Humidifier is an important component in air humidification-dehumidification desalination plant for fresh water production. Liquid to air flow rate ratio is optimization is reported for an industrial cooling towers but for an air humidifier it is not addressed. The current work is focused on the design and analysis of an air humidifier for solar desalination plant to maximize the yield with better humidification, using finite difference method (FDM). The outlet conditions of air from the humidifier are theoretically predicted by FDM with the given inlet conditions, which will be further used in the design calculation of the humidifier. Hot water to air flow rate ratio and inlet hot water temperature are identified as key operating parameters to evaluate the humidifier performance. The maximum and optimal values of mass flow rate ratio of water to air are found to be 2.15 and 1.5 respectively using packing function and Merkel Integral. The height of humidifier is constrained to 1.5 m and the diameter of the humidifier is found as 0.28m. The performance of humidifier and outlet conditions of air are simulated using FDM and compared with experimental results. The obtained results are within an agreeable range of deviation. © 2017 Published under licence by IOP Publishing Ltd.

Chiranjeevi C

Department of Thermal and Energy Engineering

School of Mechanical Engineering

Vellore Campus

Srinivas T.

Fulltext

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Design and development of an air humidifier using finite difference method for a solar desalination plant

IOP Conference Series: Materials Science and Engineering

Humidification–dehumidification (HDH) desalination works based on a water cycle principle and involves air humidification and condensation (dehumidification). The cooling of humid air with chilled water increases the desalination and results in cold air suitable for air conditioning process. The merits of the proposed HDH desalination and cooling are not analyzed and compared in the literature. Therefore, the performance results of HDH with normal water (current technology) and HDH with chilled water (proposed idea) are compared to highlight the merit of this cycle. The combined cycle for desalination and cooling has been solved thermodynamically with psychrometric properties. The results are validated with a laboratory experimental setup. The examined operational process conditions are hot water inlet temperature, efficiency of humidifier, and vapor absorption refrigerator's (VAR's) evaporator exit temperature. The focused results are desalination, cooling and energy utilization factor (EUF). The comparative study recommends the use of chilled water in the final stage. The two stage desalination with dehumidification by normal water in the first stage and chilled water in combined two stages improves the cycle EUF from 0.18 to 0.33. Out of 300 W of cooling generation, 100 W is used for dehumidification and the remaining 200 W is available for air conditioning process at 15 N⋅m3 h−1 of air. © 2017 Elsevier Ltd and IIR

International Journal of Refrigeration

Augmented desalination with cooling integration

2016 International Conference on Energy Efficient Technologies for Sustainability (ICEETS)

Performance evaluation of honeycomb structured PVC packed humidifier in a Humidification-Dehumidification Desalination Plant

This work evaluates a two-stage humidification-dehumidification (HDH) process for combined air cooling and desalination for fresh water production from salt water experimentally. A pilot scale plant is designed and constructed with 16 m2 solar collector area for salt water heating. The operational parameters identified are hot saline water supply to humidifiers and it's temperature. The saline water is heated in a solar water heater (SWH) and supplied to the two humidifiers and air preheaters. Main performance parameters i.e. desalinated water generation, cooling effect and energy utilization factor (EUF) of the plant is studied in the light of hot water inlet temperature and its flow rate. It is observed that a maximum of 2.5 LPH of fresh water is produced at a water and air flow rates of 300 LPH and 10 m3/hr respectively. At low inlet water temperatures the resulted cooling effect is more compared with high temperatures and an average of 120 W of cooling effect is produced. The energy utilization factor (EUF) of combined two stage desalination and cooling plant is more compared with individual single stage plants and an average value of 0.4 is attained for combined plant. On overall basis, maximum possible water flow rate in humidifier and also high temperatures are recommended to yield more desalination output. © 2016 The Authors.

Energy Procedia

Experimental Analysis of Augmented Desalination by Cooling Integration

Humidification-dehumidification (HDH) desalination is a simple and cost effective solution to convert the saline water into desalinated water. In current work, desalination yield has been augmented with two stage HDH integrated cooling plant. A pilot plant has been developed and analyzed with experimental and simulation studies. The identified operational variants are hot saline water supply to humidifiers and its inlet temperature. The saline water is heated in a solar water heater (SWH) and supplied to two humidifiers and two air preheaters. The simulated results developed for subsystems are validated with the experimental readings. Desalination yield is not satisfactory level at lower water temperature in the first stage plant but there is no such limitation in the second stage operation. Nearly 1.5 LPH of desalinated water is resulted at 15m3/h of air. The energy utilization factor (EUF) of two stage plant is concentrated at higher side compared to the single stage plant's EUF. The increased flow of saline water in humidifiers and its high temperature is favoring the desalination output but with a penalty in cooling effect. © 2015 Elsevier B.V.

Desalination

Experimental and simulation studies on two stage humidification–dehumidification desalination and cooling plant

Two or more than two outputs from a single source result an overall high energy utilization factor (EUF) compared to the single output system. In this work, two stage humidification and dehumidification (HDH) desalination system has been extended with cooling system integration. Solar flat plate collector and concentrating collector are selected respectively for HDH desalination and single effect vapor absorption refrigeration (VAR) plant. The cooling after desalination increases the yield of distillation compared to without its integration. The sequence of operations in the combined plant is first stage air preheatinghumidification-dehumidification, second stage air preheating-humidification-dehumidification and final cooling of air with chilled water. The work is aimed on thermodynamic study for maximization of EUF for cycle and plant. The role of humidifier efficiency, its effectiveness, hot water temperature and chilled water temperature (by varying VAR evaporator temperature) has been studied on integrated performance. The resulted distilled water is 670 LPH with 75kW cooling at unit volume of air (1m3/s). The cycle EUF and plant EUF are 0.58 and 0.33 respectively. © 2014 Elsevier B.V.

Journal	Data powered by TypesetIOP Conference Series: Materials Science and Engineering
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ISSN	1757-8981
Open Access	No