Measurement of Leak Flow Rates of Mobile Air-Conditioning Systems

2005 ◽  
Author(s):  
Denis Clodic ◽  
Lionel Palandre
2005 ◽  
Author(s):  
Walfre Franco ◽  
Weihua Cai ◽  
Mihir Sen ◽  
K. T. Yang

Hydraulic networks constitute a fundamental part of heating, ventilating and air conditioning systems in buildings and high rises. In order to optimize large and complex networks it is important to understand the effects of operational changes in one loop on the others. The objective of this study is to investigate the time-independent flow and thermal interactions between secondary user-loops, in a hydraulic network that is used for cooling, when the system goes from one steady state to another. The study is experimental and was carried out on a facility which has a primary cooling loop, three secondary loops, and a primary heating loop. The flow was abruptly changed by actuating a valve in one of the loops causing changes in the other two loops. Results show that the change of flow rates and pressure differences in the other two loops are linearly dependent on that in the actuating loop. The dependence is also affected by the initial operational condition of the network. The thermal interaction, however, is different in that it is nonlinearly coupled with the hydrodynamic interaction.


Proceedings ◽  
2019 ◽  
Vol 23 (1) ◽  
pp. 1 ◽  
Author(s):  
Usama Sohail ◽  
Conrad Kwiatek ◽  
Alan S. Fung ◽  
Darko Joksimovic

Wastewater is an abundant and an underutilized thermal energy source that experiences steady temperatures and predictable flow rates year-round. These characteristics make it an excellent candidate to serve as the heat source and sink for heat pump based HVAC (Heating, Ventilation, and Air Conditioning) systems capable of providing both heating and cooling. The potential for wastewater heat recovery is evaluated for a large hospital in the greater Toronto area, in Canada. A model was developed to calculate the operational savings and benefits of the proposed system, and the results from that analysis were used to carry out an economic analysis.


2019 ◽  
Vol 6 (3) ◽  
pp. 80-85
Author(s):  
Denis Igorevich Smagin ◽  
Konstantin Igorevich Starostin ◽  
Roman Sergeevich Savelyev ◽  
Anatoly Anatolyevich Satin ◽  
Anastasiya Romanovna Neveshkina ◽  
...  

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.


Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 81
Author(s):  
Rongjiang Ma ◽  
Shen Yang ◽  
Xianlin Wang ◽  
Xi-Cheng Wang ◽  
Ming Shan ◽  
...  

Air-conditioning systems contribute the most to energy consumption among building equipment. Hence, energy saving for air-conditioning systems would be the essence of reducing building energy consumption. The conventional energy-saving diagnosis method through observation, test, and identification (OTI) has several drawbacks such as time consumption and narrow focus. To overcome these problems, this study proposed a systematic method for energy-saving diagnosis in air-conditioning systems based on data mining. The method mainly includes seven steps: (1) data collection, (2) data preprocessing, (3) recognition of variable-speed equipment, (4) recognition of system operation mode, (5) regression analysis of energy consumption data, (6) constraints analysis of system running, and (7) energy-saving potential analysis. A case study with a complicated air-conditioning system coupled with an ice storage system demonstrated the effectiveness of the proposed method. Compared with the traditional OTI method, the data-mining-based method can provide a more comprehensive analysis of energy-saving potential with less time cost, although it strongly relies on data quality in all steps and lacks flexibility for diagnosing specific equipment for energy-saving potential analysis. The results can deepen the understanding of the operating data characteristics of air-conditioning systems.


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