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Balaji Kumar

Bio: Balaji Kumar is an academic researcher from Anna University. The author has contributed to research in topics: Thermal energy & Coefficient of performance. The author has an hindex of 1, co-authored 1 publications receiving 4 citations.

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TL;DR: In this paper, the waste heat available in the exhaust of the steam turbine and beneficial use of waste heat was described. But, the inlet temperature of the coolant should be less for achieving higher coefficient of performance.
Abstract: 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.

6 citations


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TL;DR: In this article, a transient 2-D numerical modeling of LiBr/H2O solution pool boiling in the generator of the absorption chiller was carried out using the two-phase Eulerian-Eulerian approach, extended Rensselaer Polytechnic Institute boiling model and renormalization group k-e turbulence model.
Abstract: Investigating the pool boiling process in the absorption chiller generator by studying the valid parameters may enhance the chiller’s COP. In the present study, the transient 2-D numerical modelling of LiBr/H2O solution pool boiling in the generator of the absorption chiller was carried out using the two-phase Eulerian-Eulerian approach, extended Rensselaer Polytechnic Institute boiling model and renormalization group k-e turbulence model. The numerical model was applied on three types of the bare, notched fin, and low fin tubes to investigate the effect of using fin on the boiling heat transfer rate in the generator of the absorption chiller and comparing it with the bare tube. Moreover, the numerical results were compared with the data obtained from the previous experimental studies to validate numerical modelling. A good agreement was achieved between numerical and experimental results. The results showed the evaporation mechanisms in the microlayer, evaporation in the three-phase (liquid-vapor-solid) contact line, and transient conduction the superheat layer for constant thermal heat flux and the three surfaces of the copper tube within a specific period from the boiling point of LiBr/H2O solution. The results also showed that the use of a notched fin-tube and low fin tube increases the non-homogeneous nucleation rate, causes the solution boil earlier than the bare tube, and reduces the required thermal energy in the generator of an absorption chiller.

5 citations

Journal ArticleDOI
TL;DR: In this article, the penalty factor method was used to minimize the exergy destruction rate at the absorber of a double-effect vapor absorption system using the optimized generator against the optimal generator.
Abstract: 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.

4 citations

Journal ArticleDOI
TL;DR: In this article , the penalty factor method was used to minimize the exergy destruction rate at the absorber using the optimized generator temperature of the double-effect vapor absorption system by considering absorber, evaporator, and condenser temperatures.
Abstract: 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.

4 citations

Journal ArticleDOI
TL;DR: In this article , an energy and economic analysis and modelling of the absorption chiller network were carried out to have a deep understanding of the network and investigate the effects of operating conditions, and the particle swarm optimization search algorithm was employed to find an optimum levelized total costs of the plant.
Abstract: Absorption chillers are one of the most used equipment in industrial, commercial, and domestic applications. For the places where high cooling is required, they are utilized in a network to perform the cooling demand. The main objective of the current study was to find the optimum operating conditions of a network of steam absorption chillers according to energy and economic viewpoints. Firstly, energy and economic analysis and modelling of the absorption chiller network were carried out to have a deep understanding of the network and investigate the effects of operating conditions. Finally, the particle swarm optimization search algorithm was employed to find an optimum levelized total costs of the plant. The absorption chiller network plant of the Marun Petrochemical Complex in Iran was selected as a case study. To verify the simulation results, the outputs of energy modelling were compared with the measured values. The comparison with experimental results indicated that the developed model could predict the working condition of the absorption chiller network with high accuracy. The economic analysis results revealed that the levelized total costs of the plant is 1730 $/kW and the pay-back period is three years. The optimization findings indicated that working at optimal conditions reduces the levelized total costs of the plant by 8.5%, compared to the design condition.

3 citations

Journal ArticleDOI
TL;DR: In this article, an energy and economic analysis and modeling of the absorption chiller network were carried out to have a deep understanding of the network and investigate the effects of operating conditions.
Abstract: Absorption chillers are one of the most used equipment in industrial, commercial, and domestic applications For the places where high cooling is required, they are utilized in a network to perform the cooling demand The main objective of the current study was to find the optimum operating conditions of a network of steam absorption chillers according to energy and economic viewpoints Firstly, energy and economic analysis and modeling of the absorption chiller network were carried out to have a deep understanding of the network and investigate the effects of operating conditions Finally, the particle swarm optimization search algorithm was employed to find an optimum levelized total costs of the plant The absorption chiller network plant of the Marun Petrochemical Complex in Iran was selected as a case study To verify the simulation results, the outputs of energy modeling were compared with the measured values The comparison with experimental results indicated that the developed model could predict the working condition of the absorption chiller network with high accuracy The economic analysis results revealed that the levelized total costs of the plant is 1730 $/kW and the payback period is three years The optimization findings indicated that working at optimal conditions reduces the levelized total costs of the plant by 85%, compared to the design condition

3 citations