Thermodynamic Investigation of Integrated Air Cycle Refrigeration Systems

2017 ◽  
Vol 25 (02) ◽  
pp. 1750016
Author(s):  
Hamed Shoul ◽  
Mehran Ameri ◽  
S. M. Hojjat Mohammadi
Keyword(s):  
Waste Heat ◽  
Solid Oxide ◽  
Energy Utilization ◽  
Second Law ◽  
System Efficiency ◽  
Prime Mover ◽  
Absorption Chiller ◽  
Thermodynamic Investigation ◽  
Utilization Factor ◽  
Absorption Section

An analysis of air cycle refrigeration (ACR) systems based on the first and second laws of thermodynamics has been carried out. Cooling the gas cooler outlet enhances the system efficiency, hence the use of integrated refrigeration systems (IRSs). The IRS consists of an ACR, an absorption chiller and a prime mover. The waste heat from the prime mover operates the absorption chiller, which provides additional cooling that is used to cool down the air exiting the gas cooler. LiBr-H2O and NH3-H2O are used as fluid pairs in absorption section. The prime mover can either be gas turbine or solid oxide fuel cell (SOFC). Results indicate that an IRS with NH3-H2O and two recuperators has a better first and second law efficiency compared to other considered systems. It is also concluded that the energy utilization factor and second law efficiency are higher for the system with SOFC as a prime mover.

Development of a Simultaneous Cooling and Heating Absorption Chiller for Combined Heat and Power Systems

2007 ◽  
Author(s):  
Timothy C. Wagner ◽  
Lynn Rog ◽  
Sung-Han Jung
Keyword(s):  
New Jersey ◽  
Power Systems ◽  
Waste Heat ◽  
Combined Heat And Power ◽  
Full Scale ◽  
Energy Utilization ◽  
Simultaneous Operation ◽  
Absorption Chiller ◽  
Additional Energy

The objective of this investigation was the development and testing of a waste heat-driven chiller capable of simultaneously generating chilled and heated water. In addition to simultaneous operation, the ability to seamlessly change from chilling to heating eliminates the seasonal changeover which is typical in existing absorbers. These enhancements significantly increase the flexibility and utilization of the chiller. In this paper, the design of the chiller will be described along with presentation of results from testing of a 140 RT full-scale prototype chiller. A case study for a hospital in New Jersey will also be presented to show the additional energy utilization provided by the simultaneous capability.

scholarly journals Analytical Investigation of a Novel System for Combined Dew Point Cooling and Water Recovery

2021 ◽  
Vol 11 (4) ◽  
pp. 1481
Author(s):  
Aleksandra Cichoń ◽  
William Worek
Keyword(s):  
Energy Consumption ◽  
Convective Heat Transfer Coefficient ◽  
Specific Energy Consumption ◽  
Analytical Investigation ◽  
Dew Point ◽  
Energy Utilization ◽  
Coefficient Of Performance ◽  
Air Cooling ◽  
Water Recovery ◽  
Utilization Factor

This paper presents the analytical investigation of a novel system for combined Dew Point Cooling and Water Recovery (DPC-WR system). The operating principle of the presented system is to utilize the dew point cooling phenomenon implemented in two stages in order to obtain both air cooling and water recovery. The system performance is described by different indicators, including the coefficient of performance (COP), gained output ratio (GOR), energy utilization factor (EUF), specific energy consumption (SEC) and specific daily water production (SDWP). The performance indicators are calculated for various climatic zones using a validated analytical model based on the convective heat transfer coefficient. By utilizing the dew point cooling phenomenon, it is possible to minimize the heat and electric energy consumption from external sources, which results in the COP and GOR values being an order of magnitude higher than for other cooling and water recovery technologies. The EUF value of the DPC-WR system ranges from 0.76 to 0.96, with an average of 0.90. The SEC value ranges from 0.5 to 2.0 kWh/m3 and the SDWP value ranges from 100 to 600 L/day/(kg/s). In addition, the DPC-WR system is modular, i.e., it can be multiplied as needed to achieve the required cooling or water recovery capacity.

Evaluation of Energy Efficiency for a CCHP System With Available Microturbine

2007 ◽  
Author(s):  
H. X. Liang ◽  
Q. W. Wang
Keyword(s):  
Gas Turbine ◽  
Waste Heat ◽  
Energy System ◽  
Primary Energy ◽  
Economic Benefits ◽  
Optimal Operation ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Energetic Efficiency ◽  
Efficiency Evaluation

This paper deals with the problem of energy utilization efficiency evaluation of a microturbine system for Combined Cooling, Heating and Power production (CCHP). The CCHP system integrates power generation, cooling and heating, which is a type of total energy system on the basis of energy cascade utilization principle, and has a large potential of energy saving and economical efficiency. A typical CCHP system has several options to fulfill energy requirements of its application, the electrical energy can be produced by a gas turbine, the heat can be generated by the waste heat of a gas turbine, and the cooling load can be satisfied by an absorption chiller driven by the waste heat of a gas turbine. The energy problem of the CCHP system is so large and complex that the existing engineering cannot provide satisfactory solutions. The decisive values for energetic efficiency evaluation of such systems are the primary energy generation cost. In this paper, in order to reveal internal essence of CCHP, we have analyzed typical CCHP systems and compared them with individual systems. The optimal operation of this system is dependent upon load conditions to be satisfied. The results indicate that CCHP brings 38.7 percent decrease in energy consumption comparing with the individual systems. A CCHP system saves fuel resources and has the assurance of economic benefits. Moreover, two basic CCHP models are presented for determining the optimum energy combination for the CCHP system with 100kW microturbine, and the more practical performances of various units are introduced, then Primary Energy Ratio (PER) and exergy efficiency (α) of various types and sizes systems are analyzed. Through exergy comparison performed for two kinds of CCHP systems, we have identified the essential principle for high performance of the CCHP system, and consequently pointed out the promising features for further development.

Energetic Based Organic Fluid Selection for a Solid Oxide Fuel Cell-Organic Rankine Cycle Combined System

2012 ◽  
Vol 622-623 ◽  
pp. 1162-1167
Author(s):  
Han Fei Tuo
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Heat Recovery ◽  
Waste Heat ◽  
Solid Oxide ◽  
Exhaust Gas ◽  
Oxide Fuel ◽  
Gas Temperature ◽  
Selection For ◽  
Exhaust Gas Temperature

In this study, energetic based fluid selection for a solid oxide fuel cell-organic rankine combined power system is investigated. 9 dry organic fluids with varied critical temperatures are chosen and their corresponding ORC cycle performances are evaluated at different turbine inlet temperatures and exhaust gas temperature (waste heat source) from the upper cycle. It is found that actual ORC cycle efficiency for each fluid strongly depends on the waste heat recovery performance of the heat recovery vapor generator. Exhaust gas temperature determines the optimal fluid which yields the highest efficiency.

scholarly journals Waste heat energy utilization in refrigeration and air-conditioning

2018 ◽  
Vol 402 ◽  
pp. 012060
Author(s):  
Raman Kumar Singh ◽  
Saif Nawaz Ahmad ◽  
Neeraj Priyadarshi ◽  
Md Obaidur Rahman ◽  
A K Bhoi
Keyword(s):  
Air Conditioning ◽  
Waste Heat ◽  
Heat Energy ◽  
Energy Utilization

Optimization of a Novel Combined Power/Refrigeration Thermodynamic Cycle

Solar Energy ◽  
2002 ◽  
Author(s):  
Shaoguang Lu ◽  
D. Yogi Goswami
Keyword(s):  
Waste Heat ◽  
Thermodynamic Cycle ◽  
Cycle Performance ◽  
Working Fluid ◽  
Second Law ◽  
Optimum Conditions ◽  
Ambient Temperatures ◽  
Reduced Gradient ◽  
Generalized Reduced Gradient ◽  
Performance Conditions

A novel combined power/refrigeration thermodynamic cycle is optimized for thermal performance in this paper. The cycle uses ammonia-water binary mixture as a working fluid and can be driven by various heat sources, such as solar, geothermal and low temperature waste heat. It could produce power as well as refrigeration with power output as a primary goal. The optimization program, which is based on the Generalized Reduced Gradient (GRG) algorithm, can be used to optimize for different objective functions. Examples that maximize second law efficiency, work output and refrigeration output are presented, showing the cycle may be optimized for any desired performance parameter. In addition, cycle performance over a range of ambient temperatures was investigated. It was found that for a source temperature of 360K, which is in the range of flat plate solar collectors, both power and refrigeration outputs are achieved under optimum conditions. All performance parameters, including first and second law efficiencies, power and refrigeration output decrease as the ambient temperature goes up. On the other hand, for a source of 440K, optimum conditions do not provide any refrigeration. However, refrigeration can be obtained even for this temperature under non-optimum performance conditions.

scholarly journals Kalina-Flash Cycle Performance Analysis and Parametric Optimization

2019 ◽  
Author(s):  
Raveendra Nath R ◽  
C. Vijaya Bhaskar Reddy ◽  
K.Hemachandra Reddy
Keyword(s):  
Mass Fraction ◽  
Parametric Optimization ◽  
Pressure Ratio ◽  
Cycle Performance ◽  
Second Law ◽  
Water Mixture ◽  
Objective Functions ◽  
Thermodynamic Investigation ◽  
Kalina Cycle ◽  
Multi Objective Genetic Algorithm

In this paper, a thermodynamic investigation is done on a Kalina-flash cycle. This work is initially validated with the Kalina cycle power plant, Wich is commissioned in Husavic. Low-temperature Kalina-flash is considered for this study. This cycle is working with the ammonia-water mixture. The Kalina-flash cycle was optimized in the view of exergy and thermal efficiency. A multi-objective genetic algorithm is used to accomplish optimization. The optimum values of the objective functions are observed to be 40.20 and 11.70% respectively. At last, The influence of the separator inlet dryness fraction, basic ammonia mass fraction, temperature and flash pressure ratio on the first and second law efficiencies are analysed.

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