IMPROVING THE LEARNING PROCESS BY USING EXPERIMENTAL TRAINER FOR CHARACTERIZATION OF REFRIGERATION CYCLE

Learning from applied experiments is a very effective learning method. An experiment usually tests a hypothesis, which is an expectation about how a particular process or phenomenon works. However, the experiment will help engineering students to understand the complex phenomena and to extract data from a refrigeration cycle. Regarding this we develop an educational experimental refrigeration trainer. The goal of this trainer is to enable students to understand some theoretical concepts.

This system is a typical refrigeration circuit made of the following parts:
a. a hermetic compressor,
b. a condenser and an evaporator, as fine tube heat exchangers with partially transparent tubes to view evaporation and condensation inside the tubes,
c. an expansion element with three capillary tubes of different lengths and a thermostatic expansion valve.

The trainer contains a refrigerant receiver, through which refrigerant can either be added or removed from the circuit, creating effects of overfilling or underfilling, which can be observed by students at a PC using a specialized software. All the measured values are sent directly to the PC and recorded in dynamic log p-h diagrams.

The paper presents the results of the experiment work conducted by students and they will be able to determine the refrigeration capacity, the coefficient of performance and the efficiency of the compressor.