CN85105909A - The thermo-electric generation of direct contact heat exchange process - Google Patents

Abstract

The present invention has announced the thermo-electric generation of a kind of low boiling working fluid and water (comprising seawater, salt solution and the selected aqueous solution, as follows) direct contact heat exchange process, is applicable in ocean thermal energy conversion, salt lake thermo-electric generation and the waste heat thermo-electric generation.

The major technique feature of this method is to select for use water insoluble and low boiling working fluid that proportion is different with water and utilize the hydraulic pressure of seawater own to make seawater enter container for evaporation automatically or CONDENSATE POT is carried out heat exchange, and increases and reclaim remaining working medium device and reclaim micro-working medium.

This method can be saved heat exchange equipment, and then can improve heat-transfer effect and generated output, saves investment and reduces volume etc.

Description

The thermo-electric generation of direct contact heat exchange process

The present invention relates to a kind of thermo-electric generation technology of heat-exchanging method, particularly adopt low boiling working fluid and water (comprising seawater, salt solution and the selected aqueous solution, as follows) directly to contact the method for carrying out heat exchange.Be applicable in ocean thermal energy conversion, salt lake thermo-electric generation and the waste heat thermo-electric generation.

The method of exchange heat in vaporizer and the condenser in the existing thermo-electric generation station all is with heat exchange equipment low boiling working fluid and water to be separated to carry out exchange heat.But owing to use heat exchange equipment, increased investment, affected heat-transfer effect simultaneously, therefore, all how to have improved the heat-transfer coefficient of this equipment at present in research.Particularly in the ocean thermal different power plant, because temperature range is little, it is big to handle the seawater amount, all using huge, complicated, expensive heat exchange equipment, the heat exchange equipment that 8 multitube garden cartridge type devices are arranged in 160,000 kilowatts of power stations as the design of american lockheed company, 22.2 meters of each garden tube diameters are made up of the titanium pipe of 51 millimeters of 120,000 long 16 meters external diameters.Point out on P234 to 235 page in " generation of electricity by new energy " book of compiling in collaboration with according to old tin wide grade of Xi'an Communications University: " heat exchanger (vaporizer and condenser) is the key equipment of ocean thermal different power plant, and its expense accounts for 50% of whole power station expense.Therefore, require the big heat exchanger of trial-production heat-transfer coefficient, have only enhancing heat transfer, could reduce heat transfer area, make equipment miniaturization, this is not only favourable economically, and can reduce the pressure loss, and reduce station service, also promptly reach the purpose that increases the sending end output power.Reach the practicability of ocean thermal energy conversion, successful key is to make the big heat exchanger of heat-transfer coefficient.If the technology of heat exchanger makes progress, then can reduce the cost in power station greatly ".

The objective of the invention is and in thermo-electric generation, to save heat exchange equipment, avoid the problems referred to above of bringing owing to this equipment of use.

Invention is achieved in that selects low boiling working fluids water insoluble and that proportion is different with water for use.Because it is water insoluble, low boiling working fluid just can directly contact with water and carry out heat exchange, because proportion difference, low boiling working fluid and water can be divided into automatically that two-layer (low boiling working fluid that proportion is lighter than water just floats on the surface after the heat exchange, the low boiling working fluid that proportion is heavier than water just sinks under water), can extract the low boiling working fluid after the liquefaction out repetitive cycling like this and use.

Advantage of the present invention is that seawater directly contacts with low boiling working fluid, can improve heat-transfer effect and generated output owing to save heat exchange equipment, saves investment and reduces volume etc.Now be that example is described as follows with the ocean thermal energy conversion: (1) improves heat-transfer effect, and this is that heat conduction, convection current, three kinds of forms of radiation all exist because of direct contact heat transfer.(2) increase generated output, this is because of the temperature difference in conducting heat, and has improved the number of degrees of available seawater lifting temperature, makes generated output be increased to original 2 to 3 times.(3) save construction investment, this is because can save the heat exchange equipment expense that accounts for whole power station investment 50%, adds the increase of generated output, and the investment funds of estimating every kilowatt of equipment like this only need original 25%.(4) area in the available marine site of increase, this is because requiring the sea and the seabed seawater temperature difference to be 20 ℃ originally just has available value, existing needs 15 ℃ and gets final product.(5) can avoid marine growth to the heat exchange equipment absorption problem.(6) utilize Ocean thermal energy to create advantage in a large number for ocean thermal energy conversion practicability.

The concrete mode that the present invention realizes is that example is described below with the ocean thermal energy conversion owing to adopt the heat change method different with existing ocean thermal energy conversion, so method is achieved at first will determine following some:

(1) select suitable working medium for use, promptly to select for use be insoluble to seawater and proportion different with seawater can be compared to the light low boiling working fluid of seawater most, its boiling point is preferably between-40 ℃～-20 ℃ between-60～10 ℃.Simultaneously the working medium source wants sufficient, produces easily, and inexpensive, safety and free from environmental pollution etc. meets the low boiling working fluid of above-mentioned condition.There are some working medium such as propadiene to choose.

(2) determine the degree of depth of container for evaporation and CONDENSATE POT, because seawater will enter container for evaporation or CONDENSATE POT and directly contact with low boiling working fluid and carry out heat exchange, but the low boiling working fluid in the container has certain vapour tension at normal temperatures and adds that liquid in container also has certain hydraulic pressure, therefore the pressure of seawater must just can enter greater than pressure in the container, utilizes seawater to have certain hydraulic pressure at certain depth at this and reaches.The vapor pressure of now establishing low boiling working fluid is P ₁, the seawater in the container is P at the hydraulic pressure of inlet ₂, it is sea water advanced for h to establish selected inlet, then requires h to be a bit larger tham (P ₁+ P ₂-P ₀)/(d), P ₀Be atmospheric pressure; D is a sea water specific gravity.Inlet's external sea water hydraulic can enter container automatically greater than pressure in the container like this.

Respectively container for evaporation and CONDENSATE POT are calculated according to following formula, determine its degree of depth.

(3) increase the remaining working medium device of recovery, absolute water-fast material does not have, so-called water-fast material is comparatively speaking, so always there is the low boiling working fluid of denier water-soluble, in order to reclaim these working medium, to on container for evaporation and CONDENSATE POT are discharged the pipeline of seawater, install and reclaim remaining working medium device (if the working medium quantity of discharging with seawater seldom, and working medium low price, adjusting its funds is worth below 1/10 at generated energy, and working medium can be installed without this when environment is not polluted).

Below in conjunction with accompanying drawing structure of the present invention, working principle and process are described in further detail.

Fig. 1 is the thermo-electric generation system sketch of direct contact heat exchange process.

Fig. 2 reclaims remaining working medium device sketch.

Fig. 3 is that dividing potential drop reclaims working medium device structural representation.

With reference to Fig. 1, automatically constantly (hydraulic refrigerant (12) is from CONDENSATE POT (14) with low boiling liquid refrigerant (12) in the inflow container for evaporation (19) by pipeline (4) and one-way valve (22) through preventing filter screen (3) that foreign material enter when sea temperature seawater, send into through pipeline (8) by pump (9)) contact, the heat that working medium absorbs in the warm seawater (20) is gasificated into high compressed steam, high compressed steam goes to push away Vortex turbine generator (7) generating through piping (6), the low-pressure steam of being discharged by turbo machine (7) contacts with the seabed Mare Frigoris water (13) of process filter screen (16) and pipeline (18) inflow in CONDENSATE POT (14), Mare Frigoris water (13) absorbs the heat in the refrigerant vapor, make working medium be liquefied as liquid, liquid refrigerant (12) is lighter than seawater, float over immediately above the seawater (13), extract liquid refrigerant (12) out pressurization back sending back in the container for evaporation (19) by pump (9) and recycle again by pipeline (8).By the continuous circulation of this low boiling working fluid (12), i.e. generating sustainably.Drain into marine by one-way valve (21), pipeline (5) and the remaining working medium device of recovery (2) seawater (20) extraction of being lowered the temperature in the container for evaporation (19) by pump (1).Drain into marine by one-way valve (17), pipeline (15) and the remaining working medium device of recovery (10) Mare Frigoris water (13) extraction that is heated up in the CONDENSATE POT (14) by pump (11).

With reference to Fig. 2, because the pressure in container for evaporation or the CONDENSATE POT is bigger, and the gas working medium that is dissolved in the seawater is directly proportional with gas pressure, thereby the working medium quantity that is dissolved in the seawater wants many than normal pressure is following, adopt the decompression method in order to reclaim working medium, reduce gas pressure intensity till the pressure also more much lower than normal pressure, most of can the effusion of working medium that is dissolved in like this in the seawater is recovered, structurally adopt dividing potential drop to reclaim, can reduce the energy consumption of pressurizeing when device volume is sent working medium back to minimizing than under low pressure once reclaiming like this.Now according to the size of chamber pressure, the selected n of branch level reclaims, and every grade of pressure reduces by half, and promptly pressure is P in container ₁The time, then the first order is (P ₁)/2; The second level is (P ₁)/(2 ²); The n level is (P1)/(2n).Total like this n dividing potential drop reclaims the working medium device, and the mounting point of each dividing potential drop recovery working medium device should be at the hydraulic pressure and (P of seawater ₁)/(2 ⁿ) on the height that equates, as h ₁=(P ₁)/(2d); h ₂=(P ₁)/(2 ²D); h _n=(P ₁)/(2 ⁿD); D is a sea water specific gravity.In addition in order to guarantee that seawater can be a bit larger tham atmospheric pressure P in the outlet port ₀, its $\mathrm{h\; ＞}\frac{P_0-\frac{{\mathrm{<figure-callout\; id="1"\; label="P"\; filenames="85105909\_DRIMG1.png"\; state="\{\{state\}\}">P</figure-callout>}}_1}{2^n}}{d}$

。Its working procedure is that the seawater that is discharged from advances along pipeline (3), when first dividing potential drop of flowing through reclaims working medium device (1), formerly is dissolved in that working medium has part with (P in the seawater ₁The pressure of)/2 is overflowed and is entered first dividing potential drop and reclaim in the working medium device (1), when second dividing potential drop of flowing through reclaims working medium device (2), formerly is dissolved in that working medium has part with (P in the seawater ₁)/(2 ²) pressure overflow and to enter second dividing potential drop and reclaim in the working medium device (2) ... when the n dividing potential drop of flowing through reclaimed working medium device (n), the former working medium that is dissolved in the seawater had part with (P ₁)/(2 ⁿ) pressure overflow and to enter the n dividing potential drop and reclaim in the working medium device (n), when the seawater overall process of flowing through is drained into when marine, to have and formerly be dissolved in the seawater most of remaining working medium and overflow and be recovered, there have fraction to be brought to be marine, from then on find out that n more better, but increase structure, so to decide according to actual conditions.It is 4 to 6 comparatively suitable that the general n maximum value is got.Each reclaims gaseous working medium that working medium device reclaims and sent back to CONDENSATE POT (, the merit that can reduce when sending consumed low than container for evaporation because of pressure in the CONDENSATE POT) by gas working medium outer pipe (4) quilt through pressurizeing after.

With reference to Fig. 3, when seawater when pipeline (11) is flowed through effusion collection box (8), because it is little to add gas pressure intensity, thereby some effusion of working medium that is dissolved in the seawater enters in the effusion collection box (8), to be mixed in the seawater working medium because proportion lighter than seawater, add the pressure that at this moment itself had and be a bit larger tham pressure in the case again, enter in the effusion collection box (8) so also from seawater, overflow.Structurally seawater flow through one section parallel distance is arranged in the casing and on box plate, make wave-like and some gardens rod of burn-oning etc. mainly be allow seawater by the time stirring is arranged, make working medium fully overflow (can load onto stirrer in case of necessity).Seawer outlet is in the bottom, mainly is in order to prevent that working medium from flowing out by pipeline (6) with seawater again.Can make the pressure in the capsule be slightly smaller than (P owing to can adjust the weight of the weight (3) that is added on the rubber pocket (2) ₁)/(2 ⁿ) pressure (n can be 1,2,3 ... a certain numerical value among the n), so gas working medium just can be in piping (7), one-way valve (5) flow to the rubber pocket (2) of pressurized tank (4), be that utricule is when expanding into the top when filling gas working medium in the rubber pocket (2).Automatically open compression pump (1), because the pressure that pump (1) is added on the capsule is a bit larger tham the interior pressure of CONDENSATE POT, at this moment rubber pocket (2) shrinks, and gas working medium is depressed in the CONDENSATE POT through gas working medium outer pipe (10) by one-way valve (9).

Claims (6)

1, a kind of thermo-electric generation technology [Fig. 1] of heat-exchanging method, feature of the present invention are to adopt directly to contact low boiling working fluid [12] and water [20], [13] (comprising seawater, salt solution and the selected aqueous solution, as follows) method of carrying out heat exchange.

2,, it is characterized in that selecting for use low boiling working fluids (12) water insoluble and that proportion is different with water according to the method that claim 1 adopted.

3,, it is characterized in that utilizing seawater to have certain hydraulic pressure and make seawater can enter container for evaporation (19) or CONDENSATE POT (14) automatically at certain depth according to the method that claim 1 adopted.

4,, it is characterized in that adopting increase recovery remaining working medium device (2), (10) to reclaim micro-working medium according to the method that claim 1 adopted.

5, device according to claim 4 (Fig. 2) is characterized in that adopting dividing potential drop to reclaim working medium apparatus (1), (2) ... (n) and recovery working medium are all sent CONDENSATE POT back to.

6, device according to claim 5 (Fig. 3), it is characterized in that adopting one section parallel distance is arranged in effusion collection box (8) and on box plate, make wave-like and the garden rod of the some of burn-oning etc. allow seawater by the time stirring (can load onto stirrer in case of necessity) is arranged and the weight (3) adjusted on the rubber pocket (2) is controlled pressure utricule in, make the working medium back recovery of fully overflowing.

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