阅读说明：本技术 测试化学反应失控安全泄放物料流动状态的方法 (Method for testing flow state of chemical reaction out-of-control safe discharge material ) 是由 金满平 王婷 高月 张全 厉鹏 黄飞 李运才 于 2019-04-04 设计创作，主要内容包括：本发明涉及一种测试化学反应失控安全泄放物料流动状态的方法,主要解决现有技术中尚无化学反应失控泄放物料流动状态的测试方法的问题。本发明通过采用一种测试化学反应失控安全泄放物料流动状态的方法,反应器内超压泄放的物料经由泄放管路排至泄放物料收集罐,泄放物料收集罐中的惰性透明液体介质与泄放物料中的液相分层,根据泄放物料收集罐中收集到泄放物料状态,判定泄放物料泄放时的流动状态的技术方案较好地解决了上述问题,可用于测试化学反应失控安全泄放物料流动状态中。(The invention relates to a method for testing the flow state of a chemical reaction runaway safe discharge material, which mainly solves the problem that no test method for the flow state of the chemical reaction runaway discharge material exists in the prior art. The invention adopts the method for testing the flow state of the chemical reaction runaway safety release material, the material which is released at overpressure in the reactor is discharged to the release material collecting tank through the release pipeline, the inert transparent liquid medium in the release material collecting tank is layered with the liquid phase in the release material, and the flow state of the release material when the release material is released is judged according to the state of the release material collected in the release material collecting tank, thereby better solving the problems and being used for testing the flow state of the chemical reaction runaway safety release material.)

1. A method for testing the flow state of chemical reaction out-of-control safe discharge materials comprises the steps that when the temperature of a chemical reaction system in a reactor rises and the reaction out-of-control occurs to cause the pressure in the reactor to exceed the set pressure of a safety valve arranged at the top of the reactor, the safety valve is automatically opened, the materials which are subjected to overpressure discharge in the reactor are discharged into a discharge material collecting tank through a discharge pipeline, and the safety valve is automatically closed after the pressure in the reactor is reduced to the tripping pressure of the safety valve; the material discharged into the discharged material collecting tank enters the discharged material collecting tank through the bottom of the discharged material collecting tank, the discharged material is cooled by the inert transparent liquid medium in the discharged material collecting tank, the liquid phase in the discharged material is layered with the inert liquid medium, and the gas phase in the discharged material enters the gas phase space on the upper layer of the discharged material collecting tank through the inert liquid medium; when the temperature in the discharged material collecting tank is reduced to normal temperature, observing whether a liquid phase contains a liquid material which is layered with the inert liquid medium, if so, indicating that the discharged material contains the liquid material, otherwise, indicating that no liquid material exists; converting the pressure difference delta P which is required to be increased in a gas-phase space in the discharged material collecting tank according to the volume of the collected liquid-phase discharged material, adding the pressure P1 before collecting the discharged material, and comparing the pressure value P2 which is obtained by testing of a pressure sensor after collecting the discharged material, wherein if P2 is greater than P1 plus delta P, the newly increased non-condensable gas is the gas-phase substance in the discharged material, and if P2 is less than or equal to P1 plus delta P, the discharged material does not contain gas; judging the flow state of the discharged material when the discharged material is discharged according to the state of the discharged material collected in the discharged material collecting tank, wherein if the discharged material contains both liquid and gas, the flow state of the discharged material is two-phase flow; if only liquid or gas exists in the discharged material, the flowing state of the discharged material is unidirectional flow.

2. The method for testing the flow state of a chemical reaction runaway safe discharge material as claimed in claim 1, wherein the discharge material collection tank is made of a pressure-resistant transparent material, is filled with an inert transparent liquid medium and is sealed.

3. The method for testing the flow state of the chemical reaction runaway safe bleed material as claimed in claim 1, wherein in the bleed material collection tank, the material discharged into the bleed material collection tank is finally settled on the upper layer or the lower layer of the inert liquid phase material according to the density of the material discharged into the bleed material collection tank and the inert liquid medium.

4. The method for testing the flow condition of a run away safety blowdown material of a chemical reaction of claim 1, wherein the blowdown material collection tank is topped with temperature and pressure sensors.

5. The method for testing the flow state of a chemical reaction runaway safe discharge material as claimed in claim 1, wherein a pressure relief valve is provided at the top of the reactor.

6. The method for testing the flow state of the chemical reaction runaway safety relief material as claimed in claim 1, wherein an agitation device is provided in the reactor.

7. The method for testing the flow state of a chemical reaction runaway safe blowdown material as claimed in claim 1, wherein a pressure relief valve is provided at the top of the blowdown material collection tank.

8. The method for testing the flow state of a chemical reaction runaway safe discharge material as claimed in claim 1, wherein the inert liquid medium is colorless, transparent and does not chemically react with the discharged material and is selected from the group consisting of silicone oil, liquid paraffin, and glycerol.

9. The method for testing the flow state of a chemical reaction runaway safe discharge material as claimed in claim 8, wherein the inert liquid medium is colorless, transparent and non-chemically reactive with the discharged material and is selected from the group consisting of silicone oil and glycerol.

10. The method for testing the flow state of a chemical reaction runaway safe release material as claimed in claim 9, wherein the inert liquid medium is colorless, transparent and non-chemically reactive with the released material and is selected from silicone oils.

Technical Field

The invention relates to a method for testing the flow state of a chemical reaction runaway safe discharge material.

Background

Most production devices in the field of petrochemical industry are provided with safety relief devices, such as safety valves or rupture discs, materials in a pressure vessel are released to a safe region through a relief pipeline by the safety valves or the rupture discs before reaction runaway of a reaction system reaches the maximum allowable pressure of the pressure vessel, so that the temperature and the pressure in the reaction system are reduced, the pressure vessel is protected, and the design of safely relieving the pressure vessel is the most effective safety measure for preventing chemical reaction runaway and overpressure damage at present. Due to the complexity of the problem of chemical reaction runaway, the research on the chemical reaction runaway safety discharge technology is relatively lagged at present, most of research works still stay in the experimental stage, the theoretical research progress is slow, the research method and the research result are not unified so far, no corresponding unified standard exists, and domestic research in the field is blank. At present, safety Relief design related to reaction runaway at home and abroad is mostly based on some methods or guidelines developed by the american society for Emergency Relief system design (DIERS for short). The method developed by DIERS considers that in the chemical runaway safety relief process, the flow of the relief in a container (or equipment) can be divided into single-phase flow, two-phase flow and multiphase flow, the flow state in the container can influence the proportion of gas phase, and further influence the determination of the safety relief amount and the relief capacity of a relief device, and a proper relief design method is selected according to different relief flow states, so that the method is very important for determining the safety relief area of a pressure container and selecting a proper safety relief device. Therefore, the determination of the flow state of the chemical reaction runaway discharge material in the container (or equipment) has very important significance on the determination of the discharge area of the chemical reaction runaway safety discharge device and the selection of the discharge device.

At present, the method developed by DIERS mainly adopts a conservative two-phase flow calculation method for determining the flow state, but the discharge area required by two-phase flow discharge is often much larger than that required by one-way flow discharge, sometimes the calculation result is unreasonable, the calculated discharge aperture even exceeds the diameter of the pressure container, and great trouble is caused to the design of the pressure container and the safety discharge device thereof. If the flow state of the discharged material in the container (or equipment) can be determined by a certain testing means, and the conclusion of single-phase flow is obtained, the required discharge area can be greatly reduced, and the size and the cost of a downstream discharged material collecting and processing system can be effectively reduced.

According to the results of literature search, no relevant report is found on the test method of the flow state of the chemical reaction runaway bleed material.

Disclosure of Invention

The invention aims to solve the technical problem that a method for testing the flow state of the chemical reaction runaway discharge material is not available in the prior art, provides a novel method for testing the flow state of the chemical reaction runaway safety discharge material, and has the advantage of accurate and reliable test result.

In order to solve the problems, the technical scheme adopted by the invention is as follows: a method for testing the flow state of chemical reaction out-of-control safe discharge materials comprises the steps that when the temperature of a chemical reaction system in a reactor rises and the reaction out-of-control occurs to cause the pressure in the reactor to exceed the set pressure of a safety valve arranged at the top of the reactor, the safety valve is automatically opened, the materials which are subjected to overpressure discharge in the reactor are discharged into a discharge material collecting tank through a discharge pipeline, and the safety valve is automatically closed after the pressure in the reactor is reduced to the tripping pressure of the safety valve; the material discharged into the discharged material collecting tank enters the discharged material collecting tank through the bottom of the discharged material collecting tank, the discharged material is cooled by the inert transparent liquid medium in the discharged material collecting tank, the liquid phase in the discharged material is layered with the inert liquid medium, and the gas phase in the discharged material enters the gas phase space on the upper layer of the discharged material collecting tank through the inert liquid medium; when the temperature in the discharged material collecting tank is reduced to normal temperature, observing whether a liquid phase contains a liquid material which is layered with the inert liquid medium, if so, indicating that the discharged material contains the liquid material, otherwise, indicating that no liquid material exists; converting the pressure difference delta P which is required to be increased in a gas-phase space in the discharged material collecting tank according to the volume of the collected liquid-phase discharged material, adding the pressure P1 before collecting the discharged material, and comparing the pressure value P2 which is obtained by testing of a pressure sensor after collecting the discharged material, wherein if P2 is greater than P1 plus delta P, the newly increased non-condensable gas is the gas-phase substance in the discharged material, and if P2 is less than or equal to P1 plus delta P, the discharged material does not contain gas; judging the flow state of the discharged material when the discharged material is discharged according to the state of the discharged material collected in the discharged material collecting tank, wherein if the discharged material contains both liquid and gas, the flow state of the discharged material is two-phase flow; if only liquid or gas exists in the discharged material, the flowing state of the discharged material is unidirectional flow.

In the above technical scheme, preferably, the discharge material collecting tank is made of a pressure-resistant transparent material, and is filled with an inert transparent liquid medium and is sealed.

In the above technical scheme, preferably, in the discharged material collecting tank, the material discharged into the discharged material collecting tank is finally stood on the upper layer or the lower layer of the inert liquid phase material according to the density of the material and the inert liquid medium discharged into the discharged material collecting tank.

In the above technical solution, preferably, the top of the blowdown material collection tank is equipped with a temperature and pressure sensor.

In the above technical solution, preferably, a pressure relief valve is provided at the top of the reactor.

In the above technical solution, preferably, a stirring device is provided in the reactor.

Among the above-mentioned technical scheme, preferably, the blowdown material collection tank top is equipped with the relief valve.

In the above technical solution, preferably, the inert liquid medium is colorless and transparent, does not react with the discharged material chemically, and is selected from silicone oil, liquid paraffin, or glycerol, more preferably, is selected from silicone oil or glycerol, and most preferably, is selected from silicone oil.

The invention provides a test method for determining the flow state of a chemical reaction uncontrolled discharge material, and production enterprises and design units engaged in dangerous processes in the fields of petroleum, chemical industry, pharmacy and the like have higher requirements on the method. With the gradual improvement of the process safety control technology of petrochemical production enterprises in China, the invention has considerable application and popularization values in production enterprises and design units engaged in the fields of petroleum, chemical engineering, pharmacy and the like. At present, a test method for determining the flow state of the chemical reaction runaway discharging material, which is similar to the technology of the invention, is not established and designed at home and abroad, and a commercial test method for determining the flow state of the chemical reaction runaway discharging material, which is similar to the technology of the invention, is also not available. The invention carries out the test of the flow state of the discharged material out of control of the decomposition reaction of the hydrogen peroxide and the cumene hydroperoxide, can obtain the accurate test result that the flow state of the discharged material is two-phase flow, and obtains better technical effect.

Drawings

FIG. 1 is a schematic flow diagram of the process of the present invention.

In the figure 1, 1-a reactor relief valve, 2-a reactor, 3-a chemical reaction system material, 4-a reactor stirring device, 5-a reactor relief valve, 6-a discharged material pipeline, 7-a discharged material collecting tank relief valve, 8-a discharged material collecting tank, 9-a collected discharged material liquid phase substance, 10-an inert transparent liquid medium arranged in the discharged material collecting tank, 11-a discharged material collecting tank temperature sensor and 12-a discharged material collecting tank pressure sensor.

FIG. 2 is a graph showing the pressure of the reaction system in the reactor in example 2 as a function of time.

FIG. 3 is a graph of the pressure in the bleed material collection tank as a function of temperature for example 2.

FIG. 4 is a graph showing the pressure of the reaction system in the reactor according to example 3 as a function of time.

FIG. 5 is a graph of the pressure in the bleed material collection tank versus temperature for example 3.

The present invention will be further illustrated by the following examples, but is not limited to these examples.

Detailed Description

[ example 1 ]

A method for testing the flow state of a chemical reaction out-of-control safe discharged material comprises the steps that as shown in figure 1, a pressure release valve, a stirring device and a safety valve are arranged at the top of a reactor, the safety valve is connected with the bottom of a discharged material collecting tank through a discharged material pipeline, an inert transparent liquid medium is filled in the discharged material collecting tank, and the pressure release valve, a temperature sensor and a pressure sensor are arranged on the discharged material collecting tank.

1. When the temperature of a chemical reaction system in the reactor rises and the reaction is out of control, the pressure in the reactor exceeds the set pressure of a safety valve arranged at the top of the reactor, the safety valve is automatically opened, the material which is subjected to overpressure release in the reactor is discharged into a release material collecting tank which is made of pressure-resistant transparent material, is internally provided with inert transparent liquid medium and is sealed through a release pipeline, and the safety valve is automatically closed after the pressure in the reactor is reduced to the tripping pressure of the safety valve.

2. The material discharged into the discharged material collecting tank through the discharge pipeline by the safety valve enters the discharged material collecting tank through the bottom of the discharged material collecting tank, the discharged material is cooled by the inert transparent liquid medium in the discharged material collecting tank, the liquid phase in the discharged material is layered with the inert liquid medium, and finally stands on the upper layer or the lower layer of the inert liquid phase material according to the density of the inert liquid medium and the liquid phase in the discharged material; the gas phase in the discharged material enters the gas phase space on the upper layer of the discharged material collecting tank through the inert liquid medium.

3. The top of the discharged material collecting tank is provided with a temperature sensor and a pressure sensor, when the temperature in the discharged material collecting tank is reduced to normal temperature, whether a liquid phase contains a liquid material which is layered with an inert liquid medium or not is observed, if so, the discharged material contains the liquid material, otherwise, the discharged material does not contain the liquid material; according to the volume of the collected liquid-phase discharged material, the pressure difference delta P which is required to be increased in the gas-phase space in the discharged material collecting tank is converted, the pressure P1 before the discharged material is collected is added, and the pressure value P2 is compared with the pressure value obtained by the pressure sensor after the discharged material is collected, if P2 is greater than P1 plus delta P, the newly increased non-condensable gas is the gas-phase substance in the discharged material, and if P2 is not greater than P1 plus delta P, the discharged material does not contain gas.

4. According to the state of the discharged material collected in the discharged material collecting tank, the flow state of the discharged material when the pressure container (equipment) is discharged can be judged. If the discharged material contains both liquid and gas, the flow state of the discharged material is two-phase flow; if only liquid or gas exists in the discharged material, the flowing state of the discharged material is unidirectional flow.

[ example 2 ]

According to the conditions and steps described in the examples, the flow state test of the bleed material with uncontrolled decomposition reaction of hydrogen peroxide is carried out, and the specific steps are as follows:

1. setting the automatic opening pressure of a safety valve at the top of the reactor to be 0.7MPa, and injecting inert liquid medium silicone oil into the discharged material collecting tank;

2. adding a hydrogen peroxide solution with the concentration of 10% into a reactor, wherein the filling coefficient is not more than 60%, heating to 40 ℃ at the heating rate of 1.0 ℃/min, stopping heating, keeping the system in a heat insulation state, gradually increasing the temperature and the pressure of the reaction system, starting a safety valve when the pressure reaches the discharge pressure of a safety valve at the top of the reactor to be 0.7MPa, and discharging materials reach a discharge material collecting tank through a discharge pipeline;

3. the test results in a graph of the pressure of the reaction system in the reactor as a function of time, as shown in FIG. 2.

As can be seen from FIG. 2, after the pressure in the reaction system reaches 0.7mPa, the safety valve is started, the pressure in the reaction system is rapidly reduced, the safety valve is slowly closed, the pressure in the reaction system gradually increases to 0.44mPa after a period of time, then the pressure begins to decrease, and then the pressure does not continuously increase, and the reaction is finished.

The curve of the pressure in the bleed material collection tank as a function of temperature is shown in fig. 3. As can be seen from fig. 3, the temperature and pressure in the bleed material collection tank gradually increase with the entry of the bleed material, the system pressure starts to decrease after increasing to about 45 ℃, and when the temperature in the bleed material collection tank before bleeding decreases, the pressure significantly increases, indicating that non-condensable gas is generated in the bleed material collection tank.

And observing the generation of other liquid-phase substances insoluble in the inert liquid medium silicone oil in the discharged material collecting tank, wherein the discharged material contains both gas and liquid and belongs to a two-phase flow state discharged flow.

[ example 3 ]

The test of the flow state of the polymerization reaction runaway bleed material of the vinyl acetate is carried out according to the conditions and the steps of the embodiment, and the specific steps are as follows:

1. setting the automatic opening pressure of a safety valve at the top of the reactor to be 0.2MPa and injecting inert liquid medium silicone oil into a discharged material collecting tank because the out-of-control process of vinyl acetate polymerization reaction is violent;

2. mixing vinyl acetate and methanol according to the mass ratio of 9:1, adding the mixture into a reactor, adding azodiisobutyronitrile accounting for 0.1% of the mass of the vinyl acetate as an initiator, wherein the filling coefficient is not more than 60%, heating at the heating rate of 1.0 ℃/min to 60 ℃, stopping heating, keeping the system in an adiabatic state, gradually increasing the temperature and the pressure of the reaction system, starting a safety valve when the pressure reaches the discharge pressure of a safety valve at the top of the reactor to 0.2MPa, and enabling the discharge material to reach a discharge material collecting tank through a discharge pipeline;

3. the pressure of the reaction system in the reactor as a function of time obtained by the test is shown in FIG. 4.

As can be seen from FIG. 4, after the pressure in the reaction system reaches 0.2mPa, the safety valve is started, the pressure in the reaction system is rapidly reduced, the safety valve is slowly closed, the pressure in the reaction system gradually increases to 0.96mPa after a period of time, then the pressure begins to decrease, and then the pressure does not continuously increase, and the reaction is finished.

The curve of the pressure in the bleed material collection tank as a function of temperature is shown in fig. 5. As can be seen from fig. 5, the temperature and pressure in the bleed material collection tank gradually increase with the entry of the bleed material, the system pressure begins to decrease after increasing to about 55 ℃, and when the temperature in the bleed material collection tank before bleeding is reduced, the pressure does not rise significantly, indicating that no non-condensable gas is generated in the bleed material collection tank.

And observing the generation of other liquid-phase substances insoluble in the inert liquid medium silicone oil in the discharged material collecting tank, which shows that only liquid substances exist in the discharged material and belong to the discharged flow in a single-phase flow state.

At present, in most researches on chemical reaction runaway safety relief, a conservative two-phase flow calculation method is mainly adopted for determining a flow state, the relief area required by two-phase flow relief is often much larger than that required by one-way flow relief, sometimes, the calculation result is unreasonable, the calculated relief caliber even exceeds the diameter of a pressure container, and great troubles are caused to the design of the pressure container and a safety relief device of the pressure container. The invention determines the flowing state of the discharged material in the container (or equipment) by an experimental test means to obtain the conclusion of single-phase flow, the required discharge area can be greatly reduced, and the size and the cost of a downstream discharged material collecting and processing system can be effectively reduced.