Risk analysis and prevention of the hottest therma

Risk analysis and prevention of thermal power plant

1 Fire risk hidden danger

thermal power plant is the place where the chemical energy of fuel is finally converted into electrical energy. There is a fuel combustion process in the middle, so the fuel is easy to cause fire. The coal, coal handling system and pulverized coal dust in coal-fired power plants, as well as the fuel oil and gas in oil-fired and gas-fired power plants may cause fires and explosions. In addition, various lubricating oils are widely used in large-scale equipment of thermal power plants, which have the risk of leakage. There is also a hydrogen cooling system available for generators, which may also cause fire accidents

2. Possible losses

serious leakage, imperfect alarm monitoring system or ineffective fire extinguishing system may cause the usable damage of main equipment, and even the burning of the whole plant

3. Fire risk prevention and control measures and evaluation contents

the layout of the plant, the layout of machinery and equipment, whether the monitoring system works normally, whether the fire extinguishing system can effectively extinguish the fire under special circumstances, and whether the overall safety management of the thermal power plant is in place are all the evaluation of fire risk 4 Check whether the insurance on the socket of the ring stiffness tester is an effective basis for burnout insurance

(II) explosion risk

1 Both steam turbine units and gas turbine units have high temperature and high pressure conditions, and both use high temperature and high pressure working medium, which has great explosion risk. Because the high temperature and high pressure section itself is a key part of the key equipment of the thermal power plant. If the explosion power is huge, it may cause extremely serious consequences. Later, it realizes the versatility of the universal experimental machine and brings huge losses. In addition, there are explosion risks in pulverized coal dust of coal-fired power plants, oil storage tanks of kerosene power plants, gas supply systems of gas power plants, and hydrogen cooling systems in generators and other equipment

2. Possible losses

boilers, steam turbines and gas turbines all have the risk of explosion. If the situation is serious, it will not only cause total damage to the equipment itself, but also the explosion may damage the plant and even the buildings or equipment around the plant

3. Explosion risk control measures and evaluation contents

thermal power plants monitor physical parameters under various working conditions through a large number of sensors. Once these parameters are found to be abnormal, they immediately enter the protection state, cut off relevant equipment or carry out relevant protection treatment to avoid accidents. Therefore, whether the monitoring system of thermal power plants is normal and whether the internal management of power plants is perfect is an important basis for evaluating the magnitude of explosion risk

(III) machine damage insurance

1 The possible maximum loss of machine damage insurance in thermal power plants is generally less than that of property insurance, because the loss of machine damage insurance generally only involves the machinery and equipment itself, and at most only affects individual units, unless there are two or more units sharing important key equipment

2. Machine damage insurance loss cause

the machine itself has defects in design or manufacturing: the equipment works under abnormal working conditions; Workers' operation errors; In addition to the problems in design and manufacturing, other risks such as power and water outages can be effectively improved by strengthening internal management and improving the professional quality of employees

3. Common machine damage accidents

(1) coal mill damage: Coal often contains iron filings, wood blocks, stones and other substances. If the above substances are not removed before being sent to the coal mill, it is very likely to cause damage to the machine

(2) the whole turbine shaft is bent and the bearing bush is burned: the oil film is unstable, resulting in poor lubrication

(3) turbine blade damage: foreign matters such as welding slag enter

(4) large transformer damage: lightning strike or short circuit

suggestions on risk prevention of thermal power plants

(I) suggestions on fire prevention of fuel and combustion system

1 Coal

(1) the danger of coal is spontaneous combustion of coal. The simple way to prevent spontaneous combustion of coal is to improve the heat dissipation conditions of coal, and do not pile the coal too high for too long. At the same time, fire hydrants can be set around the coal yard, and there is always error pressure in rolling the coal pile regularly, so as to reduce the internal air, so as to effectively prevent spontaneous combustion of coal due to oxidation and heat release

(2) before coal is sent to the coal mill, special equipment should be set to remove iron filings, stones, wood blocks, etc

2. The fuel oil storage tank area

should be arranged separately, away from the main re inspection results such as the main plant. When the tensile strength of one specimen is less than the specified value, the building should be more than 20 meters, and the fire dike in the tank area should be set (the dike is. 6 meters high, built with non combustible materials), equipped with sufficient fire extinguishing facilities, and the oil tank should have good grounding devices and lightning protection facilities

(1) the fuel delivery pipeline, especially the interface, should be regularly inspected and tested, and the problems found should be repaired in time to prevent fuel leakage and fire

(2) the common heating methods of the oil tank heating system are: heating at the bottom of the oil tank, plug-in heating and external circulating heating. All heaters should have devices to control the heat supply to prevent accidents caused by overheating of fuel oil

(II) strengthen the operation specifications of steam turbine generator units

1 The operation of steam turbine must strictly comply with the operating procedures. Before starting the machine, the commissioning and installation equipment, oil tank and oil pipe, oil cooler, oil pump, bearing and their joint parts shall be comprehensively inspected to meet the relevant regulations

2. Strengthen the patrol inspection and inspection of the unit, and take measures in time in case of large oil and gas leakage vibration. The water-cooled generator is not allowed to have water leakage, and the hydrogen cooled generator is not allowed to have air leakage or spark

3. The oil pipeline should be installed away from the high-temperature pipeline. The surface of these hot objects should be covered with iron sheet or glass wool cloth, painted, etc. it is strictly forbidden to heat oil products with steam in the main oil tank. In addition, the main oil tank should also be equipped with smoke exhaust devices and accident oil drainage devices

(III) fire extinguishing system

1. The control electrical room should be equipped with fixed gas fire extinguishing devices

2. Keep the main control room clean and sanitary, and do not stack combustible materials such as waste paper in the room

3. cable holes passing through walls and floors shall be sealed with non combustible materials such as asbestos, sand, concrete, etc

(IV) large power transformer (main transformer)

1. The fire separation distance between outdoor transformer and surrounding buildings should meet the following values: meters for civil buildings (grade I fire resistance rating), meters for the metric oxygen room of the power plant, 25 meters for the warehouse of dangerous goods, 50 meters for the combustible liquid storage tank area of the fuel system, and 20 meters for the oil pump room

2. When the fire separation between the outline of the oil immersed power transformer and the outer wall of the building is insufficient, the outer wall of the building should be a firewall, or when the outer wall of the building is within 5 meters from the outline of the outdoor oil immersed transformer, there should be no doors and windows and ventilation holes on the walls within 3 meters on both sides of the outline below the horizontal line of 3 meters of the total height of the transformer. Windows with non combustible frames are allowed on the walls above the horizontal line of 3 meters of the total height of the transformer

3. the outdoor main transformer shall be equipped with emergency oil storage pit or oil retaining wall according to the regulations, and be washed regularly. The oil drainage facilities must be kept unblocked