Library Subscription: Guest
8th Thermal and Fluids Engineering Conference (TFEC)
March, 26-29, 2023, College Park, MD, USA

THERMODYNAMIC PERFORMANCE OF A HUMIDIFICATIONDEHUMIDIFICATION UNIT INTEGRATED WITH EJECTOR REFRIGERATION CYCLE FOR COOLING ENERGY AND FRESHWATER PRODUCTION

Get access (open in a dialog) pages 923-932
DOI: 10.1615/TFEC2023.esy.045870

Abstract

Producing cooling energy and freshwater using environmentally friendly systems is inevitable to achieve the ambitious goals of the federal sustainability plan, which aims to reach zero emissions in buildings by 2050. Among several cooling and desalination technologies, ejector refrigeration cycle (ERC) and humidificationdehumidification (HDH) desalination unit have good potential to deliver cooling energy and freshwater, respectively, at low cost using low-grade thermal energy. In this paper, we propose an integration between a waterheated humidification-dehumidification (HDH) desalination cycle and an ejector cooling cycle to produce freshwater and cooling energy simultaneously. The seawater is heated to drive the HDH cycle, while a portion of it is evaporated and used as motive steam for the ejector cycle. The ejector cycle is designed to produce cooling power at a temperature range from 5 to 15 °C for cooling building applications and freshwater as well. Therefore, both cycles can produce freshwater. The proposed cycle is equipped with a three-way valve to match the cooling power and freshwater to serve a certain number of persons. A thermodynamic model is built and validated to study the performance of the proposed cycle at different operating parameters. It is found that identifying the optimal seawater-to-air mass flow rate ratio is critical to achieve maximum energy efficiency. This value is found to be dependent on the operating conditions. The results provide guidelines for designing and building an efficient HDH/ejector cycle that could be powered by solar energy or waste heat.