Liquid ring pump system capable of preventing freezing, high temperature and crystallization and control method thereof

Abstract

The present invention provides a liquid ring pump system and a control method thereof that can prevent freezing, high temperature and crystallization, which includes a liquid ring pump, a steam-water separator, a liquid level sensor, a liquid discharge electric control valve, a heat exchanger, a first electric heater, a control module, a first temperature sensor, a second temperature sensor, a liquid replenishment electric control valve, an air intake pipeline, an exhaust pipeline, a water intake pipeline, a reflux pipeline, and a liquid discharge pipeline; the air intake pipeline is connected to the liquid ring pump and the steam-water separator, the water intake pipeline is connected to the liquid ring pump, the reflux pipeline is connected to the water intake pipeline via the heat exchanger, and the exhaust pipeline and the liquid discharge pipeline connect the steam-water separator to the outside of the system; the control module is respectively connected to the liquid level sensor, the liquid discharge electric control valve, the first temperature sensor, the second temperature sensor, and the liquid replenishment electric control valve. The present invention can prevent the working fluid from freezing or crystallizing in a low temperature environment, and can quickly cool down when the working fluid temperature is too high, thereby ensuring that the liquid ring pump system works normally under different working conditions.

Description

Technical Field

[0001] The invention belongs to the technical field of liquid ring pump application systems, and in particular relates to a liquid ring pump system capable of preventing freezing, high temperature and crystallization, and a control method thereof. Background Art

[0002] When the liquid ring pump system works under the condition of the ambient temperature below zero degrees Celsius, if water is used as the working fluid, then when the liquid ring pump stops, the working fluid is very likely to freeze, causing the liquid ring pump system to not work properly. In addition, the working fluid temperature may be too high during the operation of the liquid ring pump system, and the high working fluid temperature will also affect the normal operation of the liquid ring pump system and even damage the liquid ring pump.

[0003] It is particularly noteworthy that if the gas or working fluid sucked by the liquid ring pump contains phenol and tert-butyl alcohol, which are easy to produce crystals at room temperature, then crystals will also be produced during the circulation of the working fluid. Crystals will affect the normal operation of the liquid ring pump system and even cause serious failures of the liquid ring pump system.

[0004] In order to effectively suppress the damage caused by crystals to the liquid ring pump system, the applicant has developed a crystal trap (see the utility model patent specification with the authorization announcement number CN202143789U). As an auxiliary device of the liquid ring pump system, the crystal trap effectively avoids the damage caused by crystals to the liquid ring pump system during the circulation of the working fluid by capturing or intercepting the crystals generated when the liquid ring pump system is working. However, the crystal trap cannot solve the problem of freezing of the working fluid or the working fluid temperature being too high.

[0005] It should also be noted that, as far as preventing the working fluid from freezing is concerned, the prior art also provides some technical means, such as the technical means disclosed in the invention patent application No. CN114576209A. However, the prior art does not provide a technical means that has comprehensive functions of antifreeze (preventing the working fluid from freezing), high temperature protection (preventing the working fluid from being abnormally high in temperature) and preventing the working fluid from producing crystals. In addition, simply applying the prior art described in patent documents such as the utility model patent specification of CN202143789U and the invention patent application specification of CN114576209A to the liquid ring pump system will also lead to an increase in the manufacturing cost, use cost and maintenance cost of the liquid ring pump system.

[0006] In short, how to effectively prevent the working fluid of the liquid ring pump system from freezing or crystallizing in a low temperature environment, and effectively prevent the working fluid from reaching abnormally high temperatures during operation, is a technical problem that needs to be solved urgently in this field. Summary of the invention

[0007] The purpose of the present invention is to effectively solve the problem of working fluid freezing or crystallization faced by the liquid ring pump system when working in a low temperature environment with lower manufacturing cost, use cost and maintenance cost, and effectively prevent the working fluid from reaching abnormally high temperature during operation, thereby overcoming the defects of the above-mentioned prior art.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A liquid ring pump system capable of preventing freezing, high temperature and crystallization, comprising a liquid ring pump, a steam-water separator, a liquid level sensor, a liquid discharge electric control valve, a heat exchanger, a first electric heater, a control module, a first temperature sensor, a second temperature sensor, a liquid replenishment electric control valve, an air intake pipeline, an exhaust pipeline, a water intake pipeline, a reflux pipeline, and a liquid discharge pipeline;

[0010] The air inlet pipeline is divided into two sections, the front section connects the outside of the system with the air inlet of the liquid ring pump, the first electric heater is arranged on one side of the front section of the air inlet pipeline, and the rear section connects the exhaust port of the liquid ring pump with the air inlet at the top of the steam-water separator. The top of the steam-water separator is also provided with an exhaust port, and the exhaust pipeline connects the exhaust port of the steam-water separator with the outside of the system;

[0011] The liquid level sensor is arranged on one side of the steam-water separator and is electrically connected to the steam-water separator; a drain port is arranged at the bottom or the lower part of the side of the steam-water separator, a drain pipe connects the drain port of the steam-water separator with the outside of the system, and a drain electric control valve is arranged on the drain pipe; a reflux port is also arranged at the bottom or the lower part of the side of the steam-water separator, and a reflux pipe connects the reflux port of the steam-water separator with the heat exchanger; the heat exchanger is connected with the water inlet pipe;

[0012] The water inlet pipeline connects the water source outside the system and the return water after heat exchange in the heat exchanger to the liquid ring pump. The liquid replenishment electric control valve is arranged on the water inlet pipeline on one side of the heat exchanger. The second temperature sensor is arranged on one side of the liquid replenishment electric control valve and connected to the pipe wall of the water inlet pipeline.

[0013] The control module is respectively connected to the liquid level sensor, the liquid discharge electric control valve, the first temperature sensor, the second temperature sensor, and the liquid replenishment electric control valve for communication.

[0014] On the basis of the above technical solution, the present invention can add the following technical means to better achieve the purpose of the present invention:

[0015] It also includes a second electric heater, which is arranged on one side of the liquid ring pump.

[0016] Furthermore, it also includes a third electric heater, which is arranged on one side of the return pipeline.

[0017] The above technical solution constitutes the product part of the present invention. With the above technical solution as the material and technical means, the present invention further provides a control method for a liquid ring pump system that can prevent freezing, high temperature and crystallization, which includes the following steps:

[0018] Step 1, when the liquid ring pump system is working normally, the sucked gas is discharged into the steam-water separator with the working fluid, the separated gas is discharged outside the system, the separated working fluid enters the heat exchanger through the reflux pipeline for cooling, and then flows back to the liquid ring pump through the water supply pipeline for recycling. The function of the heat exchanger is to take away the compression heat generated when the liquid ring pump is working normally, so as to ensure that the working fluid temperature of the liquid ring pump system can be maintained stable; the second temperature sensor monitors the working fluid temperature Ta at the water inlet of the liquid ring pump, and transmits the temperature signal to the control module;

[0019] Step 2, the control module determines the temperature. If Ta≤Tmin, (Tmin is the lowest allowable temperature close to the freezing or crystallization temperature of the working fluid, usually 5-8°C higher than the freezing or crystallization temperature of the working fluid), the first electric heater is started to heat and increase the temperature of the working fluid. At the same time, the second and third electric heaters are started to heat, which can accelerate the temperature increase in the entire system and ensure that no crystallization will occur in the suction and exhaust flow channels of the liquid ring pump system; if Ta≥Tmax (Tmax is the highest allowable temperature of the working fluid, which is calculated when the liquid ring pump is selected), it means that the working fluid temperature is too high, which may affect the performance of the liquid ring pump. At this time, the liquid replenishment electric control valve can be opened to replenish new working fluid with a lower temperature, thereby quickly reducing the working fluid temperature;

[0020] Step 3: If the liquid level of the steam-water separator exceeds the normal value due to the addition of new working fluid, the liquid level sensor will transmit the liquid level signal to the control module, and the control module will control the drain electric control valve to open and discharge part of the working fluid until the liquid level returns to normal;

[0021] Step 4, the first temperature sensor monitors the reflux water temperature Tb of the steam-water separator 2. By comparing the difference between Tb and Ta (usually Tb-Ta=5~10°C), it can be determined whether the heat exchanger 5 or the second temperature sensor is faulty, and then the control module issues a fault alarm.

[0022] Compared with the prior art, the main beneficial effects of the present invention are as follows:

[0023] Through the coordinated work of various components in the system, the present invention can effectively control the working fluid temperature and the suction and exhaust temperature of the liquid ring pump within a reasonable range under low temperature conditions, thereby effectively avoiding ice or crystallization in the system, and also preventing the working fluid temperature from being too high and affecting the normal operation of the liquid ring pump. In particular, in the present invention, the liquid replenishment electric control valve is arranged on the water inlet pipeline of the liquid ring pump on one side of the heat exchanger, and is not arranged on the steam-water separator like other conventional liquid ring pump systems. This structural design enables the present invention to quickly reduce the working fluid temperature in the liquid ring pump through fresh working fluid at a relatively low temperature. In addition, it also avoids the mixing of fresh working fluid with the old working fluid in the steam-water separator (the discharge electric control valve discharges the old working fluid), and can greatly reduce the various damages caused by the crystals formed by the soluble components dissolved in the suction gas during the circulation of the working fluid of the liquid ring pump. In short, the present invention can not only avoid the freezing or crystallization of the working fluid under low temperature conditions, but also quickly cool down the working fluid when the temperature is too high, thereby ensuring the normal operation of the liquid ring pump system under different working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic structural diagram of an embodiment of the present invention;

[0025] In the figure:

[0026] 1——Liquid ring pump; 2——Steam-water separator;

[0027] 3——Liquid level sensor; 4——Electronic drain valve;

[0028] 5——heat exchanger; 601——first electric heater;

[0029] 602——the second electric heater; 603——the third electric heater;

[0030] 7——control module; 801——first temperature sensor;

[0031] 802——second temperature sensor; 9——liquid replenishment electronic control valve;

[0032] 10——intake pipe; 11——exhaust pipe;

[0033] 12——water inlet pipe; 13——return pipe;

[0034] 14——Drainage line. DETAILED DESCRIPTION

[0035] In order to facilitate those skilled in the art to more fully understand the technical solution and working principle of the present invention, an embodiment of the present invention is described below in conjunction with the accompanying drawings:

[0036] A liquid ring pump system capable of preventing freezing, high temperature and crystallization, comprising a liquid ring pump 1, a steam-water separator 2, a liquid level sensor 3, a liquid discharge electric control valve 4, a heat exchanger 5, a first electric heater 601, a second electric heater 602, a third electric heater 603, a control module 7, a first temperature sensor 801, a second temperature sensor 802, a liquid replenishment electric control valve 9, an air intake pipeline 10, an exhaust pipeline 11, a water intake pipeline 12, a reflux pipeline 13, and a liquid discharge pipeline 14;

[0037] The air inlet pipeline 10 is divided into two sections, the front section connects the outside of the system with the air inlet of the liquid ring pump 1, and the rear section connects the exhaust port of the liquid ring pump 1 with the air inlet at the top of the steam-water separator 2. The top of the steam-water separator is provided with an exhaust port, and the exhaust pipeline 11 connects the exhaust port of the steam-water separator 2 with the outside of the system;

[0038] The liquid level sensor 3 is arranged on one side of the steam-water separator 2 and is electrically connected to the steam-water separator 2; a liquid discharge port is arranged at the lower part of the side of the steam-water separator 2 (the liquid discharge port can also be arranged at the bottom of the steam-water separator 2), a liquid discharge pipeline 14 connects the liquid discharge port of the steam-water separator 2 with the outside of the system, and a liquid discharge electric control valve 4 is arranged on the liquid discharge pipeline 14; a reflux port is also arranged at the bottom of the steam-water separator 2 (the reflux port can also be arranged at the lower part of the side of the steam-water separator 2), and a reflux pipeline 13 connects the reflux port of the steam-water separator 2 with the heat exchanger 5; the heat exchanger 5 is connected with the water inlet pipeline 12 (that is, the reflux pipeline 13 is connected with the water inlet pipeline 12 through the heat exchanger 5);

[0039] The first electric heater 601 is arranged at one side of the front section of the air inlet pipeline 10, the second electric heater 602 is arranged at one side of the liquid ring pump 1, and the third electric heater 603 is arranged at one side of the return pipeline 13; the first temperature sensor 801 is arranged at one side of the third electric heater 603 and connected to the pipe wall of the return pipeline 13;

[0040] The water inlet pipeline 12 connects the water source outside the system and the return water after heat exchange in the heat exchanger 5 with the liquid ring pump 1. The liquid replenishment electric control valve 9 is arranged on the water inlet pipeline 12 on one side of the heat exchanger 5. The second temperature sensor 802 is arranged on one side of the liquid replenishment electric control valve 9 and connected to the pipe wall of the water inlet pipeline 12.

[0041] The control module 7 is communicatively connected with the liquid level sensor 3 , the drain electric control valve 4 , the first electric heater 601 , the second electric heater 602 , the third electric heater 603 , the first temperature sensor 801 , the second temperature sensor 802 , and the replenishment electric control valve 9 .

[0042] It should be noted that in this embodiment, three electric heaters are provided, namely, the first electric heater 601, the second electric heater 602, and the third electric heater 603. In the actual implementation of the present invention, only the first electric heater 601 may be provided according to actual needs.

[0043] The structural features of an embodiment of the present invention are described above in conjunction with the accompanying drawings. The control method thereof is further described below, and includes the following steps:

[0044] Step 1, when the liquid ring pump system is working normally, the sucked gas is discharged into the steam-water separator 2 with the working fluid, the separated gas is discharged outside the system, the separated working fluid enters the heat exchanger 5 through the reflux pipeline 13 for cooling, and then flows back to the liquid ring pump 1 through the water inlet pipeline 12 for recycling. The function of the heat exchanger 5 is to take away the compression heat generated when the liquid ring pump 1 is working normally, so as to ensure that the working fluid temperature of the liquid ring pump system can be maintained stable; the second temperature sensor 802 monitors the working fluid temperature Ta at the water inlet of the liquid ring pump 1, and transmits the temperature signal to the control module 7;

[0045] Step 2, the control module 7 determines the temperature situation. If Ta≤Tmin, (Tmin is the lowest allowable temperature close to the freezing or crystallization temperature of the working fluid, usually 5-8°C higher than the freezing or crystallization temperature of the working fluid), the first electric heater 601 is started for heating to increase the temperature of the working fluid, and the second and third electric heaters 602 and 603 are started for heating at the same time, which can accelerate the temperature increase in the entire system and ensure that no crystallization occurs in the suction and exhaust flow channels of the liquid ring pump system; if Ta≥Tmax (Tmax is the highest allowable temperature of the working fluid, which is obtained by calculation when the liquid ring pump is selected, and the specific calculation method belongs to the existing technical means in the prior art; in short, the specific values ​​of Tmin and Tmax are determined according to the specific model and specifications of the liquid ring pump), it means that the working fluid temperature is too high, which may affect the performance of the liquid ring pump. At this time, the liquid replenishment electric control valve 9 can be opened to replenish new working fluid with a lower temperature, thereby quickly reducing the working fluid temperature;

[0046] Step 3, if the liquid level of the steam-water separator 2 exceeds the normal value due to the addition of new working fluid, the liquid level sensor 3 will transmit the liquid level signal to the control module 7, and the control module 7 will control the drain electric control valve 4 to open and discharge part of the working fluid until the liquid level returns to normal;

[0047] Step 4, the first temperature sensor 801 monitors the reflux water temperature Tb of the steam-water separator 2. By comparing the difference between Tb and Ta (usually Tb-Ta=5~10°C), it can be determined whether the heat exchanger 5 or the second temperature sensor 802 is faulty, and then the control module 7 issues a fault alarm.

Claims

1. A liquid ring pump system that can prevent freezing, high temperature and crystallization, Features: It includes a liquid ring pump, a steam-water separator, a liquid level sensor, a liquid discharge electric control valve, a heat exchanger, a first electric heater, a control module, a first temperature sensor, a second temperature sensor, a liquid replenishment electric control valve, an air intake pipeline, an exhaust pipeline, a water intake pipeline, a reflux pipeline, and a liquid discharge pipeline; The air inlet pipeline is divided into two sections, the front section connects the outside of the system with the air inlet of the liquid ring pump, the first electric heater is arranged on one side of the front section of the air inlet pipeline, and the rear section connects the exhaust port of the liquid ring pump with the air inlet at the top of the steam-water separator. The top of the steam-water separator is also provided with an exhaust port, and the exhaust pipeline connects the exhaust port of the steam-water separator with the outside of the system; The liquid level sensor is arranged on one side of the steam-water separator and is electrically connected to the steam-water separator; a drain port is arranged at the bottom or the lower part of the side of the steam-water separator, a drain pipe connects the drain port of the steam-water separator with the outside of the system, and a drain electric control valve is arranged on the drain pipe; a reflux port is also arranged at the bottom or the lower part of the side of the steam-water separator, and a reflux pipe connects the reflux port of the steam-water separator with the heat exchanger; the heat exchanger is connected with the water inlet pipe; The water inlet pipeline connects the water source outside the system and the return water after heat exchange in the heat exchanger to the liquid ring pump. The liquid replenishment electric control valve is arranged on the water inlet pipeline on one side of the heat exchanger. The second temperature sensor is arranged on one side of the liquid replenishment electric control valve and connected to the pipe wall of the water inlet pipeline. The control module is respectively connected to the liquid level sensor, the liquid discharge electric control valve, the first temperature sensor, the second temperature sensor, and the liquid replenishment electric control valve for communication; It also includes a second electric heater, which is arranged on one side of the liquid ring pump, and a third electric heater, which is arranged on one side of the return pipeline.

2. A control method for a liquid ring pump system capable of preventing freezing, high temperature and crystallization as claimed in claim 1, comprising the following steps: Step 1, when the liquid ring pump system works normally, the sucked gas carries the working fluid and is discharged into the steam-water separator, the separated gas is discharged out of the system, the separated working fluid enters the heat exchanger through the reflux pipeline for cooling, and then flows back to the liquid ring pump through the water supply pipeline for recycling; the second temperature sensor monitors the working fluid temperature Ta at the water inlet of the liquid ring pump, and transmits the temperature signal to the control module; Step 2: The control module determines the temperature. If Ta≤Tmin, the first electric heater is started to heat the working fluid, and the second and third electric heaters are started to heat the working fluid, so as to accelerate the temperature increase in the entire system and ensure that no crystallization occurs in the suction and exhaust channels of the liquid ring pump system. If Ta≥Tmax, the liquid replenishment electronic control valve is opened to replenish new working fluid with a lower temperature, so as to quickly reduce the working fluid temperature. Step 3: If the liquid level of the steam-water separator exceeds the normal value due to the addition of new working fluid, the liquid level sensor will transmit the liquid level signal to the control module, and the control module will control the drain electric control valve to open and discharge part of the working fluid until the liquid level returns to normal; Step 4, the first temperature sensor monitors the return water temperature Tb of the steam-water separator 2, and by comparing the difference between Tb and Ta, it is determined whether the heat exchanger 5 or the second temperature sensor is faulty, and then the control module issues a fault alarm.

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