TY - JOUR
T1 - Evaluation of a flue gas driven open absorption system for heat and water recovery from fossil fuel boilers
AU - Wang, Zhenying
AU - Zhang, Xiaoyue
AU - Li, Zhen
N1 - Funding Information:
The research was sponsored by the National Basic Research Program of China “973” ( 2013CB228301 ) and the National Natural Science Foundation of China (Grant nos. 51321002 and 51376097 ).
Publisher Copyright:
© 2016 Elsevier Ltd
PY - 2016/11/15
Y1 - 2016/11/15
N2 - This paper presents an open absorption system for total heat recovery from fossil fuel boilers using the high temperature flue gas as the regeneration heat source. In this system, liquid desiccant serves as the recycling medium, which absorbs waste heat and moisture contained in the low temperature flue gas in the packed tower and then regenerates in the regenerator by the high temperature flue gas. Water vapor generated in the regenerator gets condensed after releasing heat to the heating water system and the condensing water also gets recycled. The return water collects heat from the solution water heat exchanger, the flue gas water heat exchanger and the condenser respectively and is then used for district heating. Driven by the vapor pressure difference between high humidity flue gas and the liquid desiccant, the heat recovery efficiency of the system is not limited by the dew point of the flue gas, enabling a warmer water to be heated up than the conventional condensing boiler. The performance of this system was analyzed theoretically and experimentally and the results showed that the system operated well for both district heat supply and domestic hot water supply. The system efficiency increased with the moisture content of flue gas and the total heat recovery was about 8.5%, 17.2%, 21.2%, and 9.2% higher than the conventional condensing system in the case of coal fired boiler, fuel oil boiler, natural gas boiler, and coke oven gas boiler, respectively.
AB - This paper presents an open absorption system for total heat recovery from fossil fuel boilers using the high temperature flue gas as the regeneration heat source. In this system, liquid desiccant serves as the recycling medium, which absorbs waste heat and moisture contained in the low temperature flue gas in the packed tower and then regenerates in the regenerator by the high temperature flue gas. Water vapor generated in the regenerator gets condensed after releasing heat to the heating water system and the condensing water also gets recycled. The return water collects heat from the solution water heat exchanger, the flue gas water heat exchanger and the condenser respectively and is then used for district heating. Driven by the vapor pressure difference between high humidity flue gas and the liquid desiccant, the heat recovery efficiency of the system is not limited by the dew point of the flue gas, enabling a warmer water to be heated up than the conventional condensing boiler. The performance of this system was analyzed theoretically and experimentally and the results showed that the system operated well for both district heat supply and domestic hot water supply. The system efficiency increased with the moisture content of flue gas and the total heat recovery was about 8.5%, 17.2%, 21.2%, and 9.2% higher than the conventional condensing system in the case of coal fired boiler, fuel oil boiler, natural gas boiler, and coke oven gas boiler, respectively.
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U2 - 10.1016/j.enconman.2016.09.050
DO - 10.1016/j.enconman.2016.09.050
M3 - Article
AN - SCOPUS:84988727897
SN - 0196-8904
VL - 128
SP - 57
EP - 65
JO - Energy Conversion and Management
JF - Energy Conversion and Management
ER -
