DE3150900A1 - Method for converting heat energy into mechanical energy - Google Patents

Abstract

The invention relates to a method for converting heat energy into mechanical energy, in which a fluid is heated within a closed circulation system, in the process is raised to a high pressure, and is allowed to expand, performing work in the process. If the condensation is carried out against cooling water, the choice of the type of fluid is restricted since, for example, it is not possible to use a fluid, the condensation temperature of which is below the given temperature of the cooling water. A similar statement applies to the evaporation of the fluid. In order to make possible the use of a multiplicity of fluids, the invention proposes that the expanded fluid be taken up by a sorbent and that fluid-laden sorbent be regenerated, the supply of further fluid to the sorbent during the regeneration of desorbed fluid being fed under high pressure to the work-performing expansion again.

Description

Process for converting thermal energy into mechanical energy The invention relates to a method for converting thermal energy into mechanical energy Energy in which a fluid heats up within a closed circuit system, is brought to a high pressure level and relaxed while doing work.

In the case of steam power plants, this is used for relaxation in an expansion machine necessary pressure gradient due to heating, i.e. evaporation and possibly overheating of the fluid of a circulatory system before the expansion machine and by condensation of the fluid after the expansion machine is maintained. Usually the Condensation carried out against cooling water. This gives you the choice of the type of fluid restricted, since, for example, no fluid can be used, its condensation temperature is below the given cooling water temperature. The same applies to evaporation of the fluid. The position of the boiling point is often particularly unfavorable, around To be able to use waste heat at a low temperature level.

The invention is therefore based on the object of providing a method of initially characterized to indicate the use one Allows for a variety of fluids.

According to the invention, this object is achieved in that the relaxed Fluid absorbed by a sorbent and regenerated loaded sorbent being supplied with further fluid to the sorbent during regeneration is prevented and the fluid released during regeneration under high pressure is again led to the work-performing relaxation.

According to the invention, in a method in which a fluid evaporates, possibly brought overheated to a high temperature level and subsequently performing work is relaxed, the previously common process step of condensation of the relaxed, vaporous fluid replaced by a process step in which the fluid of is absorbed by a sorbent. Relaxed fluid is absorbed as long as until the sorbent is loaded. Then the supply of more fluid interrupted to the sorbent.

The sorbent is now regenerated. Desorbed during regeneration Fluid is either fed directly to the work-performing relaxation, or if so the pressure of the desorbed fluid is below the high pressure level, to the high Pressure level brought and then relaxed while doing work.

The method according to the invention advantageously offers the possibility of to be able to choose from a variety of fluids and one for the given application to find a suitable fluid. According to the invention one is no longer dependent on the pressure gradient necessary for an economical energy conversion through evaporation and to maintain condensation. Rather, it is without these procedural steps possible to achieve high working pressures even with a small temperature gradient. This property is particularly interesting for the use of Waste heat. According to the invention, the heat source is not used for evaporation, but to regenerate the loaded sorbent.

On the other hand, what was previously required to condense the fluid is used Coolant to the sorbent regenerated at a relatively high temperature to cool the loading temperature required for renewed sorption of the fluid.

In an advantageous embodiment of the inventive concept the fluid released during the regeneration of the sorbent is stored until the pressure of the stored fluid corresponds to the high pressure level. Afterward the fluid is supplied to the work-performing relaxation. That way you can the desorbed fluid can be relaxed immediately to perform work without first to have been compressed or heated.

In a further embodiment, according to the invention, it is also advantageous the fluid is again supplied to the work-performing relaxation that occurs during regeneration has not been desorbed at a high pressure level. This is done by the sorbent after regeneration at high pressure level, regenerated to release pressure level and the fluid that is released in the process is brought to the high pressure level. The sorbent is thereby largely freed of fluid and is suitable for renewed sorption of the Fluids ready after its work-performing relaxation.

In a variant of the inventive concept, the fluid is from a Adsorbent added. In this case, the adsorber can also function of the steam boiler of previous systems: As soon as the adsorber is loaded and the supply of further fluids is blocked, this can be re-controlled, whereby Fluid provided at a high temperature and pressure level and relaxed while performing work will can.

The adsorbent heated during desorption is expediently cooled before fluid is adsorbed again, as this increases the absorption capacity of the adsorbent is increased.

In principle, it is possible to use the method according to the invention with only to operate an adsorber. In this case there is only an intermittent conversion from would be possible in mechanical energy. In an expedient embodiment of the The inventive idea that enables continuous operation is therefore the relaxed fluid in one of at least four, in particular five periodically switchable Adsorbers added, while the remaining adsorbers are regenerated.

In another advantageous variant of the inventive concept the fluid taken up by an absorbent. Here it proves to be advantageous that the liquid absorbent can be pumped as well as loaded with fluid Absorbent from the absorber to the expeller as well as an absorbent freed from the fluid from the expeller to the absorber.

For a continuous procedure it is in an advantageous, Embodiment according to the invention useful if the loaded absorbent into one of several, in particular five, periodically changeable expellers is introduced while the absorbent regenerates in the remaining expellers will.

So that a very large amount of (ntìpanntlem Fluid can be absorbed, it is advantageous if, according to one embodiment of the inventive concept, the regenerated absorbent is cooled and then is fed to the renewed uptake of fluid.

In another variant of the inventive concept, the fluid can also can advantageously be taken up by chemisorption. In this case it will be sorbent and fluid, however, not separated by physical methods. This is used for example a catalyst bed.

A device for performing the method consists of one closed circuit system, which has a compressor and a downstream one Turbine contains, and is daeT CI ii-i tiit .., tE L fW rt \ sqarj al t, iie tt} h; at least 5 adsorbers are connected via a lockable line each and the adsorbers are two Have outputs, one of the outputs via a lockable line with the turbine on its high pressure side and the other output via one lockable line is connected to the suction side of the compressor This device enables continuous operation with a small number of adsorbers.

This advantage is also achieved with a closed circulatory system, in which a compressor and a turbine are connected in series, that is characterized in that the turbine outlet is connected to an absorber is, which in turn has a lockable line with at least 5 expellers each of the expellers is connected to the high pressure side of the turbine, one with the suction side of the compressor and one via a pump and a cooler output connected to an absorber input via a lockable line owns.

If the fluid is chemically sorbed, it contains a particularly simple one Device for performing this variant of the method, a compressor and a Turbine and is characterized in that the turbine outlet over a catalyst bed with the suction side of the compressor and the compressor outlet via at least two in parallel switched, heatable container is connected to the high pressure side of the turbine, in each of which connecting the vessels to the compressor and the turbine Line a shut-off device is arranged.

The following is intended to use schematic sketches to illustrate exemplary embodiments of the method according to the invention are explained.

In the two figures are greatly simplified devices for implementation of the inventive method shown in Figure 1 with adsorbers and in FIG. 2 a process using an absorber.

According to Figure 1, adsorbers 1 to 5 are connected in parallel. In each Adsorber is installed a flow cross section 28 to 32 for a heat transfer medium. Into a turbine 7 to which an electric generator 27, for example, can be connected can, opens a line 26 on the high pressure side is to the turbine outlet a line 23 is connected, each of which has a connecting line to the adsorbers 1 to 5 branches off. Each connecting line can pass through a shut-off valve 8 to 12 be blocked. In addition to the connecting line, two of the 5 adsorbers open into each of the 5 adsorbers further branch lines that can be shut off by means of shut-off valves 13 to 17 or 18 to 22, respectively. One of the two branch lines of each adsorber opens into a high pressure manifold 24, while the other of the two branch lines each in-a low-pressure manifold 25 opens. The collecting line 24 opens directly into the line 26, while the collecting line 25 is against it connected to a compressor 6, the output of which is also connected to line 26 is.

For an intermittent operation of the plant, a single Adsorber are sufficient. In the exemplary embodiment, the five adsorbers shown however, a continuous operation is achieved. The adsorbers are located here in five different operating states. Each adsorber takes in five successive cycles to each of the five operating states. The respective The operating status is determined by the position of the valves, which are centrally controlled by a control unit can be switched automatically, and by the temperature of the adsorber material certainly. The individual operating states are: I Loading In this operating state are the valves in the branch lines leading to the high pressure accumulator line closed. Relaxed fluid from turbine 7 flows into the adsorber and is there adsorbed. The adsorber is at the loading temperature T1. (Embodiment: Valve 8 open, valves 13, 18 closed, adsorber 1 adsorbs fluid) ..

II Heating As soon as an adsorber is loaded, the valve in the to the line 23 leading connecting line blocked.

The adsorber material is installed in the adsorber by means of a Heated flow cross-section directed heating medium to T2. (Embodiment: Valves 9, 14, 19 closed, heating medium flows through heating coil 29).

III Deliver When the adsorber material is heated, fluid is desorbed. As soon as the high pressure prevailing in line 26 is reached in the adsorber, this is The valve in the branch line leading to the high pressure manifold line 24 is open.

With the high temperature T2, the desorbate becomes the expansion turbine directly 6 out (exemplary embodiment: adsorber 3 is in operating state III, that is, valves 10 and 20 are closed, valve 15 is open.

The desorbate formed when the adsorber material is heated flows from adsorber 3 via valve 15, lines 24 and 26 to the turbine).

IV Residual relaxation The pressure in the adsorber is caused by the high pressure level, the working level of the expansion turbine, lowered to @@@@@ pressure. This will be the valve in the branch line leading to the high pressure manifold line 24 is closed and that in the branch line leading to the low-pressure manifold line 25 is opened. The desorbate released is brought to the working pressure by the compressor. (Example: valves 11 and 16 closed, valve 21 open). Desorbate from adsorber 4 is brought to working pressure by the compressor 6.

V cooling as soon as the whole, yebuilt during the residual relaxation Desorbate is withdrawn from the respective adsorber, the adsorber is at the loading temperature T1 lowered.

For this purpose, a suitable coolant is supplied through the inside of the adsorber installed flow cross-section. There are the valves closed in the branch lines and in the connecting line (exemplary embodiment: Adsorber 5 is cooled, valves 12, 17 and 22 are closed, coolant flows through flow cross section 32).

In the exemplary embodiment, the adsorbers 1, 2, 3, 4, 5 are in the operating state I, II, III, IV and V. For example, a fluid under a pressure of 4 ata occurs at a temperature of 1000C and in an amount of about 14 Nm3 / t adsorber material into the turbine 7 and is expanded there to a pressure of 1 ata. With this Pressure and a temperature of 40 ° C the fluid passes over the opened Shut-off valve 8 in adsorber 1 and is adsorbed there. Adsorber 3 delivers fluid under a pressure of 4 ata and at a temperature of 100 ° C, as well as in an amount of 9.77 Nm3 / t adsorber material This fluid flows through valve 15 and the collecting line 24 directly to the turbine 7. Fluid from adsorber 4 with, for example, a pressure of 1 ata and a temperature of 1000C is used in an amount of 4.23 Nm3 / t adsorber material compressed to 4 ata in compressor 6 and also introduced into line 26.

In the next cycle, i.e. after adsorber 1 is loaded and adsorber 2 is heated up is and adsorbers 3 and 4 have given up desorbate and adsorber 5 has been cooled is, adsorber 5 is loaded (valves 17, 22 closed, valve 12 open). the Adsorbers 1, 2, 3, 4 and 5 consequently take operating states II in this cycle, III, IV, V and I.

In Figure 2, a device is shown schematically through which the relaxed fluid is taken up by an absorbent. Analogous to adsorber operation several expellers 33 to 36 are connected in parallel during absorber operation. In a Absorber 41 open into a line for fluid 43 and a line for low-fluid solvent 42. A line for fluid-rich solvent 44 leads away from absorber 41. from this line branch off to each of the expeller connection lines 45 to 48, each of which can be shut off by a valve 49 to 52. From each of the expellers leads a line 57 to 60, which can be shut off by means of a valve 53 to 56, for the The solvent freed from the fluid is removed and is connected to the suction side of a pump 61 in connection. On the pressure side of the pump 61 is a cooler 62 and on this the Line 42 connected. Furthermore, each expeller is available via a branch line 33 to 66, which can be shut off by means of a valve 67 to 70 with a Low pressure manifold 71 with a compressor 6 in connection. Another branch line 72 to 75 with Valves 76 to 79 open into each expeller and are connected to a high pressure manifold 80 connected. In this high pressure manifold, which is via a separator 81 is connected to the turbine, a line coming from the compressor 6 opens. The amount of liquid formed in the separator 81 is via a line 82 into the Cooler 62 initiated.

Each expeller runs through successive cycles Operating states: I Collect The fluid-rich solvent formed in the absorber 41 is picked up by an expeller until it is filled (in the exemplary embodiment: Expeller 33 takes up fluid-rich solvent. For this purpose the valves 50, 53, 67, 76 closed while valve 49 is open).

II Expulsion As soon as an expeller is filled, the supply of interrupted fluid-rich solvent and heated the solvent in the expeller. For this purpose, there is a lockable flow cross section 37 in each driver to 40 installed, through which a heating medium can be passed (in the exemplary embodiment: Expeller 34 is heated. For this purpose, a heating medium is used through the flow cross-section 38 headed. The valves 50, 54, 68 and 77 are closed).

III Delivery at high pressure Is the high pressure level in the expeller reached, with which the fluid is fed to the turbine 7, the valve in the Branch line leading to the high pressure manifold open and desorbed fluid flows directly to turbine 7. ber 35 the high pressure level has been reached. Valves 51, 55 and 69 are closed, valve 78 is open.

Fluid from this driver flows through lines 74 and 80 to Turbine 7).

IV Low Pressure Delivery Is the solvent at high pressure The valve in the one leading to the high pressure manifold is largely freed of fluid Branch line closed and that in the branch line leading to the low pressure manifold opened. The solvent is now desorbed at the release pressure. Fluid can brought to the high pressure by the compressor 6 and into the high pressure manifold be fed in. However, it is also possible that desorbed at the release pressure Introduce fluid directly into absorber 41 and relax there. (in the example: Valve 70 in branch line 66 is closed, valve 79 in branch line 75 is closed opened. Desorbed solvent is compressed by the compressor 6).

In a further phase and another, not in the drawing From the driver shown, the solvent largely freed from the fluid is carried out by Opening a valve in the line to the cooler 62 withdrawn from the driver, cooled in the cooler 62 and fed back into the absorber via pump 61, to there to absorb the expanded in turbine 7, flowing in line 43 fluid.

As soon as, according to the exemplary embodiment, driver 1 is filled all expellers put into the next operating state. That is, expeller 2 assumes operating state I, expeller 3 assumes operating state II, etc.

The following is a basic assessment of the invention Hot gas work process can be carried out.

Fluid: carbon dioxide heating medium temperature: 100 ° C adsorbent: silica gel Efficiency of the expansion machine: 70% All other losses are neglected.

Amounts adsorbed: 400C, 1 ata 16 Nm / t ads.

1000C, 1 ata 2 Nm3 / t ads.

1000C, 4 ata 5 Nm3 / t ads.

Specific heat capacities: carbon dioxide: c = 0.392 kcal / Nm30C p Silica gel: C = 200 kcal / t ° C. The loading temperature of 400C results from the efficiency 70% when relaxing from 4 ata (100 ° C) to 1 ata.

Amount of heat to be applied per ton for desorbing: QH = (16 x 0.392 + 200) x 60 = 12 376 kcal Amount of heat to be dissipated when cooling the adsorber material per ton: QK = (2 x 0.392 + 200) x 60 = 12 047 kcal difference: 329 kcal / t compaction work: Desorbate 3 Nm 'relaxation gap volume 1.23 Nm3 4.23 Nm3 Nv = 3.1 4.23 = 0.131 KWh ^ - 113 kcal excess: .329-113 = 216 kcal; Efficiency: 216. 100 = 1.75% 12 376

Claims (13)

Claims 1. A method for converting thermal energy into mechanical Energy in which a fluid heats up within a closed circuit system, is brought to a high pressure level and relaxed while doing work, thereby characterized in that the relaxed fluid is taken up by a sorbent and loaded sorbent is regenerated, the supply of further fluids to the Sorbent is prevented during regeneration and during regeneration Desorbed fluid is fed back to the work-performing relaxation under high pressure will. 2. The method according to claim 1, characterized in that in the Regeneration of the sorbent desorbed fluid is stored until the Pressure of the stored fluid corresponds to the high pressure level, and then is fed to the work-performing relaxation. 30 The method according to claim 2, characterized in that the sorbent after desorbing on the high Pressure level also at the release pressure level regenerated and thereby released fluid is brought to the high pressure level. 4. The method according to any one of claims 1 to 3, characterized in that that the fluid is taken up by an adsorbent. 5. The method according to claim 4, characterized in that the desorbing takes place by heating the adsorbent and this is cooled before again Fluid is adsorbed. 6. The method according to claim 5, characterized in that the relaxed Fluid in one of at least four, in particular five, periodically switchable Adsorbers is added, while the remaining adsorbers are regenerated. 7. The method according to claim 1, characterized in that the fluid is absorbed by an absorbent. 8. The method according to claim 7, characterized in that the loaded Absorbent in one of at least four, especially five periodically exchangeable expeller is directed, while the absorbent in the rest Expeller is regenerated. 9. The method according to any one of claims 7 or 8, characterized in that da'das the regenerated absorbent cooled and then the new one Receipt of fluid is fed. 10. The method according to claim 1, characterized in that the fluid is absorbed by a sorbent by means of chemisorption. 11. Device for performing the method according to one of the claims 1 to 6 with a closed circuit system in which a compressor and a Turbine are connected behind the other, characterized in that the output the turbine (7) with at least four, in particular five adsorbers (1-5) each with one lockable line <3-12) is connected and the adsorber has two outlets, with one of the outputs (1-5) via a lockable line (13-17) of the turbine (7) on its high pressure side and the other one via a lockable line (18-22) is connected to the suction side of the compressor. 12. Device for performing the method according to one of the claims 1 to 3 or 7 to 9 with a closed circuit system in which a compressor and a turbine are connected in series, characterized in that the Turbine outlet is connected to an absorber (4), which in turn has one lockable line (45-48) with at least four, especially five expellers (33-36) is connected, each of the expellers one to the high pressure side of the turbine (7), one with the suction side of the compressor (6) and one via a pump (61) and a cooler 62 with an absorber inlet via a line that can be shut off in each case connected output. (72-75, 63-65, 57-60). 13. Device for performing the method according to one of the claims 1 to 3 or 10 with a compressor and a turbine, characterized in that that the turbine outlet via a catalyst bed with the suction side of the compressor and the compressor output via at least two parallel-connected, heatable containers connected to the high pressure side of the turbine, in each of which the vessels with the compressor and the turbine connecting tJeltully indicates a shut-off device; dtieL is