The matrix method for calculating complex heat and mass transfer systems with multicomponent coolants

Abstract

Earlier, we obtained a solution to the heat transfer problem in multi-threaded multi-stage heat-exchanging units with one-component heat carriers. However, in the energy, food, and petrochemical industries, often heat and mass transfer processes involve coolants consisting of components whose heat and physical properties differ significantly. For carrying out heat engineering calculations with such coolants, averaging of the indicated properties of the components is usually performed. However, in a number of industrial technologies based on distinguishing thermo-physical properties, in particular, differences in the boiling temperature of the components, processes for their separation by distillation are used. In this case, when calculating heat and mass transfer processes to obtain pure components with acceptable impurities, it is necessary to take into account the difference in their thermo-physical properties precisely. The development of calculating methods for the systems of multi-threaded multi-stage heat transfer processes with multi-component coolants to analyze the efficiency of their separation is a topical issue facing the energy sector and related industries. To study and simulate heat and mass transfer systems, the equations of mass and energy balances and linear algebra methods of are used. Within the framework of the matrix approach, for the case of using a mixture of components with different boiling points as heat transfer agents, a heat and mass transfer process model has been obtained. The model allows evaluating the degree of separation of components and the quality of the finished product by the content of impurities in it for various methods of organizing the process. The solutions of the model equations have been obtained and analyzed. The results can be used to increase the efficiency of resource and energy-saving technologies in solving problems of the optimal distribution of temperatures at the system stages due to recirculation of the selected components and to obtain pure components with an acceptable content of impurities in the energy, chemical and food industries.