Performance comparison of six solar-powered air-conditioners operated in five places

Abstract

International audienceSix solar-powered air-conditioners, based on four principles (LiBr + H2O liquid sorption, silicagel + water solid sorption, BaCl2 + NH3 thermochemical reaction, and desiccant + humid air open cycles) have been operated in five places (from the low-altitude Alps to a tropical island including Mediterranean Sea shore). A common experimentation procedure was applied over months, except for some cases, and during several years. Data were recorded, gathered, and analyzed similarly for the six units. Is established a sound framework based on relevant quantities, some non-dimensional and others dimensional but referred to relevant scales, with the purpose that direct comparison of results is sensible. Similarly, are defined the sub-units to be considered for further analysis. This framework is applied to (i) data averaged over long periods, and (ii) data obtained on one single day with given insolation. Comprehension obtained from comparison in that framework gives access to notions as different as (i) fundamental differences between systems, (ii) aging of components, and (iii) non-linearity of the basic operation of such solar-powered units. The theoretical analysis of this non-linearity is developed. The framework established in this article could thus be used for comparing other solar-powered processes

Simulation of a Low Capacity Absorption Cooling System for Indoor Air-Conditioning

“…Simplified scheme of the installation [8] In the proposed air conditioning system, the electricity consumption is due to the Rotartica machine itself (400 W), the cooling tower (370 W) and the pumps on the heat rejection circuit and the generator circuit (200 W). The electricity consumption for the distribution of the chilled water and the fan-coil unit is not taken into account, since it is not directly related to cold production [6].…”

“…Indeed, by using Eq. (4) (6) Moreover, the maximum potential value for the PER in the solar assisted system can be derived from Eq. (4) and Eq.…”

“…Indeed, the cooling demand and the availability of solar irradiation are positively correlated in time and intensity. Moreover, the temperature level required at the generator is well adapted to the common performance of flat-plate or evacuated-tube solar collectors, the cost of which is nowadays relatively low [6]. A review on solar assisted thermally driven technologies is presented in [7].…”

The size of sorbents in low pressure sorption or thermochemical energy storage processes

“…Currently, thermochemical or sorption processes result in the emergence of various applications, such as seasonal solar thermal storage for building heating or domestic hot water [1,2], electricity fluctuation management in combination with micro CHP (combined heat and power) [3], e-mobility [4], high temperature power plants [5], industrial applications [6,7], vehicle thermal energy storage [8], heat transportation [9], solar heating and cooling [10], heat transformation with adjustable equilibrium temperature for various temperature levels [11], etc.…”

Development of a dynamic artificial neural network model of an absorption chiller and its experimental validation

“…This system must face a paradox: the more air-conditioners installed in a city, the more heat is released to urban atmosphere, and the more ambient air temperature increases, decreasing the performance efficiency of airconditioners and increasing the cooling load of building [1]. In fine, peak electricity demand for cooling must be tripled [2].…”