Han Yuan

Investigation on an ammonia supply system for flue gas denitrification of low-speed marine diesel

Low-speed marine diesel flue gas denitrification is in great demand in the ship transport industry. This research proposes an ammonia supply system which can be used for flue gas denitrification of low-speed marine diesel. In this proposed ammonia supply system, ammonium bicarbonate is selected as the ammonia carrier to produce ammonia and carbon dioxide by thermal decomposition. The diesel engine exhaust heat is used as the heating source for ammonium bicarbonate decomposition and ammonia gas desorption. As the ammonium bicarbonate decomposition is critical to the proper operation of this system, effects have been observed to reveal the performance of the thermal decomposition chamber in this paper. A visualization experiment for determination of the single-tube heat transfer coefficient and simulation of flow and heat transfer in two structures is conducted; the decomposition of ammonium bicarbonate is simulated by ASPEN PLUS. The results show that the single-tube heat transfer coefficient is 1052u2009Wu2009m2u2009°C−1; the thermal decomposition chamber fork-type structure gets a higher heat transfer compared with the row-type. With regard to the simulation of ammonium bicarbonate thermal decomposition, the ammonia production is significantly affected by the reaction temperature and the mass flow rate of the ammonium bicarbonate input.

Combustion characteristic of coal–ammonia composite

ABSTRACT In this article, the combustion characteristic of coal–ammonia composite is investigated. Raw coal and preheating modified coal are treated to absorb the ammonia. Four kinds of samples are made to conduct the thermal balance experiments. The results show that the content of ammonia in the coal–ammonia composite greatly affects its combustion characteristics. The coal–ammonia composite has a lower carbon emission than the raw coal when the same amount of heat is released. Besides, the performances of raw coal can also be improved by preheating treatment, but the coal–ammonia composite has better combustion performances with the same amount of calorific value.

Theoretical Investigation of a Power Cycle Using Ammonia-Water as Working Fluid

A novel ammonia-water power cycle is proposed, which uses low-temperature heat sources such as oceanic-thermal, biomass as well as industrial waste heats. An ejector is introduced between the turbine and the absorber. The main emphasis is placed on the energy and exergy analysis to guide the thermodynamic improvement for the cycle; parametric analysis is conducted to investigate the effects of thermodynamic parameters on the cycle performances. The result shows that the thermal efficiency can reach to 5.31% and the exergitic efficiency varies between 13.3% and 24.4% under the given condition. In addition, the generator pressure, the deflation ratio variation and the turbine outlet depressurization made by ejector have significant effects on the performance of the power cycle.