Liquid desiccant based two-stage evaporative cooling system using reverse osmosis (RO) process for regeneration

This paper presents preliminary findings of the energy analysis of a cooling system with multistage evaporative coolers using liquid desiccant dehumidifier between the stages. The proposed evaporative cooling system utilizes the air humidity for cooling in humid areas and requires no additional water supply. The major energy requirement associated with this cooling system is the energy for regenerating the weak liquid desiccant. In this paper two types of energy namely thermal energy as well as mechanical energy are considered for regeneration. For thermal energy, the heat input for regeneration is supplied from the conventional energy sources such as a simple line heater. Reverse osmosis (RO) process is considered for regeneration by mechanical energy and MFI zeolite membrane is proposed for separation of water from the weak desiccant solution. Energy analysis has been carried out for both methods of regeneration. The results show that the energy consumption is about 25% less for the mechanical regeneration system with 3 % recovery than the thermal energy regeneration system to increase the desiccant solution temperature of 22°C. The COP of the proposed cooling system is defined as the cooling effect by the mass rate of water evaporated in the system divided by the amount of energy supplied to the system, that is, the COP is independent of the energy source.

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Impact of PV/T system on energy savings and CO2 emissions reduction in a liquid desiccant-assisted evaporative cooling system

Advanced Engineering and Technology ◽

10.1201/b16699-8 ◽

2014 ◽

pp. 45-50

Keyword(s):

Co2 Emissions ◽

Energy Savings ◽

Cooling System ◽

Evaporative Cooling ◽

Emissions Reduction ◽

Liquid Desiccant ◽

Evaporative Cooling System ◽

T System

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Two Stage Evaporative Cooling of Residential Building Using Geothermal Energy

Journal of Engineering ◽

10.31026/j.eng.2019.04.03 ◽

2019 ◽

Vol 25 (4) ◽

pp. 29-44

Author(s):

Ali Hammoodi Mahdi Alhosainy ◽

Issam Mohammed Ali Aljubury

Keyword(s):

Groundwater Flow ◽

Temperature Difference ◽

Geothermal Energy ◽

Cooling System ◽

Evaporative Cooling ◽

Residential Building ◽

Two Stage ◽

Second Stage ◽

Direct Evaporative Cooling ◽

Evaporative Cooling System

The weather of Iraq has longer summer season compared with other countries. The ambient temperature during this season reaches over 50 OC which makes the evaporative cooling system suitable for this climate. In present work, the two-stage evaporative cooling system is studied. The first stage is indirect evaporative cooling (IEC) represented by two heat exchangers with the groundwater flow rate (5 L/min). The second stage is direct evaporative cooling (DEC) which represents three pads with groundwater flow rates of (4.5 L/min). The experimental work was conducted in July, August, September, and October in Baghdad. Results showed that overall evaporative efficiency of the system (two coils with three pads each pad of 3cm) reach to 167 % with the temperature difference between ambient and supply is 26.2oC. While it reached 122.7% (one coil with three pads ) with the temperature difference between ambient and supply is 16OC and reduced to 84.88% and 84.36% for IEC and DEC respectively.

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