scholarly journals Conversion of gas engine waste heat into cold using absorption chillers

2020 ◽  
Vol 168 ◽  
pp. 00046
Author(s):  
Georgii Karman ◽  
Yurii Oksen ◽  
Olena Trofymova ◽  
Yurii Komissarov ◽  
Borys Dizhevskyi ◽  
...  
Keyword(s):  
Air Conditioning ◽  
Waste Heat ◽  
Lithium Bromide ◽  
Thermodynamic Cycle ◽  
Cooling Capacity ◽  
Coolant Temperature ◽  
Gas Engine ◽  
Absorption Chillers ◽  
Full Conversion ◽  
Heating Medium

A possibility of gas engine waste heat conversion into cold for air conditioning in mines using lithium bromide absorption chillers is investigated. Dependencies of parameters of a thermodynamic cycle and energy indicators of chillers on temperatures of a heating medium and a coolant are obtained using mathematical modelling. It is shown that it is rational to use two chillers with sequential movement of a heating medium and a coolant through them in opposite directions for a full conversion of gas engine waste heat. COP of such a system is 0.733. This allows obtaining 2140 kW of cooling capacity with a coolant temperature of 7 °C when using a gas engine JMS-620 by Jenbacher.

Performance Evaluation of a 4.5 kW (1.3 Refrigeration Tons) Air-Cooled Lithium Bromide/Water Hot-Water-Fired Absorption Unit

2007 ◽  
Author(s):  
Abdolreza Zaltash ◽  
Andrei Petrov ◽  
Randall Linkous ◽  
Edward Vineyard ◽  
David Goodnack ◽  
...  
Keyword(s):  
Heat Exchangers ◽  
Air Conditioning ◽  
Cooling Tower ◽  
Lithium Bromide ◽  
Cooling Capacity ◽  
Hot Water ◽  
Next Generation ◽  
Absorption Chiller ◽  
Flow Rates ◽  
Absorption Chillers

During the summer months, air-conditioning (cooling) is the single largest use of electricity in both residential and commercial buildings with the major impact on peak electric demand. Improved air-conditioning technology has by far the greatest potential impact on the electric industry compared to any other technology that uses electricity. Thermally activated absorption air-conditioning (absorption chillers) can provide overall peak load reduction and electric grid relief for summer peak demand. This paper describes an innovative absorption technology based on integrated rotating heat exchangers to enhance heat and mass transfer resulting in a potential reduction of size, cost, and weight of the “next generation” absorption units. This absorption chiller (RAC) is a 4.5 kW (1.3 refrigeration tons or RT) air-cooled lithium bromide (LiBr)/water unit powered by hot water generated using the solar energy and/or waste heat. Typically LiBr/water absorption chillers are water-cooled units which use a cooling tower to reject heat. Cooling towers require a large amount of space and increase start-up and maintenance costs. However, RAC is an air-cooled absorption chiller which requires no cooling tower. The purpose of this evaluation is to verify RAC performance by comparing the Coefficient of Performance (COP or ratio of cooling capacity to thermal energy input) and the cooling capacity results with those of the manufacturer. The performance of the RAC was tested at Oak Ridge National Laboratory (ORNL) in a controlled environment at various hot and chilled water flow rates, air handler flow rates, and ambient temperatures. Temperature probes, mass flow meters, rotational speed measuring device, pressure transducers, and a web camera mounted inside the unit were used to monitor the RAC via a web control-based data acquisition system using Automated Logic Controller (ALC). Results showed a COP and cooling capacity of approximately 0.58 and 3.7 kW respectively at 35°C (95°F) design condition for ambient temperature with 40°C (104°F) cooling water temperature. This is in close agreement with the manufacturer data of 0.60 for COP and 3.9 kW for cooling capacity. Future work will use these performance results to evaluate the potential benefits of rotating heat exchangers in making the “next-generation” absorption chillers more compact and cost effective without any significant degradation in the performance. Future studies will also evaluate the feasibility of using rotating heat exchangers in other applications.

scholarly journals Calculation of marine air conditioning systems based on energy savings

2017 ◽  
Vol 11 (21) ◽  
pp. 103
Author(s):  
Ricardo A. Lugo-Villalba ◽  
Mario Álvarez Guerra ◽  
Bienvenido Sarria López
Keyword(s):  
Air Conditioning ◽  
Energy Savings ◽  
Waste Heat ◽  
Cooling Capacity ◽  
Efficient Operation ◽  
Average Value ◽  
Economic Operation ◽  
International Policies ◽  
Need To Evaluate ◽  
Air Conditioning Systems

The development of ship propulsion in the areas of Economic Operation, Environmental Protection and Ship Efficiency (Triple E - Economy, Environment, Efficiency) is the comparison standard of the manufacturers of contemporary ships. The standard is based on the application of a more modern design of the diesel engines, the wide use of waste heat and the efficient operation of the ship.In accordance with the Economic Operation, the need to evaluate the design of air conditioning systems has been identified in order to determine the possible savings, which are represented by a decrease in fuel consumption, as a result of: the significant impact of this consumption in the operation of the ship, the current high costs of this energy, the periodic increase in the price of the same, and the international policies for the reduction of emissions to the atmosphere and preservation of the environment.By means of the energy diagnosis of the air conditioning system it is possible to determine the possible opportunities of energy saving during the operation of the ship.The results indicate that the thermal load and the cooling capacity required by the air conditioned spaces have a difference between their maximum and average value of 14%. This justifies the need to use a conditioning system with a variable volume of air supplied to the air conditioned space.

Simulation Analysis of Primary Energy Ratio for Air-Source Gas Engine-Driven Heat Pump

2014 ◽  
Vol 953-954 ◽  
pp. 692-697
Author(s):  
Xiao Feng Ren ◽  
Shu Xing Zhao ◽  
Zhi Chao Wang ◽  
Yi Tao Zhou ◽  
Ying Jie Zhang
Keyword(s):  
Heat Pump ◽  
Air Conditioning ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Simulation Analysis ◽  
Waste Heat ◽  
Primary Energy ◽  
Energy Ratio ◽  
Gas Engine ◽  
Gas Consumption

Based on the simulation of the air conditioning construction dynamic load and simulation calculation of air-source gas engine-driven heat pump (GEHP), the air-source GEHP air conditioning in winter, summer and the annual primary energy ratio are analyzed in simulation with the combination of a hotel building in Tianjin. Firstly, DeST software is used to simulate all-year hourly air conditioning load of the building. Then air-source GEHP simulation model [1] is used to calculate the annual hourly gas consumption and the amount of GEHP's gas consumption in winter, summer and a total year afterwards can be got. At the same time, by the analysis of waste heat recovery of gas engine-driven, primary energy ratio for air-source GEHP in Tianjin is given under the different waste heat recovery of winter, summer and the annual.

Utilization of Low Temperature Waste Heat for Cold TES

2002 ◽  
Author(s):  
James J. Rizza
Keyword(s):  
Low Temperature ◽  
Air Conditioning ◽  
Waste Heat ◽  
Water Solution ◽  
Lithium Bromide ◽  
Thermal Storage ◽  
Energy System ◽  
Storage Material ◽  
Ideal System ◽  
Temporal Variance

This paper presents an advanced energy cogeneration system that utilizes low temperature waste heat in the range of 60°C to 95°C to produce cold thermal energy storage (TES). Since there is usually a temporal variance between the availability of low temperature waste heat and demand for commercial building air conditioning, a cold TES system is incorporated into this advance energy system. The proposed TES system uses a lithium bromide/water solution both as a refrigerant and as a cold thermal storage material. The cold storage material can be stored at ambient temperature without thermal insulation for an indefinite period of time without losing its charge, making it an ideal system for utilizing peaking system’s low temperature waste heat or to utilize low temperature waste heat during nocturnal operation of continuous generation systems at a time when there are usually low or minimal air conditioning requirements. The heat pump and waste heat is used to recover the thermal storage by reprocessing the stored lithium bromide weak solution to a higher concentration.

scholarly journals An overview on use of desiccant dehumidifiers in modern air-conditioning

2019 ◽  
pp. 16-31
Author(s):  
Jani DB
Keyword(s):  
Solar Energy ◽  
Air Conditioning ◽  
Heat Recovery ◽  
Waste Heat ◽  
Cooling System ◽  
Electrical Energy ◽  
Cooling Capacity ◽  
Primary Energy ◽  
Hybrid Cooling ◽  
Hot And Humid Climates

The solid desiccant based dehumidifier used in conjunction with the conventional HVAC combines the dehumidification of solid desiccant system and with the cooling capacity of the conventional air conditioning system. This hybrid cooling system provides thermal comfort to the occupants of the conditioned space. The hybrid systems main appeal lies in the fact that, it consumes much lesser high grade electrical energy as compared to the dedicated standalone traditional air conditioning systems. The electrical energy usage is possible still lower by use of primary energy sources for to supply the thermal energy needed for the desiccant regeneration. For this purpose freely available renewable solar energy or industrial waste heat can also be used for the regeneration heat source. Sometimes it is also possible to provide condenser waste heat for the part of desiccant reactivation heat supply may increase the overall performance of the system. It was also found that this cooling system with use of air to air waste heat recovery wheel performed better than without it in terms of dehumidification as well as cooling performance. The present study report important literature survey on the dehumidification potentials of desiccant integrated hybrid cooling system operating in hot and humid climates. Keywords: Hybrid air-conditioning; Rotary desiccant dehumidifier; Heat recovery wheel; Regeneration heat; Renewable solar energy; Waste heat

Analysis of Heat Pipe Heat Exchanger (HPHE) For Waste Heat Recovery from an Air Conditioning System

2007 ◽  
Vol 2 (3) ◽  
pp. 86-95
Author(s):  
R. Sudhakaran ◽  
◽  
V. Sella Durai ◽  
T. Kannan ◽  
P.S. Sivasakthievel ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Heat Pipe ◽  
Air Conditioning ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Air Conditioning System ◽  
Pipe Heat

scholarly journals Evaporative Cooling Options for Building Air-Conditioning: A Comprehensive Study for Climatic Conditions of Multan (Pakistan)

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3061 ◽  
Author(s):  
Shazia Noor ◽  
Hadeed Ashraf ◽  
Muhammad Sultan ◽  
Zahid Mahmood Khan
Keyword(s):  
Thermal Comfort ◽  
Co2 Emissions ◽  
Air Conditioning ◽  
Evaporative Cooling ◽  
Cooling Capacity ◽  
Climatic Conditions ◽  
Maximum Temperature ◽  
Human Thermal Comfort ◽  
Work Input ◽  
System Configurations

This study provides comprehensive details of evaporative cooling options for building air-conditioning (AC) in Multan (Pakistan). Standalone evaporative cooling and standalone vapor compression AC (VCAC) systems are commonly used in Pakistan. Therefore, seven AC system configurations comprising of direct evaporative cooling (DEC), indirect evaporative cooling (IEC), VCAC, and their possible combinations, are explored for the climatic conditions of Multan. The study aims to explore the optimum AC system configuration for the building AC from the viewpoints of cooling capacity, system performance, energy consumption, and CO2 emissions. A simulation model was designed in DesignBuilder and simulated using EnergyPlus in order to optimize the applicability of the proposed systems. The standalone VCAC and hybrid IEC-VCAC & IEC-DEC-VCAC system configurations could achieve the desired human thermal comfort. The standalone DEC resulted in a maximum COP of 4.5, whereas, it was 2.1 in case of the hybrid IEC-DEC-VCAC system. The hybrid IEC-DEC-VCAC system achieved maximum temperature gradient (21 °C) and relatively less CO2 emissions as compared to standalone VCAC. In addition, it provided maximum cooling capacity (184 kW for work input of 100 kW), which is 85% higher than the standalone DEC system. Furthermore, it achieved neutral to slightly cool human thermal comfort i.e., 0 to −1 predicted mean vote and 30% of predicted percentage dissatisfied. Thus, the study concludes the hybrid IEC-DEC-VCAC as an optimum configuration for building AC in Multan.

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