Vapor absorption system powered by different solar collectors types: Cooling performance, optimization, and economic comparison

2018 ◽  
Vol 24 (6) ◽  
pp. 612-625 ◽  
Author(s):  
Vinay Kumar ◽  
Bhargav Pandya ◽  
Jatinkumar Patel ◽  
Vijay Matawala
Keyword(s):  
Performance Optimization ◽  
Solar Collectors ◽  
Absorption System ◽  
Cooling Performance ◽  
Vapor Absorption ◽  
Economic Comparison

EXERGY ANALYSIS OF A LiBr–H2O VAPOR ABSORPTION REFRIGERATION PLANT: A CASE STUDY

2014 ◽  
Vol 22 (02) ◽  
pp. 1450010 ◽  
Author(s):  
SANJEEV ANAND ◽  
ANKUSH GUPTA ◽  
SUDHIR KUMAR TYAGI
Keyword(s):  
Performance Optimization ◽  
Exergy Analysis ◽  
Heat Rate ◽  
Exergy Efficiency ◽  
Exergy Loss ◽  
Absorption Refrigeration ◽  
Actual System ◽  
Evaporator Temperature ◽  
Vapor Absorption ◽  
Vapor Absorption Refrigeration

This communication presents the energy and exergy analysis of an actual double effect steam powered LiBr – H 2 O vapor absorption refrigeration plant. Exergy loss, COP, exergy efficiency and heat rate for each component of the system are calculated. The effect of generator as well as evaporator temperature on the COP and exergy efficiency is evaluated and it is found that the irreversibility rate is highest in the generator while it is found to be the lowest in the case of absorber and condenser. It is also found that the COP of the system increases with the increase in the evaporator temperature while it is found to be reverse in case of exergy efficiency. Results revealed that average exergy loss is highest in the generator as compared to other components. The results obtained are helpful for designers to bring changes in the actual system for performance optimization and less wastage of energy. The study clearly explain the operational and maintenance problems in the machine and point out the areas of energy wastage which the operational engineer should look into for the optimum operation of the plant.

Solar Air Conditioning Systems With PCM Solar Collectors

Solar Energy ◽  
2002 ◽  
Author(s):  
Jorge E. Gonza´lez ◽  
Luis Humberto Alva S.
Keyword(s):  
Flat Plate ◽  
Thermal Performance ◽  
Air Conditioning ◽  
Lithium Bromide ◽  
Geographical Location ◽  
Solar Collectors ◽  
Absorption System ◽  
Air Conditioning System ◽  
Graphite Composite ◽  
Cooling Loads

This paper investigates the technical feasibility of using a compact, air-cooled, solar absorption air conditioning system when coupled to an innovative array of solar collectors. The particular absorption system of study is a single effect that uses lithium bromide and water as the absorbent and refrigerant fluid pair. The geographical location of interest is Puerto Rico and similar subtropical regions. The heat input to the absorption system generator is provided by an array of novels flat plate solar collectors that integrate the thermal storage component into them. The proposed collectors have a phase change material (PCM) integrated into them as a storage mechanism. The PCM-integrated solar collector eliminates the need of conventional storage tanks reducing cost and space. The present work uses a paraffin-graphite composite as the PCM to increase the conductivity of the PC matrix. The paraffin’s melting point is around 89°C that is appropriate for use in absorption systems. The mathematical model that describes the thermal process in the PCM is presented and differs from the analysis of conventional flat plate solar collectors. The proposed model for the PCM considers the temporal changes but not the spatial variations. The resulting set of equations for the fluid flow, the PCM, and the collector’s surface are solved simultaneously. Results for the collectors’ thermal performance are presented along with the effects of the composition of the PCM material. The thermal performance of an absorption machine coupled to an array of the proposed PCM’s solar collectors was investigated for nominal cooling capacities of 10.5, 14, and 17.5 kW. These cooling loads are suitable for a typical house or a small business building in Caribbean Islands. Computer simulations were conducted to evaluate the overall system’s performance when subjected to dynamic cooling loads. Within the computer model, heat and mass balances are conducted on each component of the system, including the solar collectors, the air-cooled condenser, and the air-cooled absorber. Comparisons are made with an absorption air conditioning system that uses a cooling tower with conventional flat plate collectors instead of air-cooled and PCM components. Useful information about physical dimensions of collectors, number of collectors needed, and efficiency of the overall system is presented.

Effect of Inlet Air Refrigeration on the Performance of Combined Cycle Power Plants

2004 ◽  
Author(s):  
G. Srivastava ◽  
R. Yadav
Keyword(s):  
Heat Source ◽  
Power Plants ◽  
Combined Cycle ◽  
Air Cooling ◽  
Specific Work ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Absorption System ◽  
Vapor Absorption ◽  
Gas Turbine Exhaust

In the present work an attempt has been made to study the effect of inlet air refrigeration on the performance of combined cycle power plants. The inlet air cooling for the chosen combined cycle configuration may be done by means of employing a refrigeration system such as vapor compression and vapor absorption system, which derive the energy input from the system itself. In the vapor absorption system, the input energy to generator is given by three possible heat source from the system namely from the gas turbine exhaust, steam bled from steam turbine and exhaust gas from the exit of heat recovery steam generator (HRSG). It has been observed that the vapor absorption system with HRSG exhaust as heat source to the generator is the better option followed by the vapor compression refrigeration system for compressor inlet air cooling. The cooled compressed inlet air up to 280K from 300K improves the plant specific work around 4% and plant efficiency around 0.39 percentage point for the combined cycle using vapor compression system.

scholarly journals Exergy destruction rate minimization in the absorber of a double effect vapor absorption system

2021 ◽  
pp. 222-222
Author(s):  
Muhammad Mushtaq ◽  
Muhammad Kamran ◽  
Haseeb Yaqoob ◽  
Muhammad Jamil ◽  
Muhammad Shafiq ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Energy Requirement ◽  
Double Effect ◽  
Cooling Capacity ◽  
Exergy Destruction ◽  
Absorption System ◽  
Destruction Rate ◽  
Penalty Factor ◽  
Vapor Absorption ◽  
Exergy Analyses

Despite the wide applications of multi-effect vapor absorption systems, their energy requirement is relatively higher. Also, their exergy analyses found in the literature reveal that the exergy destruction rate at the absorber is quite significant and has the potential for improvement in its energy efficiency. In this work, the exergy destruction rate at the absorber is minimized using the penalty factor method against the optimized generator temperature of the double-effect vapor absorption system by considering absorber, evaporator, and condenser temperatures into consideration. Modeling of the double-effect vapor absorption system was performed using a thermodynamic toolbox in SIMULINK. The present model employed a refrigerant heat exchanger to enhance the system cooling capacity. The Liquid-vapor ejector valve at the absorber also improved the mixing of the solution and refrigerant vapor resulting in lower irreversibility of the system. Results show that the coefficient of a performance increase by 2.4 % with refrigerant heat exchanger and exergy loss at absorber decrease by 9.4 % with ejector. The optimum performance was seen at the condenser and evaporator temperatures of 308.8 K and 278.1 K, respectively with an 8.2 % improvement in exergetic efficiency. Finally, it is concluded that the multi-effect absorption system shows better performance by minimizing the irreversibility.

scholarly journals Thermodynamic analysis of a single effect lithium bromide water absorption system using waste heat in sugar industry

2018 ◽  
Vol 22 (1 Part B) ◽  
pp. 507-517
Author(s):  
Balaji Kumar ◽  
Iniyan Selvarasan ◽  
Gurubalan Annadurai ◽  
Senthilkumar Ramalingam
Keyword(s):  
Steam Turbine ◽  
Energy Savings ◽  
Waste Heat ◽  
Sugar Industry ◽  
Operating Parameter ◽  
Coefficient Of Performance ◽  
Inlet Temperature ◽  
Absorption System ◽  
Beneficial Use ◽  
Vapor Absorption

Energy analysis plays a vital role in the industry due to the use of electrical energy, global warming, and economy crises. This paper describes the waste heat available in the exhaust of the steam turbine and beneficial use of the waste heat. The sugar industry steam turbine exhaust carries enthalpy of steam at 2500 kJ/kg, this thermal energy can be put into beneficial use as the heat source to the vapor absorption refrigeration system to compensate energy required for DC thyrist motor, and this can also be used for cold storage. Energy savings in terms of cost and fuels are calculated. Investigation on the heat and mass transfer in evaporator has been carried out in vapor absorption system by varying the operating parameter. Less circulation ratio is required to increase the coefficient of performance. The inlet temperature of the coolant should be less for achieving higher coefficient of performance.

Sign in / Sign up

Export Citation Format

Share Document