DE2330216A1 - Heat pump system in power plant - solution compound mixed at low level gives up heat during separation - Google Patents

Abstract

The solution components for absorbing heat at a low temperature exhibit a negative enthalpy, i.e. feature a negative dilution heat and give up heat at a higher temperature when the components of the solution are separated. The system comprises a mixing chamber, separator and heat exchangers with flow control by pumps. The solutions may be made up of nitrates, halides, chromates and/or thiosulphates. Separation may be achieved by evaporation, crystallization, extraction, adsorption or ion exchange.

Description

II.-U. H Ö Π ίϊ E '6078 Neu Isenburg

At Porsthaua Gravenbruch 17

PROCEDURE FOR PUMPING ViBH

The invention relates to a method for "pumping ¹ *, ie for transporting heat from a lower to a higher level. It can be used economically within wide temperature limits, especially above normal ambient temperature, and thus expands the industrial process scale into the warm area." »·

The invention is characterized in that solution components which have a negative enthalpy of solution (ie negative "dissolution" or "dilution ^{heat 11} )" are added to the mixture for the purpose of absorbing heat at a lower temperature, and the solutions are broken down again into the components at higher temperatures for the purpose of dissipating heat.

The transport media of absorbed heat are in the case of the invention Processes so solutions or. Liquids, in contrast to the currently doainierend processes, in which there are gases. Through this the method according to the invention has the physical-technical basis for coping with current economics Tasks, such as the return transport of waste heat from power plants Level of work. - -

Suitable solution components which can be used in the context of the invention are, on the one hand, salts and / or other compounds which are in Dissolve water and / or other solvents while removing heat and on the other hand those concentrated solutions which are characterized by a negative heat of dilution, that is, when diluted (or if there are, among other things, solutions of various connections

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corresponding property, when mixing) cool down.

Salts, inorganic and organic compounds, solvents and solutions that meet the requirements are known from the literature and can also be combined in new ways depending on the requirements, especially if they are less common media, such as inorganic water-like solvents, acts. Some of the known solution combinations have long been used in the scientific experimental technique for the production of so-called "cold mixtures ¹¹ or" cold solutions ", primarily solutions of various nitrates (such as NH EO ₅ , N? NO) halides (such as NH Cl, IiJ, CaCl _3. 6 H ₀ O), icetates (such as NaCgH ₃ O _2. 3 H ₂ O), chromates (such as (Kn ^) ₂ Qr ₂ O ₇ ) and / or thiosulfates (such as Ka ₂ S ₀ O ₅ . 5 H ₃ O) - alone or in a mixture - in water and / or polar organic solvents, of solid C0 _o in liquid S0 _? And others more.

All methods can be used to separate the solution components which are common for such tasks, for the decomposition of saline Solutions, for example those suitable for desalination of seawater, such as separation by phase change (evaporation, Crystallization, gas hydrate formation, precipitation, extraction, adsorption, ion exchange, phase disintegration in the critical area etc.), temperature and concentration gradients (thermal diffusion, membrane diffusion, etc.) electromagnetic fields (electrodialysis, magnetic Effects etc.) mass acceleration (separation nozzles, ultracentrifuges etc.) or other effects.

The heat transport system corresponding to the invention is the process principle correspondingly simple:

As shown schematically and by way of example in Figure 1, it consists essentially of the mixing chamber (1), the separating device (2) and the heat exchangers (3) and (4) »in which the heat exchange between the solution components supplied to the mixing chamber and of the solution leaving it.

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The solution components that combine with each other while cooling are separated from the mixing chamber (i) by the lines (22) and (2j) by means of punches (5) and (6), e.g. the aqueous slurry a salt such as ammonium nitrate or calcium chloride hydrate through line (22) and water as a solvent through line (23).

In the mixing chamber (i) the combined solution components form one so-called "cold solution" produced by a medium in the mixing chamber (i) arranged heat exchanger (11) flows through, absorbs heat.

Warmed up, but still colder than the solution components, leaves the solution enters the mixing chamber (i) through line (21) and is in the Heat exchangers (3) and (4) in countercurrent to the solution components (which cool down in the process).

In the separating device (2), the warm solution is broken down into its components disassembled and the crystallization or concentration heat that may be released through the heat exchanger (12) (which, for the sake of simplicity, is only drawn in the separating device (2)). By the way, comes the heat absorbed by the solution in the course of the between solution and Solution components taking place heat exchange for release. Ba of course, as a rule, the sum of the heat capacities of the solution components is greater than the heat capacity of the solution in the entire range between solution temperature and separation temperature remove the heat not required by the components to warm up the solution »

For the heat exchange between the solution components and the solution, a temperature difference of 8-10 C is usually sufficient. This temperature difference is also sufficient for the most common separation processes, such as multi-stage flash evaporation or the extraction process to separate the solutions into their components. If one disregards possible special constructions, the cooling capacity of the "cooling solution" must be sufficient both to compensate for the temperatures ff c-rena and to absorb additional heat.

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For example, a solution of 1,000 g of ammonium nitrate in 1 liter of water absorbs 45 kcal of heat at 12 C. Of this, approx. 10 kcal can be available for the compensation of the temperature gradient necessary for heat exchange and approx. 35 kcal for the actual heat transport.

Application example ,

In the steam power process, through which, among other things, the predominant Amount by which electrical energy is obtained about $ 40 of the heat brought in converted into work and about 60 $ ^ dissipated in cooling water or cooling air.

Using the invention, it is possible to remove the Heat of condensation of the low-pressure steam («waste heat] to the temperatures required to generate high-pressure steam to "pump".

The heat transport system that can be used for this is shown in Figure 2 as an example and shown schematically. In its basic features it is similar to that shown in Figure 1, which is why the apparatuses and pipelines that have the same task as there are identified by the same number.

The condensation heat of the low-pressure bowl (HD), which occurs at approx. 100 C, is transferred in the mixing chamber (i) through the heat exchanger (11) to a cold solution (= solution), which is created by dissolving potassium iodide in water. In the separating device (2) designed as a cyclone, the solution is then broken down into its components, an aqueous potassium iodide sludge and water (or water vapor). In the heat exchangers (5) and (4), as described, the heat exchange takes place between the solution (flowing through line 21) and its components (ie that through line ? 2

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"moving potassium iodide sludge and that flowing through line 23 Water "or the one present in the hottest section of the line 23 Steam).

The decomposition of the solution into water (or water vapor) and aqueous Potassium iodide sludge occurs through phase breakdown in critical Area of solution. For economic reasons, the working pressure in the entire system is close to the critical pressure of the solution, i.e. at about 235 ata. The solution pump (7) (which is provided here as an example instead of the pumps (5) and (6) listed in Figure 1 is) therefore only functions as a rolling device, i.e. for the circulation of the heat transfer solution or Solution components.

The temperature range is set by means of the heat exchangers (3) and (4) between the solution temperature in the mixing chamber (1) and the critical one Temperature of the solution in the cyclone (2), i.e. between about 100 and 43O C, bridged. For the manufacture of the heat exchange The necessary temperature gradient is provided by the (e.g. oil-heated) top heater (δ) and the (e.g., cooled water) final cooler (9) and (1O).

The heat in the mixing chamber (i) at around 100 C for condensation of low pressure steam by means of the heat exchanger (11) reaches the absorption, is partly in the heat exchanger or evaporator (12) at about 230 C to the condensate for the development of Released high pressure steam, from a partial flow of the line (23) water vapor or water flowing through.

The condensate evaporating in the heat exchanger (12) brings the in

the condensate line (24) arranged condensate pack (13) of the

in (11) herachenüen condensation pressure (approx.1.27 ata) on the in (12) required vaporization pressure (approx. 20 ata).

For condensation of 1/2/2 kg Nif.'üox'ilruckd & iiipf at approx. 105 C (in 11) and Uiodex'voi'dauijpfuns of the Kundonsat with the production of

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High pressure steam at approx. 2JiO C (in 12) 100 kg solution (- 54 »3 liters at 4 ° C), consisting of 32.47 kg water and 67.53 kg potassium iodide, are to be circulated once in the heat transport system.

When it is formed from the components (H ₉ O and KI) at 100 C and approx. 235 ata pressure, the solution absorbs approx. 763.5 kcal V / arm, which is entered through condensation of the 1426 kg of low-pressure steam (at 105 C) .

In addition, the solution in the tip heater (ε) at approx. 430 G 38I.5 kcal supplied, partly to support the generation of high-pressure steam (in 12) and partly to produce the temperature gradient necessary for the heat exchange.

For heating the condensate from IO5 C to 230 C and its evaporation there the system delivers 801.5 kcal. The residual heat, 343 * 5 kcal, is discharged to cooling water.

Of a total of 1145 kcal of heat introduced (763 5 kcal at 10 5 C, 38I.5 kcal at 430 C) can therefore give the system 801.5 kcal (at 23O C) groove heat can be removed, which is a thermal efficiency of 70 / ^.

The amount of solution to be pumped through the system per kg of steam condensate with 38 liters is in the order of magnitude of the conventional one Steam power operation the amount of cooling water to be used (approx. 36 liters / kg condensate) or similar The pump (7) required for circulating the solution is (in addition to the condensate pump 13 which has also been required up to now) the only moving apparatus in the system.

The main effort falls on the devices for the Heat exchange, primarily between the solution and its components.

If, as exemplified by tocchricton, the l / är ^ causta-ucch auRHchlivi'l indirectly νυιγ; οΐίοη:; ιηη, nrp ^ e ^ uii you for the- V / i ', rir.e exchangers (3) vai (4) large auntaufjchflachen that vcgsn de? at the same pressure

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However, the solution and solution components can be made very thin and simple (as sheet metal plates, sheet metal spirals, etc.), especially since it is possible to examine the chemical nature of the Lö-Bungnn to match the requirements of the heat exchanger materials.

The heat exchangers (3) and (4) can also be wholly or partly be replaced by other devices serving for heat exchange, such as those in which the heat is replaced by pesticides, pressurized gases and / or thermally .stable auxiliary fluids is transferred. With In the latter, the heat is transported e.g. through evaporation and condensation or (if the auxiliary bites are in the solution and their components not noticeably loose) by countercurrent flow in turbulent columns or similar contact devices Also carry out direct water vapor transfer, ion diffusion Membranes and many other methods of heat transfer.

I.

The potassium iodide can also be used as dust or powder instead of as sludge be transported, e.g. with the help of gas streams (via corresponding Separation systems such as cyclones and the like) and finally, as described above, instead of potassium iodide; Mixtures of the same with other compounds or other salts or substances occur, such as eutectic mixture '?, which are present as melts in the entire conveying area, as well as auxiliary substances which, for example, affect the sludge properties improve, etc.

The effort to integrate the heat transport system in a steam power plant are significant Distribute gegenübor: So the fuel requirement and the Kühlvusoorverbrauch decline compared to conventional works the same performance significantly. Associated with this is savings for systems that are otherwise required for the use or provision of operating resources, such as fuel bunkers, heating systems, reactors, cooling water preparation facilities and the like.

Finally, you win there by using the Wiirmotran3portayotGins

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also the pollution of the environment through harmful effects of the steam power plant, such as the thermal load on bodies of water, the pollution of the atmosphere by dust, emissions, etc.

Organic combination of different 'variants of the invention alone or those with conventional heat transport systems enable bridging significant temperature ranges. Vie with the previously known Systems for pumping heat is also in accordance with the invention at the higher temperature level, both at the lower The heat absorbed by the temperature as well as that of the transport expenditure iiq ^ uivälonte released. Since the latter is relatively low, this can according to the invention Process not only for solving refrigeration tasks, such as for cooling trees, gases and liquids, but (as shown in the detailed example) also for Energy generation from industrial heat sources (such as exhaust steam, hot synthesis gas streams) and natural heat reservoirs (such as rivers, Ocean currents and atmospheric air).

This means that the invention can be used in a variety of technical ways Design as axich for a wide variety of heat transport tasks apply.

Claims (2)

Patent claims 1.) Method of transporting heat from lower to higher-ο High level, characterized in that for the purpose of heat absorption it would take low temperature solution components get into the mixture, the one negative enthalpy of solution (i.e. negative "Löimiign-" or "Verdünnungswäi-me") and the solutions for the purpose Heat dissipation or heat dissipation at a higher temperature again in the LöDungßkouiponenton are decomposed. 2 c Verf.'ilireij according to claim 1, thereby gehonm-c-ichm-t, 'let as Lcr; anr;:; l: .oi ._; n - ;: ontr.n .'Je ¹ : uo and / od-r aii'ierc Vcro: i iii'un ^ xji oiiij ',: ^ - Ii; ü 409881/0679 _p " SAD ORtOtNAL that dissolve in water and / or other solvents with removal of heat and / or such concentrated solutions, which are characterized by a negative heat of dilution, So when diluting (e.g. if there are solutions of different Compounds of the same property act, when mixing) cool down. Method according to claim 1 and 2, characterized in that for Separation of the solution components mainly methods are used that are common for such tasks, for the decomposition Saline solutions, for example, those suitable for desalination of seawater, such as separation by phase change (Evaporation, crystallization, gas hydrate formation, precipitation, extraction, Adsorption, ion exchange, phase decay in the critical area etc.), temperature and concentration gradients (thermal diffusion, Membrane diffusion etc.) electromagnetic fields (electrodialysis, magnetic effects etc.) mass acceleration (Separation nozzles, ultracentrifuges etc.) or other effects. Method according to Claims 1 to 3, characterized in that the heat between the solution components and the completely or partially formed solutions (e.g. in heat exchangers or with the help of heat-transferring media such as gases, liquids and / or solids) and / or the temperatures of the Partner through (or within the scope of) changes in the concentration of dissolved substances (e.g. through direct vapor transfer or with the help of of membranes) can be changed in opposite directions. Method according to Claims 1 to 4, characterized in that the Solution components at or near the critical pressure the solutions mixed or combined w / earth and the separation of the resulting solution into its components Raising the temperature from the miscibility or heat absorption temperature on (roughly) the critical temperature of the Lörmni.en, i.e. in (bavf. nohe von) their critical area wJ approx. BATH 409881/0679