Condensing gas-fired steam boilers use the principle of releasing a large amount of latent heat of vaporization in the process of condensing water vapor into liquid water. The exhaust gas temperature is reduced to 50~70℃ by adding a flue gas waste heat recovery device. The sensible heat and condensation latent heat of water vapor in the flue gas are fully recovered. WNS model gas boiler has high thermal efficiency and remarkable energy saving effect.
The volume share of water vapor in the flue gas of condensing steam boilers fueled by natural gas is generally 18% to 19%. The water vapor content in the flue gas of oil-fired boilers is 12%~13%, which is much higher than the water vapor content of less than 6% in the flue gas produced by coal-fired boilers. At present, the thermal efficiency of boilers is calculated based on the low calorific value. Although the thermal efficiency is higher in name, the actual energy utilization rate needs to be improved due to the difference of about 10% between the high and low calorific value of natural gas. In order to make full use of energy, reduce the exhaust gas temperature and recover the physical heat energy of the flue gas. When the wall temperature of the heat exchanger is lower than the dew point temperature of the flue gas, the water vapor in the flue gas will be condensed. By releasing latent heat, the 10% difference in heat generation between high and low positions can be effectively utilized.
The exhaust gas temperature of the WNS type gas-fired steam boiler is one of the basic design parameters of the boiler. This parameter must be selected first when designing the boiler. The exhaust gas temperature of this type of boiler product directly affects the economy of the boiler unit and the safety of the rear heating surface. Selecting a lower exhaust gas temperature can reduce the heat loss of the boiler exhaust gas, which is beneficial to improve the thermal efficiency of the boiler, save energy and reduce the operating cost of the boiler. The WNS model gas boiler uses the wet back structure combustion chamber completely flooded into the water, and the cooling condition is good. The back tube sheet of the boiler is not washed by high temperature flue gas and has a long service life.
This series of gas boilers adopts a wet-back three-return structure as a whole. The smoke pipes are symmetrically arranged and evenly distributed, which can improve the stress distribution of the tube sheet. The boiler has a large steam space to make the steam out of the water surface at a low speed, and has a built-in steam-water separation device to ensure stable output of high-quality steam. This type of boiler flue has no bypass flue, and it can be adjusted whether to use the condenser according to the size of the boiler load.
The condensing gas boiler is designed with a modular combination integrated arrangement. The main engine of the boiler is composed of four independent units: the boiler body, the connecting flue, the economizer and the condenser. After the gas steam boiler is assembled, the economizer and the condenser are placed on the upper left of the boiler body, and are connected to the boiler body through the connecting flue. This furnace structure has the characteristics of compact layout, beautiful appearance and convenient maintenance.
The energy-saving effect of the WNS model gas boiler is more significant, and the thermal efficiency calculated by the low calorific value exceeds 100%. At the same time, after the flue gas is condensed, some harmful substances in the flue gas are dissolved in the condensed water, which can purify the flue gas. Therefore, this product has the dual effect of energy saving and emission reduction. Product specifications and models include steam 2t, 4t, 6t, 8t, 10t and so on.