scholarly journals Effect of Different Plenum-Chamber Coefficients on the Frosting of Air-Cooler

Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 422
Author(s):  
Bin Liu ◽  
Shengqiang Shi ◽  
Yongshan Liu ◽  
Rachid Bennacer ◽  
Aiqiang Chen ◽  
...  

The performance of the air-cooler in refrigeration systems plays a key role in their energy efficiency. Here, the plenum-chamber coefficient was defined to investigate a possible way of enhancing the refrigeration coefficient that reflects the efficiency of the system. To investigate the influence of the plenum-chamber coefficient on the frosting and the cooling system of the air-cooler, three plenum-chamber coefficients (0.74, 0.97, 1.2) were studied under two different relative humidities. The temperature decreasing curve of the environmental chamber, the velocity distribution of the air-cooler, and the frost accumulation under and on the air-cooler were analyzed. We find that the homogeneity of the velocity distribution of the air-cooler and the frost accumulation increase with a growing plenum-chamber coefficient, while the frost accumulation on the fin will first increase and then decrease with the increase in the plenum-chamber coefficient. In general, frosting is more present when the plenum-chamber coefficient is 0.97.

2021 ◽  
Vol 321 ◽  
pp. 04019
Author(s):  
Bin Liu ◽  
Shengqiang Shi ◽  
Yongshan Liu ◽  
Rachid Bennacer ◽  
Aiqiang Chen ◽  
...  

The performance of the air-cooler in the refrigeration system plays a key role in improving the energy efficiency. Here, the plenum chamber coefficient was defined to study a possible way of enhancing the refrigeration system performance. In order to investigate the influence of the plenum chamber coefficient on the frosting and the cooling system of the chillers, three plenum chamber coefficients (0.74,0.97,1.2) were studied under high humidity. The temperature decreasing curve of the environmental chamber, the velocity distribution of the air cooler, and the frost accumulation under and on the air-cooler were analysed. The results show that the frost accumulation on the tube will increase with the increase of the plenum chamber coefficient and the frost accumulation on the fin will increase at first and then decrease with the increase of the plenum chamber coefficient. On the whole, in this study, frosting is the most obvious when the plenum chamber coefficient was 0.97


2020 ◽  
Author(s):  
A. P. Tsoy ◽  
A. V. Baranenko ◽  
A. S. Granovsky ◽  
D. A. Tsoy ◽  
R. A. Dzhamasheva

2019 ◽  
Vol 2019 (3) ◽  
pp. 249-255
Author(s):  
N Usmonov ◽  
◽  
Sh Sanayev ◽  
Z Yusupov

The article describes the developed mathematical model, algorithm and program for calculating the process of cooling the water leaving the evaporative cooler and the final temperature of humid air. The compilation of a mathematical model is based on the analysis of literature data. Practically at all industrial enterprises, technological equipment is cooled by means of circulating water supply systems equipped with evaporative coolers. The article made a choice of a cooling system for air conditioning systems of residential premises. The developed basic design scheme of the evaporative water and air cooler with the irrigated layer is presented, as well as the estimated thermal and material balance. One of the main elements of these devices is a heat-mass transfer nozzle - sprinkler. This article presents the results of mathematical modeling of processes occurring in the volume of the sprinkler evaporator chamber, Raschig rings composed of vertical polymeric materials. Expressions are obtained for determining the values of air temperature based on the calculation of thermal modeling of the process of cooling circulating water in evaporative coolers of the type in question.


2018 ◽  
pp. 39-44
Author(s):  
Богдан Сергійович Портной ◽  
Андрій Миколайович Радченко ◽  
Роман Миколайович Радченко ◽  
Сергій Анатолійович Кантор

The processes of air cooling at the gas turbine unit inlet by absorption lithium-bromide chiller have been analyzed. The computer programs of firms-producers of heat exchangers were used for the gas turbine unit inlet air cooling processes simulation. The absorption lithium-bromide chiller refrigeration capacity reserve (the design heat load excess over the current heat loads) generated at the reduced current heat loads on the air coolers at the gas turbine unit inlet in accordance with the lowered ambient air parameters has been considered. The absorption lithium-bromide chiller refrigeration capacity reserve is expedient to use at increased heat load on the air cooler. To solve this problem the refrigeration capacity required for cooling air at the gas turbine unit inlet has been compared with the excessive absorption lithium-bromide chiller refrigeration capacity exceeding current heat loads during July 2017.The scheme of gas turbine unit inlet air cooling system with using the absorption lithium-bromide chiller refrigeration capacity reserve has been proposed. The proposed air cooling system provides gas turbine unit inlet air precooling in the air cooler booster stage by using the absorption lithium-bromide chiller excessive refrigeration capacity. The absorption chiller excessive refrigeration capacity generated during decreased heat loads on the gas turbine unit inlet air cooler is accumulated in the thermal storage. The results of simulation show the expediency of the gas turbine unit inlet air cooling by using the absorption lithium-bromide chiller refrigeration capacity reserve, which is generated at reduced thermal loads, for the air precooling in the air cooler booster stage. This solution provides the absorption lithium-bromide chiller installed (designed) refrigeration capacity and cost reduction by almost 30%. The solution to increase the efficiency of gas turbine unit inlet air cooling through using the absorption chiller excessive refrigeration potential accumulated in the thermal storage has been proposed.


Author(s):  
Hidefumi Araki ◽  
Shinichi Higuchi ◽  
Shinya Marushima ◽  
Shigeo Hatamiya

The AHAT (advanced humid air turbine) system, which can be equipped with a heavy-duty, single-shaft gas turbine, aims at high efficiency equal to that of the HAT system. Instead of an intercooler, a WAC (water atomization cooling) system is used to reduce compressor work. The characteristics of a humidification tower (a saturator), which is used as a humidifier for the AHAT system, were studied. The required packing height and the exit water temperature from the humidification tower were analyzed for five virtual gas turbine systems with different capacities (1MW, 3.2MW, 10MW, 32MW and 100MW) and pressure ratios (π = 8, 12, 16, 20 and 24). Thermal efficiency of the system was compared with that of a simple cycle and a recuperative cycle with and without the WAC system. When the packing height of the humidification tower was changed, the required size varied for the three heat exchangers around the humidification tower (a recuperator, an economizer and an air cooler). The packing height with which the sum total of the size of the packing and these heat exchangers became a minimum was 1m for the lowest pressure ratio case, and 6m for the highest pressure ratio case.


Author(s):  
Arsine Baghdasarian ◽  
Omar Ramos ◽  
Jesse Ruvalcaba ◽  
Sergio Talome ◽  
Frank Wang ◽  
...  

This paper reports on the development of a conceptual design, construction and instrumentation of an experimental facility that can be used to carry out experimental research towards increasing energy efficiency in buildings. The overarching idea is to construct a system that emulates the scaled dimensions and materials of a typical building structure. The sub-scale testbed consists of a two-floor building configuration with dimensions of 1.2 m × 0.92 m × 1.1 m. The building structure is made out of wood, and covered with drywall and fiberglass insulation. Fixed walls are selected for the first floor whereas movable walls are incorporated into the second floor to study the effects of different room configurations. Four staircase openings enable airflow between the two floors. The second floor has a tiled-style ceiling and removable walls that allow for connectivity of sensors and actuators. A set of heating and cooling sub-systems, consisting of light bulbs and thermoelectric coolers connected to fans, are used for each room in the building. Both the set of light bulbs as well as the cooling system are powered through a relay box, and connected to a computer via LabVIEW which also interfaces the different sensing and actuating devices. The capabilities of the experimental facility are tested by implementing time-dependent heating- and cooling-processes and an on-off control strategy on a two-room prototype. Preliminary results demonstrate that the experimental testbed offers a reliable and versatile experimental system for research purposes.


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