Conversion of A medium heavy heating oil tank into A heat storage tank

Switching to natural gas and refinery gas as combustion fuels during refinery modernization, results in a considerable low usage of a medium heavy heating oil, and an open question of the tank function in which such an oil has been stored. There is an idea to make a conversion of such tanks into heat storages and their integration into the cogeneration plant within oil refinery. The analysis of the conversion of two such existing characteristic tanks was made in this paper. Validation of the model is done by comparing the measurement results on the tank that accumulates the cooling energy with the results of the numerical calculation. The results showed that the numerical model provided good results. Validity evaluation of Half cycle figure of merit of charging and discharging process has been analyzed. For both tanks, for all the flows rate it goes over 95%. It was found that during the charging and discharging procesess a significant conduction impact comes up with lower flows, which increases an outlet width of the thermocline. A flow rate impact onto the efficiency of discharge process for Tank 1 and Tank 2 at outlet water temperature 96 °C was analyzed. For Tank 1 ranges from 90.4 to 91.29%, and for Tank 2 ranges between 90.67 and 92.77%, depending on the water flow rate. With both tanks, the results showed that it is better to keep the flow rate low at the beginning of the discharge process.