kept constant. In this case, the pressure acting on the above-mentioned sealing device 25 varies with the condensing temperature and condensing pressure of the condensed refrigerant fluid in the condenser 4 .

In variable speed compressors where there is an operational shutdown of the hermetic compressor 1, the low temperature in the evaporator 8 reduces the rotational speed of the compressor and the suction pressure. The change in the flow rate of the condensing fluid to the evaporator 8 is caused by the combined force of the suction pressure in the chamber 27 and the conditions of the condensation temperature and pressure of the condensing refrigerant fluid.

During operation of the compressor, a suction pressure is developed in the cavity 27 of the valve body 21 through the above-mentioned valve and the suction inlet 10 of the hermetic compressor 1 . This suction pressure acts on the spring member 26 to bend it close to the valve seat 24 of the valve body 21, thereby reducing the volume of the cavity 27 and expanding the airtight cavity 28 proportionally. The above-mentioned movement causes the sealing device 25 to move. to a position spaced apart from the valve seat 24 so that a predetermined amount of condensed refrigerant fluid flows to the evaporator 8 at a condensing temperature substantially close to the rated condensing temperature and which no longer affects the evaporating efficiency of the evaporator 8.

According to the sealing means and sealing means seat described above, the flow rate of condensing fluid flowing through the refrigerant fluid passage is proportional to the distance between the outer surface of the seat portion of the sealing means 25 and the annular surface of the valve seat 24. With variations in the operation of the hermetic compressor 1 , and thus with variations in the suction pressure present during operation of the compressor, the sealing portion of the sealing device 25 does not reach a sealing position relative to the valve seat 24 .

As the condensing temperature of the fluid pumped to the condenser increases, the pressure on the sealing portion of the seal 25 increases, causing the seal to move closer to the valve seat 24, restricting the passage of refrigerant fluid through the refrigerant fluid flow control The flow of the valve thus restricts the flow into the evaporator 8 .

The maximum pressure state of the sealing means 25 establishes the minimum flow value of the refrigerant fluid through the refrigerant fluid flow control valve. Restricting the flow of fluid to the evaporator 8 makes the volume of refrigerant gas drawn by the compressor on the low pressure side of the refrigerant line progressively smaller. This reduction in mass flow avoids overloading of the hermetic compressor 1 .

As the restriction on the flow of the refrigerant fluid to the evaporator 8 is increased, the fluid will accumulate in the condenser 4, thereby increasing the pressure and temperature therein, thereby achieving a thermal exchange between the above-mentioned fluid and the external environment of the condenser 4. The temperature of the exchange causes the aforementioned fluid to condense. This throttling is maintained until the temperature of the condensing fluid decreases, thereby reducing the pressure on the seal 25 so that it can separate from the valve seat 24 . Due to this division, the cross-section of the refrigerant fluid passage 22 gradually increases, thereby increasing the flow rate of the condensing fluid to the evaporator. During the operation of the hermetic compressor 1, pressure changes on the sealing device 25 control the flow rate of the refrigerant fluid to the evaporator 8, whereby the above-mentioned flow rate can be automatically and continuously adjusted, thereby increasing the efficiency of the condenser 4, mainly in the external environment. Reduces the load on the hermetic compressor when the temperature exceeds the rated condensing temperature.

The structural feature of the above-mentioned device is determined such that the sealing device can be separated from the valve seat 24 when the hermetic compressor 1 is restarted. The movement of the spring member 26 caused by temperature changes in the evaporator 8 during operation of the hermetic compressor 1 determines the resultant force acting on the seal.

Claims (10)

1. the refrigeration pipeline of refrigeration system configuration comprises: air-tight compressor (1); Condenser (4) has an inlet and that is connected in compressor (1) outlet and exports; Evaporimeter (8); having an inlet and that is connected in condenser (4) outlet exports; it is characterized in that; it comprises the refrigeration fluid flow control valve (20) that is contained between condenser (4) outlet and evaporimeter (8) inlet; this valve has refrigeration fluid passage (22); the cross section of this passage was inversely proportional to the variation of condensation temperature and changes in air-tight compressor (1) operating period; thereby make the condensation refrigeration fluid that is transported to evaporimeter (8) have the temperature that equals the specified condensation temperature of system substantially; between air-tight compressor (1) down period; its cross section of above-mentioned refrigeration fluid passage (22) is closed, and makes the fluid flow disruption between condenser (4) and the evaporimeter (8) fully.

2. refrigeration pipeline configuration as claimed in claim 1, it is characterized in that, above-mentioned valve (20) comprises sealing device (25), this device combines with refrigeration fluid passage (22) in operation, can be directly and be subjected to the effect of valve (20) swabbing pressure in the condensing pressure of valve (20) upstream and valve (20) downstream simultaneously, the variation of the power that above-mentioned sealing device (25) forms with above-mentioned pressure and displacement, thus the cross section that makes refrigeration fluid passage (22) changes between the state that the buttoned-up status and the refrigeration fluid of this passage reaches specified condensation temperature.

3. refrigeration pipeline configuration as claimed in claim 2 is characterized in that refrigeration fluid passage (22) are determined by the annular space between valve seat (24) and the sealing device (25).

4. refrigeration pipeline configuration as claimed in claim 3, it is characterized in that, valve (20) comprises valve body (21), form the chamber (27) of flowing through the refrigeration fluid in this valve body, this chamber is communicated with the outlet of condenser (4) by valve seat (24) and has opening (23), and this opening always communicates with the inlet fluid of evaporimeter (8).

5. refrigeration pipeline configuration as claimed in claim 4; it is characterized in that; sealing device (25) comprises hermetic unit that is positioned at valve seat (24) upstream and the propulsive units that is positioned at the valve seat downstream; above-mentioned propulsive units is connected in valve body (21) by spring part (26); this spring part is always pushed sealing device (25) to the closed condition of refrigeration fluid passage (22); above-mentioned spring part (26) has sealing station and passes through the position to the fluid that reduces a lot; this spring arrives detent position when air-tight compressor (1) is shut down, and when exist in chamber (27) aspirate so that the refrigeration fluid when flowing through this spring (26) reach these many fluids by strain and pass through the position.

6. refrigeration pipeline configuration as claimed in claim 5 is characterized in that spring members (26) is the dividing plate form, forms the wall facing to valve seat (24) in chamber (27).

7. refrigeration pipeline configuration as claimed in claim 6, it is characterized in that spring part (26) is contained in the valve body (21), valve body is divided into chamber (27) and airtight chamber (28) by the refrigeration fluid, in this airtight chamber a kind of fluid is housed, this fluid is experienced the variations in temperature of evaporimeter (8) easily.

8. refrigeration pipeline configuration as claimed in claim 7, it is characterized in that, the fluid of easily experiencing temperature acts on the spring part (26), thereby when the temperature of evaporimeter (8) reduces, push this elastic component to sealing station, pass through the position and when the temperature of evaporimeter (8) rises, push this spring part (26) to various fluids.

9. refrigeration pipeline configuration as claimed in claim 7 is characterized in that valve body (21) is airtight, is contained in the evaporimeter (8), near its condensed fluid inlet.

10. refrigeration pipeline configuration as claimed in claim 9 is characterized in that the propulsive units of sealing device (25) is connected in spring part (26) adjustablely.

Images