(LN) WNs series fully automatic fuel (gas) steam boilers are made of corrugated furnace, threaded pipe, three return and full wet back structure. The fuel is in the positive pressure combustion of the fuel in the furnace chamber, and the high temperature flue gas enters the first thread flue pipe bundle along the back of the furnace chamber through the combustion chamber, and enters the second bundle tube through the pressurized smoke box turning 180 degrees, and is discharged into the atmosphere after convection heat transfer. A three return steam boiler with large capacity is designed by using the design idea of the three symmetrical return structure. The biggest feature of the boiler is all the pressure parts and the drum.
The central symmetric boiler adopts a fully wet back structure with a large inner cylinder and a fire box structure, which is conducive to providing enough radiant heating surfaces. The convection heating surface consists of second return and three return tubes. The front tube plate of the reburning chamber is connected with the furnace chamber, and the back tube plate of the reburning chamber is connected with the rear tube plate of the cylinder by the back pull braces. The second return and third return smoke chambers make up the front smoke box, and the smoke temperature is below 500 C. Therefore, the structure of the front smoke box adopts a fireproof thermal insulation material with light structure. The design of the boiler mainly considers the principle of boiler overhaul and stability. The water mixing device installed at the inlet of the boiler feed water first washes the tube bundles of the smoke pipes, and the water temperature of the water supply contact furnace is raised in the contact furnace. The phenomenon of subcooled boiling is avoided. The steam boiler reaches the maximum vaporization space, and the advanced steam water separation device is used. The main steam quality is quite stable.
This series of boiler uses waveform furnace, which not only enhances the disturbance of flue gas, but also increases the radiation heat transfer area. It not only increases the rigidity of the furnace, but also effectively reduces the expansion stress of the furnace. It not only enhances the heat transfer effect, but also promotes the welding process of the combustion pipe and the fire box in the furnace. By pre dilatation, eliminating the gap between tube and tube sheet and welding, the corrosion and crystallization phenomena in high temperature zone can be effectively prevented.
Scale alarm function (matching) real-time monitoring the quality of heated surface water, once exceeding the standard, automatic alarm.
The exhaust gas temperature of a general condensing gas-fired steam boiler is higher than that of an ordinary boiler, where the water vapor is overheated and the gas state exists. If the exhaust gas temperature is lowered to a low enough level, the vapor in the flue gas will coagulate and the latent heat of vaporization of the condensate can be utilized. Most of the components of natural gas are methane (CHa), and the water in the combustion products is more than 18% of the total steam. After 1 cubic meters of natural gas burning, 1.55Kg vapor can be generated. In the available heat of the exhaust gas from the boiler, the latent heat of vaporization of steam occupies a large share, about 3700K/Nm3, accounting for more than 10% of the low calorific value of natural gas. The heat generated by the combustion of ordinary boilers is transmitted to the working fluids of 80-85%. Heat dissipation accounts for about 1%, and according to the different fuel, the maximum exhaust loss can reach up to 20-30% of high calorific value. For ordinary natural gas boilers, the heat loss taken by steam takes up 55%~75% of the total exhaust loss. The boiler efficiency can be increased by 2~5% if the exhaust temperature of the boiler is reduced to more than the dew point of the vapor, and if the exhaust gas temperature is reduced below the dew point of the boiler, The latent heat of vaporization is recovered and the thermal efficiency can be increased by more than 11%~15%. It is called condensing boiler that absorbs water vapor from condensing flue gas and fully absorbs the exhaust heat of boiler. Fully condensing waste heat recovery steam boiler is a highly efficient pressure condensing heat exchanger and atmospheric condensation heat exchanger to absorb latent heat released by the sensible heat and condensation of steam in the tail gas of the boiler, so as to improve the thermal efficiency of the boiler.