A new membrane electrolyte assembly (MEA) preparation method for polymer electrolyte membrane fuel cell (PEMFC) was developed by applying the directly printing catalyst on membrane technique.This method was simple and...A new membrane electrolyte assembly (MEA) preparation method for polymer electrolyte membrane fuel cell (PEMFC) was developed by applying the directly printing catalyst on membrane technique.This method was simple and easy to be controlled as verified by repetition experiment. When the membrane with catalyst prepared by the new technique and the electrode with diffusion layer was only sandwiched but not hot pressed, this kind of MEA was called not-hot-press MEA (NPMEA) and its fuel cell performance was better than that of MEA which was hot pressed (HPMEA).The effects of 6 different kinds of solvents in catalyst mixture ink on the performance of fuel cell were assessed.It was discovered that iso-propanol was the best solvent in catalyst mixture ink and showed the best performance of fuel cell. Finally several MEAs prepared by different ways were tested on fuel cell station and it was reported that the performance of MEA prepared by the directly printing catalyst on membrane technique was the best in the whole voltage region.展开更多
Foam fracturing is an important technology in the development of low permeability oil/gas reservoirs. The heat transfer characteristics of foam fracturing fluid are directly relevant to the calculation of pressure dro...Foam fracturing is an important technology in the development of low permeability oil/gas reservoirs. The heat transfer characteristics of foam fracturing fluid are directly relevant to the calculation of pressure drop in the well, the optimum choice of fracturing parameters and the accurate evaluation of fracturing results. CO 2 foam fracturing fluid behaves as a non-Newtonian fluid. The convective heat transfer characteristics of CO 2 foam fracturing fluid were experimentally investigated on the newly constructed large-scale test loop under downhole conditions with CO 2 in supercritical state, the pressure up to 40 MPa. From the test data, corresponding correlations for convective heat transfer were obtained and the influences of pressure, temperature and flow rate were also studied. The convective heat transfer coefficient increased with the increase of temperature and flow rate, while the effect of pressure was much more complicated.In most cases, with the increase of pressure the coefficient tended to decrease.展开更多
文摘A new membrane electrolyte assembly (MEA) preparation method for polymer electrolyte membrane fuel cell (PEMFC) was developed by applying the directly printing catalyst on membrane technique.This method was simple and easy to be controlled as verified by repetition experiment. When the membrane with catalyst prepared by the new technique and the electrode with diffusion layer was only sandwiched but not hot pressed, this kind of MEA was called not-hot-press MEA (NPMEA) and its fuel cell performance was better than that of MEA which was hot pressed (HPMEA).The effects of 6 different kinds of solvents in catalyst mixture ink on the performance of fuel cell were assessed.It was discovered that iso-propanol was the best solvent in catalyst mixture ink and showed the best performance of fuel cell. Finally several MEAs prepared by different ways were tested on fuel cell station and it was reported that the performance of MEA prepared by the directly printing catalyst on membrane technique was the best in the whole voltage region.
文摘Foam fracturing is an important technology in the development of low permeability oil/gas reservoirs. The heat transfer characteristics of foam fracturing fluid are directly relevant to the calculation of pressure drop in the well, the optimum choice of fracturing parameters and the accurate evaluation of fracturing results. CO 2 foam fracturing fluid behaves as a non-Newtonian fluid. The convective heat transfer characteristics of CO 2 foam fracturing fluid were experimentally investigated on the newly constructed large-scale test loop under downhole conditions with CO 2 in supercritical state, the pressure up to 40 MPa. From the test data, corresponding correlations for convective heat transfer were obtained and the influences of pressure, temperature and flow rate were also studied. The convective heat transfer coefficient increased with the increase of temperature and flow rate, while the effect of pressure was much more complicated.In most cases, with the increase of pressure the coefficient tended to decrease.
