Most people may already know something about flue gas waste heat recovery, because they have already explained a lot about it. In order to let you know the relevant knowledge of flue gas waste heat recovery, the following is a brief introduction to the two methods commonly used for recovery. Guangdong Steam generator Two methods are usually adopted for flue gas waste heat recovery: one is to preheat the workpiece; The other is to preheat air for combustion support. The flue gas preheating workpiece needs to occupy a large volume for heat exchange, which is often limited by the operation site (this method cannot be used for furnaces that are used intermittently). small-scale Steam generator factory Preheating air for combustion support is a good method. It is generally configured on the heating furnace, which can also strengthen combustion, speed up the temperature rise of the furnace, and improve the thermal performance of the furnace. This can not only meet the requirements of the process, but also achieve significant comprehensive energy-saving effect.

The existing industrial boiler flue gas waste heat recovery equipment mainly includes tubular heat exchanger and full heat pipe heat exchanger. Tube and tube heat exchanger can be composed of finned tube bundles. The advantage of finned tube is that it can withstand higher temperature, but has low heat transfer coefficient and large floor area. Guangdong Steam generator The flue gas of industrial boilers contains sulfur and other acidic substances. In the low temperature zone (flue gas outlet section), the temperature may be lower than the dew point of the acidic substances. The acidic substances will dew on the pipe wall, corrode the shell of the fin tube. The fin tube heat exchanger has poor operating reliability and low service life. small-scale Steam generator factory The total heat pipe heat exchanger of boiler flue gas waste heat recovery equipment is composed of heat pipe bundles. Its shell is made of multi-layer composite materials. The heat pipe structure is complex, the cost is relatively expensive, the service life is short, and the steel consumption is large. It is difficult for users to accept it, and it is difficult to promote its application in production. The composite heat pipe heater not only takes into account the heat exchange effect, but also takes into account the economic affordability of the investors in production, which is particularly suitable for the current situation in China's industrial production.

After the cold furnace of oil fired and gas fired boiler is ignited, the speed of temperature rise shall be controlled at 10 ℃/hour, mainly because the viscosity of oil temperature is large when it is cold, and the flow rate in the heating surface pipe of the whole equipment is relatively low. Guangdong Steam generator The oil film on the pipe wall is thick, so the heat transfer condition is poor when in use. If the heating speed of oil and gas fired boiler is too fast during use, it is easy to make the local oil film temperature too high. The equipment is in the stage of driving away the residual moisture and moisture contained in the heat conduction fluid in the system within the temperature range. small-scale Steam generator factory In oil and gas fired boiler, when the steam exhaust volume at the vent pipe of the expander is relatively large, there will be water hammer at the bottom of the equipment. In this way, the vibration of the pipeline will accelerate, and when the swing amplitude of the pressure gauge pointer in each part of the equipment is large, the temperature rise will be stopped and the constant temperature state will be maintained.

The fluctuation of waste heat boiler flue gas in flow, temperature, composition, dust content and other aspects is one of its characteristics. The nature of the fluctuation can be regular, periodic, or irregular, aperiodic; The characteristics of fluctuation can be gradual. Guangdong Steam generator It can also be impulsive; It can be a single parameter or a composite fluctuation of multiple parameters. The selection of waste heat boiler shall first analyze the whole cycle of the main process flow, and determine the flue gas characteristics of each time section in the cycle. small-scale Steam generator factory Therefore, corresponding measures shall be implemented one by one in the design of waste heat boiler. The prominent feature is often the main basis for the selection of waste heat boiler.

When the boiler is shut down, the temperature of the heat transfer oil can be reduced to below 70 ℃ before the shutdown of the hot oil pump. In case of sudden power failure, extinguish the fire immediately, and then implement the operating procedures. Otherwise, the furnace tube will be burned out and the loss will be large. According to the type of heat transfer oil boiler, heat transfer oil shall be reasonably selected to prevent overheating. Guangdong Steam generator When purchasing unqualified heat transfer oil, do not save money or mix heat transfer oil indiscriminately. Otherwise, the consequences will be very serious. Prevent the oxidation of heat transfer oil. The strict heat transfer oil is more than 50 degrees in contact with the air, which will make the heat transfer oil crack. Its speed is amazing, and the consequences are relatively serious. After normal operation, the test crew needs to close the exhaust valve on the auxiliary exhaust pipe. After 6 months of use, the heat transfer oil must be sampled and tested according to the instructions. If problems are found, the heat transfer oil must be replaced immediately. small-scale Steam generator factory However, it should be noted that different types of heat transfer oil should not be mixed. The circulation speed of the heat transfer oil should not be less than 1.5m/s. Due to the excessive temperature difference between some entrances and exits, the original design requirements were destroyed, the heat transfer oil could not maintain the original circulation state, the boundary layer became thicker, and the thermal resistance became larger, making the furnace wall exceed the oil film temperature, leading to carbon deposition, cracking, polymerization, coking, and even burning through the furnace tube.

The steam used in the steam generator of the hotel laundry is usually 0.4~0.6MPa saturated steam. The working temperature of steam is not very high. Guangdong Steam generator The steam boiler of the hotel requires high steam efficiency due to operating costs, so it can save operating costs. The area of the hotel is relatively limited, so the steam boiler with small floor area must be selected. In order to control the investment cost and heat loss of the steam pipe, the steam boiler is usually placed on the side of the laundry room. small-scale Steam generator factory The steam equipment in the hotel laundry room can only be turned on when washing, not when washing. Therefore, the steam generator is required to start steam production quickly. Laundry equipment is sometimes opened a lot and sometimes less, so the steam boiler is required to adjust the steam volume within the specified range.