Experimental study on flow and heat transfer performance of condensing gas-fired boiler

Abstract

In the process of energy utilization, a large amount of heat transfer needs to be realized through the heat exchange process. Therefore, the development of efficient enhanced heat exchange technology has important theoretical and application value for realizing the efficient utilization of energy and reducing pollutant emissions. Condensing heat exchanger is the core component of condensing water heater. Firstly, this paper analyses the development trend of condensing heat exchanger at home and abroad, and studies the heat exchange, pollutant emission and structural optimization design of condensing heat exchanger by using the gas water heater test-bed. Using the field synergy theory, the flow channel and fin structure of the heat exchanger are optimized. The series flow channel on the water side of the heat exchanger is optimized as the structure of first parallel and then series flow, so that the heat transfer capacity of the water side of the heat exchanger can be increased by 5.6% at the maximum, the reduction of NOx emission concentration is relatively less than 6.7%.