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.

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.

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.

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.

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 Dryout avoidance control for multi-evaporator vapor compression cycle cooling

2015 ◽  
Vol 160 ◽  
pp. 266-285 ◽  
Author(s):  
Daniel T. Pollock ◽  
Zehao Yang ◽  
John T. Wen
Keyword(s):  
Vapor Compression ◽  
Vapor Compression Cycle ◽  
Compression Cycle ◽  
Avoidance Control

Performance evaluation of a combined ejector-vapor compression cycle

2013 ◽  
Vol 55 ◽  
pp. 331-337 ◽  
Author(s):  
Jia Yan ◽  
Wenjian Cai ◽  
Lei Zhao ◽  
Yanzhong Li ◽  
Chen Lin
Keyword(s):  
Performance Evaluation ◽  
Vapor Compression ◽  
Vapor Compression Cycle ◽  
Compression Cycle
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