The pinch technology combined with a heat pump applied in a three-effect evaporator and energy-saving performance assessment

Abstract

This research investigated optimal energy utilization with pinch technology based on an actual gelatin production factory using a three-effect evaporator (TEE). A TEE is a well-known device used extensively when concentrating process fluid with large amounts of boiler steam. Under ideal energy use conditions, the exhaust heat can be recovered with the addition of a heat pump system. The study results showed that the original energy demand and discharge of the TEE were 1,736.2 and 1,733.2 kWh, respectively. Simulating the pinch technology use, the energy demand and discharge decreased to 1,531.5 and 1,527.7 kWh, respectively. When the heat pump was used to recover the exhaust heat, 324 kL per annum of fuel oil was saved, while electricity use increased 131 kWh. The total investment cost was 86,550 US$, but the total annual operation cost could save up to 166,421 US$. The net present value was estimated to be 544,316 US$ with a 5-year equipment operation. The investment expense could be completely recovered within a seven-month remuneration period.