阅读说明：本技术 油田伴生气回收过程中的冷却水流量控制方法 (Cooling water flow control method in oilfield associated gas recovery process ) 是由 杨伟森 陈首挺 吴泰忠 李松峰 于 2021-08-31 设计创作，主要内容包括：本发明提供了一种油田伴生气回收过程中的冷却水流量控制方法,包括：(1)在控制模块中预设好冷凝后的气体温度值t-(0)和大幅调整的允许偏差范围率dt；(2)检测热交换前、后的油田伴生气的温度值t-(1)、t-(2),以及热交换前、后的冷却水温度值T-(3)、T-(4),并反馈到控制模块；(3)当︱(t-(2)-t-(0))/t-(0)︱>dt时,冷却水自动调节阀的开度需大幅调整,当︱(t-(2)-t-(0))/t-(0)︱<dt时,冷却水自动调节阀的开度只需小幅调整；(4)确定冷却水自动调节阀现有的开度值；(5)计算冷却水自动调节阀需调整的新开度值；(6)调整好冷却水自动调节阀的开度后,再回到步骤2,从而实现冷却水流量的循环控制。本发明通过实时、精准地控制冷却水自动调节阀的开度,确保液环压缩机系统高效稳定地工作。(The invention provides a method for controlling cooling water flow in an oil field associated gas recovery process, which comprises the following steps: (1) the gas temperature value t after condensation is preset in the control module 0 And a greatly adjusted allowable deviation range rate dt; (2) detecting the temperature value t of the oilfield associated gas before and after heat exchange 1 、t 2 And cooling water temperature values T before and after heat exchange 3 、T 4 And fed back to the control module; (3) moment | t 2 ‑t 0 )/t 0 ︱>dt, the opening of the cooling water automatic regulating valve needs to be adjusted greatly, when an agent (t) 2 ‑t 0 )/t 0 ︱<In dt, the opening degree of the automatic cooling water regulating valve only needs to be adjusted slightly; (4) determining the existing opening value of the automatic cooling water regulating valve; (5) calculating a new opening value of the automatic cooling water regulating valve to be regulated; (6) and (3) after the opening degree of the cooling water automatic regulating valve is adjusted, returning to the step (2), thereby realizing the circulation control of the flow of the cooling water. The invention ensures the high-efficiency and stable operation of the liquid ring compressor system by accurately controlling the opening of the cooling water automatic regulating valve in real time.)

1. A method for controlling cooling water flow in an oilfield associated gas recovery process is characterized by comprising the following steps: the method comprises the following steps:

step 1, presetting in a control moduleTemperature value t of condensed gas₀And a greatly adjusted allowable deviation range rate dt;

step 2, the first temperature transmitter detects the temperature t of the oilfield associated gas before heat exchange₁The second temperature transmitter detects the temperature value t of the oilfield associated gas after heat exchange₂The third temperature transmitter detects the temperature value T of the cooling water before heat exchange₃The fourth temperature transmitter detects the temperature value T after the heat exchange of the cooling water₄Feeding back to the control module;

step 3-1, when an agent (t)₂-t₀)/t₀︱>dt, the opening of the cooling water automatic regulating valve needs to be greatly adjusted, if t is the time₀<t₂And if the opening of the automatic cooling water regulating valve is 100%, the control module gives an alarm to prompt an operator to check whether the cooling water system has a fault, and if the opening of the automatic cooling water regulating valve is not 100%, the control module calculates the opening adjusting quantity Ks of the automatic cooling water regulating valve₂；

Step 3-2, when an agent (t)₂-t₀)/t₀︱<during dt, the opening degree of the automatic cooling water regulating valve is only slightly adjusted, and the control module calculates the opening degree adjusting quantity Ks of the automatic cooling water regulating valve₂；

Step four, determining the existing opening value Ks of the automatic cooling water regulating valve₁Ks is an opening value before the opening is readjusted;

step five, calculating a new opening value Ks (Ks) to be adjusted of the automatic cooling water regulating valve₁+Ks₂Then readjusting the opening degree;

and step six, after the opening degree of the cooling water automatic regulating valve is adjusted, returning to the step 2, and thus realizing the circulation control of the flow of the cooling water.

2. The method for controlling the flow of cooling water in an oilfield associated gas recovery process of claim 1, wherein the method comprises the following steps: when step 3-1 is executed, the opening adjustment amount of the automatic cooling water regulating valve is calculated by an empirical formula as follows:

Ks₂＝S₃*V₀*(t₁-t₂)/(T₄-T₃)/d²；

in the formula, V₀: rated air extraction quantity of the liquid ring compressor, unit: m is³/min；

t₁: the inlet air temperature detected by the first temperature transmitter (i.e. the oilfield associated gas temperature before heat exchange) has the unit: DEG C;

t₂: the exhaust temperature detected by the second temperature transmitter (i.e. the oilfield associated gas temperature after heat exchange) has the unit: DEG C;

T₃: the inlet water temperature of the cooling water (i.e., the temperature of the cooling water before heat exchange) detected by the third temperature transmitter, in: DEG C;

T₄: the outlet water temperature of the cooling water detected by the fourth temperature transmitter is as follows, unit: DEG C;

d: drift diameter of cooling water automatic regulating valve, unit: m;

S₃: the opening degree of the cooling water automatic regulating valve calculates an empirical coefficient, and the value range is usually as follows: 1 to 10E-5.

3. The method for controlling the flow of cooling water in an oilfield associated gas recovery process of claim 2, wherein: when step 3-2 is executed, the opening adjustment amount of the automatic cooling water regulating valve is calculated by an empirical formula as follows:

Ks₂＝S₄*V₀*(t₁-t₂)/(T₄-T₃)/d²；

in the formula, S₄: the opening degree calculation empirical coefficient of the cooling water automatic regulating valve usually has the following value range: 0.5 to 6E-5.

4. The method for controlling the flow rate of cooling water in an oilfield associated gas recovery process according to any one of claims 1 to 4, wherein: and (3) when the step (2) is executed, replacing the first temperature transmitter, the second temperature transmitter, the third temperature transmitter and the fourth temperature transmitter with a first temperature sensor, a second temperature sensor, a third temperature sensor and a fourth temperature sensor respectively.

Technical Field

The invention belongs to the technical field of oilfield associated gas recovery, and particularly relates to a cooling water flow control method in an oilfield associated gas recovery process.

Background

The associated gas of oil field, i.e. the low-pressure natural gas which is generated or produced during the exploitation process of oil field, is directly discharged or burnt, and the treatment mode will undoubtedly cause environmental pollution and energy waste. In recent years, various technical schemes have been developed by those skilled in the art for the recycling of oil field associated gas, and many of the technical schemes are disclosed in the form of patent application or published academic papers or are disclosed to be applied to the production practice of oil fields.

Generally, the conventional oilfield associated gas recovery technology plays an active role in protecting the environment and improving the resource utilization rate, but the conventional oilfield associated gas recovery technology has disadvantages in that, in the process of processing oilfield associated gas, the conventional technology conveys and pressurizes the oilfield associated gas by a screw compressor system (a subsystem of the oilfield associated gas recovery system), and recovers and utilizes the oilfield associated gas after other processes. On one hand, because the temperature of the oilfield associated gas is usually as high as 140 ℃, and the flow rate is greatly changed, the minimum flow rate value can be zero, so that the working pressure of the equipment is stabilized by regulating and refluxing some discharged gas to the air inlet of the screw compressor; on the other hand, the process of the screw compressor compressing the gas also causes a large temperature rise (generally reaching more than 90 ℃), so that the exhaust temperature rise of the screw compressor is remarkably increased, the fault rate of the screw compressor thermal expansion blocking or oil drop coking blocking is increased, and the gas flow at the inlet of the screw compressor is obviously reduced. The obvious reduction of the gas flow at the inlet of the screw compressor can cause the phenomenon of gas flow stall, the failure of pressure discharge and even the backflow of gas, so that the screw compressor generates large surge, and in severe cases, parts of the screw compressor can fall off or be damaged. In addition, the low-pressure natural gas contains more water droplets, and condensed water in a condenser before the screw compressor is sucked into the screw compressor along with the gas. When the water content of the sucked gas is excessive, the problems of blockage of a screw compressor flow passage, aggravation of abrasion, enlargement of vibration, emulsification of lubricating oil, rusting of parts and the like can be caused. Therefore, the screw compressor system has more problems in the using process, in order to ensure that the temperature of the screw compressor is not too high in the working process, the condenser cooling gas is required to be arranged at the suction inlet and the discharge outlet of the screw compressor in the prior art, the structural design not only consumes energy, but also a large amount of liquid can be separated out in the subsequent cooling process, and great negative effects are caused on the subsequent flow of the oilfield associated gas recovery system. In summary, in the oilfield associated gas recovery system, the technical solution of conveying and pressurizing by using the subsystem of the screw compressor system is not ideal.

In order to overcome the technical defects of the screw compressor system in the aspect of recovering the oilfield associated gas, the research team of the invention develops the liquid ring compressor system for recovering the oilfield associated gas, and the essence of the invention is that the liquid ring compressor system replaces the screw compressor system, so that the technical effect of the oilfield associated gas recovery system is improved on the whole. Compared with the conventional screw compressor system, the invention has obvious improvement on the recycling of oilfield associated gas. Of course, in the recovery system of the oilfield associated gas, the subsystem of the screw compressor system and the subsystem of the liquid ring compressor system are both used for controlling the cooling water flow, and the liquid ring compressor system has a working principle different from that of the screw compressor system, so that the original cooling water flow control method applied to the screw compressor system is simply applied, and the technical effect of the invention is difficult to be fully exerted.

Disclosure of Invention

The invention aims to provide a cooling water flow control method matched with an oil field associated gas recovery liquid ring compressor system invented by the inventor so as to ensure that the liquid ring compressor system works efficiently and stably and greatly improve the technical effect of oil field associated gas recovery.

Before introducing the technical scheme adopted by the invention for achieving the purpose, an oilfield associated gas recovery liquid ring compressor system serving as a technical means of the invention is necessarily introduced, and the system comprises a first temperature transmitter, a control module, a condenser, a first pressure transmitter, a return gas automatic regulating valve, a second temperature transmitter, a liquid ring compressor, a gas-water separator, a gas return pipeline, an exhaust pipe, a second pressure transmitter, a gas-water separator valve, a water return pipeline, a heat exchanger, a liquid ring compressor discharge pipe, a liquid ring compressor air inlet pipeline, a cooling water automatic regulating valve, a third temperature transmitter, a condenser inlet pipeline, a fourth temperature transmitter, a liquid level meter, a cooling water inlet pipe and a cooling water outlet pipe;

the inlet pipeline of the condenser is communicated with the condenser, the air inlet pipeline of the liquid ring compressor, the discharge pipe of the liquid ring compressor and the air-water separator in sequence; the cooling water inlet pipe is communicated with the condenser and the cooling water outlet pipe in sequence, and the cooling water automatic regulating valve is arranged on the cooling water inlet pipe or the cooling water outlet pipe;

the upper part of the gas-water separator is communicated with one end of an exhaust pipe, the other end of the exhaust pipe is provided with an exhaust port, the side surface of the exhaust pipe is provided with an opening communicated with a gas return pipeline, and a return gas automatic regulating valve is arranged on the gas return pipeline; the lower part of the gas-water separator is communicated with a water return pipeline, a heat exchanger and a liquid ring compressor in sequence; the second pressure transmitter, the gas-water separator valve and the liquid level meter are respectively communicated with the gas-water separator;

the first temperature transmitter, the first pressure transmitter, the return gas automatic regulating valve, the second temperature transmitter, the second pressure transmitter, the gas-water separator valve, the cooling water automatic regulating valve, the third temperature transmitter and the fourth temperature transmitter are in communication connection with the control module. The control module is preferably a single chip microcomputer, a Programmable Logic Controller (PLC) or an industrial personal computer.

In the technical scheme, a water pipeline inside the condenser, a cooling water inlet pipe and a cooling water outlet pipe which are communicated with the condenser, and a cooling water automatic regulating valve arranged on the cooling water inlet pipe or the cooling water outlet pipe jointly form a cooling water system in the oilfield associated gas recovery liquid ring compressor system;

in order to achieve the purpose of the invention, the invention provides a method for controlling cooling water flow in the recovery process of oilfield associated gas by taking the oilfield associated gas recovery liquid ring compressor system as a material technical means, which comprises the following steps:

step 1, presetting a condensed gas temperature value t in a control module₀And a greatly adjusted allowable deviation range rate dt;

step 2, the first temperature transmitter detects the temperature t of the oilfield associated gas before heat exchange₁The second temperature transmitter detects the temperature value t of the oilfield associated gas after heat exchange₂The third temperature transmitter detects a cooling water temperature value T3 before heat exchange, and the fourth temperature transmitter detects a cooling water temperature value T4 after heat exchange and feeds back the temperature values to the control module;

step 3-1, when an agent (t)₂-t₀)/t₀︱>dt, the opening of the cooling water automatic regulating valve needs to be greatly adjusted, if t is the time₀<t₂And if the opening of the automatic cooling water regulating valve is 100%, the control module gives an alarm to prompt an operator to check whether the cooling water system has a fault, and if the opening of the automatic cooling water regulating valve is not 100%, the control module calculates the opening adjusting quantity Ks of the automatic cooling water regulating valve₂；

Step 3-2, when an agent (t)₂-t₀)/t₀︱<during dt, the opening degree of the automatic cooling water regulating valve is only slightly adjusted, and the control module calculates the opening degree adjusting quantity Ks of the automatic cooling water regulating valve₂；

Step four, determining the existing opening value Ks of the automatic cooling water regulating valve₁Ks is the value before readjusting the openingAn opening value;

step five, calculating a new opening value Ks (Ks) to be adjusted of the automatic cooling water regulating valve₁+Ks₂Then readjusting the opening degree;

and step six, after the opening degree of the cooling water automatic regulating valve is adjusted, returning to the step 2, and thus realizing the circulation control of the flow of the cooling water.

On the basis of the technical scheme, the invention can adopt the following additional technical means so as to better realize the aim of the invention:

when step 3-1 is executed, the opening adjustment amount of the automatic cooling water regulating valve is calculated by an empirical formula as follows:

Ks₂＝S₃*V₀*(t₁-t₂)/(T₄-T₃)/d²；

in the formula, V₀: rated air extraction quantity of the liquid ring compressor, unit: m is³/min；

t₁: the inlet air temperature detected by the first temperature transmitter (i.e. the oilfield associated gas temperature before heat exchange) has the unit: DEG C;

t₂: the exhaust temperature detected by the second temperature transmitter (i.e. the oilfield associated gas temperature after heat exchange) has the unit: DEG C;

T₃: the inlet water temperature of the cooling water (i.e., the temperature of the cooling water before heat exchange) detected by the third temperature transmitter, in: DEG C;

T₄: the outlet water temperature of the cooling water detected by the fourth temperature transmitter is as follows, unit: DEG C;

d: the drift diameter of the cooling water automatic regulating valve 17, unit: m;

S₃: the opening degree of the cooling water automatic regulating valve 17 calculates an empirical coefficient, and the value range is usually: 1 to 10E-5.

Further, in the step 3-2, the opening degree adjustment amount of the automatic cooling water regulating valve is calculated by an empirical formula as follows:

Ks₂＝S₄*V₀*(t₁-t₂)/(T₄-T₃)/d²；

in the formula, S₄: the opening degree calculation empirical coefficient of the cooling water automatic regulating valve usually has the following value range: 0.5 to 6E-5.

It should be noted that, when step 2 in the above technical solution is executed, the first temperature transmitter, the second temperature transmitter, the third temperature transmitter, and the fourth temperature transmitter may be respectively replaced by a first temperature sensor, a second temperature sensor, a third temperature sensor, and a fourth temperature sensor.

The invention has the following main beneficial effects:

the invention can effectively control the flow of the cooling water in a reasonable interval by accurately controlling the opening of the automatic cooling water regulating valve in real time, thereby ensuring that a liquid ring compressor system works efficiently and stably and greatly improving the technical effect of recovering the oilfield associated gas.

Drawings

FIG. 1 is a block diagram of the basic structure and operation of an oilfield associated gas recovery liquid ring compressor system as a matter technical means of the present invention;

FIG. 2 is a schematic diagram of the structure and operation of one embodiment of an oilfield associated gas recovery liquid ring compressor system as a matter of skill in the present disclosure;

FIG. 3 is an enlarged view of a portion of the air induction system of FIG. 2;

fig. 4 is a partially enlarged view of the cooling water system of fig. 2.

In the figure:

1-a first temperature transmitter; 2-a control module;

3-a condenser; 4-a first pressure transmitter;

5-return gas automatic regulating valve; 6-second temperature transmitter;

7-liquid ring compressor; 8-gas-water separator;

9-gas return line; 10-exhaust pipe;

11-second pressure transmitter 12-gas-water separator valve;

13-return water line; 14-a heat exchanger;

15-liquid ring compressor discharge pipe; 16-liquid ring compressor inlet pipe;

17-automatic regulating valve for cooling water; 18-third temperature transmitter;

19-condenser inlet line; 20-fourth temperature transmitter;

21-a liquid level meter; 22-cooling water inlet pipe;

23-cooling water outlet pipe.

Detailed Description

In order to facilitate a better understanding of the technical solution of the present invention for those skilled in the art, an embodiment of an oilfield associated gas recovery liquid ring compressor system as a material technical means of the present invention is first described below with reference to the accompanying drawings:

as shown in fig. 1 in combination with fig. 2, fig. 3 and fig. 4, an oilfield associated gas recovery liquid ring compressor system includes a first temperature transmitter 1, a control module 2, a condenser 3, a first pressure transmitter 4, a return gas automatic regulating valve 5, a second temperature transmitter 6, a liquid ring compressor 7, a gas-water separator 8, a gas return pipeline 9, an exhaust pipe 10, a second pressure transmitter 11, a gas-water separator valve 12, a water return pipeline 13, a heat exchanger 14, a liquid ring compressor discharge pipe 15, a liquid ring compressor intake pipeline 16, a cooling water automatic regulating valve 17, a third temperature transmitter 18, a condenser inlet pipeline 19, a fourth temperature transmitter 20, a liquid level meter 21, a cooling water inlet pipe 22 and a cooling water outlet pipe 23;

the condenser inlet pipeline 19 is sequentially communicated with the condenser 3, the liquid ring compressor air inlet pipeline 16, the liquid ring compressor 7, the liquid ring compressor discharge pipe 15 and the gas-water separator 8, wherein the condenser inlet pipeline 19, the ventilation pipeline inside the condenser 3, the liquid ring compressor air inlet pipeline 16, the liquid ring compressor 7 and the liquid ring compressor discharge pipe 15 form an air inlet system in the liquid ring compressor system (see fig. 3); a water pipeline inside the condenser 3, a cooling water inlet pipe 22 and a cooling water outlet pipe 23 which are communicated with the condenser 3, and a cooling water automatic regulating valve 17 (the cooling water automatic regulating valve 17 can also be arranged on the cooling water outlet pipe 23) which is arranged on the cooling water inlet pipe 22 jointly form a cooling water system in the liquid ring compressor system (see fig. 4);

one side of the gas-water separator 8 is communicated with one end of an exhaust pipe 10, the other end of the exhaust pipe 10 is provided with an exhaust port, the side surface of the exhaust pipe 10 is provided with an opening communicated with a gas return pipeline 9, and a return gas automatic regulating valve 5 is arranged on the gas return pipeline 9; the other side of the gas-water separator 8 is communicated with a water return pipeline 13, a heat exchanger 14 and a liquid ring compressor 7 in sequence; the second pressure transmitter 11, the gas-water separator valve 12 and the liquid level meter 21 are respectively communicated with the gas-water separator 8;

the first temperature transmitter 1, the first pressure transmitter 4, the return air automatic regulating valve 5, the second temperature transmitter 6, the second pressure transmitter 11, the gas-water separator valve 12, the cooling water automatic regulating valve 17, the third temperature transmitter 18, the fourth temperature transmitter 20 and the liquid level meter 21 are in communication connection with the control module 2.

It is emphasized that for the sake of accuracy and simplicity, the present specification adds ordinal terms such as first temperature transmitter, second temperature transmitter, third temperature transmitter, etc. to the names of some devices or components, and different ordinal terms only indicate that the corresponding devices or components are located at different positions and controlled objects in the oilfield associated gas recovery liquid ring compressor system of the present invention, and besides, the ordinal terms do not necessarily have other limiting roles. It should be noted that, when the technical solution of the present invention is actually implemented, each temperature transmitter in this embodiment may be replaced by a corresponding temperature sensor, and similarly, each pressure transmitter in this embodiment may also be replaced by a corresponding pressure sensor. In addition, the control module 2 in this embodiment may be a single chip microcomputer, a PLC (programmable logic controller), an industrial personal computer, or the like having a corresponding control function in the prior art.

The structural features of an embodiment of the oilfield associated gas recovery liquid ring compressor system as a matter technical means of the present invention are described above with reference to the accompanying drawings, and the working process thereof is further described below:

when the gas-water separator works, water is supplied to the gas-water separator 8 to a certain liquid level through the gas-water separator valve 12, working water flows into the liquid ring compressor 7 through the water return pipeline 13 and the heat exchanger 14, and at the moment, the liquid ring compressor 7 can be started to begin to suck oilfield associated gas. The sucked oil field associated gas enters the condenser 3 through the condenser inlet pipeline 19, the cooling water enters the condenser 3 through the cooling water inlet pipe 22 and the cooling water automatic regulating valve 17 to exchange heat with the oil field associated gas for cooling, and then the cooling water is discharged through the cooling water outlet pipe 23. The cooled oilfield associated gas (with part of moisture) enters the liquid ring compressor 7 through the liquid ring compressor inlet pipeline 16, and is discharged into the gas-water separator 8 after being compressed. The oilfield associated gas with water is separated in the gas-water separator 8, the separated liquid water is converged into the working water, flows into the water return pipeline 13 from the bottom of the gas-water separator 8, is cooled by the heat exchanger 14 and then enters the liquid ring compressor 7 for recycling, and the separated gas is discharged out of the gas-water separator 8 through the exhaust pipe 10 and then is communicated to the next process flow (or recycled by a subsequent treatment procedure or returned to the condenser 3 through the gas return pipeline 9 according to specific conditions).

The above working process is completed under the control of the control module 2, for example, the control module 2 detects the pressure value p1 of the oilfield associated gas in the liquid ring compressor inlet pipeline 16 (i.e. the inlet pressure value of the liquid ring compressor 7) according to the first pressure transmitter 4, and compares p1 with a preset pressure value p0 to determine whether the automatic regulating valve 5 needs to be opened to realize gas backflow.

In another example, the control module 2 detects the temperature t of the oilfield associated gas before heat exchange according to the first temperature transmitter 1₁The temperature value t of the oilfield associated gas after heat exchange detected by the second temperature transmitter 6₂The required flow rate of the cooling water is calculated by the temperature value T3 of the cooling water before heat exchange detected by the temperature transmitter 18, the temperature value T4 of the cooling water after heat exchange detected by the temperature transmitter 20, and the air suction amount of the liquid ring compressor 7, so that the opening degree of the cooling water automatic regulating valve 17 is determined.

In general, the control of the oilfield associated gas recovery liquid ring compressor system is divided into control of the return gas and control of the cooling water flow, which are two processes that are performed simultaneously but relatively independent. The method for controlling the flow rate of cooling water is described in detail below, and comprises the following steps:

step 1, presetting a condensed gas temperature value t in a control module 2₀And a greatly adjusted allowable deviation range rate dt;

step 2, the first temperature transmitter 1 detects the temperature value t of the oilfield associated gas before heat exchange₁The second temperature transmitter 6 detects the temperature value t of the oilfield associated gas after heat exchange₂The third temperature transmitter 18 detects a temperature value T3 of the cooling water before heat exchange, and the fourth temperature transmitter 20 detects a temperature value T4 of the cooling water after heat exchange, and feeds the temperature value back to the control module 2;

step 3-1, when an agent (t)₂-t₀)/t₀︱>dt, the opening of the automatic cooling water control valve 17 is adjusted to a large extent, if t is reached₀<t₂If the opening degree of the automatic cooling water regulating valve 17 is 100%, the control module 2 gives an alarm to prompt an operator to check whether the cooling water system is faulty, and if the opening degree of the automatic cooling water regulating valve 17 is not faulty, the control module 2 calculates the opening degree adjustment Ks of the automatic cooling water regulating valve 17₂；

Generally speaking, the algorithm in the software of the control module 2 (such as a single chip microcomputer, an industrial personal computer or a PLC) can complete the opening adjustment Ks of the cooling water automatic regulating valve 17₂However, in the case of a plurality of experiments by the inventors, when the step 3-1 is executed, the opening degree adjustment amount Ks of the cooling water automatic adjustment valve 17 is calculated according to the following empirical formula₂The technical effect is better:

Ks₂＝S₃*V₀*(t₁-t₂)/(T₄-T₃)/d²；

in the formula, V₀: rated air extraction quantity of the liquid ring compressor, unit: m is³/min；

t₁: the intake air temperature (i.e., the oilfield associated gas temperature before heat exchange) detected by the first temperature transmitter 1 has the unit: DEG C;

t₂: the exhaust gas temperature detected by the second temperature transmitter 6 (i.e., the oilfield associated gas temperature after heat exchange) has the unit: DEG C;

T₃: the cooling water inlet temperature (i.e., the temperature of the cooling water before heat exchange) detected by the third temperature transmitter 18, in units of: DEG C;

T₄: the cooling water outlet temperature (i.e., the temperature after the cooling water heat exchange) detected by the fourth temperature transmitter 20, unit: DEG C;

d: the drift diameter of the cooling water automatic regulating valve 17, unit: m;

S₃: the opening degree of the cooling water automatic regulating valve 17 calculates an empirical coefficient, and the value range is usually: 1-10E-5; (the value range mainly influences the response speed of adjustment, and when the method is implemented, the average value is generally taken and can be adjusted according to the actual debugging condition.)

Step 3-2, when an agent (t)₂-t₀)/t₀︱<dt, the opening degree of the cooling water automatic regulating valve 17 only needs to be adjusted slightly, and the control module 2 can calculate the opening degree adjusting quantity Ks of the cooling water automatic regulating valve 17₂；

Similar to the step 3-1, the calculation of the opening adjustment amount of the cooling water automatic regulating valve 17 can also be completed by an algorithm in the software of the control module 2, but from the condition of multiple experiments of the inventor, when the step 3-2 is executed, the opening adjustment amount of the return air automatic regulating valve 5 is calculated according to the following empirical formula, so that the technical effect is better:

Ks₂＝S₄*V₀*(t₁-t₂)/(T₄-T₃)/d²；

in the formula, S₄: the opening degree of the cooling water automatic regulating valve 17 calculates an empirical coefficient, and the value range is usually: 0.5-6E-5; (the value range mainly influences the response speed of adjustment, and when the method is implemented, the average value is generally taken and can be adjusted according to the actual debugging condition.)

Step four, determining the existing opening value Ks of the cooling water automatic regulating valve 17₁Ks is an opening value before the opening is readjusted;

step five, calculating a new opening value Ks ═ Ks of the cooling water automatic regulating valve 17 to be regulated₁+Ks₂Then readjusting the opening degree;

and step six, after the opening degree of the cooling water automatic regulating valve 17 is adjusted, returning to the step 2, thereby realizing the circulation control of the flow of the cooling water.

The cooling water flow control method is further explained by substituting specific numerical values in the experiment as follows:

in this experiment, the rated suction amount V of the liquid ring compressor 7₀＝12m³Min; presetting the temperature t of the condensed gas₀45 ℃ and the widely adjusted allowable deviation range rate dt is 10%, the valve diameter of the used automatic cooling water regulating valve 17 is d 80mm 0.08m, and the temperature value t detected by the first temperature transmitter 1 is₁80 deg.c, the temperature value t detected by the second temperature transmitter 6₂50 ℃, the temperature value T detected by the third temperature transmitter 18₃25 deg.c, the temperature value T detected by the fourth temperature transmitter 20₄＝40℃S₃Value 8E-5

At this time, | (t)₂-t₀)/t₀︱＝(50-45)/45≈0.11>dt, the opening degree of the automatic cooling water regulating valve 17 needs to be adjusted to a large extent:

Ks₂＝0.00008*V₀*(t₁-t₂)/(T₄-T₃)/d²

＝0.00008*12*(80-50)/(40-25)/0.08²＝0.3＝30％

at this time, Ks₁＝Ks＝0，

Calculating the opening value Ks of the automatic cooling water regulating valve 17 to be adjusted₁+Ks₂After the opening degree of the automatic cooling water control valve 17 is readjusted to 30%, the process returns to step 2, and the circulation control of the cooling water is realized.