Innovative Turbine Intake Air Cooling Systems and Their Rational Designing

Innovative Turbine Intake Air Cooling Systems and Their Rational Designing / A. Radchenko, E. Trushliakov, K. Kosowski, D. Mikielewicz, M. Radchenko // Energies. – 2020. – № 13 (23). – P. 6201.Abstract: 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. Amethod 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 determiningtheoptimalvalueofcoolingcapacity,providingtheminimumsystemsizesatmaximum 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 beyondthefirstmaximumrate. Therationalvalueofdesigncoolingcapacityprovidespracticallythe maximum annual fuel saving but with the sizes of cooling systems reduced by 15 to 20% due to the correspondinglyreduceddesigncoolingcapacityofthesystemsascomparedwiththeirvaluesdefined 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 applyingtheenergysavingtechnologies,forinstance,basedon the thermalstoragewithaccumulating 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.)

Statistical Method to Define Rational Heat Loads on Railway Air Conditioning System for Changeable Climatic Conditions

Statistical Method to Define Rational Heat Loads on Railway Air Conditioning System for Changeable Climatic Conditions / A. Radchenko, M. Radchenko, E. Trushliakov, S. Kantor, V. Tkachenko // 5th Intern. Conf. on Systems and Informatics (ICSAI). – Nanjing, 2019. – P. 1294–1298A statistical method of defining rational heat loads on railway air conditioning system with taking into account the current changeable heat loads corresponding to current climatic conditions on the route lines has been proposed. According to this method the rational designed heat load on refrigeration machine, matching current changeable climatic conditions on the route lines and providing efficient operation of refrigeration machine of air conditioning system with maximum (close maximum) refrigeration capacity production (refrigeration output) for definite period of operation (monthly, seasonal or annular period) is defined through statistical treatment of data sets of hourly refrigeration capacities corresponding to the current climatic conditions on the route lines by their summation during the operation period for various installed (designed) refrigeration capacities of machine. The method is based on the hypothesis of different rates of refrigeration capacity production increment for the period of operation with increasing the installed refrigeration capacity, that is revealed in slowing down the rate of refrigeration capacity production increment at over increased installed refrigeration capacity. Proceeding from this hypothesis the rational value of heat load on railway air conditioning system is chosen close to the value that corresponds to the maximum refrigeration capacity production for the period of operation. Such rational value of designed heat load on railway air conditioning system provides reduction of refrigeration machine capacity and its cost by 15…20 % as compared with traditional its designing for the maximum heat load. The operation of refrigeration machine in partial modes for enlarged installed refrigeration capacity chosen traditionally – for the maximum heat load needs application of expensive inventor compressors to control motor speed matching current changeable heat loads

Enhancing heat efficiency of air coolers of air conditioning systems by injector refrigerant circulation

Radchenko, M. Enhancing heat efficiency of air coolers of air conditioning systems by injector refrigerant circulation = Підвищення теплової ефективності повітроохолоджувачів систем кондиціонування інжектором / M. Radchenko, E. Trushliakov, A. Radchenko // Матеріали XI міжнар. наук.-техн. конф. "Інновації в суднобудуванні та океанотехніці". В 2 т. – Миколаїв : НУК, 2020. – Т. 1. – С. 581–491.Анотація: Один з найпривабливіших резервів підвищення ефективності систем кондиціонування та їх застосування в різних областях полягає в ефективній роботі повітряних охолоджувачів (випарників холодоагенту). Концепція доопрацювання ефективної роботи випарників холодоагенту з неповним випаровуванням холодоагенту за рахунок рециркуляції рідкого холодоагенту інжектором (реактивним насосом) знайшла новий імпульс для подальших застосувань у зовнішніх повітряних переробних установках, щоб відповідати різним нагріванням зовнішнього тепла відповідно до фактичних кліматичних умов Умови в приміщенні відповідали різним тепловим навантаженням у приміщеннях в системах кондиціювання без змінного холодильного потоку. Запропонована концепція підвищення теплової ефективності теплообмінників з киплячими холодоагентами всередині каналів розроблена для вирішення проблеми нерівномірного розподілу холодоагенту у впускних колекторах (головках) для мікроканальних теплообмінників або між котушками холодоагенту та нерівними зовнішнім боковим нагріванням повітря на змійовиках холодоагенту шляхом переповнення їх за допомогою рециркуляції рідкого холодоагенту, що забезпечує виключення кінцевої стадії висихання випаровування холодоагенту з низькою інтенсивністю передачі тепла. Таким чином, за рахунок виключення внутрішньої проблеми нерівномірного розподілу холодоагенту та низької інтенсивності передачі тепла випаровуванням холодоагенту в каналах загальна проблема підвищення ефективності теплообмінників киплячим холодоагентом всередині каналів перетворюється на зовнішню проблему передачі тепла на повітряній стороні.Abstract: One of the most attractive reserves of enhancing the efficiency of air conditioning (AC) systems and their application in various fields consists in efficient operation of air coolers (refrigerant evaporators). A retrofit concept of efficient operation of refrigerant evaporators with incomplete refrigerant evaporation due to liquid refrigerant recirculation by injector (jet pump) has found a new impulse for further applications in outdoor air processing units (OAPU) to match varying outdoor heat loads according to actual climatic conditions and for indoor air coils to match varying indoor heat loads in ductless Variable Refrigerant Flow (VRF) AC systems. A proposed concept of enhancing heat efficiency of heat exchangers with boiling refrigerants inside channels is intended to solve the problem of uneven refrigerant distribution in inlet manifolds (headers) for microchannel heat exchangers or between refrigerant coils and of uneven outside air heat loads on refrigerant coils by over filling them through liquid refrigerant injector recirculation that provides excluding the final dry-out stage of refrigerant evaporation with low intensity of heat transfer. Thus, due to excluding the internal problem of refrigerant uneven distribution and low intensity of heat transfer of refrigerant evaporation in channels the general problem of enhancing the efficiency of heat exchangers with boiling refrigerants inside channels is transformed into the external problem of heat transfer on air side

New dimensions and dead ends in ai development: impact and responsibility of science and higher education

AI development demonstrates shows excellent results in the performance of individual operations of the intellect, but it fails to simplify the performance of tasks, instead of their creative and complex solution. AI cannot set goals, and it understands their achievement in a pattern, and it cannot create a new pattern of interaction, but it brings the fulfillment of existing such patterns to the point of absurdity. Science and higher education are called to carry out permanent support of AI activities and adjustment of tasks for AI

Research of the Aerothermopressor Cooling System of Charge Air of a Marine Internal Combustion Engine Under Variable Climatic Conditions of Operation

Research of the Aerothermopressor Cooling System of Charge Air of a Marine Internal Combustion Engine Under Variable Climatic Conditions of Operation / D. Konovalov, E. Trushliakov, M. Radchenko, H. Kobalava, V. Maksymov // Grabchenko’s Intern. Conf. on Advanced Manufacturing Processes. – Odessa, 2020. – P. 520–529.Abstract. Principle of charge air cooling of the internal combustion engine with an aerothermopressor is proposed. It is implemented on the transport ship regular line. Arising thermogasdynamic compression allows increasing the air pressure. The aerothermopressor application in the charge air cooling systems makes it possible to reduce the power consumed by compressors, Nc by 3–10 %, thereby the engine power is increased by 1–3 % and the specific fuel consumption is decreased by 2–4 %. It is established that in case of increasing the ambient air temperature tamb at the turbocharger input the effect from the aerothermopressor used for cooling of the charge air is increased: the turbocharger power reduction DNC is increased with a corresponding increase in engine power and a decrease in specific fuel consumption. The relative (related to air flow) water mass flow is determined, which has to be injected at completely evaporated in a thermal overpressure: 0.02–0.05 (2–5 %)

Science trends and Digital immortality: AI accelerates movement towards an unattainable goal

The development of AI, social networks, digital technologies, and in particular Big Data, has brought humanity closer to digital immortality. Despite the risks of psychological, social and technological adaptation to using the possibilities of digital immortality, it is confidently introduced into various spheres of social life. However, currently it is mainly about simulating immortality, since decision-making is still beyond the reach of this technology

Топливная эффективность охлаждения наддувочного воздуха главного судового дизеля теплоиспользующей холодильной машиной на рейсовой линии

Радченко, Р. Н. Топливная эффективность охлаждения наддувочного воздуха главного судового дизеля теплоиспользующей холодильной машиной на рейсовой линии = Fuel efficiency of the main marine diesel scavenge air cooling by the waste heat recovery chiller on the route line / Р. Н. Радченко, Н. С. Богданов // Зб. наук. пр. НУК. – Миколаїв : НУК, 2016. – № 3 (465). – С. 43–50.Визначена раціональна температура наддувного повітря після відведення від нього теплоти у високотемпературному ступені охолоджувача наддувного повітря, яка обмежує кількість теплоти, що використовується хладоновою ежекторною холодильною машиною для глибокого охолодження наддувного повітря у високотемпературному ступені охолоджувача наддувного повітря суднового малообертового дизеля для кліматичних умов експлуатації судна на рейсовій лінії. Розраховані зменшення питомої витрати палива та економія палива в результаті охолодження наддувного повітря суднового малообертового дизеля для кліматичних умов експлуатації судна на рейсовій лінії Одеса-Йокогама.It is considered a waste heat recovery scavenge air cooling system that consists of three stage air cooler: the first stage extracting a high potential heat from the scavenge air after the turbo-charger (so called utilizing or cogenerative stage), the second convention stage using sea water as cooling medium and the third stage using a cold from the waste heat recovery refrigerant ejector chiller utilizing the heat of scavenge air extracting in the first stage. The heat load on the first high-temperature stage of the scavenge air cooler has been supposed as the heat source to produce a refrigeration capacity wasted for scavenge air deep cooling in the low temperature section by refrigerant ejector chiller of waste heat recovery cooling system. It is shown that a scavenge air heat is quite enough to cover the heat wasted for addition scavenge air cooling from the temperature of air after a convention sea water cooler to the potential minimal temperature that provides reducing the engine fuel consumption. The rational temperature of the scavenge air after heat extraction from it in the high-temperature stage of the scavenge air cooler that limits a magnitude of the heat to be used by waste heat recovery refrigeration ejector chiller for scavenge air deep cooling in the low temperature stage of the scavenge air cooler of the marine low speed diesel engine for climate conditions of the ship performance on the route line has been defined. A reduction of specific fuel consumption and fuel saving due to scavenge air cooling for the main marine low speed diesel engine for climate conditions of the ship performance on the Odessa-Yokogama route line were estimated.Определена рациональная температура наддувочного воздуха после отвода от него теплоты в высокотемпературной ступени охладителя наддувочного воздуха, лимитирующая количество теплоты, используемой хладоновой эжекторной холодильной машиной для глубокого охлаждения наддувочного воздуха в низкотемпературной ступени охладителя наддувочного воздуха судового малооборотного дизеля для климатических условий эксплуатации судна на рейсовой линии. Рассчитаны уменьшение удельного расхода топлива и экономия топлива в результате охлаждения наддувочного воздуха судового малооборотного дизеля для климатических условий эксплуатации судна на рейсовой линии Одесса-Йокогама

Оценка топливной эффективности охлаждения воздуха на входе газовых турбин для климатических условий разных регионов Ливии

Рамзи Камел Эл Герби Оценка топливной эффективности охлаждения воздуха на входе газовых турбин для климатических условий разных регионов Ливии = A fuel saving estimation of gas turbine intake air cooling for climatic conditions in various regions of Libya / Рамзи Камел Эл Герби, Н. И. Радченко // Зб. наук. пр. НУК. – Миколаїв : НУК, 2016. – № 2 (464). – С. 64–70.Виконана оцінка економії палива за рахунок охолодження повітря на вході газових турбін до різних температур термотрансформаторами різних типів для регіонів Лівії, в яких зосереджено виробництво електричної енергії газотурбогенераторами. Показано, що охолодження повітря на вході газових турбін до 10 і 7°С в абсорбційній водоаміачній і хладоновій ежекторній холодильних машинах забезпечує в 1,5…2,0 рази більшу річну економію палива порівняно з абсорбційною бромисто-літієвою холодильною машиною, яка забезпечує зниження температури повітря на вході газових турбін до 15°С.Gas turbine generators are the base of the electricity industry in Libya. The gas turbine operation conditions in Libya are characterized by high intake air temperatures and their fuel efficiency decrease, thus requiring the intake air cooling. The absorption lithium-bromide chiller and the absorption aqua-ammonia and refrigerant ejector chillers using the turbine exhaust gases heat are considered as waste heat thermotransformers; the former provides the gas turbine intake air temperature decrease down to 15°С, while the latter – to 10°С and lower. The assessment of fuel saving has been performed. It is achieved due to the gas turbine inlet air cooling down to various temperatures carried out by thermotransformers of different types for the regions of Libya where the turbogenerators electricity production is concentrated. It was shown that the gas turbine intake air cooling down to the temperatures of 10 and 7°С by the absorption aqua-ammonia and refrigerant ejector chillers provides 1.5…2.0 times larger annular fuel saving as compared to the absorption lithium-bromide chiller providing the gas turbine intake air temperature decrease down to 15°С. As a result, the higher efficiency of the gas turbine intake air deep cooling down to the temperatures of 10 and 7°С by the absorption aqua-ammonia and refrigerant ejector chillers was proved. The annular fuel saving due to the air cooling at the inlet of gas turbine generators by thermotransformers of different types was assessed for the regions of Libya where the electricity production is concentrated.Выполнена оценка годовой экономии топлива за счет охлаждения воздуха на входе газовых турбин до разных температур термотрансформаторами разных типов для регионов Ливии, в которых сосредоточено производство электрической энергии газотурбогенераторами. Показано, что охлаждение воздуха на входе газовых турбин до 10 и 7°С в абсорбционной водоаммиачной и хладоновой эжекторной холодильных машинах обеспечивает в 1,5…2,0 раза большую годовую экономию топлива по сравнению с абсорбционной бромисто-литиевой холодильной машиной, обеспечивающая снижение температуры воздуха на входе газовых турбин до 15°С

Los parámetros óptimos del seguro agrícola de los productos en Ucrania

EN : The article deals with the complex indicative forecasting of agricultural insurance parameters, which have approximate empirical dependences of variables and provide approximation of actuarial calculations of the franchise, in order to optimize the rates of insurance compensation for losses in agricultural production. The tools for minimizing the risks of agricultural production are substantiated. The typology of instruments for regulating the risks of agricultural production by transferring their risk distribution in the institutional environment and market infrastructure is studied. It is proved that vertical integration has a positive effect of compensation for losses of agricultural production, taking into account alternative diversification combinations with actual variables and the occurrence of a certain insurance event. Multicriteria optimization of the parameters of partial distribution of risks of agricultural production, which simultaneously provide the maximum possible value of the expected return with a minimum value of the risk of the portfolio of assets of agricultural enterprises, is fulfilled. The utility function for accidental consequences in agricultural insurance is substantiated, as it guarantees the effective indicator of income at variable values of uncertainty. Approximate empirical dependences of variables are determined, which provide approximation of actuarial calculations of the franchise, in order to optimize the rates of insurance indemnity in agricultural production. Models of indicative forecasting of optimal parameters of agricultural insurance on the market of agricultural products of Ukraine on insurance payments and insurance premiums, which have a decreasing function, have been developed; insured sum and franchise have dynamic fluctuations

Advanced Method of Variable Refrigerant Flow (VRF) System Design to Forecast on Site Operation—Part 3: Optimal Solutions to Minimize Sizes

Outdoor air conditioning systems (ACS) are used as autonomic systems as well as in combined outdoor and indoor ACS of the variable refrigerant flow (VRF) type, with variable speed compressors (VSC) as their advanced version. Methods for determining the optimal value of refrigeration capacity and providing the maximum rate of the summarized annual refrigeration energy generation increment, according to its needs at minimum compressor sizes and rational values, are applied to reveal the reserves for reducing the designed (installed) refrigeration capacity, thus enabling us to practically achieve maximum annual refrigeration energy generation as the primary criterion at the second stage of the general design methodology previously developed by the authors. The principle of sharing the total thermal load on the ACS between the ranges of changeable loads for outdoor air precooling, and a relatively stable load range for further processing air are used as its basis. According to this principle, the changeable thermal load range is chosen as the object for energy saving by recuperating the excessive refrigeration generated at lowered loading in order to compensate for the increased loads, thereby matching actual duties at a reduced designed refrigeration capacity. The method allows us to determine the corresponding level of regulated loads (LRL) of SRC and the load range of compressor operation to minimize sizes