PDF Publication Title:
Text from PDF Page: 062
Transition points from the solid lines to dashed lines (for the various current densities) in Figure 24 indicate the projected temperature dependent operational limits of the SFWEM for the specific current density levels indicated.2 The capability of the module to perform in exces of the projected 323 mA/cm (300 ASF) by demonstrating operation at 538 mA/cm (500 ASF) showed that the design-related objectives were successfully met. Effects of Operating Pressure. An operating pressure test was completed on the SFWEM which covered the range of ambient to 1724 kN/m (250 psia). Figure 2 shows that the SFWEM voltage increased at an average rate of 0.6 mV per kN/m (4.1 mV per psia). The reason for this increase was discussed in the Module Design Verification Single Cell Test section. Effects of Process Fluid Pressure Differentials. The SFWEM was designed and run with the 02 pressure greater than the H2 pressure. This was done to avoid any possibility of H2 leaking into the 02 cavity. SFWEM performance actually improved, as shown in Figure 26, when the H2 pressure was greater than the 02 pressure. The data shows a 0.42V increase in module voltage (70 mV pr average cell) as 2 the 02 to H2 differential pressure is varied from -34 kN/m (-5 psid) to +34 kN/m (+5 psid). Effects of Cyclic Operation. During the last five days of the parametric test program the effects of cyclic operation on the performance of the SFWEM was investigated. For about six hours each day for five days the current was cycled on and off. Each cycle consisted of 58 minutes with the current on, followed by 36 minutes with the current off simulating the sunlit/shade cycles of a near- earth orbit. This type of operation would allow the 0 Generating Subsystem to use cheaper power (122 kg/kw (270 lb/kw) for sunlit orbit, only, versus 268 kg/kw (590 lb/kw) for continuous operation). During the current off portions of the cycle the gas pressures in the STS were held at their operating levels by a regulated N2 source. When the current is turned off, recombination begins in the module.2 For the particular SFWEM'design this caused the H2 pressure to drop below the 02 and system pressure by too great an amount. Excess pressure differentials can be detrimental to the SFWEM so, therefore, N2 pressure was used to keep the pressures at the desired levels. The performance of the SFWEM was improved by the cyclic test. The module voltage dropped by 0.12V for an average decrease in cell voltage of 20 mV. This would be equivalent to a savings in total equivalent weight of 1.0 kg (2.2 Ib) based on the 0 requirements of a six-man crew aboard a near-earth orbit spacecraft. The total savings in power source weight when the effects of using the cheaper power is included exceeds 185 kg (405 lb) for a six-man system. Endurance Testing Endurance testing of the SFWEM immediately followed completion of the parametric tests. Figure 27 shows the stack voltage of the six cell module, maximum and minimum cell voltage, and current density as a function of time. Table 7 lists in operating parameters investigated. 55 ,Cilf Systcms, Ac.PDF Image | WATER ELECTROLYSIS MODULE
PDF Search Title:
WATER ELECTROLYSIS MODULEOriginal File Name Searched:
19750012429.pdfDIY PDF Search: Google It | Yahoo | Bing
Salgenx Redox Flow Battery Technology: Power up your energy storage game with Salgenx Salt Water Battery. With its advanced technology, the flow battery provides reliable, scalable, and sustainable energy storage for utility-scale projects. Upgrade to a Salgenx flow battery today and take control of your energy future.
CONTACT TEL: 608-238-6001 Email: greg@salgenx.com (Standard Web Page)