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

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.).

2019 ◽  
pp. 56-60
Author(s):  
Андрій Миколайович Радченко ◽  
Ян Зонмін ◽  
Микола Іванович Радченко ◽  
Сергій Анатолійович Кантор ◽  
Богдан Сергійович Портной ◽  
...  

Significant fluctuations of the current temperature and relative humidity of the ambient air lead to significant changes in the thermal load on the cooling system at the inlet of gas turbine units (GTU), which acutely raises the problem of choosing their installed (design) thermal load. Calculations of ambient air cooling processes were carried out for different climatic conditions, for example, southern Ukraine (Mykolaiv) and Central China (Beijing). It is  analyzed two methods of determination of the installed (design) cooling capacity of the ambient air cooling system at the GTU inlet according to the maximum current reduction of fuel consumption and according to the maximum rate (increase) of annual reduction of fuel consumption following to increasing of the installed cooling capacity, calculated by summarizing the current values of fuel consumption reduction. It is shown that the values of the installed cooling capacity of the air cooling system at the GTU inlet, determined by both methods, are close enough but differ significantly for different climatic conditions. The advantage of the method of calculating the installed cooling capacity of the air cooling system at the GTU inlet according to the maximum rate of annual reduction in fuel consumption is the possibility of a more precise definition of it due to the absence of significant fluctuations in the annual reduction in fuel consumption, calculated by summarizing the current values of fuel consumption reduction. Since the maximum reduction in fuel consumption per year is achieved with some decrease in the rate of its increment at high values of the design cooling capacity, required in the hottest hours in the summer and excessive in somewhat cool periods (at night and in the morning even in the summer), the installed cooling capacity, determined according to the maximum rate of the reduction of fuel consumption, will be insufficient in times of increased thermal loads above their design value. In such cases, the elimination of the deficit in cooling capacity is possible by using an excess of cold accumulated during reduced thermal loads


Author(s):  
E. Kakaras ◽  
A. Doukelis ◽  
J. Scharfe

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.


2018 ◽  
Vol 70 ◽  
pp. 03012 ◽  
Author(s):  
Roman Radchenko ◽  
Andrii Radchenko ◽  
Serhiy Serbin ◽  
Serhiy Kantor ◽  
Bohdan Portnoi

Two-stage Gas turbine unite (GTU) inlet air cooling by absorption lithium-bromide chiller (ACh) to the temperature 15 °C and by refrigerant ejector chiller (ECh) to 10 °C through utilizing the turbine exhaust gas heat for changeable ambient air temperatures and corresponding heat loads on the air coolers for the south Ukraine climatic conditions is analysed. An excessive refrigeration capacity of combined absorption-ejector chiller (AECh) exceeding the current heat loads and generated at decreased heat loads on the air coolers at the inlet of GTU can be used for covering increased heat loads to reduce the refrigeration capacity of AECh. The GTU inlet air cooling system with an ambient air precooling booster stage and a base two-stage cooling air to the temperature 10 °C by AECh is proposed. The AECh excessive cooling capacity generated during decreased heat loads on the GTU inlet air coolers is conserved in the thermal accumulator and used for GTU inlet air precooling in a booster stage of air cooler during increased heat loads. There is AECh cooling capacity reduction by 50% due to the use of a booster stage for precooling GTU inlet ambient air at the expense of an excessive cooling capacity accumulated in the thermal storage.


Author(s):  
Sandu Constantin ◽  
Dan Brasoveanu

Thermal efficiency of gas turbines is critically dependent on temperature of burnt gases at turbine inlet, the higher this temperature the higher the efficiency. Stochiometric combustion would provide maximum efficiency, but in the absence of an internal cooling system, turbine blades cannot tolerate gas temperatures exceeding 1300 K. This temperature yields a low thermal efficiency, about 15% below the level provide by stoicthiometric combustion. Conventional engines rely on air for blade and disk cooling and limit temperature at turbine inlet to about 1500 K. These engines gain about 3% compared to non-cooled designs. Gas turbines with state of the art air-cooling systems reach up to 1700–1750 K, boosting thermal efficiency by another 2–3%. These temperatures are near the limit allowed by air-cooling systems. Cooling systems with air are easier to design, but air has a low heat transfer capacity, and compressor air bleeding lowers the overall efficiency of engines (less air remains available for combustion). In addition, these systems waste most of the heat extracted from turbine for cooling. In principle, gas turbines could be cooled with liquid. Half a century ago, designers tried to place the pump for coolant recirculation on the engine stator. Liquid was allowed to boil inside the turbine. Seals for parts in relative motion cannot prevent loss of superheated vapors, therefore these experiments failed. To circumvent this problem, another design relied on thermal gradients to promote recirculation from blade tip to root. Liquid flow and cooling capacity were minute. Therefore it was assumed that liquid couldn’t be used for gas turbine cooling. This is an unwarranted assumption. The relative motion between engine stator and rotor provides abundant power for pumps placed on the rotor. The heat exchanger needed for cooling the liquid with ambient air could also be embedded in the rotor. In fact, the entire cooling system can be encapsulated within the rotor. In this manner, the sealing problem is circumvented. Compared to state of the art air-cooling methods, such a cooling system would increase thermal efficiency of any gas turbine by 6%–8%, because stoichimoetric fuel-air mixtures would be used (maybe even with hydrogen fuel). In addition, these systems would recuperate most of the heat extracted from turbine for cooling, are expected to be highly reliable and to increase specific power of gas turbines by 400% to 500%.


2018 ◽  
pp. 53-57
Author(s):  
Андрій Миколайович Радченко

It is proved a possibility of using the thermohour cooling potential method, developed by the author, for defining the installed (design) refrigeration capacity of term transformer (refrigeration machine), providing a maximum rate of thermo-hour cooling potential increasing according to the current climatic conditions for a definite period of operation.It is proposed to define the effect, gained due to cooling air, in particular at the inlet of GTU, depends on duration and depth of cooling, by thermohour potential ÕS,°С·h, as air temperature decrease Δta  multiplied by duration τ of GTU operation at decreased temperature: ÕS = ∑(Δta ∙°τ), which to some extent characterizes heat load on the cooling system.It is shown that taking into consideration a different rate of annual thermohour cooling potential arising with increasing the installed refrigeration capacity of term transformer, caused by changing the heat load according to current climatic conditions during a year, it is necessary to choose such design heat load on the air cooling system (refrigeration capacity of term transformer) that provides a maximum value of annual thermohour cooling potential or close it with relatively high rates of its increasing.   To define the installed refrigeration capacity, providing a maximum rate of annual thermohour cooling potential increasing, it is analyzed the dependence of annual thermohour cooling potential related to the installed refrigeration capacity of term transformer, from the installed refrigeration capacity of term transformer. As a result of the investigation, it is proposed the method of defining the design heat load (installed refrigeration capacity) of term transformer with maximum rates of increasing thermohour cooling potential, as a further development of methodology of rational designing of them transformers for combustion engine inlet air cooling on the base of thermohour potential, developed by author


2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Hakan Caliskan ◽  
Dae-Young Lee ◽  
Hiki Hong

Abstract In this paper, the effects of regenerative evaporative coolers on the dry desiccant air cooling system are assessed. Thermodynamic analysis is performed point by point on the unmodified (ɛ = 0.67) and modified (ɛ = 1) regenerative evaporative cooler supported systems. It is found that the effectiveness and efficiency of the system were significantly increased by modification. Effectiveness of the system increases from 0.95 to 2.16 for the wet bulb and from 0.63 to 1.43 for dew point effectivenesses, while the exergy efficiency increases from 18.40% to 41.93%. Exergy and energy performances of the system increase 1.28 times and 0.61 times, respectively. Finally, sustainability is increased by 40% with the modification of the regenerative evaporative cooler. Also, changing the regenerative evaporative cooler of the solid desiccant wheel with the effective one can increase the overall system efficiency and performance without changing the sensible heat and desiccant wheels.


Author(s):  
Sandu Constantin ◽  
Dan Brasoveanu

Abstract The thermal efficiency of gas turbines is critically dependent on the temperature of burnt gases at turbine inlet, the higher this temperature the higher the efficiency. Stochiometric combustion would provide maximum efficiency, but in the absence of an internal cooling system, turbine blades cannot tolerate gas temperatures that exceed 1300 K. Therefore, for this temperature, the thermal efficiency of turbine engine is 40% less than theoretical maximum. Conventional air-cooling techniques of turbine blades allow inlet temperatures of about 1500 K on current operating engines yielding thermal efficiency gains of about 6%. New designs, that incorporate advanced air-cooling methods allows inlet temperatures of 1750–1800 K, with a thermal efficiency gain of about 6% relative to current operating engines. This temperature is near the limit allowed by air-cooling systems. Turbine blades can be cooled with air taken from the compressor or with liquid. Cooling systems with air are easier to design but have a relatively low heat transfer capacity and reduce the efficiency of the engine. Some cooling systems with liquid rely on thermal gradients to promote re-circulation from the tip to the root of turbine blades. In this case, the flow and cooling of liquid are restricted. For best results, cooling systems with liquid should use a pump to re-circulate the coolant. In the past, designers tried to place this pump on the engine stator and therefore were unable to avoid high coolant losses because it is impossible to reliably seal the stator-rotor interface. Therefore it was assumed that cooling systems with liquid could not incorporate pumps. This is an unwarranted assumption as shown studying the system in a moving frame of reference that is linked to the rotor. Here is the crucial fact overlooked by previous designers. The relative motion of engine stator with respect to the rotor is sufficient to motivate a cooling pump. Both the pump and heat exchange system that is required to provide rapid cooling of liquid with cold ambient air, could be located within the rotor. Therefore, the entire cooling system can be encapsulated within the rotor and the sealing problem is circumvented. Compared to recent designs that use advanced air-cooling methods, such a liquid cooling system would increase the thermal efficiency by 8%–11% because the temperatures at turbine inlet can reach stoichiometric levels and most of the heat extracted from turbine during cooling is recuperated. The appreciated high reliability of the system will permit a large applicability in aerospace propulsion.


2013 ◽  
Vol 718-720 ◽  
pp. 1687-1690 ◽  
Author(s):  
Sheng Long Wang ◽  
Wen Hao Li ◽  
Yin Hai Ge

In this paper, the research object is composite-cycle air-cooling system. First,gave a brief introduction of the system structure and the working principle in power plant. Then the optimal vacuum calculation model was established with the analysis of performance indicators and the amount of equipment production, consumption power of system. Analyze the impact of the ambient temperature to system optimal vacuum in variable conditions. Lastly, combining the climatic conditions of example, which can be drawn is that when the annual best vacuum is 4.8kPa, the running annual earnings is the highest. This article provides guiding significance for correct understanding and engineering applications of composite-cycle air-cooling systems, also further confirm the feasibility of composite-cycle air-cooling system.


1979 ◽  
Vol 101 (4) ◽  
pp. 516-523 ◽  
Author(s):  
James C. Eastwood

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.


Author(s):  
Hiroyuki Yamazaki ◽  
Yoshiaki Nishimura ◽  
Masahiro Abe ◽  
Kazumasa Takata ◽  
Satoshi Hada ◽  
...  

Tohoku Electric Power Company, Inc. (Tohoku-EPCO) has been adopting cutting-edge gas turbines for gas turbine combined cycle (GTCC) power plants to contribute for reduction of energy consumption, and making a continuous effort to study the next generation gas turbines to further improve GTCC power plants efficiency and flexibility. Tohoku-EPCO and Mitsubishi Hitachi Power Systems, Ltd (MHPS) developed “forced air cooling system” as a brand-new combustor cooling system for the next generation GTCC system in a collaborative project. The forced air cooling system can be applied to gas turbines with a turbine inlet temperature (TIT) of 1600deg.C or more by controlling the cooling air temperature and the amount of cooling air. Recently, the forced air cooling system verification test has been completed successfully at a demonstration power plant located within MHPS Takasago Works (T-point). Since the forced air cooling system has been verified, the 1650deg.C class next generation GTCC power plant with the forced air cooling system is now being developed. Final confirmation test of 1650deg.C class next generation GTCC system will be carried out in 2020.


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