Liquid-Coupled Indirect-Transfer Exchanger Application to the Diesel Engine

1979 ◽  
Vol 101 (4) ◽  
pp. 516-523 ◽  
Author(s):  
James C. Eastwood
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Cooling System ◽  
Relative Effectiveness ◽  
Ambient Air ◽  
Air Cooling ◽  
Performance Curves ◽  
Air Cooling System ◽  
Cooling Function ◽  
Low Charge

The efficiency of turbocharged diesel engines can be increased by cooling the charge air. This paper presents a design approach for liquid-coupled indirect-transfer heat exchanger systems to perform the air-cooling function. The two advantages most commonly cited for this approach to charge-air cooling are (1) the heat exchangers involved are easily packaged so that their shapes can be controlled by judicious design, and (2) simple gas ducting allows for compact machinery arrangements and relatively low charge-air pressure drop. An analytical approach to the design of liquid-coupled indirect-transfer heat exchanger systems is presented. Performance curves are constructed on the basis of this analysis. Four important design conditions are evident from the observation of these performance curves including (1) the relative capacity rate combination of the three fluids (ambient air, coupling liquid, and engine charge-air) which yields the highest overall effectiveness, (2) an optimum coupling-liquid flow rate, (3) the relative effectiveness distribution for each of the two component heat exchangers (hot and cold components), and (4) a broad design range for the optimum area distribution between the hot and cold exchangers. These performance curves serve as a guide for the design of a liquid-coupled charge-air cooling system.

Enhancing the Performance of the Building’s Vapor Compression Air Cooling System Using Earth-Air Heat Exchanger

2017 ◽  
Author(s):  
Fadi A. Ghaith ◽  
Fadi J. Alsouda
Keyword(s):  
Heat Exchanger ◽  
Soil Temperature ◽  
Air Temperature ◽  
Cooling System ◽  
Ambient Air ◽  
Coefficient Of Performance ◽  
Maximum Deviation ◽  
Air Cooling ◽  
Vapor Compression ◽  
Air Cooling System

This paper aims to evaluate the thermal performance and feasibility of integrating the Earth-Air Heat Exchanger (EAHE) with the building’s vapor compression air cooling system. In the proposed system, the ambient air is forced by an axial fan through an EAHE buried at a certain depth below the ground surface. EAHE uses the subsoil low temperature and soil thermal properties to reduce the air temperature. The outlet air from the EAHE was used for the purpose of cooling the condenser of the vapor compression cycle (VCC) to enhance its coefficient of performance (COP). The potential enhancement on the COP was investigated for two different refrigerants (i.e. R-22 and R410a) cooling systems. A mathematical model was developed to estimate the underground soil temperature at different depths and the corresponding outlet air temperature of EAHE was calculated. The obtained results showed that the soil temperature in Dubai at 4 meters depth is about 27°C and remains relatively constant across the year. In order to estimate the effect of using EAHE on the performance of the VCC system, a sample villa project was selected as a case study. The obtained results showed that EAHE system contributed efficiently to the COP of the VCC with an overall increase of 47 % and 49 % for R-22 and R410a cycles, respectively. Moreover, the calculated values were validated against Cycle_D simulation model and showed good agreement with a maximum deviation of 5%. The payback period for this project was found to be around two years while the expected life time is about 10 years which makes it an attractive investment.

scholarly journals Innovative Turbine Intake Air Cooling Systems and Their Rational Designing

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6201
Author(s):  
Andrii Radchenko ◽  
Eugeniy Trushliakov ◽  
Krzysztof Kosowski ◽  
Dariusz Mikielewicz ◽  
Mykola Radchenko
Keyword(s):  
Gas Turbines ◽  
Maximum Rate ◽  
Cooling System ◽  
Ambient Air ◽  
Cooling Capacity ◽  
Climatic Conditions ◽  
Air Cooling ◽  
Thermal Loads ◽  
Cooling Systems ◽  
Air Cooling System

The efficiency of cooling ambient air at the inlet of gas turbines in temperate climatic conditions was analyzed and reserves for its enhancing through deep cooling were revealed. A method of logical analysis of the actual operation efficiency of turbine intake air cooling systems in real varying environment, supplemented by the simplest numerical simulation was used to synthesize new solutions. As a result, a novel trend in engine intake air cooling to 7 or 10 °C in temperate climatic conditions by two-stage cooling in chillers of combined type, providing an annual fuel saving of practically 50%, surpasses its value gained due to traditional air cooling to about 15 °C in absorption lithium-bromide chiller of a simple cycle, and is proposed. On analyzing the actual efficiency of turbine intake air cooling system, the current changes in thermal loads on the system in response to varying ambient air parameters were taken into account and annual fuel reduction was considered to be a primary criterion, as an example. The improved methodology of the engine intake air cooling system designing based on the annual effect due to cooling was developed. It involves determining the optimal value of cooling capacity, providing the minimum system sizes at maximum rate of annual effect increment, and its rational value, providing a close to maximum annual effect without system oversizing at the second maximum rate of annual effect increment within the range beyond the first maximum rate. The rational value of design cooling capacity provides practically the maximum annual fuel saving but with the sizes of cooling systems reduced by 15 to 20% due to the correspondingly reduced design cooling capacity of the systems as compared with their values defined by traditional designing focused to cover current peaked short-term thermal loads. The optimal value of cooling capacity providing the minimum sizes of cooling system is very reasonable for applying the energy saving technologies, for instance, based on the thermal storage with accumulating excessive (not consumed) cooling capacities at lowered current thermal loads to cover the peak loads. The application of developed methodology enables revealing the thermal potential for enhancing the efficiency of any combustion engine (gas turbines and engines, internal combustion engines, etc.).

Analysis of Intercooler in PEM Fuel Cell Systems

Volume 3 ◽  
2004 ◽  
Author(s):  
Takamasa Ito ◽  
Jinliang Yuan ◽  
Bengt Sunde´n
Keyword(s):  
Heat Exchanger ◽  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Cooling System ◽  
Ambient Air ◽  
Proton Exchange ◽  
High Mass ◽  
Air Cooling ◽  
Cell Systems ◽  
Cold Stream

Heat exchangers are used in proton exchange membrane fuel cell systems (PEMFCs) for stack cooling, intercooling, water condensation and fuel reforming. Especially, the heat exchanger for the intercooling before the humidifier is investigated in this paper. It is found that, at high pressure or high mass flow rate, the need to cool the air (oxidant) is large. The heat exchanger uses coolant water from the stack cooling system or ambient air as the cold stream. With water-cooling, the volume of the heat exchanger will be small. However, difficulties exist because the small available temperature difference. Air-cooling can be used over a wide operating range but the heat exchanger volume will be large.

scholarly journals ОЦІНКА ЕФЕКТИВНОСТІ ГЛИБОКОГО ОХОЛОДЖЕННЯ ПОВІТРЯ НА ВХОДІ ГТУ ТЕПЛОВИКОРИСТОВУЮЧИМИ ХОЛОДИЛЬНИМИ МАШИНАМИ

2019 ◽  
pp. 10-14
Author(s):  
Андрій Миколайович Радченко ◽  
Богдан Сергійович Портной ◽  
Сергій Анатолійович Кантор ◽  
Ігор Петрович Єсін
Keyword(s):  
Gas Turbine ◽  
Heat Load ◽  
Turbine Unit ◽  
Waste Heat ◽  
Cooling System ◽  
Mechanical Energy ◽  
Ambient Air ◽  
Air Cooling ◽  
Gas Turbine Unit ◽  
Air Cooling System

Significant fluctuations in the current temperature and relative humidity of the ambient air lead to significant changes in the heat load on the air cooling system at the inlet of the gas turbine unit, which urgently poses the problem of choosing their design heat load, as well as evaluating the efficiency of the air cooling system for a certain period of time. The efficiency of deep air cooling at the inlet of gas turbine units was studied with a change during July 2015–2018 for climatic conditions of operation at the compressor station Krasnopolie, Dnepropetrovsk region (Ukraine). For air cooling, the use of a waste heat recovery chiller, which transforms the heat of exhaust gases of gas turbine units into the cold, has been proposed. The efficiency of air cooling at the inlet of gas turbine units for different temperatures has been analyzed: down to 15 °C – an absorption lithium-bromide chiller, which is used as the first high-temperature stage for pre-cooling of ambient air, and down to 10 °C – a combined absorption-ejector chiller (with using a refrigerant low-temperature air cooler as the second stage of air cooling). The effect of air-cooling was assessed by comparing the increase in the production of mechanical energy as a result of an increase in the power of a gas turbine unit and fuel saved during the month of July for 2015-2018 in accumulating. Deeper air cooling at the inlet of the gas turbine unit to a temperature of 10 °C in a combined absorption-ejector chiller compared to its traditional cooling to 15 °C in an absorption bromine-lithium chiller provides a greater increase in net power and fuel saved. It is shown that due to a slight discrepancy between the results obtained for 2015-2018, a preliminary assessment of the efficiency of air cooling at the inlet of gas turbine plants can be carried out for one year.

Experimental Investigation of a Combined Photovoltaic Thermal System via Air Cooling for Summer Weather of Egypt

2020 ◽  
Vol 12 (4) ◽  
Author(s):  
Hussein M. Maghrabie ◽  
A. S. A. Mohamed ◽  
M. Salem Ahmed
Keyword(s):  
Cooling System ◽  
Electrical Power ◽  
Ambient Air ◽  
Critical Issue ◽  
Air Cooling ◽  
Pv Panel ◽  
Current Implementation ◽  
Air Cooling System ◽  
Forced Air ◽  
Electrical Power Output

Abstract Utilizing photovoltaic (PV) panels for generating electrical power is accompanied with a low electrical efficiency that is further reduced as its surface temperature surpasses an acceptable limit. In order to overcome this critical issue, it is necessary to maintain the PV panels relatively at low surface temperatures as possible as using appropriate cooling systems. The current implementation assesses experimentally the performance of a combined PV thermal (PV/T) system using a forced-air cooling system during April, May, June, and July of summer weather of Egypt. The results reveal that the highest values of the solar intensity and the ambient air temperature are obtained in July. Employing the forced-air cooling system reduces the average temperature on the front and back sides of the PV panel during July by 12% and 12.8%, respectively. In addition, the forced-air cooling system enhances noticeably the electrical power output of the PV panel by 3.3%, 4.3%, 4.5%, and 6.1% during April, May, June, and July, respectively. Moreover, the maximum value of the average thermal efficiency achieved during July is 37%; whereas, the corresponding value of the average overall efficiency fulfilled during April is 48.7%.

Economic Evaluation on GTCC Inlet Air Cooling With Absorption Chiller

2005 ◽  
Author(s):  
Cheng Yang ◽  
Zeliang Yang ◽  
Ruixian Cai
Keyword(s):  
Economic Evaluation ◽  
Fuel Consumption ◽  
Output Power ◽  
Air Temperature ◽  
Cooling System ◽  
Ambient Air ◽  
Air Cooling ◽  
Absorption Chiller ◽  
Air Cooling System ◽  
Temperature Depression

Inlet air temperature increase results in a considerable reduction in GTCC power output. Present design of inlet air cooling system usually applied static method, which considered a constant depression of inlet air temperature, an approximate estimate of runtime, output power increase and fuel consumption variation per temperature depression, etc. However, to a crumb, at least another two problems should be studied. One is GTCC performance variation with inlet air temperature, since the kilowatt increment per centigrade is not a constant; the other is off design performance of inlet air cooling system, since the inlet air temperature depression through the cooling system varies with the actual operation conditions, such as ambient air temperature and cooling water temperature, etc. This paper presents an economic evaluation with numerical integration method on GTCC inlet air cooling with absorption chiller. For a typical GTCC composed of series E gas turbine and combined components, their non-dimensional performance curves are fitted with regression equations. Associating with these equations, the inlet air temperature characteristics of GTCC are simulated; and the fitted analytical expressions for GTCC inlet air temperature characteristics are also presented. The simulation method of off design performance of a typical absorption chiller is described. For a typical GTCC with inlet air cooling in south China area, integrated with the everyday typical weather data, GTCC everyday average output power and fuel consumption, output power increment and GTCC fuel consumption increment are simulated. The simulation results show that, for every 1°C depression in inlet air temperature, the GTCC output power increases 0.5%, while heat rate varies slightly and trends towards a rise at the inlet air temperature of about 15°C. Research on inlet air cooling scheme (Scheme 10°C, cooling the ambient air temperature from ambient temperature 30°C to 10°C) shows that, Scheme 10°C yields annual average 16°C of inlet air temperature depression. Economic evaluation based on numerical integration indicates that, in the case of Scheme 10°C, annual output power increases by 8.27%, fuel consumption rate increases by 1.03%; payback period approximately amounts to 2.0 years when power price is 12 cent/(kW.h) and fuel cost is $265/t.

Applications of Gas Turbine Plants With Cooled Compressor Intake Air

2001 ◽  
Author(s):  
E. Kakaras ◽  
A. Doukelis ◽  
J. Scharfe
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Cooling System ◽  
Ambient Air ◽  
Climatic Conditions ◽  
Air Cooling ◽  
Iso Standard ◽  
Air Temperatures ◽  
Air Cooling System ◽  
Alternative Scenarios

The operation of gas turbines at ambient air temperatures higher than the ISO standard conditions (15°C) causes performance penalties both in the generated power and the efficiency of the engine. At high inlet-air temperatures, there can be a power loss of more than 20% combined with a significant increase in specific fuel consumption, compared to the ISO standard conditions. Thus, over a long period of time, gas turbines have a lower power output and efficiency than the equipment could actually perform. It is the purpose of this work to present the possibilities and advantages from the integration of an innovative air-cooling system for reducing the gas turbine intake-air temperature. The advantages of this system are demonstrated by examining alternative scenarios of usage, representative of different countries and different climatic conditions.

scholarly journals Increasing electrical power output and fuel efficiency of gas engines in integrated energy system by absorption chiller scavenge air cooling on the base of monitoring data treatment

2018 ◽  
Vol 70 ◽  
pp. 03011 ◽  
Author(s):  
Andrii Radchenko ◽  
Mykola Radchenko ◽  
Andrii Konovalov ◽  
Anatolii Zubarev
Keyword(s):  
Power Output ◽  
Cooling System ◽  
Ambient Air ◽  
Energy System ◽  
Air Cooling ◽  
Absorption Chiller ◽  
Gas Engine ◽  
Air Temperatures ◽  
Air Cooling System ◽  
Integrated Energy System

An advanced scavenge air cooling system for reciprocating gas engines of integrated energy system for combined electricity, heat and refrigeration generation has been developed. New method of deep scavenge air cooling and stabilizing its temperature at increased ambient air temperatures and three-circuit scavenge air cooling system with absorption lithium-bromide chiller and wet-type cooling tower was proposed. Such cooling method does not require essential constructive changes in the existing scavenge air cooling system but only an addition heat exchanger for chilling scavenge air cooling water of scavenge air low-temperature intercooler closed contour by absorption chiller. A chilled water from absorption chiller is used as a coolant. To evaluate the effect of gas engine scavenge air deeper cooling compared with its typical radiator cooling, data on the dependence of fuel consumption and power output of gas engine on ambient air temperature at the inlet of the radiator are analized. The efficiency of engine scavenge air deep cooling at increased ambient air temperatures was estimated by reducing the gas fuel consumption compared with radiator cooling.

Dynamic Analysis of Hybrid Cooling Data Centers Subjects to the Failure of CRAC Units

2013 ◽  
Author(s):  
Tianyi Gao ◽  
Emad Samadiani ◽  
Roger Schmidt ◽  
Bahgat Sammakia
Keyword(s):  
Data Center ◽  
Heat Exchangers ◽  
Data Centers ◽  
Cooling System ◽  
Normal Operation ◽  
Air Cooling ◽  
Rear Door ◽  
Hybrid Cooling ◽  
Air Cooling System ◽  
The Impact

Thermal management of high power data centers poses challenges due to the high operational cost which is made worse due to the many inefficiencies that arise in them. Additional challenges arise due to the dynamic behaviors that occur during normal operation, and also during emergencies such as power outages or failure of some or all of the cooling equipment. Water and hybrid air plus water cooled data centers are an alternate cooling solution combining liquid cooling systems, such as rear door heat exchangers located within the racks themselves, in addition to the traditional raised floor cold aisle air cooling system. Such a solution may be used when some of the equipment in a data center is upgraded to higher end and higher power equipment which may not be manageable with the existing air cooling system. For a data center with a hybrid cooling system, the cold air supply and the cold water supply should increase in case of an emergency, such as a CRAC (Computer Room Air Conditioner) units’ failure. In this paper, a detailed computational study is conducted to investigate the dynamic response of the impact of a CRAC failure on both water side and air side in a representative hybrid cooling room. The room studied is an air cooled data center using the common cold aisle approach, with rear door heat exchangers installed on all of the racks. CRAC failure is investigated in a hybrid cooling room. The variation and fluctuation in an average rack inlet temperature, and inlet temperatures at different detail locations are presented in plots, showing the dynamic performance of a hybrid cooling data center subjected to the different CRAC failure scenarios. Different response time studies are also presented in this paper.

Measurement and Control of the Gas Turbine Inlet Air Cooling System

2012 ◽  
Vol 220-223 ◽  
pp. 439-442
Author(s):  
Jian Wang ◽  
Jiang Zhou Shu ◽  
Guo Hui Huang ◽  
Ai Peng Jiang
Keyword(s):  
Waste Heat ◽  
Cooling System ◽  
Lithium Bromide ◽  
Ambient Air ◽  
Low Pressure ◽  
Air Cooling ◽  
Waste Heat Boiler ◽  
Air Cooling System ◽  
And Control ◽  
Measurement And Control

As a constant-column power generating machine, the combustion turbine has a direct proportion of its output to the quantity of input air. Therefore, when the ambient air temperature rises higher in summer, the effect of combustion turbine is decreasing. In order to enhance the efficiency of combustion turbine in summer, two sets of inlet air cooling system (IACS) were installed in PG6551(B) combustion turbines in Jinhua, Zhejiang, China. Two low-pressure evaporators were installed in the caudal flue of the waste heat boiler, therefore, the produced saturation steam drives a single-effect lithium bromide absorption chiller to cool the input air of combustion turbines to raise the output power of combustion turbine in summer; or supplies the low-pressure heater to heat the condensated water from the deaerator of the steam turbine in winter. A measurement and control system (MCS) of the new-added inlet air cooling equipments was developed. Based on the framework of DCS (Distributed Computer System), the M&C system has the IACS work correctly and easily. The structure and functions of the M&C is described in detail.

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