People cannot live a comfortable life without heating boilers in the winter, the normal and stable heat source is of great importance to human life. What is following is the increasingly serious problem of environmental pollution, implementing the policy of “coal to gas” is no time to delay, using gas-fired hot water boilers has been the general trend. Tianjin Jizhuangzi heat supply center is an enterprise specializing in city heat supply. In order to realize the “green heating”, the heat supply center decided to introduce a branch of gas-fired boilers to replace the old coal-fired boilers. ZOZEN successfully won the trust of Jizhuangzi heat supply center with its own strong comprehensive strength and rich experience in the heating industry. JIzhuangzi chose to cooperated with ZOZEN and ordered 3 sets of 58MW gas-fired hot water boilers (SZS58-1.6/130/70-Q) to provide heating source for citizens. This series of boilers adopts the design of ” D ” type membrane wall structure, the steam drum, the water drum and convection tube bundle form the convection heating surface to ensure the the boiler expands on both ends as a whole; at the same time, the combustion chamber is designed with the narrow distance tube membrane water cooling wall to reduce heat lost, in addition, the boiler is equipped with a big combustion chamber for the full combustion of fuel, effectively increasing the boiler thermal efficiency over 98% and reducing the NOx to 30mg, which are superior to the national level one energy efficiency standard.