Open AccessCOMPARATIVE ANALYSIS OF METHODS ESTIMATING POWER EFFICIENCY OF SHIP COMBINED THERMOTRANSFORMERS
Author(s) -
Mikhail Mikhailovich Drozdov,
Anna Olegovna Drozdova,
Vladimir Grigorievich Bukin,
Andrey Yurievich Kuzmin
Publication year - 2019
Publication title -
vestnik astrahanskogo gosudarstvennogo tehničeskogo universiteta. seriâ: morskaâ tehnika i tehnologiâ
Language(s) - English
Resource type - Journals
eISSN - 2225-0352
pISSN - 2073-1574
DOI - 10.24143/2073-1574-2019-2-64-70
Subject(s) - refrigeration , coefficient of performance , refrigerant , carnot cycle , heat exchanger , thermal expansion valve , boiling point , thermodynamics , heat pump and refrigeration cycle , mechanical engineering , process engineering , computer science , engineering , physics
The article discusses the issues related to the comparative analysis of various methods for evaluating the efficiency of ship combined thermotransformers, based on a comparison of similar trends and quantitative values of calculation results of heat transformers producing cold as a useful effect. There has been conducted analysis of literature on evaluating power plants operation, including combined thermotransformers. Agents R134 а, R22, R744, R717 are used as refrigerants on ships. The refrigerant R744 is not approved, because the assumed condensation temperature lies in a subcritical area, which makes cycles of a refrigerating machine differ from the other refrigerating machines under study. There has been given a design model of a one-step refrigerating machine without a regenerative heat exchanger. Quantitative comparison is made on the basis of obtaining the refrigeration coefficient of a thermodynamic cycle of the ship chilling machine operation in various ways. The results are compared with the parameters of the ideal Carnot’s principle and the refrigeration coefficient value neglecting losses from converting electrical energy into thermal energy. On the basis of the obtained data there have been drawn the conclusions about similarity of changing parameters of the dependence of the refrigeration coefficient on the boiling point obtained by calculations using various methods. It has been stated that the value of cooling coefficient is a direct function of boiling temperature; the maximum coefficient is found for ammonia (R717). The analysis may be useful in studying the ship power efficiency, which means producing maximum effect per a unit of expended cost.