Numerical Analysis of Heat and Mass Transfer in an Annular Porous Adsorber for Solar Cooling System

2010 ◽  
Vol 297-301 ◽  
pp. 802-807
Author(s):  
Nadia Allouache ◽  
Rachid Bennacer ◽  
Salahs Chikh ◽  
A. Al Mers
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
System Performance ◽  
Technology Development ◽  
Cooling System ◽  
Coefficient Of Performance ◽  
Cooling Systems ◽  
Solar Cooling ◽  
Adsorbed Quantity ◽  
Solar Cooling System

The present study deals with a solid adsorption refrigerator analysis using activated carbon/methanol pair. It is a contribution to technology development of solar cooling systems. The main objective consists to analyse the heat and mass transfer in an annular porous adsorber that is the most important component of the system. The porous medium is contained in the annular space and the adsorber is heated by solar energy. A general model equation is used for modelling the transient heat and mass transfer. Effects of the key parameters on the adsorbed quantity, the coefficient of performance, and thus on the system performance are analysed and discussed.

Mass Nature of Heat and Its Application VII: Coupled Heat and Mass Transfer Optimization Based on the Entransy Theory

2010 ◽  
Author(s):  
Qun Chen ◽  
Moran Wang ◽  
Ning Pan ◽  
Zeng-Yuan Guo
Keyword(s):  
Mass Transfer ◽  
Thermal Resistance ◽  
Heat And Mass Transfer ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Entransy Dissipation ◽  
Cooling Systems ◽  
Entransy Theory ◽  
Transfer Processes ◽  
Mass Transfer Processes

Using the analogy between heat and mass transfer processes, the recently developed entransy theory is extended in this paper to tackle the coupled heat and mass transfer processes so as to analyze and optimize the performance of evaporative cooling systems. We first introduce a few new concepts including the moisture entransy, moisture entransy dissipation, and the thermal resistance in terms of the moisture entransy dissipation. Thereinafter, the moisture entransy is employed to describe the endothermic ability of a moist air. The moisture entransy dissipation on the other hand is used to measure the loss of the endothermic ability, i.e. the irreversibility, in the coupled heat and mass transfer processes, which consists of three parts: (1) the sensible heat entransy dissipation, (2) the latent heat entransy dissipation, and (3) the entransy dissipation induced by a temperature potential. And then the new thermal resistance, defined as the moisture entransy dissipation rate divided by the squared refrigerating effect output rate, is recommended as an index to effectively reflect the performance of the evaporative cooling system. Meanwhile, a minimum thermal resistance law for optimizing the evaporative cooling systems is developed. In the end, several direct and indirect evaporative cooling processes are analyzed to illustrate the applications of the proposed concepts.

Modeling of Heat and Mass Transfer in an Annular Adsorber for Solar Cooling Machine: Performance Coefficients

2011 ◽  
Vol 312-315 ◽  
pp. 641-646
Author(s):  
Nadia Allouache ◽  
Rachid Bennacer ◽  
Salahs Chikh ◽  
A. Al Mers ◽  
N. Mimouni
Keyword(s):  
Mass Transfer ◽  
Porous Medium ◽  
Heat And Mass Transfer ◽  
General Model ◽  
Model Equation ◽  
Annular Space ◽  
Adsorption Phenomenon ◽  
Solar Cooling ◽  
Machine Performance ◽  
Adsorbed Quantity

The primary aim of this study is to simulate numerically the heat and mass transfer characteristics in the annular adsorber that is the most important component of the solar cooling machine, and to evaluate the solar and thermal coefficients of performance as an optimisation criterion of the system, for different adsorbent/adsorbate pairs. The porous medium constituted of the adsorbent/adsorbate is contained in the annular space and it is heated by solar energy. A general model equation is used for modeling the transient heat and mass transfer. The adsorption phenomenon is described by using different models of solid-adsorbate equilibrium. Effects of the key parameters on the adsorbed quantity, the generating temperature, the performance coefficients and thus on the system performances are investigated.

Methodology to Determine Cost and Performance Goals for Active Solar Cooling Systems

1983 ◽  
Vol 105 (2) ◽  
pp. 217-223
Author(s):  
M. L. Warren ◽  
M. Wahlig
Keyword(s):  
Thermal Performance ◽  
Return On Investment ◽  
Energy Savings ◽  
Cooling System ◽  
Cooling Systems ◽  
Solar Cooling ◽  
And Performance ◽  
Air Conditioning Systems ◽  
Solar Cooling System ◽  
Year 2000

Economic and thermal performance analyses of typical residential and commercial active solar cooling systems are used to determine cost goals for systems to be installed between the years 1986 and 2000. Market penetration for heating, ventilating, and air conditioning systems depends on payback period, which is related to the expected real return on investment. Postulating a market share for solar cooling systems increasing to 20 percent by the year 2000, payback and return on onvestment goals as a function of year of purchase are established. The incremental solar system cost goal must be equal to or less than the 20-year present value of future energy savings, based on thermal performance analysis, at the desired return on investment. Methods for achieving these cost goals and expected solar cooling system costs will be discussed.

Simulation Study of the Heat and Mass Recovery on the Performance of Adsorption Cooling Systems

2014 ◽  
Author(s):  
K. C. Chan ◽  
C. Y. Tso ◽  
Christopher Y. H. Chao
Keyword(s):  
System Performance ◽  
Heat Recovery ◽  
Cooling System ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Cooling Systems ◽  
Heating And Cooling ◽  
Adsorption Cooling System ◽  
Heat And Mass Recovery ◽  
Mass Recovery

In this study, simulation was conducted to investigate the effect of mass recovery, heat recovery, pre-heating and pre-cooling time on the system performance of a double-bed adsorption cooling system. Pressures of different system components were considered in the simulation. The adsorbent-adsorbate pair used was silica-gel and water. The heating and cooling temperatures were selected to be 85°C and 27°C respectively. Both the adsorption and desorption phase times were set at 15 minutes. The coefficient of performance (COP) and specific cooling power (SCP) were used to quantify the performance of the system. From the simulation, the basic cycle provided COP and SCP of 0.20 and 40.9W/kg respectively. By conducting heat recovery for 120 seconds, the system COP was largely increased by 99% to 0.40 compared to the basic cycle. The SCP was also increased to 42.3W/kg. Mass recovery, however, did not have too much effect on the system performance. The COP and SCP only increased by 4.5% and 3.9% respectively when conducting mass recovery for 4.7 seconds. For conducting heat and mass recovery, the COP and SCP were increased to 0.36 and 44.68W/kg, respectively. Pre-heating and pre-cooling can also be beneficial in improving both COP and SCP. The COP and SCP were increased by 14.5% and 10.1% respectively, to 0.23 and 45.0W/kg by conducting pre-heating and pre-cooling for 50.3 seconds. The combinations of these processes were also studied. It is suggested heat and mass recovery then pre-heating and pre-cooling should be conducted to improve COP and SCP. The improvements showed 31.2% for COP, increasing to 0.27, and 11.9% for SCP, increasing to 45.7W/kg.

scholarly journals Small Scale Solar Cooling Unit in Climate Conditions of Latvia: Environmental and Economical Aspects

2010 ◽  
Vol 4 (-1) ◽  
pp. 47-52
Author(s):  
Dzintars Jaunzems ◽  
Ivars Veidenbergs
Keyword(s):  
Cooling System ◽  
Electricity Consumption ◽  
Economic Feasibility ◽  
Point Of View ◽  
Small Scale ◽  
Cooling Systems ◽  
Climate Conditions ◽  
Solar Cooling ◽  
Cooling Unit ◽  
Solar Cooling System

Small Scale Solar Cooling Unit in Climate Conditions of Latvia: Environmental and Economical Aspects The paper contributes to the analyses from the environmental and economical point of view of small scale solar cooling system in climate conditions of Latvia. Cost analyses show that buildings with a higher cooling load and full load hours have lower costs. For high internal gains, cooling costs are around 1,7 €/kWh and 2,5 €/kWh for buildings with lower internal gains. Despite the fact that solar cooling systems have significant potential to reduce CO2 emissions due to a reduction of electricity consumption, the economic feasibility and attractiveness of solar cooling system is still low.

Review of Solar Sorption Cooling Research in the MENA Region

2016 ◽  
Author(s):  
Abdul Ahad Mohammad Iqbal ◽  
Ali Al-Alili
Keyword(s):  
Middle East ◽  
North Africa ◽  
Cooling System ◽  
Research Trends ◽  
Coefficient Of Performance ◽  
Mena Region ◽  
Solar Cooling ◽  
Absorption Chillers ◽  
Solar Cooling System ◽  
Sorption Cooling

This paper provides a brief overview of closed sorption cooling technologies, and highlights the research performed on them in the Middle East and North Africa region. The main findings are summarized and presented in tabulated and graphical forms. The reviewed studies are compared in terms of the working pair, the Coefficient of Performance, the normalized collector area, etc. The results show that the average cyclic Coefficient of Performance for the adsorption chillers was 0.41, whereas the average chiller Coefficient of Performance for the absorption chillers was 0.677. The research trends reveal that interest in solar sorption cooling was low in the 1980s and 1990s, and gradually increased during the 2000s. In addition, the most installed solar cooling system in the Middle East and North Africa region is utilizing absorption cycles.

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