Quartz sand is combined binary nitric acid Molten Salt Heat Transfer heat storage medium and preparation method thereof
Technical field
The present invention relates to the heat-accumulating heat-transfer complex media for solar light-heat power-generation, more particularly to a kind of quartz sand is answered
Close binary nitric acid Molten Salt Heat Transfer heat storage medium and preparation method thereof.
Background technology
In industrial accumulation of energy and solar light-heat power-generation technology, the heat-accumulating heat-transfer medium used at present be mainly free gas and water,
The metals such as conduction oil, fuse salt, sodium and aluminium.Fused salt is because with extensive temperature in use scope, low-steam pressure, low viscosity, well
Stability, many characteristics such as low cost turn into the heat transfer heat storage medium that potentiality are had much in solar light-heat power-generation technology, into
For at present using more, more ripe heat transfer heat storage medium.
Requirement of the solar light-heat power-generation to medium of fused salt is higher, it is necessary to meet various thermodynamics, chemistry and economics
Condition.Thermodynamic condition requirement:Alap fusing point and boiling point as high as possible, good heat conductivity, specific heat capacity are big, viscosity
It is low.Electrochemical conditions requirement:Heat endurance is good, and corrosivity is small, nontoxic, and nonflammable explosive, system is safe and reliable.Economic condition will
Ask:Components of molten salt wide material sources, it is cheap.Fused salt mixt is relatively low relative to one pack system fused salt fusing point, can also be kept at 500 DEG C
Preferable heat endurance, it is small to container and piping material corrosivity, it is particularly suitable for high temperature heat transfer heat storage medium.
Nitric acid molten salt system raw material sources are extensive, cheap, corrosivity is small and will not heat point typically below 500 DEG C
Solution, therefore compared with other fused salts, nitric acid fused salt has very big advantage.At present, the power station institute of external solar light-heat power-generation
The heat transfer heat storage medium used is mainly binary nitric acid salt system(40%KNO3- 60%NaNO3)With ternary nitric acid salt system
(KNO3-NaNO3-NaNO2).The operating temperature range of binary nitric acid salt system is 260-565 DEG C, and ceiling temperature is higher to compare reason
Think, but fusing point is higher, causes maintenance cost during obnubilation too high.Nitric acid molten salt system has that heat of solution is smaller, thermal conductivity is low
Shortcoming, therefore when in use easily produce hot-spot.The binary nitric acid molten salt system that the country is generally used is 55%KNO3-
45%NaNO2, 130-500 DEG C of operating temperature range, its fusing point is greatly lowered, and reduces maintenance cost, but the upper limit is used
Temperature is also accordingly reduced.
In order to solve the above problems, Chinese patent 201110425668.7 discloses a kind of KNO3-NaNO3-Ca(NO3)2Body
System, 180-550 DEG C of operating temperature range, compared with binary nitric acid salt system, its fusing point is greatly lowered, and reduces and safeguards into
This.But calcium nitrate heat endurance is bad, heat is decomposed to 132 DEG C.Oxidizing, oxygen is released in heating, meets organic matter, sulphur etc.
Occur burning and explode.
Chinese patent application 00111406.9 discloses a kind of LiNO3-KNO3-NaNO3-NaNO2System, its operating temperature
Scope is 250 DEG C -550 DEG C, and the upper limit working temperature of this system is higher than ternary nitric acid salt system, reaches 550 DEG C, but its lower limit
Operating temperature is also enhanced, and causes maintenance cost during obnubilation to increase, and LiNO3Addition cause its corrosivity increase, cost
Increase.
United States Patent (USP) US007588694B1 discloses a kind of LiNO3-KNO3-NaNO3-Ca(NO3)2System, its fusing point is less than
100 DEG C, upper limit temperature in use is higher than 500 DEG C, but LiNO3Addition add the corrosivity and cost of fused salt.
Quartz sand is one kind of ceramic material, its unique molecular chain structure, crystal shape and lattice variations rule, makes it
There is small high temperature resistant, thermal coefficient of expansion, high-insulation, anti-oxidant, resistant to chemical etching, the hair in many high-tech products
More and more important effect is waved, manufacture glass, refractory material, smelting duriron, flux for metallurgy, ceramic grinding material is often used as
Material, the raw material of casting;Industrial heat storage is done by choosing in large quantities simultaneously.
So far, do not see to be added to quartz sand in binary nitric acid fused salt and be used as industrial accumulation of energy and solar energy high temperature
The report of the heat transfer heat storage medium in heat utilization field.
The content of the invention
Blank of the present invention based on above-mentioned field and demand there is provided a kind of new heat transfer heat storage medium and preparation method thereof,
The upper limit temperature in use of the medium is high, and the corrosivity for equipment is low and material cost is also very low, overcomes current binary nitric acid
The defect that fused salt is present, the technical scheme is that:
1. a kind of quartz sand is combined binary nitric acid Molten Salt Heat Transfer heat storage medium, it is characterised in that:The heat transfer heat storage medium
It is to add quartz sand in binary nitric acid molten salt system to be composited.
2. quartz sand according to claim 1 is combined binary nitric acid Molten Salt Heat Transfer heat storage medium, the binary nitric acid
Molten salt system accounts for the 50~99% of heat transfer heat storage medium gross weight, and the quartz sand accounts for the 1~50% of heat transfer heat storage medium gross weight.
3. quartz sand according to claim 1 is combined binary nitric acid Molten Salt Heat Transfer heat storage medium, the binary nitric acid
Molten salt system account for heat transfer heat storage medium gross weight 50~90%, the quartz sand account for heat transfer heat storage medium gross weight 10~
50%。
4. quartz sand according to claim 1 is combined binary nitric acid Molten Salt Heat Transfer heat storage medium, the binary nitric acid
Molten salt system account for heat transfer heat storage medium gross weight 50~80%, the quartz sand account for heat transfer heat storage medium gross weight 20~
50%。
5. quartz sand according to claim 1 is combined binary nitric acid Molten Salt Heat Transfer heat storage medium, the binary nitric acid
Molten salt system account for heat transfer heat storage medium gross weight 60~80%, the quartz sand account for heat transfer heat storage medium gross weight 20~
40%。
6. quartz sand according to claim 1 is combined binary nitric acid Molten Salt Heat Transfer heat storage medium, the binary nitric acid
Molten salt system accounts for the 60~70% of heat transfer heat storage medium gross weight, and the quartz sand accounts for the 30~40% of heat transfer heat storage medium gross weight
7. binary nitric acid Molten Salt Heat Transfer heat storage medium, described two are combined according to any described quartz sand of claim 1~6
First nitric acid molten salt system is KNO3-NaNO3System:Wherein potassium nitrate:30-60 parts;Sodium nitrate:30-60 parts.
8. binary nitric acid Molten Salt Heat Transfer heat storage medium, described two are combined according to any described quartz sand of claim 1~6
First nitric acid molten salt system is KNO3-NaNO2System:Wherein potassium nitrate:30-60 parts;Natrium nitrosum:40-70 parts.
9. any described quartz sand of claim 1~8 is combined binary nitric acid Molten Salt Heat Transfer heat storage medium in industrial accumulation of energy
Or the purposes in solar light-heat power-generation.
10. the side of binary nitric acid Molten Salt Heat Transfer heat storage medium is combined for preparing any quartz sand of claim 1~8
Method, the equipment includes heat power supply device, the fused salt tank of sandwich(2), air-flow crushing drier(3), prilling granulator(5-1), it is cold
But device(5-2)And output device;
The heat power supply device includes heat carrier bearing cavity, the heat carrier bearing cavity and the interlayer inner chamber(13)Between lead to
Cross heat carrier pipeline(20-1)Connection;
The fused salt tank(2), air-flow crushing drier(3), prilling granulator(5-1), cooling device(5-2)And output device
Between by fused salt pipeline to connection, the fused salt pipeline is by the interlayer inner chamber(13)Bottom stretch out and enter air-flow crushing
Drier(3)Upper end;The air-flow crushing drier(3)Lower end and heat exchanger(4)It is connected;
The heat power supply device refers to solar thermal collection system(9), portable electric tracing(10)Or separate control and parallel connection
Solar thermal collection system(9)With portable electric tracing(10);
The solar thermal collection system(9)With the heat carrier pipeline between the fused salt tank(20)It is set to separate control
Two, wherein being provided with high-temperature storage tank on one(1);The high-temperature storage tank(1)With the fused salt tank of the sandwich(2)
Between be provided with heat carrier pump(19);
The fused salt tank of the sandwich(2)With the air-flow crushing drier(3)Between fused salt pipeline on be provided with it is molten
Salt pump(14);
The fused salt tank of the sandwich(2)Interlayer intracavity bottom and the heat exchanger(4)Between pass through one section heat carry
Body pipeline(20-2)It is connected;
The heat exchanger(4)Pass through one section of heat carrier pipeline between the heat power supply device(20-3)It is connected, it is described
Heat carrier pipeline(20-3)On be provided with low-temperature storage tank(18), the low-temperature storage tank(18)The heat carrier pipeline at two ends(20-
3)On be provided with heat carrier pump(16)、(17);
The fused salt tank of the sandwich(2)Also include agitating device(11)And charging aperture(12);
The output device includes feed bin successively(6), packing device(7)And/or storage device(8);
Step is as follows:
The raw material of the binary nitric acid molten salt system constituted in proportion is added to the fused salt tank of the sandwich(2)In, open
Dynamic heat power supply device is heated to be proportionally added into the quartz sand after molten condition, and continuation, which is heated and stirred to molten salt system, is uniformly
Only;
The composite fused salt of homogeneous heating is evacuated to air-flow crushing drier(3)In, air-flow crushing and drying are carried out, stone is obtained
Sand is combined nitric acid Molten Salt Heat Transfer heat storage medium, then is exported after granulation and cooling by output device.
The fused salt Preparation equipment used in the above method.
The present invention is first from composite of the quartz sand as nitric acid fused salt, and quartz sand is a kind of hard, wear-resisting, chemistry
The stable silicate mineral of performance, its main component is SiO2, a small amount of impurity component such as Fe is often contained in mineral2O3、Al2O3、
CaO、MgO、Na2O etc..About 1723 DEG C of fusing point, about 2230 DEG C of boiling point, with good high temperature resistant, anti-oxidant and resistant to chemical etching
Performance.Quartz sand for the present invention is more than 75% common quartz sand using dioxide-containing silica.
It is demonstrated experimentally that in binary nitric acid molten salt system add quartz sand prepare obtained by heat transfer heat storage medium, industry into
This is low, little to hold over system corrosivity, and also has the following advantages and actively imitate compared with former binary nitric acid molten salt system
Really:
The heat transfer property of the existing nitric acid fused salt of heat storage medium 1. composite fused salt prepared by the present invention is conducted heat, is improved hot steady again
Qualitative and upper limit temperature in use, the freezing point of fused salt does not change substantially.
2. the latent heat of phase change of Molten Salt Heat Transfer heat storage medium prepared by the present invention is big, energy storage density is high, reduces to accumulation of heat system
The requirement of size of uniting and energy, capacity usage ratio is high, good energy-conserving effect.
3. the heat absorption of Molten Salt Heat Transfer heat storage medium prepared by the present invention and heat storage capacity are good, thermal conductivity factor is significantly improved, and is led
Hot property is greatly increased, and overcomes that binary nitric acid fused salt heat conductivility is poor, and the shortcoming of easy hot-spot can be widely used for solar energy
Photo-thermal power generation technical field.
In the preferred embodiments of the invention, quartz sand accounts for 1~50%, and quartz sand content is higher, reduces cost more obvious;
The ceiling temperature that binary nitric acid fused salt had both been can guarantee that in the range of this 20~30% is improved, and can guarantee that fusing point is not raised again;Separately
Outside, the thinner heat transfer of the quartz sand particle degree of introducing is more uniform.
Technical term:
Fusing point:The fusing point that quartz sand obtained by the present invention is combined binary nitric acid Molten Salt Heat Transfer heat storage medium is using poor
Show scanner at ambient pressure, measured value during the heating heat transfer heat storage medium.
Present invention also offers the preparation technology of the fused salt for the prepare with scale present invention, its step depends on a set of
The innovative point and advantage of the equipment for inventing proposition, the set technique and equipment are as follows:
Technique is as follows:
1. the different component of molten salt system is sequentially added into fused salt tank in a certain order, in certain temperature and pressure
Under the conditions of, be heated to fused salt viscosity in fused salt tank can mechanical agitation when, start mechanical agitation uniform to system for a period of time.By
Heat power supply device provides the energy needed for heating, and portable electric tracing or solar energy heating may be selected in heat power supply device.If in
The solar energy of aggregation, environmental protection and energy saving can be used directly in material scene, such as solar energy thermo-power station.
2. opening high-temperature melting salt pump, discharging opening is opened, uniform molten salt system in fused salt tank from air-flow crushing drier
Top is injected, while the bottom of hot-air from air-flow crushing drier blasts drier, the two is reverse mode.Purpose:Make
The fused salt mixed system of liquid phase is directly forming the powdered of uniform drying after air-flow crushing drier, is on the one hand easy to bag
Take on and sell.Still further aspect is performance stable homogeneous when using.The powdered fused salt obtained from pneumatic conveyer dryer is through cooling device
It is down to after room temperature and is put into feed bin, packs, storage.
3., can be by the heat carrier in fused salt tank interlayer in the case where heat power supply device is solar thermal collection system(High temperature
Conduction oil or fused salt or overheated steam)Dredge into heat exchanger for heating required hot-air, take full advantage of fused salt
The waste heat of heat carrier after tank is used.The heat utilization rate of the technique is improved on the whole.
Advantage 1:
The heat power supply device of the present invention provides following three kinds of schemes:
The heat that scheme one, the present invention are provided using the solar energy of aggregation is used as thermal source, energy-conserving and environment-protective.Can be using four kinds of sides
Formula provides thermal source:Slot type, tower, dish-style, the Jing Chang aggregation solar energy of linear Fresnel formula solar light-heat power-generation mode.From into
The preferred slot type of angle of this and technology maturity and tower.
Mode one:From photo-thermal power generation slot type Jing Chang as aggregation solar energy mode, pass through the high temperature in thermal-collecting tube
Heat carrier directly heats fused salt tank.High-temperature heat carrier common at present is high-temperature molten salt, conduction oil, overheated steam, in slot type
Preferred conduction oil in mirror.
Mode two:From photo-thermal power generation tower Jing Chang as aggregation solar energy mode, pass through the high temperature in heat dump
Heat carrier connects heating fused salt tank.High-temperature heat carrier common at present is high-temperature molten salt, conduction oil, overheated steam, in tower mirror
Preferred fused salt in.
Scheme two, thermal source can be also provided using portable electric tracing, portable electric tracing is different from the winding electricity of traditional type
Heating tape, maintenance enhanced convenience is simple.
Scheme three, solar thermal collection system and portable electric tracing independent control and use in parallel, the two can be formed mutually
Benefit is acted on, such as when solar radiation is inadequate, can be supplemented with electric tracing.
Advantage 2:
Heat into the hot-air of air-flow crushing drier comes from the waste heat of the heat carrier in fused salt tank interlayer, maximum
The utilization heat of efficiency.
Advantage 3:
The temperature of fused salt tank, pressure controllable.
Advantage 4:
Final products particle fine uniform.
Brief description of the drawings
The structural representation of fused salt Preparation equipment used in Fig. 1 present invention process;
Wherein 1- high-temperature storage tank, 2- fused salt tanks, 3- air-flow crushing driers, 4- heat exchangers, 5-1- prilling granulators,
5-2- cooling devices, 6- feed bins, 7- packing devices, 8- storage devices, 9- solar thermal collection systems, 10- movable type electric tracings,
11- agitating devices, 12- charging apertures, 13- interlayers inner chamber, 14- pump for liquid salts, 15- air blowers, 16,17,19- heat carrier pumps, 18- is low
Warm holding vessel, 20- heat carrier pipelines.
Embodiment
With reference to specific embodiment, the present invention will be described in detail.
1st, experiment material:
Common quartz sand(Dioxide-containing silica is more than 75%), 100 mesh are purchased from Shandong Hong Tai quartz sands factory.
Potassium nitrate, sodium nitrate, natrium nitrosum, technical pure level, general chemical article company are commercially available.
Method:
The preparation method that quartz sand of the present invention is combined nitric acid fused salt has two kinds of selections:
Formula of the step 1. as listed by table 1 prepares the material of composition binary nitric acid molten salt system, is put into reactor, heats
Stirring makes solid melt completely, is then incubated 0.5-1h, and heating-up temperature is 80-120 DEG C of the fused salt phase transition temperature above.
Under step 2. stirring condition, quartz sand is distributed in the binary nitric acid molten salt system of melting, continues to stir 1-2h,
Mixture jelly,
2nd, large-scale production is preferred to use following technique and supporting fused salt preparation facilities:Fused salt Preparation equipment:It is described to set
It is standby to include heat power supply device, sandwich inner chamber(13)Fused salt tank(2), air-flow crushing drier(3), prilling granulator(5-1), cooling
Device(5-2)And output device;
In use, the raw material of the binary nitric acid molten salt system constituted in proportion to be added to the fused salt tank of the sandwich
(2)In, start heat power supply device and be heated to be proportionally added into the quartz sand after molten condition, continue to be heated to molten salt system uniform
Untill;
The composite fused salt of homogeneous heating is evacuated to air-flow crushing drier(3)In, air-flow crushing and drying are carried out, stone is obtained
Sand is combined binary nitric acid Molten Salt Heat Transfer heat storage medium, is exported finally by output device.
The heat power supply device includes heat carrier bearing cavity, the fused salt tank of the heat carrier bearing cavity and the sandwich(2)
Interlayer inner chamber(13)Between pass through heat carrier pipeline(20-1)Connection;
The interlayer inner chamber(13), air-flow crushing drier(3), prilling granulator(5-1), cooling device(5-2)And output
By fused salt pipeline to connection between device, the fused salt pipeline is by the interlayer inner chamber(13)Lower end stretch out and enter air-flow
Crush drier(3)Upper end;The air-flow crushing drier(3)Lower end and heat exchanger(4)It is connected;It is uniform in fused salt tank
Molten salt system from injection above air-flow crushing drier is entered, while the bottom of hot-air from air-flow crushing drier blasts drying
Device, the two is reverse mode.Purpose:The fused salt mixed system of liquid phase is set directly to form dry after air-flow crushing drier
It is dry uniform powdered, on the one hand it is easy to packaging to sell.Still further aspect is performance stable homogeneous when using;
The heat power supply device refers to solar thermal collection system(9), portable electric tracing(10)Or separate control and parallel connection
Solar thermal collection system(9)With portable electric tracing(10);Heat power supply device can be the single solar energy in the equipment
Collecting system 9 or individually portable electric tracing(10)Or the solar thermal collection system of separate control and parallel connection
(9)With portable electric tracing(10).
The solar thermal collection system(9)With the heat carrier pipeline between the fused salt tank(20-1)It is set to separate control
Two of system, wherein being provided with high-temperature storage tank on one(1).The solar thermal collection system(9)With the high-temperature storage tank
(1)Between be provided with valve, for controlling solar thermal collection system(9)In heat carrier to high-temperature storage tank(1)Middle flowing;Work as pass
When closing the valve, solar thermal collection system can be used(9)Or portable electric tracing(10)Directly heat heat carrier and then add
Heat salt cellar(2)Mode prepare high-temperature molten salt;When the energy is sufficient or fused salt tank need not be heated, solar energy collection can be opened
Hot systems and high-temperature storage tank(1)Between valve, the heat carrier heated by solar thermal collection system just can be by pipeline stream
To high-temperature storage tank and then store, when needing heating to prepare fused salt, can be pumped into by heat carrier pump (19) in interlayer
Chamber(13)And then heat fused salt tank(2)To prepare high-temperature molten salt.
The fused salt tank(2)With the air-flow crushing drier(3)Between fused salt pipeline on be provided with high-temperature melting salt pump
(14).For the fused salt after heating to be evacuated in air-flow crushing drier.
The interlayer inner chamber(13)Bottom and the heat exchanger(4)Between pass through one section of heat carrier pipeline(20-2)It is connected
It is logical.This section of heat carrier pipeline(20-2)For by interlayer inner chamber(13)In heat carrier guide to heat exchanger(4)In be used for plus
Hot-air needed for the hot equipment, so as to realize interlayer inner chamber(13)The waste heat of interior heat carrier is recycled, energy-conserving and environment-protective.
The heat exchanger(4)Pass through one section of heat carrier pipeline between the heat power supply device(20-3)It is connected, it is described
Heat carrier pipeline(20-3)On be provided with low-temperature storage tank(18).Lead to after being exhausted the cooling of the heat carrier of heat in a heat exchanger
Cross the heat carrier pipeline(20-3)On heat carrier pump(16)Pump into low-temperature storage tank, pass through heat carrier pump(17)Send back to
Recycled into heat power supply device.
The fused salt tank(2)Also include agitating device(11)And charging aperture(12).
The output device includes feed bin successively(6), packing device(7)And/or storage device(8).
All at least provided with a heat carrier pump on each section of heat carrier pipeline.
Be provided with each segment pipe in the said equipment abundance valve be used for control pipeline in material flowing and
Flow direction.The valve on heat carrier pipeline between heat power supply device and the fused salt tank of sandwich by control heat carrier conveying capacity and
Speed is so as to control heating-up temperature, and the fused salt tank itself carries pressure control device.
The binary nitric acid salt system KNO of embodiment 1~3.3-NaNO3Middle addition quartz sand prepares heat-accumulating heat-transfer medium
Formula of the step 1. as listed by table 1 prepares the material of composition binary nitric acid molten salt system, is put into reactor, heats
Stirring makes solid melt completely, is then incubated 0.5-1h, and heating-up temperature is 80-120 DEG C of the fused salt phase transition temperature above.
Under step 2. stirring condition, quartz sand is distributed in the binary nitric acid molten salt system of melting, continues to stir 1-2h,
Mixture jelly,
Binary nitric acid molten salt system formula in each embodiment of table 1.
Embodiment is numbered |
Binary nitric acid salt system |
Binary nitrate system formulation(Parts by weight) |
1 |
KNO3-NaNO3 |
Potassium nitrate:10 parts;Sodium nitrate:90 parts; |
2 |
|
Potassium nitrate:30 parts;Sodium nitrate:45 parts; |
3 |
|
Potassium nitrate:45 parts;Sodium nitrate:30 parts; |
The quartz sand of addition(Specification is 100 mesh)Gradient is carried out in the following proportions:
1st group:Quartz sand is combined in binary nitric acid Molten Salt Heat Transfer heat storage medium in three kinds of quartz sands and accounts for 1%, obtains the 1st~3
Product.
2nd group:Quartz sand is combined in binary nitric acid Molten Salt Heat Transfer heat storage medium in three kinds of quartz sands and accounts for 10%, obtains the 4th~6
Individual product.
3rd group:Quartz sand is combined in binary nitric acid Molten Salt Heat Transfer heat storage medium in three kinds of quartz sands and accounts for 20%, obtains the 7th~9
Individual product.
4th group:Quartz sand is combined in binary nitric acid Molten Salt Heat Transfer heat storage medium in three kinds of quartz sands and accounts for 30%, obtain the 10th~
12 products.
5th group:Quartz sand is combined in binary nitric acid Molten Salt Heat Transfer heat storage medium in three kinds of quartz sands and accounts for 40%, obtain the 13rd~
15 products.
6th group:Quartz sand is combined in binary nitric acid Molten Salt Heat Transfer heat storage medium in three kinds of quartz sands and accounts for 50%, obtain the 16th~
18 products.
The control of each product is the corresponding binary nitric acid fused salt of the product.
Step 3. latent heat of phase change is tested and fusing point test:
Carried out using general Differential Scanning Calorimeter DSC(Scanned under normal pressure).
Test result shows that compared with the control, latent heat of phase change is all significantly increased;
Quartz sand is combined binary nitric acid fused salt numbering KNO3-NaNO3Molten salt system percentage by weight is matched(It is also pair simultaneously
According to)
The test result of the fusing point of table 2.
Quartz sand is combined binary nitric acid fused salt numbering |
Fusing point DEG C |
Control:Potassium nitrate 10%;Sodium nitrate 90% |
270 |
1 |
250 |
4 |
254 |
7 |
256 |
10 |
270 |
13 |
274 |
16 |
278 |
Control:Potassium nitrate 40%;Sodium nitrate 60% |
220 |
2 |
205 |
5 |
207 |
8 |
203 |
11 |
219 |
14 |
228 |
17 |
231 |
Control:Potassium nitrate 60%;Sodium nitrate 40% |
210 |
3 |
198 |
6 |
199 |
9 |
193 |
12 |
210 |
15 |
213 |
18 |
212 |
And the 1st~3 set product fusing point has declined but not notable;The fusing point of 5th group and the 6th set product has somewhat been carried
It is high.
Step 4:Heat stability testing
Heat stability testing is carried out to preparing 18 kinds of heat transfer heat storage mediums and 3 kinds of control binary nitric acid fused salts.
Test is carried out using gravimetric method:18 kinds of fuse salts of the gained of embodiment 1~3 are respectively charged into the crucible of nickel,
It is put into temperature controlling stove and is heated, experiment is proceeded by from normal temperature, experiment crucible is taken out at regular intervals and is claimed with assay balance
Weight.If in a certain temperature section, the weight of sample is no longer reduced, then improves the temperature of temperature controlling stove.Then again when one section
Between take out experiment crucible weighed, to another stable state after be further continued for heat up.
The equilibrium temperature boundaries of four kinds of control binary nitric acid systems are to heat 100 hours at 550 DEG C, 550 DEG C, loss late
Up to 10%;Heating 30 hours, loss late is up to 5%., 710 is hot 100 hours, and loss late is heated 30 hours, loss late reaches up to 25%
13%。
Heat stability testing is carried out to 6 groups of 18 kinds of heat transfer heat storage mediums of the gained of embodiment 1~3,
Loss late statistical result at 3.550 DEG C of table
It can be seen that in the case where 550 DEG C are spent, adding quartz sand can make the heat endurance of each set product obvious relative to control
Improve.
Loss late statistical result at 4.710 DEG C of table
It can be seen that in the case where 710 DEG C are spent, add considerably less quartz sand, can make the heat endurance of each set product relative to
Control is significantly improved.
The binary nitric acid salt system KNO of embodiment 4~73-NaNO2Middle addition quartz sand prepares heat-accumulating heat-transfer medium
Formula of the step 1. as listed by table 4 prepares the material of composition binary nitric acid molten salt system, is put into reactor, heats
Stirring makes solid melt completely, is then incubated 0.5-1h, and heating-up temperature is 80-120 DEG C of the fused salt phase transition temperature above.
Under step 2. stirring condition, quartz sand is distributed in the binary nitric acid molten salt system of melting, continues to stir 1-2h,
Mixture jelly,
Binary nitric acid molten salt system formula in each embodiment of table 5.
Embodiment is numbered |
Binary nitric acid salt system |
Binary nitrate system formulation(Parts by weight) |
1 |
KNO3-NaNO2 |
Potassium nitrate:30 parts;Natrium nitrosum:70 parts; |
2 |
|
Potassium nitrate:40 parts;Natrium nitrosum:60 parts; |
3 |
|
Potassium nitrate:45 parts;Natrium nitrosum:55 parts; |
4 |
|
Potassium nitrate:55 parts;Natrium nitrosum:45 parts; |
The quartz sand of addition(Specification is 100 mesh)Gradient is carried out in the following proportions:
1st group:Quartz sand is combined in binary nitric acid Molten Salt Heat Transfer heat storage medium in four kinds of quartz sands and accounts for 1%, obtains the 1st~4
Product.
2nd group:Quartz sand is combined in binary nitric acid Molten Salt Heat Transfer heat storage medium in four kinds of quartz sands and accounts for 10%, obtains the 5th~8
Individual product.
3rd group:Quartz sand is combined in binary nitric acid Molten Salt Heat Transfer heat storage medium in four kinds of quartz sands and accounts for 20%, obtains the 9th~12
Individual product.
4th group:Quartz sand is combined in binary nitric acid Molten Salt Heat Transfer heat storage medium in four kinds of quartz sands and accounts for 30%, obtain the 13rd~
16 products.
5th group:Quartz sand is combined in binary nitric acid Molten Salt Heat Transfer heat storage medium in four kinds of quartz sands and accounts for 40%, obtain the 17th~
20 products.
6th group:Quartz sand is combined in binary nitric acid Molten Salt Heat Transfer heat storage medium in four kinds of quartz sands and accounts for 50%, obtain the 21st~
24 products.
The control of each product is the corresponding binary nitric acid fused salt of the product.
Step 3. latent heat of phase change is tested and fusing point test:
Carried out using general Differential Scanning Calorimeter DSC(Scanned under normal pressure).
Test result shows that compared with the control, latent heat of phase change is all significantly increased;
The test result of the fusing point of table 6.
Quartz sand is combined binary nitric acid fused salt numbering |
Fusing point DEG C |
Control:Potassium nitrate:30 parts;Natrium nitrosum:70 parts |
207 |
1 |
197 |
5 |
195 |
9 |
193 |
13 |
199 |
17 |
213 |
21 |
220 |
Control:Potassium nitrate:40 parts;Natrium nitrosum:60 parts |
133 |
2 |
125 |
6 |
118 |
10 |
115 |
14 |
123 |
18 |
140 |
22 |
142 |
Control:Potassium nitrate:45 parts;Natrium nitrosum:55 parts |
132 |
3 |
122 |
7 |
121 |
11 |
119 |
15 |
126 |
19 |
138 |
23 |
141 |
Control:Potassium nitrate:55 parts;Natrium nitrosum:45 parts |
133 |
4 |
126 |
8 |
120 |
12 |
117 |
16 |
125 |
20 |
139 |
24 |
145 |
And the 1st~4 set product fusing point has declined but not notable;The fusing point of 5th group and the 6th set product has somewhat been carried
It is high.
Step 4:Heat stability testing
Heat stability testing is carried out to preparing 24 kinds of heat transfer heat storage mediums and 4 kinds of control binary nitric acid fused salts.
Test is carried out using gravimetric method:24 kinds of fuse salts of the gained of embodiment 4~7 are respectively charged into the crucible of nickel,
It is put into temperature controlling stove and is heated, experiment is proceeded by from normal temperature, experiment crucible is taken out at regular intervals and is claimed with assay balance
Weight.If in a certain temperature section, the weight of sample is no longer reduced, then improves the temperature of temperature controlling stove.Then again when one section
Between take out experiment crucible weighed, to another stable state after be further continued for heat up.
The equilibrium temperature boundaries of four kinds of control binary nitric acid systems are to heat 100 hours at 500 DEG C, 500 DEG C, loss late
Up to 12%;Heating 30 hours, loss late is up to 5%., heat 100 hours at 600 DEG C, loss late is up to 22%;Heating 30 hours, is damaged
Mistake rate is up to 12%.
Heat stability testing is carried out to 6 groups of 24 kinds of heat transfer heat storage mediums of the gained of embodiment 4~7,
Loss late statistical result at 7.500 DEG C of table
It can be seen that in the case where 500 DEG C are spent, adding quartz sand can make the heat endurance of each set product obvious relative to control
Improve.
Loss late statistical result at 8.600 DEG C of table
It can be seen that in the case where 600 DEG C are spent, add considerably less quartz sand, can make the heat endurance of each set product relative to
Control is significantly improved.