Condensing temperature self-control adjusting system

Abstract

The utility model relates to a condensation temperature self-control adjusting system which comprises a condensation unit and two sets of refrigerating units, the refrigerating units receive tail gas through a main air supply pipeline connected in parallel, three sets of heat exchange cold boxes are arranged in each set, different refrigerants are introduced into the heat exchange cold boxes respectively, and the temperature of the tail gas in the heat exchange cold boxes is detected by a temperature transmitter; the temperature transmitter is interlocked with a refrigerant liquid inlet valve of the heat exchange cold box, refrigerant conveying is controlled through the temperature of tail gas in the heat exchange cold box, fine management of the oil gas condensation temperature is achieved, damage to a compressor caused by backflow of the refrigerant in the whole working state is avoided, and the working condition of a condensation recovery system is efficiently guaranteed; the system efficiency is improved, and the operation safety is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of condensation, in particular to a condensation temperature automatic control and adjustment system. Background Art

[0002] During the loading and unloading of oil and chemical products at the terminal, organic matter harmful to the environment will be discharged. At present, the commonly used tail gas treatment technologies in the industry are mostly based on the "condensation + catalytic oxidation" treatment mode. The principle is that the logic acquisition signal point of the refrigerant liquid supply valve control loop is located in the heat exchange cold box (heat exchange cold box) secondary and tertiary refrigerant return air temperature transmitter, and the liquid refrigerant supply is regulated and controlled by monitoring the vaporization state of the refrigerant in the heat exchange cold box. Through our company's field use, we found that the oil and gas recovery system technology is still insufficient. The existing problems are as follows:

[0003] (1) Due to the differences in the physical and chemical properties of the different oils and gases being processed, in order to prevent crystallization blockage, the control temperature of the condensation recovery process needs to be flexibly adjusted according to the properties of the material. However, the original design refrigeration capacity can only be adjusted by the refrigerant return gas temperature. The control method is not smooth and cannot meet the actual temperature control requirements of the heat exchange cold box.

[0004] (2) The correct working state cannot be identified under special working conditions such as low load of the compressor. When the refrigerant evaporation temperature is lower than the set value, the liquid supply valve is closed and the normal refrigeration process cannot be maintained;

[0005] (3) The control logic of the pneumatic control valve (refrigerant supply valve) is poorly compatible with the on-site refrigeration unit. When the refrigerant evaporation temperature is much higher than the set point, the supply valve will open immediately. The instantaneous increase in the compressor load can easily cause the compressor to shut down due to high current or even over-temperature locking of the bearing. At the same time, as a large amount of liquid refrigerant enters the heat exchange cold box and cannot evaporate in time, the liquid refrigerant reflux may be sucked into the compressor and cause liquid hammer.

[0006] Based on this, we improved the condensate recovery system within the factory to meet production needs. Utility Model Content

[0007] The technical problem to be solved by the utility model is to provide a tail gas condensate collection device which can reduce production risks to the greatest extent, improve oil and gas recovery efficiency, reduce the operating load of the refrigeration unit, and improve work efficiency in view of the deficiencies in the prior art.

[0008] The technical problem to be solved by the utility model is achieved through the following technical solution: a condensation temperature automatic control and adjustment system, the system comprising a condensation unit;

[0009] The condensing unit comprises two refrigeration units, and the feed inlets of the two refrigeration units are connected in parallel with a main air supply pipeline;

[0010] Each group of the refrigeration units includes three groups of heat exchange cold boxes into which different refrigerants are introduced, and the heat exchange cold boxes include refrigerant pipelines and delivery pipelines for introducing tail gas to be condensed. The delivery pipelines of the three groups of heat exchange cold boxes are connected in series, and the delivery pipelines of the three groups of heat exchange cold boxes are connected to the main air supply pipeline through pipelines, and the main air supply pipeline supplies the tail gas to be condensed to the refrigeration unit;

[0011] A refrigerant liquid inlet valve and a refrigerant liquid outlet valve are provided on the inlet and outlet ends of the refrigerant pipelines of the three groups of heat exchange cold boxes;

[0012] Temperature transmitters for detecting the exhaust gas temperature in the heat exchange cold boxes are arranged on the inner walls of the three groups of heat exchange cold boxes. Each of the temperature transmitters is interlocked with the refrigerant inlet valve on the inlet end of the refrigerant pipeline of one of the heat exchange cold boxes. The control logic of the interlocking setting is:

[0013] When the temperature measured by the temperature transmitter is greater than the set value, it means that the exhaust gas temperature is too high, that is, the refrigerant supply should be increased to increase the opening of the refrigerant inlet valve;

[0014] When the temperature measured by the temperature transmitter is lower than the set value, it means that the exhaust gas temperature is too low, that is, the refrigerant supply should be reduced to reduce the opening of the refrigerant inlet valve, or close the refrigerant inlet valve.

[0015] The technical problem to be solved by the utility model can also be achieved through the following technical solutions. In the above-mentioned automatic condensing temperature control system, the refrigerants introduced into the three groups of heat exchange cold boxes are ethylene glycol, R507 refrigerant and ethylene liquid respectively.

[0016] The technical problem to be solved by the utility model can also be achieved through the following technical solutions: in the above-mentioned automatic condensing temperature control system, the refrigerant liquid inlet valve on the inlet end of the refrigerant pipeline is located outside the heat exchange cold box.

[0017] The technical problem to be solved by the utility model can also be achieved through the following technical scheme: in the above-mentioned automatic control system for condensing temperature, the feed inlets of the two groups of refrigeration units are connected in parallel to the main air supply pipeline through a three-way valve.

[0018] Compared with the prior art, the beneficial technical effect of the utility model is that the condensing temperature automatic control system changes the control logic signal point of the refrigerant inlet valve from the traditional temperature measurement at the outlet of the heat exchange cold box to the exhaust gas temperature measurement inside the heat exchange cold box, and can control the refrigerant transportation according to the actual working temperature change of the exhaust gas, thereby realizing the refined management of the oil and gas condensation temperature, and maintaining the working state throughout the whole process, which can effectively avoid the harm of refrigerant reflux to the compressor. At the same time, it can efficiently ensure the working conditions of the condensation recovery system, and greatly improve the system efficiency while ensuring the safety of its operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the utility model when it is applied to an exhaust gas treatment system;

[0020] Figure 2 This is a structural schematic diagram of one of the refrigeration units of the utility model.

[0021] In the figure, 1. Condensing unit; 2. Refrigeration unit; 3. Main air supply pipeline; 4. Fan; 5. Heat exchange cold box; 6. Refrigerant pipeline; 7. Transport pipeline; 8. Refrigerant inlet valve; 9. Refrigerant outlet valve; 10. Temperature transmitter. DETAILED DESCRIPTION

[0022] The specific technical solutions of the present invention are further described below with reference to the accompanying drawings, so as to facilitate further understanding of the present invention by those skilled in the art, and do not constitute any limitation to the rights thereof.

[0023] Example 1, reference Figure 1-2 , a condensation temperature automatic control and regulation system, the system comprises a condensation unit 1;

[0024] The condensing unit 1 comprises two refrigeration units 2, the feed ports of the two refrigeration units 2 are connected in parallel with a total air supply pipeline 3, the feed ports of the two refrigeration units 2 are connected in parallel to the total air supply pipeline 3 through a three-way valve, and a fan 4 for conveying gas can be provided on the total air supply pipeline 3;

[0025] It should be noted that the number of the refrigeration units 2 is not limited to two, and may be multiple;

[0026] Each group of the refrigeration units 2 includes three groups of heat exchange cold boxes 5 into which different types of refrigerants are introduced, and the heat exchange cold boxes 5 include refrigerant pipelines 6 and delivery pipelines 7 for introducing tail gas to be condensed. The delivery pipelines 7 of the three groups of heat exchange cold boxes 5 are connected in series, and the delivery pipelines 7 of the three groups of heat exchange cold boxes 5 are connected to the main air supply pipeline 3 through pipelines, and the main air supply pipeline 3 supplies the tail gas to be condensed to the refrigeration unit 2;

[0027] It should be noted that each group of refrigeration units 2 is not limited to three groups of heat exchange cold boxes 5, but may also be multiple groups of heat exchange cold boxes 5;

[0028] The refrigerants introduced into the three groups of heat exchange cold boxes 5 are ethylene glycol, R507 refrigerant and ethylene liquid respectively;

[0029] It should be noted that the refrigerant of the heat exchange cold box 5 may also be other preparations, and is not limited to ethylene glycol, R507 refrigerant and ethylene liquid;

[0030] In addition, R507 is a refrigerant code, which is made of a mixture of pentafluoroethane and trifluoroethane. Since it is an existing technology, it can be selected according to the use requirements, so its specific composition and its use principle will not be described here;

[0031] A refrigerant liquid inlet valve 8 and a refrigerant liquid outlet valve 9 are provided on the inlet and outlet ends of the refrigerant pipes 6 of the three groups of heat exchange cold boxes 5. The refrigerant liquid inlet valve 8 on the inlet end of the refrigerant pipe 6 is located outside the heat exchange cold box 5.

[0032] Temperature transmitters 10 for detecting the exhaust gas temperature in the heat exchange cold boxes 5 are arranged on the inner walls of the three groups of heat exchange cold boxes 5. The temperature transmitters 10 are prior art, and their models and specifications can be selected according to the use requirements. Each of the temperature transmitters 10 is interlocked with the refrigerant inlet valve 8 on the inlet end of the refrigerant pipeline 6 of one of the heat exchange cold boxes 5. The control logic of the interlocking setting is:

[0033] When the temperature measured by the temperature transmitter 10 is greater than the set value, it means that the exhaust gas temperature is too high, that is, the refrigerant supply should be increased to increase the opening of the refrigerant inlet valve 8;

[0034] When the temperature measured by the temperature transmitter 10 is less than the set value, it means that the exhaust gas temperature is too low, that is, the refrigerant supply should be reduced, thereby reducing the opening of the refrigerant inlet valve 8, or closing the refrigerant inlet valve 8;

[0035] It should be noted that due to the different heat absorption and release characteristics of different refrigerants, the specific value of the set value will also be different, so the specific corresponding values ​​of the temperature set value and the valve opening will not be repeated here.

[0036] The operating principle of the condensing temperature automatic control system is:

[0037] The tail gas discharged during the loading and unloading of oil and chemical products at the terminal is sent to one of the refrigeration units 2 through the fan 4 on the main air supply pipeline 3, and enters the heat exchange cold box 5 of the refrigeration unit 2. After heat exchange in the three heat exchange cold boxes 5, the liquid can enter the oil-water separation tank through the pipeline, and the non-condensable gas (such as a mixed gas with nitrogen as the main component) + a small amount of low-concentration tail gas enters the CO reactor through the pipeline. For details, refer to Figure 1 ;

[0038] In addition, while the three groups of heat exchange cold boxes 5 are condensing the exhaust gas in sequence, the temperature transmitter 10 located in the heat exchange cold box 5 monitors the exhaust gas temperature in real time, and the temperature detection value under normal circumstances can be set as a standard value. When the temperature transmitter 10 measures that the current temperature is greater than the set value, it means that the exhaust gas temperature is too high, that is, the refrigerant supply should be increased to increase the opening of the refrigerant inlet valve 8; when the temperature transmitter 10 measures that the current temperature is less than the set value, it means that the exhaust gas temperature is too low, that is, the refrigerant supply should be reduced to reduce the opening of the refrigerant inlet valve 8, or close the refrigerant inlet valve 8.

Claims

1. A condensing temperature automatic control and adjustment system, characterized in that: The system includes a condensing unit; The condensing unit comprises two refrigeration units, and the feed inlets of the two refrigeration units are connected in parallel with a main air supply pipeline; Each group of the refrigeration units comprises three groups of heat exchange cold boxes into which different types of refrigerants are introduced, the heat exchange cold boxes comprising refrigerant pipelines and delivery pipelines for introducing tail gas to be condensed, and the delivery pipelines of the three groups of heat exchange cold boxes are connected in series; A refrigerant liquid inlet valve and a refrigerant liquid outlet valve are provided on the inlet and outlet ends of the refrigerant pipelines of the three groups of heat exchange cold boxes; Temperature transmitters for detecting the exhaust gas temperature in the heat exchange cold boxes are arranged on the inner walls of the three groups of heat exchange cold boxes, and each of the temperature transmitters is interlocked with the refrigerant liquid inlet valve on the inlet end of the refrigerant pipeline of one of the heat exchange cold boxes.

2. A condensation temperature automatic control and regulation system according to claim 1, characterized in that: The refrigerants introduced into the three groups of heat exchange cold boxes are ethylene glycol, R507 refrigerant and ethylene liquid respectively.

3. The condensing temperature automatic control and adjustment system according to claim 1 is characterized in that: The refrigerant liquid inlet valve on the inlet end of the refrigerant pipeline is located outside the heat exchange cold box.

4. The condensing temperature automatic control and adjustment system according to claim 1 is characterized in that: The feed inlets of the two groups of refrigeration units are connected in parallel to the main air supply pipeline through three-way valves.

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