Abstract
Keywords - Refrigeration control, refrigeration system optimization, system efficiency, refrigeration model, CO2 reduction.
Abstract - The current need to diminish the emission pollutants, and especially the CO2 for its contribution to the greenhouse effect, forces the manufacturers of vehicles to minimize the energy consumption of all the systems that integrate them. One of the necessary systems to support the level of comfort nowadays demanded by the users is that of air conditioning.
The present work approaches the development, across models of calculation, of a strategy of integral control of the system of refrigeration of a vehicle directed to minimizing the consumption of energy (and therefore the emission of CO2 associated) supporting the level of comfort of the cockpit demanded by the users.
Most of the control of the air conditioned systems nowadays in use operate by means of the interruption of the operation of the compressor as soon as a temperature threshold has been reached, and in the later take-off of the equipment when the temperature decreases a fixed amount (∆Τ ~ 1.5 ºC) below that temperature threshold.
In this study is analyzed the potential of energy saving in the operation of the system, opposite to the method based on the start - stop, when the system acts simultaneously on:
Maximum pressure to the exit of the compressor
Gas flow of cooling in the condenser
Gas flow of cooling in the evaporator
Speed of the compressor.
The control of the maximum pressure allows to decrease the indicated work consumed in the compressor without modifying the cooling capacity of the system. On the other hand, the control of the speed of the compressor together with that of the gas flow of cooling, it allows to the system to adapt to variations of the demand of cold. The results of the model shown that with an optimal management in the vehicle analyzed is feasible to save at least a 13 per cent of the energy needed to feed an air conditioned system controlled by an on off strategy.