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 KAJI PERFORMANSI REFRIGERAN R-290, R-32, DAN R-410A SEBAGAI ALTERNATIF PENGGANTI R-22

2021 ◽  
Vol 4 ◽  
pp. 133-139
Author(s):  
Rikhard Ufie ◽  
Cendy S. Tupamahu ◽  
Sefnath J. E. Sarwuna ◽  
Jufraet Frans
Keyword(s):  
Air Conditioning ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Condensation Temperature ◽  
Vapor Compression ◽  
Know How ◽  
Evaporation Temperature ◽  
Vapor Compression Cycle ◽  
Compression Cycle ◽  
Refrigeration Capacity

Refrigerant R-22 is a substance that destroys the ozone layer, so that in the field of air conditioning it has begun to be replaced, among others with refrigerants R-32 and R-410a, and also R-290. Through this research, we want to know how much Coefficient of Performance (COP) and Refrigeration Capacity (Qe) can be produced for the four types of refrigerants. The study was carried out theoretically for the working conditions of the vapor compression cycle with an evaporation temperature (Tevap) of 0, -5, and -10oC, a further heated refrigerant temperature (ΔTSH) of 5 oC, a condensation temperature (Tkond) of 45 oC and a low-cold refrigerant temperature. (ΔTSC) 10 oC and compression power of 1 PK . The results of the study show that the Coefficient of Performance (COP) in the use of R-22 and R-290 is higher than the use of R-32 and R-410a, which are 4,920 respectively; 4,891; 4.690 and 4.409 when working at an evaporation temperature of 0 oC; 4.260; 4,234; 4.060 and 3.812 when working at an evaporation temperature of -5 oC; and amounted to 3,730; 3,685; 3,550 and 3,324 if working at an evaporation temperature of -10 oC. Based on the size of the COP, if this installation works with a compression power of 1 PK, then the cooling capacity of the R-22 and R-290 is higher than the R-32 and R-410a, which are 3,617 respectively. kW; 3,597 kW; 3,449 kW and 3,243 kW. If working at an evaporation temperature of 0 oC; 3.133 kW; 3.114 kW; 2,986 kW and 2,804 kW if working at an evaporation temperature of -5 oC; and 2,741 kW; 2,710 kW; 2,611 kW and 2,445 kW if working at an evaporation temperature of -10oC.

Air conditioning systems for aeronautical applications: a review

2019 ◽  
Vol 124 (1274) ◽  
pp. 499-532
Author(s):  
M. Merzvinskas ◽  
C. Bringhenti ◽  
J.T. Tomita ◽  
C.R. de Andrade
Keyword(s):  
Air Conditioning ◽  
Environmental Control ◽  
Cooling Capacity ◽  
Vapor Compression ◽  
Water Separation ◽  
Technological Advances ◽  
Vapor Compression Cycle ◽  
Compression Cycle ◽  
Air Conditioning Systems ◽  
Aircraft Conceptual Design

ABSTRACTThis paper presents a review of the various aeronautical air conditioning systems that are currently available and discusses possible system configurations in the context of the aeronautical environmental control systems. Descriptions of the standard vapor compression cycle and air cycles are provided. The latter includes, simple-cycle, bootstrap-cycle, simple-bootstrap cycle (3-wheel) and condensing cycle (4-wheel). Water separation and air recirculation systems are also explored. A comparison between vapor compression cycles and air cycles is provided, as well as a comparison between different air cycles. Air cycle units are far less efficient than vapor compression cycle units, but they are lighter and more reliable for an equivalent cooling capacity. Details regarding the aircraft conceptual design phase along with general criteria for the selection of an air conditioning system are provided. Additionally, industry trends and technological advances are examined. Conclusions are compiled to guide the systems engineer in the search for the most appropriate design for a particular application.

Performance Prediction of Electroosmotic Dehumidification

2009 ◽  
Author(s):  
David W. Gerlach
Keyword(s):  
Air Conditioning ◽  
Airflow Rate ◽  
Air Conditioner ◽  
Vapor Compression ◽  
Air Conditioning System ◽  
Vapor Compression Cycle ◽  
Compression Cycle ◽  
In Series ◽  
Vapor Compression System ◽  
Air Conditioning Systems

In electroosmotic dehumidification (EOD), a membrane composed of a desiccant material removes moisture from air to be conditioned. Then the water is pumped through pores in the membrane by the application of a voltage and rejected on the other side. This allows the sensible and latent loads in air conditioning to be handled separately and may lead to improvements in energy efficiency and comfort control. The performance of an air conditioning system using an electroosmotic dehumidification system in series with a conventional vapor compression cycle was modeled. The electroosmotic system handles the entire latent load and the vapor compression system handles the entire sensible cooling load. Performance of the system was compared to a conventional vapor compression air conditioner that handles both the latent and sensible loads with a single evaporator coil. Literature data for Nafion membranes was used in a simple electroosmotic drag model. Modeling indicates the feasibility of electroosmotic dehumidification for separating the control of latent and sensible load in air conditioning systems. The total COP of the system, neglecting fan power, can be 1–2 times higher (depending on airflow rate) than a system using an evaporator for latent and sensible load.

The Steady-State Modeling and Analysis of a Two-Loop Cooling System for High Heat Flux Removal

2009 ◽  
Author(s):  
Rongliang Zhou ◽  
Juan Catano ◽  
Tiejun Zhang ◽  
John T. Wen ◽  
Greg J. Michna ◽  
...  
Keyword(s):  
Heat Flux ◽  
Steady State ◽  
Heat Exchangers ◽  
Cooling System ◽  
High Heat ◽  
System Structure ◽  
High Heat Flux ◽  
Vapor Compression ◽  
Vapor Compression Cycle ◽  
Compression Cycle

Steady-state modeling and analysis of a two-loop cooling system for high heat flux removal applications are studied. The system structure proposed consists of a primary pumped loop and a vapor compression cycle (VCC) as the secondary loop to which the pumped loop rejects heat. The pumped loop consists of evaporator, condenser, pump, and bladder liquid accumulator. The pumped loop evaporator has direct contact with the heat generating device and CHF must be higher than the imposed heat fluxes to prevent device burnout. The bladder liquid accumulator adjusts the pumped loop pressure level and, hence, the subcooling of the refrigerant to avoid pump cavitation and to achieve high critical heat flux (CHF) in the pumped loop evaporator. The vapor compression cycle of the two-loop cooling system consists of evaporator, liquid accumulator, compressor, condenser and electronic expansion valve. It is coupled with the pumped loop through a fluid-to-fluid heat exchanger that serves as both the vapor compression cycle evaporator and the pumped loop condenser. The liquid accumulator of the vapor compression cycle regulates the cycle active refrigerant charge and provides saturated vapor to the compressor at steady state. The heat exchangers are modeled with the mass, momentum, and energy balance equations. Due to the projected incorporation of microchannels in the pumped loop to enhance the heat transfer in heat sinks, the momentum equation, rarely seen in previous refrigeration system modeling efforts, is included to capture the expected significant microchannel pressure drop witnessed in previous experimental investigations. Electronic expansion valve, compressor, pump, and liquid accumulators are modeled as static components due to their much faster dynamics compared with heat exchangers. The steady-state model can be used for static system design that includes determining the total refrigerant charge in the vapor compression cycle and the pumped loop to accommodate the varying heat load, sizing of various components, and parametric studies to optimize the operating conditions for a given heat load. The effect of pumped loop pressure level, heat exchangers geometries, pumped loop refrigerant selection, and placement of the pump (upstream or downstream of the evaporator) are studied. The two-loop cooling system structure shows both improved coefficient of performance (COP) and CHF overthe single loop vapor compression cycle investigated earlier by authors for high heat flux removal.

scholarly journals Experimental and Theoretical Study on the Cooling Performance of a CO2 Mobile Air Conditioning System

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1927 ◽  
Author(s):  
Dandong Wang ◽  
Binbin Yu ◽  
Junye Shi ◽  
Jiangping Chen
Keyword(s):  
Air Conditioning ◽  
Theoretical Study ◽  
Cooling Capacity ◽  
Air Conditioning System ◽  
Cooling Performance ◽  
System A ◽  
Hfc 134A ◽  
Expansion Valve ◽  
The Impact ◽  
Compressor Efficiency

CO2 (GWP = 1) is considered as a promising natural alternative refrigerant to HFC-134a in mobile air conditioning (MAC) applications. The objective of this study is to investigate the cooling performance characteristics of a CO2 MAC system. A prototype CO2 MAC system, consisting of a CO2 electrical compressor, CO2 parallel flow microchannel heat exchangers, and an electrical expansion valve, was developed and tested. Factor analysis experiments were conducted to reveal the effect of outdoor temperature on the cooling performance of this CO2 MAC system. Compared with a conventional R134a MAC system, the prototype CO2 MAC system achieved comparable cooling capacity, but had COP reductions of 26% and 10% at 27 °C and 45 °C outdoor conditions, respectively. In addition, based on refrigerant properties, theoretical cycle analysis was done to reveal the impact of evaporator, gas cooler and compressor, on the system cooling performance. It is concluded that the increase of overall compressor efficiency or the decrease of gas cooler approaching temperature could greatly improve the COP of this CO2 MAC system.

scholarly journals DESIGN OF A COVID-19 RESPONSE FIELD HOSPITAL

2020 ◽  
Vol 5 (8) ◽  
Author(s):  
Trisham Bharat Patil
Keyword(s):  
Air Conditioning ◽  
Vapor Compression ◽  
Hvac System ◽  
Field Hospital ◽  
Regional Effect ◽  
Vapor Compression Cycle ◽  
Compression Cycle ◽  
Care Facilities ◽  
Response Field

This paper includes the methodology and avenues of approach involved in a comprehensive design of a Vapor Compression Cycle (VCC) for a Heating, Ventilating, and Air Conditioning (HVAC) system accommodating a mobile hospital. The development and deployment of this hospital is in response to the current global COVID-19 pandemic and its regional effect on existing local care facilities.

Review on Solar Powered Desiccant Wheel Cooling System

2017 ◽  
Vol 9 (01) ◽  
pp. 31-34
Author(s):  
Khushboo Singh
Keyword(s):  
Air Conditioning ◽  
Cooling System ◽  
Good Alternative ◽  
Energy Utilization ◽  
Working Fluid ◽  
Low Grade ◽  
Vapor Compression ◽  
Air Conditioning System ◽  
Desiccant Wheel ◽  
Solar Powered

Nowadays, there is still a big amount of needs in air conditioning system with environmental change and improvement of living standards. However, air conditioning system have already accounted for a large part of energy consumption in the whole society, and then how to effectively increase the energy utilization. Desiccant wheel cooling system operate on the principle of adsorption dehumidification and evaporate cooling. The system adopts natural substance as working fluid and can be driven by low grade thermal energy such as solar energy. Due to this merit, solar powered desiccant wheel cooling system has recognized as one of good alternative to conventional vapor compression air conditioning system and has obtained increasing interest in the past years. This review paper aims to summarize recent research development related to solar powered desiccant wheel cooling system and to provide information for potential application. The cooling potential of the system is based on the performance of the desiccant wheel that removes humidity from outside air to increase the potential of the humidifier.

Theoretical and experimental simulation of roof-top bus multiple-circuit air-conditioning system performance

2007 ◽  
Vol 221 (12) ◽  
pp. 1665-1677
Author(s):  
M Khamis Mansour ◽  
M N Musa ◽  
M N W Hassan ◽  
H Abdullah
Keyword(s):  
Experimental Data ◽  
Computer Model ◽  
Air Conditioning ◽  
Cooling Capacity ◽  
Experimental Simulation ◽  
Cooling Load ◽  
Air Conditioner ◽  
Air Conditioning System ◽  
System A ◽  
Cooling Loads

Many air-conditioning (AC) systems are designed to operate at maximum cooling capacity regardless of the variation in the daily cooling load. At low loads, the conditions can be uncomfortably cold and the overcooling is an unnecessary waste of energy. To address these two issues, a multiple refrigeration circuit concept is proposed and applied to a roof-top bus AC system. A two-circuit model is proposed for a standard bus size in which each circuit has two evaporators of equal sizes arranged in parallel and installed on each passenger row, respectively. This means that each passenger row is served by two different evaporators sharing a common heat exchanger box. Depending on the cooling load, this concept allows one or both circuits (compressor motors) to be switched on and during either modes, it also allows one or more sets of evaporator blowers to be switched on. A steady-state computer model has been developed to simulate the performance of the proposed two-circuit AC system. A two-circuit air conditioner is also designed to form a roof-top bus AC system, fabricated, and installed on to an experimental rig. The experimental data are used to validate the computer model. The validation is on the system thermal performance and on the evaporator air outlet conditions (dry bulb temperature and relative humidity) at different modes of system operation, either at full or partial cooling loads. The simulated results gave satisfactory agreement with those obtained from the experimental work. Maximum absolute deviations are within the range of 19.3 per cent, although most of the simulated results are less than a 10 per cent range from the experimental ones, which validates the computer program. The paper describes the modelling work carried out and the results obtained are presented in comparison with the experimental data.

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