Large-scale petrochemical enterprises fire fighting and rescue plan

With the accelerating process of industrialization, the petrochemical industry has developed rapidly. Petrochemical raw materials, finished products or semi-finished products are all flammable materials. Once a fire occurs, it is very difficult to fight. The petrochemical production process is usually accompanied by a relatively harsh environment such as high temperature and high pressure. Once a fire occurs, it poses a great threat to life. Therefore, a scientific and effective disposal plan for large-scale petrochemical enterprises is the necessary guarantee for minimizing human casualties and property losses. The author analyzes the fire and rescue characteristics of a 10 million-ton petrochemical company. Taking a ten million-ton petrochemical enterprise fire as an example, the author discusses the scientific and effective disposal methods and proposes a feasible plan for the suppression of 10 million-ton petrochemical fires.

1 million-ton oil refinery and fire fighting and rescue Features

(1) High fire heat value and fierce fire. The 10 million-ton petrochemical fire has a high calorific value and a fierce fire. The flame can rise up to several tens of meters in a few seconds. The long-term combustion can easily lead to boiling spitting and cause a large amount of combustible liquid to flow out. , and then form a larger area of ​​combustion.

(2) Burning area is large and irregular. Due to the fluidity of the liquid, the gas's ability to diffuse is stronger, which can easily lead to large-scale combustion of petrochemical fires and may cause explosions. Due to the fluidity and arbitrariness of the fluid, the ignition area becomes irregular, making it difficult to save the fire.

(3) It is easy to form a three-dimensional fire. Since the flammable substances in petrochemical plants are diffused, and the internal structures of some production facilities are mostly tall and dense, there are many vent holes left in the frame structure. When the initial fire has not been effectively controlled, It may cause the rapid spread of fire, and then the formation of three-dimensional combustion, fire fighting difficulty can be imagined.

(4) The fire fighting operation is difficult and the number of combat units is large. The petrochemical installations have many uncontrollable fires, which can easily lead to explosions, leakage of toxic gases, splashing of corrosive substances, and the formation of three-dimensional fires, surface flow fires, and high-risk secondary disasters, which seriously affect the fire fighting and rescue operations, and it is difficult to fight and dispose of fires. get on. Because of the different physicochemical properties of the burning materials, the fire extinguishing agents that need to be selected are also different: the tactical methods and fire extinguishing techniques that need to be selected are different for the equipment and the fire site. Therefore, fire fighting and rescue needs to work with professional and technical personnel, technology personnel to listen to comments and suggestions to Fire Science and Technology in October 2017, Vol. 36, paragraph 1O of the most reasonable way to develop operational plans. In the event of an explosion, gas leakage, and the formation of a three-dimensional fire, the area to be controlled and protected will increase dramatically, the amount of input will increase, and the uninterrupted supply of fire extinguishing agents at the fire site will be ensured.

(5) Large fire losses can easily cause major pollution. The petrochemical companies have a wide range of materials for production and processing, and are often flammable and explosive. Once a fire or explosion occurs, a large area of ​​poisonous and toxic gases will diffuse, which will cause serious pollution to the environment. According to statistics, the average economic loss of petrochemical enterprises is more than five times higher than that of other manufacturers. Once they are disposed of improperly, they cannot effectively control the situation at the initial stage and cause huge economic losses.

2 Fire Prevention and Rescue Design Ideas for a Ten Thousand Tonton Refinery

2 . 1 basic situation

A refinery of a petrochemical company is affiliated to China National Petroleum Corporation and is a large state enterprise. 1O May 1963 put into operation by 5O years of production and construction, developed into fuel oil, lubricating oil, paraffin wax, chemical raw materials in one large refining and chemical businesses. Refining design a processing capacity of 10 million t / a , the actual annual processing capacity of 6 million t / a . The company has 4 305 employees and 32 factory-level units , among which the main production workshop includes an atmospheric decompression plant, an atmospheric decompression plant, a heavy oil plant, a heavy oil plant, a catalytic reforming plant, and delayed coking. Workshop, hydrogenation workshop, hydrogenation second workshop, ketone body furfural workshop, gas raw material workshop, sulfur recovery workshop, wax making workshop, wax making workshop, wax deoiling workshop, etc.

2 . 2 key parts to be considered in the design of the plan

(1) Reaction-regeneration system device. The key equipments are mainly settlers, riser reactors and regenerators. The riser reactor is designed as two reaction zones, the first reaction zone temperature is 510 ~ 520 oC , and the second reaction zone temperature is 490 ~ 510 oC . In the course of long-term operation, it will cause carbon accumulation, resulting in the accident reaction temperature is too low, the heavy components in the feedstock oil can not be fully gasified, will cause the catalyst to be born with oil, causing an explosion accident. The regenerator adopts a dense-phase two-stage regeneration process with a low-pressure drop large-pore distribution plate for the scorch tank. The temperature of the regenerator is between 550 and 600 oC , and the temperature of the cauldron can not be lower than 380 °C . The regenerator is equipped with a high-temperature catalyst and flammable, explosive, and high-temperature hydrocarbon gas. Once the operation fails, the catalyst flows back, resulting in a large amount of air entering the reactor, which is prone to fire and explosion accidents. Furnace temperature is 800 oC and operating temperature is 300~400 oC . The furnace tube will experience corrosion erosion and local overheating due to prolonged high temperature. Due to the high oil and gas line speed, the furnace tube is thinned and perforated, causing fire. Or explode. If the accident goes out and gas is focused in the flue, a certain percentage of gas in a narrow space will cause an explosion. The only open flame point of the device is located in the heat source of the heating furnace. If a large amount of oil and gas leaks and spreads to the open flame area of ​​the furnace, an explosion will be caused in the pit.

(2) Key equipment for fractionation system installation. The light diesel oil and gas required for gas-liquid separation in the fractionation tower is treated by a settler. The inside of the tower is a mixture of oil and gas. Light diesel oil is extracted from the seventeenth, nineteenth and twenty-first layers of the fractionation tower at a high temperature. In high-pressure operation, the manhole gaskets are easy to age, and the equipment is easy to corrode. Corrosion of pipeline valves can cause leakage of high-temperature heavy oil, gasoline, diesel, etc. High-temperature heavy oils can ignite spontaneously. Other mediums, such as open flames or static sparks, can catch fire. The stripping column is divided into three stages for gas stripping. The light diesel oil is withdrawn from the 17th, 19th, and 21st layers of the fractionation tower and enters the stripper. The reboiler continues to heat the tower. The tower is mainly gas phase and runs for a long time. During the process, the high temperature and high pressure make the instrument and control valve unstable, and it is easy to leak. When a certain concentration is reached, it will explode.

(3) Sites that are seriously threatened by fire. First, pipelines, flanges, valves, and manhole gaskets connected to various types of tower cranes cause leakage of gasoline, diesel oil, liquid hydrocarbons, liquefied gas, and lye due to aging, corrosion of equipment, etc. In the event of a fire, a high temperature, open flame, or static spark causes a fire explosion. The second is hot oil pump room, cold oil pump room, light oil pump room, pump room in the air pump room can easily lead to seal leakage in a full fire, leakage of pipeline valves, high-temperature heavy oil naturally catches fire; gasoline, diesel, liquid hydrocarbon leak, High temperatures, open flames or static sparks cause fires. Third, heat exchangers, condensers, various storage tanks, and containers are all located near each device. Once a full-area fire occurs, fire and explosion accidents can easily occur. The fourth is the site where the threat of fire is more serious, such as the air preheater, the inlet and outlet lines connected to the atmospheric tower, the fractionation tower, flanges, valves, and any adjacent devices threatened by the fire. The inlet and outlet pipelines connected to the atmospheric pressure device are numerous. The discharge pipelines are mostly oil and gas. The flanges, valve gaskets, and pipeline elbows connected to the pipelines are operated for a long time, and it is easy to accumulate materials to form corrosion piercings, which are prone to leakage. The area is prone to fire in the event of fire. Fifth, the air preheater heats the air with the constant first, constant four, and often five lines as the heat source. The air preheater will cause the oil in the tube bundle to solidify due to the low temperature, and the hot oil can easily be ejected from the pipeline during the defrosting operation. Splashed on high-temperature pipeline caught fire. Sixth, the atmospheric pressure device frame platform is too close to the atmospheric tower and fractional distillation tower ( 5 to 8 m apart and there is a channel connection ) . When a full-area fire occurs, materials that splatter or leak easily spread to form a streamer fire. Threats to the heat exchangers and condensers on the frame platform caused a fire explosion. Seventh, external air enters the tower, forming an explosive mixture with high-temperature oil and gas and causing explosion combustion.

2 . 3 Oil refinery fire fighting and rescue design principles

(1) Strengthen familiarity with petrochemical enterprises. To do a good job in firefighting and rescue work, the first is to continuously improve the fire-fighting and rescue plan and to familiarize with drills, and to grasp in detail the basic materials of the petrochemical enterprises and their potential for large-scale fire hazards. The second is to organize rescue drills in a rational manner so that the professional quality of personnel and the use of equipment and equipment can reach the best state and the best performance can be achieved at the crucial moment.

(2) According to the fire characteristics of petrochemical enterprises, a rescue plan shall be formulated according to local conditions. First, it should be the first time to effectively save people and control fires, cooling and suppressing explosions to protect personal safety as the primary goal. Effective use of the water supply group ensures that the fire site will continue to provide water supply for a long period of time without interruption. Second, in peacetime preparations for combat training, Based on the largest, most difficult, and most unfavorable circumstances, the organization of this level of personnel to carry out training, strengthen the organic combination of people and equipment, and strive to play its greatest role in the fire.

(3) Improve the self-rescue capability of the unit itself. The important characteristics of the 10 million-ton petrochemical fire are the large fire, rapid development, and wide range. These are very urgent requirements for rescue time. Before the fire rescue force arrives, 442 units must have their own self-rescue capability. To the suppression and control of the fire, strive to get time for the fire brigade to reach the rescue.

(4) Adequate power mobilization and accurate equipment configuration. For the fire suppression of 10 million-ton petrochemical fires, it is necessary to mobilize enough high-spray trucks, high-power water tankers, foam cars, mobile bubble foams, mobile water cannons, chemical protective clothing, and heat insulation clothes in the shortest possible time when a fire occurs. , non-sparking tools, plugging and other equipment and fire extinguishing agents to ensure the rescue and rescue needs.

(5) Reasonable security protection. In petrochemical fires, explosions, collapses, high temperatures, and poisonous gases are the most serious hazards. Therefore, the safety protection during fire extinguishing is an important prerequisite for the orderly conduct of rescue work. In the parking position and the way to fight against the fire, a unified command must be made. When parking, the front of the vehicle must be oriented in a direction for easy retreat, so that the terrain can be fully utilized for screening, and the reasonable cooling device is also dangerous for explosion. The equipment does not ask for cooling.

3 Special Design Scheme for Fire Rescue of a Refinery

3 . 1 Identify the fire and ensure the focus

(1) According to the fire-fighting and rescue plan or the alarm condition, the advantaged force capable of extinguishing fire and fighting hard under heavy smoke, toxic gas, and high temperature conditions will be rapidly assembled to the fire.

(2) Identify the precise location of the combustion, the nature and quantity of the combustion materials, whether there is a danger of explosion, whether there is a trapped person, or whether the building ( apparatus ) is heated and there is a danger of collapse, the spread of fire and the direction of oil and gas flow (diffusion) direction, the fixed fire fighting facilities linkage, the control situation. To predict the development trend of fire, in the case of not having a strong fire extinguishing condition, the interception and spread, cooling and explosion protection should be regarded as the key to ensure the safety of important devices and explosion-risk equipment.

(3) When the fire starts, it is necessary to give full play to the role of an enterprise's full-time firefighting team and strive for time for firefighting units to perform firefighting and rescue operations.

3 . 2 Make full use of factory fixed fire-fighting facilities

When setting up a refinery plant in a petrochemical plant area, not only necessary fire protection facilities should be installed, but also appropriate fire fighting facilities should be set up according to the scale of the refinery equipment, the fire hazard, and the plant area and the adjacent fire fighting power. A sufficient amount of fire extinguishing agent. For example, Dushanzi Petrochemical Company has a 3 million t / a straight-run diesel hydrogenation unit, equipped with 7 underground fire hydrants, distributed around the periphery of the unit, fixed 6 fire hoses , fire hydrant and high-pressure fire water cannons ( mainly serves important Equipment and Structure ) , with a service radius of about 40 m , can completely cover the device within 40 m All the following equipment and process facilities. 40 m for new devices The above equipment and facilities will be covered with high-pressure fire spray spray facilities. In order to improve the self-rescue capability of the device, a sufficient number of portable fire extinguishers and cart-type fire extinguishers are installed in the device operating area, which can be used on the spot for emergency use. According to the actual conditions of the device, a sufficient number of hose stations are installed in the interior so that the possible leakage points are within the coverage of the fire-extinguishing steam hose. The columns of all structures and pipe bridges in the installation, and the skirts of towers and vertical containers shall be in accordance with the fire resistance limit of not less than 1 . The 5 h requirement sets the fire-retardant layer. The bottom of the air cooler is laid with a thin steel sheet to protect the underlying equipment. All structures and platforms should be provided with no less than two accesses to the ground to ensure that internal personnel can safely evacuation. Oil seal wells should be provided with oil seals to prevent the spread of fire. Fixed fire-fighting facilities include electronically controlled guns installed on platforms such as atmospheric and vacuum decompression, as well as automatic spray systems installed on the top of raw material tanks and devices. The equipment platform, frame structure, and thermal oil pumping rooms should be equipped with steam fire-extinguishing facilities.

Fixed fire-fighting facilities should be inspected regularly to ensure good use. This is a major measure and measure when fighting fires and controlling the development of fire. Fixed fire-fighting facilities have features such as quick start, easy operation, and high power. If used properly, it can control the development of fire in a timely manner, make up for the lack of strength in the first time, and not enough mobile fire-fighting equipment. The fixed fire extinguishing facility is simple in operation and practical. The staff of the plant can be operated after training. Making good use of the fixed firefighting facilities can often make us passively active, control the fire in the shortest time, prevent explosions, and win time for the fire fighting and rescue attack. , Grasp the initiative in firefighting operations.

3 . 3 Give priority to fire extinguishing methods

While cooling and extinguishing the fire, through the technical guidance and cooperation of refinery engineering and technical personnel, the use of valves to shut off the material, step-down, diversion, stop heating, stop the furnace purge pipeline and other measures to implement the process of fire fighting.

(1) shut off the valve. Based on the principle of fire extinguishing, the combustion must have flammable substances. By reducing the combustible materials in the combustion device and interrupting the supply of combustion materials, the purpose of burning can be achieved.

(2) Plugging method. While implementing omnidirectional cooling of refinery production facilities, efforts should be made to seal leaks at the leak site. Plugging is based on the specific conditions of the leaking device, matching the plugging tools and plugging glue.

(3) transfer of law. This method is mostly used for flammable and explosive liquid objects. The materials in the igniting device are introduced into the safety storage tank through the safety device, reducing the combustible material stock in the igniting equipment and reducing the internal pressure of the igniting equipment. It should be noted that the application must be applied in case of fire. The flammable and explosive liquids that are discharged in an emergency manner are all at boiling point temperature. When opening and diverting the valve, attention should be paid to the speed of diversion. Improper handling can easily lead to flash explosion.

(4) The torch is vented. This method is based on the principle of isolation and fire extinguishing. The torch is vented to the main pipe, which is connected to the safety valve and vent on the fire equipment. Part or all of the fuel is ignited. The use of non-combustible gas is used to actively control the igniting rate of the combustible gas and ensure the fire. The internal pressure, temperature, and process parameters of the equipment do not change drastically to prevent physical explosions.

(5) Mix fire extinguishing. The principle of heat conduction is used to reduce the temperature of the igniting substance to achieve the effect of cooling and extinguishing the fire. A certain amount of the same cold material or incombustible substance is injected into the device from the bottom of the device, and the substance in the device is agitated up and down, so that the high temperature material in the upper layer is cooled and exchanged with the low temperature material in the lower layer. The temperature is reduced to below the ignition point, achieving Nil- fire.

(6) System replacement. According to the condition that combustible substances need to be burned with sufficient combustion-supporting substances, inert gas, water vapor, etc. are used to completely replace flammable and toxic gases in the combustion equipment. This method is mainly applied to enclosed factories, containers, and places where air does not circulate. When high-temperature equipment catches fire, the use of steam for fire extinguishing works best. It should be noted that, after the fire is saved, it is necessary to purge the cooking equipment to steam, eliminate the dangerous situation, avoid the occurrence of dead spots in the equipment, and cause backfire and secondary explosion.

(7) Material circulation. The fire extinguishing method used when the explosion causes #l't41~ vent line, valve, flange loss, system loss of pressure relief capability, or material transfer and other means. Material fire extinguishing method may be adopted, and the material circulation process may be used to gradually reduce the temperature of the combustion device, and the method of circulating cooling may achieve the fire extinguishing effect. It should be noted, always concerned about the burning Fire Science and Technology 2017, Vol. 36 1O month as scheduled burn internal pressure device to prevent tempering explosion fire when using this method.

(8) Adjust the process parameters. For the relatively complete equipment of the chemical equipment of the fire, the adjustment of the specific parameters of the production is used to control the severity of the reaction so that the fire can be reduced and extinguished. The parameter control mainly has three means of controlling flow, temperature and pressure.

3 . 4 kinds of fire extinguishing forces coordinated combat

The general rule for the major fires of the rescue and refining equipment is: the joint action of the local enterprises, the coordinated operations, and the role of regional joint defense. The squadron in the area of ​​responsibility is first deployed, and the reinforcement squadron is quickly concentrated; the squadron in the area of ​​responsibility is close to the fire site, familiar with the situation, and plays an important role in controlling the spread of the fire in the initial stage of the fire of the refining plant; after the reinforcements arrive on the scene, they must accept the task and obey the command for the first time. , Clear responsibility for the division of labor, carry out close combat storms, and deploy effective forces to play a role in three-dimensional fighting. In the course of coordinated actions, once a sudden situation occurs and the fire form changes drastically, the subordinate commanders should actively seek contact with their neighbors and superiors, report the situation at the first time, and make correct judgments in conjunction with the operations of the joint operations unit to ensure uninterrupted operation. Collaborative action.

3 . 5 Tactics of Combination of Attack and Defense

The main attack is to strengthen the commander’s awareness of extinguishing the fire, to eliminate the fire extinguishing force as the ultimate goal, and actively adopt an offensive method of warfare. After a quick and accurate judgment of the fire, the fire that can be concentratively eliminated in one fell swoop must be quickly resolved. Deploy troops and quickly eliminate them. In the course of implementing this principle, it is required to fight fast breaks, fight close combat, and form a real offensive. To prevent supplementation means that when the fire fighting power is insufficient or waiting for the timing of fire extinguishing, the principle of extinguishing is to be actively defended. The fire of the refinery equipment is complicated and changeable, and the firepower of the field is not enough to organize an effective attack to extinguish the fire. It is necessary to focus on the strength of the presence to protect the key points, open up the offensive route, wait for reinforcements to arrive at the scene, and when the timing of the offensive is ripe, turn it back to attack.

When fighting a fire in a refinery, it is necessary to correctly understand the dialectical relationship between offense and defense. According to the situation of the fire, the offensive and offensive should be carried out. The code should be observed and the combination of offensive and defensive fire fighting principles should be adhered to. In the field of refining equipment fire, emphasis on attacking tactical awareness, but in the offensive at the same time to do a good job of ideological preparations, once the attack fails, we must promptly withdraw, take defense, to prepare for the next attack and create conditions.

4 Conclusion

Extinguishing fires in petrochemical installations is a difficult and important task for fire fighting teams in firefighting and rescue work. It is also a key point for equipment and tactical requirements, high professionalism, and sudden uncontrollable situations. Reasonable use of equipment and tactics, multi-party cooperation, and close cooperation are the winning weapons for success. The rational allocation of combat strength is the theoretical support for equipment and tactics. How to better exert the subjective initiative of the personnel, how to maximize the effectiveness of the equipment, and ensure the effective implementation of the tactical tactics is the focus of our research. The fire-fighting combat forces that can be mobilized for the first time to increase the familiarity and research efforts for the petrochemical installations, equipped with fire-fighting equipment, and the tactical measures to be utilized, lay a solid foundation for actual fire fighting.

This data from the "fire and rescue command", Author: Song the male.