Investigation of the dynamic heat transfer coefficient of R-134a in a horizontal pipe

摘要

This article presents a test rig to measure the dynamic heat transfer coefficient of the refrigerant R-134a in a small-diameter horizontal pipe. The experiment layout is basically a cooling cycle. The basic components are a receiver tank filled with R-134a, a pump, an evaporator pipe, and a condenser. The evaporator pipe made out of copper is the main element. Thermocouples, pressure sensors, and a mass flow sensor provide the information necessary to determine the heat transfer coefficient of the horizontal pipe. In addition to the experimental investigations, a numerical model is created. The results are compared with the test rig results to validate the numerical model.