scholarly journals ОХОЛОДЖЕННЯ НАДДУВНОГО ПОВІТРЯ ГОЛОВНОГО СУДНОВОГО ДВИГУНА АБСОРБЦІЙНОЮ БРОМИСТОЛІТІЄВОЮ ХОЛОДИЛЬНОЮ МАШИНОЮ В ЕКВАТОРІАЛЬНИХ ШИРОТАХ

2020 ◽  
pp. 30-35
Author(s):  
Андрій Миколайович Радченко ◽  
Дмитро Вікторович Коновалов ◽  
Іван Володимирович Калініченко ◽  
Чен Нінь ◽  
Хан Баочен

The efficiency of cooling the scavenge air of the main low-speed engine of the transport vessel during operation in the equatorial tropical latitudes is analyzed. The peculiarity of the tropical climate is the high relative humidity of the air at the same time its high temperatures and temperatures of seawater. The cooling of the scavenge air with an absorption lithium bromide chiller by transforming the scavenge air heat into the cold was investigated. With this, the potentially possible minimum temperature of the cooled air was determined considering the temperature of the cold water (coolant) from the absorption lithium bromide chiller and the temperature differences in the heat exchangers of the intermediate water circuit of cooling. Absorption lithium bromide chillers are characterized by high efficiency of transformation of waste heat into cold - high coefficients of performance. Circuit-design solution of three-stage cooling system of scavenging air of ship's main engine - in high-temperature (cogeneration) stage using the extracted heat of scavenging air to get cold with absorption chiller and traditional stage for cooling scavenge air by seawater and low-temperature cooling stage by absorption chiller. The effect of deeper cooling of the scavenge air was determined in comparison with the cooling of the scavenge air with seawater, taking into account the changing climatic conditions during the route of the vessel. It is shown that due to the high efficiency of heat transformation in absorption chillers (high coefficients of performance 0.7…0.8), there is a significant amount of excess heat of scavenging air over the heat required to cool it to 22 °C, which reaches almost half of the available scavenge air heat on the Shanghai-Singapore-Shanghai route. This reveals the possibility of additional cooling the inlet of the turbocharger of the engine with the achieving almost double fuel economy due to the cooling of all cycle air of the low-speed engine, including the air at the inlet.

2020 ◽  
pp. 18-23
Author(s):  
Роман Миколайович Радченко ◽  
Дмитро Вікторович Коновалов ◽  
Максим Андрійович Пирисунько ◽  
Чжан Цян ◽  
Луо Зевей

The efficiency of air cooling at the inlet of the main low speed engine of a transport vessel during operation in tropical climatic conditions on the Shanghai-Karachi-Shanghai route was analyzed. The peculiarity of the tropical climate is the high relative humidity of the air at the same time its high temperatures, and hence the increased thermal load on the cooling system, which requires efficient transformation of the waste heat into the cold in the case of the use of waste heat recovery refrigeration machines. The cooling of the air at the inlet of the low speed engine by absorption lithium bromide chillers, which are characterized by high efficiency of transformation of waste heat into cold – by high coefficients of performance, is investigated. A schematic-construction solution of the air cooling system at the inlet of the ship's main engine using the heat of exhaust gases by an absorption chiller is proposed and analyzed. With this the cooling potential of the inlet air cooling from the current ambient air temperature to 15 ° C and the corresponding heat consumption for the operation of the adsorption chiller, on the one hand, was compared with the available exhaust gas heat potential, on the other hand. The effect of using the exhaust gas heat to cool the air at the inlet of the engine has been analyzed taking into account the changing climatic conditions during the voyage. Enhancement of fuel efficiency of the ship's engine by reducing the inlet air temperature were evaluated by current values of the reduction in specific and total fuel consumption. It is shown that due to the high efficiency of heat conversion in absorption chillers (high coefficients of performance 0.7…0.8), a significant amount of excessive exhaust gas heat over the heat required to cool the ambient air at the inlet of the engine to 15 ° C, which reaches almost half of the available exhaust gas heat during the Shanghai-Karachi-Shanghai route. This reveals the possibility of additional cooling a scavenge air too with almost double fuel economy due to the cooling of all cycle air of the low speed engine, including the air at the inlet.


2020 ◽  
pp. 17-21
Author(s):  
Роман Миколайович Радченко ◽  
Максим Андрійович Пирисунько ◽  
Нiн Чен ◽  
Баочен Хан

The efficiency of air cooling at the inlet of the main low-speed engine turbocharger of a transport vessel during operation in tropical climatic conditions on the Shanghai-Singapore-Shanghai route was analyzed. A feature of the tropical climate is the high relative humidity, respectively, moisture content at its simultaneously high temperatures. The cooling of the air at the inlet of a low-speed engine with an ejector chiller by transforming the waste heat of exhaust gases into cold was studied. The ejector chiller is used as the most simple and reliable in operation. However, the efficiency of the transformation of heat into cold by ejector chillers is low - low thermal coefficients.A design solution of the system for cooling air at the inlet of the ship's main engine using the heat of the exhaust gases by an ejector chiller is proposed and analyzed. The effect of using the heat of the exhaust gases to cool the air at the engine inlet is analyzed taking into account the variable climatic conditions during the voyage of the vessel. It is shown that because of the insufficiently high efficiency of transforming the waste heat of the exhaust gases by an ejector chiller (low thermal coefficients), the obtained cooling capacity is not sufficient for cooling the air at the inlet of the turbocompressor during operation of a marine engine in tropical climatic conditions. Therefore, the possibility of use in the ejector chiller of additional heat of charge air, which is removed by cooling water, is also considered. It is shown that the use of the heat of exhaust gases and charge air for cooling the air at the engine inlet in an ejector chiller makes it possible to double decrease the air temperature at the inlet of the main engine by 20-30 °C when the vessel operates in tropical climatic conditions on a voyage lines Shanghai-Singapore-Shanghai. This, in turn, provides an almost twice fuel consumption reduction in compared with its reduction in the case when the ejector chiller uses only the heat of the exhaust gases.


2020 ◽  
pp. 24-29
Author(s):  
Микола Іванович Радченко ◽  
Дмитро Вікторович Коновалов ◽  
Чжан Цян ◽  
Лю Шаоцзюнь ◽  
Луо Зевей ◽  
...  

The efficiency of cooling the scavenge air of the main low-speed engine of the transport vessel during operation in the equatorial tropical latitudes is analyzed. The peculiarity of the tropical climate is the high relative humidity of the air at the same time its high temperatures and temperatures of seawater. The cooling of the s scavenge air with a refrigerant ejector chiller was investigated by transforming the scavenge air heat into the cold. With this, the potentially possible minimum temperature of the cooled air was determined considering the boiling temperature of the refrigerant and the temperature differences in the heat exchangers of the intermediate water cooling circuit. Refrigerant ejector chiller is used as the most simple and reliable in design. However, the efficiency of converting the heat to cold by ejector chillers is low: their coefficients of performance are approximately 0.3. Circuit-design solution of three-stage cooling system of scavenging air of ship's main engine - in high-temperature (cogeneration) stage using the extracted heat of scavenging air to get cold with ejector chiller and traditional stage for cooling scavenge air by seawater and low-temperature cooling stage by ejector chiller. The effect of deeper cooling of the scavenge air was determined in comparison with the cooling of the scavenge air with seawater, taking into account the changing climatic conditions during the route of the vessel. It is shown that because of the insufficiently high efficiency of transformation of the scavenge air heat by the ejector chiller (low coefficients of performance) the obtained cooling capacity is not sufficient to cool the scavenge air to a potentially possible minimum temperature of 22 °C when operating the ship engine in tropical climates. However, the heat deficit is relatively small and can be covered by the use of additional exhaust gas heat.


2020 ◽  
pp. 344-344
Author(s):  
Andrii Radchenko ◽  
Ionut-Cristian Scurtu ◽  
Mykola Radchenko ◽  
Serhiy Forduy ◽  
Anatoliy Zubarev

The fuel efficiency of gas engines is effected by the temperature of intake air at the suction of turbocharger. The data on dependence of fuel consumption and engine electric power on the intake air temperature were monitored for Jenbacher gas engine JMS 420 GS-N.LC to evaluate its influence. A waste heat of engine is rejected for heating water to the temperature of about 90??. The heat received is used in absorption lithium-bromide chiller to produce a cold in the form of chilled water. A cooling capacity of absorption chiller firstly is spent for technological needs and then for feeding the central air conditioner for cooling the ambient air incoming the engine room, from where the air is sucked by the engine turbocharger. The monitoring data revealed the reserves to enhance the efficiency of traditional cooling system of intake air by absorption chiller through deeper cooling. This concept can be realized in two ways: by addition cooling a chilled water from absorption chiller to about 5-7?? for feeding engine intake air cooler or by two-stage cooling with precooling ambient air by chilled water from ACh in the first stage and subsequent deep cooling air to the temperatures 7-10?? in the second stage of intake air cooler by using a refrigerant as a coolant. In both cases the ejector chiller could be applied as the most simple in design.


2018 ◽  
pp. 19-22
Author(s):  
Андрій Миколайович Радченко ◽  
Євген Іванович Трушляков ◽  
Сергій Анатолійович Кантор ◽  
Богдан Сергійович Портной

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


2014 ◽  
Vol 984-985 ◽  
pp. 784-791
Author(s):  
C. P. Christin Raj ◽  
S.A. Ananthapuri Surendran ◽  
B. Amjathkhan ◽  
J.Antony Baksi Metilda ◽  
S.Eben Devaraj ◽  
...  

In order to reduce the entry of moisture, salt, sand and other external contaminations into the nacelle and also to reduce the fan noise which reaches the exterior, in this work a study of an innovative cooling system for off-shore wind turbine has been carried out. The new cooling technique is based on the use of nanofluids (engineered colloidal suspensions of nanoparticles in a base fluid). Nanofluids allow to increase the thermal conductivity of fluids and so to reduce the heat exchange surface and the heat transfer fluid flow rate due to the increased heat capacity. To reduce the amount of nanofluids circulating in the cooling system, the performance of a two-stage cooling circuit has been investigated. The first circuit takes the heat out of the generator and of the accessories whereas the second circuit, coupled with the first via an heat exchanger, dissipates the heat into the ambient. For the second circuit two options have been investigated. In the first solution the waste heat is dispersed using the tower as dissipator whereas in the second option the waste heat is exchanged with a titanium heat exchanger using marine water as heat transfer fluid.Both solutions assure high efficiency of heat exchange, long technical life expectancy and limited maintenance requirements.Keywords: Wind turbine, nanofluid, cooling system.


2014 ◽  
Vol 18 (2) ◽  
pp. 543-554 ◽  
Author(s):  
Risi de ◽  
Marco Milanese ◽  
Gianpiero Colangelo ◽  
Domenico Laforgia

The efficiency of cooling system is critical for wind turbines, particularly during the hot season, when high temperatures could damage the electric generator and mechanical parts of the turbine. The cooling system proposed in this paper is able to increase the efficiency of heat transfer with the use of nanofluids and the wind turbine tower as a heat exchanger to dissipate waste heat in the environment. In this study the use of Al2O3-water nanofluids has been considered. The results of this investigation appear encouraging because they have shown that the proposed new solution is able to assure highly efficient heat transfer and to limit thermal stresses on the electrical and mechanical components of wind turbines.


Author(s):  
Yang Hu ◽  
Laura A. Schaefer ◽  
Volker Hartkopf

The Building Energy Data Book (2009) [1] shows that commercial and residential buildings in the U.S. consume 39.9% of the primary energy and contribute 39% of the total CO2 emissions. In the operation of buildings, 41.8% of building energy consumption is provided for building cooling, heating, domestic hot water, and ventilation for commercial buildings, while in residential buildings, this percentage increases to 58%. In energy system analysis, the energy approach is the traditional method of assessing the way energy is used in an operation. However, an energy balance provides no information on the degradation of energy or resources during a process. The concept of exergy combines the first law and second law of thermodynamics. The exergy analysis clearly quantifies the energy quality match between the supply and demand sides, and also addresses the exergy destruction (entropy generation) in each component. In this paper, a solar thermal driven absorption cooling system was analyzed for providing cooling to a building, the Intelligent Workplace South Zone at Carnegie Mellon University. The system includes a 52 m2 parabolic trough solar collector, and a 16 kW (4 tons) two-stage lithium bromide absorption chiller. The energy model and newly developed two-stage lithium bromide absorption chiller are programmed and integrated in Engineering Equation Solver (EES). The temperature, enthalpy, entropy, mass flow rate, and mass fraction of lithium bromide in the solar absorption system were presented in steady state operation. The exergy destruction in each component is calculated. The exergy destructions for the solar collector, generator, absorber, and heat exchangers were significantly higher than those in evaporator, condenser and expansion valves, the overall energy and exegetic efficiency were also calculated.


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