Assessment of Energy, Environmental and Economic Performance of a Solar Desiccant Cooling System with Different Collector Types

Abstract

Desiccant-based air handling units can achieve reductions in greenhouse gas emissions and energy savings with respect to conventional air conditioning systems. Benefits are maximized when they interact with renewable energy technologies, such as solar collectors. In this work, experimental tests and data derived from scientific and technical literature are used to implement a model of a solar desiccant cooling system, considering three different collector technologies (air, flat-plate and evacuated collectors). Simulations were then performed to compare the energy, environmental and economic performance of the system with those of a desiccant-based unit where regeneration thermal energy is supplied by a natural gas boiler, and with those of a conventional air-handling unit. The only solution that allows achieving the economic feasibility of the solar desiccant cooling unit consists of 16 m 2 of evacuated solar collectors. This is able to obtain, with respect to the reference system, a reduction of primary energy consumption and of the equivalent CO2 emissions of 50.2% and 49.8%, respectively, but with a payback time of 20 years. OPEN ACCESSEnergies 2014, 7 6742

Analysis of a Solar Cooling System for Climatic Conditions of Five Different Cities of Saudi Arabia

“…The operating sequence for the return or regeneration air stream is as follows: (5-6) return air is cooled in the evaporative cooler to its saturation point; (6-7) cooled return air exchanges heat with hot process air in heat recovery wheel; (7)(8) air is heated to the required regeneration temperature using solar collector or auxiliary heater; (8-9) finally, hot air passes through the desiccant wheel to regenerate it. Saudi Arabia observes high values of global solar radians and long sunshine duration throughout the year [25,26].…”

“…The humid air has high partial vapor pressure while desiccant materials create an area of lower surface vapor pressure. This difference of vapor pressure causes transfer of moisture from air to the desiccant material [7]. The desiccant material is desired to have a low surface vapor pressure for better dehumidification of the air.…”

Parametric Analysis of Design Parameter Effects on the Performance of a Solar Desiccant Evaporative Cooling System in Brisbane, Australia

“…It has been found to be environmentally friendly, and in some circumstances economically beneficial, as it is able to improve indoor air quality while at the same time reducing energy consumption [1,2]. The basic solar desiccant cooling system generally combines the desiccant process with evaporative cooling.…”

“…They demonstrated that the system would achieve an annual coefficient of performance (COP) of 0.7, a 22% solar fraction (SF), 4.4 tonnes of greenhouse gas (GHG) emissions reduction, and 22 years payback by installing 10 m 2 solar collectors and 0.4 m 3 storage tank. Angrisani et al [2] assessed the energy, environmental, and economic performances of a solar desiccant-based air handling unit (AHU) with three types of collectors: solar air collector, flat plate collector, and evacuated tube collector. They found that energy and environmental benefits increased with the solar collector surface, but the thermo-economic performance was not in proportion to the solar collector surface.…”

Performance Evaluation of a Desiccant Dehumidifier with a Heat Recovery Unit

“…Silica gel is one of the common adsorbents because of its numerous advantages such as larger pores, larger surface area, and excellent dehumidification capability [1]. In fact, desiccant devices using silica gel as an absorbent have been widely used for dehumidification in many industrial areas [2] in addition to its use in air conditioning systems coupling with a heat source [3][4][5].…”