Generation and confinement of uniform magnetic fields with distributions of surface currents
This paper presents the methodology for generation and confinement of a uniform magnetic field of intensity H/sub 0/ in an arbitrary assigned polyhedral cavity C enclosed by planar surfaces s/sub h/. The design methodology presented in this paper can generate novel self-shielding polyhedral structures of surface currents. Unlike in conventional solenoid magnet, the field generated by these structures is perpendicular to the main axis of the cavity.
Equivalent structures of permanent magnets and electric currents designed to generate uniform fields
Generation and confinement of a magnetic field by means of permanent magnets as well as time‐independent electric currents are analyzed, and the conditions of existence of uniform field solutions are established in the general case of structures that enclose a region of arbitrary geometry. Basic properties of distributions of the electric currents are compared with the properties of yokeless structures of permanent magnets intended to generate the same uniform field within the same region.
Experimental Study for a Double-Glazed Forced-Flow Solar Collector/Regenerator
Experimental study of a double-glazed forced-convection solar collector/regenerator for absorption solar cooling is presented. The south facing experimental solar collector/regenerator with 10 deg slope is located at Kaohsiung, Taiwan at 120{degree}19minutesE longitude and 22{degree}34minutesN latitude. The size of the collector is 1 m wide and 7 m long with an effective regeneration area of 0.9 m by 6 m. Previous study for single-glazed forced-convection solar collector/regenerator operated at the same location has shown to have a best day-average efficiency of 17%. In order to raise the system performance, a double-glazed collector/regenerator is constructed such that air can be preheated in the upper channel flow. The preheated air is then conducted into the lower channel where it contacts with the film flow of solar heated lithium-chloride solution and regenerates the solution by carrying out the evaporated water vapor. The preheated air has lower relative humidity but the same humidity ratio since it is sensibly heated. Therefore, the regeneration driving potential is increased. The present study shows that the best day-average efficiency can reach 20% which increases the feasibility of the open-cycle absorption solar cooling system. Effects of controlling parameters on the collector/regenerator performance are studied, and heat and mass transfer correlationsmore » are also presented for design purposes.« less