scholarly journals METHODOLOGY FOR THE UTILIZATION OF WASTE HEAT BY AIR-COOLED COMPRESSORS

2021 ◽  
Vol 2021 (4) ◽  
pp. 4918-4923
Author(s):  
LUKAS PACAS ◽  
Keyword(s):  
Waste Heat ◽  
Cooling System ◽  
Combustion Engine ◽  
Electrical Energy ◽  
External Source ◽  
Compressed Air ◽  
Air Cooling ◽  
Hot Air ◽  
Air Compressors ◽  
Almost All

Compressed air is still a valid helper in many applications today, where it is necessary, for example, to move work equipment, pistons or it is used for cooling as a cooling medium. The producer of compressed air are air compressors, which need an external source for its production, usually an electric or internal combustion engine. Almost all the energy that is supplied to the compressor is always converted to heat during compression, regardless of the type of compressor. This carries the risk of overheating and therefore the cooling system must be optimally designed. Thus, during the compression of the air, a large part of the electrical energy supplied to the compressor is converted into heat, and only a small part of the supplied energy is in the compressed air. In the case of oil or water-cooled compressors, the exchangers can be used directly to obtain energy "for free". In the case of air cooling, a slight energy gain can only be achieved by modifying the exhaust hot air ducts. This energy can be used efficiently to heat water or heat buildings, instead of being uselessly ventilated. Modern compressors are already adapted for the use of waste heat, but most current companies still use older types of compressors that have not been directly adapted for the use of waste heat. In case of interest in obtaining waste heat, the reconstruction of the facility or development is inevitable.

scholarly journals Water-Cooled Thermoelectric Generators for Improved Net Output Power: A Review

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8329
Author(s):  
Björn Pfeiffelmann ◽  
Ali Cemal Benim ◽  
Franz Joos
Keyword(s):  
Output Power ◽  
Waste Heat ◽  
Cooling System ◽  
Electrical Energy ◽  
Air Cooling ◽  
Thermoelectric Generators ◽  
Water Cooling ◽  
Active Cooling ◽  
Microchannel Cooling ◽  
Low Efficiency

Thermoelectric generators (TEGs) have the ability to convert waste heat into electrical energy under unfavorable conditions and are becoming increasingly popular in academia, but have not yet achieved a broad commercial success, due to the still comparably low efficiency. To increase the efficiency and economic viability of TEGs, research is performed on the materials on one hand and on the system connection on the other. In the latter case, the net output power of the cooling system plays a key role. At first glance, passive cooling seems preferable to active cooling because it does not affect the net electrical output power. However, as shown in the present review, the active cooling is to be preferred for net output power. The situation is similar in air and water-cooling. Even though air-cooling is easier to set up, the water-cooling should be preferred to achieve higher net output power. It is shown that microchannel cooling has similar hydraulic performance to conventional cooling and inserts increase the net output power of TEG. As the review reveals that active water-cooling should be the method of choice to achieve high net output power, it also shows that a careful optimization is necessary to exploit the potential.

scholarly journals System Design of Electricity Generation Using Waste Heat from LNG Automobile

2020 ◽  
Vol 145 ◽  
pp. 02062
Author(s):  
Canzong Zhou ◽  
Shuyi Chen ◽  
Wei Cui ◽  
Zhengmao Yao
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Electricity Generation ◽  
Waste Heat ◽  
Cooling System ◽  
Combustion Engine ◽  
Lead Telluride ◽  
Maximum Output ◽  
Thermoelectric Conversion ◽  
Temperature Environment

According to the research, thermoelectricity generation can recycle the heat contained in the cooling system of internal combustion engine. This paper is about taking advantage of the feature in the huge temperature difference at about 560 °C which is formed between high-temperature engine and LNG (Liquefied Natural Gas) in low temperature and the ability that LNG provides semiconductor with thermoelectric conversion material so as to produce the maximum output voltage in low temperature. We take advantage of lead telluride materials that adapt to the high temperature environment and bismuth telluride materials that adapt to the low temperature environment, both of which forms a circuit and are designed as a thermoelectric power generation device. Also, we confirm the possibility of applying the device to cars.

A study on air-cooling waste heat recovery from molten slag of slag-tap boilers

2017 ◽  
Vol 231 (5) ◽  
pp. 371-381
Author(s):  
Lei Deng ◽  
Chunli Tang ◽  
Xiaowen Tan ◽  
Ke Sun ◽  
Song Wu ◽  
...  
Keyword(s):  
Flue Gas ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Molten Slag ◽  
Waste Heat ◽  
Ash Content ◽  
Air Cooling ◽  
Air Preheater ◽  
Hot Air ◽  
Secondary Air

For a better utilization of Zhundong coals which have high fouling and slagging tendency, the slag-tap boiler has attracted much attention. To avoid the high sensible heat loss of discharged molten slag, an air-cooling waste heat recovery system is proposed. Energy and economic analyses are conducted to investigate the effectiveness of heating the desulfurized flue gas by hot air and the influences of partially substituting the secondary air by hot air on heat transfer of air preheater and thermal efficiency of boiler. A case study is performed by referring to a typical 50 MW cyclone boiler with nine types of low fusion temperature coals. The results show that for coals with low ash content, the temperature increment of desulfurized flue gas can be over 7 ℃. While for coals with high ash content, the flue gas temperature can be heated to more than 70 ℃, and the surplus hot air can be sent to the furnace. When the hot air is introduced to partially substitute the secondary air, an instantaneous impact on the air preheater will give rise to a decrement of quantity of heat transferred and increments of temperatures of exit flue gas and hot secondary air. The variations of these thermodynamic parameters become smaller with increasing hot air temperature. After introduction of hot air, the thermal efficiency of boiler can increase, resulting in a decrease of fuel consumption rate. In addition, the heating surface area of air preheater can be reduced.

A Method for Preoptimising the Internal Combustion Engine Air Cooling System

1998 ◽  
Author(s):  
E. Navarro Arévalo ◽  
D. L. Fernández Melcón ◽  
R. Marcos Álvarez ◽  
P. Pérez Illana
Keyword(s):  
Internal Combustion Engine ◽  
Cooling System ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Air Cooling ◽  
Air Cooling System

Performance Assessment of Steam Injection Gas Turbine With Inlet Air Cooling

1997 ◽  
Author(s):  
Carlo M. Bartolini ◽  
Danilo Salvi
Keyword(s):  
Ambient Temperature ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Power Plants ◽  
Waste Heat ◽  
Cooling System ◽  
Steam Injection ◽  
Maximum Efficiency ◽  
Air Cooling

The steam generated through the use of waste heat recovered from a steam injection gas turbine generally exceeds the maximum mass of steam which can be injected into steam injection gas turbine. The ratio between the steam and air flowing into the engine is not more than 10–15%, as an increase in the pressure ratio can cause the compressor to stall. Naturally, the surplus steam can be utilized for a variety of alternative applications. During the warmer months, the ambient temperature increases and results in reduced thermal efficiency and electrical capacity. An inlet air cooling system for the compressor on a steam injection gas turbine would increase the rating and efficiency of power plants which use this type of equipment. In order to improve the performance of steam injection gas turbines, the authors investigated the option of cooling the intake air to the compressor by harnessing the thermal energy not used to produce the maximum quantity of steam that can be injected into the engine. This alternative use of waste energy makes it possible to reach maximum efficiency in terms of waste recovery. This study examined absorption refrigeration technology, which is one of the various systems adopted to increase efficiency and power rating. The system itself consists of a steam injection gas turbine and a heat recovery and absorption unit, while a computer model was utilized to evaluate the off design performance of the system. The input data required for the model were the following: an operating point, the turbine and compressor curves, the heat recovery and chiller specifications. The performance of an Allison 501 KH steam injection gas plant was analyzed by taking into consideration representative ambient temperature and humidity ranges, the optimal location of the chiller in light of all the factors involved, and which of three possible air cooling systems was the most economically suitable. In order to verify the technical feasibility of the hypothetical model, an economic study was performed on the costs for upgrading the existing steam injection gas cogeneration unit. The results indicate that the estimated pay back period for the project would be four years. In light of these findings, there are clear technical advantages to using gas turbine cogeneration with absorption air cooling in terms of investment.

scholarly journals Cuk Converter for Waste Heat Recovery from Automobile Engine using Thermoelectric Generator with Air as Coolant

2020 ◽  
Vol 9 (4) ◽  
pp. 249-252
Keyword(s):  
Energy Efficiency ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Thermoelectric Generator ◽  
Waste Heat ◽  
Combustion Engine ◽  
Electrical Energy ◽  
Internal Combustion ◽  
Heat Energy ◽  
Maximum Power

The growing concern on energy conservation and reduction of carbon footprint has led to a lot of inventions and innovations in terms of energy-efficient technologies in all the energy consuming applications. The automobile sector is a crucial zone where these technologies have a major role to play due to the sheer abundance of the number of automobiles.Many small refinements, alterations and innovations are happening in this field which has led to furthermore energy economic automobiles than before.But even in an advanced internal combustion engine, about two-thirds of fuel consumed by an automobile is discharged into the surroundings as waste heat. The effect of this is the increase in the surrounding air temperature which in turn contributes significantly to global warming. This paper proposes amethod to reduce the emission of heat from automobiles by designing and implementinga waste heat recovery system for internal combustion (IC) engines. The key aim is to reduce the amount of heat released into the environment and to convert it into useful energy. A thermoelectric generator (TEG) assembly is used to directly convert the wasted heat energy from the automobile into electrical energy. This electrical energy is conditioned using a Cukconverter and maximum power point tracking (MPPT) algorithm is embedded in the converter for impedance matching and maximum power transfer from TEG to the converter. The conditioned output is used to charge the battery of the vehicle. This methodologyalso increases the energy efficiency of the vehicle as a higher capacity battery can be employed.The proposed system can work well under varying temperature conditions to give a constant output. It can be implemented in any mechanical/ electrical systems were there is wastage of heat energy like gas pipelines, wearable electronics, space probes, cookstoves, boilers, thermal vision, etc. One of the thrust areas where this technology can be effectively utilized in today’s world is in electric vehicles where the energy efficiency is the most important factor.

scholarly journals Experimental Determination of Dessicant Cooling System for Thermal Comfort

2012 ◽  
pp. 35-37
Author(s):  
Ankit Jain ◽  
Amitesh Paul ◽  
G.L. Selokar
Keyword(s):  
Thermal Comfort ◽  
Experimental Determination ◽  
Cooling System ◽  
Research Work ◽  
Electrical Energy ◽  
Solar Air Heater ◽  
Desiccant Wheel ◽  
Hot Air ◽  
Cooling Technology

Desiccant cooling technology can be used to solve a variety of building comfort, quality and energy related issues. The main objective of my research work was to assess the feasibilities of utilization of solar energy for regeneration of desiccant wheel by hot air provided by solar air heater. It will help in saving electrical energy for regeneration of desiccant wheel.

scholarly journals ВИЗНАЧЕННЯ РАЦІОНАЛЬНОГО ТЕПЛОВОГО НАВАНТАЖЕННЯ ГРАДИРЕНЬ ВІДВЕДЕННЯ ТЕПЛОТИ У ПРОЦЕСАХ КОНДИЦІЮВАННЯ ПОВІТРЯ НА ВХОДІ ЕНЕРГОУСТАНОВОК

2018 ◽  
pp. 19-22
Author(s):  
Андрій Миколайович Радченко ◽  
Євген Іванович Трушляков ◽  
Сергій Анатолійович Кантор ◽  
Богдан Сергійович Портной
Keyword(s):  
Gas Turbine ◽  
Heat Load ◽  
Turbine Unit ◽  
Waste Heat ◽  
Cooling System ◽  
Lithium Bromide ◽  
Air Cooling ◽  
Cooling Towers ◽  
Gas Turbine Unit ◽  
Heat Loads

The air conditioning processes (heat-humidity treatment) at the inlet of energy units by heat-energized refrigeration mechanisms with heat removal cooling towers of the cooling system are studied on the example of a gas turbine unit. Two-stage air cooling is considered applying a two-stage combined type heat-energized refrigeration mechanism, which applies the exhaust gas heat of a gas turbine unit and which includes absorption lithium-bromide and refrigerant ejector refrigeration mechanism as steps to convert waste heat into cold. Based on the results of modeling the operation of the cooling complex of a gas turbine unit, data was obtained on current heat loads on heat-energized refrigeration mechanisms and cooling towers in accordance with the climatic conditions of operation with different distribution of project heat loads on the air cooling stages and, accordingly, on the transformation of waste heat into cold. Due to the fact that the heat load on the cooling towers depends on the efficiency of transformation of waste heat into cold (heat coefficients) by absorption lithium-bromide and refrigerant ejector refrigeration mechanisms, a rational distribution of the project heat loads to the absorption and ejector stages of a combined type heat-energized refrigeration mechanisms that provides reduce heat load on cooling towers. It is demonstrated that due to this approach to determining the rational heat load on the cooling towers of the cooling system, which consists of calculation the redistribution of heat load between the  absorption lithium-bromide and refrigerant ejector cooling stages with different efficiency and transformation of waste heat (different heat coefficients) in accordance with current climate conditions, is possible to minimize the number of cooling with a corresponding reduction in capital expenditures on the air conditioning system at the inlet of gas turbine unit

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