| 摘要 |
Cryogenic fluid piston pump functions as stationary dispensing pump, mobile vehicle fuel pump etc., and can pump vapour and liquid efficiently even at negative feed pressures, thus permitting pump location outside a liquid container. Piston inducts fluid by removing vapour from liquid in an inlet conduit faster than the liquid therein can vaporize by absorbing heat, and moves at essentially constant velocity throughout an induction stroke to generate an essentially steady state induction flow with negligible restriction of flow through an inlet port. Stroke displacement volume is at least two orders of magnitude greater than residual or dead volume remaining in cylinder during stroke changeover, and is greater than volume of inlet conduit. Cryogenic tank has a liquid compartment, a vapour compartment, and inlet and overflow conduits. Inlet conduit receives liquid from dispensing pump and widely disperses liquid into liquid tank to contact and condense vapour. Overflow conduit restricts flow of excess liquid from liquid compartment to vapour compartment. Excess pressure in tank or temperature of overflow liquid from conduit is detected to automatically stop dispensing pump. As a fuel pump, the pump selectively receives cryogenic liquid and vapour from respective conduits communicating with tank, and pumps cryogenic liquid to satisfy relatively heavy fuel demand of engine, which, when satisfied, also pumps vapour to reduce vapour pressure in the tank while sometimes satisfying relatively lighter fuel demand. |
