CN114812023B - A mixed working fluid filling and regulating system - Google Patents

Abstract

The invention relates to a working medium filling system, in particular to a mixed working medium filling regulating system, which comprises a refrigerant liquid storage tank, a refrigerant system pipeline, a vacuum pump and a gas collecting tank, wherein the refrigerant liquid storage tank is connected with the refrigerant system pipeline; the refrigerant liquid storage tank is respectively communicated with the air inlet end of the vacuum pump and the refrigerant system pipeline through pipelines, and the air outlet end of the vacuum pump is communicated with the air collection tank through pipelines; the refrigerant liquid storage tank is arranged at a height higher than that of the refrigerant system pipeline; after the vacuum pump vacuumizes the refrigerant liquid storage tank, the refrigerant enters the refrigerant liquid storage tank under the action of negative pressure and then enters the refrigerant system pipeline under the action of gravity. Compared with the prior art, the refrigerant filling regulating system fills low-pressure refrigerant into the mixed refrigerant circulating pipeline by utilizing the pressure balancing method and the gravity action; can solve the problems of filling and adjusting the proportion of low-pressure refrigerant into the mixed refrigerant circulating pipeline.

Description

A mixed working fluid filling and regulating system

Technical Field

The invention relates to a working fluid filling system, in particular to a mixed working fluid filling and regulating system.

Background technique

Mixed refrigerants are usually composed of two or more refrigerants with different saturation pressures, also known as non-azeotropic mixed refrigerants. The proportion of the refrigerant components determines the efficiency and operating temperature range of the refrigeration system. The existing non-azeotropic mixed refrigerant filling method requires the precise calculation of the refrigerant ratio and then charging the system in order from low to high saturation pressure.

At present, the method of charging mixed refrigerant is to first charge low-pressure refrigerant and then high-pressure refrigerant. The mass of each refrigerant needs to be accurately measured before charging, and the low-pressure refrigerant cannot be added and adjusted after charging. For example, the invention patent with publication number CN106566476A has a mixed refrigerant with components of R142b (saturated pressure is 0.195MPa), R134a (saturated pressure is 0.401MPa), and R22 (saturated pressure is 0.661MPa). After the refrigeration system is evacuated, the required proportion of R142b liquid refrigerant is first filled, then the required proportion of liquid R134a refrigerant is filled, and finally the required proportion of liquid R22 refrigerant is filled. If there is a deviation in the calculation of the refrigerant charge amount or the refrigerant leaks, all the refrigerant should be released and refilled according to the above method to ensure that the proportions of each refrigerant remain unchanged. The charging process of this patent requires the steps of first charging low pressure and then high pressure. The low-pressure refrigerant cannot be further charged and adjusted in the later stage. Once the calculation deviation or leakage occurs, the refrigerant in the system needs to be discharged, resulting in waste of refrigerant and environmental pollution. In order to solve the above problems, a mixed working fluid charging and adjustment system is proposed.

Summary of the invention

The purpose of the present invention is to provide a mixed refrigerant filling and adjustment system in order to solve at least one of the above-mentioned problems. The height difference between the refrigerant liquid storage tank and the refrigerant system pipeline is used to fill the low-pressure refrigerant into the refrigerant system pipeline, thereby solving the problem that the low-pressure refrigerant cannot be filled and adjusted when there is a deviation in the calculation of the refrigerant filling amount or the refrigerant leaks, thereby reducing the waste of refrigerant and environmental pollution, reducing the refrigerant cost and facilitating the operation of the refrigeration system.

The purpose of the present invention is achieved through the following technical solutions:

A mixed working fluid charging and regulating system comprises a refrigerant liquid storage tank, a refrigerant system pipeline, a vacuum pump and a gas collecting tank;

The refrigerant liquid storage tank is connected to the air inlet of the vacuum pump and the refrigerant system pipeline through pipelines, and the air outlet of the vacuum pump is connected to the air collecting tank through pipelines;

The refrigerant liquid storage tank is arranged at a height higher than the refrigerant system pipeline;

After the vacuum pump evacuates the refrigerant storage tank, the refrigerant enters the refrigerant storage tank under the action of negative pressure, and then enters the refrigerant system pipeline under the action of gravity.

Preferably, the refrigerant liquid storage tank is arranged at a height 30-50 cm higher than the refrigerant system pipeline.

Preferably, the system further comprises a lifting platform, wherein the lifting platform is arranged below the refrigerant liquid storage tank and is used for adjusting the height of the refrigerant liquid storage tank.

Preferably, the system further comprises an electronic weighing scale, which is arranged below the refrigerant storage tank and is used to weigh the mass of the refrigerant in the refrigerant storage tank.

Preferably, the precision of the electronic weighing scale is 1g.

Preferably, the exhaust volume of the vacuum pump is not less than 20 L/min; the vacuuming time is at least 1 hour, until the vacuum degree in the refrigerant storage tank is ≤10 Pa.

Preferably, a manifold pressure gauge is further provided between the vacuum pump and the refrigerant storage tank, and the vacuum pump and the manifold pressure gauge, as well as the manifold pressure gauge and the refrigerant storage tank, are connected via a pressure-resistant hose.

Preferably, the vacuum measurement range of the low-pressure side of the manifold pressure gauge is 0-101kPa, the pressure measurement scale starts from 0kPa, and the range is not less than 2110kPa; the pressure measurement scale of the high-pressure side of the manifold pressure gauge starts from 0kPa, and the range is not less than 4200kPa.

Preferably, the top of the refrigerant storage tank is connected to the refrigerant system pipeline through a pipeline, and a ball valve is provided on the pipeline; by opening the ball valve to connect the top of the refrigerant storage tank with the refrigerant system pipeline, the internal pressure of the refrigerant storage tank and the refrigerant system pipeline are balanced.

Preferably, a check valve is provided on the pipeline connecting the vacuum pump and the gas collecting tank, and a ball valve and a check valve are provided in sequence on the pipeline connecting the refrigerant liquid storage tank and the refrigerant system pipeline.

Preferably, a safety valve, a temperature gauge and a pressure gauge are also provided on the top of the refrigerant liquid storage tank.

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

1. The advantages of the present invention are that, in the first step, the low-pressure refrigerant to be charged can be determined by weighing an electronic scale; in the second step, the low-pressure refrigerant is pre-charged into a refrigerant storage tank, and the refrigerant storage tank is first evacuated with a vacuum pump. After the evacuation is completed, the vacuum pump and its valve are closed, and the valves between the refrigerant storage tank and the charging tank (i.e., the storage tank storing the corresponding refrigerant and used to charge the refrigerant to the refrigerant storage tank) are opened to complete the charging of the low-pressure refrigerant; in the third step, after the charging is completed, the valve of the charging tank is closed, the refrigerant storage tank is connected to the refrigeration system, the valve between the refrigerant storage tank and the refrigeration system is opened, and the low-pressure refrigerant is charged into the mixed refrigerant system pipeline by gravity. The whole process is simple and the effect is uniform, which can greatly solve the problem that the low-pressure refrigerant cannot be added and adjusted if the calculation of the refrigerant charging amount is deviated or the refrigerant leaks, thereby reducing the waste of refrigerant and environmental pollution, reducing the cost of refrigerant and facilitating the operation of the refrigeration system.

2. A lifting platform is set at the bottom of the refrigerant storage tank, and the refrigerant storage tank can be adjusted according to the required height; a weighing electronic scale is set at the bottom of the refrigerant storage tank to accurately measure the amount of refrigerant added, which is conducive to precise control; the air pressure between the refrigerant system pipeline and the top of the refrigerant storage tank is connected, which can avoid pressure difference when injecting refrigerant into the refrigerant system pipeline, so that the refrigerant can be smoothly injected into the refrigerant system pipeline.

3. The present invention charges the refrigerant into the mixed refrigerant circulation pipeline by balancing the pressure and gravity. It can not only be used as a conventional refrigerant addition system, but also can supplement the low-pressure refrigerant when a problem with the filling amount is found, thus overcoming the problem in the prior art that mixing needs to be started from scratch once an error occurs, avoiding refrigerant waste and reducing pollution to the environment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of a regulating system of the present invention;

In the figure: 1- refrigerant storage tank; 2- refrigerant system pipeline; 3- vacuum pump; 4- gas collecting tank; 5- lifting platform; 6- weighing electronic scale; 7- manifold pressure gauge; 8- ball valve; 9- check valve; 10- safety valve; 11- temperature gauge; 12- pressure gauge.

Detailed ways

The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in Figure 1, it is a schematic diagram of the new mixed working fluid filling and regulating system of the present invention, which includes a refrigerant liquid storage tank 1, a lifting platform 5, a check valve 9, a weighing electronic scale 6, a vacuum pump 3, a gas collecting tank 4, a manifold pressure gauge 7, a ball valve 8, a safety valve 10, a thermometer 11, and a pressure gauge 12.

In the above-mentioned new mixed working fluid filling and regulating system, a weighing electronic scale 6 is provided under the low-pressure refrigerant storage tank 1. The accuracy of the electronic scale is above 1g, which can accurately weigh the required low-pressure refrigerant filling amount and can measure the mass change in real time when the refrigerant is filled into the refrigerant system pipeline 2, so as to better control the injection amount and meet the injection needs.

In the above-mentioned novel mixed working fluid filling and regulating system, a lifting platform 5 is provided under the refrigerant storage tank 1. The height of the lifting platform 5 is adjusted by a driving motor (which can be built-in to the lifting platform 5, or can be connected to an external driving motor to realize the driving of the lifting platform 5), so that the refrigerant storage tank 1 is raised or lowered to 30-50 cm higher than the mixed refrigerant system pipeline 2.

In the above-mentioned novel mixed refrigerant filling and regulating system, the mixed refrigerant system pipeline 2 is connected to the upper part of the refrigerant liquid storage tank 1 through the ball valve 8, which can balance the pressure of the refrigerant liquid storage tank 1 and the mixed refrigerant system pipeline 2.

In the above-mentioned novel mixed working medium charging and regulating system, the refrigerant is pre-charged into the refrigerant liquid storage tank 1, and the refrigerant liquid storage tank 1 is provided with a ball valve 8 connected to the refrigeration system.

In the novel mixed working fluid charging and regulating system, the refrigerant storage tank 1 is connected to the mixed refrigerant system pipeline 2 of the refrigeration system through the ball valve 8 and the check valve 9 to inject refrigerant into the refrigerant system pipeline 2.

In the above-mentioned new mixed working fluid filling and regulating system, the refrigerant liquid storage tank 1 is evacuated to the required pressure and maintained for the required time (at least 1 hour), and the system vacuum degree is ensured to be ≤10Pa. The gas evacuated by the vacuum pump 3 is discharged to the gas collecting tank 4.

In the novel mixed working fluid charging and regulating system, the ball valve 8 and the check valve 9 between the refrigerant storage tank 1 and the refrigerant system pipeline 2 are opened to allow the low-pressure refrigerant to enter the refrigerant system pipeline 2 by gravity to complete the refrigerant charging.

In the above-mentioned novel mixed working fluid charging and regulating system, the ball valve 8 and the check valve 9 are connected to the mixed refrigerant system pipeline 2 of the refrigeration system by welding or bell mouth. The refrigeration system is a self-cascade refrigeration system, and the refrigerant is a multi-component mixed refrigerant.

In order to further illustrate the novel mixed working fluid filling and regulating system, the present invention uses the following embodiment to illustrate the specific operation implementation process.

Example 1

A novel mixed working fluid charging and regulating system, see Figure 1, the refrigerant is an environmentally friendly ternary non-azeotropic high condensing temperature refrigerant, characterized in that it includes R142b (saturated pressure is 0.195MPa), R134a (saturated pressure is 0.401MPa), R22 (saturated pressure is 0.661MPa) mixed working fluid refrigerant, the sum of the mass percentage concentration of each component in the mixed refrigerant is 100%, wherein the mass percentage of R142b is 5% to 35%, the mass percentage of R134a is 1% to 10%, and the mass percentage of R22 is 60% to 90%; in this embodiment, the mass percentage of R142b is 15%, the mass percentage of R134a is 10%, and the mass percentage of R22 is 75%. Assuming that the refrigeration system lacks low-pressure refrigerant R134a and needs to be charged with R134a refrigerant, the set low-pressure R134a refrigerant charge is about 62g, and the volume of the known liquid storage tank is about 17L. The amount of low-pressure refrigerant is matched to the refrigeration system.

In this specific embodiment, a novel mixed working fluid charging and regulating system is used to charge low-pressure refrigerant into the refrigeration system. The charging method includes the following steps:

1) As shown in Figure 1, instrument inspection: Check whether the refrigerant storage tank 1, lifting platform 5, check valve 9, weighing electronic scale 6, vacuum pump 3, gas collecting tank 4, manifold pressure gauge 7, ball valve 8, safety valve 10, thermometer 11, pressure gauge 12 and other equipment and instruments are damaged and leaking. If damaged, they should be replaced in time. A lifting platform 5 is provided under the refrigerant storage tank 1 to raise or lower the refrigerant storage tank 1 to 30-50cm higher than the mixed refrigerant system pipeline 2. In this embodiment, the refrigerant storage tank 1 is controlled to be about 40cm higher than the refrigerant system pipeline 2.

2) As shown in Figure 1, evacuate the refrigerant storage tank 1: open the ball valve 8, and use a hose to connect the high-pressure side of the manifold pressure gauge 7 to the manual valve of the vacuum pump 3; close all ball valves 8 except the one on the pipeline connecting the vacuum pump 3 and the refrigerant storage tank 1, open the manual valve of the vacuum pump 3 and the manual valve on the high-pressure side of the manifold pressure gauge 7, and start the vacuum pump 3 to start the vacuum operation; the duration of the vacuum operation should be more than 1 hour, and the longer the duration, the better. Evacuate and ensure that the system vacuum degree is ≤10Pa, and the gas extracted by the vacuum pump 3 is discharged into the gas collecting tank 4; during the vacuum operation, the temperature gauge 11 and the pressure gauge 12 on the top of the refrigerant storage tank 1 should be observed at all times, and stop immediately if any abnormality is found. After the vacuum operation is completed, turn off the vacuum pump 3 and remove the pressure-resistant hose on the high-pressure side of the manifold pressure gauge 7.

3) As shown in Figure 1, charge the refrigerant into the refrigerant storage tank 1: Use a pressure-resistant hose to connect the low-pressure side of the manifold pressure gauge 7 to the refrigerant charging tank (a tank containing low-pressure R134a, used to charge low-pressure R134a into the refrigerant storage tank 1. Taking Figure 1 as an example, the charging tank is the source of the refrigerant); at this time, first evacuate the air from the hose, loosen the connection between the hose and the low-pressure side of the manifold pressure gauge 7, and open the valve of the refrigerant charging tank. At this time, a hissing sound can be heard at the loose connection between the hose and the low-pressure side of the manifold pressure gauge 7. When there is a hissing sound, When white gas appears, close the valve of the refrigerant filling tank, and use the refrigerant to evacuate the air in the pipe; after vacuuming, the refrigerant storage tank 1 has become a vacuum state. At this time, you only need to increase the opening of the low-pressure side manual valve of the manifold pressure gauge 7, open the ball valve 8, and the refrigerant will be pressed into the refrigerant storage tank 1 by itself. According to the required low-pressure refrigerant filling amount (the amount of low-pressure refrigerant matches the refrigeration system), observe the weighing electronic scale 6 under the refrigerant storage tank 1. When the filling is close to the required refrigerant amount, reduce the opening of the low-pressure side manual valve of the manifold pressure gauge 7 until it is closed. After the filling is completed, close the ball valve 8.

4) As shown in Figure 1, the low-pressure refrigerant in the refrigerant storage tank 1 enters the mixed refrigerant system pipeline 2: when the low-pressure refrigerant is filled, open the ball valve 8 to balance the pressure between the refrigerant storage tank 1 and the mixed refrigerant system pipeline 2, open the ball valve 8 and the check valve 9, and allow the low-pressure refrigerant filled into the refrigerant storage tank 1 to flow into the mixed refrigerant system pipeline 2 under the action of gravity, and the low-pressure refrigerant enters the refrigeration system to complete the operation.

The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims (9)

1. The mixed working medium filling regulating system is characterized by comprising a refrigerant liquid storage tank (1), a refrigerant system pipeline (2), a vacuum pump (3) and a gas collecting tank (4);

the refrigerant liquid storage tank (1) is respectively communicated with the air inlet end of the vacuum pump (3) and the refrigerant system pipeline (2) through pipelines, and the air outlet end of the vacuum pump (3) is communicated with the air collection tank (4) through a pipeline;

The refrigerant liquid storage tank (1) is arranged at a height higher than that of the refrigerant system pipeline (2);

After the vacuum pump (3) vacuumizes the refrigerant liquid storage tank (1), the refrigerant enters the refrigerant liquid storage tank (1) under the action of negative pressure and then enters the refrigerant system pipeline (2) under the action of gravity;

The top of the refrigerant liquid storage tank (1) is communicated with a refrigerant system pipeline (2) through a pipeline, and a ball valve (8) is arranged on the pipeline; the top of the refrigerant liquid storage tank (1) is communicated with the refrigerant system pipeline (2) by opening the ball valve (8), so that the internal pressures of the refrigerant liquid storage tank (1) and the refrigerant system pipeline (2) are balanced;

A ball valve (8) and a check valve (9) are sequentially arranged on a pipeline connecting the refrigerant liquid storage tank (1) and the refrigerant system pipeline (2);

When the low-pressure refrigerant is completely filled in the refrigerant liquid storage tank (1), the ball valve (8) is opened to balance the pressure of the refrigerant liquid storage tank (1) and the pressure of the mixed refrigerant system pipeline (2), and then the ball valve (8) and the check valve (9) are opened to enable the low-pressure refrigerant filled in the refrigerant liquid storage tank (1) to flow into the mixed refrigerant system pipeline (2) under the action of gravity, and the low-pressure refrigerant enters the refrigerating system to finish the operation.

2. A mixed working fluid filling regulating system according to claim 1, wherein the refrigerant liquid storage tank (1) is arranged at a height of 30-50cm higher than the refrigerant system pipeline (2).

3. A mixed working fluid filling regulating system according to claim 1, further comprising a lifting table (5) arranged below the refrigerant reservoir (1) for regulating the height of the refrigerant reservoir (1).

4. A mixed working fluid filling regulating system according to claim 1, further comprising a weighing electronic scale (6), wherein the weighing electronic scale (6) is arranged below the refrigerant liquid storage tank (1) and is used for weighing the mass of the refrigerant in the refrigerant liquid storage tank (1).

5. A mixed working fluid filling regulating system according to claim 4, wherein the accuracy of the weighing electronic scale (6) is 1g.

6. The mixed working medium filling regulating system according to claim 1, wherein the exhaust amount of the vacuum pump (3) is not lower than 20L/min; the vacuumizing time is at least 1h, and the vacuum degree in the refrigerant liquid storage tank (1) is less than or equal to 10Pa.

7. The mixed working medium filling regulating system according to claim 1, wherein a manifold pressure gauge (7) is further arranged between the vacuum pump (3) and the refrigerant liquid storage tank (1), and the vacuum pump (3) and the manifold pressure gauge (7) and the refrigerant liquid storage tank (1) are connected through pressure hoses.

8. The mixed working medium filling regulating system according to claim 7, wherein the vacuum degree measuring range of the low pressure side of the manifold pressure gauge (7) is 0-101kPa, the pressure measuring scale is started from 0kPa, and the measuring range is not lower than 2110kPa; the pressure measurement scale of the high pressure side of the manifold pressure gauge (7) is started from 0kPa, and the measuring range is not lower than 4200kPa.

9. A mixed working fluid filling regulating system according to claim 1, characterized in that a check valve (9) is arranged on the pipeline connecting the vacuum pump (3) and the gas collection tank (4).