thermal water and gas management in pem fuel cell stacks

... τψπιχαλ ΠΕΦΧ σψστεµ [42] 14 1.4 Πολψµερ ελεχτρολψτε φυελ χελλ 15 = 1.229 V 1.2 ∼ 0.95 - 1.05 V E cell /V ∆G/(2F) OCV η act 0.8 η 0.6 η ohm conc 0.4 0.2 0 2000 4000 i ave 6000 8000 -2 /Am 10000...

Ngày tải lên: 11/09/2015, 10:02

... differential between the fuel cell stack and the operating environment make thermal management a challenging problem in PEM fuel cells The temperature distribution inside the fuel cell has important ... model of a PEM fuel cell has been developed to simulate the hygro and thermal stresses in PEM fuel cell, which are occurring during the cell operation due to the changes of temperature and relative ... of hygro -thermal stresses into actual three-dimensional fuel cell model This model is used to investigate the hygro and thermal stresses in PEM fuel cell, which developed during the cell operation...

Ngày tải lên: 05/09/2013, 14:58

... remain uniform in both GDLs [20] • Species are considered in gas phase only (no liquid water) in the gas channels and in the GDLs 2-phase water transport in the electrodes will be introduced in ... transfer intensification in energy conversion devices His research fields include mainly mass transfer in order to improve water management in fuel cells, numerical modeling and control aspects of PEMFC ... between and 3, liquid water will exist in the cell for intermediate and high currents However, the presence of liquid water is not intrinsically damageable to the cell Flooding, where the liquid water...

Ngày tải lên: 05/09/2013, 14:58

... computational domain of a planar ambient air-breathing PEM fuel cell and (b) longitudinal cross section of 3 -cell fuel cell stack ISSN 2076-2895 (Print), ISSN 2076-2909 (Online) ©2011 International ... distribution in the air-breathing fuel cell is dependent on the membrane electrode assembly water content The net water balance of the cell is a complex coupling of cell self-heating and water production ... result in rupture of the membrane The small temperature differential between the fuel cell stack and the operating environment make thermal management a challenging problem in PEM fuel cells As...

Ngày tải lên: 05/09/2013, 14:58

... results in water transport from anode to cathode; and (ii) diffusion associated with water- content gradients in the membrane One of the main difficulties in managing water in a PEM fuel cell is ... non-isothermal model of a PEM fuel cell that incorporates the significant physical processes and the key parameters affecting fuel cell performance The model accounts for both gas and liquid phase in ... reactant species in this design of the perforated type gas distributor One of the new architectures in PEM fuel cell design is a tubular-shaped fuel cell Fuel cell companies and research institutes...

Ngày tải lên: 05/09/2013, 14:58

... the inlet, and iodinating resin beds at the outlets to maintain bacterial control in the water supply system of the spacecraft.29 Fuel Cell Product Water When hydrogen and oxygen are combined in ... Waste management Urine stored in bags Used Feces stored in bags Used Urine vented Used Feces stored in bags and vacuum dried Used Urine stored in tank and vented Used * Used Feces stored in bags and ... Suppression Water Recovery and Management (WRM) Waste Management (WM) Waste Storage & Return Fecal Urine Waste Processing Processing Combined Potable/Hygiene Urine Collection and Processing Pretreatment...

Ngày tải lên: 10/08/2014, 20:20

... convective and diffusive heat and mass transfer, electrode kinetics, transport and phase-change mechanism of water, and potential fields in a micro PEM fuel cell with nature inspired gas flow channels ... and stoichiometric flow ratio The inlet velocities of air and fuel are calculated according to [20]: u in ,c = ζ c I RTin ,c AMEA xO2 ,in Pc Ach 4F (39) u in ,a = ζ a I RTin ,a AMEA 2F x H ,in ... domain The full computational domains for the micro PEM fuel cell consist of cathode and anode gas flow fields, and the MEA are shown in Figure 2.2 Model equations 2.2.1 Gas flow channels In the...

Ngày tải lên: 09/09/2015, 10:17

... reductions and low recovery of gas demand “The excess of gas that pushed gas market prices downwards in 2009 should continue to decline in 2011, owing to the recovery of gas demand growth in Asia and in ... additions in deepwater areas an increasingly prominent feature in global oil and gas production  © The Economist Intelligence Unit Limited 2011 Deep water ahead? The outlook for the oil and gas industry ... the oil and gas industry in 2011 Key points n NOCs are playing an increasingly assertive role in exploration and production, while driving harder bargains with the IOCs they work with n And NOCs...

Ngày tải lên: 06/12/2015, 23:06

... Services: They include three agents: SSA, TEA, and ASA The first agent, SSA, maintains a database of information about ABs This information is used for encrypting and decrypting sensitive data and metadata ... with sensitive data and metadata, including access control and dissemination control metadata ABC constructs an AB by putting together data, metadata, and adding a virtual machine After this stage, ... Web services in the system proposed for independent navigation of the blind and the visually impaired When submitting their location information to the cloud, a blind user (and, in fact, any...

Ngày tải lên: 31/07/2013, 09:43

... requiring natural gas or propane as a source of heat; thereby saving valuable and diminishing  natural resources. Space heaters and furnaces are excellent candidates. Stoves and other  cooking units such as barbecue grills can also be fueled by the water hybrid system. Such  ... converts water into combustible gaseous fuel to power your engine. A water tank and pump  store and supply water for the generator. Simple electronic signals from the HyTronics Module  initiate and sustain the creation of hydrogen and oxygen within the Generator. An In Dash  ... about anywhere space permits in the vehicle, even in the trunk. But, everything is simplified by  placing it near the engine since that minimizes routing of hoses, gauge lines, and electrical  wiring.     Water Tank and Pump  Obviously this is the simplest part of the whole system. Just about any large container will hold ...

Ngày tải lên: 19/02/2014, 04:20

... thin Body skin is dry and thin Face turns pale and eyes sink The facial bones become prominent and bones and skin come in contact due to wasting Both temporal sink Clinical features include: Purulent ... Gulqand, etc Tabreed (Cooling) and Tarteeb (Wettting) 148 INDIAN J TRADITIONAL KNOWLEDGE, VOL 4, NO 2, APRIL 2005 Following has been recommended in the treatment of Dique: Sitz bath in lukewarm water ... disease, Sil and the causing agent Ajsame Khabitha (microorganisms) Symptoms and signs Pulse is subtle, firm, continuous and weak Fever is continuous till morning Fever is constant and due to the...

Ngày tải lên: 15/03/2014, 03:20

... transitions, and secondarily on phosphate binding Although having very different oxygen-binding properties, both Hbs respond to an increase in water activity with an increase on oxygen afnity, indicating ... indicating preferential binding of water molecules to the R state The allosteric effectors signicantly affect water and O2 binding (Fig 2), and both chloride and 0.1 mM ATP induced an increase of O2 afnity, ... activity in different experimental conditions: for the stripped Hb (in an ATP and chloride-free buffer solution), in the presence of 0.1 mM and mM of ATP, in a buffer containing 100 mM NaCl, and a...

Ngày tải lên: 23/03/2014, 13:20

Ngày tải lên: 24/03/2014, 00:21

... gross margin declines than trading and services firms, their overall cost of doing business (including selling & administrative costs) increased at both the two and three year mark post listing, compared ... Returns in the UK Water Industry Since Privatisation”, Aberdeen Papers in Accountancy, Finance & Management, Working Paper 00-10 Carlin, T., (2005), “Debating the Impact of Accrual Accounting and ... of pre and post listing financial statement data Consequently, without 2006- and 2007-listing firms in the research sample, the remaining dataset consists of listing year cohorts, including firms...

Ngày tải lên: 02/04/2014, 00:13

... maximum of two SUs fit into the upper band At this point, it is more convenient to move the SU in the lower band to the empty channel in the upper band, avoiding in this way future interference if a ... the impact of incorporating admission control on the forced termination of SUs and also the impact of deploying channel allocation with preference and repacking on the interference In Section 4, ... to and decreasing (increasing) it reduces (augments) the acceptance rate of SU requests, which will in turn decrease (increase) ft both P2 and the interference Note that the definition of t in...

Ngày tải lên: 21/06/2014, 17:20

... issues), creating and maintaining good working relationships as well as a healthy work environment • Information management: Collecting and keeping data, data security and confidentiality, and the use ... formal training in it Certainly IVF has evolved rapidly over the last two -and- a-half decades or so: from its beginnings as a highly experimental procedure in the late 1970s, culminating in the birth ... below) • Insufficient knowledge and/ or understanding of what was required • Inadequate information management resources and/ or systems (includes documentation and data) • Wrong attitudes or an inappropriate...

Ngày tải lên: 28/06/2014, 17:20

... hour Blow room, drawing, combing and roving Carding Spinning Winding Twisting, warping, sizing and weaving 15 20 45 30 20 To minimize risk of industrial diseases such as byssinosis (lung disease) ... lapping Combing Drawing Roving Spinning Winding and spooling Twisting Warping Knitting Weaving 45–60 50–55 55–60 55–60 55–65 50–60 50–60 45–60 60–65 60–65 55–70 60–65 70–85 Raw wool storage Mixing ... blowing to roving preparation and for manufacture of nonwovens 0.2 mgm per cubic meter, for spinning, twisting, winding and warping 0.75 mgm per cubic metre, for sizing and weaving With the industrial...

Ngày tải lên: 28/06/2014, 22:20

... all International Accounting Standards (IAS) and related interpretations issued by the former International Accounting Standards Committee (IASC), and the International Financial Reporting Standards ... differences exist in the amount and precision of private information in the hands of institutional and individual investors The higher level of understanding of institutional investors also implies ... The importance behind examining the determinants of earnings management is to minimize potential wrongdoing, conflict, and a sense of mystery in accounting information used by financial managers...

Ngày tải lên: 13/07/2014, 21:13

... lasting and can migrate into the water system The USEPA MCL in drinking water is ␮g/l The WHO guideline maximum value is ␮g/l in drinking water The EU Drinking Water Directive states a mandatory ... work includes curing (drying the skin), fleshing (removal of fat), washing, dehairing, bating (raising the pH by adding ammonium salts), pickling and de-greasing The skins then are tanned and ... See flue gas cleaning air pressure test A method for testing of drainage installations It involves filling the water seals and closing off the ends of the stacks and outlets into the main sewer...

Ngày tải lên: 02/08/2014, 02:20

... the atmospheric inputs, resulting in a net gain, more evident in S1 for 24 NO and SO (depending mainly on the rainfall volume), and in S4 for H K, , PO Mg, Fe and Mn (depending mainly on the ion ... be explained by low rain intensity, slight slopes, high infiltration and absence of impermeable layers near the soil surface Drainage Drainage (D) increased with rainfall (figs and 2), and significant ... (Birkeland, 1984) This is due to differences in the amount of excess water in the soil produced by the different rainfall, favouring leaching processes of nutrients in the soil, accordingly resulting...

Ngày tải lên: 08/08/2014, 18:21