Computational model of a PCM heat exchanger for on farm cooling of milk.

New Zealand’s dairy industry accounts for 30% of the country’s total exports, earning $14 billion NZD per year. Recently the New Zealand Government has approved a set of milk cooling regulations that must be implemented by 2018. These regulations will require existing milk cooling systems to be more efficient and provide higher cooling rates. In this paper we investigate through simulations the feasibility of using Phase Change Material (PCM) heat exchangers to increase the milk cooling capacity. This is done by modelling a packed bed high conductivity PCM heat storage system. The feasibility of a PCM based refrigeration system is significant as 30% of the energy used in a dairy farm is spent for milk cooling. PCM technology allows operators to reduce operating expenses by charging the PCM system at night, under cheaper power rates to cool milk during the day at no cost. Such technology may be of great commercial interest.