WO2006111042A1

WO2006111042A1 - A moderate temperature heat storage material, a heat storage element and a heat accumulating and releasing device

Info

Publication number: WO2006111042A1
Application number: PCT/CN2005/000541
Authority: WO
Inventors: Zhihui Wang
Original assignee: Starford International Holdings Limited
Priority date: 2005-04-20
Filing date: 2005-04-20
Publication date: 2006-10-26

Abstract

A moderate temperature heat storage material is composed of B (OH)2. 8H20, Na(OH)2. H2O, sodium sulfate Na2SO4 , ferric powder Fe and water. A heat storage element with the above material includes a heat-transferring shell and fins for enhancing heat transfer efficiency. The shell may be a sealed columnar container, and the fins are arranged in the shell. Furthermore, the moderate temperature heat storage material is filled in the gaps formed in the inner chamber of the shell. A heat accumulating and releasing device comprises elements, which are arranged in m rows and n columns in a temperature-maintaining casing. A heat exchange coil is further provided on the upper side of the device. A heated distributor and a heating distributor are provided at the top and bottom of the device respectively. An inlet and an outlet for water, which are connected with a water -supplying system, are provided at two ends of the coil. The heated distributor is externally connected to an electric power source. An inlet and an outlet for water to heat space or other objects are provided in the front of the heating distributor. Water or other heat conductive medium is filled in the gaps formed in the casing.

Description

Medium temperature heat storage material, heat storage element and heat supply device composed of heat storage element

The present invention relates to a field of heat exchange, a step and a structure for performing heat exchange of a medium temperature heat storage material, a heat storage element including the heat storage material, and an energy storage heat supply device comprising the heat storage element .

Background technique

At present, energy shortages have constrained economic development and the improvement of people's living standards. Coal shortages, power shortages, and gas shortages have sounded energy alarms, saved primary energy, developed the use of renewable energy, and recovered and utilized waste heat. It is vital. China's power industry has developed rapidly in recent years, but the power supply tension has not been fundamentally improved. The main performances are: low grid load rate, large system peak-to-valley gap, rapid growth of urban life and commercial electricity consumption, and relative reduction of industrial electricity consumption. . This kind of reality promotes the development of comprehensive energy utilization technologies, and medium-temperature energy storage heating technology is one of its most critical technologies.

At present, the commonly used regenerative technologies are: atmospheric pressure water storage and high temperature water storage, solid phase high temperature storage. Due to the latent heat of decomposition (80 cal/g) of water at 0 °C and latent heat of vaporization (539 cal/g) at 10 CTC, the bulk density (lg/ml) and specific heat (lcal/g. °C) is small, so the latent heat of the water and the sensible heat storage density are small. The use of water for medium heat storage utilizes sensible heat characteristics: Atmospheric pressure water storage and high temperature water heat storage technology utilizes the temperature difference sensible heat characteristics of water. The heat storage density is small. The steam heat storage uses the latent heat of vaporization of water. Although the heat of vaporization is large, the steam density is small and the pressure is high, so the relative heat storage density is small. The word phase high temperature heat storage is to heat the solid molding material with an electric heating tube. By 400-700 °C, the heat stored in the high-temperature heat exchange is released, and the heat exchange device is complicated, the pressure is high, the safety performance is poor, the heat preservation is difficult, and the heat loss is large.

Summary of the invention

The technical problem to be solved by the present invention is to overcome the above-mentioned deficiencies of the prior art, and to provide a medium temperature heat storage material, a heat storage element including the heat storage material, and an energy storage heating device composed of the heat storage element, wherein the medium temperature storage The thermal material can fully utilize its heat storage and heat transfer characteristics without high-temperature heat storage. The heat storage element stores heat quickly and has good heat transfer effect. The energy storage heating device integrates heat storage, heat exchange and heat preservation, and has waste heat. Waste heat recovery, low-temperature electricity storage, heating, and domestic hot water supply.

The technical solution proposed by the present invention is:

A medium temperature heat storage material characterized in that it comprises the following raw materials by weight ratio:

Boron octahydrate [Β(0Η) ₂ ·8Η ₂ ·0]: 25%~40%;—sodium hydrate [Na(OH) ₂ ·3⁄4 -0] : 53. 5%~72. 3%; Sodium sulphate [Na ₂ S0 ₄ ] _: 0. 5%~1. 0% _; iron powder [Fe] _: 0. 2%~0. 5%; water [ · 0] _:

2% to 5%;

The medium temperature heat storage material is a translucent solid at a normal temperature, the density is 2000-2300 kg 'm- ³ , and the melting point temperature is 72-80. C, the heat of fusion is 290-300 kj · kg - ¹ , the specific heat capacity is 4. 5-5 kj · kg" ¹ · ¹ , the thermal conductivity is 0. 5-1. 0 kj · m- ¹ · ° ¹ · s- - A heat storage element composed of a medium temperature heat storage material, comprising: a heat transferable housing and a reinforced heat transfer sheet, wherein the housing is a sealable cylindrical body, and the reinforced heat conductive sheet is disposed therein The medium temperature phase change heat storage material is filled in the gap of the inner cavity of the casing;

The reinforced heat transfer sheet is a twisted structure made of a metal sheet;

The housing is a cylindrical housing having at least one asymmetric heat dissipation guide ring disposed thereon.

An energy storage and heating device comprising a heat storage element, comprising a box body, wherein: the box body is provided with a heat insulating layer, wherein the inner cavity is arranged with heat storage elements arranged in m rows and n columns, upper part A heat exchange coil is arranged, and a heating distributor and a heat distributor are respectively arranged at the top and the bottom, and the inlet and the outlet of the water supply system are connected at both ends of the tube, and the heat source is externally connected to the heat distributor, and the heat distributor is provided. The front end is placed outside the box, and is used as the inlet and outlet for heating and heating respectively; in the upper part and the lower part of the box, a temperature measuring probe is arranged, and a temperature sensor is arranged inside the probe tube, and the wire is electrically connected with the time temperature controller; The gap in the tank is filled with water or other heat transfer medium;

The heat storage elements are distributed in the number of m and n^l, and are fixed in the box by the heat storage mold rods, and the distance between the rod bodies is 5-20 mm.

The medium temperature heat storage material of the invention has high heat storage capacity, and the heat storage performance is stable and reliable.

The heat storage element of the invention has simple structure and easy processing, and the arrangement of the reinforcing heating sheet can increase the heat storage and heat transfer speed of the heat storage element itself, and improve the heat transfer effect; the asymmetric heat dissipation diversion ring provided on the casing can be increased The strength of the inner wall expands the outer surface area, accelerates the heat storage and heat release rate of the heat storage phase change material, and has high heat transfer performance.

The invention arranges a plurality of heat storage elements in a regular arrangement in an energy storage heating device, and is further provided with a heating method such as steam and electricity, which can integrate heating, heat storage, heat exchange and heat preservation, and has waste heat, waste heat recovery and low valley. The electric high-density energy storage heating device designed and manufactured by the electric heating, heating and domestic hot water is not only capable of independently supplying water and hot water, but also regulating the water temperature through the temperature regulating valve; Waste heat back correction page (Article 91) The charging and low-temperature electric heat storage function greatly reduces the initial investment and operating costs, and improves safety and comfort. The conventional regenerative devices such as atmospheric water storage, high-temperature water storage, and solid-phase high-temperature heat storage have fundamentally solved the problems of large volume, high pressure, high initial investment, high cost of use, and poor safety performance.

DRAWINGS

Figure 1 is a graph showing the heat storage characteristics of the heat storage material of the present invention;

2 is a graph showing the heat release characteristics of the heat storage material of the present invention;

Figure 3 is a schematic longitudinal sectional view of the heat storage element of the present invention;

Figure 4 is a structural view of the heat supply device of the present invention.

In the picture:

1. Box, 2. Insulation, 3. Seal back bend,

4. Thermal storage element, 41. Housing, 42. Plugging piece,

43. Strengthening the thermal conductive sheet, 44. Diversion support ring, 5. Heat exchange coil,

6. Phase change heat storage material, 7. Heating distributor, 8. Heating distributor,

9. Temperature probe, 10. Heat storage component divider, 11. Support,

12. Heating circulating water return, 13. Heating circulating water outlet, 14. Hot water outlet,

15. Cold water inlet, 16. Hot water supply temperature control valve, 17. Temperature controller,

18. Variable frequency speed control circulating pump, 19. Heat transfer medium, 20. Heat meter,

21. Tractor chassis, 22. Case cover, 23. Check □,

24. Level indicator.

detailed description

The invention relates to an inorganic heat storage material, which is a formula material which utilizes the phase change heat of an inorganic salt to achieve the purpose of heat storage and heat extraction. According to the temperature requirements, the main phase change components can be selected, and other necessary auxiliary components can be added. There are many varieties of inorganic salts, and a wide range of them can be combined with each other to bring about different heat storage properties and heat storage effects. The requirements for selecting a heat storage material are: 1) the phase transition temperature (such as melting point) is suitable; 2) the unit weight (or volume) of the latent heat is large; 3) the thermal stability is high; 4) the resources are abundant, the source is easy; Cheap; 6) low toxicity, low corrosivity. This indicates that the selection of Hi thermal materials should be considered in terms of phase transition temperature and phase change heat, and the phase transition temperature of the heat storage material can be changed by adjusting the formulation, different materials, different ratios, and phase transitions. The temperature is different. The invention provides a medium temperature heat storage The material has a heat conversion temperature of 7 0 -9 5 Ό, which includes the following raw materials by weight: Boron octahydrate [Β(0Η) ₂ · 8Η ₂ · 0] : 25%~40%, sodium monohydrate [Na (OH) ₂ · · 0]: 53.5%~72.3%, sulphuric acid [Na ₂ S0 ₄ ]: 0.5%~1.0%, iron [Fe]: 0.2%~0. 5%. Among the above raw materials, octahydrate borax [Β(0Η) ₂ ·8Η ₂ ·0] and sodium monohydrate [Na(0H) ₂ .3⁄4-0] are inorganic salts, which account for a large proportion of the total components. , especially sodium monohydrate [Na(OH) ₂ · 3⁄4 · 0], more than 50%, is a material with high heat storage capacity, its phase transition temperature (such as melting point) in the medium temperature range, unit weight (or volume) The latent heat is large, adding a small amount of three auxiliary additives such as sodium sulfate, water and iron powder. The source is easy, the price is cheap, the corrosion is small, the crystal can be raised, the suspect time is not generated, and the material is saved. Thermal performance is stable and reliable. 1, FIG. 2, through the heat storage material tests, formulations of the present invention provides a strong thermal storage and release characteristics of _Q

The phase change heat storage material of the invention has a translucent solid at a normal temperature, a density of 2000-2300 kg'm- ³ , a melting point temperature of 72--80 ° C, and a heat of fusion of 290-300 kj' kg- ¹ , specific heat capacity. For 4.5-5 kj · kg— ¹ · C— ', the thermal conductivity is 0.5 1.0 kj · πΓ ¹ · °(Τ · s—

The processing method of the intermediate temperature heat storage material of the present invention is: heating the above-mentioned parts by weight of octahydrate boron, and then heating and heating until the temperature is raised to 85 ° C to 90 ° C, respectively, adding parts by weight of water, a 7j sodium, iron powder. And sodium sulfate can be used.

According to the present invention, a heat storage element 4 is designed according to the above heat storage material. As shown in FIG. 3, it mainly comprises two heat transferable housings 41 and a reinforced heat transfer sheet 43, and the housing 41 is a metal cylindrical body. One end is first closed by the sealing piece 42 and can be realized by welding. The cylindrical inner cavity is provided with a reinforcing heat conducting sheet 43, and the medium temperature phase change heat storage material 6 is filled in the inner cavity of the casing 41, and can fill the reinforcing heat conducting sheet 43 and the shell. All the gaps between the inner walls of the body 41 make the entire casing 41 a heat storage element 4 with a phase change material. After the phase change heat storage material 6 is filled, the other end of the casing 41 is also closed by the sealing sheet 2. The arrangement of the reinforcing thermally conductive sheet 43 is mainly because the phase change heat storage material 6 itself is a material capable of liquid-solid conversion, and the heat transfer hysteresis of the inner position of the inner cavity of the casing 41 relative to the inner wall affects the crystal crystallization speed. Further, the heat storage and heat release effects of the heat storage element are affected, and the reinforcing heat conductive sheet 43 is disposed between the phase change heat storage materials 6, so that the heat propagation speed can be accelerated, and the phase change heat storage material 6 is ensured to be in the cavity of the casing 41. When stored in different positions, the heat storage and heat release rates are the same. At the same time, in order to ensure uniform heat transfer rate, the reinforced heat transfer sheet 43 is made of a metal sheet into a twist-like structure, and the structure can be processed at one time, and the material of the weight-matching material has the largest surface area, and thus the heat transfer surface thereof is also Larger, the best heat transfer effect. Correction page (Article 91) At least one asymmetric heat dissipating ring 45 is also machined on the housing 41 for one time forming during the cylindrical processing of the housing 41. The structure design is very easy to process and the cost is also low, which can increase the strength of the inner wall of the casing 41, prolong the life of the heat storage element 4, and increase the surface area of the casing 1 of the same weight to improve the heat storage element. The heat transfer area accelerates the heat storage and heat release rate of the heat storage phase change material 6, and can also cause a flow guiding action in the heat conductive medium to increase the gap between the plurality of heat storage elements when stacked. Further improve the heat transfer effect. In addition, it can also serve as a support for easy placement during handling. The working principle and workflow of the heat storage element 4 of the present invention are:

In the heat transfer medium of the heat storage element 4 1⁄2A 8 2 ° C - 130 ° C, the heat contained in the medium is uniformly transmitted to the phase change heat storage through the metal cylinder casing 41 and the plugging piece 42 and the reinforcing heat conducting sheet 43. Material 6, the temperature of the phase change heat storage material 6 is increased by the recommended weight, and the sensible heat is stored. When the temperature reaches the melting point (7 9 Ό), the phase change heat storage material 6 begins to melt, stores the latent heat, and all melts and reaches When the external heat transfer medium is at the same temperature, the heat storage process ends; when the temperature of the heat transfer medium is lower than the temperature of the phase change heat storage material 6, the phase change heat storage material 4 will pass through the metal cylinder case 41 and the plugging piece 42 and the reinforcing heat conductive sheet. 43 uniformly guides the heat medium to release heat, and the temperature gradually decreases. When the melting point (79 °C) is reached, the solidification begins and the latent heat is released. Below the melting point (79 °C), the latent heat of phase change is completely released, and the temperature continues. The lowering of the heat release process begins after the sensible heat is released and reaches the same temperature as the external heat transfer medium.

As shown in FIG. 4, the energy storage and heating device designed by the present invention comprises a box body 1 whose top is sealed by a box upper cover 22, and an upper inspection cover 23 is provided on the upper cover 22 of the box body, and the box body 1 can be observed. Internal condition. At the bottom of the box body 1, a support 11 can be provided. The support 11 13⁄4 can be fixed on the ground or a fixed position to become a fixed heat storage device, and a tractor chassis 21 can be added and fixed on the tractor. The entire device can be moved by the tractor to become a movable device. The inner wall of the casing 1 is provided with a heat insulating layer 2, which can prevent the heat from being rapidly radiated outward. The inner cavity of the casing 1 is filled with a heat conductive medium 19, which can be water or other heat conductive material, and the heat storage element is immersed in the heat conductive medium 19. The phase change heat storage material 6 in the heat storage element 4 has a melting point of 75-95 ° C and a heat of fusion of 50-75 kcal/kg. When the phase change heat storage material 6 reaches its melting point, the latent heat characteristic begins. Its endothermic, from solid to liquid; conversely, when the temperature of the phase change thermal storage material 6 falls below its melting point, its latent heat characteristics begin to release heat from liquid to solid. By providing the heat storage member 4 containing the phase change heat storage material 6 in the casing 1, the heat of the heat transfer medium 19 can be absorbed and stored, and then its heat energy can be released as needed to realize the conversion of its thermal energy. In order to improve the heat storage capacity and the effect of heat release, the heat storage element 4 may be provided in plurality as needed, and fixed and uniformly distributed in the casing 1 through the heat storage element separator 10, and may be evenly arranged in m rows and n columns. Where m and n^l are selected according to the heating demand and the heating area, the spacing between the components is 5-20 mm, which can increase the surface area of the heat storage element 4, increase the contact surface with the heat conductive medium 19, and improve the heat transfer capability.

In the upper part of the box body 1, a heat exchange coil 5 is arranged, which is in the shape of a serpentine snake, which is placed outside the box body through the C-type elbow, and is immersed in the heat transfer medium 19, at the two ports of the coil tube, respectively The cold water inlet 15 and the hot water outlet 14 are connected to the hot water supply system, and the cold water in the pipe can be heated by the heat exchange between the heat exchange coil 5 and the heat transfer medium 19 to increase the temperature of the cold water in the pipe, and the tap water is cooled from cold water. The inlet 15 enters the heating and becomes hot water, which can flow out from the hot water outlet to supply the user. Between the cold water inlet 15 and the hot water outlet 14, a water supply temperature regulating valve 16 is connected in parallel, which can be adjusted according to different seasons and different needs.

In the lower part of the box body 1, located below the heat storage element 4, a heating distributor 7 is provided, which can be made of a seamless steel pipe, which is provided with a plurality of circular holes of different apertures, and the outlet end of the distributor passes through and is welded to the casing 1 On the side wall, the inlet is externally connected to the heat recovery device, and the waste heat or waste heat collected by the heat recovery device can be sent into the inner cavity of the casing 1 through the small hole, and the heat energy is transmitted to the heat storage element 4 through the heat transfer medium 19, so that the inlet is realized. For the hot function, the outlet is provided with a heating circulation return port 12. Above the heat exchange coil 5, there is a heating distributor 8 whose front end passes through the tank 1 and is welded with a connecting flange, which is used as an inlet and outlet for heating and heating, and can be made of seamless steel pipe. There are a plurality of circular holes which are used for different pore diameters of the heat exchange, and are welded and sealed when passing through the two layers of the metal plates of the casing 1. The outlets of the circulating water outlets are connected in series with the circulating water outlets 13 through the outlet. The heating variable frequency speed regulation circulating pump 18 connected in series is connected to the heating system to continuously supply heat to the user.

In order to detect the heating temperature in real time, a heat meter 20 is connected in series to the heating and hot water supply pipes, and is connected to the heating circulating water outlet 13 and the domestic hot water outlet 14 respectively.

In the upper part and the lower part of the box body 1, a temperature measuring probe is also arranged. 9. A temperature sensor is arranged inside the probe tube, and the wire is electrically connected with the time temperature controller 17, so that the temperature of the heat conductive medium 19 in the box body 1 can be measured in real time.

The invention can recover and store a large amount of waste heat of a steel mill, a coking plant, a corundum plant, a calcium carbide plant, a brewery, and the like through the recovery device 2, and then connect to the present invention through a pipe, and transfer the recovered heat to the heat storage of the present invention. It is then sent to the heating user by the tractor, thereby achieving the design object of the present invention.

In summary, the present invention has significant breakthroughs in the recovery and utilization of waste heat, waste heat, planning and design of heat storage systems, and promotion and application of energy storage materials, and has a certain guiding role. The working process of the energy storage heating device of the invention:

Heat storage process:

The heat carrier medium (water above 90 ° C or 100 ° C - 13 CTC steam) of the external heat source is connected to the heating distributor 7 , and the heat contained therein enters the tank 1 through the heating distributor 7 and heats the heat transfer medium 19 thereof. The temperature of the heat transfer medium 19 is continuously increased while the heat is uniformly diffused and transmitted to the phase change heat storage material ⁶ through the outer wall of the heat storage element 4, and the phase change heat storage material ⁶ is gradually increased, and the phase transition temperature is not reached. Before the melting point, the heat storage element 4 stores sensible heat. However, when the phase change heat storage material 6 obtains sufficient heat, it will gradually undergo a lattice change--a phase change latent heat. When the phase change is over and the set temperature is reached, the heat storage process is completed, and the heat storage is sensible heat (60 - 95 °). C) Add latent heat, totaling approximately 92_95 kcal/k _g .

Heat release supply (hot water) process:

For the supply user, the supply and return water supply ports of the heating system are respectively connected to the outlet of the heat meter (20) of the movable heat storage device 14 and the heating water return port 12, and the phase change heat storage material 6 is The stored heat is uniformly transmitted to the heat-conducting medium 19--water through the outer wall of the heat storage element 4, so that the temperature of the water is raised, and the water can be heated to 45-80 ° C as needed, under the action of the heating variable frequency speed regulating circulating pump 18 The heated water flows out through the supply circulating water outlet 13 to supply heat to the heating system. When the phase change heat storage material 6 gradually releases the accumulated latent heat, a lattice change occurs - a solidification, the temperature begins to decrease and the sensible heat is released, and when the specified temperature (50-60 ° C) is reached, the heat release process ends. .

For the domestic hot water user, the heating circulating water outlet 13 of the present invention is first connected to the inlet of the user water supply system when the hot water is supplied, and the inlet is connected to the return water of the tap water pipe or the user hot water system, and the water supply temperature regulating valve 16 is adjusted. The required water supply temperature mixed with the recycled water or tap water, the heat supplied by the heat meter 20 according to the embodiment described in FIG. 3 and FIG. 4, if the heat storage element 4, the heat dissipation chute 45 and the heat exchange coil The arrangement of 5, the shape of the eve, and the replacement of the structure are other similar technical solutions, which are also within the scope of the present invention. The above is a specific embodiment of the present invention and the technical principle applied thereto. The equivalent changes made by the novel concept, and the functional effects produced by the novel concept are still beyond the scope of the specification and the drawings, and are within the scope of the present invention.

Claims

Rights request

A medium temperature heat storage material characterized in that it comprises a raw material of the following weight ratio:

Boron octahydrate [Β(0Η) ₂ · 8Η ₂ · 0]: 25%~ 40%;

-7j sodium [Na(OH) 2 · 3⁄4 · 0]: 53. 5% ~ 72. 3%;

Thioxa [Na ₂ S0 ₄ ]: 0. 5% ~ 1. 0%;

Iron powder [Fe]: 0. 2% 〜 0. 5%;

Water [3⁄4 · 0]: 2% ~ 5%.

2. The medium temperature heat storage material according to claim 1, wherein:

The phase change thermal storage material as a room temperature solid translucent density of 2000- 2300 kg · m- ^3, the melting temperature of 72- 80 ° C, a heat of fusion 290-300 kj · kg- ^1, 4 specific heat capacity. 5-5 kj · kg— ¹ · C— ¹ , thermal conductivity is 0. 5-1. 0 kj · nf ¹ · °(Τ ·

3. A heat storage element comprising a medium temperature heat storage material, comprising: a heat transferable shell and a heat transfer sheet, wherein the shell is a sealable cylindrical body, and the heat conductive sheet is provided therein The medium temperature phase change heat storage material is filled in the gap of the inner cavity of the casing.

A heat storage element comprising a medium temperature heat storage material according to claim 3, wherein the m-reinforced heat transfer sheet is a twist-like structure made of a metal sheet.

The heat storage element comprising a medium temperature heat storage material according to claim 3 or 4, wherein the housing is a 'cylindrical housing, and at least one asymmetric heat dissipation guide ring is disposed thereon.

6. A heating device comprising a heat storage element, comprising a casing, characterized in that - the casing is provided with a heat insulating layer, the inner cavity of which is arranged with heat storage elements distributed in m rows and n columns, upper portion a heat exchange coil is arranged, and a heating distributor and a heat distributor are respectively arranged at the top and the bottom, and the inlet and the outlet of the water supply system are connected at both ends of the coil, and the heat source is externally connected to the heat distributor, and the heat is supplied. The front end of the distributor is placed outside the box as the inlet and outlet for heating and heating respectively; in the upper and lower parts of the box, a temperature measuring probe is arranged, and a temperature sensor is arranged inside the probe, and the wire and time temperature controller are passed through Electrical connection; the gap in the tank is filled with water or other heat transfer medium.

Correction page (Article 91)