Background technology
Solar energy is more satisfactory new forms of energy, but has ageing problem on utilizing, and the energy of being accepted between sunshine period surpasses required, but can't play a role after the sunset.Thereby unnecessary energy stores during how at sunshine, to be used for the continuous service of post sunset system, promptly gets and has a surplus with tonifying for the deficiency, becomes and realizes the solar energy thermal-power-generating key issue of operation continuously.
Prior art has been used multiple heat-storage medium in the storage of solar energy technology.Obtain composite phase-change material (shaping phase-change material) in the laboratory though be reported in recent years, support as matrix with certain material, in order to store heat, but there is the low shortcoming of thermal conductivity factor, but also when existing phase-change material to undergo phase transition, because the hidden danger of revealing takes place to leak in the variation of volume easily.In addition, industrial also have use ternary aluminum alloy in order to as storage material, it has negative effect for thermal storage performance (as parameters such as phase-change thermal storages), and heat accumulating itself carries out solid-liquid phase change repeatedly in the course of the work, and impurity element will influence its serviceability and service life.Existing industrialized solar energy thermal-power-generating unit utilizes inorganic salts to do heat accumulating more, but the shortcoming that inorganic salts existed cold-peace to be separated in phase transition process, influenced heat storage capacity, service life is also shorter, and inorganic salts have toxicity, leak breaking out of fire easily, and leak the meeting pollution on the environment.
Present international solar energy heat utilization stocking system mainly contains two jars of directly accumulation of heats, two jars of indirect accumulation of heats and single jar of mesolimnion regenerative apparatus:
As shown in Figure 1, heat transfer medium is heated in the Salar light-gathering field two jars of direct energy source storage systems (Two-tank Direct Energy Storage System), also directly is stored in the deep fat jar as storage medium simultaneously.Deep fat after being heated is driven by oil pump, through steam generator, and obtains the vapours generating.When the Salar light-gathering field does not have heat when input, for example night, heat storage can has stored certain heat because of accepting the input of Salar light-gathering field heat daytime, still can act on steam generator in the certain hour, produces steam and generates electricity; After the cooling of the heat transfer medium behind the steam generator, flow back to cooling tank; When the Salar light-gathering field when heat storage can provides heat, on for example day fine daytime, the back that is heated of the heat transfer medium in cold jar flows in the heat jar, finishes energy absorption and storage.This system architecture complexity, required two heat jar costs are higher, and because of the temperature upper limit of heat transfer medium is lower, its heat storage capacity also is restricted.
Two jar indirectly can source storage systems (Two-tank Indirect Energy Storage System) as shown in Figure 2, cold relatively fuse salt arrives the heat exchanger from cold salt cellar under the driving of fusion salt pump, and obtains heat, becomes the fuse salt of heat; The direction that cold fuse salt flows in heat exchanger is opposite with the direction that heat transfer medium after the Salar light-gathering field is heated flows through; Heat fusing salt after being heated is stored under the driving of pump for liquid salts in the heat jar.When heat-storage medium generated electricity, heat fusing salt was from heat jar outflow, and through steam generator, heat fusing salt becomes cold fuse salt, flows into cold jar.The two jars of directly heat reservoirs of comparing, this system can store more heat; Its shortcoming is the heat storage can that still needs two costlinesses, and needs to drive corrosive high-temperature fusion salt, and needs heat accumulation salt is preheated after solidifying, and makes it become the fuse salt state, so that drive; Complicated integral structure, the operating cost height.
Above dual mode all can make whole heat energy storages obtain the high-grade utilization in theory, and the heat-storage medium that flows out the heat jar at last also can keep the condition of high temperature, therefore can obtain the steam of high-temperature from start to finish, thereby have the sustainable high efficiency generating efficiency.
As shown in Figure 3, single jar top is heat fusing salt to single jar of mesolimnion energy storage system (Single-tank Thermocline Energy Storage System), and the bottom is the fuse salt of relative low temperature; When heat accumulation, the fuse salt inflow heat exchanger of the low temperature of bottom, the high-temperature heat-transfer medium generation heat exchange with having accepted solar heat obtains the temperature close with it, flows into single jar heat fusing salt zone, top afterwards, finishes the heat accumulation process; When heat release, the fuse salt of high temperature flows out from single tank top, through over-heat-exchanger, heat is given heat transfer medium, and heat transfer medium is through the steam generator generating, and high-temperature fusion salt temperature reduces, and flows into single pot bottom from heat exchanger, finishes heat release.This heat storage can has vertical temperature gradient, even after commercialization or the industrialization, whole cost is still expensive, and system still can't avoid the corrosivity of high-temperature fusion salt and the heating and melting process after the curing.
Described above is to use at present commonplace heat reservoir in the world, in order to obtain the target that thermal energy storage and high-grade are utilized, the equal more complicated of the overall structure of existing system, make and operating cost high; In addition, above-mentioned heat-storage medium is poisonous, and has strong corrosivity, and existence is easy to generate problems such as fire, contaminated environment after revealing.
The utility model content
The utility model is at the above-mentioned problems in the prior art, a kind of low cost, environmental protection are provided, have had the heat-storing device of natural mesolimnion (Thermocline), this apparatus structure is simple, reliable, can efficiently realize the utilization of heat energy high-grade, can be applicable to various heat accumulations and use, particularly Solar Energy Heat Utilization System.
According to the utility model, a kind of heat-storing device is provided, comprise closed heat accumulation space, place heat-storage medium, heat in the described heat accumulation space to be conveyed into the insulation construction that device, heat change output device and be positioned at outside, described closed heat accumulation space, it is characterized in that, described closed heat accumulation space is a strip, described heat is conveyed into device and heat and changes output device and run through and be arranged in the described closed heat accumulation space, and finishes in this airtight heat accumulation space that heat passes and heat is changed.
Preferably, cross section, described airtight strip heat accumulation space is that circle or similar round or cross sectional shape and size can change in the axial direction, and the ratio of the representative section diameter/length in this airtight strip heat accumulation space more preferably is between 0.001~0.05 less than 0.1.
Preferably, described heat-storage medium is magnesia, heat storage brick, metal, rock, sand or conduction oil; Further, in described heat-storage medium, place sheet metal, the wire of highly heat-conductive material and fill, radially the selectivity layout.
Preferably, described heat is conveyed into device and comprises heat transfer input pipe and the interior heat transfer medium of heat transfer input pipe, and described heat transfer input pipe is through described closed heat accumulation space; Further, on the described heat transfer input pipe fin is set.
Preferably, described heat is changed output device and is comprised heat exchange efferent duct and the interior heat transferring medium of heat exchange efferent duct, and described heat exchange efferent duct is through described closed heat accumulation space; Further, on the heat exchange efferent duct fin being set, is helical form with described heat exchange efferent duct in described closed heat accumulation space.
Preferably, described insulation construction comprises outer wall, vacuum heat-insulation screen and inwall, and described outer wall and inwall keep vacuum state between being, described vacuum heat-insulation screen is the multilayer heat reflection screen that is positioned at outer wall and inner wall space; Further, forming the space between the outer wall of described insulation construction and the inwall is the dynamic vacuum state, and this space is the more piece vacuum structure.
Preferably, described heat-storing device integral body is certain inclination, and the vertical drop of the two-port in described closed heat accumulation space and the length ratio of heat-storing device are rake ratio, and this rake ratio is preferably between 0.01~0.1 less than 1.
Preferably, the heat energy of described heat-storing device is from solar energy.
Preferably, all or part of below ground that places of described heat-storing device.
Preferably, described heat-storing device vertically is built in more than the ground, as the heat-storing device of point type focused solar energy receiving system.
Airtight strip heat-storing device of the present utility model is because the lower cost materials such as yellow sand, rock, magnesia, foamed cement, pottery, metallic plate that have drawn from, so this apparatus cost is low, and stable performance, have cost performance preferably, be particularly suitable for large-scale promotion solar energy and utilize needed heat-storing device.
The specific embodiment
Fig. 4 is the heat-storing device overall structure schematic diagram of embodiment of the present utility model.As shown in the figure, the heat-storing device 1 of present embodiment is airtight strip, comprises closed heat accumulation space 2, places heat-storage medium 3, heat in this closed heat accumulation space 2 to be conveyed into device 4, heat is changed output device 5 and external insulation structure 13; Described closed heat accumulation space 2 is a strip, and the cross section is that circle or similar round or cross sectional shape and size can change in the axial direction, or cross sectional shape and size can change the formed area of circle that its corresponding cross-sectional area is an equivalent diameter in the axial direction; The volume in described closed heat accumulation space 2 is set according to required quantity of heat storage and heat storage capacity parameter, and the ratio of its equivalent diameter and length (or height) is less than 0.1, and preferred value is less than 0.05 greater than 0.001; Described airtight strip heat-storing device 1 integral body is certain inclination; Described length is similar with the length of the single-row slot type of line focus solar attachment or Fresnel array in slot light collection equipment; Described height is set by concrete parameter in point type focused solar energy receiving system.The vertical drop of heat-storing device two-port and the length ratio of heat-storing device are rake ratio, this rake ratio is 0.01~1, be preferably between 0.01~0.1, to reduce the convection heat transfer' heat-transfer by convection effect of the gas in the heat-storage medium, good assurance the stability of the formed thermograde of low side temperature of the high-end temperature of high end position and lower position, reduce the axial temperature diffusion tendency.
The heat that the absorption plant of the parabola groove correspondence of Salar light-gathering field is connected in native system is conveyed into device 4, and the inlet that heat is conveyed into device 4 is the high-end of inclination, exports the low side into tilting; The rake ratio of supposing optimization is 0.01, the length of airtight strip heat-storing device 1 is 200m, the inclined high-end of then airtight strip heat-storing device 1 exceeds 2m than low side, making things convenient for heat to be conveyed into that heat in the device 4 pass and heat are changed, the heat of Salar light-gathering field is changed to airtight strip heat-storing device 1 inside.Heat is conveyed into device 4 and comprises heat transfer input pipe 9 and heat transfer medium, heat is conveyed into pipe 9 in closed heat accumulation space 2, be arranged in the lower part in closed heat accumulation space 2, heat is conveyed into and arranges heat transfer medium in the pipe 9, heat is conveyed into pipe 9 and is optimized for finned heat transfer input pipe, to increase its heat transfer area, improve heat transfer rate to heat-storage medium 3; Heat transfer medium preferable alloy or inorganic salts or conduction oil, metal are preferably SODIUM METAL, zinc, aluminium or its alloy, and inorganic salts are preferably nitrate, carbonate, chlorate or salt-mixture etc.Heat is changed the top that output device 5 is positioned at closed heat accumulation space 2, and through wherein, it comprises heat exchange efferent duct 11 and heat transferring medium, and heat exchange efferent duct 11 is in closed heat accumulation space 2, arrange heat transferring medium in the heat exchange efferent duct 11, this heat transferring medium is water or air or conduction oil; This heat exchange output device 5 can swap out the heat in closed heat accumulation space 2, can obtain high-grade water vapour or hot-air constantly, and high-temperature water vapor or hot-air enter thermo-mechanical power generation.Heat exchange efferent duct 11 preferred disposed outside fins or be designed to helical form, and fin gap or helix pitch can be different at diverse location, other space in closed heat accumulation space 2 is full of heat-storage medium 3, heat-storage medium 3 can use liquid heat-storage medium and solid-state heat-storage medium, liquid heat-storage medium can be heat accumulation oil or conduction oil, fuse salt, these are described above, its weak point is arranged, for example poisonous, easily leak, pollute, the cost height, or limited by the temperature upper limit of itself, problems such as the heat that exists unit volume to store is few, the preferred heat-storage medium 3 of the utility model is the solid heat-storage medium, more be optimized for heat storage brick, metal, rock and sand etc., optimum turns to magnesia (MgO, as dead burnt magnesite sand), because of magnesia medium thermal capacitance height, density is big, so have very high volumetric specific heat capacity, has very high heat storage capacity, high heat storage temperature can reach 1000 ℃, and cost is lower, be easy to storage, handling safety, environment there is not any negative effect, no leakage problem exists, stopped the environmental issue of existing heat-storage medium, in addition, in order to remedy the not too high shortcoming of magnesia conductivity, in preferred embodiment of the present utility model, can also radially in heat accumulation magnesia medium, add sheet metal, highly heat-conductive materials such as silk, to promote the radially capacity of heat transmission of heat accumulation magnesia medium, make axial capacity of heat transmission not have significant change simultaneously as far as possible; And variable cross-section layout on axial length, to obtain required different temperatures section different heat storage capacity and heat insulation effect, heat accumulation magnesia medium does not have phase transformation in whole process, belong to the sensible heat heat accumulation, do not have tangible stereomutation, overcome contingent chemical reaction in existing most of heat-storage medium phase transformation, leak, pollute poisonous or the like deficiency.Airtight rectangular property heat-storing device 1 preferably is arranged in below ground, and the cross-ventilation so that air in the minimizing surrounding enviroment and airtight strip heat-storing device 1 form reduces the thermal loss that produces because of the surrounding air convection current in the heat accumulation process.
As shown in Figure 4, the structure for more clear explanation closed heat accumulation space 2 is divided into A section, B section and C section with it and is described.Interior heat transferring medium 12 traffic directions of the traffic direction of heat transfer mediums and heat exchange efferent duct 11 are opposite in the input pipe of heat transfer shown in the figure 9, heat transfer medium enters from the C section port in closed heat accumulation space 2, transfer heat in closed heat accumulation space 2 is finished the heat accumulation process; Heat transferring medium enters from the A section port in closed heat accumulation space 2, takes away heat in closed heat accumulation space 2, finishes heat transfer process.
Fig. 5 is the procedure chart that is heated of the heat-storing device of embodiment of the present utility model.Suppose that heat-storing device 1 is through after continuing heat release night, the temperature of heat-storage medium 3 is all reduced to about 150~250 ℃ in the closed heat accumulation space 2, when accepting heat daytime, heat is conveyed into device 4 inlets from heat and enters, when being step 5-a, heat transfer medium is flowed through in the closed heat accumulation space 2, begin to heat heat-storage medium 3 from the C section, pass through the B section midway, heat transfer medium 10 has discharged most of heat, during through the A section in the closed heat accumulation space 2 of strip, the heat of this circulation of heat transfer medium discharges to be finished, and its most heat changes C section to the closed heat accumulation space 2 of strip to the B section; Through after the heat transfer of certain hour, be step 5-b, it is close with the heat transfer medium temperature of input time that the temperature of C section port has obtained, and this moment, heat transfer medium discharged certain heat through C section port position, and the heat transfer medium temperature descends to some extent, during through the B section, heat transfer medium continues release heat, and bulk temperature continues to descend, and has certain heat to discharge again at A section port, heat transfer medium temperature in whole process is all descending, and heat-storage medium 3 bulk temperatures are all rising; Again after after a while, be step 5-c, the C section port in closed heat accumulation space 2 to heat-storage medium 3 temperature in the space of B section all obtain the temperature with the heat transfer medium input time substantially, this moment, heat transfer medium was less to B section release heat through C section port, it is mainly to heat-storage medium 3 heating of B section to A section port, pass through certain hour again after, i.e. step 5-d, it is consistent that heat-storage medium 3 temperature in the whole closed heat accumulation space 2 all reach, and has for example 550~650 ℃ of very high temperature simultaneously.At the initial stage of being heated, promptly hour in axial direction can there be tangible thermograde in quantity of heat storage in the closed heat accumulation space 2, and inlet is high, exports lowly, but the porch also can obtain to absorb the approaching high-temperature zone of temperature.Along with quantity of heat storage increases, this temperature province can enlarge gradually, to the exit development, until final closed heat accumulation space 2 state that all reaches a high temperature.
The utility model is owing to adopt closed heat accumulation space 2 designs of elongated shape, heat energy is very low in the transmission speed of spatial axis direction, no matter under the low or high state of quantity of heat storage, all can keep clearly thermograde at certain hour, form natural good mesolimnion effect; And the cross-sectional dimension in closed heat accumulation space is less, the heat transfer input pipe transmits relatively easy many of heat to heat-storage medium, and transmit heat in order further to quicken radially to go up, the utility model upwards designs fin in the footpath of heat exchange efferent duct 11 or fill sheet metal, silk in heat-storage medium 3, and can closed heat accumulation space 2 axially on be designed to variable cross-section, to make things convenient for the more heat input.
Fig. 6 is the heat-storing device heat transfer process figure of embodiment of the present utility model.As shown in the figure, after finishing whole heat accumulation processes, heat-storage medium 3 temperature basically identicals in the whole closed heat accumulation space 2, has very high temperature grade, for example 650 ℃, closed heat accumulation space 2 need be changed heat to heat transferring medium, and the heat transferring medium of high temperature is sent to hot machine with heat and generates electricity afterwards.Described heat exchange output device 5 places 2 tops, closed heat accumulation space, structure can be designed to helical form or add fin structure, and the gap of spiral intervals or fin can be provided with difference in different zones, mainly be in order to obtain more heat exchange area, make in its shortest time and finish swapping out of institute's calorific requirement, heat is changed heat transferring medium and heat in the output device 5, and to be conveyed into the direction that device 4 interior heat transfer mediums advance opposite, heat transfer medium is gone into from the C section port in airtight strip heat accumulation space 2, go out from A section port, and heat transferring medium is gone into from the A section port in airtight strip heat accumulation space 2, goes out from C end port.The beginning of heat exchange, be after the step 6-a, heat transferring medium is water for example, go into from A section port, liquid heat transfer medium for example becomes water vapour rapidly after the water heat absorption, through the B section, carry out overheated heating, substantially obtain and the close outlet temperature of heat-storage medium 3 maximum temperatures from C section exit, because of heat-storage medium 3 is that airtight strip structure example such as length are 200m, heat transferring medium is through the overheated output device 5 that changes, before the B of heat-storing device 1 section, just obtain to be superheated to 650 ℃ steam, and in the process of the heat-storage medium 3 of process back segment, Yin Wendu is close, substantially do not need the release from the heat of the B section in closed heat accumulation space 2 and C section, the temperature of the heat-storage medium 3 of B section and C section remains unchanged; When the temperature of A section descends, heat transferring medium for example water/water vapour does not reach required high-temperature, therefore in continuing to move ahead, continue to absorb heat, rise to required maximum temperature numerical value up to temperature, this moment, resorbent heat was seldom from heat exchange efferent duct periphery heat-storage medium 3, the temperature of the B section after this position and the heat-storage medium 3 of C section does not descend substantially, whole process is the process that heat-storage medium 3 is lowered the temperature to the C section gradually from the A section, but the airtight strip heat-storing device 1 of the utility model design, that makes is very long, 200m for example, whole elongated, heat-storage medium 3, for example the thermal conductivity of magnesia is approximately 3~5W/ (m*K) in the time of 550 ℃, heat-storage medium 3 temperature conduction ability in the axial direction is very low, thermograde on can in the regular hour, forming axially, promptly this closed heat accumulation space 2 can form a natural mesolimnion in the process of heat exchange, and the C section can both keep the temperature high-grade at last up to heat exchange, make heat transferring medium to the beginning all keep high-grade output extremely eventually, keep high efficiency.After the heat exchange of a period of time of process step 6-b, the temperature of the heat-storage medium 3 of A section reduces, and the temperature of B section also begins to reduce, but the range of decrease is less, and the temperature of C section remains unchanged always, when heat transferring medium leaves from C section port, is also keeping and C section high temperature recently.After passing through the heat exchange of a period of time of step 6-c again, the huge range of decrease has taken place in A section temperature, and B section temperature begins to have had tangible reduction, and this moment the C section temperature still keep high temperature constant; Final stage in heat exchange, be step 6-d, it is violent that the temperature of A section and B section all descends, and the temperature of C section still keeps high temperature at this moment, heat transferring medium 12 is after A section and the preheating of B section, enter the C section,, export from C section port at the heat of C section acceptance part with through after overheated, still the temperature with C section output port is close for the temperature of this moment, up to the heat exchange last moment, heat transfer medium all keeps high-grade heat output, has high efficiency.
What be worth stressing is, because adopt closed heat accumulation space 2 designs of elongated shape, heat energy is lower in the transmittability of spatial axis direction, no matter under the low or high state of quantity of heat storage, all can form natural good mesolimnion effect in certain hour maintenance thermograde clearly; And the cross-sectional dimension in closed heat accumulation space is less, heat-storage medium transmits relatively easy many of heat to the heat exchange efferent duct, and in order further to quicken directly upwards to swap out heat, the utility model upwards designs fin in the footpath of heat exchange efferent duct 11 or fill sheet metal, wire in heat-storage medium 3, and can closed heat accumulation space 2 axially on be designed to variable cross-section, to make things convenient for more heat to swap out, reach the purpose that two-forty deposits, withdraws heat.
Existing heat-storing device mostly is diameter with highly close cylindrical, and the heat-storage medium 3 in the heat-storing device does not have the transfer of locus, can't form good mesolimnion, after the somewhere of heat-storing device descends because of the heat exchange temperature, the inevitable low-temperature region transfer of heat of the high-temperature area of heat-storing device to heat-storing device, in long time not, reach the balance of temperature, cause balanced decline of bulk temperature of whole heat-storing device, for example to begin be 550 ℃ to heat-storage medium 3 temperature of heat-storing device inside, and the temperature of the heat transferring medium that begins to export is also near 550 ℃; After the heat exchange of a period of time, the bulk temperature of heat-storing device begins to descend, and for example temperature equalization ground arrives 300 ℃, and the highest output temperature of the heat transferring medium 12 of output this moment can only be near 300 ℃, thereby reduced heat grade; Can not finish the output of the long-time high-temperature parameter steam that continues, reduce generating efficiency.
Fig. 7 is the high vacuum sandwich construction schematic diagram of the external insulation structure 13 of the utility model heat-storing device, and Fig. 8 is the local enlarged diagram of two layers of nested structure among Fig. 7.The storage of identical heat roughly needs close reservoir volume, but the strip of structure makes its more traditional heat storage can have bigger surface area, about generally speaking 5~30 times, big insulation surface area is the unfavorable factor that causes thermal loss, and therefore very good adiabatic heat-insulation structure is the prerequisite that guarantees height heat accumulation efficient.
Adopt the high vacuum sandwich construction to have very high insulating efficiency among the embodiment of the present utility model, because it has stopped three kinds of modes of heat transmission effectively: convection current, conduction, radiation.As mentioned before, elongated project organization has less sectional dimension also provides specific implementation for the vacuum insulation structure possibility.As shown in the figure, concrete insulation construction 13 structures comprise vacuum heat-insulation screen 8, vacuum casting 7 and outer wall layer 6 from inside to outside; Mezzanine space between closed heat accumulation space 2 and the vacuum casting 7 adopts high-vacuum technology, and interlayer is provided with adsorbent, effectively stops the convection heat transfer' heat-transfer by convection that air causes; Interlayer between closed heat accumulation space and the vacuum casting adopts the multi-layer heat preserving structure, uses polishing stainless steel, aluminium and silver-plated etc. to have the radiation shield 14 that low-emissivity material is made, and effectively reduces insulation construction 13 radiation of closed heat accumulation space 2 to low temperature; Adopt to support between the interlayer of closed heat accumulation space 2 and vacuum casting 7 and the grommet support, described mezzanine space is closed heat accumulation space 2, radiation shield 14 and grommet support 15 outside interior, and it can be set to multilayer nest, Fig. 7 be illustrated as two layers nested.Adopt special end socket to connect between a plurality of heat transferring medium construction units, effectively stoped the heat conduction loss between inwall 7 and the outer wall layer 6.Outer wall layer 6 materials are foam concrete or rock wool, glass fibre etc., and this type of material heat transfer coefficient is low, and wide material sources can reduce the cost of manufacture of device.
Fig. 9 is the more piece vacuum structure schematic diagram of embodiment of the present utility model.A kind of airtight strip heat-storing device be set to the elongate strip shape, for example every group length 200m for obtaining good external insulation performance, forms the space and is preferably vacuum state between the outer wall of insulation construction and the inwall; Because of structural design is longer, the vacuum state of keeping long structure is not easy to operate, and is simultaneously with high costs, in case and certain position vacuum leak appears, whole system all can not be in good keeping warm mode, and is unfavorable to whole heat-insulation system.For overcoming this problem, Fig. 9 embodiment of the present utility model provides a kind of more piece vacuum structure, need the structure of vacuum insulation to be divided into the individuality of several vacuum structures strip, it is the more piece vacuum structure, as shown in the figure, the multilayer nest structure that the closed heat accumulation space 2 of certain distance is arranged as shown in Figure 8, unit multilayer nest structure is built in vacuum state or dynamic vacuum state.Described dynamic vacuum state can continuously or off and on be vacuumized and obtain the more piece insulation construction structure of 2 outsides, closed heat accumulation space by vacuum pumping pump.
Figure 10 is the radiation shield 14 reflectance coating schematic diagrames of embodiment of the present utility model, and as shown in the figure, radiation shield 14 is a foil, stainless steel for example, and tow sides have high temperature resistant low emissivity coatings 16, for example aluminium coated or silver coating; And penetralia is the highest because of its temperature, can design and use thin polishing metal thermal insulation layer, for example high polish copper or silver.In addition, for further strengthening the heat accumulation effect, can be with all or part of below ground that places of the heat-storing device of present embodiment.
The utility model can be realized good thermal storage performance, and another embodiment has provided concrete technical indicator.Among this embodiment, needing to store daylighting area is 10000m
2Solar heat, the concrete layout in Salar light-gathering field is that the width of parabola groove is 5m, every group length is 100m, one has 20 groups, the average solar irradiation density in Beijing area is 0.8kW/m
2, the efficient of accepting of photo-thermal is 0.6, accepts 6 hours illumination heat energy, then every group of parabolic heat of accepting is 0.8kW/m
2* 100*5m
2* 0.6*6h=1440kWh; If the specific heat capacity of the heat-storage medium magnesia in the closed heat accumulation space 2 is 1.047~1.086J/ (g*K) (when the temperature of magnesia is 400~600 ℃), get its mean value 1.037J/ (g*K), its solid density is 3.3g/cm
3, actual pile factor is 0.8, then its actual density is 2.64g/cm
3, after the temperature of magnesia was accepted the heat of sunray, temperature increased to 550 ℃ from 250 ℃, and temperature difference is 300 ℃; Then the energy of 1kg magnesia energy heat accumulation is: 1kg*1.037kJ/ (kg*K) * 300K=311.1kJ=0.0864kWh; Be that the 1kg magnesia temperature difference is 300 ℃ of heats that can store 0.0864kWh, the weight that can obtain total magnesia thus is 1440/0.0864=16667kg ≈ 16.7T; Volume is 16667kg/2640kg/m
3=6.31m
3, present embodiment closed heat accumulation space is the closed heat accumulation space of strip, every group length is 100m, and the inwall 7 diameter 0.283m in every group of closed heat accumulation space 2, inwall 7 external surface areas in closed heat accumulation space 2 are approximately 89m
2The outer wall 3 in closed heat accumulation space 2 is made up of with insulating barrier the reflection multilayer screen, suppose that radiation shield emissivity at high temperature is 0.05, the emissivity of the bladder layer in closed heat accumulation space 2 is 0.3, isolate by the very low ceramic grommet support of thermal conductivity factor between every layer of radiation shield, its heat transfer loss can ignore herein; The thermal conductivity factor of outer wall layer is 0.05W/ (m*K) (below 250 ℃), after system receives heat, the temperature of the magnesia in inner closed heat accumulation space 2 is 550 ℃, heat accumulation 24 hours, suppose system allow thermal loss account for total acceptance heat 10%:, the number of plies of the radiation shield that then needs altogether is 8 layers; The diameter of outer wall layer calculates and is approximately 0.806m, and the thickness of outer wall layer is (0.806-0.283)/2=0.262m=262mm.If allow thermal loss account for total acceptance heat 5%, the number of plies of the radiation shield that then needs altogether is the 17-18 layer, the diameter of outer wall layer calculates and is approximately 0.806m, the thickness of outer wall layer is (0.806-0.283)/2=0.262m=262mm.
So the overall size in the closed heat accumulation space of present embodiment is, it is cylindrical that closed heat accumulation space integral body is airtight strip, be total up to 20 groups, the length in single group closed heat accumulation space is 100m, the diameter in closed heat accumulation space is 0.283m, actual desirable 0.3~0.4m, the diameter of outer wall layer is 0.806m, actual desirable 0.8~0.9m, the thickness of outer wall layer is 262mm, interlayer between outer wall layer and the closed heat accumulation space has 8 layers radiation shield 14, passes through the grommet support of low conductivity between every layer.The present embodiment actual motion proves that this closed heat accumulation space 550 ℃ heat-storage medium can be kept 24 hours and heat loss is less than 10% of hot total amount; If the number of plies of radiation shield is 18 layers, the diameter of outer wall layer is constant, and this closed heat accumulation space 550 ℃ heat-storage medium can be kept 24 hours and heat loss is less than 5% of hot total amount.
Figure 11 be utility model embodiment vertically stand on the above heat-storing device schematic diagram in ground.This heat-storing device can be applied to the point type solar collecting device, heat-storing device 1 vertically stands on ground, be that rake ratio is 1, internal structure and principle thereof and rake ratio are identical less than the heat-storing device of 1 linear solar energy receiving device, promptly comprise closed heat accumulation space 2, place the heat-storage medium 3 in this closed heat accumulation space 2, and heat is conveyed into device 4 and heat is changed output device 5.Closed heat accumulation space 2 is a strip, and the two ends, circular section are airtight; Heat-storage medium 3 is preferably magnesia; Heat transfer medium is preferably the solid heat transfer medium; Heat transferring medium is preferably water or air heat transferring medium.
The utility model can be realized good thermal storage performance, and an embodiment has provided concrete technical indicator.The heat of first business-like in the world center tower solar-electricity field PS10 of Spain's foundation in 2007, the center tower height 100m in this power station, solar electrical energy generation power is 11MW, heating power is 20MW
h, it uses the steam conduction and stores, and the storage time is 1 hour, supposes and accepts 7 hours illumination its every day, and then total end heat of its storage every day is 20MW
h* 8 hours=160MWh, supposition utilizes technology of the present utility model in the present embodiment, use airtight strip heat-storing device and magnesia heat-storage medium, be 300 ℃ according to the magnesia temperature difference of above analysis 1kg and can store 0.0864kWh, the total quality that then needs is 160MWh/0.0864kWh=1851851.85kg; Its bulk density is 2640kg/m
3, then its volume is 701.46m
3, being assumed to diameter and volume ratio is 0.05, and then the base diameter of its airtight strip heat-storing device is 3.547m, and the height of actual heat-storage medium is 70.94m, and the heat accumulation tower can be set to sunshine with top and accept part.
Obviously, under the prerequisite that does not depart from true spirit of the present utility model and scope, the utility model described here can have many variations.Therefore, the change that all it will be apparent to those skilled in the art that all should be included within the scope that these claims contain.The utility model scope required for protection is only limited by described claims.