Liquid level control system for inlet separator of refrigeration station

Abstract

The utility model belongs to the technical field of refrigeration, and particularly discloses a refrigeration station inlet separator liquid level control system which comprises a controller, an inlet separator, an evaporation tank, a first liquid level transmitter, a shield pump and a hot air control valve, and the inlet separator, the evaporation tank, the first liquid level transmitter, the shield pump and the hot air control valve are connected with the controller. A first inlet of the inlet separator is used for inputting boil-off gas, and a first outlet of the inlet separator is connected with the compressor; a second outlet of the inlet separator is respectively connected with an inlet of the shield pump and an inlet of the evaporation tank, and the liquid level control valve is arranged between the inlet separator and the evaporation tank; a third inlet of the inlet separator is in hot air connection with an outlet of the compressor, and the hot air control valve is arranged between the third inlet and the outlet; an outlet of the evaporation tank is connected with a second inlet of the inlet separator; and the first liquid level transmitter is used for monitoring the liquid level in the inlet separator. And the liquid level in the inlet separator can be controlled, so that the loss caused by shutdown with liquid is reduced.

Description

TECHNICAL FIELD

[0001] The utility model belongs to refrigeration technical field especially relates to a refrigeration station inlet separator liquid level control system. BACKGROUND

[0002] The refrigeration station is one of important applications of modern refrigeration technology, and is widely used in various industrial, commercial and civil fields. The main function of the refrigeration station is to transfer heat from a low temperature area to a high temperature area through a refrigeration cycle system, so as to achieve the purpose of cooling or freezing. The refrigeration station has a compressor inside, and the function of the compressor is to extract refrigerant to a high pressure state. When the refrigerant is compressed, its temperature and pressure will rise significantly. During the starting and normal operation of the compressor, the hot gas coming from the separator and the gas coming from the evaporator will carry liquid droplets of refrigerant. After the liquid droplets are separated by the separator, they will be concentrated in the separator. The rising liquid level in the separator will cause the compressor to stop, and the refrigeration station will stop. If the liquid level is too high to enter the compressor, it will cause damage to the compressor impeller, resulting in huge economic losses. SUMMARY

[0003] The purpose of the utility model is to provide a refrigeration station inlet separator liquid level control system, which can control the liquid level in the separator, thereby reducing the loss caused by liquid stopping.

[0004] In order to achieve the above purpose, the technical scheme of the utility model is as follows: a refrigeration station inlet separator liquid level control system, comprising a controller and an inlet separator, an evaporating tank, a first liquid level transmitter, a shield pump and a hot gas control valve connected with the controller; the first inlet of the inlet separator is used for inputting evaporating gas, and the first outlet of the inlet separator is connected with the compressor; the second outlet of the inlet separator is respectively connected with the shield pump and the inlet of the evaporating tank, and the liquid level control valve is arranged between the inlet separator and the evaporating tank; the third inlet of the inlet separator is connected with the hot gas outlet of the compressor and the hot gas control valve is arranged between the third inlet and the hot gas outlet; the outlet of the evaporating tank is connected with the second inlet of the inlet separator; the first liquid level transmitter is used for monitoring the liquid level in the inlet separator.

[0005] Further, the fourth inlet of the inlet separator is connected with bypass hot gas.

[0006] Further, the fourth inlet of the inlet separator is connected with a mixer, the first inlet of the mixer is connected with bypass hot gas, the second inlet of the mixer is connected with cooling liquid and the temperature control valve is arranged between the second inlet and the cooling liquid, and the mixer and the temperature control valve are connected with the controller.

[0007] Further, a pressure transmitter and a temperature transmitter are connected between the first outlet of the inlet separator and the compressor, and the pressure transmitter and the temperature transmitter are connected with the controller.

[0008] Further, a second liquid level transmitter is connected in the evaporation tank and connected with the controller.

[0009] Further, the outlet of the shield pump is connected with the liquid storage tank.

[0010] Further, the first liquid level transmitter is provided with three groups.

[0011] The working principle of the technical solution is that:

[0012] To control the liquid level, only the following two methods can be adopted: one is to reduce the amount of incoming liquid, and the other is to reduce the amount of existing liquid.

[0013] To reduce the amount of incoming liquid, complete vaporization of the cooling liquid coming from the bypass temperature control valve is required, and the following two approaches are adopted: 1. Control the gas superheat degree of the inlet separator. The concept of superheat degree is that the current gas temperature is higher than the saturation temperature corresponding to the current pressure. First, set the superheat degree IT value range in the controller. The actual superheat degree IT value = the actual temperature measured by the temperature transmitter - the saturation temperature corresponding to the actual pressure measured by the pressure transmitter. Set the superheat degree IT value to 10≤IT value≤15. When the actual superheat degree IT value < 10, close the temperature control valve to reduce the liquid amount of the temperature control valve to the bypass hot gas. 2. By setting a mixer on the bypass hot gas to the inlet separator pipeline, the bypass hot gas and the cooling liquid are fully mixed and vaporized, thereby reducing the liquid droplets entering the separator.

[0014] To reduce the amount of existing liquid, the following three methods are adopted: 1. The first liquid level transmitter provided on the inlet separator is used to monitor the liquid level in real time. When 40%≥the first liquid level transmitter≥20%, open the hot gas control valve to heat and evaporate the liquid using the hot gas coming from the compressor outlet; when 60%≥the first liquid level transmitter≥40%, open the liquid level control valve to let the liquid enter the evaporation tank from the inlet separator, and use the steam coil in the evaporation tank to heat the liquid, so that the liquid is evaporated and returned to the inlet separator from the evaporation tank; when the first liquid level transmitter≥60%, open the shield pump to discharge the liquid to the liquid storage tank.

[0015] The beneficial effects of the technical solution are that the temperature control valve and the mixer are set to maximize the reduction of the liquid amount entering the separator; the shield pump, the hot gas control valve, the first liquid level transmitter, and the liquid level control valve are set to maximize the elimination of the liquid level. The technical solution can minimize the loss caused by liquid during parking. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1The utility model discloses a refrigeration station inlet separator liquid level control system's structure schematic view. DETAILED DESCRIPTION

[0017] The utility model discloses a refrigeration station inlet separator liquid level control system's structure schematic view.

[0018] The utility model discloses a refrigeration station inlet separator liquid level control system's structure schematic view.

[0019] The utility model discloses a refrigeration station inlet separator liquid level control system's structure schematic view.

[0020] The utility model discloses a refrigeration station inlet separator liquid level control system's structure schematic view. Figure 1 The utility model discloses a refrigeration station inlet separator liquid level control system's structure schematic view.

[0021] The utility model discloses a refrigeration station inlet separator liquid level control system's structure schematic view.

[0022] To control the liquid level, only two methods can be considered: one is to reduce the amount of incoming liquid, and the other is to reduce the amount of existing liquid.

[0023] To reduce the amount of incoming liquid, complete vaporization of the cooling liquid coming from the bypass temperature control valve 4 is required, which can be achieved by the following two methods: 1. Control the gas superheat degree of the inlet separator 1, the concept of superheat degree is the value that the current gas temperature is higher than the saturation temperature corresponding to the current pressure, first set the superheat degree IT value range in the controller, the actual superheat degree IT value = the actual temperature measured by the temperature transmitter 6 - the saturation temperature corresponding to the actual pressure measured by the pressure transmitter 5. Set the superheat degree IT value to 10≤IT value≤15. When the actual superheat degree IT value < 10, close the temperature control valve 4 to reduce the liquid amount of the bypass hot gas to the temperature control valve 4. 2. By setting a mixer 3 on the pipeline from the bypass hot gas to the inlet separator 1, the bypass hot gas and the cooling liquid are fully mixed and vaporized, thereby reducing the liquid droplets entering the separator.

[0024] To reduce the amount of existing liquid, the following three methods can be used: 1. Real-time monitoring of the liquid level by the first liquid level transmitter 7 set on the inlet separator 1, when 40%≥first liquid level transmitter 7≥20%, open the hot gas control valve 11 to heat and evaporate the liquid by the hot gas coming from the compressor outlet; when 60%≥first liquid level transmitter 7≥40%, open the liquid level control valve 9 to let the liquid enter the evaporating tank 2 from the inlet separator 1, and use the steam coil in the evaporating tank 2 to heat the liquid, so that the liquid is evaporated and then returned to the inlet separator 1 from the evaporating tank 2; when the first liquid level transmitter 7≥60%, open the shield pump 8 to discharge the liquid to the liquid storage tank.

[0025] The beneficial effects of the technical solution are: setting the temperature control valve 4 and the mixer 3 to minimize the amount of liquid entering the separator; setting the shield pump 8, the hot gas control valve 11, the first liquid level transmitter 7 and the liquid level control valve 9 to maximize the elimination of the liquid level. The technical solution can minimize the loss caused by liquid during shutdown.

[0026] It should be noted that in this text, relational terms such as first and second are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment.

[0027] The above-mentioned is only the embodiment of the present application, and the common knowledge of the specific structure and characteristics in the scheme is not described in detail, the ordinary skilled person in the art knows all the ordinary technical knowledge in the technical field of the present application before the application date or the priority date, can know all the prior art in the field, and has the ability to apply the conventional experimental means before the date, the ordinary skilled person in the art can improve and implement the present scheme under the enlightenment given in the present application, and some typical known structures or known methods should not become an obstacle for the ordinary skilled person in the art to implement the present application. It should be pointed out that for the skilled person in the art, without departing from the structure of the present application, a number of modifications and improvements can be made, which should also be considered as the protection scope of the present application, which will not affect the effect and practicality of the present application. The protection scope of the present application should be subject to the content of its claims, and the specific implementation mode and the like in the specification can be used to explain the content of the claims.

Claims

1. A refrigeration plant inlet separator level control system, characterized by: The controller is connected with an inlet separator (1), an evaporation tank (2), a first liquid level transmitter (7), a shield pump (8) and a hot gas control valve (11); a first inlet of the inlet separator (1) is used for inputting evaporation gas, a first outlet of the inlet separator (1) is connected with a compressor, a second outlet of the inlet separator (1) is respectively connected with the shield pump (8) and an inlet of the evaporation tank (2), a liquid level control valve (9) is arranged between the inlet separator (1) and the evaporation tank (2), a third inlet of the inlet separator (1) is connected with a hot gas outlet of the compressor and a hot gas control valve (11) is arranged between the third inlet and the hot gas outlet, an outlet of the evaporation tank (2) is connected with the second inlet of the inlet separator (1), and the first liquid level transmitter (7) is used for monitoring a liquid level in the inlet separator (1).

2. A freeze station inlet separator level control system as claimed in claim 1, wherein: A fourth inlet of the inlet separator (1) is connected with bypass hot gas.

3. A freeze station inlet separator level control system according to claim 2, wherein: A mixer (3) is connected with the fourth inlet of the inlet separator (1), a first inlet of the mixer (3) is connected with bypass hot gas, a second inlet of the mixer (3) is connected with cooling liquid and a temperature control valve (4) is arranged between the second inlet and the cooling liquid, and the mixer (3) and the temperature control valve (4) are connected with the controller.

4. A freeze station inlet separator level control system according to claim 3, wherein: A pressure transmitter (5) and a temperature transmitter (6) are connected between the first outlet of the inlet separator (1) and the compressor, and the pressure transmitter (5) and the temperature transmitter (6) are connected with the controller.

5. A freeze station inlet separator level control system as claimed in claim 1, wherein: A second liquid level transmitter (10) connected with the controller is arranged in the evaporation tank (2).

6. A freeze station inlet separator level control system as claimed in claim 1, wherein: An outlet of the shield pump (8) is connected with a liquid storage tank.

7. A freeze station inlet separator level control system as claimed in claim 1, wherein: The first liquid level transmitter (7) is provided with three groups.

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