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. Henan Horizontal fuel gas 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 Horizontal fuel gas steam generator manufactor 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.
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. Henan Horizontal fuel gas 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 Horizontal fuel gas steam generator manufactor 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 starting of gas-fired boiler shall be carried out according to the operating procedures. The following is the accurate starting process of the analyzed gas-fired boiler: turn on the main power supply, start the gas-fired incinerator, and close the vent valve on the drum when it emits steam. Henan Horizontal fuel gas steam generator Check the manhole, handhole flange and valve of the gas boiler. If any leakage is found, fasten them. If leakage occurs after fastening, shut down the boiler for maintenance. When the gas pressure of the gas boiler rises by 0.05~0.1MPA, make up water, blow down, check the experimental water supply system and blow down equipment, and flush the water level gauge together. When the gas boiler pressure rises to 0.1~0.15MPA, flush the pressure gauge trap; When the gas pressure of the gas-fired boiler rises to 0.3MPA, turn the "load high fire/low fire" knob to "high fire" to strengthen incineration. When the pressure of the boiler rises to 2/3 of the operating pressure, start pipe warming and air supply, slowly open the main steam valve to prevent water hammer. small-scale Horizontal fuel gas steam generator manufactor When the drain valve emits steam, close it. After all the drain valves are closed, slowly open the main gas valve to fully open, and then reverse it for half a circle. Turn the "Control of gas incinerator" knob to the automatic gear.
High heat exchange efficiency. The fusion rate at the contact is more than 95%, the contact thermal resistance is small, and the thermal conductivity is good. Low flow resistance. Henan Horizontal fuel gas steam generator Since H-shaped finned tubes are similar to square structures, after being assembled into heat exchangers, the tubes are divided into many small channels by fins, which has a certain uniform effect on the air flow. The air flow is similar to longitudinal downstream flow, and the air flow resistance is relatively small. However, spiral finned tubes have strong air flow disturbance, high turbulence, and large air flow resistance due to the directivity of the fins. Less ash. The flue gas contains fly ash, which is easy to deposit on the windward side and leeward side of the pipe bundle. The H-shaped fin tube bundle has the characteristics of uniform flow and downstream flow, so it is not easy to cause serious local ash deposition, and the fly ash can be taken away with the air flow in time. Therefore, compared with spiral finned tube heat exchanger, H-type finned tube heat exchanger has less ash deposition. small-scale Horizontal fuel gas steam generator manufactor Small size and low weight. H-shaped finned tube has high area expansion rate, less ash deposition, and high heat transfer efficiency. When the heat transfer capacity is equal, the space occupied by the heat exchanger can be small. For reconstruction projects, the heat exchange area can be arranged as much as possible in the limited space to reduce the exhaust gas temperature, improve the waste heat recovery efficiency, or increase the maintenance space to facilitate maintenance.
Stainless steel for pressure vessels and its welding characteristics. The so-called stainless steel refers to the addition of a certain amount of chromium in the steel to keep the steel in a passive state and free from rust. Henan Horizontal fuel gas steam generator For this purpose, the chromium content must be more than 12%. In order to improve the passivity of steel, it is often necessary to add nickel, molybdenum and other elements that can passivate steel into stainless steel. Stainless steel is generally referred to as stainless steel and acid resistant steel. Stainless steel companies do not have certain acid resistance, and acid resistant steel generally has a good stainless property. small-scale Horizontal fuel gas steam generator manufactor According to its steel structure, stainless steel can be divided into four categories, namely, austenitic stainless steel, ferritic stainless steel, martensitic stainless steel, and austenitic ferritic duplex stainless steel.
