WO2017133294A1 - Tapering spiral gas turbine with homopolar dc generator for combined cooling, heating, power, pressure, work, and water - Google Patents

Abstract

A tapering exponential spiral for a gas expander (503) for work extraction or air cooling is used. This tapering exponential spiral could also be used for a gas compressor (501) to increase the pressure and temperature of air. The compressor-expander forms a single and simple structure for easy manufacturing. A simple formula for temperature drop across a tapering exponential spiral for adiabatic expansion of air is derived. The pressure increasing as air is compressed outside in for isothermal compression of air is also derived. The spiral is proved efficient for energy conversion. The Faraday homopolar DC generator by changing its geometry and technology is improved. High work to electricity conversion efficiency and high voltage and power production are achieved. The same generator structure can be used as a homopolar DC motor. By controlling voltage, the speed of the motor or generator is controlled. By controlling current, the torque force used or produced is controlled. The homopolar generator and motor can be easily integrated with the spiral compressor and expander. Three applications using these basic inventions are proposed. First a heat turbine powered by concentrated solar energy or by burning gaseous fuel is proposed. Second, a heat pump powered by electricity for cooling, refrigeration, and heating of water is proposed. Third, a method to desalinate water by solar power, using concentrated sunlight to evaporate salty water under reduced pressure is proposed. The Firefly technology can provide small scale, local, and simple production of energy of many kinds, giving solar power back to the people where and when needed.

Description

TAPERING SPIRAL GAS TURBINE WITH HOMOPOLAR DC GENERATOR FOR COMBINED COOLING, HEATING, POWER, PRESSURE, WORK, AND WATER

CROSS REFERENCE TO RELATED APPLICATION

The present application includes subject matter disclosed in and claims priority to a provisional application entitled "A Tapering Spiral Gas Turbine for Combined Cooling, Heating, Power, Pressure, Work, and Water" filed February 2, 2016 and assigned Serial Number62/290,393 describing an invention made by the present inventor.

BACKGROUND OF INVENTION

[0001 ]The world needs clean air, water, food, energy, and transportation that is accessible and equitable to all, not just for the developed countries. Key to universal provisioning of these amenities is technological advances that meet these needs of people where they are, supported by energy sources that are local and affordable, such as solar power and bottled liquid petroleum gas.

[0002]We are facing global climate change due to the burning of fossil fuel causing global warming and rising of sea level. Burning coal creates air pollution. Ground water is rapidly depleted. Global warming brings extreme heat, and air conditioning uses more global warming fossil fuel . Transportation requires expensive petroleum product, causing chronic particulate pollution in major cities.

[0003]To mitigate energy shortage and climate change, we emphasize three shift of focus. The first shift of focus is from energy generation to energy application. Energy generation is just a mean to the end comforts of clean air, water, food, and transportation. Energy conservation often brings more comfort.

[0004]The second shift of focus is from electricity to heat. We can use heat directly for space and water heating, and indirectly to generatecooling, water, cooking, motion, and then motion-induced electricity. Electricity is generated for lighting, communication, computation, and electric transportation.

[0005]We should store energy close to the form it is used: heat energy in heat bath, pressure energy as pressurized gas, chill as condensed refrigerant or frozenmatter, and electrical energy in chemical batteries. If small and efficient turbines are available, we should store chemical energy as fuel.

[0006]The third shift of focus is local generation, storage, conversion, and use of energy. We want to reverse the Edison utility model of centralized generation (CG) of electricity with grid distribution.

[0007]We inventedtechnologiesthat integrate a micro-turbine with a micro DC generator. We call that Firefly technology, which is personal yet as efficient as large power plants. CG becomes unnecessary and is replaced by Personal Energy (PE) for mobile collection, storage, conversion, and use of energy.

[0008]PE replacing CG brings us full circle in 4 phases of industrial revolutions. The 1^st revolution centralized work production by large steam engines. The 2^nd revolution electrified the world with large AC generators driven by steam engines. The3^rdrevolution of micro-electronics gave us global computing and communication networks. The 4^th revolution of MEMS (Micro-Electronic-Mechanical Systems) reverses the 1^st and 2^nd revolutions of CG to give us PE, making all things local, small, and personal.

[0009]Firefly has 10S: Smart, Small, Simple, Scalable, Savings, Strong, Silent, Safe, Stores, and Stylish. Firefly provides Combined Cooling, Heating, Power, Pressure, Work, and Water (acronym CCHP²W²). [0010]Firefly can help industrialize poor countries, allowing people to be productive where they are without electric or water grids. Half of the world lives without reliable electricity or running water supply.

[0011]Key to CCHP²W² is an efficientmicro-turbine powered by concentrated solar power or internal combustion of gaseous fuel.lntegrated with the micro-turbine is an efficient micro DC motor-generator.

[0012]Let us survey the history of heat engines and electric generators. Hero of Alexandria invented the first heat turbine 2000 years ago. Steam produced in a boiler was ejected through nozzles in opposing directions, turning the hinged boiler. The Hero turbinewas a curiosity exhibited in the Alexandria Library.

[0013]ln between Hero and the 1^st industrial revolution, wind and water motion energy were harvested by means of turbines, literally a rotating device such as a wind mill or a water mill. Blades or buckets obstruct wind or flowing water, spinning the turbine to extract mechanical work.

[0014]The first powerful and practical steam engine was patented by James Watt in 1769. Steam from coal fired boiler drives a piston in a cylinder to give a significant force for pumping water, weaving textile, and driving train. Steam driven locomotives brought people to cities. Centralized manufacturing was driven by steam engines. These Rankine cycle heat enginesboil a liquid to create pressure to do work.

[0015]The Stirling engine was patented by Reverend Stirling in 1816. He was concerned with the deadly pressure of steam boilers. Stirling engines use two cylinders, one for heating air and another for cooling air. Expanding air performs work. These Carnot cycle heat engines operate at high temperature.

[0016]Around 1830, Michael Faraday invented the homopolar disk generator. Electric current is collected from the perimeter of a rotating disk sandwiched between poles of a C-shaped magnet. Lossy eddy current flows within the rotating disk. Despite improvements such as that by Nicola Tesla, this generator was not used for utility power generation due to low efficiency and voltage.

[0017]lnventions of Edison and Tesla created the power utilities in the early 20^th century. Coal fired steam engines generate electricity by Tesla's AC generators. Steam engines are large and inefficient. They are strong but slow. To generate large current, AC generators require large electromagnets.

[0018]Nikola Tesla invented the 3 phase electricity generator with mutual induction of current in stator and rotor coils. Ease of voltage conversion allows efficient high voltage transmission of electricity over long distance electric grid with much reduced ohmic loss of power. Power utilities adopt AC over DC .

[0019]Nikola Tesla also invented the Tesla turbine. The turbine comprisesa stack of closely spaced disks. Steam is injected tangentially on turbine periphery. Steam spirals inwardin between disks towards the center of the stack. Steam drags disks by gas viscosity. Tesla claimed to achieve 90% isentropic efficiency of theoretical Carnot cycle efficiency, which is not verified even with today's technologies.

[0020]Since 1950, gas and steam turbines have made power utilities much more efficient. Steam turbines powered by steam generated by burning coal have efficiency around 40%. Large amount of water is required to condense low pressure steam from the steam turbine. Combined cycle gas turbine(CCGT) achievesefficiency above 60%. CCGT uses natural gas to drive a Brayton cycle gas turbine. Hot gas exhaust generates steam to power a Rankine cycle steam turbine.

[0021]Since the 21^st century, the world confronts pollution from burning fossil fuel. The resulting climate change is threatening human survival. Yet much of the world population remains poor for being served water, heat, chill, food, and transportation. CG is failing poor countries that lack power infrastructure. Yet poor people suffer the most from global warming, rising sea levels, and chronic air pollution. [0022]Burning more coal is not the answer to help people live a comfortable life. We cannot afford to build expensive, polluting, and wasteful infrastructure of energy collection, generation, and distribution. Natural gas and solar power are our energy source of choice for PE. Both are abundantly available for personal energy generation and use. PEis efficient, clean, local, small, useful, and therefore beautiful.

[0023]To solvethe energy and environmental crises, we have to personalize energy production, storage, conversion, and usage. We will focus on heat as our energy source. Heat can come from solar thermal, geothermal, or from burning of piped natural gas and propane transported in canisters.

[0024]Our goal is to make small gas turbines as efficient as large gas turbines, at a small fraction of cost per Watt of power. We want cogeneration of heat, chill, water, and work besides electricity.

[0025]We want to find the right geometry of open gas flow that allows gradual release of gas pressure to produce work. We want to avoid a sudden conversion of pressure into kinetic energy of the gas.

[0026]We also want to re-invent the Faraday homopolar DC generator using modern magnets and solid state electronics. We have discovered a new geometry for motion induced electricityto solve the century old problem of poor efficiency and low voltage of Faraday's generator.

[0027]We propose three applications based on our invention of micro-turbine and micro-homopolar generator. First, we describe a heat turbine that integrates the spiral compressor, the spiral expander, and the homopolar DC generator. This Firefly heat engine generates work or electricity.

[0028]This micro-turbine can be used to drive cars, directly powering the drive train or indirectly with its electricity generated. The turbine can be modified as a turbo charger for automobile piston engines, using tailpipe exhaust to turn a spiral expander which then drives a spiral compressor to increase engine pressure. Firefly can also be used to fly drones. Firefly can power homes off grid by solar and gas energy.

[0029]The second application is a heat pump of a spiral compressor of air driven by the homopolar DC motor to compress air. Heat of compression is used to heat water. Compressed air when cooled gives out water. Compressed air when expanded gives dry and cool air for air conditioning and refrigeration.

[0030]Third, we describe a solar powered water desalination system. Solar energy boils salty water under reduced pressure. Solar energy drives a spiral compressor to condense steam. This desalination system has high efficiency as heat of condensation is reused for evaporating more salty water.

SUMMARY OF INVENTION

The tapering exponential spiral is discovered as an effective geometry for gas flow for the conversion of the internal energy of pressurized and hot gas into motion energy. We solved the temperature and pressure drop of adiabatic gasflowin the spiral outwardly, pushing the turbine to yield motion energy.

The same exponential spiral when turned in reversed rotational direction can be an effective geometry for compression of gas, converting motion energy into pressurized and heated gas. We solved the pressure gain of gas that is compressed isothermally by the spiral wall pushing gas toward the center.

The Faraday homopolar DC disk generator is improved to solve the problems of lossy current circulation within the disk and low voltage induced. The new DC generator uses a ring of permanent magnet as the rotor. The magnetic ring has the same magnetic pole (hence the term homopolar) to induce current on a ring solenoid acting as the stator coil. The induced voltage is a product of the magnetic field strength, the velocity of the rotor rim, the number of turns in the stator coil, and the height of the stator coil.

We integrate the spiral compressor and spiral expander with the DC generator and motor to invent systems for three applications.

The first application is a heat turbine that can convert solar or gas combustion heat into work and electricity. This heat turbine can be used to drive vehicles such as cars, bus, trucks, trains, and small aircrafts by its motion and electricity generated from heat conversion.

The second application is a heat pump that powered by a DC motor to compress humid air to higher temperature and pressure. The compressed air is cooled at room temperature to remove heat and humidity to produceheated water andmoisture condensed potable water. Cooled and dried compressed air can expand in the spiral expander to yield work and cold air for air conditioning.

The third application is a solar water desalination system. Focused sunlight heats salty water to boil in reduced pressure at a lower than 100°C temperature. Low pressure steam at head of the heated water column is compressed by the spiral compressor using solar generated electricity.Condensing higher pressure steam exchanges its heat of compression and condensation to further heat the salty water column, generating more low pressure steam for even more potable water. Potable water is collected at the bottom beneath the column of evaporating salty water.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031]Fig. 1 shows a tapering exponential spiral

[0032]Fig. 2 shows gas temperature drop ratio T/T₀ versus radius rand the Brayton cycle

[0033]Fig. 3showsgas compression ratio p₀/p versus radius r and the Hui cycle

[0034]Fig. 4 shows the geometry of a DC homopolar generator and motor

[0035]Fig. 5 shows vertical view of turbine and generator cross section (center) and horizontal cross section views of expander (top spiral disk) and compressor (bottom spiral disk)

[0036]Fig. 6shows cross section view of a heat pump for heating water and air conditioning

[0037]Fig. 7shows cross section view of a solar powered desalination system using spiral compressor

[0038]Fig. 8 shows a parabolic conic mirror concentrating sunlight onto a water column at the focal line

[0039]Fig. 9 show a scrolling compressor in open (when spirals are closest together, top picture) and closed positions (when spirals are farthest apart, bottom picture). Pockets of air are in between spirals.

THE TAPERING EXPONENTIAL SPIRAL

[0040]Traditional means to compress or expand a gas predominantly use two devices: piston or fan blades. Gas is enclosed in a cylinder with a movable piston to compress or expand the gas. Gas can also be impinged upon by high speed rotating blades for imparting or harvesting kinetic energy of gas.

[0041 ]We 3D printed turbines to find the appropriate geometry of spiral gas flow channel. We changedspiral size and shape. We tried the Archimedes spiral with radiusr = αθ + hat increases linearly as turn angle 0. Testing with pressurized gas showed that the Archimedes spiral did not work well.

[0042]We also tried the exponential spiral, also known as the Bernoulli spiralnamed after its inventor. Spiral radius r = ae^M increases exponentially as the angle Θ. Fig. Ishows an exponential spiral.

[0043]Exponential spiral occurs often in nature such as seashells and plants. Fluid dynamics gives rise to an exponential spiral shape for hurricanes. Galaxy arms are exponential spirals. The exponential spiral results from the physics of growth. Growth is often self -generating and self-similar.

[0044]The exponential spiral is self-similar: the spiral looks similar as we zoom into the center of the spiral. A spinning Bernoulli spiraldoes not appear visually contracting or expanding.

[0045]This self-similarity is due to an important property of the Bernoulli spiral: spiral tangent makes a constant angle with spiral radius. Gas flowing in the Bernoulli spiral pushes against spiral wall at a constant angle. In contrast, the Archimedes spiral pushes against spiral wall with diminishing angle.

[0046]An eagle circles and zooms in on a preyin a similar manner. The eagle fixes its eye on the prey. The line of sight of the eagle towards the prey is at a fixed angle. Distance of eagle from prey decreases logarithmically as the eagle turns. This logarithmic spiral is the inverse of the exponential spiral. [0047]Exponential spirals have radius r = ae^be where Θ is thepolar angle in radians. Logarithmic spirals havefl = -ln - We will use the relation— = abe^ou = br for chanqe of variable from Θ to r.Spiral b a άθ ³

tangent makes a constant angle a = tan^"1 (-) with the radius. Spiral length from r = a is x =

cos (a)

[0048]Fig. 1 shows a spiral with outside wall that is an exponential spiral. The width between the outside wall and the inside wall is shown to be tapering.Spiral channel width decreases exponentially as angle Θ. We will show that this tapering is key to retaining gas pressure without rapid speeding up of gas.

TEMPERATURE CHANGE FOR ADIABATIC EXPANSION OF A GAS IN A TAPERING SPIRAL

[0049]We give simple solution of gas temperature as gas expands adiabatically (meaning without heat exchange with the surrounding) in the tapering exponential spiral. This simple solution is key to our invention. We can prove by theory the efficacy of the tapering exponential spiral. Close form solution for gas temperature for modern gas turbine is sorely missing.

[0050]Early on, we experimented with pressurized air driving a long spiral of narrow constant width. The turbine was spinning fast but produced little torque. Torque force is important for work production.

[0051]Torque is produced by pressure force. To maintain better control of pressure release, we consider varying the bore area A = wd, the width wtimes depth dof the spirals. Gas speeds up due to its internal pressure gradient as dictated by Navier-Stokes equation. Tapering prevents gas speed up because of gas constriction. We will show that this tapering bore moderates pressure release.

[0052]A tapering spiral allows an exploding gas to exert a larger torque on the outside spiral wall, which is longer than the inside wall. Besides a larger surface area, the outside spiral wall also has a larger radius than the inside spiral wall. This larger surface area and radius of the outside spiral wall give a larger torque force than the opposing torque acting on the inside spiral wall.

[0053]A high pressure and hot gas moving inside the spiral has two main components of energy. The first component is gas internal energy due to heat, which is the chaotic motion of gas molecules.

[0054]The second component is gas kinetic energy, which is the systematic velocity of gas. At the center of the spiral where a high pressure gas is heated, gas internal heat energy is high. Gas velocity is low.

[0055]Most micro-turbine designs use a nozzle to release immediately gas pressure, converting the internal energy of gas instantaneously into kinetic energy. Gas cools rapidly. Post nozzle, the high speed gas rapidly becomes turbulent. High speed gas makes impact on turbine blades, producing very little torque force. Most kinetic energy of the gas is converted back into heat, not work.

[0056]We strive not to reduce gas pressure suddenly. We use pressure force of high temperature gas with retained pressure to produce a significant torque force at low angular velocity of the turbine. Nozzle driven turbines give little torque force and spin the turbine at extremely high speed.

[0057]Gas kinetic energy plays a minor role in energy conversion in our turbine as explained by Bernoulli's law. Bernoulli law states that the energy density of a gas comprises two components. The first component is pressure, which has unit of energy per unit volume. Pressure p is the internal thermal energy density of a gas. This results from the ideal gas law withp =

[0058]The second component is kinetic energy density^ pv² where p is the mass density of the gas and v its velocity. By preventing sudden pressure release and gas speed-up, we keep this component small. [0059]Bernoulli's law states that the sum of these two components p + -pv² is constant. For our turbine, we keep pressure high, say at 10 bars or 1 million Pascals. For gas of density p ~ 1 kg/m³ moving at high velocity^ = 100m/s, gas kinetic energy density ^pv² ~ 5,000Pa « p = l,000,000Pa. If 10 bars of pressure is released suddenly to 1 bar, gas velocity would go supersonic beyond 1000m/s.

[0060]ln our design, we prefer to taper the depth of the spiral channel instead of its width. Fig 5shows an expander at the top of the turbine that is conic in shape. We decrease bore area^4 = wd by reducing depth d while keeping constant width w as shown in the expander cross section.

[0061]We consider the torque produced by pressure acting on turbine walls. Torque is pressure p times τδθ 1

spiral wall area— -d times the leverage of the torque r cos a, where tan a = -. Net torque is the difference between the greater torque force on the outer wall of the channel than its inner wall. We assume constant pressure across the narrow width of the spiral.

[0062]Torque is pressure times area times leverage. Net torque between the outside and inside walls is

( τδθ \ ( [r - w]S6 \ _r

5T„ = p x—— x d x r cos a — p x _: x d x [r— w\ cos a = pbwd [2r— w\ δθ p I ana / sm a J

[0063]For a turbine rotating at angular velocity ω, this differential torque produces a differential power:

— - =— -ύύ = pbwd [2r— νν]ω = pbA [2r— νν]ω

du du

[0064]The derivation of power extraction from gas is simplified by the following assumptions. We ignore the kinetic energy component of Bernoulli's law. With low speed, we ignore viscosity of gas flow. We assume a fast spinning spiral that pressure force is expended as work rather than used to speed up gas. We also assume a constant pressure and velocity of gas across the radial width of the thin spiral channel.

[0065]We now consider power flow of gas inside the spiral. Consider the pressure energy component Pf of gas flow. Pressure power flow across area^4 of a gas flowing with velocity u is Pf = Aup.

[0065]By conservation of energy, power loss P^ is power gain by the turbine P_p. Therefore

[0067]Conservation of mass flow implies constan up. Dividing above equation by Aup gives

^-f ) ₊ f ) ^. _b [2r - _w] = 0

do pj pj u

[0068]Change of variable from Θ to r using the relation— dr pj pj u L r J

[0069]From ideal gas law pV = nRT, we have

p nRT RT

T

p pV pV/n Molar mass m_w is the weight of a mole of gas. Thus p/p measures the temperature of gas.

[0070]With these substitutions, we obtain the remarkably simple differential equation

dT ω r w-

— + 7- 2 = 0

dr u L r ^J

This equation is independent of the nature of gas used. The first term is heat energy loss of gas across the radius. The second term is work gain by turbine.

[0071]We assume that gas flow is adiabatic, implying constant TV^r~1. Gasvolume V is proportional to Au of gas flow velocity u across area A. Thus r(i4u)^y_1 = TO G O)^7-1, giving

dT TY^{/ {}V- A r iv-

— + ω 2

dr T₀ ^{R > A₀u₀ i r [0072]We choose J4 = wd with constant w and changing depth d = d₀ ^{1 cr} , a linear tapering of depth

1— cr₀

versus radius r of the channel. Note d = d₀for r = r₀. Since radius and length of the spiral channel increase exponentially as angle Θ, channel depth ddecreases exponentially as channel length x =

[0073]With this channel eometry we obtain the differential equation

The initial condition is by T = T₀ when r = r₀. The solution of the differential equation is

1 -(y-l)

ω

T 1 + (2 + cw) (r— r₀)— c(r²— r₀ ²)— w in—

γ - 1 (1 - cr₀)u₀ r₀-

[0074]Fig. 3is a plot of temperature Γ/TOdropping across turbine versus radius r₀ = l cm≤ r≤ r = 4cm for ratios— of 0.2, 0.4 0.6, 0.8, and 1.0. We choose r₀ = 1cm, d₀ = 2cm, maximum spiral radius r = 4cm, c = 0.2, w = 0.3cm, and γ = 1.4.

[0075]Efficiency ss = 1 -— , with T_H = T₀ the high post combustion temperature and T_L the low exit

^TH

temperature of gas. At— = 1.0, efficiency is as high as 60%. At ω = 377 rad/s (60Hz), u₀ = 377cm/ s, a breezy speed (less than 15 kilometers per hour). Gas cools from l OOO C to 400/e (127°C).

PRESSURE CHANGE FOR ISOTHERMAL COMPRESSION OF A GAS IN EXPONENTIAL SPIRAL

[0076]We repeat the above analysis for isothermal compression instead of adiabatic expansion of gas in the previous section. This analysis is crucial for understanding the performance of heat pumps, for which isothermal processes improve the efficiency of heat or chill production.

[0077]Thermal energy can be exchanged between the working gas and the environment. For isothermal processes, there is no change of internal energy of gas¾_as = anRT for constant gas temperature T. For air, a = 2.5, which is the degree of freedom of the gas molecules (namely 5) divided by 2. dT

[0078]For isothermal processes with constant T, the first term— = 0 in the differential equation for adiabatic processes— + T— 2 -— = 0. Work done for the term T— 2 -— is heat transferred to the dr u L r J u V r \

environment. For isothermal processes, heat transfer is AQ = W_T = nRTln ^. The differential equation of isothermal gas flow reduces to the following equation:

ω r w T dp

T— \ 2 +—— - = 0

u L r J p dr

[0079]For isothermal processes, pV = nRT is constant for constant T. Velocity u satisfies the condition X at Aup = A₀u₀po is a constant for given valueSi4₀, i½, Po The above differential equation becomes:

dp A ω 1 r w

— = -_Λ 2 - - dr

p² A₀ u₀ po L r J

[0080]Solving the above differential equation with similar tapering factor c, we have the pressure ratio:

E£ _{= 1} (2 + cw) (r— r₀) — c (r²— r₀ ²) — w in— p (1 - cr₀)u₀ r₀-

Fig. 3plots pressure ratio for r in the range r₀ = 2cm≤r≤r = 16cm for ratios— =0.05,0.10, 0.15, 0.20, 0.25. We choose tapering with c = 0.025(d₀ = 4.5cm≥d≥ d = 3cm)and widthw = 1cm.

[0081 ]The unknown exit velocity u₀ is determined by pressure at the two ends of the spiral, namely p₀ and p . Velocity u₀ will adjust to become the solution of the above equation for given— .

Vi

[0082]Pressure increases linearly as the angular velocity w and compressor radius. Compression increases as flow velocity u₀slow, as the same work is done on a smaller volume of gas flow.

[0083]Flow velocity u₀is related to rim flow velocity i½ by the conservation of flow equation ₀ι½ρ₀ = Aup for isothermal compression. Substituting— = -^— into the pressure ratio equation:

1— cr ω

u₀ = u^■ (2 + cw) (r— r₀)— c(r²— r₀ ²)— w in—

1— cr₀ 1— cr₀ r₀-

[0084]Forc = 0, we have simplyu₀ = u— ω 2 (r - r₀) - w in— . Gas flow towards the center slows

L r₀J

down by increasing coor radius r. Compression increases as gas flow slows down.

[0085]Tapering bore can increase compression ratio. Another method to achieve a high compression ratio is to compressair in multiple stages. Stages of spiral compressor can be manufactured by 3D additive printing. High compression ratio exceeding 20 is necessary for high efficiency heat engine.

[0086]Air conditioning and solar desalination can use a compression ratio that is as small as 2, for which our spiral compressor can be effective without spiral tapering or using multiple spiral stages.

A NEW DC H0M0P0LAR MOTOR GENERATOR AND MOTOR

[0087]Heat pumps employ work to move heat from low temperature to high temperature. Motive force can be provided by an electric motor.Heat engines convert heat to work. Motive force is turned into electricity by an electric generator. We embarked on a redesign of electric generator and motor. Pioneers such as Edison, Tesla, and Steinmetz were frustrated by technology available then.We can do better now redesigning generators with modern technology, making them small and efficient.

[0088]The first electricity generator was demonstrated by Michael Faraday around 1830. The Faraday homopolar DC disk generator was inefficient. Three major technology deficiencies then are identified here. The geometry of Faraday's invention was also at fault.

[0089]The first problem was the lack of strong permanent magnets. Lacking strong permanent magnets, Faraday and Henry had to use insteadlarge electromagnets for induction of motion or electricity. The second problem was the lack of high speed heat engines such as the modern gas turbine. Magnets have to be strong to convert the slow but large torque of steam engines. The third problem was the lack of solid state electronics for digital and solid state control of voltages and currents. Voltage control by induction coils and transformers is cumbersome.

[0090]Modern technology solved these problems. We have rare earth magnets with strong magnetic field strength. High speed turbines run much faster than piston steam engines. Solid state high power electronics provides flexible control of voltage and current. We re-invent the homopolar DCgenerator integrated with our turbine. The generator is small with higher power and voltage than Faraday's. No brush or commutator is needed. Efficiency is high with no eddy current and magnetic hysteresis loss.

[0091 ]We adopt the new DC generator as part of the Firefly technology. We believe that DC is more useful than AC for LED lighting, motoring, as well as charging batteries. Digital control and solid state electronics allow easy change of DC voltage and current over time. There is no need to invert DC into AC, such as that needed for grid tied solar panels to change solar generated DC into grid AC.

[0092]We explain our generator by the Space Tether Experiment done onboard the Space Shuttle in 1996. A 2 km long metallic core tether tied the Space Shuttle flying eastward in a low equatorial orbit to a small satellite further out. Current generated was 1A before the Teflon coated tether developed a pinhole leak of that current onto the ionosphere, melting the tether and resulting in loss of satellite.

[0093]Earth's magnetic field of about 25 micro-Tesla at equator points north, cutting through the tether at orbital speed of 10km/s. Electrons flowed inwards to Space Shuttle and then leaked to the ionosphere there. Voltage generated was F = E. d = \v\ \B\d = 10,000m/s x 0.000025Γ x 2000m = 5000volts. The tether broke where voltage relative to the satellite end was 3500roZts, closer to the Shuttle end. The high voltage of 3500volts broke through the Teflon barrier with electrons jumping through the ionosphere onto the Space Shuttle for further dissipation into the surrounding ionosphere.

[0094]The Space Tether Experiment can also be a motor to propel the Space Shuttle to higher orbit by driving a current through a stiff tether to generate an electromotive force to push the Space Shuttle forward. This forward pushing can lift the Space Shuttle into a higher orbit. Compared with the generator, a much shorter and stiff push rod, a much higher current flow, and multiple rods may be needed for the motor. A figure 8 wiring between ends of two parallel rod is needed for circuit closure.

[0095]Our homopolar DC generator has similar geometry. We consider the Space Shuttle as stationary relative to the rotating earth, namely that Earth is the rotor while the Space Shuttle becomes the stator. We use a rotating disk magnet with south pole pointing axially downward. The rotating magnetic field creates an electric field on the stator wire placed under the disk magnet. Instead of a long stator wire with current return via the ionosphere, we return current throughwinding to the next loop of the stator wire. We can wire the entire orbit as a toroidal solenoid, employing the entire magnetic field.

[0096]The new homopolar generatoris shown in Fig. 4. We describe our generator by two analogies, the top drawing of Fig. 4 is based on the analogy of the Faraday homopolar DC generator. The bottom drawing of Fig. 4 is based on the analogy of the Space Tether Experiment. The magnetic rotor is analogous to the rotating earth. The stator coil is analogous to the space tether with current return.

[0097]Faraday's homopolar disk generator has a rotating disk moving at circumferential velocity vat disk perimeter. The perimeter passes through a single magnetic gap of strength B. A radial electric field E = v x B is induced, causing a current to flow from disk center to perimeter

[0098]Current generated is collected by a brush at disk perimeter. Current collected is returned to the center of the disk through an external circuit to power an electrical appliance such as an ohmic heater.

[0099]Our new geometry analogous to Faraday's is shown in the top drawing inFig. 4. We use a cylinder of permanent magnet with north pole on the outside surface of the cylinder and south pole on the inside of the cylinder. The cylinder of the permanent magnet forms the rotor of the generator.

[0100]0ur geometry is different from Faraday's. Our rotor is a circular magnet. Faraday's rotor is a metal disk rotating between magnetic poles. Eddy current flows in the disk around the poles, causing losses.

[0101 ]0ur stator is an outside cylinder concentric with the rotor. The air gap between the stator and the rotor is made small, on the order of a millimeter.An electric field E = v x Bis generated along the length of the stator cylinder, as the radial magnetic field Bmoves at velocity vto induce an upward directed electric field. The two ends of a metal stator cylinder comprise oppositely charged electrodes.

[0102]Voltage is the scalar product of the electric field Ewith the length vectordof the cylinder. If the magnetic rotor cylinder is of depth d = | d | , then the voltage generated is V = E. d = |v| | B |d.

[0103]0perating as a generator, this cylindrical homopolar DC generator creates a current /. Electric power generated \ P_E = IV = I \v\ \ B \ d.

[0104]Electric power is generated by dissipating mechanical power through the magnetic force due to current /. By Ampere's law, the force F due to a current / flowing over a distance d in a magnetic field Bis F = I \ B \ d, ignoring edge effects. This force acts to resist mechanical power produced by the turbine.

[0105]This magnetic force performs work with a mechanical power P_M = F\v \ = / | B |d |v | = IV = P_E, which is changed into electric power P_E . Energy is conserved with exactly the same electric power generated from mechanical power dissipated.

[0106]0ur generator has no dissipative current loop in the cylinder, as the only return path of the current is external to the stator cylinder.

[0107]lnstead of a cylinder with limited voltage V = E. d = |v| | B | d, we may increase voltage by connecting voltage in series. One method of doing so as shown in Fig. 4is to use a stator solenoid of nturns instead of the stator cylinder. The induced voltage in the solenoid is nowV = n || E. d || = n\v\ \ B \d.

[0108]Another configuration of the generator analogous to the Space Tether Experiment is shown at the bottom of Fig. 4. The stator solenoid is placedunder a magnetic rotor cylinder with magnetic axis along the cylinder axis. Another stator solenoid could also be placed above the magnetic rotor. The solenoids could operate as separate voltage sources or be connected in series to double voltage. Inductive force between stator and rotorcan act as magnetic bearing against gravity to levitate the rotor.

[0109]As an example, consider the Hui turbine with radius r = 16cm turning at / = 100Hz. The magnetic field from rare earth magnets is of strength B = 1 T, the height of the magnet is d = 1 cm. The stator winding has n = 100 turns. The electric field strength is | E | = \v x B | = 2nrf x I T = 100.5V/m. The voltage induced is V = n\ E\d = 100.5F. The power of the generator is P = IV in which current / drawn by an external circuit creates a counter torque to the torque force of the turbine.

[0110]Th is Hui generator can also work as the Hui motor. By Ampere's law, the force F due to a current / flowing over a distance d in a magnetic field Bis F = / | B|d, ignoring edge effects. When the rotor is not rotating, there is no electric field E = v x Bfor the zero velocity vector v = 0.

[0111]To operate the Hui generator as the Hui motor, a current controller for / is required to give a force of F = I\ B\d. The current controller fixes current flow regardless of terminal voltage V of the motor. At higher speed, the induced electric field becomes stronger, creating a larger induced voltage V.

[0112]The current controller determines the rate at which electric power P = IV is converted into mechanical power. Modern solid state electronics provides effective current and voltage control to facilitate torque production and speed maintenance.

[0113]The Hui motor has many advantages. Torque and speed control is simple. We can achieve close to 100% efficiency. Induction motors suffer 10+% energy loss from eddy current and magnetic hysteresis. Our motor has no eddy current. We do not use heavy and lossy magnetic cores. Our novel geometry can make motors small. Our DC motorcan use directly DC power sources such as chemical batteries, super- capacitors, solar panels, or our DC generators. We avoid lossy round trip DC to AC conversions.

FIRST APPLICATION OF TAPERING SPIRAL TURBINE: A GAS TURBINE WITH H0M0P0LAR GENERATOR

[0114]0ur heat turbine uses the Brayton thermodynamic cycle to convert heat to work. The pressure versus volume graph of the cycle is shown in the bottom ofFig. 2. The thermodynamic efficiency of the Brayton cycle, comprising the four phases of adiabatic and isentropic compression of airl→ 2, isobaric heat addition and expansion of gas 2→ 3, the adiabatic and isentropic expansion of gas 3→ 4, and the isobaric cooling of the gas post turbine for the purpose of heating 4→ 1.

[0115]Th is Brayton cycle heat engine efficiency is analyzed as follows. Consider the temperature T and pressure p of the gas throughout the Brayton cycle. For adiabatic compression of gas, we have constant pV^r and TV^r~1. The adiabatic coefficient is y = 1.4 for polyatomic gases. Let us assume air and fuel to be at 1 bar pressure and 300K (27°C) temperature. Adiabatic compression of volume by a factor of 8 increases pressure to 18.38 bars and temperature to 689.2/f (343.3°C) .

[0116]When fuel-air mixture is combusted under constant pressure, heat of combustion increases the volume of the combusted mixture, giving out work as volume expands. After isobaric expansion, combusted air expands further as pressure drops towards spiral exit, in reverse of adiabatic compression of fuel-air mix. Work is further given out by the adiabatically expanding gas inside the spiral.

[0117]Work W is the area in the pressure versus volume plot for the Brayton cycle. For adiabatic expansion, pV^r is constant. Pressure P_L and P_H are low and high pressure before and after the compressor. Volume V_L and V_H are low and high pressure volumes before and after the compressor. Work done by the Brayton cycle is

[0118]The constants C, C depend on initial conditions of gas volumes. Renormalizing by the heat of combustion Q for each cycle, the efficiency of this Brayton cycle heat engine is

[0119]Brayton cycle has constant pressure (isobaric) at two steps of the cycle with pressure P_L andP_H. Efficiency depends on the pressure ratio— or the compression ratio—. Carnot heat engine efficiency is given by ε = 1 -, which depends on the low versus high temperature ratio—.

[0120]lf we assume a volume compression of 8 by the compressor, pressure is increased by 18.38 times according to a constant pV^r. Brayton cycle efficiency is

' - ¹ - ^Μ35 - ^α5β5

[0121]An implementation of the Hui heat engine is shown in Fig.5. The bottom is a compressor cylinder which has a constant depth spiral with possibly tapering width. An alternative compressor that may be used is the Archimedes scroll compressor shown in Fig. 9. The top is an expander cone which has a constant width spiral with tapering depth. Compressed air passes from the top center of the compressor to the bottom center of the expander. Fuel flows through a small tube from bottom center of the compressor to ignite in the center combustion chamber of the expander. Pressure force of expanding air post combustion turns the single compressor-expander assembly, providing motive force. Electricity is generated through the homopolar generator at the bottom of the assembly.

SECOND APPLICATION OF TAPERING SPIRAL TURBINE: A DC MOTOR DRIVEN HEAT PUMP/DEHUMIDIFIER

[0122]heat pump and refrigeration uses a refrigerant such as hydrofluorocarbon (HFC). Compressing gaseous HFC pumps heat into the pressurized HFC which liquefies when cooled. Evaporation of liquid HFC under reduced pressure removes heat from the environment. This liquefaction-evaporation cycle constitutes the Rankine cycle heat pump process. However, refrigerants such as HFC if released into the atmosphere are potent global warming gas trapping more than 1000 times the heat for the same volume of carbon dioxide. HFC is scheduled for rapid replacement for developed countries.

[0123]Airplanes use an alternative air conditioning method that uses the Rankine cycle heat pump. Air is bled from the compressor of the jet engine. A mild reduction of air pressure rapidly cools the bled air. I often wonder why chilled air fromcabin air vent is often misty. The mist chills air further with evaporative cooling. I came to the conclusion that the mist comes from the fogging of saturating moisture under increased air pressure. Compressing moist air has the advantage of getting rid of the heat of condensation of air moisture.

[0124]This observation inspired the use of the Hui spiral compressor to produce chilling and water condensate. We explain here the thermodynamic advantages. We introduce here a new thermodynamic heat pump process which we name as the Hui cycleas shown at the bottom of Fig 3. The Hui cycle merges two thermodynamic cycles: the Carnot cycle with isothermal and adiabatic phases and the Brayton cycle with isobaric and adiabatic phases. We replace the adiabatic processes of the Brayton cycle by isothermal processes. Isothermal compression reduces the amount of work needed. Isothermal expansion increases work produced using ambient heat from the environment.

[0125]The Hui cycle requires compressors and expanders with built-in heat exchangers. Heat exchange can be achieved by the ambient air flowing between spiral channels. The phases of the Hui cycle is shown in Fig 3. There are three temperatures: ambient temperature T_a, high temperature T_Hat which heat is extracted, and low temperature r_Lat which chill is produced.

[0126]Phase 1→ 2 is the isothermal compression phase of gas at 7^, requiring compression work W_c = nRT_H In p_H/p_L in which p_H, p_L are the high and low pressures of the isobaric phases. This work is changed entirely into heat of compression Q_c dissipated without increasing the temperature of the gas.

[0127]Phase 2→ 2a is the isobaric cooling of the gas from highr_H to the ambient T_a. Phase 2a→ 3 is the further isobaric cooling of the gas from the ambient T_a to the low T_L.

[0128]Phase 3→ 4 is the isothermal expansion phase of the gas at the low r_L, producing work of expansion W_e by the heat absorbedQ_e, withQ_e = W_e = nRT_L ln p_H/p_L.

[0129]Phase 4→ b is the isobaric heating of the gas from the low T_L to the ambient T_a. Phase b→ 1 is the further isobaric heating of the gas from the ambient T_a to the high T_H.

[0130]We use counter flow heat exchangers to reuse heat. For Phase 2→ 2a, heat given out is exactly absorbed by Phase b→ 1. For Phase 2a→ 3, heat given out is exactly absorbed by Phase 4→ b.

[0131]We attribute performance of heating and chilling as follows. The coefficient of performance of heatingCOPft is the heat produced Q_h divided by the net work done W_net = W_C— W_e. Thus

_{COp =} nRT_H \n p_H/p_L T_H

h ^~ nRT_H In p_H/p_L - nRT_L In p_H/p_L ^~ T_H - T_L

[0132]The coefficient of performance of coolingC0P_c is the chill produced by isothermal expansion Q_e divided by the net work done W_net = W_C— W_e. Thus

_{COp =} nRT_L ln p_H/p_{L =} T_L

c - nRT_H In p_H/p_L - nRT_L In p_H/p_L ^~ T_H - T_L

[0133]Consider the heating of water from T_a = 27°C (300K) to T_H = 77°C (350K) and for cooling of air from T_a " = 27°C ( v300K) ^/ to 7°C ( v280K) ^/. We have C0P_h n = 350³-⁵⁰280 = 5 and C0P_c ^c = 350²-⁸⁰280 = 4.

[0134]l asked why compressing refrigerant such as CFC or HFC, which depletes ozone or traps heat, is preferred over compressing air directly. The Hui cycle can achieve ideal heat pump efficiency. Work is recovered from the expanding gas. In contrast, evaporating refrigerant produces no work. I suppose the preference for liquefaction is that we are better at liquefaction with an effective refrigerant. With effective and compact spiral turbines, we can compress air effectively, avoiding the use of refrigerants.

[0135]Better yet, compressing humid air causes the condensation of moisture in air upon removal of heat of compression. The heat of condensation is dispersed. Traditional air conditioning requires the use of chill produced by the evaporation of refrigerant gas to remove humidity and its heat of condensation. Dehumidifying air increases the work load of the air conditioner for the same drop of air temperature. In urban high rise for which the condenser of air conditioner is located outside the building, condensing humidity often drips down on people, a cause of irritation for pedestrians. We remove this irritation by containing the condensing moisture inside an enclosed condenser. The collected moisture can be emptied by a tube or collected for human and plant consumption.

[0136]Evaporating water exerts a vapor pressure that depends only on temperature. That vapor pressure is part of the pressure exerted by humid air. Each component gas of air such as oxygen (19% by volume), nitrogen (80%), argon (1%), and water (percentage depending on humidity level) exerts its vapor pressure to add up to total atmosphere pressure that is around 1 bar at sea level. [0137]Humidity of air is defined as water content in airdivided by water content in 100% humid air. Dew point is defined as the temperature when that air is cooled to the point that water starts to condense in 100% humid air. Dew point and air temperature are the same with 100% humidity.

[0138]Take for example 100% humid air at 25°C and 14°C, which contains respectively 2 grams of water and 1 gram of water for 100 gram of air. Thus the dew point of 50% humid air at 25°C is 14°C.

[0139]What happens to air moisture if we double the pressure of 100% humid air at 25°C? Initially, vapor pressure of all air components doubles. Humid air, which is heated up by compression, cools back down to 25°C. Since water vapor pressure depends only on temperature, increased water vapor pressure due to compression causes water to condense. Half of the water vapor of air would have to condense out to restore to the same vapor pressure of water at 25°C.

[0140]For high humidity air, a large fraction of the water in air condenses out if we compresses air by a factor of 2 to 3. That condensation releases a significant amount of heat of condensation. Consider increasing pressure by a factor of 2 for 80% humid air at 25°C. That air has 1.6 grams of water per 100 grams of humid air. Pressure would force 0.6 grams of water out. At more than 2200 joules per gram of water evaporated, pressure would drive out 1320 joules of energy for 0.6 grams moisture condensed .

[0141]This heat is significant compared with the latent heat of 100 grams of air cooled by 20°C. Cooling air by 20°Cremoves heatAtf = anRAT = 2.5 x x 8.3 x 20 = 1482/, comparable with the heat of condensation removed. Quadrupling pressure of 80% humid air at 25°C would force out 1.2 grams of water vapor. Water removed from air produces water for human or plant consumption.

[0142]Fig. 6 shows the Hui heat pump for generation of hot water, chilled air, and condensed water. A top compressor at the top compresses air from the bottom center of the compressor into a heat exchanger tube. The tube goes through the center of a water tank, giving its heat of air compression and water condensation to heat up water in the tank. Condensed water and cooled compressed air are collected at the bottom tank. Compressed air drives the expander at the top, giving chilled air for space cooling. Compressed air can also be distributed over nylon tubes to expander in room for chilling as well as generating work and electricity for lighting and consumption by appliances.

THIRD APPLICATION OF TAPERING SPIRAL TURBINE: SOLAR WATER DESALINATION

[0143]We can use the spiral compressor for solar desalination of water. Electricityfor driving the compressor can be produced by solar thermal or photovoltaic power. Solar energy can be collected as heat to boil sea water at reduced air pressure. Our spiral compressor can be used to condense steam from solar evaporated salty water. Compressing low pressure steam raises the temperature for steam to condense. The heat of condensation can evaporate more salty water under reduced pressure.

[0144]Solar desalination was inspired while I was walking around Lhasa in Tibet, China. I heard a loud hissing sound and saw steam coming out of a solar water heater. Water boils at 80°C when atmospheric pressure is halved. Dishes became lukewarm quickly when I dined on a rail car passing through the highest rail pass in the world between Qinghai and Tibet. I asked for microwave reheating of dishes to no avail: my egg foo yung cooled rapidly by evaporation of food moisture in rarefied air.

[0145]We can recreate thislow pressure environment at the head of a tall water column. Water boils at 80°C on top of a 5 meter water column where pressure is halved. A 10 meter water column has zero pressure at the top where water would evaporate profusely. Resulting vapor pressure causes the water column to drop. We would need a pump to remove vapor in order to create a near vacuum at the top. [0146]Fig. 7 shows the Hui solar water desalination device. For conventional solar water heater, solarheat is trapped to heat water in a glass tube that is contained in another vacuumed glass tube. The outer glass tube has a reflective half surface that reflects sunlight onto the inner water heating tube. The Hui solar water heater use a large reflector of light that is shaped like a half cone to concentrate sunlight along a vertically placed tube of water. The reflector tracks the sun in the azimuth positiona, defined as the horizontal angle of the sun from the North for which a = 0. The reflector also tracks the sun in the altitude or elevation, defined as the angle β sunlight makes with the horizon. A directly overhead sun at zenith has β = 90°.

[0147]Fig.8shows a parabolic cone reflector. We call the center line of the parabolic cone the apex line. The apex line should point towards the sun in the horizon, following the azimuth location of the sun. To track the sun in its altitude, the gradient angle δ of the apex line should be such that reflected light shines horizontally on the vertical line of focus where the salty water is heated.

[0148]A horizontal cross section of the cone is a parabola with focus on the vertical z-axis. The vertical location of the focus of that parabolic cross section depends on the elevation of the sun and the inclination of the cone. Consider a directly overhead sun at the zenithwith ? = 90°. If the parabolic cone has inclined at elevation of δ = 45°, overhead sunlight is reflected horizontally onto the column of salty water. The reflector is conic in the sense that the cone is formed by rays from the origin (0,0,0) . The surface of the cone can be formed by hanging a cutout fabric of Mylar on carbon fiber rods that are rays of the cone. The flat Mylar sheet fits on the curvilinear surface of the parabolic cone.

[0149]Consider an elevation of δ = 45° for the cone as shown in Fig. 8. Let the bottom center of the column to be at (x, y, z) = (0,0,0). The parabolic cross section at level z has apex (minimum of the parabola) located at (x, y, z) = (0, -z, z) . Light is focused onto(x, y, z) = (0,0, z) with focal length p = z if the sun is directly overhead with β = 90° as shown in Fig. 8.

[0150]Consider the more general case of/? > 0. The parabolic surface is x² = 4p(y + p) for given vertical level z. We want to reflect sunlight so that it hits the vertical column horizontally. The resulting inclination of the apex line is δ = 90° - , which checks for the cases of the sun at zenith β = 90° when δ = 45°, and the sun on the horizontal with β = 0°when δ = 90°. The apex line is the equation y = z tan δ on the y— z plane. The parabolic cone surface is then x² = 4z tan δ (y + z tan δ) .

[0151]While it is important for the reflector to track the sun well in the azimuth position, it is less important to be able to track the sun in the altitude. The resulting focal line remains on the z-axis, although the line may shift up or down on that axis according to the altitude of the sun. Thus it may be sufficient to have two prearranged inclination δ for the reflector, such as 5 = 60° and δ = 75°. The transition from δ = 60° to δ = 75° can be done by an origami unfolding of the parabolic cone.

[0152]Reduced pressure at the head of water makes water boil at lower temperature. Water boils when vapor pressure of water, which depends only on temperature, is equal to the ambient pressure. As shown in Fig. 7, the key step for water desalination is to compress low pressure water vapor to condense at higher pressure. A spiral compressor is placed above the head of water to remove vapor.

[0153]The compressed and heated water vapor emerges from the center of the spiral compressor into a long thin tube down the center of the water column. Water condenses as water vapor yields its heat in exchange with the surrounding boiling water.

[0154]As water vapor condenses, it yields significant amount of heat of condensation. Capturing this heat of condensation significantly enhances the efficiency of water distillation. [0155]Condensed water is collected in the closed vessel at the bottom of the column as shown in Fig. 7. Fresh water can be pumped out of the condensation chamber which may have reduced pressure.

[0156]At water head, evaporation concentrates saltiness. This heavy and hot brine solution is discharged after yielding its heat to incoming salty water through a counter flow heat exchanger.

[0157]Efficiency of desalination has thermodynamic limits. Heat of evaporation of salty water is more than the heat of condensation of fresh water. Heat is abundantly supplied by the sun.

[0158]lnefficiency results from incomplete heat exchange. Heat is also lost by convection which could be limited by insulation. With good insulation and heat exchange, we expect high desalination efficiency.

[0159]Electricity is supplied by the sun through solar photovoltaic or solar thermal generation. Electricity is used to compress low pressure water vapor. Electric energy is converted into heat of compression. Both heat of compression and condensation are used for more evaporation of salty water.

[0160]We believe this could be a very economical and sustainable way to desalinate seawater for human and plant consumption. Drinking salty water has become a health problem in the Indian subcontinent. Islanders can also draw on solar desalination for drinking and cleaning purposes.

DETAILED DESCRIPTION OF INTEGRATED HEAT TURBINE AND GENERATOR

[0161]Fig. 5 shows the cross section views of heat turbine and generator. The heat turbine comprises a compressor 501 , the heat chamber 502, and the expander 503, with the horizontal cross section view shown as 4-spiral diskson the top and bottom of Fig. 5.

[0162]Four compressor spiral channels 504, 505, 506, 507 turn to compress air from outside in. Compressed air then passes from the center of the compressor 501 into the heat chamber 502. As the compressor turns in one direction (shown clockwise in the figure), gas is compressed by flowing in the opposite direction in the compressor spiral channels (anti-clockwise in the figure).

[0163]For heat generation by gas combustion, combustible gas enters the heat chamber 502 through fuel nozzle 508 where the fuel air mix ignites.

[0164]For heat generation by concentrated solar thermal power, sunlight is focused on the top of the chamber 501 , possibly with a glass top to allow focused sunlight to enter the chamber.

[0165]As a single turbine turning in one direction, the compressor 501 and expander 503 turns in the same direction, shown in the figure as clockwise when viewed top down. Gas expands in the four expander channels 509, 510, 511 , 512. Gas rotates in these channels in opposite direction (anticlockwise) of the rotation of the turbine. Pressure of gas turns the turbine clockwise as shown. Pressure expended gas exits at the periphery of the expander.

[0166]Though gas flows in the same direction (anti-clockwise), the spiral expands in opposite directions for the compressor (clockwise) and the expander (anti-clockwise).

[0167]The expander spirals are tapering by means of decreasing depths, from a larger depth of 513 near the center to a smaller depth 514 near the exit. This tapering allows slow release of pressure in spirals.

[0168]The compressor spirals may be tapered to induce a higher compression ratio. Alternatively, we may employ a stack of multiple compressors in stages. Compressed air from the center of a compression stage is conducted through centrifugal centers to the rim of the compressor in the next stage. We can use a scroll compressor comprising two Archimedes spirals instead of the tapering spiral compressor.

[0169]The turbine spins around two ends 515, 516 on theaxis of spinning fixed on turbine casing. We may use ball bearings, air bearings, or magnetic bearings for smooth spinning.

[0170]The details of the electric generator517 is shown in the bottom ofFig. 4. We place magnets 518 on the rim of the rotor disk with opposite poles on the top and bottom of the disk as shown.

[0171]We use two toroidal solenoids519, 520on top and bottom of the magnets. These two solenoids can be connected in series to double voltage output. These two solenoids can act as magnetic bearing for the turbine.The permanent magnet 518 is levitated by magnetic forces from the solenoids519, 520.

[0172]The two ends 521 , 522form the terminals of the DC generator. An external load 523consumes the electricity generated. A load controller in may be used to control the spin velocity of the turbine. A high voltage increases spin velocity. Low external load resistance increases current flow. High current flow exerts a strong torque resistance to the work provided by the heat turbine.

[0173]The heat turbine may exert work directly on an external mechanical load such as gear box of an automobile or the turboprop of an aircraft. Electricity generated can be stored via chemical batteries or supercapacitors. DC electricity generated is stored without DC to AC inversion. The DC electricity stored can be retrieved as DC to drive an electric motor. The electric motor can be the electric generator of the combined compressor-expander-generator-motor shown in Fig. 5. We may not need another motor.

DETAILED DESCRIPTION OF AIR CONDITIONER AND DEHUMIDIFIER

[0174]An implementation of an air conditioner and dehumidifier is shown in Fig. 6.

[0175]One implementation using the same structure of a single combined turbine of compressor 601 and expander 602. No heat chamber for heat absorption is needed. Heat may be sufficiently dispersed by forced air flow in between spiral channel. Compressed and partly cooled air may enter directly into the expander602 for further cooling. The expander acts also as a fan to blow cool air directly on human body for effective personal cooling.

[0176]lnstead of routing partially cooled compressed air directly from the compressor to the expander, we may divert compressed air downward to heat exchanger 603 that yields gas heat to a water heating tank 604. Cooling of compressed air yields its moisture condensing in chamber 605 and collected through 618. Cold water enters at 616 to be heated in the water tank 604. Hot water is extracted at 617.

[0177]Cool compressed air is then further cooled by ambient air through a conduit 606 to the expander 602. Pressure expended air from the expander 602 is ducted through vent 607. The expander also serves as an air blower for delivery of cooled and dried air to rooms in a building.

[0178]The compressor is powered by the DC motor 608identical in structure to the DC generator for the heat turbine. The rotor magnet 609is a ring with magnetic axis aligned with the rotor axis of rotation. The stator coils610, 611are powered by DC power source 612.

[0179]A motor control 613controls motor voltage and current. Voltage controls spinning velocity. The compressor motor is ramped up gradually to the required speed for compression. Current controls torque force required for the compression. The compressor is hinged with bearing at 614, 615. [0180]An alternative implementation decouples the compressor 601 from the expander. Compressed air could be delivered by thin nylon tubes to individual rooms. An expander is located in each room, delivering chill and possibly electricity generated by the spinning expander.

[0181]This alternative could be used for villages with centralized compressor and electricity generator. Power for the compressor could be derived from solar panels or from our heat turbine driven by solar heat or gas combustion. We deliver compressed air to huts instead of power through metallic conductors. Compressed air provides chill as well as low voltage DC for LED lighting, TV, and battery charging. Compressed air could also be stored in large volume for evening usage.

DETAILED DESCRIPTION OF SOLAR WATER DESALINATION

[0182]Fig. 7 shows a water desalination system that employs solar power to evaporate salty water under reduced pressure. Power source714 for driving the compressor 704 may use solar energy.

[0183]The system configuration of the water heating and steam condensation subsystem is very similar to that for air conditioning with dehumidifying. We compress low pressure steam instead of humid air.

[0184]A tall water column 701 has reduced pressure at head water 702. The salt water tank 703 may be made of strong glass, reinforced concrete, or ceramic material that can withstand salt water corrosion.

[0185]Above the head of water and inside the water tank 703, a compressor 704 driven by a motor 705 draws in low pressure steam from inlets 715. Compressed steam then condenses after exiting the compressor hinged at 712, 713. Condensing water heats salty water in tank 703 for further evaporation.

[0186]The circulation of salty water is as follows. Salty water can be preheated before entering water chamber 703 through inlet 710. Preheating can be achieved through heat exchange with salty brine waste. We may preheat salty water in solar water heaters with vacuumed glass heating tubes.

[0187]A parabolic solar power collector 709 focuses solar energy onto the salty water column 703. A more accurate geometry of the collector is shown in Fig. 8. Focused sunlight heats up the salty water, which rises to the top 716 and evaporates profusely with the reduced pressure at heat of water. The water is also heated by the condensing steam in the heat exchanger 706.

[0188]Denser brine migrates to 717, cools because of further evaporation, and sinks to the bottom. The brine waste exits at 711. Heat exchange may occur between hot brine waste and incoming salty water.

[0189]To facilitate circulation from inlet 710 to outlet 711 through the top locations 716, 717, we may partition the vertical volume of the salt water tank into sectors. The sector boundaries can also absorb focused sunlight should the salty water tank be made of transparent glass.

[0190]Water condenses in the chamber 707, which can be drawn out through 708.

[0191]Solar power can also be provided by concentrated solar driven heat turbine. Hot air exhaust from turbine can be used to heat the water column instead of concentrating mirror 709. Combined heat engine and solar water desalination can be a true life saver for ocean vessels and stranded islanders. CONCLUDING REMARKS

[0185]There are three essential elements for human survival: air, water, and sunshine. From these three, perhaps with the assistance of gaseous fuel as backup, we derive all human comforts of cooling, heating, food, water for drinking and cleaning, and energy needed for communications, computing, and transportation. We believe the inventions described will provide these human comforts where and when needed through the paradigm of personal energy instead of centralized generation.

[0190]Acknowledgment: Jim Hussey, Ankur Ghosh, Forest Blair, and Jerry Jin of Monarch Power implemented and tested early versions of turbine. Professors Daniel Bliss of Arizona State University,YC Chiew of Rutgers University, and Falin Chen of National Taiwan University stimulated discussion of the fluid dynamics of the spiral turbine. Professor Keng Hsu of ASU3D laser printed a metal turbine model.

Claims

I claim for the tapering spiral turbine:

[1 ]An expander for pressurized gas to convert pressure energy into motion, said expander comprising: a plurality ofcoaxial disks each with a plurality of enclosed spiral channels for spiral flow of gas from the center to the perimeter of each disk; each of said spiral channels comprising:

increasing radii comprising an angle that increases linearly or exponentially as the angle turned by gas in said channel, and a bore area that decreases as the angle turned by the spiral channel;

to provide gas flows with pressure that decreases gradually with angle turned by exerting pressure force on the outer spiral channel wall so as to produce a larger torque force than the inner spiral channel wall with a smaller wall area and radius.

[2]A compressor using motion to compress a gas and increase gas pressure, said compressor comprising: a plurality of coaxial disks each of said plurality of coaxial disks comprising a plurality of enclosed spiral channels for spiral flow of gas from perimeter of each disk to the center of the disk; each spiral channel comprising:

decreasing radii that decreases linearly or logarithmically as the angle turned by gas in channel, and a bore area that may increase as the angle turned by the spiral channel;

wherein gas flows with pressure that increases with angle turned by the outer spiral channel wall pressing against the gas with a larger torque force than the inner spiral channel wall with a smaller wall area and radius.

[3]A compressor-expander combination of compressor of Claim 2 and expander of Claim 1 , said combination of compressor comprising:

coaxial stacking ofa plurality of compressor disks arranged in stages with the compressed gas from the center of a disk being directed to the perimeter input of a disk in the next stage so that gas pressure increases from a first stage to said next stage;

a plurality of expander disks arranged in stages with partially expanded gas from the perimeter of a disk being directed to the center input of a disk in the next stage so that gas expends its pressure for work; a conduit of pressurized gas from the compressor stack to the expander stack being an opening between conjoined compressor and expander wherein the conduit is external and further comprises pressurized gas storage between compressor and expander.

I claim for the homopolar DC generator:

[4] An electricity generator for converting motion into electricity, said generator comprising a rotor disk coaxial with a stator disk on one or two sides of the flat surface of the rotor disk, further comprising: a rotor disk is anannulus of permanent magnet with polarity oriented axially in the vertical direction; a stator disk is a coaxial toroidal solenoidwith two ends of the solenoid wire comprising the positive and negative electrodes interconnected with other electrodes; with

wherein the generator produces electricity according to the right hand rule for induction of electric field in the radial direction by motion of the rotating and vertically oriented magnetic field of the rotor, producing electric power as a product of the voltage and current induced. [5] An electric motor converting electricity into motion, said motor comprising a rotor disk coaxial with a stator disk on one or two sides of the flat surface of the rotor disk, for which:

a rotor disk is an annulus of permanent magnet with polarity oriented axially in the vertical direction; a stator disk is a coaxial toroidal solenoid with two ends of the solenoid wire comprising the positive and negative electrodes interconnected with other electrodes;

wherein the motor produces rotating motion according to the right hand rule for the Lorentz force with vertically directed magnetic field of the permanent magnet interacting with the magnetic field generated with the radially directed electric current in the stator disks to produce the Lorentz magnetic force acting in the circumferential direction of the rotor magnets.

[6]Theelectricity generator of Claim 4 and an electric motor of Claim 5for which the electricity generator of Claim 4 operates some of the time putting electricity to be stored in another electric power storage device to be retrieved later for driving the same electricity generator of Claim 4 operating as an electric motor of Claim 5.

I claim for the heat engine:

[7]A disk shapedturbine powered by a pressurized gas, comprising:

a central chamber into which the pressurized gas is injected by male nozzles and the gas is heatedin the chamber by means of fuel combustion or concentrated solar energy;

a plurality ofspiral channels radiating from said central chamber, said plurality of spirals comprising expanding radii and tapering bore;

the tapering bore adaptedto release pressure gradually through the length of the spiral and out of a perimeter of said turbine;

whereinsaid turbine is adapted to retain pressure to act on the perimeter, the perimeter having a larger outer surface area than an inner surface area of the tapering bore, thus allowing the gas pressure to rotate said turbine in the opposite direction of the gas flow.

[8]The disk shaped turbine of claim 7, further comprising a combined turbine and generator, whereinsaid disk turbine is mated with an electric generator and adapted to serve as a rotor for said generator, further comprising an annulus of electromagnets around said disk turbine adapted to induce direct current electricity on stator coils that are co-axial with the disk shaped turbine of claim 7.

[9]The disk shaped turbine of Claim 8 further comprising a heat engine and a generator wherein said disk turbine is mated with an electric generator and adapted to serve as a rotor for said generator, further comprising an annulus of electromagnets around said disk turbine adapted to induce direct current electricity on stator coils located at the periphery of a turbine casing, and further comprising a disk shaped compressor made to rotate by an external torque, comprising:

a central chamber adapted to allow compressed gas to exit

a plurality of spiral compressor channels radiating from said central chamber, said plurality of compressor spirals comprising expanding radii and tapering bore;

wherein gas compressed from the outside of said compressor is forced to the inside of through said spiral channels in reaction to compressing force of the larger outer surface area of these compressor spiral channels; wherein said turbine is adapted to drive said compressor via torque force pressure.

[10] The disk shaped turbine of Claim 9 wherein said disk shaped turbine and said disk shaped compressor comprise a conic shape with a linear tapering of each of said plurality of spirals and said plurality of compressor spirals, said linear tapering comprising a linear relationship between channel depth versus spiral radius.

[11] Thedisk shaped turbine of Claim 8 wherein said disk shaped turbine comprises an Archimedes scroll compressor driven by an electric motor.

[12] The disk shaped turbine of Claim 7 wherein said plurality of spiral channels have radii that grow exponentially as the angle turned.

[13] The disk shaped turbine of Claim 7 wherein said plurality of spiral channels have a bore size that decreases exponentially as the angle turned.

I claim for the heat pump:

[14] A method of utilizing compressed gas to drive a turbine said method comprising the steps of:

forcing gas through a compressor into a spinning turbine central chamber, whereby the spinning turbine chamber comprises:

plurality of enclosed channels for spiral flow of gas from the center to the perimeter of each disk; and with each spiral channel comprising:

increasing radii that increase linearly or exponentially as the angle turned by gas in channel and bore area that may decrease as the angle turned by the spiral channel;

such that gas flows with pressure that decreases gradually with angle turned by exerting pressure force on the outer spiral channel wall that produces a larger torque force than the inner spiral channel wall with a smaller wall area and radius.

[15] The method of Claim 14, further comprising the step of producing chill via a compressor via expanding compressed air in a spiral of the spinning turbine;

said step of producing chill completed without injection of heat by combustion or concentrated solar energy.

[16] The method of Claim 14, wherein the compressed gas is delivered by tubes from a disk shaped compressor made to rotate by an external torque, comprising:

a central chamber adapted to allow compressed gas to exit

a plurality of spiral channels radiating from said central chamber, said plurality of spirals comprising expanding radii and tapering bore;

wherein gas compressed from the outside of said compressor is forced to the inside of through said spiral channels in reaction to compressing force of the larger outer surface area of these spiral channels.

[17] The disk shaped compressor of Claim 16, further comprising a motor adapted to utilize said disk compressor as a magnetic rotor of an electric motor adapted to drive said compressor, with direct current flowing in a plurality of solenoid, driving a rotor magnet with axial magnetic rotor. [18] The disk shaped compressor of Claim 16further comprising heated liquid, said liquid heated via heat of compression of air.

[19] The disk shaped compressor of Claim 16 further comprising potable water, said potable water being derived via said gas wherein sad gas comprises humid air, and said potable water is extracted from moisture in said humid air after compression.

[20] The disk shaped compressor of Claim 16 further comprising a container adapted to receive air from said compressor, said container adapted to store air after dehumidified as cooled, pressurized and dehumidified air, and further comprising a disk shaped turbine powered by a pressurized air supplied from said container, said disk shaped turbine comprising:

a central chamber into which the pressurized gas is injected by male nozzles and the gas is heated in the chamber by means of fuel combustion or concentrated solar energy;

a plurality of spiral channels radiating from said central chamber, said plurality of spirals comprising expanding radii and tapering bore;

the tapering bore adapted to release pressure gradually through the length of the spiral and out of a perimeter of said turbine;

wherein said turbine is adapted to retain pressure to act on the perimeter, the perimeter having a larger outer surface area than an inner surface area of the tapering bore, thus allowing the gas pressure to rotate said turbine in the opposite direction of the gas flow.

[21] The disk shaped compressor of Claim 16 wherein said plurality of spiral channels have radii that grow exponentially as the angle turned.

[22] The disk shaped compressor of Claim 16 wherein said plurality of spiral channels have a bore size that decreases exponentially as the angle turned.

[24] The disk shaped compressor of Claim 16 wherein said plurality of spirals have constant width but spiral channel depth decreases exponentially as the angle turned.

I claim for solar water desalination:

[25]A solar water purification device comprising:

a reflective parabolic conic surface to concentrate solar power, with a central apex line that tracks the azimuthal position of the sun;

a vertical column at focal line of reflective parabolic conic surface containing water to be purified;

a compressor inside the vertical column for compressing low pressure steam at head of water column; a heat exchanging tube using heat of condensation of compressed steam by to water column; and a condenser chamber to collect condensed steam as potable water.

[26]The reflective parabolic conic surface of Claim 25 with increased altitude of the central apex line to track the altitude position of the sun above the horizon.

[27]The solar water purification device of Claim 25 wherein the compressor comprising a plurality of disk compressors each with a plurality of spiral gas channels of decreasing radii and increasing channel bore area such that a gas is compressed by the outside channels of the spiral that turns in a direction to push gas towards the center of the disk compressor, raising the pressure and temperature of the gas.

[28]The solar water purification device of Claim 25 wherein the compressor is powered by a disk motor with magnetic rotors with axial magnetization and solenoid stators driven by direct current electric to produce the rotary motion for gas compression.

[29]The solar water purification device of Claim 25 wherein the vertical column is adapted to be used to produce reduced water pressure at head of water column for lowered temperature of evaporation, such that the low temperature and pressure steam generated may be compressed to yield water and heat of condensation for further evaporation of water to be purified.