Optimization method for determining flue gas excess heat organic Rankine cycle system parameter

Abstract

The invention provides an optimization method for determining a flue gas excess heat organic Rankine cycle system parameter. The optimization method comprises the steps of taking into account of a cooling water cycle to establish a thermodynamic model; through a first law of thermodynamics and a second law of thermodynamics, obtaining system net output power, water pump waste power, heat efficiency, (the formula is shown in the description) efficiency and irreversible loss, and according to the influence of an evaporation temperature and an expansion ratio on system thermodynamic performance, determining an optimal evaporation temperature; under the optimal evaporation temperature, calculating heat exchange areas of an evaporator and a condenser, wherein it is defined that an economical objective function is the ratio of the system net output power to the area of the evaporator to the area of the condenser, and the comprehensively evaluation function is the weighted sum the economical objective function (the formula is shown in the description) and the efficiency; with the comprehensive evaluation function being an optimization target, determining an optimal condensation temperature; according to the optimal evaporation temperature and the optimal condensation temperature, determining system parameters of work medium mass, cooling water mass, evaporation pressure, condensation pressure, an expansion ratio, the net output power, the heat efficiency and the irreversible loss. According to the optimization method for determining the flue gas excess heat organic Rankine cycle system parameter, the optimal evaporation temperature and the condensation temperature can be determined, and thus the optimal system parameter is determined.

Description

technical field [0001] The invention relates to a method for optimizing parameters of an organic Rankine cycle system. In particular, it relates to an optimization method for determining the parameters of an organic Rankine cycle system for waste heat of flue gas. Background technique [0002] If the medium and low temperature flue gas and exhaust heat of internal combustion engines produced in industrial processes cannot be effectively recycled, it will not only waste energy, but also make thermal pollution a serious environmental problem. Organic Rankine cycle is a new type of environmentally friendly power generation technology to solve the problem of medium and low temperature waste heat recovery and power generation. It can use organic working fluid to recover the waste heat of medium and low temperature flue gas and then generate electricity. It has become an effective technical way to recover low-grade heat energy. [0003] At present, there are many researches on th...

AI Technical Summary

Problems solved by technology

The condensing temperature of the organic working fluid is a key factor affecting the system performance and the power consumption of the cooling water circulation pump, because the efficiency of the organic Rankine cycle system is relatively low, the heat released during the condensation process is large, the cooling water demand is large, and the power consumption of the cooling water pump has a great impact on the net output power of the system. The impact of the cooling water pump is relatively large, and ignoring the power consumption of the cooling water pump will cause certain errors in the system optimization results.

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