DE102010043851A1 - High-temperature heat transport apparatus for transferring heat from heat source to heat sink, has transport fluid introduction device connected with pipe section of ring line, such that constant diameter over entire length is set suitably - Google Patents

Abstract

The apparatus (10) has a ring line (12) in which the heat source and heat sink are arranged. The ring line has feed line and return line for encompassing the heat sink. The sink has reaction chamber to convert heat from heat-transfer fluid. A bubble pump has device for introducing fluid into heat transport fluid, and separation device for separating gaseous transport fluid from heat-transfer fluid comprises. A device for introducing transport fluid is connected with pipe section of ring line, such that a constant diameter over entire length of device is set suitable for forming slug flow.

Description

The present invention relates to a high-temperature heat transport device according to the preamble of claim 1.

Many physico-chemical processes require the supply of heat at a high temperature level to produce and maintain operating temperatures of 800 ° C and above during a predetermined operation. For this purpose, it is known, for example, (a) to directly fire the reactors in which these processes take place, (b) to heat the reactor by circulating heat transfer material, or (c) to charge the reactor indirectly, e.g. Heat pipes, for example, heat to the desired temperature, from (a) to (c) the distance between the heat source and the heat sink (the place where the process is performed) and thus the Directness of heat transfer decreases. This fact is reflected in the possibilities of heat transfer and the problems of their technical realization, for. B. in more extensive piping systems, which must be isolated accordingly.

From the DE 39 07 767 A1 For example, there is known a "heat exchanger for high temperature applications", particularly for hot gas engines, stirling engines, steam generators or the like, which comprises a vessel containing liquid metal as a heat carrier which increases the heat flow of an external heating source through which it is heated a heat sink transmits. Here, the heat sink is largely surrounded by the liquid metal. A similar principle is also in the DE-AS 16 01 462 described.

In the DE 39 07 767 A1 the circulation process of the liquid metal necessary for heat transport is effected by continuous or intermittent "introduction" of inert gas into the liquid metal, whereby the inert gas bubbles forming in the liquid metal are made responsible for the said circulating effect. The heat transfer can be accelerated by "pumping" the inert gas in the circuit. This choice of words in the DE 39 07 767 A1 suggests that the heat transfer without "pumped" may be insufficient.

A high-temperature heat transport device according to the preamble of claim 1 of the present invention is known from WO 2010/057919 A1 the same applicant.

It is an object of the present invention to propose a high-temperature heat transport cycle, which - starting from the WO 2010/057919 A1 - allows more efficient and thus more economical heat transport at high temperature level.

This object is solved by the features of claim 1. Advantageous embodiments are defined in the subclaims.

According to the present invention (claim 1) is a high-temperature heat transport device for transporting heat from a heat source to a heat sink by means of in a loop, in which the heat source and the heat sink are arranged, circulating heat transfer fluid, wherein (a) the loop one And (b) the heat sink comprises a reaction chamber in which at least one educt is converted into at least one product by the heat supplied via the heat transfer fluid, characterized by a bubble pump for maintaining the circulation of the heat transfer fluid, the one Device for introducing a transport fluid into the heat transfer fluid and a separation device for separating the transport fluid from the heat transfer fluid, and in that (d) the device for introducing a transport fluid (hereinafter "E called "inleitungsvorrichtung") is connected to a pipe section of the loop, which has a constant diameter over its entire length and is designed so that it is suitable for the formation of a slug flow (English: "slug flow"). The pumping action of a bubble pump is based on a density difference between a liquid, here the heat transport liquid, and a fluid forming therein and bubbles, here the transport fluid, the bubbles undergo a buoyancy due to the density difference, thereby "entrain" the surrounding heat transfer fluid. Or, to sum up, a liquid with bubbles has a lower density than a liquid without bubbles. That is, the pumping action of the bubbles formed in the liquid is gravitationally induced and therefore does not involve any mechanical parts. In particular, energy is needed only to introduce the transport fluid and not to move the heat transfer fluid. According to the invention, the bubbles are introduced into the heat transfer fluid through the introduction device and, after covering a predetermined distance within the loop, are removed from or removed from it by the separation device. If one tries to explain a chemical mechanism, one could say that the bubbles act as a catalyst, causing a reaction, in this case the transport of the heat transfer fluid, while remaining unchanged. According to the above feature (d), the pipe section has a diameter "designed to be suitable for forming a surge flow". Like it for example in "A Review of Bubble Pump Technologies", Benhmidene et al., Journal of Applied Sciences 10 (16): 1806-1813, 2010 and the literature cited therein, four flow modes can be distinguished in a two-phase flow induced in a tube, which differ among other things with respect to their transport efficiency, which is highest in the presence of a surge flow. The surge flow differs, for example, from the so-called plug flow as another flow mode in that the bubble diameter is smaller than the inner diameter of the tube so that a liquid film is obtained between each bubble and the inner surface of the tube remains. However, the individual flow modes only occur when the inner diameter of the tube is "of the order of magnitude" of the bubble diameter, ie both diameters are "approximately" the same. In particular, they do not adjust if the inner diameter of the tube is significantly larger than the bubble diameter. The claim wording according to which "a diameter is designed so that it is suitable for the formation of a surge flow" means according to the invention no restriction to the flow mode surge flow. Rather, this is to be understood as an implicit definition of the spatial relationship between the inner diameter of the tube and the bubble diameter, wherein the term "wave flow" also by the other four flow modes, for. B. the "plug flow" could be replaced. The suitability for the formation of such a flow is not present, for example, when the tube is replaced by a vessel with a very large compared to the bubble diameter inner diameter. It should be noted that the high-temperature heat transport device according to the invention according to the wording of claim 1 is not only suitable for heating, but also for cooling. Further, the flow is defined according to the invention as running from the heat source to the heat sink, the return in the reverse direction.

According to an advantageous embodiment of the present invention (claim 2), the pipe section is arranged either in the flow line or in the return line. Furthermore, according to a further advantageous embodiment of the present invention (claim 3), the separation device also either in the flow line. or the return line arranged. The two components of the bladder pump, the introduction device and the separation device, can thus be arranged distributed in any combinable manner either only in the flow line, only in the return line, or on both lines thanks to the ring line. However, it is advantageous, in particular if a gas is used as the transport fluid, to introduce it in the flow direction behind the heat source, because there form larger bubbles due to the higher temperature of the heat transfer fluid under otherwise identical conditions than in the laxative of the heat sink line (return line). How the conditions are to be set in individual cases and which parameters must be taken into account has been determined theoretically and experimentally in the past (cf. "A Review of Bubble Pump Technologies", Benhmidene et al., Journal of Applied Sciences 10 (16): 1806-1813, 2010 , and the literature cited therein). In contrast to the z. B. from the DE 39 07 767 A1 known approach, where by local heating z. B. solar energy, a gas phase from the liquid heat transfer fluid is generated ("solar driven bubble pump") remains according to the present invention, the phase of the heat transfer fluid in the loop unchanged and coexistent with the phase of the introduced transport fluid. The physico-chemical properties of heat transfer fluid and transport fluid can be matched to one another, taking into account constructive variables such as the diameter of the flow line or return line, in order to obtain optimum transport of the heat transfer fluid (cf., for example, paragraph [0029] of US Pat US 2007/0084207 A1 ).

According to a further advantageous embodiment of the present invention (claim 4), the introduction device is connected to a front in the direction of circulation of the heat transfer fluid end portion of the pipe section. The introduction of the transport fluid at this position - regardless of whether the introduction takes place in the flow line or the return line - increases the pumping action, which is also increased with increasing length of the preferably vertically disposed tube, moreover.

According to a further advantageous embodiment of the present invention (claim 5), the high-temperature heat transfer circuit comprises a control loop in which an output of the heat sink is a controlled variable and a dosage of the transport fluid amount and / or a flow rate of the heat transfer fluid is a control variable. The heat sink is the place where the conversion of the at least one reactant into the at least one product takes place. The transformation is one or a plurality of chemical / biological reactions that can be described by reaction equations. Starting materials for the purposes of the present invention are the products formed in these reactions, which can be detected individually or in their composition (claim 11). Since the equilibrium of the reactions is temperature dependent, the temperature in the heat sink, in turn, depends on the configuration of the high temperature heat transfer device The measurement of one or more substances involved in the reactions may be used to regulate the parameters of initiation (amount, rate of introduction, pressure, etc.) of the transport fluid, thus shifting the chemical balance and increasing the product gas quantity and quality regulate.

According to a further advantageous embodiment of the present invention (claim 6), the heat transfer fluid is tin, galstan or lithium beryllium fluoride (FLiBe). The great advantage of these materials is that unlike alkali metals they are non-toxic, non-explosive and non-combustible. The latter, a salt consisting of a mixture of lithium fluoride (LiF) and beryllium fluoride (BeF 2), is used in particular in the highly sensitive environment of nuclear research reactors as circulating medium in high-temperature heating circuits (cf., for example, the "holten-Salt Reactor Experiment" (cf. MSRE) at Oak Ridge National Labaratory).

According to a further advantageous embodiment of the present invention (claim 7) transport fluid is a noble gas, air, water or water vapor. The advantages of these substances are, in particular, that they are cheap. Water also has the advantage that it is already in a liquid state, so it is not necessary as under certain circumstances for a gas, with high energy and therefore financial expense to condense (liquefy) must. Water vapor is already present in the HPR process at a sufficient overpressure and does not have to be purchased or additionally produced.

According to further advantageous embodiments of the present invention, which can be used individually or in combination, the heat sink comprises a reformer for producing combustible product gas from carbonaceous feedstocks by allothermic steam gasification (claim 8), the heat source comprises a combustion chamber for combustion of carbonaceous feedstocks and / or pyrolysis residues of the reformer comprises (claim 9) and the deposition device is used for the deposition of diffused in the heat sink in the heat transfer fluid hydrogen (claim 13). Preferably, in the reformer and / or the combustion chamber, a fluidized bed is formed, and the loop is formed within the reformer and / or the combustion chamber as a tube bundle or pipe loop design. This variant is in the WO 2010/057919 A1 The same applicant described in detail, and their operation is described below with reference to 3 ( 1 of the WO 2010/057919 A1 ) summarized. 3 shows the basic structure of a high-temperature heat transport device, the heat sink in the form of a reformer 2 and an external heat source in the form of a combustion chamber 4 includes. The reformer 2 includes a feeder 8th for fuel, a water or steam supply 10 and a product gas discharge 12 , At a temperature of 800 ° C to 900 ° C product gas is produced by allothermic steam gasification of carbonaceous fuels. The reformer 2 and the combustion chamber 4 are over a loop heat pipe 14 connected to a heat transport device.

The loop heat pipe 14 includes a heat receiving side 16 and a heat-emitting side 18 passing through a steam line 20 for vaporous heat transfer medium and a liquid line 22 are connected to each other for liquid heat transfer medium. About a lock 24 that the reformer 2 with the combustion chamber 4 connects, pyrolysis residues from the reformer 2 the combustion chamber 4 supplied as fuel. Into the fluid line 22 is between carburetor 2 and combustion chamber 4 a hydrogen separation device 30 arranged. By combustion of the pyrolysis residues from the reformer 2 and / or by combustion of additional fuel is in the combustion chamber 4 Heat generated by the heat-absorbing side 16 of the loop heat pipe 14 is taken, which via the liquid line 22 supplied liquid heat transfer medium evaporated. The vaporous heat transfer medium flows over the steam line 20 in the reformer 2 , condenses on the heat-emitting side 18 of the loop heat pipe 14 and thereby provides the high temperature heat necessary for allothermal steam gasification. In operation, it turns out that hydrogen is generated by the jacket of the loop heat pipe, which is usually made of metal 14 inside the loop heat pipe 14 diffuses and settles in the area of the heat-emitting side 18 collects. There he forms a hydrogen pad, which prevents heat transfer or at least greatly reduces, so that through the loop heat pipe 14 transferred heat output reduced. This phenomenon is known. One way to meet him is to loop the heat pipe 14 or, more generally, to coat the "heat transfer tube". Another approach will be in the DE 102006016005 A1 followed, whereby the pressure prevailing in the interior of the heat transfer tube pressure is increased (disadvantage: difficult technical handling) and Spülkappen be provided (disadvantage: process of Ausdiffusion weak). According to the WO 2010/057919 A1 becomes the liquefied heat transfer medium via the liquid line 22 together with in the reformer 2 formed and in the heat transfer circuit 14 diffused hydrogen of the hydrogen separation device 30 fed. Through the hydrogen separation device 30 be the hydrogen and other impurities of the separated liquid heat transfer medium, and the remaining liquid heat transfer medium is returned to the combustion chamber 4 supplied, so that the heat carrier circuit is closed. The fundamental difference of the present invention is that the high-temperature heat transport device according to the invention comprises a bubble pump, by means of which the two-phase system (two-phase flow) described above is produced in the loop from two different materials.

According to a further advantageous embodiment of the present invention (claim 14), the separated transport fluid is returned to the bladder pump. That is, according to this advantageous embodiment, there are two circuits, a heat transfer fluid circuit and a transport fluid circuit, which overlap or interlock with each other, that is, they are interlocked. H. have a part of the loop together.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings are:

1A and 1B schematic representations of two variants of a high-temperature heat transfer circuit according to a first preferred embodiment of the present invention;

2A and 2 B schematic representations of two variants of a high-temperature heat transfer circuit according to a second preferred embodiment of the present invention;

3 a schematic representation of a high-temperature heat transport circuit according to the prior art.

The in the 1A and 1B schematically illustrated variants of a high-temperature heat transfer device 10 according to a first preferred embodiment of the present invention differ from the in 3 in particular, by the physical mechanism by which a fluid - consisting of a heat transfer fluid and the transport fluid therein in bubble form, or in other words: the transport fluid in bubble form and the heat transfer fluid conveyed by the same - is shown in FIG a ring line 12 circulated and held in its orbiting motion. This mechanism consists in the buoyancy that the transport fluid undergoes due to its lower density in the heat transfer fluid compared to the heat transfer fluid, and in the best possible transmission of this movement to the heat transfer fluid by appropriate dimensions and operating conditions.

In particular, the high-temperature heat transport device comprises 10 of the 1A a heat source 2 in the form of a combustion chamber 14 , a heat sink 16 in the form of a reformer 16 and a bubble pump 18 in the loop 12 arranged and through which they are fluidly and thermally connected to each other. In addition, the reformer 16 over a lock 20 with the combustion chamber 14 connected. The ring line 12 includes a flow line 12-1 from the Bennkammer 14 to the reformer 16 and a return line 12-2 from the reformer 16 to the combustion chamber 14 , Furthermore, the bubble pump includes 18 a separator 22 in the supply line 12-1 is arranged, and an introduction device 24 that are in the return line 12-2 is arranged.

In the 1A Dashed arrows represent those of the combustion chamber 14 or the reformer 16 supplied or discharged by these substances that describe the processes taking place in them. That is, "B1" indicates one of the combustion chamber 14 externally supplied fuel (plus an oxidant such as air), and "B2" designates one of the combustion chambers 14 from the reformer 16 supplied fuel (pyrolysis residues), "R" indicates a combustion of B1, B2 in the combustion chamber 14 generated flue gas, "B" designates one the reformer 16 supplied fuel (plus H ₂ O), and "P" denotes one in the reformer 16 product gas produced by allothermal steam gasification of "B". B, B1 and B2 consist essentially of carbonaceous feedstocks.

In the 1A solid arrows represent the fluid flows of the high-temperature heat transfer device according to the invention 10 , In particular, that of the reformer 16 laxative fluid flow cooled heat transfer fluid + transport fluid + hydrogen (H ₂ ), wherein the hydrogen as described above, in the reformer 16 through the wall of the loop 12 is diffused into the fluid stream. The transport fluid and the hydrogen are in the separator 22 deposited, so that the fluid flow to the separator 22 only consists of the heat transfer fluid whose temperature in the subsequent combustion chamber 14 is increased again. The ones in the combustion chamber 14 heated heat transfer fluid enters the introduction device 24 the bubble chamber 18 where the transport fluid is introduced, which drives the cycle. In the flow direction immediately after the introduction device 24 the fluid flow contains the Heat transfer fluid and with this bubble-shaped moving transport fluid. This completes the cycle.

Equivalent ratios are in the 1B shown variant. The difference to the in 1 variant shown is that both the separation device 22 as well as downstream in the flow direction introduction device 18 in the return line 12-2 the ring line 12 are arranged. Again, however, that the separation device 22 the one in the reformer 16 Hydrogen diffused into the fluid stream as well as through the introduction device 18 - Removed in this variant in the previous run - introduced into the fluid flow transport fluid from the fluid stream.

The in the 2A and 2 B schematically illustrated variants of a high-temperature high-temperature heat transport device 10 According to a second preferred embodiment of the present invention differs from the in the 1A respectively. 1B illustrated variants in that a transport fluid return TFR of the separator 22 to the introduction device 18 returns, so that the separated transport fluid is reused.

Although the present invention has been disclosed in terms of the preferred embodiments in order to facilitate a better understanding thereof, it should be understood that the invention can be embodied in various ways without departing from the scope of the invention. Therefore, the invention should be understood to include all possible embodiments and embodiments to the illustrated embodiments which can be practiced without departing from the scope of the invention as set forth in the appended claims.

LIST OF REFERENCE NUMBERS

10

High-temperature heat transfer device

12

loop

12-1

Supply line from 12

12-2

Return line from 12

14

combustion chamber

16

reformer

18

bubble pump

20

lock

22

separating

24

Introduction device

B, B1, B2

fuels

P

product gas

R

fumes

TFR

Transport fluid return

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 3907767 A1 [0003, 0004, 0004, 0009]
• DE 1601462 [0003]
• WO 2010/057919 A1 [0005, 0006, 0014, 0014, 0015]
• US 2007/0084207 A1 [0009]
• DE 102006016005 A1 [0015]

Cited non-patent literature

• "A Review of Bubble Pump Technologies", Benhmidene et al., Journal of Applied Sciences 10 (16): 1806-1813, 2010 [0008]
• "A Review of Bubble Pump Technologies", Benhmidene et al., Journal of Applied Sciences 10 (16): 1806-1813, 2010 [0009]

Claims (14)

A high-temperature heat transport device for transporting heat from a heat source to a heat sink by means of a circulating in a loop, in which the heat source and the heat sink are arranged heat transport fluid, wherein (a) the loop comprises a flow line and a return line; and (b) the heat sink comprises a reaction chamber in which at least one reactant is converted into at least one product by the heat supplied via the heat transfer fluid. marked by: (C) a bubble pump for maintaining the circulation of the heat transport liquid, comprising a device for introducing a transport fluid into the heat transfer fluid and a separation device for separating the gaseous transport fluid from the heat transfer fluid, and in that (D) the device for introducing a transport fluid is connected to a pipe section of the loop, which has a constant diameter over its entire length and is designed so that it is suitable for the formation of a surge flow. High-temperature heat transport device according to claim 1, characterized in that the pipe section is arranged in the flow line or the return line. High-temperature heat transport device according to claim 1 or 2, characterized in that the separation device is arranged in the flow line or the return line. High-temperature heat transport device according to one of claims 1 to 3, characterized in that the device for introducing the transport fluid into the heat transfer fluid is connected to a front in the direction of circulation of the heat transfer fluid end portion of the pipe section. High-temperature heat transport device according to one of claims 1 to 4, characterized in that it comprises a control loop in which an output of the heat sink is a controlled variable and a dosage of the transport fluid amount and / or a flow rate of the heat transfer fluid is a control variable. High-temperature heat transport device according to one of claims 1 to 5, characterized in that the heat transfer fluid is tin, galstan or lithium beryllium fluoride. High-temperature heat transport device according to one of claims 1 to 6, characterized in that the transport fluid is a noble gas, air, water or water vapor. High-temperature heat transport device according to one of claims 1 to 7, characterized in that the reaction chamber comprises a reformer for producing combustible product gas from carbonaceous feedstocks by allothermic steam gasification. High-temperature heat transport device according to claim 7, characterized in that the heat source comprises a combustion chamber for combustion of carbonaceous feedstocks and / or pyrolysis residues of the reformer. High-temperature heat transport device according to claim 9, characterized in that the combustion chamber is a fluidized bed combustion chamber. High-temperature heat transport device according to one of claims 8 to 10, characterized in that the controlled variable is a composition of the combustible product gas. High-temperature heat transport device according to one of claims 1 to 7, characterized in that the reaction chamber comprises a calciner. High-temperature heat transport device according to one of claims 8 to 12, characterized in that the deposition device is used for the separation of hydrogen diffused in the heat sink in the heat transfer fluid. High-temperature heat transport device according to one of claims 1 to 13, characterized in that the separated transport fluid is returned to the bladder pump.

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