An adsorption chiller that is integrated into the overall design allows the conversion of waste heat from the transcritical CO2 system into useful energy for cooling. Such use of adsorption cooling leads to improvement in the overall electrical energy consumption by approximately 5%.
Using the waste heat efficiently - not only in winter
Transcritical CO2 refrigeration systems release considerable amounts of waste heat depending on the operating conditions. In winter this can be used for heating the building, however, in summer this energy usually gets lost. With the pioneering design of Frigo-Consulting AG, the waste heat is now used to drive an adsorption chiller that generates additional cooling and thus supports the R744 refrigeration system. The two systems are expected to complement one another perfectly, as high ambient temperatures lead to higher unused waste heat in the refrigeration system and this is when additional cooling from the adsorption chiller is especially effective.
Reducing cost, energy consumption and emissions
The adsorption chiller powered by the waste heat can reach a cooling capacity of up to 10 kW at high ambient temperatures. This energy is used for additional cooling of the refrigerant after it has passed the gas cooler. The cooling capacity of the conventional CO2 refrigeration system can this way be increased by that same amount of cooling capacity from the adsorption system. Furthermore, the additional cooling after the gas cooler leads to a lower head pressure of the CO2 system, reducing the compression work. Both effects combined will reduce the total energy consumption by about 5%.
By using standard components for the adsorption chiller and its integration into the refrigeration system, the costs can be reduced to a minimum, while ensuring high operating reliability.
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