Effects of operating parameters on the performance of a CO2 air conditioning system for vehicles

The present study examines the performance of a hybrid air-conditioning system in which a vapour compression inverse cycle is integrated with an air dehumidification system working with hygroscopic solution and hydrophobic membrane. This approach may prove to be a valid alternative to the traditional summertime air-conditioning system, which involves cooling the air to below its dew point and subsequently reheating it. The system examined simultaneously cools and dehumidifies the air in an air-LiCl solution membrane vapour exchanger before it enters the conditioned environment. The LiCl solution is cooled by means of a vapour compression inverse cycle that uses the refrigerant KLEA 407C. The heat rejected by the condenser is used to regenerate the solution. A SIMULINK calculation programme was used to simulate the system in steady-state conditions. The performance of the system was analysed on varying significant operating parameters and was compared with that of a traditional direct-expansion air-conditioning plant. The results of the simulations revealed significant power saving which, in certain operating conditions, was as much as 50%.

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A numerical study on the effects of design/operating parameters of the radiant panel in a radiation-based task air conditioning system on indoor thermal comfort and energy saving for a sleeping environment

Energy and Buildings ◽

10.1016/j.enbuild.2017.06.052 ◽

2017 ◽

Vol 151 ◽

pp. 250-262 ◽

Cited By ~ 16

Author(s):

Jing Du ◽

Mingyin Chan ◽

Dongmei Pan ◽

Shiming Deng

Keyword(s):

Thermal Comfort ◽

Energy Saving ◽

Air Conditioning ◽

Numerical Study ◽

Operating Parameters ◽

Air Conditioning System ◽

Indoor Thermal Comfort ◽

Radiant Panel

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Thermal energy analysis on liquid desiccant air conditioning system at different desiccant solution parameters

Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering ◽

10.1177/0954408919825721 ◽

2019 ◽

Vol 233 (5) ◽

pp. 1052-1065

Author(s):

Y Siva Kumar Reddy ◽

Karthik Balasubramanian ◽

VP Chandramohan

Keyword(s):

Heat Capacity ◽

Thermal Energy ◽

Air Conditioning ◽

Energy Analysis ◽

Operating Parameters ◽

Liquid Desiccant ◽

High Concentration ◽

Air Conditioning System ◽

Capacity Ratio ◽

Solution Parameters

Selection of suitable liquid desiccant operating parameters plays a significant role in the design of energy efficient liquid desiccant air conditioning system. To achieve same dehumidification rate from ambient air, different combinations of solution parameters (heat capacity ratio, concentration, and vapor pressure) could be employed in the system. Considering dehumidifier air inlet condition and dehumidification rates are fixed, an analytical study is carried out on the thermal energy analysis of the system at different solution operating parameters. Operating parameters considered in this study are solution concentrations ( Cs = 0.25, 0.3, 0.35 and 0.40) and heat capacity ratios ([Formula: see text] = 2.5, 3, 4 and 5). Control volume which includes a pair of air and solution channels (half width channels) of full scale liquid-to-air membrane energy exchangers (LAMEE) has been chosen to analyze the energy transfer between air and solution. The results indicate system requires lesser chiller load ( Qchiller) at high concentration and low heat capacity ratio ( Cs = 0.40 and [Formula: see text] = 2.5) which is 0.29 kW to achieve 0.61 kW cooling load. This is 99% lesser than the Qchiller at high concentration and high heat capacity ratio ( Cs = 0.40 and [Formula: see text] = 5) and 30% lesser than the Qchiller at low concentration and low heat capacity ratio ( Cs = 0.25 and [Formula: see text] = 2.5). Solution heat addition rate ( Qadd) per kW cooling capacity ( Qcc) at this solution condition is found as 0.85 kW.

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Application and analysis of carbon dioxide refrigeration system with ejector in commercial super cold cabinet

E3S Web of Conferences ◽

10.1051/e3sconf/202126702019 ◽

2021 ◽

Vol 267 ◽

pp. 02019

Author(s):

Li Guangpeng ◽

Zhou Yingli ◽

Wang Qi

Keyword(s):

System Performance ◽

Theoretical Basis ◽

Air Conditioning ◽

Measurement Method ◽

Operating Parameters ◽

Refrigeration System ◽

Design Development ◽

Air Conditioning System ◽

Large Pressure ◽

Experimental Parameters

In this paper, the transcritical CO2 refrigeration system with ejector is applied to a commercial ultra-cold cabinet. The influence of the key operating parameters of the ejector on the system performance is analyzed, and the measurement method of the experimental parameters is proposed. The results show that the ejector can eject the low pressure refrigerant into the reservoir by using the energy of the large pressure difference throttle, and the COP of the system can be increased by 9%-19%. This paper provides a theoretical basis for the design, development and optimization of CO2 refrigeration and air conditioning system with ejector.

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ANALYSIS OF COMPETING VARIANTS OF AIR CONDITIONING SYSTEMS WITHOUT AIR EXTRACTION FROM ENGINES AT THE STAGE OF PASSENGER AIRCRAFT ONBOARD SYSTEMS CONCEPTUAL DESIGN

Computational nanotechnology ◽

10.33693/2313-223x-2019-6-3-86-91 ◽

2019 ◽

Vol 6 (3) ◽

pp. 80-85

Author(s):

Denis Igorevich Smagin ◽

Konstantin Igorevich Starostin ◽

Roman Sergeevich Savelyev ◽

Anatoly Anatolyevich Satin ◽

Anastasiya Romanovna Neveshkina ◽

...

Keyword(s):

Conceptual Design ◽

Air Conditioning ◽

Research University ◽

Cooling System ◽

Fuel Efficiency ◽

Air Cooling ◽

Moscow Aviation Institute ◽

Air Conditioning System ◽

Low Efficiency ◽

Air Conditioning Systems

One of the ways to achieve safety and comfort is to improve on-board air conditioning systems.The use of air cooling machine determines the air pressure high level at the point of selection from the aircraft engine compressor. Because of the aircraft operation in different modes and especially in the modes of small gas engines, deliberately high stages of selection have to be used for ensuring proper operation of the refrigeration machine in the modes of the aircraft small gas engines. Into force of this, most modes of aircraft operation have to throttle the pressure of the selected stage of selection, which, together with the low efficiency of the air cycle cooling system, makes the currently used air conditioning systems energy inefficient.A key feature of the architecture without air extraction from the main engines compressors is the use of electric drive compressors as a source of compressed air.A comparative analysis of competing variants of on-board air conditioning system without air extraction from engines for longrange aircraft projects was performed at the Moscow Aviation Institute (National Research University).The article deals with the main approaches to the decision-making process on the appearance of a promising aircraft on-board air conditioning system at the stage of its conceptual design and formulated the basic requirements for the structure of a complex criterion at different life cycle stages.The level of technical and technological risk, together with a larger installation weight, will require significant costs for development, testing, debugging and subsequent implementation, but at the same time on-board air conditioning system scheme without air extraction from the engines will achieve a significant increase in fuel efficiency at the level of the entire aircraft.

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