Numerical Study of the Characteristics of the Air Condenser Section

Abstract

Abstract. Relevance of the work is due to the need to create a mathematical model of thermal processes in the air condenser section (AC). The purpose of the work is to the development and testing a mathematical model applied to the section AC condensation of low-boiling substances used as working materials in the organic Rankine cycle. A mathematical model was developed, and allows complex investigations that involve a change in the type of working material and geometric and operational parameters section AC. For the calculation of thermal parameters using a database of properties of substances «REFPROP». On the basis of the mathematical model in Excel spreadsheet package developed a program for calculating the parameters and performance measures of AC. The numerical model studies have shown that the characteristics and performance indicators AC highly dependent on the type of substance. When changing external air temperature from -40 to 40 °С heat flux in the AC falls to 175 ÷ 185 W/m 2 . The model allows to determine the number of sections and investments in the condenser of the known heat flow. Heat flow must be selected based on outdoor temperature taking into account the climatic conditions of the AC.

Improvement air condensers evaluation model

“…One of the most serious problems of AC operation in winter during the condensation of water vapor is the condensate freezing in the tubes, which can lead to the destruction of tubes and the need to repair the condenser and stop the turbine. The solution to this problem is to use the AC in a CCGT with three cycles, where the low-boiling substances (LBS) [3] operates in the lower cycle, and its condensation can reliably pass at temperatures below -40 °C [4].…”