Abstract
This paper investigates the potential of integrating the emerging Joule Cycle Heat Pump (JCHP) to recover and upgrade process waste heat, improving process energy efficiency. Existing heat pump applications for waste heat recovery mostly adopt the two-phase vapour compression heat pump. This reliance on latent heat transfer is efficient for applications where the heat capacity flow rates of the heat sources and sinks are high, resulting in nearly flat temperature-enthalpy profiles. However, for applications with low heat capacity flowrates, applying vapour compression heat pumps results in a significant temperature lift, decreasing the Coefficient of Performance (COP). The present study simulates the JCHP using four different working fluids – Ar, CO2, N2, and Ne and optimises the operating parameters to obtain the maximum COP of the JCHP. The JCHP has good prospects for serving industrial processes with significant temperature changes. The developed model is applied to target the integration of the JCHP with an industrial milk spray dryer case study. The method is based on Pinch Analysis and customised to the JCHP, evaluating the process type and energy profile, for which the JCHP integration is beneficial. The COP of the integrated system using JCHP is 3.3, which is higher than COP (2.7) of the two-phase heat pump.
