Chapter 5 - Multiple Effect Evaporation Vapor Compression

Abstract

This chapter analyzes the performance of multiple effect evaporation systems combined with various types of heat pumps. The analysis includes performance of the following systems: parallel feed multiple effect evaporation with thermal or mechanical vapor compression heat pumps; forward feed multiple effect evaporation with thermal, mechanical, absorption, or adsorption vapor compression heat pumps. The performance of the parallel feed systems is compared against industrial data. However, the forward feed system presents only results of system design, since there are no industrial units for these systems. Further, discussion focuses on modeling and performance analysis of the forward feed multiple effect evaporation with thermal vapor compression. The analysis included a step-by-step calculation method for the multiple effect evaporation- thermal vapor compression (MEE-TVC) system, detailed mathematical model, performance as a function of the top brine temperature and the number of effects, and comparison against the stand-alone forward feed MEE system. Results show an increase up to 50% in the thermal performance ratio and a similar decrease in the specific flow rate of cooling water.