scholarly journals ПОДХОД К АНАЛИЗУ ЭФФЕКТИВНОСТИ РЕГУЛИРОВАНИЯ ХОЛОДОПРОИЗВОДИТЕЛЬНОСТИ СИСТЕМ КОНДИЦИОНИРОВАНИЯ ПРИТОЧНОГО ВОЗДУХА

2018 ◽  
pp. 29-33
Author(s):  
Евгений Иванович Трушляков ◽  
Николай Иванович Радченко ◽  
Вениамин Сергеевич Ткаченко
Keyword(s):  
Electric Motor ◽  
Air Conditioning ◽  
Frequency Converter ◽  
Piston Compressor ◽  
Ambient Air ◽  
Climatic Conditions ◽  
Coefficient Of Performance ◽  
Air Cooling ◽  
Refrigeration Capacity ◽  
Air Conditioning Systems

It is determined that the operation of ambient air conditioning systems (AACS) has significant fluctuations in the heat load in accordance with current climatic conditions. This makes very problematic the application of refrigeration compressors with frequency converters, which are very effective for controlling the refrigeration capacity in closed air conditioning systems, in which the temperature control range and, accordingly, fluctuations in thermal load are insignificant in comparison with the ambient air cooling. For the purpose of analyzing the efficiency of controlling the refrigeration capacity of the AACS by changing the electric motor speed of the piston compressor in current climatic conditions, the entire range of changing current thermal loads is divided into two parts according to controlling the refrigeration capacity by appling a frequency converter: the part of effective cooling capacity adjustment without energy losses (without reducing the coefficient of performance) from nominal to its threshold value and the part of reduced refrigeration capacity without its controlling by a frequency converter. It is revealed that for the warmest summer month, the proportion of refrigeration capacity spent for cooling ambient air to the temperature of 10 °C with 50 % frequency controlling the refrigeration capacity is about 10 % of the total amount of that could be produced at nominal refrigeration capacity. At higher temperatures of cooled air is even less. This shows the low efficiency of controlling the refrigeration capacity of the AACS by changing the speed of rotation of the piston compressor electric motor and the need to use other methods of controlling the refrigeration capacity. The proposed approach to analyzing the efficiency of controlling the refrigeration capacity of AACS in current climatic conditions allows not only to estimate the efficiency of refrigeration capacity controlling method but also to reveal the reserves for increasing the efficiency of applying the available refrigeration capacity

scholarly journals АНАЛІЗ ЕКОЛОГІЧНОЇ ЕФЕКТИВНОСТІ СИСТЕМ КОНДИЦІЮВАННЯ ПОВІТРЯ КОМБІНОВАНОГО ТИПУ

2019 ◽  
pp. 24-29
Author(s):  
Євген Іванович Трушляков ◽  
Андрій Миколайович Радченко ◽  
Сергій Георгійович Фордуй ◽  
Анатолій Анатолійович Зубарєв ◽  
Сергій Анатолійович Кантор ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Air Conditioning ◽  
Maximum Growth ◽  
Ambient Air ◽  
Cooling Capacity ◽  
Maximum Growth Rate ◽  
Climatic Conditions ◽  
Air Cooling ◽  
Carbon Dioxide Co2 ◽  
Air Conditioning Systems

Since the supply air conditioning systems operation effect depends on the cooling duration and depth, it is quite justified to estimate it by the value of the specific annual cold production, which is the product of the necessary cooling capacity for cooling the air to the target temperature multiplied by duration of operation at a given cooling capacity and, thus, considers current climatic conditions. Obviously, the realization of the cooling potential (air conditioning) of the ambient air depends on the installed (design) cooling capacity of the air conditioning units, which, in turn, must considering fluctuations in thermal loads by the current variable thermal and humidity parameters of the ambient air. With an increase in the temperature of the ambient air, fuel consumption for the production of a unit capacity (mechanical/electrical energy) increases, and, accordingly, the more harmful substances are removed to the atmosphere with exhaust gases. To reduce the negative impact of unproductive fuel consumption during the operation of air conditioning systems at elevated ambient temperatures, resort to various methods for determining the installed cooling capacity of the installation, to reduce it. In the work, the ecological efficiency of air cooling is studied considering the climatic operating conditions for the Kyiv city that are variable during the year. The annual reduction in emissions of carbon dioxide CO2 and nitric oxide NOX was chosen as indicators for assessing the environmental effect of air cooling. It has been shown that when choosing the installed cooling capacity, by the method of ensuring the maximum growth rate of the annual cold production considering the increase in the installed cooling capacity of the chiller, there is a greater reduction in specific fuel consumption compared to the method of choosing the maximum annual cold production, respectively, and harmful emissions. When comparing the methods for choosing the design cooling capacity, air cooling to 15 °C provides a reduction in carbon dioxide CO2 emissions of more than 34 t for 2017 for the climatic conditions of Kiev, in favor of the method of ensuring the maximum growth rate of annual cold production, and nitric oxide NOX – about 5,8 t.

scholarly journals МЕТОД ВИЗНАЧЕННЯ ТЕПЛОВОГО НАВАНТАЖЕННЯ СИСТЕМИ КОНДИЦІЮВАННЯ ПОВІТРЯ ЗА МАКСИМАЛЬНИМ ТЕМПОМ ПРИРОЩЕННЯ ХОЛОДОПРОДУКТИВНОСТІ (на прикладі кондиціювання повітря енергетичного призначення)

2018 ◽  
pp. 44-48
Author(s):  
Микола Іванович Радченко ◽  
Євген Іванович Трушляков ◽  
Сергій Анатолійович Кантор ◽  
Богдан Сергійович Портной ◽  
Анатолій Анатолійович Зубарєв
Keyword(s):  
Thermal Load ◽  
Air Conditioning ◽  
Lithium Bromide ◽  
Ambient Air ◽  
Climatic Conditions ◽  
Annual Production ◽  
Air Cooling ◽  
Two Stage ◽  
Air Conditioning System ◽  
Refrigeration Capacity

It is justified the necessity of taking into consideration changes in thermal loads on the air conditioning system (heat and moisture treatment of air by cooling it with decreasing temperature and moisture content) in accordance with the current climatic conditions of operation. Since the effect of air cooling depends on the duration of its use and the amount of cold consumption, it is suggested that it be determined by the amount of cold spent per year for air conditioning at the GTU inlet, that is, for annual refrigerating capacity. The example of heat-using air conditioning at the inlet of a gas turbine unite (energy–efficient air conditioning systems) analyzes the annual costs of cooling for cooling ambient air to the temperature of 15 °C by an absorption lithium-bromide chiller and two-stage air cooling: to a temperature of 15 °C in an absorption lithium-bromide chiller and down to temperature 10 °С – in a refrigerant ejector chiller as the stages of a two-stage absorption-ejector chiller, depending on the installed (project) refrigerating capacity of waste heat recovery chiller.It is shown that, based on the varying rate of increment in the annual production of cold (annual refrigeration capacity) due to the change in the thermal load in accordance with current climatic conditions, it is necessary to select such a design thermal load for the air conditioning system (installed refrigeration capacity of chillers), which ensures the achievement of maximum or close to it annual production of cold at a relatively high rate of its increment. It is analyzed the dependence of the increment on the annual refrigerated capacity, relative to the installed refrigeration capacity, on the installed refrigeration capacity, in order to determine the installed refrigeration capacity, which provides the maximum rate of increase in the annual refrigerating capacity (annual production of cold). Based on the results of the research, it is proposed the method for determining the rational thermal load of the air conditioning system (installed – the design refrigeration capacity of the chiller) in accordance with the changing climatic conditions of operation during the year, which provides nearby the maximum annual production of cold at relatively high rates of its growth

scholarly journals Gas turbine unite inlet air cooling by using an excessive refrigeration capacity of absorption-ejector chiller in booster air cooler

2018 ◽  
Vol 70 ◽  
pp. 03012 ◽  
Author(s):  
Roman Radchenko ◽  
Andrii Radchenko ◽  
Serhiy Serbin ◽  
Serhiy Kantor ◽  
Bohdan Portnoi
Keyword(s):  
Gas Turbine ◽  
Cooling System ◽  
Ambient Air ◽  
Cooling Capacity ◽  
Climatic Conditions ◽  
Air Cooling ◽  
Two Stage ◽  
Air Cooler ◽  
Refrigeration Capacity ◽  
Heat Loads

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.

scholarly journals ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ СИСТЕМ КОНДИЦІЮВАННЯ ПОВІТРЯ ШЛЯХОМ РОЗПОДІЛУ ТЕПЛОВОГО НАВАНТАЖЕННЯ ЗА СТУПЕНЕВИМ ПРИНЦИПОМ

2019 ◽  
pp. 49-53
Author(s):  
Євген Іванович Трушляков ◽  
Микола Іванович Радченко ◽  
Андрій Миколайович Радченко ◽  
Сергій Георгійович Фордуй ◽  
Сергій Анатолійович Кантор ◽  
...  
Keyword(s):  
Thermal Load ◽  
Air Conditioning ◽  
Rational Design ◽  
Ambient Air ◽  
Cooling Capacity ◽  
Climatic Conditions ◽  
Outlet Temperature ◽  
Thermal Loads ◽  
Air Conditioning System ◽  
Air Conditioning Systems

Maintaining the operation of refrigeration compressors in nominal or close modes by selecting a rational design thermal load and distributing it in response to the behavior of the current thermal load according to the current climatic conditions is one of the promising reserves for improving the energy efficiency of air conditioning systems, which implementation ensures maximum or close to it in the annual cooling production according to air conditioning duties. In general case, the total range of current thermal loads of any air-conditioning system includes a range of unstable loads caused by precooling of ambient air with significant fluctuations in the cooling capacity according to current climatic conditions, and a range of relatively stable cooling capacity expended for further lowering the air temperature from a certain threshold temperature to the final outlet temperature. If a range of stable thermal load can be provided within operating a conventional compressor in a mode close to nominal, then precooling the ambient air with significant fluctuations in thermal load requires adjusting the cooling capacity by using a variable speed compressor or using the excess of heat accumulated at reduced load. Such a stage principle of cooling ensures the operation of refrigerating machines matching the behavior of current thermal loads of any air-conditioning system, whether the central air conditioning system with ambient air procession in the central air conditioner or its combination with the local indoors recirculation air conditioning systems in the air-conditioning system. in essence, as combinations of subsystems – precooling of ambient air with the regulation of cooling capacity and subsequent cooling air to the mouth of the set point temperature under relatively stable thermal load.

scholarly journals ВИЗНАЧЕННЯ ПРОЕКТНОЇ ХОЛОДОПРОДУКТИВНОСТІ СИСТЕМИ КОНДИЦІЮВАННЯ ПОВІТРЯ В КОНКРЕТНИХ КЛІМАТИЧНИХ УМОВАХ І РІЗНИМИ МЕТОДАМИ

2019 ◽  
pp. 15-19
Author(s):  
Євген Іванович Трушляков ◽  
Андрій Миколайович Радченко ◽  
Сергій Анатолійович Кантор ◽  
Веніамін Сергійович Ткаченко ◽  
Сергій Георгійович Фордуй ◽  
...  
Keyword(s):  
Power Plant ◽  
Fuel Consumption ◽  
Air Conditioning ◽  
Maximum Rate ◽  
Cooling Capacity ◽  
Climatic Conditions ◽  
Temperate Climate ◽  
Air Cooling ◽  
Air Conditioning System ◽  
Air Conditioning Systems

The cold output for the heat-moisture treatment of ambient air in air conditioning systems depends on its parameters (temperature and relative humidity), which vary significantly during operation. To determine the installed (design) cooling capacity of air conditioning system chillers, it is proposed to use a reduction in fuel consumption of a power plant or cooling capacity generation following its current conditioning spending over a certain period, since both of these indicators characterize the efficiency of using the installed cooling capacities of the air conditioning system. To extend the results of the investigation to a wide range of air conditioning units, two methods were used to determine the design cooling capacity (refrigerating capacity): by the maximum annual value and by the maximum growth rate of the efficiency indicator. The first method allows choosing the design cooling capacity, which provides a maximum annual reduction in the specific fuel consumption due to air cooling or maximum cooling capacity generation, which is necessary for air cooling following current climatic conditions. The second method allows determining the minimum design (installed) cooling capacity of chillers, which provides the maximum rate of reduction in fuel consumption by the power plant and the increment in the annual cooling capacity generation following the installed cooling capacity of chillers. The efficiency of air conditioning systems was analyzed for different climatic conditions: a temperate climate using the example of Voznesensk city (Ukraine) and the subtropical climate of Nanjing city (China). It is shown that the design cooling capacity values calculated by both indicators of its use efficiency are the same for the same climatic conditions. Wherein, if to determine the design cooling capacity by both methods - by the maximum annual value and the maximum rate of growth of the indicator, its values turned out to be quite close for tropical climatic conditions and somewhat different for a temperate climate.

scholarly journals Alternative Air-Conditioning Options for Developing Countries

2017 ◽  
Vol 2 (1) ◽  
pp. 76 ◽  
Author(s):  
Muhammad Kashif ◽  
Muhammad Sultan ◽  
Zahid Mahmood Khan
Keyword(s):  
Developing Countries ◽  
Air Conditioning ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Ambient Air ◽  
Climatic Conditions ◽  
Individual Characteristics ◽  
Coefficient Of Performance ◽  
Air Conditioning System ◽  
Evaporative Cooling System

This study assesses the potential selection of efficient air-conditioning (AC) and cooling systems in order to avoid excess power consumption, mitigation of harmful refrigerants generated by the existing AC systems. Several varieties of active and passive air-conditioning systems i.e. heating ventilating air-conditioning (HVAC), vapor compression air-conditioning (VCAC) conventional direct evaporative cooling (DEC) and indirect evaporative cooling (IEC)  and desiccant air-conditioning (DAC) systems are under practice for the cooling and dehumidification. The storage of agricultural products mainly based on product individual characteristics i.e. respiration rate, transpiration rate and moisture content of that product. Variant ambient air conditions and the type of application are the main parameters for the choice of air-conditioning system to get optimum performance. The DAC system subsidize the coefficient of performance (COP) in humid regions, coastal ranges of developing countries e.g. Karachi and Gawadar (Pakistan) with hot humid climatic conditions. In similar way, hottest regions of the country such as Sibbi, Jacobabad and Multan perform better results when incorporates with M-cycle evaporative cooling system. Variation in ambient air conditions directly affect the cooling load and the choice of sustainable air-conditioning system

scholarly journals Experimental Investigation of Desiccant Dehumidification Cooling System for Climatic Conditions of Multan (Pakistan)

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5530
Author(s):  
Muhammad Aleem ◽  
Ghulam Hussain ◽  
Muhammad Sultan ◽  
Takahiko Miyazaki ◽  
Muhammad H. Mahmood ◽  
...  
Keyword(s):  
Experimental Data ◽  
Silica Gel ◽  
Air Conditioning ◽  
Ambient Air ◽  
Climatic Conditions ◽  
Coefficient Of Performance ◽  
Thermal Coefficient ◽  
Polymeric Sorbent ◽  
Experimental Apparatus ◽  
Desiccant Material

In this study, experimental apparatus of desiccant dehumidification was developed at lab-scale, using silica gel as a desiccant material. Experimental data were obtained at various ambient air conditions, while focusing the climatic conditions of Multan (Pakistan). A steady-state analysis approach for the desiccant dehumidification process was used, and thereby the slope of desiccant dehumidification line on psychrometric chart (ϕ*) was determined. It has been found that ϕ* = 0.22 in case of silica gel which is lower than the hydrophilic polymeric sorbent, i.e., ϕ* = 0.31. The study proposed two kinds of systems, i.e., (i) standalone desiccant air-conditioning (DAC) and (ii) Maisotsenko-cycle-assisted desiccant air-conditioning (M-DAC) systems. In addition, two kinds of desiccant material (i.e., silica gel and hydrophilic polymeric sorbent) were investigated from the thermodynamic point of view for both system types, using the experimental data and associated results. The study aimed to determine the optimum air-conditioning (AC) system type, as well as adsorbent material for building AC application. In this regard, perspectives of dehumidification capacity, cooling capacity, and thermal coefficient of performance (COP) are taken into consideration. According to the results, hydrophilic polymeric sorbent gave a higher performance, as compared to silica gel. In case of both systems, the performance was improved with the addition of Maisotsenko cycle evaporative cooling unit. The maximum thermal COP was achieved by using a polymer-based M-DAC system, i.e., 0.47 at 70 °C regeneration temperature.

scholarly journals МЕТОД ВИЗНАЧЕННЯ ХОЛОДОПРОДУКТИВНОСТІ УСТАНОВОК КОНДИЦІЮВАННЯ ПОВІТРЯ КОМФОРТНОГО Й ЕНЕРГЕТИЧНОГО ПРИЗНАЧЕННЯ

2019 ◽  
pp. 53-58
Author(s):  
Євген Іванович Трушляков ◽  
Андрій Миколайович Радченко ◽  
Ян Зонмін ◽  
Анатолій Анатолійович Зубарєв ◽  
Веніамін Сергійович Ткаченко
Keyword(s):  
Fuel Consumption ◽  
Air Conditioning ◽  
Mechanical Energy ◽  
Heat Engine ◽  
Ambient Air ◽  
Cooling Capacity ◽  
Climatic Conditions ◽  
High Rate ◽  
Air Cooling ◽  
Duration Of Operation

The efficiency of applying air conditioning units for comfort and energetics for a certain period, as well as any power plant, is determined by the effect obtained, primarily in the form of reducing fuel consumption over the year or increasing the production of electrical (mechanical) energy in the case of air conditioning at the heat engine inlet and by annual cold production as an indicator of the efficiency of using the cooling capacity of comfort air-conditioning plants. Since in both cases the effect depends on the duration and depth of cooling, it is quite justified to estimate it in the first approximation by the thermal hourly potential, which is the result of summation hour by hour of air temperature drops multiplied by duration of operation at a lowered temperature and, thus, takes into account current climatic conditions. Obviously, the realization of the cooling potential (air conditioning) of the ambient air depends on the installed (design) cooling capacity of the air conditioning units, which, in turn, must take into account the fluctuations in thermal loads in accordance with the current variable thermal and humidity parameters of the ambient air. Based on the different rates of the increment of the annual thermal hourly cooling potential with an increase in the installed cooling capacity of the air conditioning unit due to a change in the heat load in accordance with current climatic conditions during the year, it is necessary to choose such a design thermal load on the air conditioning unit (its installed cooling capacity) that ensures maximum or close to it the annual thermo-hour cooling potential at a relatively high rate of its increment, respectively, and the effect of cooling in the form of a decrease in fuel consumption per year in the case of air conditioning at the inlet of heat engine and annual cold production of comfort air conditioning units. It is shown that under the same climatic conditions during the year and the depth of ambient air cooling, the rational values of the design cooling capacity of air conditioning units for comfort and energy purposes are the same.

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