DE653657C - Process for exploiting low temperature gradients - Google Patents

Description

Method of Exploiting Small Temperature Gradients It's from the brain a method has been described which serves to determine an existing temperature gradient to enlarge. In a cylinder a piston is supposed to move back and forth gas pushing from one cylinder side to the other, all in one Heat exchanger is heated. The associated expansion increases the pressure of all gas parts adiabatically and thus their temperature. The ones already through the warmer Gone parts experience a further increase in temperature afterwards about those in the heat exchanger. The reverse process takes place when you do that Cools gas on its way back in a second heat exchanger; here is that Gas assume a lower temperature than the coolant has. The original So the heat gradient has increased.

The wrong conclusion was drawn from this that this retrospective Continuously withdraw the temperature increase or decrease from the gas without any disadvantage and make it usable. This, however, increases as it is through computational treatment can prove that the initial temperature gradient decreases more and more. That is applicable Process only where the original heat gradient is constantly being replenished can. It is therefore suitable for increasing the temperature gradient of heat sources, which flow abundantly, but not because of their insufficient temperature difference are exploitable, e.g. B. in sea water of different depths in tropical areas, in mines between layers of different depths, due to solar radiation or in the wastewater from factories. But even in these cases, the procedure prospect of application only if its effect is intensified.

According to the invention, the effect of the method is enhanced by that a liquid is injected during the heating of the gas, which between the maximum possible difference in the temperature limits in question the vapor tension, evaporated in the later course of the stroke and during the cooling is reflected again.

Helium or another monatomic gas is expediently used as the gas Gas (with a high x) with the highest possible specific heat.

In Fig. I the diagram of an embodiment of the invention is shown. The cold heat transfer medium (temperature T1) flows in line i and the warm one (tempo rature T2) flows into line 2. 3, 3 '. . . 3 '° and 4, 4'. . . 4 "are the cylinders, of which there are two in each of the stages connected in series, the pistons of which are expediently pushed back and forth by a common piston rod 5, 5 ':.. 5". The piston rods must somehow necessarily be connected to one another, e.g. B. be driven by a common crankshaft. The pistons of two successive stages move in opposite directions; so the cranks are offset by 18o °. 6, 6 '. . . are the coolers, i ä through lines ia. . . i received the cold heat transfer medium supplied from line i, which is called ib, i b '. . . 10 flows out of the coolers. 7, 7 '... are the heaters, the lines 2 a, 2 ä . . 2 received fed to the warm heat transfer medium from line 2, which at 2 b, 2 b '... 2 bn flows out of the egg heaters. Check valves 16 or controlled valves are installed so that the gas in the lines only flows in one direction and not back again. A controlled valve must be provided at the points marked with 17 so that the gas does not continue to flow prematurely due to the existing pressure differences.

The operation of the system is as follows: From the cylinder space 3 a the gas flows, e.g. B. helium, through line 8 to the egg heater 7 and the cylinder space 4a. The first gas particles are heated to approximately T2. By warming the subsequent gas particles and the resulting increase in pressure the temperature of the first heated beyond T2, while the last heated arrive at about the temperature T2 in 4a. This process is done by injecting an easily evaporating liquid, e.g. B. ether, preferably towards the end of the Piston stroke amplified, since the resulting steam increases the pressure in 3 a and 4 a and thus the temperatures prevailing therein further increased. This is how it works in the cylinder space 4a to obtain a temperature T2 which is substantially above T2.

During the next piston stroke, the resulting mixture is pressed through line 9 to the other side b of the cylinder: 4, whereby it flows through a heat exchanger io 'attached to the egg heater 7' of the next stage. Here it cools down to about T2 by giving off heat to the mixture in the next stage. During the next piston stroke, the mixture flows through line ii to the displacement 3b, giving off heat to the cold heat transfer medium in the cooler 6. This is also where most of the steam carried along is deposited. Corresponding to the way in which the mixture temperature T2 above T2 is reached during the heating, the temperature Tz 'in the cylinder space 3b is achieved, which is substantially below T1. During the next piston stroke, the gas, which contains only a little ether, is pushed through line r2 to the other side of the cylinder, in which case it extracts heat from the next stage in a cooler located behind the cooler 6 'of the next stage. It warms up to about T1 in order to start its cycle all over again. Of course, the ether precipitated in 6 and 3b is reused in 7. The processes taking place in the second stage are the same as in the first stage; only as a result of the additional heating or cooling in io 'and 13' does the mixture reach temperatures T2 "and 7-1", which are still above T2 or below Ti, and so on in all further stages until the mixture. the last stage is used in a heat exchanger 14 to utilize its temperature from T2rz up to T9 and in a heat exchanger 15 to utilize its temperature from Tln up to T1.

Another exploitation, e.g. B. from T2n down to T1 and from Tin up to T2 without interruption, is unfavorable because of the large temperature changes of the mixture also bring about large changes in pressure. , This would increase the temperature the mixture particles of a displacement that are last to be used beforehand pressed down (when the mixture is hot) or increased (with a cold mixture). A large Part of the achieved increase in the heat gradient would therefore be lost. Because of this is it best to use the mixture only between T? and T2 or Tln and T1 off while for heating, for example, from T1 to close to T2 and for cooling, for example the originally given heat transfer medium is used from T2 to close to T1.

Therefore, in the arrangement just described, there is cooling and The mixture is always heated in two stages, namely z. B. between 4a and 4b and between 4b and 3b, not in a section, i.e. H. that the mixture from 4a through io 'and then 6 to 3b without having passed through 4b-A Another design scheme is shown in Fig. 2. In contrast to the previous it consists of only one stage. The cold heat transfer medium flows in line 18, in 1g the warm one. 2o and 21 are the cylinders. These are directly behind one another and are separated from one another by a wall 24 in which there are closable openings are located. The piston rod moves the two pistons back and forth evenly emotional. 22 is the cooler, 23 is the egg warmer.

The mode of operation is initially the same as in the previous example. Cold gas - at the temperature T is pushed by the piston from the displacement 2o a through the egg heater 23 to the displacement 2 in general, where it is heated and almost saturated with a steam. The temperature peak T2 reached above T2 is not passed on to the second stage as in the previous example, but rather serves to increase the effect in the one that is alone; because it is in the nature of the process that the exceeding of the temperature limits given by the two heat carriers is greater, the greater the given temperature gradient. As can be seen as given upper temperature limit to your first stroke TZ, one will arrive at the cooling in the cooler 22 deeper below T1, as if it were of 7. 2 Get there. in displacement 2o a to Ti. In the second cycle of the mixture, T2 'is exceeded and then Ti is undershot. The cycle is repeated until the desired temperature is reached. This can be either high or low. In Fig. 2 the case is shown in which the high temperature is to be made usable. The scheme for utilizing the low temperature is corresponding. If the temperature is high enough, the three-way lanyard 25 is adjusted so that the hot gas, instead of getting into the cooler, flows off to the point of use. At the same time the wall 24 is closed. In the room 2 1 b, used gas is therefore sucked from the point of use, while the gas in room 2o b, which can no longer flow through the wall 24 to 2 ib, is forced to make its way through the simultaneously open tap 26 and the Take cooler 22 into the cylinder space 2o a. This gas now makes 2.1 after the taps 25 and 26 have been returned to the initial position and the openings in the wall open. the cycle until the desired temperature is reached again.

Here, too, what has already been said applies that the gas is used when it is used must not be cooled down too much. This is why the rooms 2o b and 2i b are also provided. If the gas were to be led back from the point of use directly through 23 to 2o, as a result of the contraction of the gas in the cooler, what has not yet been used would be Expand gas prematurely, i.e. lose energy.

If you want to get a heat gradient to generate power, you can either the warm heat transfer medium from line iy with the cold gas or the cold Let the heat transfer medium from line 18 work together with the warm gas.

In order to achieve a usable amount of gas with every double stroke, the scheme according to Fig. 2 can be developed so that the gas does not circulate several times in one and the same pair of cylinders, but rather passes through several pairs of cylinders each once. This design is illustrated in Figure 3. -The designations 18 to 23 have the same meaning as in the scheme according to Fig. 2: The cylinders here only have one displacement. The combination of two single-acting cylinders to form a double-acting cylinder would have the disadvantage of overflowing heat from the hot parts 21a, 2iä ... to the cold 2oa, 2oä . . ..

On the way from Hubrauin.2o a to 2i a, the gas is heated in the egg heater 23 and enriched with steam, as described above. As a result, it receives a temperature T2 'above T2 in the displacement 2 1 a. The gas then migrates to the cylinder 20, where it is cooled in the cooler 22 and a large part of the vapor is precipitated. The only difference to the previous circuit (Fig.2) is that the gas does not return to cylinder 2o a. The heating effect is exactly the same. The process that took place between 2o a and 21 a is repeated between 2oci and 2i d, only with larger temperature differences of the mixture and so on, until the gas in the cylinder 2o has reached the desired low temperature 7'1't.

From 20 on, the gas is pushed through the line 27 to the point of use, from which it returns to the cylinder 28. From this it is pushed back on the next stroke to cylinder 2o a and then begins its cycle again. The cylinder 28 is necessary because cylinder 20a is emptied at the same time with 2o on and consequently the gas pushed off indirectly by the piston from 2o on from the point of use cannot be immediately taken up by 2o a; cylinder 28 is used for this purpose, but if one wanted to use the hot gas, for example from 2i ä, and direct it from the point of use directly to: 2o a, if necessary, with a cooler switched on in front of it, the aforementioned disadvantageous reaction of excessive cooling would occur . So you also needed a receiving space such as cylinder 28, in which the temperature should be T2, and also a second one, since the first receiving space would work in the same cycle with cylinder 20a and consequently the gas could not be pushed into it directly. It is therefore more advantageous, if the system is to work as a cooling system, to start the process with the lower temperature T1 and, if it is to work as a heating system, with the upper temperature T2. If you look at the above explanations from the point of view of how the gas and the heat behave, you will find the following classification Fig. R: gas remains in the stage, heat migrates; Fig.2: Gas stays in the stage, heat stays in the stage: Fig. 3: Gas migrates, heat migrates. There remains a fourth possibility that the heat remains in one stage and the gas migrates to the next. This then has to deliver the reached temperature peak to the subsequent mixture in the same stage, this again its temperature to the third following, etc., until the desired temperature is reached and the gas heated to this is discharged for use. This occurs one after the other for all levels. The scheme is not to be elaborated on here.

If the heat transfer medium is not available in unlimited quantities, so you can @heat the amounts in the cooler again in the warmer use, and vice versa, e.g. B. in Fig. 2 and 3 the emerging from 23 and 23 ' in 22 and 22 'and those exiting from 22 and 22' in 23 'and z3. But you have to go behind 2z and 22 'then cool the gas with fresh heat transfer medium, behind 23 and 23' continue heating with fresh heat transfer medium.

In the higher stages it can happen that at the beginning of the stroke the gas enters the heater or cooler at a temperature which is significantly below T1 or above T. If you want to take advantage of this, you have to use the gas before it z. B. enters the heater 7 ', 7 ". 7n or cooler 6', 6" ... 6n (Fig. Z), preferably small upstream heat exchangers flow through, which, if they are in front of a heater; with the cold heat transfer medium if they are in front of you. Lying cooler with the warm heat transfer medium being fed. The amounts of heat transfer medium emerging from them are used to heat the gas higher or to cool it lower in the next stage or in the next cycle.

Since the temperature in the cylinder is not even, but the highest or lowest is directly on the piston, it may be appropriate to only feed this part to the next stage and again the part that entered the cylinder last, which leaves it again first to work in the same stage. As can be seen in the design (Fig. 4a and 4b), in addition to the non-return valves 16, additional control elements are required. These are necessary to change the path of the mixture when the piston is in the correct position. From the displacement 29a, the gas flows through the heater 3 0 into the space 3 1 d, in which it assumes temperatures which are above T =. The particles that entered first experienced the greatest increase in temperature, those that came last did not experience any. When the piston retreats, these are fed through the three-way valve 32 into the displacement 31 b (Fig. 4a) until the hotter mixture emerges from the cylinder. At this moment the taps are adjusted as shown in Fig. 4b. The hot gas, which now leaves 31 a, flows into the next stage after 31 b '. Thus, in 31 b no negative pressure is formed, the cock 33 is adjusted so that from the point of use be unused gas having approximately the temperature T2 at the same time with flowing 32nd From the cylinder chamber 3 1 b, after the piston has reversed, the gas is conveyed through the cooler 34 to 29 b, where it assumes temperatures below T1, here the lowest at the piston and the highest at the inlet or outlet, namely T1. When the piston retreats, this part is pushed back to the starting point 29a in this stage, while the part on the piston with the lowered temperature is transferred to the next stage in the space 29a. This second stage works exactly like the first, only the temperature differences are greater. Instead of the mixture that is sucked in in the first stage as a replacement for that which has been dispensed from the point of use, the mixture supplied by the first stage is used in the second stage. One switches so many stages one after the other until the desired temperatures are reached in the released parts of the mixture of the last stage. These parts are then fed to the point of use, from where they are used again, as mentioned, fed back to the first stage.

So that the temperatures in the displacement really remain stratified and are not balanced by vortices, special means will be used, to be discussed below.

The following are some not unimportant suggestions for the Structural design of the device required to carry out the new process compiled. So that the friction of the pistons and piston rods, alone one Requires effort, is reduced as possible, one can conclude the two Cylinder sides against each other by a liquid and the piston guide your rod between the solid walls with little play in the cylinder: Man must bend the cylinder to the [) tube, as shown in Fig. 5 a and 5 b is. Then the piston is best swiveled in an arc around a pivot point.

In order to avoid heat loss of the mixture as much as possible, one will not only insulate the mixture spaces, but also make the walls from one material, which accepts the heat poorly, i.e. with a low heat transfer coefficient. On the liquid level one will put floats 35, which are insulated on their surface against heat.

However, special facilities must still be made to enable it make it possible to always have the same amount of liquid on both sides of the piston to hold if in the two cubic capacities -the pressure is not always the same or does not equalize, at least during a double stroke. Despite. the narrowness of With the constant repetition, the water will split more and more to one side move, if not the way back through a non-return valve 36 in Fig. 6b is released. In order to be able to regulate the amount of water passing through this, there is a need there is still the slide 36 ', which can be adjusted from the outside (Fig. 6a and 6b). A prerequisite for this, however, is that the oscillating piston is either a longer one The liquid column has oscillation time to overtake the piston searches, or vice versa, depending on the circumstances. This is explained in more detail below executed.

A design without a fixed piston as shown in Fig. 7 is also conceivable. The impetus to maintain. the vibration then emanates from a jet nozzle 37, which comes into operation at the appropriate moment. The hydraulic fluid can can be fed to the nozzle from a pressure or elevated tank. The strength of the nozzle effect can be regulated by the height of the float.

From the foregoing it can already be seen that the application of these types of construction to the in Figs. I to q. The circuits shown require special consideration. It is best suited for the circuit according to Fig. 2. The displacements 2oca and 2i a are accommodated at the ends of a U-shaped cylinder. A second is used to accommodate rooms 2o b and 2i b (see Fig. 8). The used gas comes through line 38 from the point of use and flows through the open tap 39 into space 21b. This gives the water flask the opportunity to move towards the space 2o b and to force the mixture contained therein through the open cock 26 (corresponding to FIG. 2) to the line 40. In this it passes through the cooler to the space corresponding to the displacement 20 a in Fig. 2. If the water flask has completely filled the space 2o b and completely released .21 b for the used gas, the taps 26 and 39 are closed at the same time as the normal cycle between 2o a and Zia begins again. The water flask in Fig. 8 now remains at a standstill in 2o b until exhausted gas arrives again. This time the taps 39 'and 26' are opened and the water piston swings in reverse from 2o b to 2 1 b.

When using the mechanical piston and liquid seal type according to Fig: 5 and 6 on the circuits according to Fig. i, 3 and .4 already occurs above mentioned difficulty that the pressures on both sides of the water flask are not are always the same. This can be done using the non-return valve 36 in Fig. 6 can be remedied in their unfavorable effect. The first stage of Fig. I z. B. would then have to be carried out as shown in Fig. 9. The cubic capacities etc. carry the same Designation as in Fig, i.

The check valve can only fulfill its purpose if the oscillation times of the piston and the liquid mass are correctly selected. Should be liquid step through the flap against the direction of movement of the piston, so his The oscillation time should be shorter than that of the liquid mass, but longer if the liquid should pass through the flap in the direction of the piston movement, this so to a certain extent must overtake the piston. Of course, the flap must then too open on different sides. The pressure is equal during opening of the flap on both sides of the cylinder. Can -balance through overpressure take place on one side of the cylinder, as in the circuit according to Fig. 4, so two act Circumstances affect the passage of the liquid. In the case of the one shown in Fig. 9 Execution of the circuit according to Fig. I, the piston would have to be shorter between 3 a and 3 b The period of oscillation is longer than that of the liquid, whereas the one between 4.a and: Ib is longer.

Without the non-return valve, all circuits can do if two complete systems are coupled with one another by means of the water flask, as in Fig.io is shown. Each of the two displacements on either side of the water piston serves the same purpose. The pressures are not the same every moment off, but with a double hul). This is the guarantee given, that as much water as with the one stroke through the cracks in one direction flows back through the next stroke.

A complete pressure equalization can be achieved at any point in time in that one also simultaneously with the connection of the gas-filled displacements establishes the connection of the associated fluid spaces. Fig. I i shows this Execution for the first stage of the circuit according to Fig. I. The names are partly those of Fig. i and 7. Switching is supposed to be done by louvre flaps, for example can be achieved with rubber seal, of which those designated 41 inevitably must be controlled, while those designated by 42 by the liquid flow be automatically transferred. They only serve to avoid water eddies in the temporarily dead rooms. On the scheme according to ebb. .4 can be this type do not apply, because the one switchover in the middle of the oscillation water hammer and Would result in shock losses.

In order to avoid mixing of the colder with the warmer mixture within the cubic capacity with this circuit, since these parts are to be used separately, a special device is necessary, as mentioned above. This is shown in Figs. 12a, i 2 b and i 2 c. At the moment when that mixture enters the cubic capacities 3 i a., 31 a ... and 29 b, 29 b '-; n in Figs. 4 a and 4 b, which is not intended for the next stage, one on the Float fastened rod 43, the thin disc 44, which does not seal on the cylinder jacket, is carried along by the pawl 45 provided with a detent. This is pressed out of the pipe rod by a spring. When the disc comes to the upper cylinder cover, the roller 46 attached to the pawl is depressed through the wall of the guide tube of the rod, and so is the pawl. The disk 44 is thus released. So that it does not fall down again, it has just been pulled over the spring force pushed out locking mechanism 47, by which it is held at the top of the cover until the pawl 45 on its way back grabs it again and takes it down over the locking mechanism. The disk 44 and the float 35 are prevented from rotating by the guide rod .4ä.

It is not always necessary to have the heat exchangers in separate rooms for mixture and heat transfer medium, but it is also possible to have this in the mixture inject. However, this version is only appropriate if either the substance used for evaporation is worthless, so that it is lost with the heat transfer medium can, or it is insoluble in the heat transfer medium, so that it can be recovered from it can.

To get off the increased with the help of the devices described above Heat gradient to gain strength, one passes the mixture with the highest temperature, that contains a corresponding amount of vapor from the injected liquid into a Gas steam engine and lets it do its work in it. From there it flows relaxed in cfen from the cold heat transfer medium or frozen mixture at a low temperature held condenser, where most of the steam is condensed. from there, gas and liquid are brought back to the upper pressure by a pump and start their cycle all over again.

Claims (7)

PATENT CLAIMS: i. Process for utilizing small temperature gradients, z. B. the gradient between different temperatures at different depths tropical waters, characterized in that one with the temperature of the cold Heat transfer medium entering gas in a constant space by passing it heated to the warm heat carrier and that a liquid during the heating of the gas is injected between the temperature limits in question has the greatest possible difference in vapor tension, in the later course of the stroke and is precipitated again during cooling. 2. Procedure according to claim i, characterized in that helium or another (monatomic) Gas with high x and high specific heat is used. 3. The method according to claim i and 2, characterized in that it is carried out in several stages, in in such a way that the temperature increase (decrease) of the achieved in each stage Mixture of gas and steam in your heater (cooler) of the next stage on theirs Mixture is transferred. . 4. The method according to claim i and 2, characterized in that that it is carried out repeatedly in a single step, until the desired (high or low) final temperature is reached. Procedure according to Claim i and 2, characterized in that it is in. Several stages in the manner is carried out that the heated in the first stage (chilled) Mixture is fed through a cooler (heater) to the next stage, whereupon in this it again wanders through the heater (cooler) and then through a cooler (Warmer) goes to the third stage and so on until the desired final temperature is reached. 6. The method according to claim 5, characterized in that only the hottest (coldest) parts of the entire mixture passed on to the next stage are, while the parts that little the originally given temperature limits exceed (fall below), immediately subjected to the same process again will. 7. The method according to claim z, 2, 3, 4, 5 or 6, characterized in that that the one coming out of the cooler (heater) and heated there (cooled) is colder (Warmer) heat transfer medium for preheating (pre-cooling of the Mixture is used. B. The method according to claim z, 2, 3, 4, 5 or 6, characterized characterized in that one strongly cooled (heated) mixture amounts before the passage through the heater (cooler) in a special heat exchanger with the cold one brings together (warm) heat transfer media and the cold (heat) extracted from them in in the next stage or in the next cycle. G. contraption for applying the method described above, characterized in that the cylinders are designed as U-shaped tubes, in the lower arc of which the piston swings back and forth, and that the seal between this and the cylinder wall is achieved by an oscillating column of liquid. 1o. Apparatus according to claim g, characterized in that the rigid piston is omitted and vibrates through the displaced liquid is formed. II. Device according to claim g and 1o, characterized characterized in that the U-shaped tube is forked and means at the fork point are arranged to divert the gas and the liquid forming the piston.