FR2485085A1 - THERMODYNAMIC MACHINE - Google Patents

Abstract

THERMODYNAMIC MACHINE WITH A FLUID WORKING CIRCUIT WORKING IN THE LIQUID-VAPOR PHASE BETWEEN A HOT SOURCE AND A COLD SOURCE, INCLUDING A MOTOR FOR USING THE GASEOUS PRESSURE OF THE FLUID INTERCALED BETWEEN THE HOT SOURCE AND THE COLD SOURCE, AND A COMPRESSOR MEANS OF FORCED FLUID CIRCULATION IN THE WORKING CIRCUIT DRIVEN FROM THE SAID MOTOR OF USE, CHARACTERIZED IN THAT THE AUDIT WORKING CIRCUIT IS ASSOCIATED WITH A REFRIGERANT CIRCUIT WITH REFRIGERANT FLUID WORKING IN THE FLUID-VAPOR PHASE COOPERATING WITH THE COLD SOURCE EXCHANGER OF THE WORKING CIRCUIT, WHILE THE HOT SOURCE EXCHANGER OF THE WORKING CIRCUIT COOPERATES WITH AN ENVIRONMENT THAT CAN BE ONLY THE ATMOSPHERE OR OF A HIGHER TEMPERATURE THAN THIS LAST FRIDGE CIRCUIT, THE FRIGORIFIC CIRCUIT MEANS OF FORCED CIRCULATION OF THE REFRIGERANT FLUID ALSO DRIVEN FROM THE SAID ENGINE.

Description

The invention relates to a thermodynamic machine with a working circuit.

  with fluid working in liquid-vapor phase between a hot source which can be only the atmosphere and a cold source created, according to a new conception, using the machine itself, of purely operating principle

  thermal based on the borrowing of calories from the atmosphere

  before being increased, if necessary, by harnessing solar energy

  air or by external combustion of additional input, which leads to eliminating or reducing the consumption of chemical energy as well as the usual resulting pollution in applications

  especially motor or refrigeration machines.

  Essentially, from this effect, the thermodynamic machine

  according to the invention, comprising a working fluid working circuit

  working in liquid-vapor phase between a hot source and a cold source, comprising a motor for using the gaseous expansion of the fluid interposed between the hot source and the source

cold each comprising an exchanger, and circulating means

  forced tion of the fluid in the working circuit driven from

  shot of said engine of uses is characterized in that it is associated with said working circuit a refrigerating circuit with refrigerant working in liquid-vapor phase to create a

  cold source cooperating with the cold source exchanger of the circuit

  cooked for work, while the hot spring heat exchanger

  work cooked cooperates with an environment that may only be the

  mosphere or higher temperature than this, said refrigeration circuit comprising means for forced circulation of the refrigerant also driven from said engine. The invention also extends to an embodiment

  particular of the refrigeration circuit, while the choice of refrigerants

of in the two circuits also conditions its optimization

as we will see later.

An embodiment of a thermodynamic machine

  according to the invention is moreover hereinafter described, by way of

  example, and with reference to the accompanying drawing, in which: - Figure 1 is a schematic view of a working circuit of the thermodynamic machine according to the invention; - Figure 2 is a temperature-pressure diagram of

2 2485085

  the evolution of the working circuit fluid during a complete cycle;

  - Figure 3 is a schematic view of a fri-

gorific of the thermodynamic machine according to the invention; - Figure 4 is a temperature-pressure diagram of the evolution of the refrigerant during a complete cycle; - Figure 5 is a partial illustrative diagram of a variant of the working circuit cycle; - Figure 6 is an entropy diagram of the cycles of

  working circuit and refrigeration circuit illustrative of the

  dement of a thermodynamic machine according to the invention.

  The working circuit of the machine object of FIG. 1 comprises an exchanger 1 constituting the cold source of this circuit

  and wherein the working fluid is intended to be liquefied.

This exchanger 1 is placed in an enclosure 2 constituting the

  cold source of a refrigeration circuit which will be described later.

  The working circuit includes another 3-way exchanger

  mant evaporator and cooperating with the atmosphere.

  Between the exchanger 1 and the exchanger 3 are arranged a valve 4 followed by a pump 5 intended to pump the liquefied fluid

  to inject it under a certain pressure in the exchanger 3.

  Between exchanger 3 and exchanger 1 are arranged

  a storage tank 6 of pressurized gaseous fluid, a valve 7, a turbine 8 constituting the operating motor and a pressure regulator 9 opening directly into the exchanger 1. The turbine 8 is used in particular to drive the pump 5. Initially the valves 4 and 7 are closed and the circuit is loaded with gaseous ethylene under pressure in its part including the pump 5, the exchanger 3

and the storage tank 6.

  The cold source being considered established, the function

operation of the machine, for which valves 4 and 7 are mid

  its in the open position, takes place in the working circuit

  vail according to the cycle object of the temperature-pressure diagram of FIG. 2, the temperature T y being expressed in degrees Kelvin and the pressure P in bars. This cycle is established by way of example for ethylene (C2H4) chosen as working fluid among other possible, and for a maximum pressure of 30 bars in the flask, the possible excess of which can be derived by the route a relief valve 10 on the pipe 11 interposed between turbine 8 and regulator 9, this pipe II being able to comprise

  a non-return valve preventing any discharge to the tur-

bine when valve 7 is closed.

  The expansion phase considered adiabatic of the ethylene admitted into the turbine 8 from the accumulator ball 6 to its passage in the regulator 9, at the outlet of which it relaxes along the portion BC, has been shown from A to B. of its curve

  of liquefaction L, entering the exchanger 1 of cold source

  from, where it will be entirely liquefied according to CD and brought E D to a temperature lower than that of its liquefaction temperature under the prevailing residual pressure, which is the temperature corresponding to point C.

  This temperature in D depends of course on the temperature

  erasure reached in enclosure 2 of cold source and the diagram

  me of figure 2 is established here for a cold source obtained

  using Xenon under 1 bar, which corresponds to a temperature

erasure of 1650K.

  The ethylene thus liquefied is then discharged by the

pump 5 under a certain pressure in the exchanger 3, this amount

  pressure tee corresponding to phase DE of the diagram. In exchanger 3, the liquefied ethylene is then heated by the

  calories captured from the atmosphere by the exchanger, and its temperature

  ture in the liquid phase rises according to the illustrated phase from E to F, while from this last point F placed on the liquefaction curve L, the ethylene is vaporized in the exchanger 3 and here considered to be heated to constant volume according to the illustrated phase from F to A, where we find ourselves at the initial point A of the cycle corresponding to the state of the ethylene gas in the storage tank 6 (a diagram with heating at constant pressure would pass through D, El, A, the practical diagram being established between

both).

  To stop the operation of the working circuit, the valve 7 is closed first and the liquid ethylene present in the exchanger 1 is exhausted using the pump, to the exchanger 3 and the flask 6, where the ethylene remains stored

  in the gas phase, after closing valve 4. This reconditioning

  ment of the circuit is provided with the use of external energy to drive the pump 5 due to the shutdown of the turbine 8, the time required for a simple volumetric pumping of the quantity of liquid ethylene present in the exchanger 1, so that after a predetermined timed actuation of the pump 5 the valve 4 can be closed and the working circuit returns to condition

initial startup.

  This external energy can be taken outside the

machine or taken from storage means associated with it

ci and charged by levy on the work of the turbine (such as accumulator batteries supplying an electric motor driving the pump) An energy balance of such a cycle

  will be explained later after description of the refrigeration circuit

creator of the cold spring.

  The refrigeration circuit of the machine object of 3 figure

  3, with refrigerant working in liquid-vapor phase,

  takes a storage tank 12 of pressurized gaseous fluid

  which is connected by a conduit 13 provided with a valve 14 to a deten-

  deur 15 opening into the enclosure 2 of cold source.

  The vapor phase of the latter is sucked in through the

  medium of a duct 16 and of a compressor 17, which recompresses it

me to pass it through a valve 18 and a con-

duit 19 through an exchanger 20 disposed in the enclosure 2 and whose outlet conduit 21 opens into the latter by a

regulator 22.

On a conduit 23 connecting the valve 18 to the accumulated balloon

  compressor 12 are also arranged a compressor 24 followed by an exchanger

  geur 25 immersed in the atmosphere.

The valve 18 is a two-position selection valve comprising: a position I for placing the compressor 17 in communication with the duct 19 towards the exchanger 20 (that shown in the drawing)

  - and a position II of communication of the compressor -

sor 17 with the duct 23 to the additional compressor 24 (that obtained by a rotation indicated by the arrow F in the drawing) The operation of this refrigeration circuit is described below using the temperature-pressure diagram in FIG. 4, corresponding to the use of Xenon as a refrigerant, assuming that initially the valve 14 is closed, the valve 18 is in position I, and that the xenon in the gaseous state is stored under a pressure of approximately 10 bars, at the atmospheric temperature of approximately 2901K, in the tank 12, in fact in the circuit part between the valves 18 and 14 including the exchanger

and ball 12.

  By opening the valve 14, the Xenon gas from the tank 12

  comes to regulator 15 o it relaxes according to the portion of adia-

  batique A, Bx followed by the BxCx portion of its L-curve

  faction, which here corresponds approximately to a 50% liquefaction (ratio of AI Cx on ordinate of AI) the residual gas phase

  being pumped into enclosure 2 by compressor 17 which recom- mends it

  prime according to CxDx, by sending it to the exchanger 20 o it is here considered to be cooled to constant volume along the portion of curve DxBx in the diagram, before being expanded again in

  the regulator 22 along the portion BxCx of the liquefaction curve

  tion L, where it is then still liquefied by about 50% 0 (cooling at constant pressure would cause the diagram to pass through DxBl, BxCx, the practical diagiamuoe being established between the two) This operation thus continues according to the BxCxDx cycle with gas phase influx from balloon 12 according to the cycle ABxCxDxBxCx until valve 14 is closed to

  leave only the BxCxDx cycle maintained by the

compressor 17.

To stop with the machine running,

  working cooked understood as already explained, the operation of the refrigeration circuit, the valve 18 is passed to position II of connection of the compressor 17 on the additional compressor 24 which compresses the gaseous phase of the Xenon until its liquid phase is exhausted in the enclosure 2, by heating it along the portion of adiabatic CxDxE of FIG. 4, while it is then cooled in the exchanger 25 to accumulate in the tank 12 at room temperature along the portion of the curve

  EA returning to the starting point of the cycle, the valve 18 being oar-

  born in position I at the end of this phase to maintain the circuit portion including the tank 12 and between valves 18 and

14 in gaseous phase under pressure.

  This reconditioning of the refrigeration circuit is also planned with the use of external energy to drive the

  compressors 17 and 24 due to the shutdown of turbine 8, up to

  that, for example, the pressure in the enclosure 2 of the cold source has fallen to a value corresponding to the absence of liquid Xenon. This energy can be taken as indicated in

  during the presentation of the work circuit reconditioning.

  An energy balance of the two circuits can be established as follows: In the diagram in Figure 2, the useful work from A to B is given by the formula: w = (-1) T (1 - PO (calories / mole) with y equal adiabatic exponent ap (heat ratio Cv

  mass at constant pressure and volume), To the cor-

  corresponding to p. at A and p the pressure at B. Since t 'can vary between 1.1 and 1.7, it is preferable to choose a fluid with small X. Ethylene, for example, has a y of 1.255 in the zone of pressures and temperature involved, corresponding to a Cv of

8.5 cal / mole.

  If we choose that the useful work is done with a residual pressure of 4 bars, and if the ambient temperature is

  of 2900K, the useful work will be of the order of 700 (calories / mole).

  (It is obviously also given by W = 2 (t T) (calories per mole) (X-1) with A T the temperature difference between A and B) We must subtract from this, the work necessary to compress the ethylene and the work required to maintain the

cold source.

  The work required to compress ethylene is given by: 1 Q = t Molecular mass 10 (calories) p density 4.18 with A p in bars from D to E the molecular mass in grams the density in grams / cm3

  As the molecular mass of C 2H is 28 and the den-

  site of the liquid is estimated at 0.756 g / cm3, we obtain Q = 30 (calories per mole) Much more important is the work necessary to maintain the cold source whose cycle is given in Figure 4 in the case of Xenon. As the Y of the Xenon is at least 1.6, the gaseous adiabatics are given by: Ipp 0.375 T = To If we use the BxCxDx cycle only 50% of the Xenon is liquefied. As the heat of vaporization of Xenon is 3,000 calories per mole, the cold source can recover 1,500 calories per mole of Xenon without changing the temperature. To obtain these 1,500 calories, it was necessary to refrigerate the Xenon from Dx to Bx which

  cost 288 cal / mole (Cv is at most 3.31).

  As we get these calories from the cold source, it

  only 1212 available (calories / mole).

  It was also necessary to compress the gas from Cx to Dx which dennnd3

320 cal / mole of Xenon.

  As in the ethylene cycle, ethylene is mine-

  tie liquefied and its heat of vaporization is 3.250 (cal / mole), it will be necessary to give, to liquefy the ethylene completely,

  1.625 (cal / mole of ethylene) at the cold source.

  The flow rate in moles of the cold source should therefore be approximately 1.4 moles of Xenon per mole of C2H4. The work of compressor 17 of the cold source will therefore be 448

cal / mole of C2H4.

  Each mole of C2H4 producing 700 working calories,

  but this production requires (448 + 30 = 478) calories of e-

  vail, the useful net work will therefore be approximately 220

calories per mole of C2H4.

For the first start-up of the machine, it may suffice, the valves of the two circuits being in the off position, to fill each circuit with corresponding gas

  under pressure via the respective valves 26 and 27-

  provided on balloon 6 and balloon 12, then put the

  valves in machine operating position.

  Then the machine can be restarted-after

  stop reconditioning according to the procedures already set out.

  It is therefore possible with a thermodynamic machine according to the invention to create a refrigerating machine, or a motor, or a combination of the two, without using energy other than that taken from the atmosphere and while having working pressures which can be easily between 20 and 40 bars in particular.

  When used as a motor, the cold source part

  of the two circuits will of course be carefully insulated

  to avoid losses in its place.

  When used as a refrigerating machine, the

  girdle 2 of cold source will constitute part of itself to the

  minus the role of the usual evaporator in a refrigeration machine.

  Of course, the engine of use is not necessarily a turbine but can also be a piston engine with distribution by usual valves, mono or polycylindrical for example, with intake manifold receiving the fluid under pressure from balloon 6 and manifold exhaust connected to the regulator 9 of the

job.

  Optimizing such a machine leads to the consi-

  following derations: For the working circuit, it will be advantageous to use a fluid with a low heat of vaporization with ab

weak, as already indicated.

  For the cold source circuit we will have interest in

  contrary to using a fluid having a vaporizing heat

strong with Y strong.

  In particular if we want to minimize the expense of energy

mechanical W in compressor 17, choose a gas

  whose Y Cp ratio is high, which amounts to a small C.

CV

  The Y range from 1.1 (C fk20 cal / mole) to 1.7 (C X 5 cal / mole).

  p p Such a variation has a considerable effect on W.

  From this point of view, the Argon, Neon, Xenon, Kryp- family

  your tone is interesting since these gases have Y between 1.6

and 1.7.

2 485-085

  Xenon is all the better as its vapor heat -

sation is 3,000 cal / mole.

On the other hand, the vaporization temperature of the fluid in the working circuit must be higher than that of the fluid in the cold source circuit, this being to be taken into account since the smallest pressure in the two circuits has

you don't have to be the same. So that we can increase rela-

  the vaporization temperature of the working fluid in

keeping it under a certain pressure above the atmosphere

  re. Part of the liquefaction is lost, so that the sour-

  this cold should be able to recover more heat.

  It would also be beneficial to increase the lowest pressure of the cold source circuit so that the volume necessary for this

  circuit is minimized. But this goes against the previous desire

tooth.

  In the main use of the machine as a motor, it would be beneficial to increase the temperature difference between B and A (figure 2) but this is only possible by choosing B closer to C, that is ie by decreasing the percentage of active fluid liquefied in C, as long as the ambient temperature remains

be close to 3000K.

  In the case of using the machine as a refrigerating machine, it will be advantageous to adopt for the working circuit

  a diagram such that the turbine-8 only produces the ne-

  stop driving the pump 5 and the compressor 17, and

  the possible storage of reconditioning energy, and in the-

which point B will be chosen as high as possible on the liquefaction curve, taking into account the maximum pressure chosen in A. But we can also use a hot source at a temperature higher than that of the atmosphere, in particular by application or concentration of solar energy, by external combustion or recovery of any heat, applied to

exchanger 1 of the working circuit or to an additional exchanger

  shut up between the latter and the storage tank 6,

  to work in particular at higher temperature.

  As current liquid pumps are suitable for working at pressures much higher than previously

indicated, it will be preferable to modify the work cycle

  vail illustrated in Figure 2 as shown in Figure 5, as to

the upper part of the diagram, the new points of it

  these being designated by the same reference letters assigned with

the index "prime", and the lines T and T 'corresponding respectively-

  at room temperature and higher

viewed from the hot spring.

  We see on this diagram that we compress the ethy-

lene liquid from E to E '.

  Without this overcompression, which costs little work, the curve starting from the level EF and passing through A would lead to A ", while with it the curve passing through the level E'F 'will lead to A', which can in particular be chosen so as to be higher on the same adiabatic as that passing through A, that is to say without modifying the point B of figure 2, chosen according to

  previously discussed considerations.

  An example is given in Figure 6 of an entro-

stings for the two fluid circuits, with ethylene in the working circuit and with Xenon in the refrigeration circuit, this diagram making it possible to assess the efficiency which can be expected from a

such machine.

  In this diagram, (T, S) for the two fluids (C2H4 and Xenon) (Figure 6), the ethylene cycle is the cycle (A, B, C, D, E, F, F, A) while that the Xenon cycle is the cycle (Dx, Bx,

Cx, Cx, Dx).

AB is the useful expansion of ethylene.

  BC corresponds to the expansion along the liquefaction curve.

  CD corresponds to the cooling of the ethylene from its temperature

  liquefaction to that of Xenon.

DE corresponds to the pumping of liquid ethylene.

  EF corresponds to the heating of this liquid.

FF corresponds to its vaporization.

  FA corresponds to the heating of the gas.

The band "Ambient temperature" shows you when to intervene the possible auxiliary hot source which will heat

  gas from this ambient temperature to the corresponding temperature

1l corresponding to A. For the Xenon cycle, the segment (Cx-Cx) corresponds to the evaporation of Xenon in the cold source, the segment (CxDx)

  corresponds to the compression of the Xenon gas, the segment (Dx-Bx) cor-

responds to cooling, the segment (Bx-Cx) corresponds to the de-

tries along the liquefaction curve.

The cycles are given for 1 mole of ethylene therefore for

1.4 moles of Xenon and that is why the simulated heat exchanges

  (D-C) and (Cx-Cx) are equal.

  Useful work is represented by the area (A, B, C, D, E, F, F, A) minus the work required by the refrigerant circuit, i.e. the hatched area (Dx, Bx, Cx, Cx, Dx) , while Carnot's yield would be: ILJ [1 - Area (EZXY)] = 50%, c = - A re (WAXY)

  the theoretical efficiency of the engine is only: 16.3%.

  But all or most of the heat is

given by the ambient air which costs nothing.

  Of course, various embodiments can be

  envisaged for the two working circuits and associated refrigeration

  of the machine according to the invention, without, however,

  get out of the domain of the latter.

Claims (11)

  1. Thermodynamic machine with fluid working circuit working in liquid-vapor phase between a hot source and a cold source, comprising a motor for using the gaseous expansion of the fluid interposed between the hot source and the cold source each comprising an exchanger , and means of circulation   forced tion of the fluid in the working circuit driven from   shot of said use engine, characterized in that it is associated   linked to said working circuit a refrigerant circuit with fri-   genogen working in liquid-vapor phase to create a cold source cooperating with the cold source exchanger of the working circuit, while the hot source exchanger of the working circuit cooperating with a medium which may be only the atmosphere or   higher temperature than the latter, said fri-   gorific comprising means for forced circulation of the fluid refrigerant also driven from said use engine   tion. 2. thermodynamic machine according to claim 1, characterized in that the working circuit fluid has an expo-   adiabatic health (t) lower than that of the circuit fluid refrigerated.   3. Thermodynamic machine according to one of claims   above, characterized in that the heat of vaporization of the working circuit fluid is relatively low compared to   to that of the refrigerant circuit fluid.   4. Thermodynamic machine according to one of claims   previous, characterized in that the refrigeration circuit   takes a cold source enclosure, a compressor drawing the gaseous refrigerant from the enclosure and returning it to an exchanger inside the enclosure, and a regulator opening into the enclosure and connected to the outlet of said interior exchanger. 5. thermodynamic machine according to claim 4,   characterized in that the refrigeration circuit includes a tank   see pressurized gaseous refrigerant accumulator connected via a start-up control valve to a regulator opening into the cold source enclosure, and a selection and stop control valve intended to interrupt communication between said compressor and the interior exchanger, to connect this compressor to a complementary compressor which is   connected to said accumulator tank via an exchanger   geur bathing at least in the atmosphere.   5. Thermodynamic machine according to claim 1, characterized in that the means of forced circulation of the working fluid consist of a pump of the liquefied phase of the latter leaving said cold source.   7. Thermodynamic machine according to claim 6, characterized in that the pump delivers in said exchanger of   hot spring followed by an accumulator of working fluid   pressurized gas which is connected to the intake of the operating engine, the outlet of which is connected by a pressure reducer to said cold source exchanger, and that two isolation valves are respectively provided, on the one hand between this latter tank and the engine of use and, on the other hand, between the cold source and said pump.   8. Thermodynamic machine according to claim 7, characterized in that a relief valve is provided between   the accumulator tank and a conduit connecting the utility motor regulator reading   9. Thermodynamic machine according to one of claims   previous, characterized in that the working circuit fluid is ethylene.   10. Thermodynamic machine according to one of claims   above, characterized in that the refrigerant is Xenon.   11. Thermodynamic machine according to claims 1, , 6 and 7, characterized in that the aforementioned pump and the compressors are subjected to auxiliary drive means brought into play   when the machine stops to recondition each circuit in fluid   pressurized gas in its part including said accumulator tank. 12. The application of a thermodynamic machine according to   one of the preceding claims, as a mechanical energy source by its engine of use.   13. The application of a thermodynamic machine according to one of the preceding claims, as a refrigerating machine,   via the cold source of the refrigeration circuit.