Retrofit of a Galvanisation Plant using Advanced Heat Pump Bridge Analysis

Abstract

This paper addresses the need for retrofit approaches that simultaneously improve heat integration through heat exchangers and heat pumps considering process restrictions and an economic analysis framework. For this purpose, the Heat Pump Bridge Analysis method is extended to include the targeting of economic break-even points for heat pumping and the investigation of different modelling levels. For evaluation purposes, the case study of an electroplating process is used where retrofit safety-relevant process restrictions must be considered. The results include two heat recovery systems with one or two heat exchangers according to this grey box approach. The concept with only one heat recovery exchanger fulfils the economic requirements for full supply by heat recovery and heat pumps with an electricity-to-reference price ratio of 1.8 compared to the concept with two heat recovery exchangers or the white box approach, which ignores the process restrictions.