Research And Application On Models Of Thermal Exergy Price In Synthesis Of Distillation Process

The development and design optimization of separation process system are very important to the process industry. Energy consumption is the leading character of separating process whose essence of design optimization is the optimization of the balance between energy and economic. Selecting an appropriate objective is the foundation of this kind of optimization. At present, it is subjective that the unit prices of raw material and products in economic or exergoeconomic objective are decided by users. Therefore, building an appropriate objective has great significance to the research of separation process synthesis.Exergoeconomics is a very important realm of engineering thermophysics and base on strict thermodynamics theories. Furthermore, it is a main method to deal with balance between energy and economics whose main research object is thermal system. In this paper, exergoeconomic analysis is applied to multi-components distillation process synthesis which is conventional realm of chemical engineering. Model building of exergy price is the first step of the research. It is mainly based on the followings:1. In this article, basing on exergy balance and exergy cost balance equation, considering the price of fuel and power we put forward four basic suppositions about the model of thermal exergy price :â‘ exergy cost balance;â‘¡the cost of exergy destruction is zero;â‘¢the price of primitive energy and power are constants;â‘£the price of process material flows is zero. The economic factor and changes of quantities and qualities are considered in these suppositions. Additionally, using the above four suppositions, we put forward the scheme of thermal exergy price model about steam, hot water, heat-medium and process material flow.The models indicate: The price of exergy is not a constant and is strongly related to conversion process. The price of steam from cogeneration system has a direct proportion to temperature of the steam, which accorded with ordinary price rule. While the price of steam from boiler system has an inverse proportion which not accorded with ordinary price rule, but it is rational. The rationality is that the cheapest...