Rao W.-J.,Key Laboratory of Low Grade Energy Utilization Technologies and Systems of Ministry of Education |
Zhao L.-J.,Key Laboratory of Low Grade Energy Utilization Technologies and Systems of Ministry of Education |
Liu C.,Key Laboratory of Low Grade Energy Utilization Technologies and Systems of Ministry of Education |
Xu J.-L.,North China Electrical Power University |
Zhang M.-G.,Key Laboratory of Low Grade Energy Utilization Technologies and Systems of Ministry of Education
Kung Cheng Je Wu Li Hsueh Pao/Journal of Engineering Thermophysics | Year: 2014
In this paper, the cold exergy of LNG and industrial waste heat are connected to be recovered using organic Rankine cycle, in which ethane is selected as working fluid. Thermodynamic analysis for the cycle is done in detail. The results show that both cycle thermal efficiency and work output increase as the increase of evaporation pressure. When the outlet temperature of evaporator is lower than 240°C and the value of evaporation pressure is much high, negative pinch point temperature which is not allowed will appear in the condenser. It means that heat exchange amount in the condenser is not enough for LNG to achieve the final supplied temperature. Therefore, when utilizing industrial waste heat lower than 260°C and cold exergy of LNG, in order to avoid insufficient heat transfer at high pressure for the condenser, a heat exchanger should be added to the original cycle.
Chen Y.,Key Laboratory of Low grade Energy Utilization Technologies and Systems of Ministry of Education |
Chen Y.,Chongqing University |
Hangxing H.,Key Laboratory of Low grade Energy Utilization Technologies and Systems of Ministry of Education |
Hangxing H.,Chongqing University
ICOPE 2015 - International Conference on Power Engineering | Year: 2015
An equation-free multiscale method is proposed for simulating two-phase gas-liquid separation processes. The lattice Boltzmann (LB) model is used as the meso-scopic simulator for the equation-free method. Only a small amount of evolutionary steps are needed during the computation, the results obtained from the meso-scopic simulator are reasonably extrapolated by second-order telescopic projection to predict the results of follow-up evolutionary steps quickly and precisely, which achieve the multiscale research of two-phase gas-liquid separation processes. The details of phase separation are presented by numerical simulation results in terms of coexistence curves and spurious currents, and these results are found in excellent agreement with experimental and theoretical data with less time consuming. Characteristics of phase separation can be quickly and accurately reflected by the proposed multiscale simulation method. The results indicate that the proposed equation-free multiscale method is a potential candidate for simulating complex heat-flow problems. And this work will be helpful for our long-term aim of multiscale modeling of convective boiling. © 2015 The Japan Society of Mechanical Engineers.