Principle of electric heating heat transfer oil boiler diesel burner

As a safe, energy-saving, low-pressure, new type of special industrial boiler diesel burner that can provide high-temperature heat energy, electric heating heat transfer oil Boiler diesel burners are used rapidly and widely. However, due to improper operation or unreasonable design, accidents may occur in the daily use of electric heating oil heaters. The following is a preliminary discussion on preventive measures for accidents of electric heating oil heat transfer furnace. The working principle of the electric heat conduction oil boiler The diesel burner of the electric heat conduction oil boiler is a kind of electric heat source. The heat conduction oil is used as the heat transfer medium. The circulating pump is used to force the liquid to circulate, transfer the heat to the thermal equipment, and then return through the special industrial furnace. Heating, so circulate, realize the continuous transfer of heat, the temperature of the heated object, and the requirements of the heating process. The electric heat conduction oil boiler diesel burner system consists of a heater, an organic heat carrier furnace, a heat exchanger, a control cabinet, a thermal oil pump, an expansion tank, etc. to form a skid. The user only needs to connect to the power supply, the medium inlet and outlet pipes and some electrical interfaces can be Put into use. Common risk prevention measures for electric heating heat transfer oil boiler diesel combustion engines 1. Prevent hidden dangers caused by the deterioration of heat transfer oil quality. Premature deterioration of heat transfer oil quality due to poor operation and production process management is the most common in electric heat transfer oil boiler diesel combustion engines One of the problems. However, the low-quality heat-conducting oil that has been running for a long time continuously increases the carbon accumulation on the pipe wall of the heating surface, and the decrease in the inner diameter of the pipe reduces the flow rate of the heat-conducting oil. Gradually increase the resistance of the circulating pump and continuously reduce the heat transfer efficiency, resulting in coking and clogging of the furnace tube, and ultimately leading to vicious accidents such as overburning, deformation, and tube bursting. One of the reasons for the deterioration of the quality of heat transfer oil is the pyrolysis of local overheating and oxidation of the heat transfer oil. If it exceeds its maximum operating temperature, the heat transfer oil will locally overheat, leading to thermal decomposition and condensation, carbon residue precipitation, lower flash point, darker color, increased viscosity, lower heat transfer efficiency, and coking aging. The heat-conducting oil reacts with oxygen in the air to produce organic acid and condense it into cement, which increases the viscosity, which not only reduces the service life of the medium, but also causes acid corrosion in the system. At present, the quality standards set by various heat transfer plants in my country are different, and the quality of the heat transfer oil produced varies greatly. For the heat transfer oil in use, the 'Regulations on the Safety and Technical Supervision of Organic Heat Carrier Furnace' stipulate that the kinematic viscosity, flash point, carbon residue and acid value should be tested at least once a year. 2. The hidden danger of automatic control system failure. At present, the current status of the current domestic heat transfer oil electric heater technology is a heat transfer oil control system with a programmable controller PLC as the control core. Under a certain temperature, the heat transfer oil will change from the working pressure of the circulating pump. From the inlet to the heater, the temperature of the heat-conducting oil gradually rises through the heating chamber of the heater, and then the required process is realized from the outlet flow, temperature and heat-conducting oil, thereby further improving the automation of the equipment. The heat transfer oil in the control system is sent to the system as a whole through a gear pump. When the magnetic double-column liquid level controller is set to reach the specified value, the pump will automatically shut down, and then the circulation pump and electric heater will be started to heat, when the outlet oil temperature reaches the set value When the value is set, it enters the user's system cycle. After the equipment uses oil again to enter the heating device, the cycle and circulation are the working conditions of the heat transfer oil. These automatic control systems are effective obstacles to ensure the safe operation of electric heating and thermal oil boiler diesel burners, and they are usually the same obstacles. 3. The hazards of air and moisture. In the new type of electric heating heat transfer oil boiler diesel burner, the oil change and maintenance process enter the air and water. During the heating process, the air expands and the moisture evaporates. The volume change is much greater than the thermal expansion of the heat transfer oil itself. When the pressure is zero, the evaporation of water expands by more than 1600 times, and the air expands by about 5 times at a temperature of about 270°C. If these air and moisture cannot be discharged in time, it will cause higher working pressure and seriously threaten the safety of the system. Therefore, the water content and other components in the heat transfer oil should be strictly controlled. During the heating start process, the exhaust valve should be opened repeatedly to remove the mixed steam of air, water and heat transfer oil in the system, and pay attention to controlling the heating speed of the heat transfer oil. 4. Potential leakage between pipe flanges or valves. Pipe flanges or valve connections are the most leaky heat transfer oil system, because heat transfer oil has the characteristics of easy penetration and combustibility, especially for porous materials, the immersion of the insulation layer is sticky. The combined force is stronger. If the heat transfer oil is not found in time, it is easy to cause a fire. Therefore, it is necessary to regularly check whether the flange and valve connection are intact, and if they are damaged, they should be replaced in time. From the thermal oil boiler diesel combustion engine to the operation process, due to temperature changes, the flanges are easy to loosen, and leakage often occurs. At this time, attention should be paid. All sealing parts in the piping system should be flexible and metal-wound products with good sealing and flame retardancy. Rubber parts should not be used. The insulating material should have low porosity and not easily impregnated by the organic heat carrier to prevent the insulating layer from catching fire after the organic heat carrier leaks. 5. Coking potential of the electric heating rod When the heating rod is used to heat the heat transfer oil, the surface of the heat transfer rod will quickly coke, and finally the heat transfer oil will be discarded. The cause of serious carbon deposition can be analyzed through heat transfer calculation: Take 220V4kW heating rod as an example, the surface area is 0.125m2, the heat transfer coefficient K = 67-114w/℃·㎡, K = 114W/℃·㎡ under natural convection. According to the calculation of Q = KF delta t, the heating rod should transfer 4kW of heat from the heat transfer oil, and the temperature difference between the rod surface and the heat transfer oil must be greater than 275°C. When the average heat transfer oil temperature is 300°C, the surface temperature of the rod must reach 575°C. The allowable film temperature (equivalent to the surface temperature of the rod here) of the heat transfer oil in the furnace tube with the highest allowable temperature of 340°C shall not exceed 370°C. Now that the hot oil is in contact with the surface of the 575℃ rod, the coking must be serious, and the hot oil life is very short. The method to prevent serious carbon deposition on the surface of the electric heating rod is to increase the surface area of ​​the electric heating rod so that the heat load on the surface of the rod is limited to an appropriate range. Through calculation, two 2kW resistance wires connected in parallel with 4kW electric heating rods are connected in series. When the terminal voltage is 220V, the total power of the resistance wire is 1kW. The surface area of ​​the heating rod is still 0.125m2, and the temperature difference required for heat transfer is 69°C. Similarly, when the average oil temperature is 300°C, the surface temperature of the heating rod is 369°C, and 1kW of heat is transferred to the heat transfer oil. 369℃ is close to the allowable film temperature of 370℃ for heat transfer oil, which can alleviate the problem of coking. The best solution is to design and manufacture special heating rods to increase the surface area and make the surface temperature lower than the allowable liquid film temperature of the thermal oil. ! If you are interested in diesel combustion engines, please contact us for a quote!