Applied Energy, Vol.237, 635-645, 2019
Dynamic operating conditions strategy for water hybrid cooling under variable heating demand
This work presents a study of a dynamic strategy for obtaining the lowest consumption of electrical energy in pumps and fans with varying operating conditions for the hybrid cooling of water, which is used as thermal fluid in a cooling unit for vegetable oil. The effects of the operating variables (air flow rate, water flow rate and heating power) on the cooling of water and oil and the electrical energy consumption were evaluated. The selection of the best water-cooling strategy was conditioned to the maximum inlet temperature of 90 degrees C, resulting in improvements in the energy efficiency that ranged between 35% and 94%, when compared to the use of fixed and nominal operating conditions. Thus, the evaluation of the operating variables effects dependency is strategic for the adequation of the operational conditions and obtainment of better energy efficiency for the process with variable demands.
Keywords:Heat exchanger;Variable thermal demand;Operating conditions correlations;Hybrid cooling;Reduction of electric energy consumption