GB1573783A - Rotary thermodynamic system and method - Google Patents

Description

(54) ROTARY THERMODYNAMIC SYSTEM AND METHOD (71) I,FREDERICK WILLIAM KANTOR, a citizen of United States of America, of 523 West 112th Street, New York, N.Y. 10025, United States of America, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to rotary thermodynamic systems and, more particularly, stabilizing the operation of such systems, which may, for example, include rotary heat pumps or refrigeration devices as shown in U.S. patent 2,393,338, or heat pumps and compressors as shown in U.S. patents 3,470,704, 3,456,454 and 3,559,419.

It has been found that in some of the prior systems and devices of the type described in the foregoing patents, instabilities in the fluid flow can occur. Such instabilities can take the form of run-away or uncontrollable fluid flow, in which the total pressure drop in the rotary fluid flow conduit decreases with increase of the rate of fluid flow through the conduit. This renders the device inoperative. Another form of instability occurs in devices having rotary fluid flow conduits connected in parallel. In such devices, the fluid flow can divide unevenly among the various parallel branches, and the flow even can reverse its direction in some of the branches. The run-away type of instability described above also can occur in such parallel-branch devices.

It is an object of the present invention to produce a rotary thermodynamic system and method which is free from such instabilities, which operates with a satisfactorily high efficiency, has small size and weight, and which is capable of operating reliably under a wide variety of environmental conditions.

The present invention consists in a rotary thermodynamic system comprising a rotary thermodynamic device including at least one fluid flow conduit having radially outwardly-directed and inwardly-directed sections in which conduit the thermodynamic pressure drop decreases with an increase in the rate of flow of working fluid through said system, and mechanical and/or thermodynamic impedance control means for providing an increase of pressure drop for an increase in the rate of flow of working fluid through said conduit, the amount of said increase in pressure drop being effective to cause the overall pressure drop for said system to increase with an increase in said rate of flow, thereby stabilizing the flow of working fluid through said conduit.

The invention also consists in a method of stabilizing the operation of a rotary thermodynamic system comprising a rotary thermodynamic device including at least one fluid flow conduit having radially outwardly-directed and inwardly-directed sections, there being a decrease in the pressure drop in said conduit with an increase in the rate of flow of working fluid through said conduit, said method comprising controlling the mechanical and/or thermodynamic impedance in said system so that there is an increase in pressure drop for an increase of the flow rate of working fluid through said system, said increase being greater than said decrease so as to give said system an overall pressure drop which increases with increases in said flow rate.

In the accompanying drawings: Figure 1 is a schematic drawing of a general analytical model of systems and devices to which the invention is applicable.

Figures 2 to 17 schematically illustrate different embodiments of the invention.

In each figure of the drawings, the axis of rotation is given the reference numeral 1, unless it is specified otherwise.

Definitions of Terms The following are definitions of terms used in the description of the invention: A Rotary Inertial Thermodynamic System (RITS) is a system using at least one Rotary Inertial Thermodynamic Device (RITD), together with internal and/or external thermodynamic and/or mechanical impedances to heat and fluid flow for the device.

A Rotary Inertial Thermodynamic Method (RITM) is a method utilizing at least one RITS.

A Rotary Inertial Thermodynamic Device (RITD) is a device at least part of which rotates to develop inertial forces (centrifugal and Coriolis forces) in a working fluid or fluids flowing in the device, which forces give rise to variations in the density, temperature, pressure, and/or flow of the working fluid(s).

Thermodynamic Impedance is the impedance to the flow of heat or fluids caused by thermodynamic conditions. The thermodynamic impedance of a heat flow is measured by the temperature drop per unit of heat flow. The thermodynamic impedance of a fluid flow is measured by the pressure drop, caused by the thermodynamic conditions, per unit of fluid flow.

Mechanical Impedance is the physical impedance to fluid flow. Mechanical impedance is measured in units of pressure drop per unit of fluid flow. The mechanical impedance of a device is positive if the device retards flow through it, and is negative if it promotes or allows the free flow of fluid through it. Mechanical impedances- are caused, for example, by friction between the fluid and the conduit in which it is flowing, turbulence or valves.

The Impedance About An Operating Point, for both thermodynamic and mechanical impedances, for small fluctuations in the flow rate about an operating point, is the derivative with respect to fluid flow rate of the temperature or pressure drop associated with the fluid or heat flow. This derivative corresponds to the slope of the line tangent to the graph of pressure or temperature drop versus flow rate at the operating point.

Stability of Flow:-Flow of a working fluid at selected operating conditions is said to be stable if changes in flow lead to effects, such as changes in driving or retarding pressures, which tend to restore the flow to its original value, and unstable if resulting effects tend to cause further departure from the original value.

Examples of rotary inertial thermodynamic devices, systems and methods are given in the above-identified U.S. patents.

General Principles of the Invention Figure 1 shows a general analytical model of a rotary inertial thermodynamic system (RITS) with which this invention is concerned. The system includes a rotary inertial thermodynamic device (RITD) having internal mechanical impedances ZMINT, and internal thermodynamic impedances designated ZTINT. At least one device in the system is rotated with an angular velocity W. The system has external mechanical impedances ZMEXT and external thermodynamic impedances ZTEXT. The performance of the system can be affected by any or all of these impedances.

As a general principle, it has been found that the stability of a RITS can be maintained if the total mechanical and thermodynamic impedance is positive; that is, if the total pressure drop in the system increases with an increasing fluid flow rate.

Several examples now will be given to illustrate how the invention is applied to specific systems and devices.

Elementary Heat Pump Figure 2 shows schematically two forms of an elementary heat pump embodying the - present invention. This heat pump can be used for heating or cooling, as desired.

The heat pump includes a "U"shaped fluid flow conduit or tube 11 which is rotated about an axis 1 in the direction of the arrow 12. This tube 11 has an inlet 2, a radially outwardly directed or outgoing section 3, a paraxial section 15, and a radially inwardly directed or ingoing section 4 with an outlet 5. Compressed gas is introduced into the tube 11 at the inlet 2, and proceeds through the section 3, which contains a heat exchanger 29 to help conduct away some of the heat of compression of the gas as it is compressed in setion 3. The gas then flows through the paraxial section 15, in the direction of the arrow 31, with negligible temperature or pressure change. Next, the gas flows radially inwardly through conduit section 4 which contains another heat exchanger 30 which helps conduct heat from the environment into the gas. This is the location at which useful cooling is done, if the heat pump is to be used for cooling purposes. If desired, the heat exchanger 30 can be omitted and cooling can be reduced or eliminated from section 4, so that cooling can be done elsewhere by the gas issuing from the outlet 5.

Shown schematically in Figure 2 is an embodiment of the invention which includes a return conduit carrying gas from the outlet 5 of the tube 11 to the inlet of a compressor 28 which then compresses the gas and pumps it through the heat pump again. Preferably, the return conduit and compressor are stationary, and rotary seals connect the rotating tube 11 with the compressor outlet and the return conduit.

In some prior art devices of a type similar to that shown in Figure 2, stability is not certain. However, in the device shown in Figure 2, the flow is stabilized by one or both of two different means. One such means includes the heat exchangers 29 and 30 which preferably are of the type having a plurality of thin, elongated gas flow passageways. Such heat exchangers add a considerable amount of mechanical impedance to the flow of working fluid through the heat pump. If this mechanical impedance is made large enough, the total pressure drop through the system will increase with increasing fluid flow rate regardless of the type of external compressor 28 which is used.

Another means of stabilization is to make the compressor 28 of a positivedisplacement type, e.g. a piston or slidingvane type of pump. Such a pump will not permit run-away or uncontrolled flow, and thus will stabilize the flow.

The magnitudes of thermodynamic and mechanical pressure drops at a given flow rate in the device shown in Figure 2 depend on the ability of the heat exchangers 29 and 30 to conduct heat between the working fluid and the environment. This ability depends upon the impedance of the structure or heat exchanging fluid in the exchangers 29 and 30. Thus, the total heat flow impedance depends upon both internal and external impedances. As a result, the thermodynamic pressure drop and the flow of working fluid depend on both external and internal heat transfer properties. This makes it necessary to analyze the entire system to understand the behavior of the working fluid flow.

Shown in dashed outline in Figure 2 is another fluid flow branch 33 which is substantially identical to branch 32 described above. Branches 32 and 33 are connected in parallel with one another so that the fluid flow divides between them.

Preferably, the branches are substantially identical to one another and are located symmetrically with respect to one another so that they provide a balanced rotational structure. If the mechanical impedances provided by heat exchangers 29 and 30 in each parallel branch is sufficiently high, the flow will divide between the branches properly and the device will be stable.

However, the sole use of mechanical impedances for stability control is not preferred since the mechanical impedances introduce irreversible losses which reduce the efficiency of the device.

Elementary Compressor Figure 3 shows an elementary rotary inertial thermodynamic compressor (RITC) for converting heat energy into mechanical flow energy, i.e. for pumping and/or compressing a fluid. The compressor again includes a "U"-shaped conduit or tube 52.

Gas flows in through an inlet 53, and then radially outwardly in a section 50 in which the gas is compressed adiabatically to a higher pressure and temperature by centrifugal force. The gas then flows through a section 48 which is parallel to the rotary axis 1 about which the device is rotated. Gas flows in the direction indicated by arrow 54 into an inwardly-directed section 62 containing a heat exchanger 46. Heat is applied to the gas in section 62 through the heat exchanger, as is indicated by the arrow 61. This allows isothermal expansion of the gas in the heat exchanger. The gas then further expands adiabatically in portion 51 of section 62. The gas emerging at exit 49 has a higher pressure and temperature than it had at the inlet 53.

The reason for the compression of the gas is that, on the average, gas is denser in the section 50 of the conduit than it is in the section 62. Centrifugal forces act on this density difference, thus producing a net forward pressure.

An increase in the flow rate reduces the 'effectiveness of the heat exchangers and leads to smaller temperature and density differences, and to a smaller net forward pressure. However, this effect depends upon the heat source impedance; that is the impedance opposing the flow of heat from the heat source into the working fluid.

If some external force or object were to momentarily reverse the flow of gas through the RITC of Figure 3, region 51 would fill with cooler gas, and section 50 would fill with heated gas, causing a reversal of the direction of pumping. Thus, operation of the device is unstable near zero flow, since small fluctuations might then reverse the flow. Therefore, the load on such a compressor should not have too high an impedance relative to the characteristics of the system, and the operating point of the compressor with its load should be chosen so that the flow is substantially different from zero.

Several compressors can be connected in parallel in a manner similar to that discussed in the description of Figure 2. In such a parallel conduit compressor the operating point should be different from zero by a larger amount than with a single-branch device because the least effective compressor branch can suffer flow reversal at a slightly lower pressure than the others, and can effectively short-circuit the compressor.

Heat Sources One way in which to ensure a high overall system impedance and thus enhance stability is to use a high-impedance heat source. Examples of such heat sources include flames, hot gases, electricallyheated heating elements such as resistors, electron beams, radiant electro-magnetic energy such as light, an induction-heated dielectric element within the rotating device, a dielectric heating source, nuclear reactions, and the decay of radioisotopes.

Cascaded Compressor Pumping action by the compressor of Figure 3 depends upon the action of centrifugal forces on the net difference in density between the gas in the inwardly and outwardly-extending conduit portions 62 and 65. If the gas has a fixed temperature, the density difference (for an ideal gas) is proportional to the pressure of the gas.

Thus, for flow rates low enough to allow effective heat exchange, the pumping pressure difference produced by the compressor is approximately proportional to the inlet pressure. Applicant has used this fact to advantage in providing a cascaded compressor as shown in Figure 4.

The cascaded compressor 199 shown in Figure 4 includes three compressor loops 202, 203 and 204 connected in series with one another. Each loop is virtually identical to the single-loop compressor shown in Figure 3. The only difference is that additional heat exchangers 135 and 139 are located at the innermost end of the outgoing conduit sections 136 and 140 in loops 203 and 204. These heat exchangers conduct away the heat of compression of the gas in sections 136 and 140.

The outlet pressure of each stage of the compressor 199 is its inlet pressure multiplied by the compression ratio for that stage. The total outlet pressure of the cascaded compressor is, therefore, the product of the compression ratios of the individual stages; that is, the output pressure of the compressor increases exponentially with the number of stages.

This is a highly advantageous feature in that it permits the production of very high compression ratios, or permits the size, speed, or input temperature of the device to be reduced without reducing the outlet pressure below that needed. Such a cascaded compressor can deliver gas into a load having substantially higher impedances than can a single-stage compressor under similar circumstances.

Further advantages can be obtained by connecting compressor stages or series of stages in parallel with one another. Flow reversal in any of the parallel branches can be prevented either by designing each branch so that it will not reverse the flow when delivering gas into a load having an impedance slightly greater than the maximum output pressure of the branch, or by placing a check valve in each branch.

The series combination of one or more stages having low mechanical impedance and high thermodynamic impedance with one or more stages having low thermodynamic impedance provides good performance over a wide range of fluid flow rates. The stages having high thermodynamic impedance contribute a substantial compression affect at low fluid flow rates, thus protecting against flow reversal, while at high flow rates, the performance is substantially that of the compressor having low thermodynamic impedance.

Helical-Toroidal Thermodynamic Compressor Figures 5 arid 6 show a cascaded multistage thermodynamic compressor 500 with stages like those shown in Figure 4, but arranged in a particularly advantageous formation.

As is shown schematically in Figure 5, the compressor 500 includes two groups of loops 510 and 512 of tubing. Each group of loops is formed by winding a single length of tubing in a pattern tending to form a toroid.

Each loop 510 is opposite to a loop 512 in the opposite group, and the loops are arranged symmetrically with respect to the central axis 517 of the toroid.

The starting end of the upper group of loops 510 is connected to the starting end of the opposite group 512. This connection is indicated by reference numeral 516.

Similarly, the trailing ends of the groups are connected together as indicated at 518. Thus, the two groups are connected together in parallel. A refrigeration unit or other load 519 is connected to the conduits 516 and 518. The refrigeration unit 519 contains, for example, means of the type described above for centrifugally compressing, expanding and returning a working fluid to the compressor 500 through the conduit 516. The compressor 500 and the refrigeration unit 519 are connected together to be rotated as a rotary heat pump unit by a motor 504.

As is shown in Figure 6, the loops 510 and 512 are secured between a pair of heatconducting metal plates 506 and 508 by means of welding or soldering. The plates 506 and 508 are secured to a hollow shaft 502 through the center of which pass tubes 516 and 518. Insulation 514 fills the toroidal hole formed by the loops 510 and 512. The plates 506 and 508 may have suitable heat transfer fins on their outer surfaces.

Heat is conducted into plate 506 from a suitable heat source, and is dissipated from plate 508 into the environment. The various compression stages are arranged so that all of the heat exchangers 135, 139, etc., through which heat is rejected, contact the plate 508. Similarly, heat exchange means 133, 137 and 141, through which heat is absorbed into the working fluid during expansion, make thermal contact with the plate 506 through which heat flows into the working fluid.

The compressor 500 operates as follows: Heat is added to the portions of the loops in which the working fluid flows towards the axis 517 by heating the plate 506, and the portions of the loops in which the fluid flows away from the axis 517 are cooled by cooling the plate 508. Rotation of the loops augments the pressure difference between the outwardly and inwardly-flowing fluid columns in each loop in the manner discussed above. Since the loops in each group are connected together in series, the compression produced by each loop multiplies that produced by the preceding loops in the group, with the result that relatively high total fluid pressures can be produced with working fluids of relatively low density, or with the use of relatively low rotational speeds, or with rotary devices having relatively small- diameters.

Alternatively, rather than using this embodiment of the invention to reduce the foregoing parameters, it can be used simply to produce very high total fluid pressures.

The arrangement of the loops into two parallel-connected groups is made in order to ensure that opposite portions of the rotary structure will have the same amounts of fluid in them at the same time and the rotational balance of the structure will be maintained. Additional parallel-connected groups can be added as desired.

Impedance-Induced Compression In Figure 7 is shown a RITC 549 whose operation depends entirely upon heat flow impedance effects, and which will pump gas in either direction. Heat is applied from a source 557 to the gas in both the outgoing and ingoing conduit sections 552 and 555, with the conduit spinning about the axis 1.

Heat-exchanger 554 has a low thermodynamic impedance, whereas the impedance to regions 552 and 555 is relatively high. The compressor 549 operates if there is a rate of flow of gas great enough to render stray heating in region 552 or 553 negligible compared to that in heat exchange means 554. Then, the region downstream from heat exchange means 554 will contain gas at lower density than the region upstream thereof, and net pumping occurs.

Gaseous-Liquid Thermodynamic Devices To be stable when gas is supplied from a gas source having a low mechanical impedance to flow, a RITD should have a net positive impedance to flow at and near a chosen operating point. In Figure 8 is shown a RIT cooler which has an automatically self-adjusting back-pressure, one which increases with increasing flow. Vapor enters under suitable pressure through inlet 580 in the direction of arrow 579, to condense in chamber 582, rejecting at least some heat of condensation through thermodynamic impedance Z44. Chamber 591 is maintained at a lower pressure than chamber 582 by the flow of vapor through an outlet 590 of the chamber 591. The pressure difference between the chambers 591 and 582 is counterbalanced by centrifugal forces acting on the radial head R of liquid between surfaces 592 and 593 in the chambers 582 and 591, respectively.

Liquid 586 absorbs heat through an impedance Z46 and evaporates at the reduced pressure in chamber 591, producing the desired cooling. If desired, the cooled vapor may itself be used in subsequent processes.

If there is a faster intake of vapor, the heat of condensation must be rejected faster, with a larger temperature drop across impedance Z44. This produces a higher temperature and pressure in chamber 582.

Supposing that the outlet pressure remains relatively unchanged, the increased pressure difference between the two chambers 582 and 591 can displace the liquid surface 592 further radially outwardly relative to surface 593. Such displacements of liquid surfaces leads to more contribution from centrifugal force in creating backpressure, and a new stable operating point is reached. This self-adjustment can continue until finally a pressure difference is developed which is large enough to force vapor past the liquid in chamber 591. The pressure difference at which this occurs can be very large.

The opposing columns of liquid in the device 594, including the interconnecting liquid trap 585, can be considered as comprising a self-adjusting mechanical impedance Z45, which provides stable operation for this device. Thus this cooler is stable with any gas source having a positive impedance. Similarly, multiple coolers of this type can be stable when connected in parallel.

The device 594 also can be used as a compressor. When the device 594 is so used, heat is added to chamber 591 from a suitable heat source through thermodynamic impedance 246, raising the temperature and pressure of the gas in chamber 591 to values greater than those in 582. Liquid surface 592 backs up into chamber 582, for example, to a radial distance R1 from surface 583 of chamber 582, and now lies closer to the axis of rotation 1 than does the liquid surface 593.

Centrifugal forces on the opposing liquid columns tend to drive the liquid into chamber 591 to counterbalance the higher pressure therein. As the pressure difference between the gases in chambers 582 and 591 increases, so does the liquid head counterbalancing it, until the liquid level 593 in chamber 591 moves out to the surface 587 of chamber 591. This substantially curtails heat flow into the liquid and reduces the rate of evolution of vapor, thus allowing the pressure in chamber 591 to decrease.

Thus, the self-adjusting impedance Z45 resulting from the construction of this device is operative to stabilize the operation of the device 594 for both forward and backward pressure differences.

With suitable design, heating of the liquid in the trap 585 can be made negligible. This ensures that the device 594, when acting as a compressor, will not produce enough pressure to reverse flow through itself. That is, additional pressure beyond that which is produced in the device 594 would be necessary to force the liquid surface 593 radially outwardly to the bottom of the trap and reverse the flow. Thus, the compressor is suitable for use in parallel with other compressors.

Figure 9 shows an absorptive rotary compressor, another device whose operation is stabilized by a self-adjusting impedance. Gas entering at 672 in direction 670 is absorbed in chamber 673 by liquid 687, giving up heat of absorption through thermodynamic impedance Z693, if necessary. The resulting solution or "liquor" 674 proceeds in the direction 675 through a conduit 676 to a portion 691, and then radially inwardly to a heating chamber 681, wherein heat is added through an impedance Z677 from a heat source 678. This causes evolution of the gas from the liquor 680.

Alternating small portions of gas and liquid bubble inwardly through a conduit 683 in the manner described in my U.S. Patent No.

3,559,419.

The average density of the fluid column in conduit 683 is less than that of the liquor 674 in duct 676. Centrifugal effects acting on this density difference encourage flow in the direction of arrow 682, through outlet 684 into a chamber 685 in which the gas and liquid substantially separate. Additional heat can be added to liquor 852 in chamber 685 from a heat source 854 through impedance Z851 to promote further gas evolution. Compressed gas leaves the compressor in the direction of arrow 671.

Liquor spills over an optional dam 850 to enter a conduit formed to act as a rotary inertial "trap" or self-adjusting mechanical impedance 689. The higher gas pressure in chamber 685 than in 673 causes liquid surface 686 to lie radially outwardly from surface 687 by an amount 688. Centrifugal forces act on the opposed liquid columns to balance the gas pressure difference. Liquor then proceeds into chamber 673, to repeat the above-described absorption cycle. As a result, the absorbing liquor circulates in a closed loop path within the compressor, gas flows into and out of the compressor.

By suitable design of the traps 691 and 689, the compressor of Figure 9 can be made stable against back-pressures higher than that which it can itself produce, thus making it stable against flow reversal, either used alone or when used in parallel.

Rotary inertial thermodynamic compressors of different types can be cascaded. For example, the combination of a liquid-gaseous type, which is stable, with a purely gaseous type, which may or may not be stable, can be a stable device. Also, cascading can be used to tailor the performance of the device to specific operating conditions. For example, an absorptive compressor can be used to feed gas into a gaseous compressor. The waste heat from the heat source for the gaseous compressor can be used to drive the absorptive compressor.

A forepump, viz an auxiliary pump disposed upstream of an RIT compressor, can be used to adjust the operating condition of the compressor. The compressor 723 shown in Figure 10, for example, includes a compressor like that of Figure 8 and a forepump 708. The forepump uses high-pressure vapor flowing through conduit 722 and a nozzle 709 to boost the pressure of inlet vapor 707 to a high enough value to provide for condensation in chamber 711 at a relatively high temperature. The use of forepump 708 thus allows heat to be rejected through impedance Z719 at a higher temperature than that which otherwise would be available.

The forepump 708 preferably is a jet pump including an actuator jet 709 and entrainment and pressure recovery region 710, as is known in the art of jet pumps.

Other types of forepumps can be used.

A forepump also can be used to boost the inlet pressure to similar advantage in an entirely gaseous RIT compressor. This has the additional advantage of maintaining the operating conditions away from the hazardous region near zero flow.

Figure 16 illustrates a compressor 1720 which is essentially the same as the compressor 723 of Figure 10, except that two gases, A and B, are used instead of one.

Gas B condenses at a substantially lower pressure than gas A. Gas A flows in at 1700, is mixed and compressed with gas B in ajet pump 1704. Gas B is compressed in chamber 1705 enough to condense it, and the heat of condensation is discharged through an impedance Z 1712. The compression is not sufficient to condense gas A. The liquified gas B then flows through a "trap" 1707 into a chamber 1708, in which the liquid is heated to evaporate it, The resulting gas drives the jet pump 1704 and repeats the cycle described above.

Vapor Transport Vapor transport can provide low thermodynamic heat flow impedances. For example, vapor, e.g. steam, can be used to heat and spin a RITD 811 illustrated in Figure 11. Vapor is directed through a nozzle 813 against vanes 814 on the RITD to heat and rotate the RITD. Condensate leaves the housing 812 through an outlet 815. The effective impedance to heat flow in such a system depends on the availability of vapor: the availability of large quantities of vapor allows condensation on demand, with low impedance as the result; limited vapor flow restricts the available heat flow and creates a higher impedance.

Internal vapor transport to improve heat transport is shown in Figure 12. Heat entering a chamber 841 at 843 drives vapor from liquid 836. The vapor condenses at a radially-inwardly located surface 835, releasing heat thereto. The resulting liquid condensate returns centrifugally to rejoin the liquid body 836. This process provides the transport of heat in the RITD 830 with low impedance. Heat can be rejected into water or other coolants 840 entering conduit 834 at 831 and leaving via conduit 846, at 832; heat transfer near the rotational axis 1 minimises the rotational drag on the device 830.

Thermodynamic Transformer The invention is used to advantage in a thermodynamic converter or transformer 1249, shown in Figure 13. The transformer 1249 uses heat from a high-temperature heat source 1256 to actuate a RIT gaseous compressor 1250 which pumps compressed gas through a conduit 1251 to condense in a condenser 1252. The condensate liquid proceeds through an expansion valve 1253 to an evaporator 1254 in which the liquid evaporates at a reduced pressure. The resulting vapor flows through a conduitl255 back to the compressor 1250. The heat of condensation flows from the condenser 1252 into the load 1261 through an impedance Z1260. Much of the waste heat from the load 1261 returns through an impedance Z1262 to the evaporator 1254 to be used to evaporate liquid.The remaining waste heat can leave from the evaporator through an impedance Z1259 or from the load through an impedance Z1263, as is appropriate to the process. The temperature difference between the condenser 1252 and the evaporator 1254 is relatively small, so that heat flow to the load 1261 is accompanied by a relatively small temperature drop.

The transformer 1249 makes it possible efficiently to convert a relatively small heat flow from a relatively high-temperature source 1256 into a much larger flow of heat across the relatively small temperature difference between the condenser 1252 and evaporator 1254. This can be used substantially to increase the Carnot efficiency of relatively low-temperature thermodynamic processes when using a high-temperature source of heat. Examples of such processes are the distillation of sea water for desalination purposes, and the concentration of liquid sewage, both of which normally require substantial amounts of heat flow over a relatively low temperature difference. The present invention makes it possible to use a relatively high-grade (high-temperature) heat source such as a nuclear reactor or a fossil fuel fire to actuate the process.

Internal Fuel Combustion Figure 14 shows a gaseous compressor utilizing the internal combustion of fuel to provide the heat for the compression process. A gaseous mixture of fuel and oxidizer (air) enters at 1010 and is ignited by an igniter (not shown). The combustion of the fuel mixture is stabilized by suitable means such as a flame-holding screen 1013.

This combustion directly heats the working fluid and reduces the density of the gas in region 1016 to below that in the region 1012: The operation of centrifugal forces on the gas columns of differing densities compresses the gas, which then leaves the compressor at 1017.

Any heat which must be rejected from the compressor automatically leaves with the gas flowing through the outlet 1017.

The device shown in Figure 14 can be used as an air compressor with a mixture of fuel air as the working fluid. The device also can be used to compress gaseous fuels such as propane or natural gas, by mixing a small quantity of oxidant with the gaseous fuel for use as a working fluid and creating incomplete internal combustion in the manner described above. This process can be used in pumping the gaseous fuel to transport it from place to place, or to liquefy the gas.

Figure 15 shows a cascaded internal combustion gaseous compressor in which fuel is fed to separate stages of the device instead of mixing the fuel with the intake air. The heat of compression in each stage is rejected by means of heat exchangers 1121 and 1108. Heat exchanger 1121 is optional.

Fuel entering at 1103 feeds radially outwardly through ducts 1104 and 1109, to suitable burners 1106 and 1110. Each burner has a preheater with a nozzle 1112, and a flame stabilizer screen 1105. Alternatively, catalytic burners can be used.

By feeding the fuel in separately, the heat of compression in the outgoing conduit sections provides ignition. Other ignition means, not shown, can be used if desired.

The rate of heat production depends on the rate of combustion, and thus on the rate of fuel feed. Feeding the fuel at a fixed rate makes the combustion a high impedance heat source, and this tends to stabilize flow.

Heat Exchangers Heat exchangers which can be used in this invention include not only those having many small parallel tubes, but also porous plugs such as those made out of sintered metal. Both types of heat exchanger can have a relatively high impedance to fluid fluid flow, while providing a low impedance to heat flow into and out of the fluids.

The heat exchangers can be made out of dielectric or other materials suitable to cause them to be heated by electromagnetic induction heating fields, dielectric heating, or the like.

Rotary Drive Means Drive means for spinning the rotors of the foregoing devices include electric and other drive motors of the prior art, as well as the steam turbine type of drive shown in Figure 11. Reaction types of drive means are shown in Figures 14 and 17.

The device of Figure 14 has a jet 1018 with its outlet facing out of the surface of the drawing towards the observer. Part of the compressed gas in the section 1016 is ejected through the jet 1018 to create a reaction force with the atmosphere or other object in the environment. This force spins the loop about the axis 1. Preferably, of course, there will be several loops positioned symmetrically about the axis 1 to balance the rotor.

Figure 17 shows a gaseous single-stage compressor 1731 with another type of reaction drive device 1730. The drive device 1730 includes a member 1735 of magnetic material which is rotatably mounted by means of a bearing 1738 on a rotary shaft 1736 to which the compressor 1731 is connected. A housing 1737 encloses the member 1735 and rotates with the shaft 1736. A stationary magnet 1734 outside the housing 1737 attracts and holds the member 1735 stationary.

A tube 1732 carries compressed gas from location 1741 in the compressor 1731 to a jet nozzle (e.g., a de Laval nozzle) which creates a gas jet and directs it against the member 1735. The jet is directed towards the observer and tangentially with respect to the member 1735. The reaction force developed between the jet and the stationary member spin the compressor 1731 and housing 1737 about the axis 1. The gas from jet 1733 is collected in the housing and is returned to the compressor 1731 by means of a tube 1739, whereby the gas is re compressed.

Various ancillary structures which can be provided by those skilled in this art have not been shown herein for the sake of brevity.

Among such structures are igniters for the internal burning of fuel, and rotary seals for sealing rotating conduits at their junctions with stationary conduits.

WHAT I CLAIM IS: 1. A rotary thermodynamic system comprising a rotary thermodynamic device including at least one fluid flow conduit having radially outwardly-directed and inwardly-directed sections in which conduit -the thermodynamic pressure drop decreases with an increase in the rate of flow of working fluid through said system, and mechanical and/or thermodynamic inipedance control means for providing an increase of pressure drop for an increase in the rate of flow of working fluid through said conduit, the amount of said increase in pressure drop being effective to cause the overall pressure drop for said system to increase with an increase in said rate of flow, thereby stabilizing the flow of working fluid through said conduit.

2. A system as claimed in claim 1, in which the rotary thermodynamic device has a plurality of the conduits connected in parallel, and impedance control means associated with each of the conduits.

3. A system as claimed in claim 1 or 2, in which the rotary thermodynamic device is a heat pump and the impedance control means includes means for extracting heat from the working fluid in the outwardlydirected section of the or each conduit and for supplying heat to the fluid in the inwardly-directed section thereof.

4. A system as claimed in claim 3.

including a positive-displacement pump for pumping the fluid through the rotary thermodynamic device.

5. A system as claimed in claim 4, in which the positive-displacement pump is a reciprocating piston pump.

6. A system as claimed in claim 4, in which the positive-displacement pump is a sliding vane pump.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (44)

1. **WARNING** start of CLMS field may overlap end of DESC **.

   instead of mixing the fuel with the intake air. The heat of compression in each stage is rejected by means of heat exchangers 1121 and 1108. Heat exchanger 1121 is optional.

   Fuel entering at 1103 feeds radially outwardly through ducts 1104 and 1109, to suitable burners 1106 and 1110. Each burner has a preheater with a nozzle 1112, and a flame stabilizer screen 1105. Alternatively, catalytic burners can be used.

   By feeding the fuel in separately, the heat of compression in the outgoing conduit sections provides ignition. Other ignition means, not shown, can be used if desired.

   The rate of heat production depends on the rate of combustion, and thus on the rate of fuel feed. Feeding the fuel at a fixed rate makes the combustion a high impedance heat source, and this tends to stabilize flow.

   Heat Exchangers Heat exchangers which can be used in this invention include not only those having many small parallel tubes, but also porous plugs such as those made out of sintered metal. Both types of heat exchanger can have a relatively high impedance to fluid fluid flow, while providing a low impedance to heat flow into and out of the fluids.

   The heat exchangers can be made out of dielectric or other materials suitable to cause them to be heated by electromagnetic induction heating fields, dielectric heating, or the like.

   Rotary Drive Means Drive means for spinning the rotors of the foregoing devices include electric and other drive motors of the prior art, as well as the steam turbine type of drive shown in Figure 11. Reaction types of drive means are shown in Figures 14 and 17.

   The device of Figure 14 has a jet 1018 with its outlet facing out of the surface of the drawing towards the observer. Part of the compressed gas in the section 1016 is ejected through the jet 1018 to create a reaction force with the atmosphere or other object in the environment. This force spins the loop about the axis 1. Preferably, of course, there will be several loops positioned symmetrically about the axis 1 to balance the rotor.

   Figure 17 shows a gaseous single-stage compressor 1731 with another type of reaction drive device 1730. The drive device 1730 includes a member 1735 of magnetic material which is rotatably mounted by means of a bearing 1738 on a rotary shaft 1736 to which the compressor 1731 is connected. A housing 1737 encloses the member 1735 and rotates with the shaft 1736. A stationary magnet 1734 outside the housing 1737 attracts and holds the member 1735 stationary.

   A tube 1732 carries compressed gas from location 1741 in the compressor 1731 to a jet nozzle (e.g., a de Laval nozzle) which creates a gas jet and directs it against the member 1735. The jet is directed towards the observer and tangentially with respect to the member 1735. The reaction force developed between the jet and the stationary member spin the compressor

   1731 and housing 1737 about the axis 1. The gas from jet 1733 is collected in the housing and is returned to the compressor 1731 by means of a tube 1739, whereby the gas is re compressed.

   Various ancillary structures which can be provided by those skilled in this art have not been shown herein for the sake of brevity.

   Among such structures are igniters for the internal burning of fuel, and rotary seals for sealing rotating conduits at their junctions with stationary conduits.

   WHAT I CLAIM IS: 1. A rotary thermodynamic system comprising a rotary thermodynamic device including at least one fluid flow conduit having radially outwardly-directed and inwardly-directed sections in which conduit -the thermodynamic pressure drop decreases with an increase in the rate of flow of working fluid through said system, and mechanical and/or thermodynamic inipedance control means for providing an increase of pressure drop for an increase in the rate of flow of working fluid through said conduit, the amount of said increase in pressure drop being effective to cause the overall pressure drop for said system to increase with an increase in said rate of flow, thereby stabilizing the flow of working fluid through said conduit.
2. 2. A system as claimed in claim 1, in which the rotary thermodynamic device has a plurality of the conduits connected in parallel, and impedance control means associated with each of the conduits.
3. 3. A system as claimed in claim 1 or 2, in which the rotary thermodynamic device is a heat pump and the impedance control means includes means for extracting heat from the working fluid in the outwardlydirected section of the or each conduit and for supplying heat to the fluid in the inwardly-directed section thereof.
4. 4. A system as claimed in claim 3.

   including a positive-displacement pump for pumping the fluid through the rotary thermodynamic device.
5. 5. A system as claimed in claim 4, in which the positive-displacement pump is a reciprocating piston pump.
6. 6. A system as claimed in claim 4, in which the positive-displacement pump is a sliding vane pump.
7. 7. A system as claimed in claim 1 or 2, in

   which the rotary thermodynamic device is a compressor, and the impedance control means includes means for supplying heat to the working fluid in the inwardly-directed section of the or each conduit.
8. 8. A system as claimed in any one of the preceding claims, in which the impedance control means comprises means for controlling the heat exchange between the rotary thermodynamic device and the environment.
9. 9. A system as claimed in any one of the preceding claims, in which the impedance control means comprises heat exchange means providing multiple heat conducting surfaces in the or each conduit.
10. 10. A system as claimed in any one of the preceding claims, in which the impedance control means comprises a flow-restricting heat exchanger in the or each conduit.
11. 11. A system as claimed in any one of the preceding claims, in which the impedance control means comprises a heat source for heating the working fluid in the rotary thermodynamic device.
12. 12. A systems claimed in claim 11, in which the heat source comprises internal means within the rotary thermodynamic device for generating heat, said internal means comprising decaying radioisotopes, nuclear fission fuel elements, or quantities of chemical substances reacting chemically with one another to generate heat.
13. 13. A system as claimed in claim 11, in which the heat source comprises internal means within the rotary thermodynamic device for generating heat, said internal means including internal combustion means for generating heat.
14. 14. A system as claimed in claim 13, in which the heat source includes ignition means for igniting a combustible fuel, and exhaust means is provided for directing exhaust gases from the device in a direction tending to rotate said device.
15. 15. A system as claimed in claim 11, in which the heat source comprises a source of vaporized liquid including a nozzle for directing said vaporized liquid towards the rotary thermodynamic device in a jet, and vanes are disposed on said rotary thermodynamic device so as to be impinged upon by said jet to rotate said rotary thermodynamic device.
16. 16. A system as claimed in claim 11, in which the heat source comprises a fuel as a working fluid, and an oxidizer, and means for reacting said fuel and oxidizer to produce heat.
17. 17. A system as claimed in claim 16, including means for causing said fuel and oxidizer to flow through the rotary thermodynamic device, and stabilizing means for containing said reaction in a selected portion of the rotary thermodynamic device.
18. 18. A system as claimed in claim 1, in which the rotary thermodynamic device includes at least one portion of said working fluid from which heat is to be extracted, a chamber for containing a liquid, and means for conducting heat from said working fluid portion to said liquid and evaporating the liquid to form a vapor.
19. 19. A system as claimed in claim 18, in which the chamber is at a first distance from the rotational axis of the rotary thermodynamic device, and means for conducting said vapor towards said axis and there cooling and condensing said vapor.
20. 20. A system as claimed in claim 18 or 19, in which the impedance control means includes a liquid trap.
21. 21. A system as claimed in claim 7 or any one of the preceding claims 8 to 20 as appendant to claim 7, in which the compressor includes a compressor section comprising a plurality of the fluid flow conduits connected in series.
22. 22. A system as claimed in claim 21, including a plurality of compressor sections, as defined in claim 21, connected in parallel with one another.
23. 23. A system as claimed in claim 21 or 22, in which the fluid flow conduits of the or each compressor section comprises a single conduit wound into a helix, each loop of the helix forming one conduit or stage of the compressor section.
24. 24. A system as claimed in claim 23, in which one side of each helix loop forms the outwardly-directed section of a conduit and the other side of the helix forms the inwardly-directed section, said outwardlydirected sections together forming a common heat rejection surface, and said inwardly-directed sections together forming a common heat-reception surface.
25. 25. A system as claimed in claim 24, including impedance control means in each helix loop adjacent the radially outermost portion of the inwardly-directed section.
26. 26. A system as claimed in claim 23, 24 or 25 as appendant to claim 22, in which the helices of the parallel compressor sections form a toroid about the rotational axis of the device, said helices being symmetrically positioned about said axis.
27. 27. A system as claimed in claim 7, in which the outwardly and inwardly-directed sections of the or each conduit are thermally coupled together through a relatively low thermodynamic impedance, the outwardly-directed section and the radially innermost portion of the inwardlydirected section each present a relatively high thermodynamic impedance to the flow of heat from the working fluid therein to the external environment, and the heat supplying means is located adjacent the radially outermost portion of said inwardlydirected section.
28. 28. A system as claimed in claim 3, in which the heat pump has a liquefiable working fluid and said heat pump is adapted to liquify said fluid adjacent the outwardlydirected section of the or each conduit and evaporate the liquefied fluid adjacent the inwardly-directed section thereof, and a further section interconnects the first two sections and extends radially outwardly therefrom to form a trap.
29. 29. A system as claimed in claim 7, in which the compressor has a liquefiable working fluid and is adapted to liquify said fluid adjacent the outwardly-directed section of the or each conduit and evaporate the liquefied fluid adjacent the inwardly-directed section thereof, and a further section interconnects the first two sections and extends radially outwardly therefrom to form a trap.
30. 30. A system as claimed in claim 3, in which the impedance control means includes an auxiliary pumping device upstream of the heat pump.
31. 31. A system as claimed in claim 7, in which said impedance control means includes an auxiliary pumping device upstream of the compressor.
32. 32. A system as claimed in claim 1, including a closed loop conduit, means for absorbing a gas in an absorbent liquid, flowing the resulting liquor radially outwardly through the outwardly-directed section of said closed loop conduit, heating the liquor and driving off said gas, pumping the gas and absorbent liquid separately through the inwardly-directed section of the conduit to a radially inwardly located position, and flowing said liquid through a liquid trap constituting impedance control means to a position to absorb more gas.
33. 33. A system as claimed in claim 7 for thermodynamic transformation, including a relatively high-temperature heat source supplying heat to the compressor, a condenser, means for conducting compressed working fluid from said compressor to said condenser, an evaporator means for conducting liquid working fluid from said condenser to said evaporator, and for conducting gaseous working fluid back to said compressor, said condenser being adapted to condense said working fluid at a first temperature, and said evaporator being adapted to evaporate said working fluid at a second temperature below said first temperature, the temperature difference between said heat source and said compressor being substantially greater than that between the condensation and evaporation temperatures of said condenser and evaporator.
34. 34. A system as claimed in claim 33, including a load thermally coupled to receive heat from the condenser and reject heat to the evaporator.
35. 35. A system as claimed in claim 33 for water desalination, including a water evaporator and condenser thermally coupled to receive heat from the condenser and reject heat to the evaporator.
36. 36. A system as claimed in any one of the preceding claims, including means for rotating the rotary thermodynamic device comprising a magnetic member rotatably mounted within said device, a stationary magnet outside said device and adjacent said magnetic member, and means in said device for developing a fluid stream and directing said stream against said magnetic member.
37. 37. A method of stabilizing the operation of a rotary thermodynamic system comprising a rotary thermodynamic device including at least one fluid flow conduit having radially outwardly-directed and inwardly-directed sections, there being a decrease in the pressure drop in said conduit with an increase in the rate of flow of working fluid through said conduit, said method comprising controlling the mechanical and/or thermodynamic impedance in said system so that therein an increase in pressure drop for an increase of the flow rate of working fluid through said system, said increase being greater than said decrease so as to give said system an overall pressure drop which increases with increases in said flow rate.
38. 38. A method as claimed in claim 37 for liquifying a combustible gas, comprising oxidizing a portion of said gas in the rotary thermodynamic device, which is arranged as a compressor, to supply heat for operation of said compressor whilst simultaneously compressing said gas, and then condensing the compressed gas.
39. 39. A method as claimed in claim 37, including driving a heat-operated rotary thermodynamic device by generating operation heat within said device and using at least some of said heat to form a fluid into a flowing stream, and reacting said stream with the outside environment to develop reaction forces tending to rotate said device.
40. 40. A method as claimed in claim 39, in which said heat generating step comprises producing an exothermic chemical reaction within said device.
41. 41. A method as claimed in claim 40, in which the exothermic chemical reaction comprises oxidation of a fuel.
42. 42. A method as claimed in claim 37, including the cooling of a surface from which heat is to be removed in the rotary thermodynamic device, said method comprising the steps of conducting heat from said surface to a body of vaporizable liquid and thereby vaporizing said liquid, and cooling the resulting vapor to condense it.
43. 43. A method of stabilizing the operation of a rotary thermodynamic system, substantially as hereinbefore described with reference to any one of Figures 2 to 17 of the accompanying drawings.
44. 44. A rotary thermodynamic system constructed and adapted to operate substantially as hereinbefore described with reference to any one of Figures 2 to 17 of the accompanying drawings.