Two fluid solar boiler

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TWO FLUID SOLAR BOILER surface is heated and expands, resulting in a convection

BACKGROUND OF THE INVENTION

current flowing upwardly, outwardly, and downwardly, and resulting in the upward flow of oil through the oil

Many devices have been proposed whereby solar en passageways; increasing the heat transfer to the hydro ergy is converted to perform useful work. The largest carbon fluid through the walls of the heat exchanger. emphasis in recent years has been on devices for di Pressurized hydrocarbon fluid produced in the heat rectly converting solar energy to electricity. These de exchanger is utilized to drive a fluid pressure motor. vices frequently comprise large panels of solar cells. The low pressure side of the fluid pressure motor is However, such devices are capable of converting only connected to condensors, which reduce the tempera a small fraction of the total available energy of the sun, O ture of the hydrocarbon to near ambient. A compressor and therefore require large areas to extract meaningful then forces the cooled hydrocarbon fluid back into the amounts of energy for most terrestrial purposes. Ac heat exchanger to complete the closed cycle. cordingly, they have seen application only where con It is therefore an object of the invention to provide ventional sources of power are unavailable; such as re a new and improved two fluid solar boiler. mote areas or in space. 5 It is another object of the invention to provide a new Other devices have been proposed whereby the en and improved solar boiler with high thermal efficiency. ergy of the sun is concentrated sufficiently to heat a It is another object of the invention to provide a new fluid to cause the fluid to expand sufficiently that an in and improved solar boiler than is usable in closed cycle creased pressure is produced, whereby a turbine or power systems.

comparable fluid pressure motor is operated. The effi It is another object of the invention to provide a new ciency of such a single fluid solar boiler has been suffi and improved solar boiler that produces high pressures ciently low that the devices are not practical for general without resorting to extreme temperatures. usage. Further, it has not often been practical to oper It is another object of the invention to provide a new ate such devices in a recirculating or closed cycle and improved solar boiler that utilizes a stable primary mode, which results in the utilization of considerable 25 heat exchange fluid and a volatile secondary heat ex quantities of the working medium. The final deficiency change fluid.

in such solar boilers of the prior art is that they have It is another object of the invention to provide a new utilized water as the working fluid, and thus require and improved solar boiler that heats a secondary heat raising water to a considerable temperature above am exchange fluid directly and through the medium of a bient before there is a pressure increase. primary heat exchange fluid.

It is therefore desirable to have a solar boiler capable Other objects and many attendant advantages of the of producing sufficiently high pressures in a working invention will become more apparent upon the reading fluid to operate a fluid pressure motor. Particularly of the following detailed description, together with the where such a device is susceptible to use in closed cycle 35 drawing, in which like reference numerals refer to like operations, and where the thermal efficiency of the de parts throughout, and in which:

vice permits the production of substantial quantities of FIG. 1 is a top plan view of a power system incorpo power from relatively small area. rating the solar boiler.

SUMMARY OF THE INVENTION FIG. 2 is a side elevation view of the system. FIG. 3 is an enlarged sectional view taken on line

An exemplary embodiment of the invention utilized 40 3-3 of FIG. 2.

a transparent lens to focus the solar light energy FIG. 4 is a sectional view taken on line 4-4 of FIG. through a primary heat exchange fluid and onto a heat 3.

absorber. The primary heat exchange fluid employed is Referring now to the drawings, there is illustrated a a substantially transparent oil so that the lens is able to 45 solar boiler according to the invention. A boiler con focus a substantial portion of the incident solar energy tainer 60 contains the light transmission lens 12, heat onto a curved heat absorbing surface. The heat ab absorbing means 14 and heat exchanger 16. The con sorber means, comprising the curved surface, is cov tainer 60 is filled with a quantity of primary heat ex ered with a black coating to absorb and convert a maxi change fluid comprising oil 22 which oil fills the lens 12 mum portion of the incident energy into heat, and raise and circulates throughout the container 60, through the temperature of the metal forming the heat absorber 50 holes 26 in the lens plate 24, passageways 18, in the surface. heat exchanger 16, and in annular passageway 70, sur The heat absorber means forms the upper surface of rounding the heat exchanger 16. A chamber 72 com a heat exchanger means. The heat exchanger means pensates for the expansion of the oil as it is heated. The comprising a plurality of vertical oil passageways in the 55 oil 22 is transparent, as is the lens plate 24, which al form of tubes communicating between a lower oil res lows for the light rays to pass through and fall upon the ervoir and an upper oil reservoir between the lens and heat absorbing surface 64 of the heat absorbing means heat absorber means. The chamber formed surround 14. The surface 64 is covered with a black coating to ing the oil passageways is filled with the secondary heat maximize the light absorption and conversion to heat. exchange fluid, which comprises a hydrocarbon that is 60 The heat exchanger 16 includes a casing 62 which en raised above its vaporization point by the temperatures closes the secondary heat exchange fluid of the inven produced in the solar boiler. tion, comprising a hydrocarbon CHCI F. This hydro The rate of heat flow from the oil to the hydrocarbon carbon is commercially available as FREON 21 and is is increased by inducing a thermal siphon action in the capable of operating at pressures to 1,400 psi. boiler container. The thermal siphon is produced by 65 Pressurized hydrocarbon is ducted from the heat ex the temperature created on the surface of the heat ab changer by conduits 28 which deliver it to a fluid pres sorber means adjacent the vertically upper ends of the sure motor 30. The fluid pressure motor may be of any vertical oil passageways. The oil in contact with this suitable type, such as a piston, turbine, or it may be of

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the rotary vane type such as is described in greater de reduce the temperature of the fluid to re-condense the tail in applicant's copending application entitled "Ro hydrocarbon fluid and permit it to be compressed into tary Vane Type Motor,' the contents of which applica a liquid by the compressor 50, which also raises the tion being hereby incorporated herein by reference. pressure of the fluid sufficiently to inject it into the en The pressurized hydrocarbon fluid is utilized to drive 5 vironment of the heat exchange container 62. the motor into rotation, which rotation is controlled by It should be noted that it is possible to provide auxili the power transmission mechanism 32. The removal of ary heating means in the form of a conventional burner energy from the high pressure hydrocarbon fluid results located in association with the boiler vessel 60 whereby in a reduction of its pressure. The low pressure hydro the heat of the sun may be supplemented or replaced carbon is exhausted from the motor 30 on lines 34 and 10 as necessary or desirable.

36. The exhaust lines 34 and 36 deliver the low pres Having described my invention, I now claim: sure hydrocarbon fluid to the dual primary condensers 1. A boiler for producing a source of high pressure 38 and 40, where a substantial portion of the remaining fluid from solar energy for use in association with a heat in the hydrocarbon fluid is removed. The fluid is closed cycle fluid pressure motor, comprising: then delivered via lines 44 and 46 to the secondary con 5 a chamber with a primary head exchange fluid, denser 42 where the remaining heat is removed, to re energy admission means for passing solar energy into duce the temperature of the hydrocarbon fluid to sub said chamber, stantially ambient. Line 48 returns the cooled hydro absorber means within said chamber and in combina carbon fluid to a suitable compressor such as the com tion with said primary heat exchange fluid for con presser 50, illustrated in the instant embodiment as 20 verting said solar energy into heat energy, being driven from the motor 30. This compresser sub heat exchanger means within said chamber for trans stantially increases the pressure of the hydrocarbon ferring heat from said primary heat exchange fluid fluid so that it may be re-injected into the heat ex to a secondary heat exchange fluid, changer on lines 52. said primary heat exchange fluid comprises substan 25 tially solar energy-transparent oil,

OPERATION

whereby said secondary heat exchange fluid develops

The apparatus is exposed to the sun's rays. The lens sufficient pressure to operate said fluid pressure 12 concentrates the rays of the sun and collects inci motor.

dent rays which have been scattered or reflected from 2. The boiler according to claim 1 wherein: the direct path to the sun. The collected and concen 30 said energy admission means comprises an oil-filled trated rays are then focused into the oil 22 which di lens that concentrates solar energy on said ab rectly converts a portion of the light energy into heat, sorber means.

thereby raising the temperature of the oil. Secondarily, 3. The boiler according to claim 1 wherein: the energy is focused upon the surface 64 of the heat 35 4.

at least one condenser is utilized to reduce the tem absorber 14. The black coated surface 64 absorbs a perature and volume of said secondary heat ex substantial portion of the remaining energy which change fluid.

raises the temperature of the metal making up the sur 4. The boiler according to claim 1 wherein: face 64. The high temperature metal of the heat ab said secondary heat exchange fluid comprises CHCI sorber serves several functions. A first function is F.

served by the direct transfer by conduction and con 40 5. A boiler for producing a source of high pressure vection to the oil 22 of a portion of the total heat en fluid from solar energy for use in association with a ergy. Secondarily, the interior of the surface 64 trans closed cycle fluid pressure motor, comprising, fers heat directly to the secondary heat exchange fluid a chamber with a primary heat exhange fluid, raising the temperature of that hydrocarbon fluid and 45 energy admission means for passing solar energy into increasing its volume and pressure. As a third function, said chamber, the elevated temperature of the surface 64 heats the oil absorber means within said chamber and in combina immediately adjacent the upper openings 90 of the oil tion with said primary heat exchange fluid for con transport tubes 18 to a temperature higher than that of verting said solar energy into heat energy, the oil generally. The heated oil in this vicinity is there 50 said energy admission means comprises an oil-filled fore made lighter than the surrounding oil and rises. lens that concentrates solar energy on said ab This results in the movement of oil up through the heat sorber means, exchange tubes in the manner of a thermal siphon. said absorber means comprising a curved black sur Thus, there is an enhanced heat exchange effect pro face having a first side in contact with said primary duced by the circulation of the oil up through the tubes 55 heat exchange fluid and a second side incontact and then down around the heat exchange container 62 with said secondary heat exchange fluid, through the passage 70. This results in the heat ex heat exchanger means for transferring heat from said changer transferring heat to the hydrocarbon fluid, fur primary heat exchange fluid to a secondary heat ther raising its temperature and pressure. Since the exchange fluid,

FREON 21 utilized expands greatly when heated, this 60 whereby said secondary heat exchange fluid develops produces a high internal pressure which is then con sufficient pressure to operate said fluid pressure veyed via the lines 28 to the intake manifold or compa notor.

rable apparatus of the motor 30. The high pressure 6. A boiler for producing a source of high pressure fluid is utilized in driving the motor, and by the removal fluid from solar energy for use in association with a of energy through the rotation of the motor the fluid is 65 closed cycle fluid pressure motor, comprising: reduced in pressure and temperature and exhausted on a chamber with a primary heat exchange fluid, lines 34 and 36 to the condensers. The primary con energy admission means for passing solar energy into densers 38 and 40 and secondary condenser 42 further said chamber,

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absorber means within said chamber and in combina said passageways terminating at their upper ends ad tion with said primary head exchange fluid for con jacent said absorber means, verting said solar energy into heat energy, and passageways and said absorber means forming a heat exchanger means for transferring heat from said thermal syphon to increase the heat flow through primary heat exchange fluid to a secondary heat said heat exchanger, exchange fluid, whereby said secondary heat exchange fluid develops said heat exchanger means comprising a plurality of sufficient pressure to operate said fluid pressure vertically extending passageways for said first heat notor.

exchange fluid,