scholarly journals Endoreversible Modeling and Optimization of a Multistage Heat Engine System with a Generalized Heat Transfer Law via Hamilton-Jacobi-Bellman Equations and Dynamic Programming

2011 ◽  
Vol 119 (6) ◽  
pp. 747-760 ◽  
Author(s):  
S. Xia ◽  
L. Chen ◽  
F. Sun
2017 ◽  
Author(s):  
Shaojun Xia ◽  
Lingen Chen

A multistage endoreversible Carnot heat pump (CHP) system with a finite heat sink and generalized convective heat transfer law (HTL) [q ∝ (AT)m] is investigated. For the given initial sink temperature, the minimum power consumption (MPC) is chosen to be optimization objective, the sink temperature is the control variable, and the corresponding continuous Hamilton-Jacobi-Bellman (HJB) equation is established. The detailed expressions of the MPC and the corresponding heat sink temperature for Newtonian HTL (m = 1) are further obtained based on the universal results. While for the cases with other HTLs (m ≠ 1), there exists no analytical solution, so numerical algorithm of dynamic programming (DP) is used, and the difference between the MPC optimization of the multistage endoreversible CHP system and the maximum power output (MPO) of the multistage endoreversible Carnot heat engine (CHE) system is also indicated. The obtained results in this paper could help an engineer in better evaluation of energy limits in practical power-consumption processes.


2012 ◽  
Vol 34 (5) ◽  
pp. A2625-A2649 ◽  
Author(s):  
Simone Cacace ◽  
Emiliano Cristiani ◽  
Maurizio Falcone ◽  
Athena Picarelli

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yingjun Zhu ◽  
Guangyan Jia

Bellman optimality principle for the stochastic dynamic system on time scales is derived, which includes the continuous time and discrete time as special cases. At the same time, the Hamilton–Jacobi–Bellman (HJB) equation on time scales is obtained. Finally, an example is employed to illustrate our main results.


2010 ◽  
Vol 14 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Jun Li ◽  
Lingen Chen ◽  
Fengrui Sun

Optimal temperature profile for maximum work output of multistage continuous Carnot heat engine system with two reservoirs of finite thermal capacity is determined. The heat transfer between heat source and the working fluid obeys radiation law and the heat transfer between heat sink and the working fluid obeys linear law. The solution is obtained by using optimal control theory and pseudo-Newtonian heat transfer model. It is shown that the temperature of driven fluid monotonically decreases with respect to flow velocity and process duration. The maximum work is obtained. The obtained results are compared with those obtained with infinite low temperature heat sink.


Author(s):  
Lan Mei Wu ◽  
Guo Xing Lin

An irreversible solar-driven Braysson heat engine system is put forward, in which finite rate heat transfer with the radiation-convection mode from the solar collector to the heat engine and the convection mode from the heat engine to the heat sink, the radiation-convection heat loss from the solar collector to the ambience, the internal irreversibility due to nonisentropic processes in the expander and compressor devices are taken into account. On the basis of thermodynamic analysis method, the analytic expression between the overall efficiency of the solar-driven Braysson heat engine system and the operating temperature of the solar collector is derived and the influences of different heat transfer mechanism, the internal irreversibility parameter, the isobaric temperature ratio, the ratio of heat-transfer coefficients on the optimal performance of the solar-driven Braysson heat engine system are evaluated and depicted quantificationally. The results obtained in the present paper are helpful to deeply reveal the effect of heat transfer mechanism and multi-irreversibilities on the performance of solar driven heat engines.


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