Cooling Systems for Refuge Alternatives in Hot Mine Conditions

2018 ◽  
Author(s):  
Lincan Yan ◽  
David Yantek ◽  
Miguel Reyes ◽  
Nicholas Damiano ◽  
Justin Srednicki ◽  
...  
Keyword(s):  
Air Temperature ◽  
Elevated Temperatures ◽  
Storage Capacity ◽  
Cooling System ◽  
Cooling Capacity ◽  
Cooling Systems ◽  
Air Conditioning System ◽  
Test Methodology ◽  
Air Supply ◽  
Entire Duration

The accumulated heat and humidity inside occupied refuge alternatives (RAs) can impose risk of heat stress to the occupants. The accumulated heat could be from the metabolic and environmental sources. For hot mines, the high ambient temperature makes it more difficult to dissipate heat accumulated inside the RA. A cooling system is then needed to reduce the interior heat and humidity. Two types of cooling systems were tested out for their cooling capacity. One cooling system is a portable, battery-powered, air conditioning system and the other is a portable cryogenic air supply. During the testing, the mine air temperature surrounding the RA was elevated to and maintained at 85°F to simulate hot mine environment. The tests demonstrated that both cooling systems were able to control the air temperature inside the RA even though they did not last the entire duration of a 96-hour test. This paper provides an overview of the test methodology and findings as well as guidance on improving the performance of both cooling systems, including: optimizing the cooling cycle for the battery-powered AC system and increasing the flow rate and tank storage capacity for the cryogenic system. The information in this publication is useful for RA manufacturers and mines to develop the cooling systems that will enable providing the life sustaining environment in mines with elevated temperatures.

Rechargeable Personal Air Conditioning Device

2016 ◽  
Author(s):  
Yilin Du ◽  
Jan Muehlbauer ◽  
Jiazhen Ling ◽  
Vikrant Aute ◽  
Yunho Hwang ◽  
...  
Keyword(s):  
Air Conditioning ◽  
Cooling System ◽  
Cooling Capacity ◽  
Comfort Level ◽  
Vapor Compression ◽  
Air Conditioning System ◽  
System A ◽  
Single Person ◽  
Vapor Compression Cycle ◽  
Compression Cycle

A rechargeable personal air-conditioning (RPAC) device was developed to provide an improved thermal comfort level for individuals in inadequately cooled environments. This device is a battery powered air-conditioning system with the phase change material (PCM) for heat storage. The condenser heat is stored in the PCM during the cooling operation and is discharged while the battery is charged by using the vapor compression cycle as a thermosiphon loop. The conditioned air is discharged towards a single person through adjustable nozzle. The main focus of the current research was on the development of the cooling system. A 100 W cooling capacity prototype was designed, built, and tested. The cooling capacity of the vapor compression cycle measured was 165.6 W. The PCM was recharged in nearly 8 hours under thermosiphon mode. When this device is used in the controlled built environment, the thermostat setting can be increased so that building air conditioning energy can be saved by about 5–10%.

scholarly journals Experimental Study to Performance Improvement of Vapor Compression Cooling System Integrated Direct Evaporative Cooler and Condenser

2018 ◽  
Vol 215 ◽  
pp. 01017
Author(s):  
Arfidian Rachman ◽  
Lisa Nesti
Keyword(s):  
Energy Use ◽  
Cooling System ◽  
Electricity Consumption ◽  
Weather Condition ◽  
Heat Removal ◽  
Cooling Capacity ◽  
Cooling Power ◽  
Cooling Systems ◽  
Evaporative Cooler ◽  
And Performance

For areas with very hot and humid weather condition increased latent and sensible load are a major problem in cooling systems that will increase compressor work so that electricity consumption will also increase. Combined condenser with direct evaporate cooling will increase the heat removal process by using an evaporative cooler effect that will increase the efficiency of energy use. This paper presents the study of the use of evaporator cooling and condenser. This paper mainly calculated energy consumption in steam compression cooling systems and related problems. From the results of this study, the use of condensers with evaporative cooling, power consumption can be reduced to 46% and performance coefficient (COP) can be increased by about 12%, with 1,2 kW cooling capacity.

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
Keyword(s):  
Gas Turbines ◽  
Maximum Rate ◽  
Cooling System ◽  
Ambient Air ◽  
Cooling Capacity ◽  
Climatic Conditions ◽  
Air Cooling ◽  
Thermal Loads ◽  
Cooling Systems ◽  
Air Cooling System

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.).

Theoretical analysis of heat and mass transfer processes in an evaporative cooling system with zeolite desiccant powered by solar energy

2018 ◽  
Author(s):  
◽  
Amged Al Ezzi
Keyword(s):  
Water Vapor ◽  
Flat Plate ◽  
Air Temperature ◽  
Air Conditioning ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Air Conditioning System ◽  
Coating Method ◽  
Evaporative Cooler ◽  
Desiccant Material

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Concerns about energy sources depletion and environmental pollution issues have been raised and is a top priority of the global community. Refrigeration machines have been received the major of attention because of their energy consumption and pollution. Different from traditional cooling strategies, desiccant cooling technology (DCT) has been emergent as a promising alternative giving the fact that the economic-ecological air conditioning system is not restricted to hot and dry climates only. In the current experimental study, an advancement solar assisted desiccant cooling system (SADCS) is presented. The advantage is to use only a fraction of the energy of typical compressor-based cooling systems. The advancements have taken place into the dehumidification, evaporator, and regeneration sections. The role of appropriate choosing of the desiccant material type on the adsorption process has been presented, and a Faujasite (FAU) 13X zeolite is utilized in the dehumidification stage. A novel monolayer coating method has conducted. The new coating method has insured no external water vapor condensation ruins the desiccant material during relative humidity working range (20-97) %. Moreover, the new coating method allows to increase the performance of the adsorption and desorption processes, respectively. By giving the coming air stream the ability to pass through and surround the zeolite beads, accessibility to adsorb and desorb water vapor molecules is easier as more rooms are available. That clearly has been stated as 6450 g of zeolite holds 684 g of water in full saturation status within 37 minutes and regenerates by less than 120 [degree]C air temperature within 66 minutes. In the evaporative cooling section, an effective small compact evaporative cooler (CEC) system dealing only with product flow is introduced. The new CEC is utilized direct and indirect evaporation of water mechanisms combined in cross channels to cool air. Dropping air temperature by (5-7) [degree]C has recorded without desiccant stage. Supplying the required regeneration energy from a green energy source was essential in this study. For this purpose, an innovative flat plate double-mesh air solar collector has designed and carried out. In the new collector, a double copper mesh frames were fixing within a double Plexiglas covers flat plate collector. Experimental results show a good consistent with the mathematical model. With an average 0.71 solar fraction and 80 [degree]C exit air temperature, the collector presents 0.73 as thermal efficiency. As the improvements of the desiccant air-conditioning system turns out globally recognized by the progress in different research outcomes, designs, setting up and evaluation methods, it is expected that the system will be one of the most important alternative systems for the maintenance of human's environment comfort and air quality when considering the reduced dependence on conventional energy usage. Present work and results provide a reference data sets related to real adsorption dehumidification process and show that the advancement SADCS has a great potential in the future of the evaporative cooler systems.

scholarly journals Energy-focused substantiation of the choice of an air conditioning system for an office and shopping building

2021 ◽  
Vol 11 (2) ◽  
pp. 38-45
Author(s):  
Anastasiya A. Frolova ◽  
◽  
Pavel I. Lukhmenev ◽  
Keyword(s):  
Power Consumption ◽  
Air Conditioning ◽  
Large Scale ◽  
Cooling System ◽  
Air Cooling ◽  
Outdoor Temperature ◽  
Cooling Systems ◽  
Air Conditioning System ◽  
Northern Areas ◽  
Conventional Cooling

Introduction. The air conditioning system is the main consumer of electricity inside office and shopping buildings. The coo­ling needs arise inside such buildings all over the year due to high amounts of heat emitted by people and equipment (computers, office equipment, cash registers), solar radiation (the envelopes of the majority of these buildings have continuous glazed facades) and sources of artificial lighting. A conventional cooling system has a compressor and condensers. The most important step towards an optimized and low-energy cooling system is the abandonment of compressor and condensers; in addition, the cold extracted from the outdoor air, is used in the system. This cooling technique is called an atmospheric co­oling system. The climatic features of Russia allow for a large-scale application of the cooling technology that uses natural cold. However, for a start, a decision was made to focus on a central region of the Russian Federation, namely, Moscow, rather than any northern areas of the country. Materials and methods. The problem is solved by the calculation method applied to the case of a 35-storey office building in Moscow. Various outdoor temperature options were considered as the bases for a transition to an atmospheric cooling system. The co-authors also compare different installation options for dry coolers, which in turn affect the routing length of refrigeration circuits. The annual demand for cold is calculated for all analyzed options. Results. Some results are presented in the form of tables of annual energy consumption by different types of air cooling systems. Conclusions. The co-authors have found that the location of dry coolers strongly affects the power consumption by a co­oling system. Power consumption by cooling systems was analyzed, and it was found out that transition to machine refrigeration at the higher outdoor temperature of +8 °C is more efficient from the standpoint of energy efficiency than the same transition at +5 and 0 °C.

scholarly journals АНАЛІЗ ЕФЕКТИВНОСТІ ОХОЛОДЖЕННЯ ПОВІТРЯ КОГЕНЕРАЦІЙНОГО ГАЗОПОРШНЕВОГО МОДУЛЯ УСТАНОВКИ АВТОНОМНОГО ЕНЕРГОЗАБЕЗПЕЧЕННЯ

2019 ◽  
pp. 76-80
Author(s):  
Андрій Миколайович Радченко ◽  
Анатолій Анатолійович Зубарєв ◽  
Сергій Георгійович Фордуй ◽  
Володимир Володимирович Бойчук ◽  
Віталій Васильович Цуцман
Keyword(s):  
Air Temperature ◽  
Elevated Temperatures ◽  
Cooling System ◽  
Electric Energy ◽  
Ambient Air ◽  
Hot Water ◽  
Lubricating Oil ◽  
Air Cooling ◽  
Air Conditioner ◽  
Engine Room

The analysis of the efficiency of cooling air of cogeneration gas-piston module of installations for combined production of electric energy, heat, and cold is performed. The installation for energy supply includes two JMS 420 GS-N.LC GE Jenbacher cogeneration gas-piston engines manufactured as cogeneration modules with heat exchangers for removing the heat of exhaust gases, scavenge gas-air mixture, cooling water of engine and lubricating oil. The heat of hot water is transformed by the absorption lithium-bromide chiller AR-D500L2 Century into the cold, which is spent on technological needs and for the operation of the central air conditioner for cooling the incoming air of the engine room, wherefrom it is sucked by the turbocharger of the engine. The temperature of the scavenge gas-air mixture at the entrance to the working cylinders of the engine is maintained by the system of recirculating cooling with the removal of its heat into surroundings by the radiator. Because of significant heat influx from working engines and other equipment, as well as through the enclosures of the engine room from the outside to the air-cooled in the central air conditioner in the engine room, from where it is sucked by a turbocharger, the air temperature at the inlet of the turbocharger is quite high: 25...30 °C. At elevated temperatures of the ambient air at the inlet of the radiator for cooling scavenge gas-air mixture and the air at the turbocharger inlet the fuel economy of engine is falling, which indicates the need for efficient cooling of air. The efficiency of cooling the air of the gas-piston module was estimated by a reduction in the consumption of gaseous fuel and the increase in electric power of the engine. For this purpose, the data of monitoring on the fuel efficiency of the gas-piston engine with the combined influence of the ambient air temperature at the inlet of the radiator and the air at the turbocharger inlet were processed to obtain data on their separate effects and to determine the ways to further improve the air cooling system of the gas-piston module.

scholarly journals Evaporative Cooling Integrated with Solid Desiccant Systems: A Review

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5982
Author(s):  
Lanbo Lai ◽  
Xiaolin Wang ◽  
Gholamreza Kefayati ◽  
Eric Hu
Keyword(s):  
Air Temperature ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Operating Cost ◽  
Weather Conditions ◽  
Dew Point ◽  
Air Conditioning System ◽  
Direct Evaporative Cooling ◽  
Dry Climates ◽  
Desiccant Material

Evaporative cooling technology (ECT) has been deemed as an alternative to the conventional vapor-compression air conditioning system for dry climates in recent years due to its simple structure and low operating cost. Generally speaking, the ECT includes two types of different technologies, direct evaporative cooling (DEC) and indirect evaporative cooling (IEC). Both technologies can theoretically reduce the air temperature to the wet-bulb temperature of outdoor air. The major difference between these two technologies is that DEC will introduce extra moisture to the supply air while IEC will not. The enhanced IEC, Maisotsenko-cycle (M-cyle) IEC, can even bring down the air temperature to the dew point temperature. The ECT integrated with solid desiccant systems, i.e., solid desiccant-assisted evaporative cooling technologies (SDECT), could make the technology applicable to a wider range of weather conditions, e.g., weather with high humidity. In this paper, the recent development of various evaporative cooling technologies (ECT), solid desiccant material and the integration of these two technologies, the SDECT, were thoroughly reviewed with respect to their configuration, optimization and desiccant unit improvement. Furthermore, modeling techniques for simulating SDECT with their pros and cons were also reviewed. Potential opportunities and research recommendations were indicated, which include improving the structure and material of M-cycle IEC, developing novel desiccant material and optimizing configuration, water consumption rate and operation strategy of SDECT system. This review paper indicated that the SDECT system could be a potential replacement for the conventional vapor-compressed cooling system and could be applied in hot and humid environments with proper arrangements.

scholarly journals RESULTS OF INSPECTION OF THE STATE OF PROVIDING THE MICROCLIMATE IN THE PIG FARM WITH A NEGATIVE PRESSURE VENTILATION SYSTEM

2021 ◽  
pp. 168-177
Author(s):  
Vitalii Yaropud ◽  
Yelchin Aliyev
Keyword(s):  
Air Temperature ◽  
Negative Pressure ◽  
Cooling System ◽  
Ventilation System ◽  
Air Cooling ◽  
Negative Pressure Ventilation ◽  
Normal Limits ◽  
Air Supply ◽  
Air Cooling System ◽  
Pig Farm

The most popular microclimate system today is based on a negative pressure ventilation system. Because it is easier to use and consumes less energy than any other forced ventilation system. The purpose of the research is to inspect the room for keeping piglets on rearing with a negative pressure ventilation system to identify shortcomings and deviations of the microclimate parameters necessary for further improvement. According to the results of the inspection of the rearing room for piglets, it was found that according to the existing system of negative pressure in the rearing room for piglets, most indicators (air velocity, ammonia, carbon dioxide, hydrogen sulfide, oxygen) are within normal limits. According to the results of the inspection of the room for keeping piglets for rearing with a negative pressure microclimate system, it was found that the air temperature in the room does not meet the recommended limits and reaches 30 °C, while the maximum recommended temperature for piglets for fattening is 20 °C. The air temperature is uneven along the length of the room, which is caused by uneven air supply from the vents. According to the results of the inspection of the room for piglets with a negative pressure microclimate system, it was found that the relative humidity at the height of the animals is higher than the recommended norms and reaches 95%, while the recommended humidity for piglets for fattening is not more than 80%. According to the results of the inspection of the room for keeping piglets for rearing with a negative pressure microclimate system, it can be stated that it is necessary to improve the air cooling system and replan the ventilation ducts of the ventilation system to ensure even air flow.

Long axis heat distribution in a tunnel-ventilated broiler house equipped with an evaporative pad cooling system

2009 ◽  
Vol 49 (12) ◽  
pp. 1125 ◽  
Author(s):  
M. Dağtekin ◽  
C. Karaca ◽  
Y. Yildiz
Keyword(s):  
High Temperatures ◽  
Air Temperature ◽  
Egg Production ◽  
Cooling System ◽  
Heat Distribution ◽  
Exit Point ◽  
Cooling Efficiency ◽  
Cooling Systems ◽  
Southern Turkey ◽  
Broiler House

Chicken meat and egg production in the Çukurova region of Southern Turkey shows enormous potential for growth. However, high temperatures in summer pose serious difficulties for these types of production. Evaporative pad cooling systems have been used to minimise rises in temperature and are commonly used in poultry houses in this region. The change of air temperature from the entry point to the system through the pads, to the exit point of the broiler house was investigated in this study. Experiments were carried out in a tunnel-ventilated broiler house in the Çukurova region. The broiler house has the capacity to house 15 000 chicks with a floor area of 70 by 12 m. In this experiment, the broiler house incorporated 15-cm-thick cellulose-based pads. Results obtained in August–September 2007 revealed a cooling efficiency of 69.35%, a 5.19°C decrease from the outside air temperature after passing through the pads, and a 1.52°C increase in air temperature at the exit point, which was located at the end of the broiler house.

Desiccant Degradation in Desiccant Cooling Systems: A System Study

1993 ◽  
Vol 115 (4) ◽  
pp. 237-240 ◽  
Author(s):  
A. A. Pesaran
Keyword(s):  
Cooling System ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Thermal Coefficient ◽  
Ventilation Mode ◽  
Worst Case ◽  
Cooling Systems ◽  
Degradation Data ◽  
Percent Loss ◽  
The Impact

We predicted the impact of desiccant degradation on the performance of an open-cycle desiccant cooling system in ventilation mode using the degradation data on silica gel obtained from a previous study. The degradation data were based on thermal cycling desiccant samples and exposing them to ambient or contaminated air. Depending on the degree of desiccant degradation, the decrease in the thermal coefficient of performance (COP) and the cooling capacity of the system for low-temperature regeneration was 10 percent to 35 percent. The 35 percent loss occurred based on the worst-case desiccant degradation scenario. Under more realistic conditions the loss in system performance is expected to be lower.

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