An Analysis on the Increment of Coefficient of Performance of an On-Farm Direct Expansion Bulk Milk Cooler (DXBMC) Through the Use of a Raw Milk Pre-Cooler

Abstract

The performance of a direct expansion bulk milk cooler is influenced by various factors on the farm. This study presents an analysis on the increment of the coefficient of performance of an on-farm direct expansion bulk milk cooler (DXBMC) through the use of a raw milk pre-cooler during the milk cooling process. Accordingly, a data acquisition system (DAS) was designed and deployed to accurately measure the power consumption of the BMC and temperature of raw milk. The volume of milk produced per day was extracted from the daily records on the farm. Empirical models were used together with the experimental data to simulate the operation of the DXBMC if a pre-cooler was being used. The findings from the experimental study showed that through the use of raw milk pre-cooler, the average raw milk temperature delivered to the DXBMC will be 20.43°C. This leads to the COP of the DXBMC increasing by an average of 25% from 2.15 to 2.67. Increase in the milk volume led to an increase in the COP such that the peak period with higher milk volumes recorded a high COP increase of 16.21%. The use of a pre-cooler would lead to an average energy saving of 17,667.67 kWh in a year as well as 17.83 tCO2 will be avoided.