Patent GB-1467142-A (GB)
Title: Thermohydraulic engines
IPC: F01B29/00
Filed: 1974-04-23
Abstract: 1467142 Thermohydraulic engines; liquid pistons SOC EUROPEENE DE PROPULSION 23 April 1974 [26 April 1973 (5)] 17710/74 Headings F1B and F1M A thermohydraulic engine comprises a plurality of expansion chambers 118-121 in fluid communication with one or more variable volume compartments 101 operatively connected to a power output member 103, the or each compartment 101  being filled and at least one of the expansion chambers 118-121 being partially filled with liquid during use of the engine and there being means for introducing into at least one of the partially filled expansion chambers when the output member has reached a predetermined angular position a product (e.g. steam, combustible fuelair mixture) capable of yielding energy by expansion, the number of the variable volume compartments 101 being less than twice the number of expansion chambers 118-121. In Fig. 3, water is forced from chamber 119 by the expanding steam or combustion products through conduit 106, distribution member 104 and conduits 105 and 301 to compartment 101 to push piston 102 down and drive member 103. On the upstroke of piston 102 the water is forced through conduit 303 and drives a liquid exchange device 300, Fig. 5 (not shown) before entering a reservoir 117, from which cleaner water is drawn by the exchange device 300 to pass via distribution member 104 to chamber 120, to which conduit 106 is now connected via conduit 113. The member 104 is driven from drive member 103, which may also be used to drive the exchange device 300, Fig. 4 (not shown) when compartment 101 and reservoir 117 are connected in parallel, there then also being a reservoir (408) with free piston or diaphragm (409) between the conduits 303, 304. In Figs. 4 and 1 (not shown) separate conduits (109-(116) are provided for inlet to and outlet from the chambers 118-121. In Fig. 1, the distribution member 104 moves the position of conduit 106 each time the piston 102 reaches top and bottom dead centres. The connections to the inlet conduits to the chambers 118-121 may be made slightly after the piston 102 has passed b.d.c. so as to introduce a cooling spray into each chamber to assist condensation immediately after the expansion stroke instead of waiting to inject the whole of the liquid in the next cycle immediately before admission of the steam or combustible mixture. In Fig. 6, the variable volume compartments 608-613 have liquid passed to them from expansion chambers 614-619 via conduits 620, 622, 624, 626, 628, 630 during expansion and supply liquid to the expansion chambers via conduits 621, 623, 625, 627, 629 and 631. During the sixth of a crank-shaft 601 revolution beginning at the position shown in Fig. 6, both conduits 627 and 628 are open so that the liquid volume in chamber 618 remains substantially constant, the amount of liquid entering via 627 being substantially equal to that leaving via 628. After piston 606 passes b.d.c., conduit 627 is closed and compression  condensation and/or dissolution can occur. One of the chambers 614-619 may be replaced by reservoirs of used and regenerated water to which the conduits 629, 630 are respectively connected. The used water may be discharged into a pressure reservoir to create a store of hydraulic energy. Fig. 7 shows an engine having fine expansion chambers 701-705 associated with a revolving distributer 700 rotated at one fifth of the speed of drive-shaft 601 connected to pistons 602-607 associated with six variable volume chambers (cylinders 608-613). Operation is similar to that of the embodiment of Fig. 6 since, during the sixth of a revolution of the shaft 601 following the illustrated position, the expansion chamber receives substantially the same volume of liquid from cylinder 611 as it delivers to cylinder 612. Replacing one of the expansion chambers by a reservoir ensures that impure water is replaced by cleaner water. In Fig. 8 and 9 (not shown), a stator has a trochoidal profile with four lobes and contains a pentagonal rotor 800 with sides 811-815 forming variable volume compartments also denoted by 811-815, which compartments are connected by conduits 816-821 with expansion chambers 822-824 and with a reservoir by a passage 825. In operation, water is forced from the chamber 822 via conduit 817 by expansion of steam or combustion products and enters compartment 812. Water in compartment 811 is forced via conduit 816 to chamber 822 via an atomizer so that as before a cooling phase without compression is obtained in chamber 822, followed by the compression phase. If desired, the shaft (802) may be held stationary so that the 'stator' and rotor 800 both rotate at constant speeds enabling the liquid and gaseous phases in the chambers to be separated by centrifugal force.