Throughout my career, as a specialist in industrial ammonia refrigeration, I have encountered numerous refrigeration installations with high and unnecessary electrical energy consumption. In this article, I will explain some of the most important concepts to take into account when carrying out an industrial refrigeration project. This information could be very useful for those who are developing project engineering, analyzing a technical offer for the purchase/sale of a facility or carrying out an energy audit. Table of Contents What is the COP – Coefficient of Performance – in Compressors for Industrial Refrigeration? The Performance Coefficient or performance is the number that relates the benefit obtained (compressor cooling capacity) and the amount invested for said benefit (electrical power demanded). It is a fundamental tool for the people who develop the industrial refrigeration project and as a sales argument for the potential supplier. The Coefficient of Performance or COP performance of a compressor is the relationship between the heat extracted per unit of time and the power required for it.
The higher the COP value, the lower the energy consumption of electrical energy, it is a number dimensionless. COP = Q / N, in the same units, therefore it is a dimensionless number. Q : Compressor capacity N: Electrical power demanded The COP value of a compressor at full load depends, for the same condensing pressure, on the evaporation pressure. The higher the evaporation pressure, the higher the Coefficient of Performance or performance Japan Telegram Number Data value will be. This means that You must always choose the highest evaporation pressure and therefore the highest evaporation temperature compatible with the cooling process. This criterion implies a greater investment in evaporator exchange surface , which is paid only once, but the investment begins to be recovered from the day the installation enters service, once the investment is recovered, the savings continue during the operation of the refrigeration plant.
Online Courses on Industrial Refrigeration by NH3 View Courses How does the capacity of a screw compressor vary and what is its influence on the COP – Coefficient of Performance? Screw refrigeration compressors regulate their capacity in such a way as to adjust their cooling power to the instantaneous cooling demand to keep the evaporation pressure constant and at the working value. At the initial moment of the refrigeration process, the power or refrigeration capacity is maximum and from that moment on it can be maintained when it is a continuous process such as a hamburger freezing tunnel for example, or begin to decrease as happens with a cold room once who closed his door. The capacity variation of a screw compressor can occur in 3 variants: By means of automatic sliding valve: the compressor has a sliding valve activated by a hydraulic system that allows the capacity to be varied continuously from 10% (minimum capacity) to 100% (maximum capacity) in order to maintain constant evaporation pressure, it can be assimilate as the “decrease in displacement” of an reciprocating compressor.