THERMAL PULSER

Abstract: A thermal pulser is used for converting low-quality thermal energy in a fluid into high-energy pulses. The pulser comprises a chamber (1) which is divided in a fluid-tight manner by a member (3) yielding to pressure and which on the respective side of the pressure-yielding member has an inlet (1a') for a high-energy fluid whose energy content should be converted, and an outlet (1b') for a fluid having a lower energy content, said inlet and outlet being subjected to the influence of a valve device (11) for switching the inlet and outlet functions, the pressure-yielding member (3) communicating with a pressure accumulator (6) which is adapted in response to a fluid pressure increase on one side of the member (3) to build up, against the action of a bias (9c), a predetermined quantity of energy on the other side of the member (3) and, by suppression of the bias, to release said quantity of energy as a short energy pulse.

Description: THERMAL PULSER The present invention relates to a thermal pulser which is adapted, according to the object of the inven¬ tion, to convert low-quality thermal energy into high- energy pulses. According to the invention, this object is achieved by means of a pulser having the features recited in the accompanying claims. The invention will be described in greater detail hereinbelow with reference to the accompanying drawings, in which Fig. 1 is a part sectional view of a pulser according to the invention, and Fig. 2 illustrates an evaporator-condenser system including the pulser according to the invention. Reference is now made to Fig. 1. The pulser I comprises a cylindrical casing whose interior is di¬ vided by means of sealing transverse partitions into a central pressure chamber 1 for a fluid, such as oil, and two terminal spring compartments 2. A piston 3 divides the pressure chamber 1 into two spaces la, l between which a considerable pressure difference may prevail in operation. On either side of the piston 3 is fixed one end of a rod 4 which sealingly extends through the asso¬ ciated transverse partition and which at its other end in the associated spring compartment 2 is fixed to a second, pierced piston 5 which by means of a spring 6 attached to it, here a conical helical spring, is connected to another pierced piston 7 disposed in the spring compartment. On its other side, the piston 7 is connected to a piston rod 8 through which it drives a power engine, such as a pump. The piston rod 8 or piston 7 also controls a valve mechanism described in greater detail hereinbelow. A lever 9 pivotally mounted on the outer side of the casing of the pulser and extending in the lon¬ gitudinal direction of this casing is provided on one lever arm with two lugs 9a, 9b which are spaced apart in the longitudinal direction of the casing and extend into the spring compartment 2 through slots therein, under the load exerted by a spring 9c acting on the other arm of the lever 9. The lug 9b is the rear lug, counting from the pressure chamber 1. The lugs 9a, 9b are designed with cam surfaces controlling the movement of the pistons 5 and 7 against the action of the spring 9c. The cam surfaces are such that the rear lug 9b allows the piston 7 to pass in both direc¬ tions, while the forward lug 9a does not allow the piston 7 to pass in the direction of the pressure chamber 1 but allows the piston 5 to slide up on it, during which slide engagement the rear lug 9b allows the piston 7 to pass in the outward direction. The piston 7 cannot pass the lug 9b until the piston 5 has slid up on the lug 9a. Said spaces of the pressure chamber are in fluid communication by in(out)lets la', lb' with one chamber of a respective piston and cylinder assembly 10 whose other chambers, by said valve mechanism designated 11, are alternately connectible to a pressure fluid source, for instance an evaporator, through an inlet conduit 12, and pressure fluid receiving means, e.g. a condenser, through an outlet conduit 13. To this end, the illustrated valve mechanism 11 is a two- position 4-way valve which thus alternately pressurizes and depressurizes said second chambers of the piston and cylinder assemblies 10. The switching of the valve mechanism 11 between the pressurizing state for one assembly 10 and the depressurizing state for the other assembly 10 is carried out, as mentioned above, by means of the piston rod 8 (or piston 7) through any suitable transmission. As mentioned above, the fluid in said spaces of the pressure chamber and said first chambers of the piston and cylinder assemblies is oil. The pulser now described operates in the follow¬ ing manner. The pressure fluid source 12 pressurizes the piston and cylinder assembly 10 selected by the valve mechanism 11. The pressure is transmitted to the associated space in the pressure chamber 1 and is progressively built up so as to compress the spring 6 between the pistons 5 and 7 to such .an extent that the piston 5 is urged up on the lug 9a. This lug and the lug 9b connected to it are then pressed radially outwardly away from the spring compartment 2, such that the lug 9b is disengaged from the piston 7 which under the action of the energy potential built up in the spring 6 by the compression thereof performs a pulse stroke A forwards such that the piston 8 can perform a working stroke in/for its power engine. As mentioned above, the pulse stroke also switches the valve mechanism 11, by a suitable transmission, for pressurizing the other piston and cylinder assembly 10 and depressurizing the piston and cylinder assembly 10 previously pressurized, whereby the piston 3 moves in the opposite direction for building up an energy potential releasable as a pulse B, in the other spring 6. The first-mentioned spring 6, now relieved from pressure, then pulls its piston 7 in between the as¬ sociated lugs 9a and 9b and is stretched. Said trans¬ mission may be, for instance, a lever system adapted to be actuated by the lifting of the lever 9 as the piston 7 moves up on the cam lug 9b, and adapted to then displace the valve member, here a slide, of the illustrated valve mechanism 11. Thus, this construction is a double-acting genera¬ tor of high-energy pulses produced by low-energy poten- tials slowly built up in the pressure chamber 1. The following text will deal with an evaporator/ condenser system comprising the pulser I as above. The evaporator here is a solar collector and the energy pulses emitted by the pulser can be used e.g. for driving a ground water pump, for instance of the hy¬ draulic ram type. The system thus comprises a solar collector 15 which is connected to a condenser 16 by a conduit 12, 13 in which the pulser I (Fig. 1) is connected, which for pulse emission in the above-described manner is actuated by the working fluid, e.g. freon, evapo- rated in the solar collector. The working fluid is condensed in the condenser 16 by means of cooling liquid, for instance water w, whose inlet to the con¬ denser comprises a stop valve 17 and, downstream there¬ of, a control valve 18. The control valve is affected by the pressure in the condenser by means of a pressure sensor 19 in such a manner that an increasing pres¬ sure in the condenser entails increasing flow of cool¬ ing liquid. In the return conduit 20 from the conden¬ ser to the solar collector, there is connected a return pump 21 also driven by pulses which by a suitable transmission are derived from the pulses emitted by the pulser I. The energy is used to an increased extent if the working fluid to the condenser (in the conduit 13) is subjected to heat exchange with the working fluid from the condenser (in the conduit 20). In the return conduit 20 downstream of a non-return valve 22, there is further connected a pressure monitor 23 for the pressure in the solar collector, which monitor is adapted to close the stop valve 17 if said pressure falls below a predetermined value and to open the valve 17 when the pressure exceeds a prede¬ termined value. An auxiliary container 24 for compen¬ sating for leakage of working fluid is also connected to the return conduit over a stop valve 25 which is opened by a signal from a monitor 26 for insufficient pressure in combination with the set working tempera¬ ture in the evaporator. The system starts and stops fully automatical¬ ly, being controlled only by the supply of solar ener¬ gy to the solar collector. If the amount of solar energy supplied is not capable of building up the pressure in the pressure chamber 1 required for pulse release, the movement of the pistons in the pulser I is inter¬ rupted. If the pressure then drops, for instance because of a temperature decrease in the working fluid, a certain reversed movement of the piston 3 is had until _ a new position of equilibrium thereof has been obtained. When the temperature of the working fluid in the solar collector and, thus, the pressure therein increase again, the pistons will also resume their movement in the interrupted direction. The invention is of course not restricted to the embodiment of the pulser now described. Anyone of ordinary skill in the art realizes that means other than mechanical ones, such as pistons and springs, can be used for building up and releasing high-energy pulses, such as hydraulic and pneumatic means, and that the driving fluid for the pulser may be other than the working fluid in an evaporator/condenser system, that the pulser may be of the single-acting type (one spring 9 less powerful than the other), and that the piston and cylinder assemblies can be dispensed with, such that the working fluid will act directly on the piston 3. The pulser can be used for driving a pump, as stated above, in which case the pistons 5, 7 are con- nected to each other by means of rods and stops re¬ stricting the separation of the pistons 5, 7 to a predetermined spacing, but also for achieving e.g. high pressures in gaseous or aqueous media, for ob¬ taining high temperatures or obtaining electric pulses of short duration but of high intensity, these appli¬ cations being easily realized by the expert without any inventive efforts.

Claims: CLAIMS 1. Thermal pulser for converting low-quality thermal energy in a fluid into high-energy pulses, c h a r a c t e r i z e d in that it comprises a chamber (1) which is divided in a fluid-tight manner by a member (3) yielding to pressure and which on the respective side of the pressure-yielding member has an inlet (la') for a high-energy fluid whose energy content should be converted, and an outlet (lb 1 ) for a fluid having a lower energy content, said inlet and outlet being subjected to the influence of a valve device (11) for switching the inlet and outlet functions, the pressure-yielding member (3) communicating with a pressure accumulator (6) which is adapted in response to a fluid pressure increase on one side of the member (3) to build up, against the action of a bias (9c), a predetermined quantity of energy on the other side of the member (3) and, by suppression of said bias, release this quantity of energy as a short energy pulse. 2. Pulser as claimed in claim 1, c h a r a c ¬ t e r i z e d in that the pressure accumulator (6) is connected to the valve device for switching be¬ tween said inlet and outlet functions. 3. Pulser as claimed in claim 1 or 2, c h a - r a c t e r i z e d in that the pressure accumulator consists of a spring (6). 4. Pulser as claimed in claim 3, c h a r a c ¬ t e r i z e d in that the pressure-yielding member (3) is rigidly connected to the spring which has an abutment (7) on which the bias (9) acts. 5. Pulser as claimed in claim 4, c h a r a c ¬ t e r i z e d in that the spring (6) is disposed between and fixed on two pistons (5, 7), one (5) of which is connected by means of a rod (4) to the pres- sure-yielding member (3) and which are arranged for sliding in an extension of the chamber, two intercon¬ nected spring-biased cam means (9a, 9b) longitudi¬ nally spaced apart extending through the peripheral boundary wall of said extension. 6. Pulser as claimed in any one of claims 1-5, c h a r a c t e r i z e d in that it is of the double- acting type. 7. The use of a pulser as claimed in any one of claims 1-6 for operating a pump or other power engine by means of the working fluid in an evaporator/conden¬ ser system where the evaporator is a solar collector or means for recovering residual heat.

Inventors: WIGRAM STIG, WIGRAM, STIG
Applicants: WIGRAM STIG, WIGRAM, STIG
Application year: 1984
Main classification: F01K15
IPC codes: F01K25, F03G6