Numerical simulation of parameters of the thermal scheme of the waste heat recovery system

Abstract

Hybrid power plants were first proposed in the development of geothermal deposits in Kamchatka in 1964-66. The unit consists of two circuits, which use a steam turbine with a temperature of up to 200 ° C, with a degree of dryness of water vapor is 5% and a turbine on R12 refrigerant with a capacity of 5 MW. Electric power is 12 MW. Hybrid power plants are also used in metallurgy, cement and glass industries where the heat of exhaust gases with temperatures up to 350 ° C is used. A feature of the design calculations is the uncertainty of changes during the future life of some of the initial data, in particular, specific cost indicators. The available experience and the analysis of approaches to development of flowing parts of turbines have shown that depending on degree of expansion and expenses of working bodies the corresponding type of flowing part is chosen. The calculated studies of the three-circuit thermal circuit (at a discharge temperature of 350 ° C) showed that increasing the parameters of the working fluids is not always rational. Increasing the heat drop on the turbine leads to an increase in the number of turbine stages, but the cost of the working fluid is not enough to abandon the partial drive. The one-dimensional calculation does not show a complete picture of the flow in the flowing part of the turbine, which will have large losses from secondary flows and flows of the working fluid due to the low height of the blades and a high degree of partiality. The results also allow us to conclude that the most appropriate is the implementation of a double-circuit thermal scheme and increase the consumption of working fluids. Increasing the number of circuit elements and possible combinations of their connections, expanding the range of changes in the initial data, factors of systemicity and uncertainty significantly complicate the choice of the final version of the thermal circuit.