Novel low-temperature refrigerating system based on drainage valve control

Abstract

The invention discloses a novel low-temperature refrigerating system based on drainage valve control, and belongs to the field of low-temperature refrigerating technology application, the novel low-temperature refrigerating system comprises a compressor, a condenser, a drainage valve, a needle valve and an evaporator, and the system is different from the scheme that throttling expansion is conducted through an expansion valve or a capillary tube structure in traditional refrigerating. Liquid draining valve equipment is adopted between the condenser and the evaporator to control the flowing characteristics of refrigerants, the liquid refrigerants are conducted and conveyed into the evaporator to be vaporized and absorb heat, the gaseous refrigerants are blocked in the condenser to be condensed, and enough liquid-phase refrigerants are always in the evaporator to be vaporized in a phase change mode. Compared with a traditional refrigeration method, the scheme can avoid the problem that in the throttling expansion process, due to the fact that the opening degree of an expansion device is too small, the flow of refrigerants in the evaporator is insufficient, liquid refrigerants in the evaporator are directly sucked through an inlet of the compressor, and a sufficient low-temperature negative-pressure working state is formed; the lower refrigerating temperature can be achieved while it is guaranteed that the refrigerant flow and the refrigerating capacity are sufficient.

Description

Technical Field

[0001] The invention belongs to the field of low-temperature refrigeration technology application, and in particular relates to a novel low-temperature refrigeration system based on drain valve control. Background Art

[0002] The refrigeration cycle is a process of cooling and cooling by repeatedly compressing, condensing, expanding, evaporating and absorbing heat in a closed refrigeration system. The heat energy is transferred from a low-temperature object to a high-temperature object by consuming a certain amount of electrical energy. The most commonly used refrigeration method is the compressed steam refrigeration cycle. In traditional refrigeration applications, the lowest effective refrigeration temperature that can be achieved by single-stage steam compression is usually above -40℃ (233K). If you want to achieve a lower refrigeration temperature, such as in low-temperature cold storage, gas liquefaction and other occasions, the refrigerant needs to reach a lower evaporation pressure. The expansion process of the traditional refrigeration cycle requires the expansion and decompression of high-pressure refrigerant through a throttling expansion valve or a capillary structure. During the decompression process, a large amount of refrigerant kinetic energy will be converted into frictional heat and dissipated into the environment, causing additional energy efficiency loss. At the same time, in order to achieve lower refrigeration temperature and pressure, its opening needs to be reduced to a lower level. The biggest problem is that it leads to a small refrigerant flow, poor heat exchange effect in the evaporator, and insufficient cooling capacity output.

[0003] The steam trap is also called a steam trap, automatic drain or condensate drain. It is often used at the end of a steam-heated pipeline. It can continuously discharge the condensed water in the pipeline and prevent the gas in the pipe from being discharged. It has the working property of "passing liquid and blocking gas". Since it is necessary to ensure that there is sufficient refrigerant flow in the evaporator in the refrigeration cycle, and at the same time, it is necessary to take into account the needs of low-temperature refrigeration, it is possible to consider using the steam trap in the working cycle of the refrigerant, called a liquid trap, to transport the liquid refrigerant in the condenser to the evaporator in time to ensure that there is sufficient evaporation in the evaporator. At the same time, it prevents the gaseous refrigerant from flowing out and forces it to continue condensing. The compressor realizes the continuous reduction of the temperature and pressure in the evaporator through its own suction action, and realizes continuous and stable low-temperature refrigeration. It has sufficient innovation and application prospects. Summary of the invention

[0004] In view of this, the present invention proposes a novel low-temperature refrigeration system based on drain valve control, and its specific technical solution is as follows:

[0005] A novel low-temperature refrigeration system based on drain valve control is composed of a compressor, a condenser, a drain valve, a needle valve, an evaporator, etc. The compressor outlet is connected to the condenser inlet, the condenser outlet is connected to the drain valve inlet, the drain valve liquid outlet is connected to the evaporator refrigerant inlet, the drain valve gas outlet is connected to the needle valve inlet, the needle valve outlet is connected to the evaporator refrigerant inlet, and the evaporator refrigerant outlet is connected to the compressor inlet.

[0006] The trap valve has one inlet and two outlets. The inlet is located in the middle of the valve body, and both gas and liquid phase refrigerants can flow in. The gas outlet is located at the top of the valve body and is connected to the evaporator through a needle valve. The liquid outlet is located at the bottom of the valve body and is below the liquid level in the valve during normal operation. The trap valve identifies the liquid level in the valve through the position of the mechanical float. When the liquid level is higher than the set value, the float floats up and the drainage outlet is connected to discharge the refrigerant in time. When the liquid level does not reach the set position, the float falls, keeping the drainage flow path closed, forcing the excess gaseous refrigerant to continue cooling and liquefying in the condenser.

[0007] Another object of the present invention is to provide a method for using the above system, the main working process of which includes:

[0008] During the refrigeration process, the high-temperature and high-pressure refrigerant output by the compressor is input into the condenser for cooling and liquefaction, and then the refrigerant is input into the drain valve. The drain valve is initially closed, and the liquid accumulates in the valve, and the liquid level gradually rises. When the liquid level reaches the start position of the drain valve, the drain outlet in the drain valve is connected, and the remaining liquid refrigerant is discharged into the evaporator in time. After the liquid level drops back, the drain valve is closed again. The liquid refrigerant input into the evaporator is forced to expand, vaporize, evaporate and absorb heat under the suction action of the compressor, and the temperature and pressure are significantly reduced. The input air is cooled by heat exchange, and the vaporized refrigerant is input into the compressor again to complete a refrigeration cycle.

[0009] Furthermore, in the present invention, a bypass refrigerant flow path is provided between the gas outlet on the upper part of the drain valve and the inlet of the evaporator, and the opening of the flow path can be adjusted by a needle valve. At the beginning of the system, if there is no liquid in the drain valve, it will not be able to conduct and the cycle cannot be started. At this time, part of the gas can be discharged into the evaporator through the bypass flow path to adjust the initial gas pressure in the valve body, so that the refrigeration cycle can start to operate normally.

[0010] Furthermore, in addition to the mechanical float type, the drain valve of the present invention can also use various types such as thermostatic type and thermodynamic type, all of which can achieve the working effect of draining liquid and blocking gas after the condenser.

[0011] Furthermore, the present invention can be applied to the refrigeration needs of various gases and liquid working media including air.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] The present invention applies the traditional liquid trap to the compression steam refrigeration cycle, replacing the traditional throttling expansion valve and capillary tube, reasonably adjusting the gas-liquid component relationship of the refrigerant between the condenser and the evaporator, and utilizing the working property of the liquid trap of "passing liquid and blocking gas" to directly transport the liquid refrigerant in the condenser to the evaporator without throttling, and the uncondensed gaseous refrigerant is blocked in the condenser and continues to liquefy, so that a sufficient amount of liquid refrigerant is maintained in the evaporator, and then the suction action of the compressor forces it to vaporize and expand in the evaporator, forming a low-pressure or negative-pressure evaporation state. Under this working state, it can make up for the problem of insufficient refrigerant flow caused by too small an opening of the traditional throttling expansion at low evaporation temperature, and at the same time can achieve a lower refrigeration temperature and a larger refrigeration capacity, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0015] Figure 1 This is a schematic diagram of a novel low-temperature refrigeration system based on drain valve control proposed by the present invention;

[0016] Figure 2 A schematic diagram of the structure of a drain valve in a novel low-temperature refrigeration system based on drain valve control proposed by the present invention;

[0017] Reference numerals:

[0018] 1- compressor, 2- condenser, 3- drain valve, 4- needle valve, 5- evaporator, 6- input air, 3a- drain valve inlet, 3b- exhaust outlet, 3c- float, 3d- drain outlet. DETAILED DESCRIPTION

[0019] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0020] In the description of the present invention, it is necessary to understand that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0022] The principle of the drain valve used in the present invention refers to the structure of the drain valve used to discharge condensed water in the pipeline in the industrial system. The target effect achieved is to intermittently discharge the liquid refrigerant generated in the condenser into the evaporator, maintain sufficient refrigerant flow in the evaporator, and form low-pressure evaporation conditions through suction by the compressor. The drain valve can use mechanical, thermostatic or thermodynamic control methods according to different drainage conditions. In the present invention, a mechanical drain valve type is used as an example to introduce an embodiment.

[0023] Example: Figure 1 As shown, a novel low-temperature refrigeration system based on drain valve control proposed in this embodiment consists of a compressor 1, a condenser 2, a drain valve 3, a needle valve 4, an evaporator 5, etc.; wherein, the outlet of the compressor 1 is connected to the inlet of the condenser 2, the outlet of the condenser 2 is connected to the inlet of the drain valve 3, the liquid outlet of the drain valve 3 is connected to the refrigerant inlet of the evaporator 5, the gas outlet of the drain valve 3 is connected to the inlet of the needle valve 4, the outlet of the needle valve 4 is connected to the refrigerant inlet of the evaporator 5, and the refrigerant outlet of the evaporator 5 is connected to the inlet of the compressor 1.

[0024] like Figure 2 As shown, the drain valve 3 has one inlet and two outlets, wherein 3a-the inlet height is located in the middle of the valve body, and both gas and liquid phase refrigerants can flow in; 3b-the gas outlet is located at the upper part of the valve body, and is connected to the evaporator 5 through the needle valve 4; 3d-the liquid outlet is located at the bottom of the valve body, and is located below the liquid level in the valve during normal operation. The drain valve 3 identifies the position of the liquid level in the valve through 3c-the mechanical float position. When the liquid level is higher than the set value, the float floats up, the liquid discharge outlet is connected, and the refrigerant is discharged in time. When the liquid level does not reach the set position, the float falls, so that the liquid discharge flow path remains closed, forcing the excess gaseous refrigerant to continue to cool and liquefy in the condenser 2.

[0025] During the refrigeration process of the system, the high-temperature and high-pressure refrigerant output by the compressor 1 is input into the condenser 2 for cooling and liquefaction, and then the refrigerant is input into the drain valve 3. The drain valve 3 is initially closed, the liquid accumulates in the valve, and the liquid level gradually rises. When the liquid level reaches the start position of the drain valve 3, the drain outlet 3d in the drain valve 3 is opened, and the remaining liquid refrigerant is discharged into the evaporator 5 in time. After the liquid level drops back, the drain valve 3 is closed again. The liquid refrigerant input into the evaporator 5 is forced to expand, vaporize, and absorb heat under the suction action of the compressor 1. The temperature and pressure are significantly reduced, and the heat exchange refrigeration is carried out on the working medium 6-air to be cooled input on the hot side. The vaporized refrigerant is input into the compressor 1 again to complete a refrigeration cycle. Taking R22 as the refrigerant and air as the refrigerant as an example, the test is carried out. The lowest refrigeration temperature that can be achieved by the experimental system can reach -50℃, which is better than the traditional throttling expansion refrigeration.

[0026] In the embodiment of the present invention, a bypass refrigerant flow path is provided between the outlet 3b at the upper part of the drain valve 3 and the inlet of the evaporator 5, and the opening of the flow path can be adjusted by the needle valve 4. The needle valve can be of various types, including but not limited to a screw type and an electric type, and is adjusted according to the flow of the refrigerant in the cycle. If there is no liquid in the drain valve 3 at the beginning of the system, the drain valve will not be able to conduct and the cycle cannot be started. At this time, the needle valve opening can be controlled to release part of the gas into the evaporator 5 and adjust the initial gas pressure in the valve body so that the refrigeration cycle can start to operate normally.

[0027] In the embodiment of the present invention, the drain valve 3 is introduced by taking the mechanical float type as an example. In addition, the drain valve can also be used in various types such as but not limited to the thermostatic type and the thermodynamic type, and can achieve the working effect of draining and blocking gas after the condenser, and can be selected in combination with specific applications in actual work. It should be added that the parameters such as the liquid storage capacity, drain level, and external pipe diameter of the drain valve need to be designed in combination with actual work needs, and provide sufficient cooling capacity and flow while ensuring the safety and stability of the system.

[0028] In the embodiment of the present invention, the refrigerant type can be flexibly selected according to the actual refrigeration temperature range.

[0029] In the embodiment of the present invention, the pipelines involved have good pressure resistance and thermal insulation performance and can withstand long-term work under high pressure and low and high temperature conditions. The specific working pressure and temperature range need to be set according to the working needs of the refrigerant used.

[0030] The embodiments of the present invention are applicable to the refrigeration requirements of various gases and liquid working media including air.

[0031] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0032] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A new low-temperature refrigeration system based on solenoid valve liquid level control, including a condenser, a compressor and an evaporator, characterized in that: The system also has: A drain valve, wherein the condenser outlet is connected to the drain valve inlet, and the drain valve liquid outlet is connected to the evaporator refrigerant inlet; Needle valve, the gas outlet of the drain valve is connected to the needle valve inlet, and the needle valve outlet is connected to the evaporator refrigerant inlet liquid level.

2. A novel low-temperature refrigeration system based on solenoid valve liquid level control according to claim 1, characterized in that: The liquid drain valve device is provided with an inlet and two outlets, wherein the inlet height is located in the middle of the valve body, and both gas- and liquid-phase refrigerants can flow in; the gas outlet is located at the upper part of the valve body and is connected to the evaporator through a needle valve; the liquid outlet is located at the bottom of the valve body and is below the liquid level in the valve during normal operation.

3. A novel low-temperature refrigeration system based on solenoid valve liquid level control according to claim 2, characterized in that: The drain valve identifies the liquid level status in the valve through the position of a mechanical float. When the liquid level is higher than a set value, the float rises and the drainage outlet is connected to discharge the refrigerant in time. When the liquid level does not reach the set position, the float falls to keep the drainage flow path closed.

4. A novel low-temperature refrigeration system based on solenoid valve liquid level control according to claim 2, characterized in that: The two outlets of the drain valve are respectively a gas outlet and a liquid outlet, the needle valve connects the gas outlet of the drain valve and the evaporator, the refrigerant inlet of the evaporator is connected to the liquid outlet of the drain valve, and the refrigerant outlet is connected to the inlet of the compressor.

5. A novel low-temperature refrigeration system based on solenoid valve liquid level control according to claim 3, characterized in that: The system operation steps are as follows: The high-temperature and high-pressure refrigerant output by the compressor is cooled and liquefied by the condenser; The refrigerant flows into the drain valve and accumulates in the drain valve; When the liquid level reaches the drain valve start position, the drain outlet of the drain valve is opened to discharge liquid refrigerant to the evaporator. When the liquid level drops, the drain is closed again. In the evaporator, the liquid refrigerant is sucked by the compressor, forced to expand and vaporize, forming a low-pressure or negative-pressure evaporation state; The evaporator cools the working medium through heat exchange refrigeration. The vaporized refrigerant enters the compressor again, completing a refrigeration cycle.

6. A novel low-temperature refrigeration system based on solenoid valve liquid level control according to claim 1, characterized in that: The drain valve is a mechanical float type, a thermostatic type or a thermodynamic type.

7. A novel low-temperature refrigeration system based on solenoid valve liquid level control according to claim 1, characterized in that: The liquid level setting position is adjusted according to the system power and the refrigerant filling amount.

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