engleski

Numerical Simulation of Transients in Shell and Tube Refrigerant Evaporator

A fully distributed dynamic numerical model of a shell and tube type refrigerant evaporator, suitable for control and design purposes, is presented. A void fraction model is used to account for the slip effect. The solution is achieved by the finite volume method. Original software is developed for the model implementation on computer. The thermal expansion valve model is added to the evaporator model in order to simulate the evaporator’s control loop. The spatial variations of pressure, temperature, enthalpy, mass flow rate, density, vapor and liquid velocities, void fraction and heat transfer coefficients are predicted through the time for the evaporator. Results of numerical simulations are presented in a graphical form. Measurements are performed on a 140 kW single stage compression heat pump with R22 as the working fluid. Simulation results and measurements are favorably compared for transient operation of an evaporator.

nije evidentirano

nije evidentirano