Isothermal pump with improved characteristics

Abstract

The pump has a body having a heat sink on the body underside. An extension rises from the body. A guide is provided for a piston, which together move up and down relative to the body and extension. The pump is within a tank filled with heating liquid. The heating liquid is separated (directly or indirectly) from a gas cavity with a bladder. The pump can have a coolant cavity partially bordered by a bladder that separates the heating liquid from the gas. A coolant then flows through the cavity over the top of the bladder keeping it cool and preventing bladder degradation. A high temperature liquid system maintains the temperature of the heating liquid. A coolant system maintains the temperature of the coolant. A pressure equalization system maintains balance in pressure between the heating liquid and coolant. A steam system is provided as is a control system.

Claims

1. An expansion device for expanding a gas, said expansion device comprising: a body having a gas inlet and a gas outlet; an extension, said extension fixed in position with respect to said body; a guide movable with respect to the extension; a piston, said piston fixed in position with respect to said guide; a bladder having an inner perimeter and an outer perimeter, said outer perimeter being between said body and said extension, and said inner perimeter is between said guide and said piston, said bladder separating a coolant within a coolant cavity from said gas within a gas cavity, wherein said coolant cools said bladder; and a heat sink connected to said body, wherein: said heat sink has heat sink interior transfer fins in said gas cavity and heat sink exterior transfer fins exterior of said gas cavity; and said piston has piston interior transfer fins in said gas cavity and piston exterior transfer fins exterior of said gas cavity.

2. The expansion device of claim 1, wherein said guide is movable with respect to said extension to determine the size of said gas cavity within said expansion device.

3. The expansion device of claim 1 wherein said coolant cavity is bordered by said bladder, said guide and said extension.

4. The expansion device of claim 1, wherein said coolant enters and exits said coolant cavity through said extension.

5. The expansion device of claim 4, wherein said extension has a first end wall lying in a first end wall plane, and a second end wall lying in a second end wall plane, two coolant inlets through said first end wall and being oriented between perpendicular and parallel to said first end wall plane, and two coolant outlets through said second end wall and being oriented between perpendicular and parallel to said second end wall plane.

6. An expansion device housed within a tank containing heating liquid, said expansion device comprising: a body having a gas inlet and a gas outlet; a piston movable with respect to said body; a gas cavity; a coolant cavity; and a bladder separating said gas cavity from said coolant cavity, wherein said bladder has a maximum operable temperature and a coolant flows through said coolant cavity to keep said bladder below said maximum operable temperature.

7. The expansion device of claim 6 further comprising: an extension, said extension fixed in position with said body; and a guide in a fixed position with respect to said piston, said guide being movable with respect to said extension.

8. The expansion device of claim 7, wherein said coolant cavity is bordered by said bladder, said guide and said extension.

9. The expansion device of claim 8, wherein: said bladder has an inner perimeter and an outer perimeter; said outer perimeter is between said body and said extension; and said inner perimeter is between said guide and said piston.

10. The expansion device of claim 7, wherein said coolant enters and exits said coolant cavity through said extension.

11. The expansion device of claim 7, wherein said extension has a first end wall lying in a first end wall plane, and a second end wall lying in a second end wall plane, two coolant inlets through said first end wall and being oriented between perpendicular and parallel to said first end wall plane, and two coolant outlets through said second end wall and being oriented between perpendicular and parallel to said second end wall plane.

12. The expansion device of claim 6 further comprising a heat sink connected to said body, wherein: said heat sink has heat sink interior transfer fins in said gas cavity and heat sink exterior transfer fins exterior of said gas cavity; and said piston has piston interior transfer fins in said gas cavity and piston exterior transfer fins exterior of said gas cavity.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic view of a system assembly incorporating an isothermal pump.

(2) FIG. 2 is a close-up partial schematic view of a pressure equalization piston at Top Dead Center.

(3) FIG. 2A is similar to FIG. 2, but instead shows the pressure equalization piston between Top Dead Center and Bottom Dead Center.

(4) FIG. 2B is similar to FIGS. 2 and 2A, but instead shows the pressure equalization piston at Bottom Dead Center.

(5) FIG. 3 is a perspective view of an isothermal pump.

(6) FIG. 4 is a side view of the isothermal pump illustrated in FIG. 3.

(7) FIG. 5 is an end view of the isothermal pump illustrated in FIG. 3.

(8) FIG. 6 is a top view of the isothermal pump illustrated in FIG. 3.

(9) FIG. 7 is a bottom view of the isothermal pump illustrated in FIG. 3.

(10) FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 5.

(11) FIG. 9 is a cross-sectional view taken along line 9-9 in FIG. 4.

(12) FIG. 10 is similar to FIG. 8 but shows the piston at Top Dead Center.

(13) FIG. 11 is similar to FIG. 9 but shows the piston at Top Dead Center.

(14) FIG. 12 is a partial side view as seen in Circle 12 in FIG. 4.

(15) FIG. 13 is a perspective view of a body.

(16) FIG. 14 is a side view of the body illustrated in FIG. 13.

(17) FIG. 15 is a top view of the body illustrated in FIG. 13.

(18) FIG. 16 is a bottom view of the body illustrated in FIG. 13.

(19) FIG. 17 is a perspective view of a heat sink.

(20) FIG. 18 is a side view of the heat sink illustrated in FIG. 17.

(21) FIG. 19 is an end view of the heat sink illustrated in FIG. 17.

(22) FIG. 20 is a bottom view of the heat sink illustrated in FIG. 17.

(23) FIG. 21 is a top view of the heat sink illustrated in FIG. 17.

(24) FIG. 22 is a perspective view of an extension.

(25) FIG. 23 is an end view of the extension illustrated in FIG. 22.

(26) FIG. 24 is a top view of the extension illustrated in FIG. 22.

(27) FIG. 25 is a bottom view of the extension illustrated in FIG. 22.

(28) FIG. 26 is a perspective view of a guide.

(29) FIG. 27 is a side view of the guide illustrated in FIG. 26.

(30) FIG. 28 is an end view of the guide illustrated in FIG. 26.

(31) FIG. 29 is a top view of the guide illustrated in FIG. 26.

(32) FIG. 30 is a bottom view of the guide illustrated in FIG. 26.

(33) FIG. 31 is a perspective view of a piston.

(34) FIG. 32 is a side view of the piston illustrated in FIG. 31.

(35) FIG. 33 is an end view of the piston illustrated in FIG. 31.

(36) FIG. 34 is a bottom view of the piston illustrated in FIG. 31.

(37) FIG. 35 is a top view of the piston illustrated in FIG. 31.

(38) FIG. 36 is a top view of a bladder.

(39) FIG. 37 is a perspective view of an alternative pump design.

(40) FIG. 38 is a side view of the pump design illustrated in FIG. 37.

(41) FIG. 39 is a cross-sectional view taken along line 39-39 in FIG. 38.

(42) FIG. 40 is a close-up parting schematic of an alternative pump design without a coolant liquid path.

(43) FIG. 41 is a schematic view of an alternative system assembly incorporating an isothermal pump.

(44) FIG. 42 is a chart of data.

(45) FIG. 43 is a chart of data.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(46) While the invention will be described in connection with one or more preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

(47) A system assembly 5 of the present invention is illustrated in FIG. 1. The system assembly 5 includes a pump 10, a tank 700, a high temperature liquid system 750, a coolant system 800, a pressure equalization system 850, a steam system 900 and a control system 1000. Each of these components are described below.

(48) The pump 10 is shown in FIGS. 2-12. The pump 10 preferably has a body 20, a heat sink 100, an extension 200, a guide 300, a piston 400, and a bladder 500. These components are described below in detail.

(49) The body 20 is seen in isolation in FIGS. 13-16. The body 20 has a top 30 with a perimeter 31 having holes 32 therein and an angled face 33. The body 20 also has a bottom 40 with a perimeter 41 having holes therein. The body 20 further has opposed ends 50 and 60, respectively. End 50 has a wall 51 with a gas inlet 52 therethrough. The gas inlet 52 is preferably in the middle of the wall 51 but can be located elsewhere without departing from the broad aspects of the present invention. End 60 has a wall 61 with a gas outlet 62 therethrough. The gas outlet 62 is preferably in the middle of the wall 61 but can be located elsewhere without departing from the broad aspects of the present invention. The body has sides 70 and 80. Body 20 also has a central opening 90.

(50) Turning now to FIGS. 17-21, it is seen that a heat sink 100 is illustrated. Heat sink 100 has a top 110, a bottom 120, opposed ends 130 and 140 and opposed sides 150 and 160. A central plate 170 is between the top 110 and bottom 120. The central plate 170 has a perimeter 171 with holes 172 passing through the central plate 170 near the perimeter 171. Interior heat transfer fins 180 are located on the top 110 of the heat sink 100. The interior heat transfer fins 180 each have a proximal end 181 and a distal end 182. Each interior heat transfer fin 180 tapers to a point at the distal end 182. In this regard, each interior heat transfer fin 180 is generally triangular shaped. In the illustrated embodiment, there are 31 interior heat transfer fins. However, it is appreciated that there could be more or fewer without departing from the broad aspects of the present invention. The interior heat transfer fins 180 are generally aligned parallel to each other. Exterior heat transfer fins 190 are located on the bottom 120 of the heat sink 100. Each exterior heat transfer fin 190 has a proximal end 191 and a distal end 192. The exterior heat transfer fins preferably have a uniform thickness between respective proximal ends 191 and distal ends 192 and they are preferably parallel to each other. In the illustrated embodiment, there are preferably 17 exterior heat transfer fins. However, it is appreciated that there can be more or fewer without departing from the broad aspects of the present invention. It is appreciated that the interior heat transfer fins 180 are generally aligned perpendicular to the exterior heat transfer fins 190 to provide extra rigidity.

(51) The entire heat sink including the interior and exterior fins can be constructed of a material with a high thermal conductivity such as copper or aluminum. By using a material with high thermal conductivity, heat from the liquid on the exterior of the pump can rapidly flow from the heating liquid to the exterior fins via convection, from the exterior fins to the interior fins via conduction and from the interior fins to the gas on the interior of the pump via convection thereby allowing for an isothermal expansion process. If the pump were to be used for compression, the flow of heat would be reversed.

(52) Turning now to FIGS. 22-25, it is seen that an extension 200 is illustrated. The extension 200 has a top 210. The extension 200 also has a bottom 220. The bottom 220 has several holes therein. An end 230 has a wall 231 with two coolant inlets 232 and 233 there through. An end 240 has a wall 241 with two coolant outlets 242 and 243 there through. Two opposed sides 250 and 260 are provided. The coolant inlets 232 and 233 are preferably angled towards sides 250 and 260 (i.e. diverging), respectively, on the inside of end 230 of the extension 200. The outlets 242 and 243 preferably are angled towards each other (i.e. converging) on the outside of end 240 of the extension 200.

(53) Turning now to FIGS. 26-30, it is seen that a guide 300 is illustrated. The guide 300 has a top 310 with an angled perimeter extension 311. The extension 311 has a proximal end 312 and a distal end 313. The extension further has an upper surface and a bottom surface 314. Guide 300 further has a bottom 320, two ends 330 and 340, and two sides 350 and 360. The guide 300 has a central opening 370. Several holes 380 are formed through the guide 300 interior of a perimeter of the central opening 370.

(54) Turning now to FIGS. 31-35, it is seen that a piston 400 is illustrated. Piston 400 has a top 410, a bottom 420, opposed ends 430 and 440 and opposed sides 450 and 460. A central plate 470 is between the top 410 and bottom 420. The central plate 470 has perimeter holes 471 formed therein from the top 410 that do not pass all the way through the central plate 470. Interior heat transfer fins 480 are located on the bottom 420 of the piston 400. The interior heat transfer fins 480 each have a proximal end 481 and a distal end 482. Each interior heat transfer fin 480 tapers to a point at the distal end 482. In this regard, each interior heat transfer fin 480 is generally triangular shaped. In the illustrated embodiment, there are 30 interior heat transfer fins 480. However, it is appreciated that there could be more or fewer without departing from the broad aspects of the present invention. There are also two end interior heat transfer fins 485 that are trapezoidal in shape (and having parallel respective outer walls). The interior heat transfer fins 480 are generally aligned parallel to each other. Exterior heat transfer fins 490 are located on the top 410 of the piston 400. Each exterior heat transfer fin 490 has a proximal end 491 and a distal end 492. The exterior heat transfer fins preferably have a uniform thickness between their respective proximal ends 491 and distal ends 492 and they are preferably parallel to each other. In the illustrated embodiment, there are preferably 14 exterior heat transfer fins 490. However, it is appreciated that there could be more or fewer without departing from the broad aspects of the present invention. It is appreciated that the interior heat transfer fins 480 are generally aligned perpendicular to the exterior heat transfer fins 490 to provide extra rigidity.

(55) The entire piston including the interior and exterior fins can be constructed of a material with a high thermal conductivity such as copper or aluminum. By using a material with high thermal conductivity, heat from the liquid on the exterior of the pump can rapidly flow from the hot liquid to the exterior fins via convection, from the exterior fins to the interior fins via conduction and from the interior fins to the gas on the interior of the pump via convection thereby allowing for an isothermal expansion process. If the pump were to be used for compression, the flow of heat would be reversed.

(56) Turning now to FIG. 36, it is seen that an isolation view of the bladder 500 is shown. The bladder 500 has a top 510, bottom 520 (seen in FIG. 2), ends 530 and 540 and sides 550 and 560. There are inner perimeter holes 570 and outer perimeter holes 580 formed through the bladder 500. The bladder 500 is preferably made of a thin (approximately 0.030″ thick) flexible high temperature silicone rubber that is medium soft (40 A) to medium (50 A) in hardness. A thin bladder is possible due to the fact that the pressure on the heating liquid side of the bladder will remain nearly equal to the pressure of the gas on the inside of the pump throughout the cycle. Therefore, as pressures are near equal on both sides of the bladder, a thin bladder can withstand very high pressures without tearing. Yet, it is appreciated that other materials can be used without departing from the broad aspects of the present invention.

(57) Returning now to FIGS. 2-12, the relationships of these various components of the pump 10 are illustrated. The heat sink 100 is connected to the bottom 40 of the body 20. Fasteners can be inserted through holes 172 and into holes 42 to secure the heat sink 100 in place forming an airtight seal (preferably with the use of a gasket). The interior heat transfer fins 180 project upwards towards the top 30 of the body 20 through the central opening 90 of the body 20.

(58) Holes 221 of the extension 200, holes 580 of the bladder 500 and holes 32 at the top 30 of the body 20 are aligned and fasteners are inserted therein to secure the extension 200 to the body 20 with the outer perimeter of the bladder 500 secured therebetween.

(59) Holes 471 of the piston 400 are aligned with holes 570 of the bladder 500 and holes 380 of the guide 300 and fasteners are inserted therein to secure the guide 300 to the piston 400 with the inner perimeter of the bladder 500 secured therebetween. The interior heat transfer fins 480 of the piston extends beyond the bottom 320 of the guide 300 through the central opening 370 of the guide 300.

(60) By having the exterior of the bladder 500 squeezed between the body 20 and the extension 200, and the interior of the bladder being squeezed between the piston 400 and the guide 300, the bladder effectively forms an impenetrable surface separating the gas from the coolant. Thus, the entire pump is hermetically sealed separating the gas within the interior of the pump from any exterior liquid.

(61) The angled perimeter extension 311 of the guide 300 can glide closely against the interior walls of the extension 200 so that the piston 400 reciprocates in a smooth linear manner with respect to the heat sink 100 while allowing for a very minimal amount of the heating liquid to commingle with the coolant. Further, interior heat transfer fins 480 of the piston 400 fully mesh with interior heat transfer fins 180 of the heat sink 100 at Bottom Dead Center to minimize gas volume within a gas or steam cavity 600.

(62) The pump 10 has both a gas cavity 600 in which the gas expands in and a coolant cavity 650. Coolant flows through the coolant cavity 650, which is bound by the bladder 500, the bottom surface 314 of the guide 400 and the inside walls of the extension 200. By having a coolant constantly flowing over the top of the bladder 500, the bladder can maintain its structural integrity as the pump operates at a much higher temperature. When the pump operates at a higher temperature a much higher Carnot efficiency can be achieved.

(63) Returning to FIG. 1, the tank 700 has a top section 710. Crank 715 is operable with a piston arm 720 connected to a head 725 that can move in a reciprocating linear manner within the top section 710. The tank has a body 730 with an interior 731 and an exterior 732. The pump 20 is housed within the body 730 of the tank 700.

(64) The high temperature liquid system 750 has a temperature gauge 755 (to measure temperature of heating liquid within tank 700), a gas inlet line 760, a gas valve 765 and a burner 770. The burner 770 is preferably located below the tank body 730 and is used to add heat to the tank to keep the heating liquid in the tank 700 at the desired temperature.

(65) The coolant system 800 has a heat exchanger 805 with a fan 806, an inlet line 810, an outlet line 815, and a coolant pump 820. The inlet line 810 is connected to coolant inlets 232 and 233 of the extension 200. The outlet line 815 is connected to coolant outlets 242 and 243 of the extension 200. The heat exchanger 805 is used to remove any heat absorbed into the coolant during operation of the pump 10. By having coolant liquid enter the coolant cavity 650 through inlets 232 and 233 and exit the coolant cavity through outlets 242 and 243, the bladder is evenly cooled during the expansion process.

(66) The pressure equalization system 850 is designed to accommodate changing volumes within the coolant cavity 650 as the piston 400 moves up and down. This change in cavity volume is clearly shown in FIGS. 2, 2A and 2B. The pressure equalization system 850 has an expansion cylinder 855. A pressure equalization piston with a piston head 860 is movably received within the expansion cylinder 855 and separates the heating liquid from the coolant. A high temperature liquid line 865 is provided as is a coolant line 870. The piston head 860 moves up and down within the expansion cylinder 855 in response to the piston 400 moving up and down relative to the body 20 as steam/gas is expanded in the isothermal expansion pump. The location of the piston head 860 within the expansion cylinder 855 is illustrated in FIGS. 2, 2A and 2B in relation to the location of the piston 400 relative to the body 20 in pump 10.

(67) The steam system 900 has a high-pressure reservoir 910 containing both liquid 911 and steam 912. A temperature gauge 920 is provided for measuring the temperature within the reservoir 910. An inlet line 930 (to the pump 10) with a valve 935 is provided. An outlet line 940 (from the pump 10) with a valve 945 is also provided. The steam system has a heat exchanger 950 with a fan 951 that removes heat Q from the steam causing condensation in a liquid return line 960. A liquid pump 970 forces the liquid to return to the reservoir 910. A gas inlet line 980 delivers gas to a burner 995. A valve 990 opens when the burner 995 is turned on so that the burner can supply heat to the reservoir to create high pressure gas/steam.

(68) The control system 1000 has a processor 1010. Several electric lines are provided. Line 1020 is an electric line to the gas valve 990 and burner 995 for the high-pressure reservoir 910. Line 1030 is an electric line to the temperature gauge 920 measuring the temperature within the high-pressure reservoir 910. Line 1040 is an electric line controlling steam inlet valve 935. Line 1050 is an electric line controlling steam outlet valve 945. Line 1060 is an electric line to temperature gauge 755 of the high temperature liquid system 750. Line 1070 is an electric line to the gas valve 765 and burner 770 of the high temperature liquid system 750.

(69) When the system is in operation, the processor can be programmed to operate the system at different temperatures and pressures. The processor will allow for the opening and closing of valves on both the inlet and outlet side of the pump thereby allowing a high pressure gas (which could be steam) to enter the pump, expand in volume and exit at a lower pressure. Work can be extracted from the system in the process. Further, the processor will operate the heating units that will add heat Q to the system and maintain designated temperatures throughout the operating cycle.

(70) One example of a cycle (data illustrated in FIGS. 42 and 43) would start with water as a saturated liquid at P1=1 bar and T1=99.67° C., a pump increases the pressure and temperature to P2=39.67 bar and T2=250° C., as a saturated liquid, requiring inputs of about W12=5 kJ/kg of work and Q12=660 kJ/kg of heat transfer. Phase change occurs in a boiler at constant pressure and temperature, requiring Q23=1715 kJ/kg of heat transfer with a work output of W23=−194 kJ/kg, resulting in a saturated vapor. This is followed by an isothermal expansion process (process 3-4) in the superheated region, from P3=39.67 bar to P4=1 bar, requiring Q34=1026 kJ/kg of heat input and producing W34=−894 kJ/kg of work. A condenser at 1 bar rejects Q41=−2557 kJ/kg of heat, requiring W41=241 kJ/kg work input, returning the water to saturated liquid at 1 bar (state 1). The thermodynamic efficiency of Cycle A is 24.8%. In this example, by having the waste heat rejected at 250 C, the waste heat (2557 KJ/kg) can be utilized to heat a building, a water tank or for a number of other purposes.

(71) Turning now to FIGS. 37-39, it is seen that an alternative pump 1110 is illustrated. Pump 1110 has a body 1120 and a heat sink 1130. The pump 1110 also has an extension 1200 with a top 1210, bottom 1220, an end 1230, an end 1240 and opposed sides 1250 and 1260. End 1230 has a wall 1231 with a coolant inlet 1232 that has one entrance and is split into two exits to split coolant flow. End 1240 has a wall 1241 with a coolant outlet 1242 with two entrances and one exit to combine coolant flow. The pump further has a guide 1300 and a piston 1310. Pump 1110 operates similar to pump 10 with the difference being the coolant flow is split into two portions inside the extension walls as opposed to exterior of the extension.

(72) Turning now to FIG. 40, it is seen that an alternative system assembly 1400 is illustrated having a pump 1410. The pump 1410 has a body 1500 with a top 1510 having a perimeter 1511 with an angled face 1512. The body 1500 also has a bottom 1520, an end with an inlet (not shown), an end 1540 with an outlet 1541. The pump 1410 further has a piston 1600 and a bladder 1610. In this alternative embodiment, there is no coolant cavity. The bladder 1610, which separates the heating liquid from the gas, is directly in contact with the heating liquid which leads to a rapid degradation of the bladder. The other option for maintaining bladder integrity would be to reduce the temperature of the heating liquid which in turn would reduce thermodynamic efficiency.

(73) Now, tuning to FIG. 41, it is seen that an alternative system assembly 1700 is illustrated. The system assembly 1700 has a pump 1710 (can be the same as pump 10), a tank 1800, a high temperature liquid system 1850, a coolant system 1900, a pressure equalization system 1910, a steam system 1920 and a control system 1930.

(74) The difference in this embodiment relates to the high temperature liquid system 1850. The high temperature liquid system 1850 has a reservoir 1855, a temperature gauge 1860, an inlet line 1870, a heat exchanger 1875, a return line 1880, a gas inlet line 1885, a gas valve 1890 and a burner 1895. The pump 1865 routes heated liquid through the heat exchanger 1875 that is located inside the tank 1800. The burner adds heat Q to the high temperature liquid system and pump 1865 routes heated liquid through the heat exchanger 1875 that is located inside the tank 1800.

(75) Thus, it is apparent that there has been provided, in accordance with the invention, an isothermal pump that fully satisfies the objects, aims and advantages as set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims.