VAPOUR COMPRESSION SYSTEMS

Vapour Compression Systems



Vapour Compression Systems

Introduction

Water is the essence of life. Civilizations in the past and the present revolve around fresh water resources for supply of all human needs. Availability of fresh water as well as its quality a¤ects the welfare of societies and human activities. Although, water covers 70% of the earth surface with a total amount of 14106 km3, only 25% of this volume is fresh water (Boyce, 2007, 43).

The majority of this water, about 70%, is locked frozen in the icecaps of Antarctica and Greenland. Most of the remaining amount, 29%, is also inaccessible for human use, where it exist in the form of soil moisture and in deep aquifers as ground water.

For this paper will use the following research articles:

Analysis of the variation mechanism in the main energetic parameters in a single-stage vapour compression plant by Cabello and Torella.

Performance of vapor compression systems with compressor oil flooding and regeneration by Ian Bell.

Simplified steady-state modelling of a single stage vapour compression plant. Model development and validation by Cabello and Torella.

The impact of fouling on performance of a vapor compression refrigeration system with integrated mechanical sub-cooling system by Bilal Ahmed Qureshi.

Theoretical analysis of a vapour compression refrigeration system with R502, R404A and R507A by Akhilesh Arora

This leaves a small amount, approximately 1%, accessible for human use. Though, it is assumed that this amount is sufficient to support all life on the plant, its not evenly distributed and it is not available in sufficient quantities when or where the need arise. At present, more than 40% of the world population live in environments with limited fresh water resources or with sufficient supply but of low quality.

Current forecast for future outlook of fresh water resources is bleak. It is expected that more than 67% of the world population will be faced with shortages in the fresh water supply and pollution of the available limited resources. This situation will be a result of rapid population growth, changes in the life style, expansion of uncontrolled and congested urban areas, and increase in the production volume of industrial activities. In many locations, such as the Gulf area, the only available solution for fresh water supply is desalting of sea and brackish water.

The challenges facing the engineers and the scientists is the reduction of the water cost produced by desalination. This is necessary to supply many countries suffering from water shortage but cannot afford the high cost of desalinated water (Lipski, 2000, 254).

We believe very strongly, that, all the people, irrespective, of their social and economical status or stage of development, have the right for access of fresh drinking water with standard quality and sufficient quantities to meet their demands. Single-effect desalination processes are suitable for remote and small population areas. The single-effect systems are based on various types of vapour-compression techniques, which include mechanical compressors, steam jet ejectors, solute water vapour absorption, and solidwater vapour adsorption. The single effect mechanical vapour-compression desalination process (MVC) is the most ...