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After the thermal oil boiler diesel burner is filled with new oil, it is a relatively dangerous stage in the operation of the boiler diesel burner. Therefore, special care must be taken during the process of heating, and there will be some impurities in the newly added oil. If it is not separated and removed, it may cause danger in the subsequent operations. Therefore, it is necessary to remove the light components and water in the oil at this time, so that the oil meets the operating standards, and this process is called cooking oil. So let's briefly introduce it below. The key to the quality of heat transfer oil. Excellent heat transfer oil is firstly determined by the quality of the base oil used for the production of heat transfer oil. Choosing structurally stable saturated hydrocarbons as the base oil to produce heat transfer oil can effectively avoid the rapid deterioration of heat transfer oil and prolong the life of the heat transfer oil. There are many reasons for the deterioration of heat transfer oil, but the most important ones are pollution, thermal cracking and oxidation. Pollution: The presence of impurities will accelerate the rate of deterioration of the heat transfer oil and prevent the heat transfer oil from being contaminated by impurities. Just wash the furnace carefully before changing the oil and prevent mechanical impurities, moisture and other impurities from mixing in during storage, transportation and use. Oxidation: Air infiltration into the system will cause oxidation of the heat transfer oil, and the oxidized heat transfer oil will form a large amount of solid dirt. Usually the infiltration of air comes from an open expansion tank. The heat transfer oil is oxidized to a certain exposed area and temperature. Corrosion products and rust are often due to the rate at which insolubles are formed. The rate of formation depends on the weak acid formed by the heat transfer oil in the air oxidation products and the moisture entering from the expansion tank or other parts. The mixture of the deterioration products of the heat transfer oil and the oxidized heat transfer oil insoluble matter will deposit on the surface of the heat exchanger, especially the low flow rate part of the system such as the dead corner or the lowest point. Thermal decomposition and aging coking: The thermal decomposition of heat transfer oil is caused by the use temperature of heat transfer oil exceeding its thermal decomposition limit temperature. For example, where the heat flow strength is too large or the fluidity is restricted, the cracking of the heat transfer oil often occurs, and the thermal decomposition of the heat transfer oil often causes the heat medium furnace tube to coke. In heat transfer oil contaminated by decomposed antioxidants and impurities, coking is more rapid. The formed coke adheres to the pipe wall, affecting heat transfer, and further accelerating cracking, condensation and coking, causing a vicious circle. A large amount of coke accumulates on the furnace tube wall, directly affecting the safety of the furnace body. The cracking rate of heat transfer oil increases rapidly with the increase of temperature, and the cracking speed of heat transfer oil doubles for every 10 increase in temperature. The classification of heat transfer oil is based on the composition and manufacturing process. The heat transfer oil can be pided into generation heat transfer oil, mineral heat transfer oil and synthetic heat transfer oil. The key types are the following categories: 1. Alkylbenzene type (benzene ring type) heat transfer oil This type of heat transfer oil is a kind of chemical substance with benzene ring with branched chain of ethane. It should be a substance in which short-chain branched ethyl groups (including methyl, ethyl, and isopropyl) and benzene ring are fused. Its melting point is 170~180℃, and its freezing point is below -80℃, so it can be used as engine coolant. The characteristic of this type of product is that it is not prone to precipitation in the application field, and isopropyl chain-attached chemical substances are particularly preferred. . 2. Alkyl naphthalene-type heat-conducting oil The structure of this type of heat-conducting oil is a chemical substance connected with ethane branches on the benzene ring. The additional side chains usually include methyl, dimethyl, isopropyl, etc. The type and total number of additional side chains determine the characteristics of the chemical substance. Alkyl naphthalenes with a single side chain attached to a methyl group are used in gas-phase heating systems in the range of 240~280℃. 3. Alkyl biphenyl type heat transfer oil This type of heat transfer oil is a kind of chemical substance connected with alkyl branch chains on the biphenyl ring. This is composed of short-chain alkyl groups (ethyl, isopropyl) and biphenyl ring closely combined. The type and total number of alkyl groups determine its characteristics. The greater the total number of ethane groups, the worse the heat resistance. Among these products, the thermal oil produced from meta-isomers, focal isomers (isomers) and biphenyl of isopropyl group is of the most suitable quality. Its melting point is >330℃, and its heat resistance is also good. Dream product for application within the range of 300~340℃. 4. Biphenyl and diphenyl ether low-melting compound type heat transfer oil This type of heat transfer oil is biphenyl and diphenyl ether low-melting compound composed of 26.9% biphenyl and 73.9% diphenyl ether. The melting point is 12°C. The first heat transfer oil to generate aromatic hydrocarbons in the world is Dowtherm. Its characteristics are good heat resistance and high application temperature (400°C). Since the benzene ring is not connected to the ethylene side chain, this kind of commodity has the best temperature resistance in the inorganic heat carrier. This kind of low melting point (12.3°C) compound is used in the tertiary industry when the boiling temperature is in the range of 256~258°C at room temperature. This is caused by the high melting points of the two organic compounds (biphenyl is <71°C, diphenyl ether <28°C). In the vapor process produced by the volatilization of such low-melting compounds, there is no such component enrichment, and the liquid characteristics will not change. Because diphenyl ether is fused with ether organics, long-term use at high temperatures (350°C) will cause phenolic organics. This organic matter has low irritation and has the necessary etch effect on alloy steel with moisture. Reasons for the deterioration of heat transfer oil The type and specification classification of heat transfer oil was mentioned in the previous issues. I wonder if my friends have read it. Some friends sent private messages to the editor asking many questions about the use of heat transfer oil. So today we answer one of the reasons for the deterioration of heat transfer oil: There are many reasons for the deterioration of heat transfer oil, but the main ones are contamination by impurities, thermal cracking and oxidation. The first point of pollution: the generation of impurities will speed up the deterioration of the heat transfer oil and avoid the heat transfer oil from being contaminated by impurities. Only wash the furnace carefully before changing the oil, and avoid mechanical impurities, moisture and other impurities in the process of storage, transportation and use. . The second point of oxidation: the infiltration of air will cause the oxidation of the heat transfer oil, and the oxidized heat transfer oil will produce a lot of solid dirt. This will cause the heat transfer oil to deteriorate and affect its use. The third point is thermal decomposition and aging coking: The thermal decomposition of heat transfer oil is caused by the use temperature of heat transfer oil higher than its thermal decomposition limit temperature. The thermal decomposition of heat transfer oil often causes coking of heat medium furnace tubes. As soon as the heat-conducting oil is coked, the heat conduction effect begins to decline, aging and failing, which endangers the mechanical strength. In severe cases, the oil pipe bursts and leaks/explodes, endangering personal safety. For this reason, the heat transfer oil should be replaced immediately when it deteriorates. The purpose of cooking oil 1. Make relevant staff proficient in relevant cooking oil technology so as to facilitate the normal operation of daily work. 2. Remove light components and moisture in the heat transfer oil, avoid oil pollution and oil deterioration, and make the oil work normally. Conditions for cooking oil 1. All parts of the heat-conducting oil furnace light oil burner are safe and can operate normally. 2. After the heat transfer oil system is washed with water, check that there is no leakage. All related systems have been purged and replaced. 3. After inspection and confirmation by relevant technical personnel, it is determined that it has the conditions for safe cooking. Points to note when cooking oil 1. Strictly control the heating rate, and do not allow large adjustments to the outlet temperature of the oil furnace to prevent sudden boiling of the heat transfer oil and cause oil spills in the expansion tank and oil storage tank. When the heat carrier heats up to 200°C or higher, a comprehensive inspection of the heat carrier furnace and the entire heating system should be carried out, and all the connecting bolts should be thermally tightened once to eliminate leakage caused by uneven expansion. 2. Pay attention to the pressure changes at the inlet and outlet of the oil furnace, and ensure that the heat transfer oil circulates well at high temperatures. 3. Pay attention to the liquid level of the high tank at any time, and replenish the heat transfer oil in the high tank in time, and the oil outlet temperature shall not exceed the allowable working temperature of the heat transfer oil. 4. Avoid excessive flames and direct flames against the furnace tube to prevent excessive temperature. 5. Generally, different brands of heat transfer oil should not be mixed. 5. Pay attention to safety when igniting. Don't injure people and cause the fire to burn outside the furnace, causing fire. For cold furnace ignition, the hot oil circulation pump must be turned on before ignition. 6. It is strictly forbidden for the operator to leave the site before the fire is not burning normally, and the lubrication points of the machinery should be filled with oil according to regulations. 7. When the heat-conducting oil is heated to 105-130℃, the exhaust volume is the largest. When there is a large amount of gas, the furnace temperature can be appropriately lowered to prevent the mixture of heat-conducting oil and water from being discharged from the exhaust pipe of the upper tank. 8. Make a record of cooking oil. The oil cooking process of the heat-conducting oil boiler diesel burner 1. Start the oil injection pump and drive the external heat-conducting oil into the high-level expansion tank. Until the expansion tank low level warning light goes out. 2. Start the heat-conducting oil circulating pump and circulate the heat-conducting oil in the system in a cold state for at least four hours. After the heat-conducting oil in the system is completely circulated, turn on the heat-conducting oil burner light oil burner. 3. The temperature is increased to 50 degrees at a rate of less than 5 degrees per hour, and then to 80 degrees at a rate of less than 1 degree per hour; and then to 105 degrees at a rate of less than 1 degree every two hours. 4. When the heat-conducting oil temperature reaches 100 degrees, the system maintains a constant temperature, enters the dehydration and exhaust phase and the maximum heat-conducting oil temperature cannot exceed 130 degrees. This stage takes 36 hours. (Note: Whether the degassing process is completed or not is marked by the stable outlet pressure of the hot oil circulating pump when the temperature of the heat transfer oil is 120-130 degrees). 5. After the previous stage is over, continue to heat up to 150 degrees at a rate of no more than 2 degrees per hour, and maintain this stage for at least 10 hours. 6. When the temperature of the heat transfer oil reaches 150°C, the system starts to heat up to 180° at a rate of no more than 12° per hour, and the heat transfer oil reaches the conditions for commissioning. 7. The oven temperature is subject to the oven outlet temperature. If the temperature exceeds the specified temperature at a constant temperature, it can be properly compressed. If the oil emission occurs during the oil cooking process, the operator did not directly adjust the burner to normal operation according to the relevant requirements in the installation and operating instructions, and the oil temperature rose sharply to 180°C, which caused the high oil level of the boiler diesel burner. The overflow speed of the expansion tank overflow pipe is blocked, and the moisture in the heat transfer oil volatilizes directly from the exhaust pipe to spray the heat transfer oil to the top of the boiler diesel combustion engine room, and then flows to the entire boiler diesel combustion engine room on the ground, causing a major accident hazard , Will bring great economic losses to the enterprise. How to avoid the normal operation of the organic heat carrier boiler diesel combustion engine during the oil boiling process depends on the correct debugging of the entire system of the burner and the organic carrier furnace, which is to check the installation quality of the boiler diesel burner and the thermal cycle of the boiler diesel burner The key to system stability. Through debugging, the operating skills of the firemen can be improved to ensure the safe and economic operation of the boiler diesel burner. Therefore, the commissioning of the boiler diesel burner should involve the professional staff of the boiler diesel burner installation and construction unit and the user's operator. During the commissioning process, the operating conditions of the boiler diesel combustion engine should be measured and carefully recorded to determine whether the boiler diesel combustion engine thermal cycle system is operating normally. The debugging of the boiler diesel combustion engine is pided into pre-commissioning preparation, pre-ignition debugging and debugging under the hot state of the boiler diesel combustion engine. Before commissioning, the preparations should be carried out according to the following requirements: 1. Do the installation and acceptance of the boiler diesel burner and pass the acceptance; 2. All connecting pipes should be firmly installed, safe and reliable, and sufficient and reasonable in thermal expansion; 3. Demolition pressure test The blind plate used at the time, completely remove the debris in the pipeline system, oil storage, flue duct, expansion tank, furnace, etc.; 4. All pipeline valves, automatic regulators and various dampers should be opened and closed flexibly and reliably. The blue connection should be tightened; 5. The electrical system should be constructed according to the drawings, and the instruments and meters should be installed according to the technical specifications; 6. Whether the manual rotation transmission mechanism has mechanical jams and stagnation failures, and the transmission mechanism should be filled with lubricant according to the instructions; 7. All instruments and protection devices are qualified for debugging; 8. Relevant departments and professionals shall conduct a comprehensive inspection of the above-mentioned work, make detailed records and accept the acceptance; 9. Formulate emergency preparedness plans and personnel operating procedures. ! 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