How to effectively prevent fuel injection with heat conduction oil boiler diesel burner

With the continuous improvement of my country’s boiler diesel burner manufacturing technology, the boiler diesel burner industry has gradually changed from the traditional old steam The boiler diesel burner has successfully transitioned to the stage of thermal oil boiler diesel burner. Compared with the traditional boiler diesel burner, its thermal efficiency has been greatly improved, and it also has excellent performance in environmental protection. However, many people may find that fuel injection occurs when using the heat transfer oil burner light oil burner. This is a more dangerous situation. Then we will briefly introduce the fuel injection situation of the boiler diesel burner. Classification of heat transfer oils Heat transfer oils can be pided into two categories: 'mineral oil type' and 'synthetic type' according to the production process and the molecular structure of the substance. Mineral oil is made from petroleum as raw material, through distillation and refining (including solvent refining and hydrorefining) process to obtain appropriate distillate base oil, mixing functional additives. The molecular structure of the main components of the base oil is pided into a mixture of alkanes, cycloalkanes and aromatic hydrocarbons. Mineral oil has a wide range of raw materials, non-toxic and odorless, and has good thermal oxidation stability. It can be used in open systems, but its thermal stability is relatively low. Generally, the maximum allowable use temperature is not higher than 320℃. Synthetic oil is a product with a certain chemical structure and a certain chemical name produced by a chemical synthesis reaction process. Synthetic heat transfer oil is pided into two types according to the maximum allowable temperature: ordinary synthetic type and synthetic type with special high thermal stability. The maximum allowable operating temperature of ordinary synthetic type is below 320℃ (including 320℃), and the maximum allowable temperature range of synthetic heat transfer oil with special high thermal stability is 330~400℃, which is L-QD type. Synthetic heat transfer oil has good thermal stability, long service life, and renewable, but it is expensive and partly depends on imports. The chemical structures of these substances include synthetic aromatic hydrocarbons, alcohols, ethers, esters, silicone oils, and chlorinated hydrocarbons. But it should be noted that not all synthetic products are better than mineral oil products. The thermal stability of some ordinary synthetic products is even lower than that of mineral oil products. For example, some of the more popular heat transfer oils of foreign brands on the market are the bottom by-product of synthetic detergent raw material dodecylbenzene. Boiling material (or weighing alkylbenzene), its maximum allowable temperature is only 300℃, it is L-QB300 heat transfer oil, and some brands require use in closed system due to unqualified oxidation stability. Why does the heat-conducting oil boiler diesel combustion engine have oil injection during the heating process? This indicates that your machine is an open device and there should be no circulation system. Electric stove, sandwich pot, etc. As for the oil injection, there are only two cases. The heat transfer oil contains water. The water temperature is about 100, and the water density is greater than that of the heat transfer oil. So underneath, when you heat it, the water will expand and it will be like a wok oil and water mixture. The same bang. If there is little water, it is recommended to evaporate slowly at a low temperature of about 100 degrees. If it is used normally, if it is more, before emulsification, it must be put out for disposal before use. There is another kind of fake oil, which has a low flash point. For example, if you heat the heat transfer oil with a flash point of 180 and you heat it up to 250, this will happen. What are the general reasons for the oil injection of the heat-conducting oil boiler diesel combustion engine? 1. The oil is injected because of the moisture in the heat-conducting oil. There is no water in the closed loop system, but there is water in the upper tank. The moisture in the original circulation system enters the upper tank through the auxiliary exhaust pipe, and the temperature of the upper tank is only 60 degrees. Only a small part of the water vapor is discharged, and most of it is condensed and accumulated in the upper tank. After the temperature of the heat-conducting oil rises, the volume expands, and it is pushed into the high-position tank, and the heat-conducting oil in the high-position tank is heated to 140 degrees, and the water in it boils and sprays and sprays oil. 2. The heat-conducting oil is thermally cracked, and a large amount of light components are generated. Due to the failure of the pressure gauge at the outlet of the boiler diesel burner, a large amount of gas is actually silted in the pipeline. The noise on the site is relatively large, and the furnace worker did not notice the sound of the air hammer. When the gas accumulates to a certain amount of Chengdu, it overflows to the upper tank through the oil-gas separator, and because of the relatively high pressure, it will spray out with oil. How to prevent the installation height of the high-position expansion tank of the heat-conducting oil boiler diesel burner is based on the fact that the installation height of the high-position tank must be greater than the cavitation allowance of the pump and the saturated vapor pressure under the working state of the heat-conducting oil, but also higher than the highest hot spot, so first meet the heat transfer The cavitation allowance of the oil pump is 3 to 5 meters. Generally, the heat transfer oil with too high vapor pressure is not used for the heat transfer oil. In case of special circumstances, the vapor pressure of the selected heat transfer oil is greater than 5 meters under working conditions (ensure positive pressure operation at the inlet of the circulating oil pump ) Or the design does not use a high-position expansion tank, you can use inert gas (such as nitrogen, carbon dioxide, etc.) to pressurize and seal, adopting this measure is more beneficial to the service life of the heat transfer oil. The high-level expansion tank should be installed at the highest point of the heat-conducting oil heating system, otherwise the heat-conducting oil of the high-level heat user cannot be filled up. If the heat-conducting oil is forced to be filled up, the high-level tank will rise. In order to prevent high-temperature oxidation of the heat transfer oil, it has been proved by experiments that the temperature should not be higher than 60℃, because the oxidation of the heat transfer oil above 60℃ will increase the data. The main method to prevent high temperature is that the high-position tank cannot be insulated. The diameter of the expansion pipe must be According to the regulations, the design should not be too thick, and the distance between the high-position tank and the oil-gas separator cannot be too close, which means that the expansion pipe between the oil-gas separator and the high-position tank is relatively long, the better. Synthetic heat transfer oil is good for heat dissipation of heat transfer oil. , Of course, the pipeline cannot be insulated, and even the pipeline with a finned tube with good heat dissipation performance is more effective. The high-position expansion tank can perform multiple functions such as exhaust, oil replenishment and dehydration. 1. When the heat transfer oil is loaded into the system, the air in the system needs to be driven out. After the normal operation starts, with the extension of the operating cycle, the heat transfer oil will generate cracked gas (such as hydrogen, methane, ethane, ethylene... ...Etc.), these gases from the belt conveyor should be discharged to the upper tank through the oil-gas separator and expansion pipe at any time. The process of discharging and separating is easier because of the heat transfer oil (density 800kg/m3) and these gases (air density 1.3 kg/m3, the density of mixed petroleum gas is 18-30kg/m3). In order to prevent air resistance, expansion pipes generally do not use elbows less than or equal to 90°, and are usually used for slow-bending connecting pipes greater than 90°. This not only solves the problem of preventing the generation of air resistance, but also eliminates the thermal stress of the metal equipment pipeline. 2. Oil replenishment: After using for a period of time, the heat transfer oil will naturally lose 5-10%/year and needs to be refilled. After the liquid level of the high tank is lowered, use a charge pump to replenish the liquid from the low tank to the high tank to the normal level, generally maintaining normal temperature 1/3, when the working temperature is less than 2/3, the liquid level is normal. Otherwise, it should be suspected whether the design, installation and operation are wrong. There should be no liquid level in the high tank under any circumstances during the production process. 3. Dehydration: Because the newly installed equipment has residual water after the hydraulic test, the cooling water of the circulating oil pump jacket leaks, the heat transfer oil barrel leaks into rainwater... etc., the heat transfer oil in the system contains water, and the heat transfer oil is heating up. When (100～150℃) water suddenly vaporizes (after vaporization, the expansion volume is more than 800 times under normal pressure), causing the oil pump to evacuate, the high expansion tank sprays oil, and it is unable to continue heating and normal operation. For this reason, the vibration feeder is in the early stage of construction The heat transfer oil heating system must be dehydrated. Dehydration is a more difficult problem. In order to handle this process well, you must first understand the necessary conditions for dehydration: the temperature is 100～150℃, the heating rate and the evaporation volume are mastered, and the evaporation is large. In the surface and space, there is enough pressure head to transport the oil to the upper tank, and the exhaust port should not be too small. Related operations for heat transfer oil dehydration 1. When the heat transfer oil temperature rises to 120°C-150°C, it enters the dehydration stage. A small amount of light components will be discharged when the oil temperature rises to 200°C. At this stage, a slow temperature rise or constant temperature control water volume and Removal of light components. 2. In the dehydration process, the essentials of slowness should be mastered, and the exhaust volume of the high tank can be observed to control. 3. The temperature rise of the coal-fired thermal oil furnace is controlled at the same stage as the drying furnace. 4. After the heat transfer oil is dewatered, the temperature should be raised slowly. After the light component volatiles in the heat transfer oil are removed, it can be raised to the process temperature for normal operation. 5. When the oil temperature rises to the process temperature, check the entire system for leaks. After the inspection is completed, heat the pipes. The degassing operation of the heat transfer oil boiler diesel burner The heat transfer oil burner light oil burner is to directly insert the electric heater into the organic carrier (heat transfer oil) for direct heating, and carry out the liquid phase circulation through the high temperature oil pump to deliver the heated heat transfer oil to The heating equipment is used, and the oil outlet of the heating equipment is returned to the electric heating oil furnace for heating, forming a complete circulating heating system. If the heat-conducting oil furnace is heated by the light oil burner, the steps of ignition, heating and dehydration are as follows: 1. The initial heating stage of the heat-conducting oil heater: start the hot oil circulation pump and perform cold furnace ignition. After the cold furnace is ignited, the temperature is raised at a temperature rise rate of every 10°C/hour. Until 90～95℃. Due to the high viscosity of the oil during the cooling of the furnace, the low flow velocity in the heating surface of the pipe, the thicker oil film on the pipe wall and poor heat transfer conditions, it is easy to cause the local oil film temperature to be too high. 2. Oil heater dehydration stage: the range of 90～110℃ is the stage to drive away the residual water in the system and the trace water contained in the organic heat carrier. The heating rate is controlled within the range of 0～5℃/hour, and the length of this time depends on the dehydration situation. When the exhaust volume at the vent pipe of the high-position expansion tank is large, there is a sound of water hammer at the bottom, the pipe vibration is aggravated, and the pressure gauge pointers everywhere swing greatly. The temperature rise must be stopped and kept at a constant temperature. The length of this stage depends on the amount of remaining water and the quality of the heat carrier. Never blindly accelerate the speed of heating and dehydration, because once the water in the system violently evaporates and vaporizes, the volume will expand more than 1,000 times, which will not only cause 'bumping', cause the oil level to expand rapidly and spray out, and may cause the pressure component to rupture and cause an accident . 3. Reheating stage of the heat-conducting oil furnace light oil burner: When the noise in the pipeline of the mold temperature machine becomes smaller, the hot oil circulating pump no longer appears to be evacuated (the pump outlet pressure drops below 0.1MPa, and there is heavy gasping noise) , The temperature can be increased at a rate of 5°C/hour, but not more than 120°C, until the vent tube is no longer exhausted. 4. Degassing (degassing) stage of the heat-conducting oil heater: After the dehydration process is completed, the temperature is increased at a rate of 30°C/hour, but it should be noted that the residual water may evaporate, and the temperature should be stopped at any time. Stop when the temperature reaches 210-230°C, and then mainly remove the light components in the heat carrier. The light components in the heat carrier for liquid heating are present in the gas phase, which will cause 'air resistance' to make the pressure of the hot oil circulating pump unstable, and the flow rate will drop or be interrupted. The length of the light component removal process depends on the quality of the residual heat carrier. When no gas is discharged from the vent pipe, the pressure of the hot oil circulating pump is stable, that is, the temperature can be increased at a rate of 0-10°C/hour. Precautions for purchasing heat transfer oil Before selecting heat transfer oil and replacing new oil, if the system is already coking, you must carefully clean the system. If conditions permit, the cause of coking should be carefully found, and the problem equipment parts should be corrected. 1. Confirm the authenticity of the highest use temperature of the heat transfer oil-test at the highest use temperature to see if the appearance is transparent, free of suspended matter and precipitation, and the total deterioration rate is not greater than the temperature corresponding to 10%. 2. Confirm the evaporability and safety of the heat transfer oil-the flash point of the opening meets the requirements of the standard index. The higher the initial boiling point temperature, the less likely the heat transfer oil will vaporize, the more balanced the system temperature and pressure, and the smaller the supplement of heat transfer oil. The longer the life span; the heat transfer oil with high spontaneous ignition point is less likely to catch fire when exposed to air, and its safety is higher. 3. Confirm the depth of heat transfer oil processing and refining-the appearance is a light yellow transparent liquid, with good storage stability, and does not change color or precipitate after exposure to light. The residual carbon is not more than 0.1%, and the sulfur content is not more than 0.2%. 4. Confirm the low temperature fluidity of the heat transfer oil-select the appropriate low temperature performance according to the area where the heat transfer oil is used and the ambient temperature of the equipment. The kinematic viscosity at low temperatures (0°C or lower) is relatively low. 5. Confirm the heat transfer performance of heat transfer oil-with lower viscosity and higher density, the smaller the temperature difference between the outlet temperature of the oil furnace and the operating temperature of the equipment, the faster the flow rate of the heat transfer oil, and the better the heat transfer performance of the heat transfer oil. ! If you are interested in diesel combustion engines, please contact us for a quote!