A NUMERICAL STUDY ON THE EFFECTS OF OIL CONTAMINATION ON FALLING FILM HEAT TRANSFER OVER HORIZONTAL TUBE IN A HEAT PUMP

In the late period of oilfield exploit, the oilfield production water contains large amount of high temperature water the thermal energy of which should be recovered. The sewage source heat pump system (SSHP) has been widely used for this energy recovery, improving the energy utilization efficiency. However, the heat transfer and flow characteristics of oily wastewater spraying in the heat exchanger are different from the ordinary sewage heat pump system. In this paper, a three-dimensional numerical model was established for a spraying heat exchanger in the oily sewage source heat pump system, and a mixture of water and glycerin was used to simulate the oily wastewater. The VOF model was used to simulate the gas-liquid flow of the spray falling film of oily wastewater over a horizontal tube in the heat exchanger, and the effects of different glycerin content and spray density on heat transfer.