Comparison on Simulation and Experiment of Supply Air through Metro Vehicle Air Conditioning Duct

2010 ◽  
Vol 44-47 ◽  
pp. 1724-1728
Author(s):  
Hong Ge Tao ◽  
Huan Xin Chen ◽  
Jun Long Xie ◽  
Jun Zhi Jiang

CFD technique is often employed to simulate and optimize air duct design, but the corresponding experiment validation in metro vehicle is rare. By taking an independent metro vehicle duct as research object in this paper, supply air through air duct is simulated and compared with the actual test results from the angle of supply air velocity at each outlet and supply air volume through several outlets of air duct. The results show that the relative deviation of simulation and test value of air velocity at most of the outlets are within or near ±20%, which is acceptable for the engineering applications. Moreover, the ratio of supply air volume through several outlets to the corresponding total supply air volume through main air duct or flat duct in the case of simulation is consistent with that in the case of experiment. It can be concluded that numerical simulation method is effective and reliable in air duct optimization design of metro vehicle.

2008 ◽  
Vol 12 (3) ◽  
pp. 15-32 ◽  
Author(s):  
Parameshwaran Rajagopalan ◽  
Karunakaran Rajasekaran ◽  
Senthilkumar Alagarsamy ◽  
S. Iniyan ◽  
Mohal Lal

In the quest for energy conservative building design, there is now a great opportunity for a flexible and sophisticated air conditioning system capable of addressing better thermal comfort, indoor air quality, and energy efficiency, that are strongly desired. The variable refrigerant volume air conditioning system provides considerable energy savings, cost effectiveness and reduced space requirements. Applications of intelligent control like fuzzy logic controller, especially adapted to variable air volume air conditioning systems, have drawn more interest in recent years than classical control systems. An experimental analysis was performed to investigate the inherent operational characteristics of the combined variable refrigerant volume and variable air volume air conditioning systems under fixed ventilation, demand controlled ventilation, and combined demand controlled ventilation and economizer cycle techniques for two seasonal conditions. The test results of the variable refrigerant volume and variable air volume air conditioning system for each techniques are presented. The test results infer that the system controlled by fuzzy logic methodology and operated under the CO2 based mechanical ventilation scheme, effectively yields 37% and 56% per day of average energy-saving in summer and winter conditions, respectively. Based on the experimental results, the fuzzy based combined system can be considered to be an alternative energy efficient air conditioning scheme, having significant energy-saving potential compared to the conventional constant air volume air conditioning system.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3187
Author(s):  
Keon-Woo Park ◽  
Chul-Hwan Kim

In this study, we describe the development of a plug-in type of switchgear that can control bidirectional power flow. This switchgear system can connect distributed generations such as photovoltaic and wind turbine generation, and AC and DC loads. The proposed switchgear system consists of an inverter for connecting distributed generations and DC load, a static transfer switch (STS) that can control and interrupt the bidirectional power flow, and an intelligent electronic device (IED) that can control each facility using a communication system. Since the topology inside the switchgear is composed of DC bus, it can be operated as a plug-in type of system that can be used by simply connecting the converters of various distributed generations to the inverter in the developed switchgear system. In this study, we describe the overall structure of the proposed switchgear system and the operation of the components. In addition, prototypes of each facility are developed and the results of building a small testbed are presented. Finally, we verify the operation of the inverter by performing an experiment on the testbed and show that throughout a test sequence the proposed switchgear system works normally. The contributions of this study are the development of a plug-in type of switchgear for AC/DC and the actual test results presented through prototype development and testbed configuration.


2018 ◽  
Vol 38 ◽  
pp. 04012
Author(s):  
Sai Feng Xu ◽  
Xing Lin Yang ◽  
Zou Ying Le

For ocean-going vessels sailing in different areas on the sea, the change of external environment factors will cause frequent changes in load, traditional ship air-conditioning system is usually designed with a fixed cooling capacity, this design method causes serious waste of resources. A new type of sea-based air conditioning system is proposed in this paper, which uses the sea-based source heat pump system, combined with variable air volume, variable water technology. The multifunctional cabins’ dynamic loads for a ship navigating in a typical Eurasian route were calculated based on Simulink. The model can predict changes in full voyage load. Based on the simulation model, the effects of variable air volume and variable water volume on the energy consumption of the air-conditioning system are analyzed. The results show that: When the VAV is coupled with the VWV, the energy saving rate is 23.2%. Therefore, the application of variable air volume and variable water technology to marine air conditioning systems can achieve economical and energy saving advantages.


2010 ◽  
Vol 97-101 ◽  
pp. 1863-1866
Author(s):  
Liang Yang ◽  
Li Xu

Performance of tool has always been a puzzle in the course of high manganese steel drilling. In this paper, improvement of drill tool is been done on drill bit structure and parameters of cutting tip by means of analyzing geometric parameter. By utilizing simulation method correctly, the influence of bit parameter on drilling force is analyzed. Meanwhile, by adopting the way of dividing into groups, comparison experiment between improved and no improved has been done. The comparison analysis of test results is carried out including tool life, wear and drilling force. The conclusion showed that the improved bit has better performance.


2014 ◽  
Vol 496-500 ◽  
pp. 1176-1179
Author(s):  
Li Tan ◽  
Yu Fang

LTX-77 test system is a large IC test system that is used for various kinds of analog IC, digital IC and analog digital mixed IC. It can be used to test DC parameters, AC parameters and logic functions. In the paper, the IC test platform is LTX-77 test system. IC ADC0804 was tested as the test object. The test method of IC is described in the view of actual test. The test results show that the test system is convenient and accurate, which has important practical value for IC manufacturers and users.


2015 ◽  
Vol 2015 ◽  
pp. 1-13
Author(s):  
Yang Liu ◽  
Shuhan Wang ◽  
Peng Dong ◽  
Xiangyang Xu

An electric oil pump (EOP) was integrated into the hydraulic system and an automatic transmission (AT) mechanical oil pump (MOP) was downsized. These processes were performed to combine a start-stop function with the AT and further improve the transmission efficiency. Furthermore, this study established a dynamics model of power loss and leakage of an 8-speed AT; a flow-based control algorithm of the EOP was then developed to realize the start-stop function and support the MOP to meet the flow requirement of the system. Based on a driving simulation method, sizes of the MOP and EOP that ensured optimal fuel economy were selected. A control strategy for the starting clutch was also developed to minimize the starting delay of the test vehicle. A test environment on a rig and prototype vehicle was established to verify the feasibility of the proposed control strategies. The test results indicated that the transmission functioned favorably with the novel two-pump system presented, and a quick and smooth starting performance was achieved when the engine was restarted. The findings in this study are extremely valuable for forward designs of an AT for realizing start-stop function and improving efficiency.


2001 ◽  
Vol 91 (6) ◽  
pp. 2459-2465 ◽  
Author(s):  
Paraya Assanasen ◽  
Fuad M. Baroody ◽  
Edward Naureckas ◽  
Julian Solway ◽  
Robert M. Naclerio

We tested the hypothesis that decreasing nasal air volume (i.e., increasing nasal turbinate blood volume) improves nasal air conditioning. We performed a randomized, two-way crossover study on the conditioning capacity of the nose in six healthy subjects in the supine and upright position. Cold, dry air (CDA) was delivered to the nose via a nasal mask, and the temperature and humidity of air were measured before it entered and after it exited the nasal cavity. The total water gradient (TWG) across the nose was calculated and represents the nasal conditioning capacity. Nasal volume decreased significantly from baseline without changing the mucosal temperature when subjects were placed in the supine position ( P < 0.01). TWG in supine position was significantly lower than that in upright position ( P < 0.001). In the supine position, nasal mucosal temperature after CDA exposure was significantly lower than that in upright position ( P < 0.01). Our data show that placing subjects in the supine position decreased the ability of the nose to condition CDA compared with the upright position, in contrast to our hypothesis.


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