Heat storage and utilization equipment and method for gas waste heat

Abstract

The invention relates to a heat storage and utilization device and method for gas waste heat, the heat storage and utilization device comprises a first storage tank, a second storage tank, a rotary kiln type heat exchanger, a mixing reactor, a water supply device and a heat utilization heat exchanger, the rotary kiln type heat exchanger comprises a rotatable kiln barrel and a driving mechanism for driving the kiln barrel to rotate; a heat exchange reaction space is formed in the kiln barrel, a feeding port and a gas inlet are formed in one end of the rotary kiln type heat exchanger in the axial direction of the kiln barrel, a discharging port and a gas outlet are formed in the other side of the rotary kiln type heat exchanger, the first storage tank stores hydrated salt after water absorption reaction and is connected with the feeding port of the rotary kiln type heat exchanger, the kiln barrel is obliquely arranged, and the second storage tank is connected with the discharging port of the rotary kiln type heat exchanger. The side where the feeding port is located is higher than the side where the discharging port is located, the discharging port is connected with the second storage tank, the second storage tank is connected with the mixing reactor, the water supply device is connected with the mixing reactor, the mixing reactor is connected with the heat utilization heat exchanger, and the heat utilization heat exchanger is connected with the first storage tank.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal energy storage, and in particular to a heat storage and utilization device and method for gas waste heat. Background Art

[0002] The gas-steam combined cycle has the advantages of high thermal efficiency, low cost, low pollution, small footprint and flexible operation and adjustment, and has attracted the attention and implementation of countries around the world. The waste heat boiler is one of the three main equipment in the combined cycle power plant. It plays a connecting role between the gas turbine and the steam turbine, and its exhaust temperature is about 70-100℃. Generally speaking, the exhaust loss can reach 3%-8% of the overall heat loss of the waste heat boiler, which is the main loss affecting the thermal efficiency of the waste heat boiler. Unlike power plant boilers, the exhaust temperature of the waste heat boiler in the gas turbine steam combined cycle system is greatly affected by the ambient temperature, and the difference between the exhaust temperature in winter and summer is close to 30-40℃. Therefore, seasonal changes not only cause fluctuations in the performance of heavy-duty gas turbines, but also significantly affect the recovery potential of the waste heat of the waste heat boiler flue gas.

[0003] Whether it can be consumed on site is a prerequisite for the recovery and utilization of low-grade waste heat. Therefore, the waste heat of power plant boiler flue gas is mostly used to heat boiler feed water or preheat air. However, the exhaust temperature of waste heat boilers in winter is relatively low (about 70°C) and does not have the value of waste heat recovery. Although the exhaust temperature of waste heat boilers is relatively high in summer (about 100°C), a large amount of waste heat can be recovered, but the temperature difference between the waste heat and the boiler feed water or air in summer is small, and the heat exchange efficiency is low, which makes it difficult to consume the recovered waste heat on site. If the waste heat of high-temperature flue gas in summer can be recovered and stored in winter, it can be used to heat boiler feed water or plant heating, thereby solving the problem of mismatch between supply and demand of flue gas waste heat.

[0004] Heat storage is a common method to solve the mismatch between waste heat recovery and utilization processes. Common methods include phase change heat storage (such as paraffin) and thermochemical heat storage (such as hydrated salt). Among them, the basic principle of phase change heat storage is to use the release and absorption of latent heat of phase change of materials to store heat. Although it has the characteristics of high heat storage density and small temperature change, it can only be used to alleviate the mismatch between energy supply and demand between day and night (such as solar thermal utilization system), and cannot achieve cross-seasonal heat storage. In contrast, thermochemical heat storage uses reversible reactions to convert high-temperature thermal energy into chemical energy and store it in the reaction medium. When it is needed, the chemical energy is reversed into thermal energy through a reverse thermochemical reaction and released. Compared with latent heat storage, thermochemical heat storage has the advantages of high heat storage density (about 5 times that of paraffin), long heat storage time, and small energy loss. For example, CaCl 2 6H 2 O can be dehydrated to generate CaCl by heating in the temperature range of 60-100℃ 2 ·2H 2 O, which absorbs about 1145 J / g of heat. Similarly, CaCl2 ·2H 2 O can absorb water in a humid environment to generate CaCl 2 6H 2 O, and raise the temperature to 50-60 ° C. Similar hydrated salts include MgCl 2 6H 2 O、MgSO 4 7H 2 O、SrBr 2 6H 2 O, etc. However, the parameters of dehydration / water absorption temperature and price of different hydrated salts vary greatly. Only the low-priced CaCl 2 6H 2 O and MgSO 4 7H 2 O is suitable for deep recovery and cross-seasonal utilization of waste heat from waste heat boiler flue gas. However, the thermal conductivity of hydrated salt is low and the mass transfer resistance is large, resulting in low water absorption and dehydration rates, which significantly affects the recovery and utilization efficiency of waste heat from flue gas. Therefore, it is urgent to invent a new technology that greatly improves the water absorption and dehydration rates of hydrated salt to achieve deep recovery and cross-seasonal utilization of waste heat from waste heat boiler flue gas. Summary of the invention

[0005] In view of the shortcomings of the prior art mentioned above, the technical problem to be solved by the present invention is to provide a heat storage and utilization device and method for gas waste heat, which can effectively improve the dehydration bite water absorption efficiency of hydrated salt, thereby improving the utilization efficiency of hot gas and realizing efficient and long-term utilization of heat.

[0006] To achieve the above-mentioned purpose, the present invention provides a heat storage and utilization device for waste heat of gas, comprising a first storage tank, a second storage tank, a rotary kiln heat exchanger, a mixing reactor, a water supply device and a heat utilization heat exchanger, wherein the rotary kiln heat exchanger comprises a rotatable kiln shell and a driving mechanism for driving the kiln shell to rotate, and a heat exchange reaction space is provided in the kiln shell, the rotary kiln heat exchanger is provided with a feed inlet and a gas inlet at one end of the kiln shell along the axial direction, and a discharge port and a gas outlet at the other side, the first storage tank stores hydrated salt after water absorption reaction, and is connected to the feed inlet of the rotary kiln heat exchanger, the kiln shell is inclined, and the side where the feed inlet is located is higher than the side where the discharge port is located, the discharge port is connected to the second storage tank, the second storage tank is connected to the mixing reactor, the water supply device is connected to the mixing reactor, the mixing reactor is connected to the heat utilization heat exchanger, and the heat utilization heat exchanger is connected to the first storage tank.

[0007] Furthermore, the rotary kiln heat exchanger also includes an inner cylinder arranged in the kiln cylinder, and the space between the kiln cylinder and the inner cylinder is a heat exchange reaction space.

[0008] Furthermore, the outer peripheral surface of the inner cylinder of the rotary kiln heat exchanger and the inner wall surface of the kiln cylinder are both provided with spoiler fins.

[0009] Furthermore, the kiln cylinder is axially provided with a fin ring group, each fin ring group includes a plurality of spoiler fins evenly arranged along the circumference of the kiln cylinder, and the inner cylinder is axially provided with a fin ring group, each fin ring group includes a plurality of spoiler fins evenly arranged along the circumference of the inner cylinder.

[0010] Furthermore, the inclination angle of the rotary kiln heat exchanger is 15 to 40 degrees.

[0011] Furthermore, it also includes an atomizer arranged in the mixing reactor, which is connected to the water supply device and is used to atomize the water provided by the water supply device and then send it to the mixing reactor.

[0012] Furthermore, the hydrated salt stored in the first storage tank is CaCl 2 6H 2 O.

[0013] Furthermore, the heat utilization heat exchanger is a moving bed heat exchanger.

[0014] Furthermore, the gas inlet of the rotary kiln type heat exchanger is connected to the waste heat boiler for the entry of flue gas from the waste heat boiler.

[0015] The present invention also provides a method for heat storage and utilization of gas waste heat, which is performed using the above-mentioned heat storage and utilization equipment, and comprises:

[0016] S1, endothermic dehydration reaction: the hydrated salt in the first storage tank enters the heat exchange reaction space of the rotary kiln heat exchanger, and the hot gas also enters the heat exchange reaction space. The kiln body rotates, and the hydrated salt absorbs heat to undergo a dehydration reaction. The dehydrated hydrated salt flows out from the discharge port and enters the second storage tank, and the cooled gas flows out from the gas outlet;

[0017] S2, mixed water absorption exothermic reaction: the water supply device delivers water to the mixing reactor, the hydrated salt in the second storage tank enters the mixing reactor, the mixing reactor mixes the hydrated salt with the hydrated salt, the hydrated salt absorbs water and generates heat, and the high-temperature mixed substance after the reaction enters the heat utilization heat exchanger;

[0018] S3. Heat utilization: The heat utilization heat exchanger is connected to the fluid medium, the high-temperature mixed material heats the fluid medium through heat exchange, and the fluid medium is sent to the utilization site; the hydrated salt after heat exchange returns to the first storage tank from the heat utilization heat exchanger.

[0019] As described above, the heat storage and utilization device and method according to the present invention have the following beneficial effects:

[0020] 1. In the endothermic dehydration stage, by setting an inclined rotary kiln heat exchanger, the endothermic dehydration efficiency of the hydrated salt can be greatly improved, and the problem of the hydrated salt sticking during the dehydration process can be avoided, and the hydrated salt can flow out smoothly; in the water absorption and heat release stage, by setting a mixing reactor, the water and the hydrated salt are fully mixed and the water absorption reaction is completed at the same time, the reaction rate and efficiency are improved, and the method of first reaction and then heat exchange can be adopted, which can effectively avoid the problems of particle agglomeration and compaction caused by the deliquescence of the hydrated salt after excessive water absorption. The present invention can effectively ensure continuous and stable operation and effectively improve the utilization rate of gas waste heat.

[0021] 2. By setting up an atomizer, water is atomized and then mixed with hydrated salt to produce a water absorption and exothermic reaction, which has the advantages of fast reaction rate, small footprint and low energy consumption.

[0022] 3. Using a moving bed heat exchanger as a heat utilization heat exchanger can improve the heat exchange reaction between the hydrated salt and the fluid medium after the water absorption and exothermic reaction, thereby improving the heat utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of the heat storage and utilization equipment of the present invention.

[0024] Figure 2 for Figure 1 Cross-sectional view of the rotary kiln heat exchanger at point A.

[0025] Figure 3 for Figure 1 Cross-sectional view of the rotary kiln heat exchanger at point B.

[0026] Description of Figure Numbers

[0027] 1 First storage tank

[0028] 2 Second storage tank

[0029] 3 Rotary kiln heat exchanger

[0030] 31 Kiln Shell

[0031] 32 Inner tube

[0032] 33 Feeding port

[0033] 34 Gas inlet

[0034] 35 Discharge port

[0035] 36 Gas outlet

[0036] 37 spoiler fins

[0037] 38 Motor

[0038] 4 Mixing reactor

[0039] 5 Heat utilization heat exchanger

[0040] 6 Water supply device

[0041] 7 Atomizer

[0042] 8 Heat utilization medium device

[0043] 9 Waste Heat Boiler DETAILED DESCRIPTION

[0044] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0045] It should be noted that the structures, proportions, sizes, etc. drawn in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and so on quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0046] See also Figures 1 to 3 The present invention provides a heat storage and utilization device for waste heat of gas, comprising a first storage tank 1, a second storage tank 2, a rotary kiln heat exchanger 3, a mixing reactor 4, a water supply device 6 and a heat utilization heat exchanger 5, wherein the rotary kiln heat exchanger 3 comprises a rotatable kiln barrel 31 and a driving mechanism for driving the kiln barrel 31 to rotate, and the kiln barrel 31 has a heat exchange reaction space, and the rotary kiln heat exchanger 3 is provided with a feed inlet 33 and a gas inlet 34 at one end of the kiln barrel 31 along the axial direction, and a discharge port 35 and a gas discharge port 36 at the other side. The outlet 36, the first storage tank 1 stores the hydrated salt after the water absorption reaction, and is connected to the feed port 33 of the rotary kiln heat exchanger 3, the gas inlet 34 is used for the entry of the hot gas to be treated, the kiln shell 31 is inclined, and the side where the feed port 33 is located is higher than the side where the discharge port 35 is located, the discharge port 35 is connected to the second storage tank 2, the second storage tank 2 is connected to the mixing reactor 4, the water supply device 6 is connected to the mixing reactor 4, the mixing reactor 4 is connected to the heat utilization heat exchanger 5, and the heat utilization heat exchanger 5 is connected to the first storage tank 1.

[0047] The main working principle of the heat storage and utilization equipment involved in the present invention is: Figure 1The first storage tank 1 stores a hydrated salt after a water absorption reaction. The hydrated salt releases a large amount of heat during the water absorption reaction, and the obtained product undergoes a dehydration reaction during the heat absorption. Preferably, the hydrated salt is CaCl 2 6H 2 O, or MgSO 4 7H 2 In the present application, the hot gas refers to a gas with corresponding heat and temperature, which can heat the hydrated salt and cause a dehydration reaction, for example, it can be the flue gas generated by the waste heat boiler 9. The hydrated salt in the first storage tank 1 is CaCl 2 6H 2 O as an example, it exists in the form of fine particles of appropriate particle size, enters the heat exchange reaction space in the kiln shell 31 through the feed port, and at the same time, the hot gas enters the heat exchange reaction space from the gas inlet 34. The kiln shell 31 of the rotary kiln heat exchanger is driven by the driving mechanism to rotate at a certain speed, and the kiln shell 31 is tilted, so the hydrated salt will produce a composite motion in the heat exchange reaction space, rolling in the circumferential direction and moving from the high end to the low end in the axial direction, ensuring that the hydrated salt can move smoothly and flow out. CaCl 2 6H 2 O is fully contacted and mixed with the hot gas in the heat exchange reaction space, and the heat exchange between the two is sufficient. 2 6H 2 O absorbs heat and dehydrates to generate CaCl during the heat exchange process. 2 ·2H 2 O and water vapor, after heat exchange, CaCl 2 ·2H 2 O solid comes out from the discharge port 35 and enters the second storage tank 2, and the cooled gas comes out from the gas outlet 36. The heat of the treated hot gas is stored in the CaCl 2 ·2H 2 O, CaCl 2 ·2H 2 O can be stored in the second storage tank 2 for a long time to achieve cross-season utilization. This process can be used to recover the heat of the flue gas generated by the waste heat boiler 9 in summer. When heat is needed, especially in winter, the water supply device 6 delivers water to the mixing reactor 4, and the hydrated salt CaCl in the second storage tank 2 2 ·2H 2 O enters the mixing reactor 4, which combines water with the hydrated salt CaCl 2 ·2H 2 O is fully mixed and reacted in the mixing reactor 4 to produce CaCl 2 6H 2O, and releases a large amount of heat energy. The mixture after the reaction enters the heat utilization heat exchanger 5 from the mixing reactor 4, and exchanges heat with the fluid medium connected to the heat utilization heat exchanger 5. The heat is transferred to the fluid medium, and the fluid medium can be transported to a place where heat is needed for utilization, wherein the fluid medium can be water, gas or other fluids.

[0048] The heat storage and utilization equipment of the present invention can make the hydrated salt fully mixed with the hot gas during the endothermic dehydration reaction and move smoothly, thereby improving the dehydration efficiency. In the hydrated salt water absorption and exothermic reaction, the hydrated salt and water are fully mixed through the mixing reactor 4 to improve the efficiency of absorbing and releasing hot water, thereby improving the utilization efficiency of the heat of the hot gas. Through the long-term and stable storage of the hydrated salt, the efficient and long-term utilization of heat is achieved.

[0049] See also Figures 1 to 3 The present invention is further described below with a specific embodiment:

[0050] In this embodiment, see Figure 1 , Figure 2 and Figure 3 As a preferred design, the rotary kiln heat exchanger 3 further includes an inner cylinder 32 disposed in the kiln barrel 31. The inner cylinder 32 is preferably cylindrical and coaxially disposed with the kiln barrel 31. The space between the kiln barrel 31 and the inner cylinder 32 is a heat exchange reaction space. The kiln barrel 31 can rotate relative to the inner cylinder 32. Preferably, the inner cylinder 32 can rotate in the direction opposite to the rotation direction of the kiln barrel 31, so as to enhance the movement of the hydrated salt in the heat exchange reaction space. In addition, turbulent fins 37 are provided on the outer circumferential surface of the inner cylinder 32 and the inner wall surface of the kiln barrel 31. The kiln barrel 31 is provided with a fin ring group in the axial direction. Each fin ring group includes a plurality of turbulent fins 37 uniformly arranged along the circumference of the kiln barrel 31. Similarly, the inner cylinder 32 is provided with a fin ring group in the axial direction. Each fin ring group includes a plurality of turbulent fins 37 uniformly arranged along the circumference of the inner cylinder 32. The fin ring group on the kiln barrel 31 and the fin ring group on the inner cylinder 32 are staggered in the axial direction. In the above manner, during the rotation of the rotary kiln heat exchanger 3, the turbulent fins 37 are used to disturb the hydrated salt and the gas, so that the two are in more complete contact, and the problem of poor flow of the hydrated salt due to large mass transfer resistance can be better prevented.

[0051] In this embodiment, see Figure 1As a preferred design, the rotary kiln heat exchanger 3 has an inclination angle of 15 to 40 degrees, and the feed port 33, gas inlet 34, discharge port 35 and gas outlet 36 are all arranged at the two ends of the kiln barrel 31, so as to increase the contact time between the hot gas and the hydrated salt. The driving mechanism includes a motor 38, which can be connected to the kiln barrel 31 through an existing suitable intermediate transmission mechanism to drive the kiln barrel 31 to rotate, and can also be connected to the inner barrel 32 through a suitable intermediate transmission mechanism to drive the inner barrel 32 to rotate.

[0052] In this embodiment, see Figure 1 As a preferred design, it also includes an atomizer 7 disposed in the mixing reactor 4. The atomizer 7 is connected to the water supply device 6 and is used to atomize the water supplied by the water supply device 6 and transport it to the mixing reactor 4. The atomizer 7 preferably atomizes the water into micron-sized water droplets, so that the water is fully mixed with the hydrated salt under the action of the mixing reactor 4 to complete the water absorption reaction, which has the advantages of fast reaction rate, small device footprint and low energy consumption. In the present invention, the mixing reactor 4 can adopt an existing suitable structure, and the mixing principle is similar to that of a traditional gas-liquid or liquid-liquid mixer, and the mixing is achieved through a spiral flow channel under the action of a driving force (such as the gravity of the hydrated salt).

[0053] In this embodiment, see Figure 1As a preferred design, the heat utilization medium device 8 is connected to the heat utilization heat exchanger 5, and is used to provide a fluid medium to the heat utilization heat exchanger 5, wherein the fluid medium is water, or other liquids or gases, and then the heated fluid medium is transported to the plant area for heating, or it can be supplied to the waste heat boiler 9 for use. The heat utilization heat exchanger 5 is a moving bed heat exchanger, which is connected to the lower end of the mixing reactor 4. After the hydrated salt in the mixing reactor 4 reacts with water, it falls to the top of the moving bed heat exchanger. In the moving bed heat exchanger, as the heat exchange process proceeds, the hydrated salt solid particles gradually move downward, and finally are discharged from the bottom, and then transported and enter the first storage tank 1. Since the mixture of gas, water vapor and solid particles enters the moving bed heat exchanger in the mixing reactor 4, during the heat exchange process, the cold fluid medium enters from one end of the moving bed heat exchanger, exchanges heat with the heat exchange tube bundle and the solid particle bed in the moving bed heat exchanger, and absorbs heat from the solid particles and the heat exchange tube. Therefore, the hydrated salt solid particles also exchange heat with the fluid medium during the movement process, which plays a role in storing and transferring heat and improving the heat exchange efficiency. Compared with the traditional scheme of reacting while exchanging heat and finally recovering hot air, the scheme of first reacting and then exchanging heat is adopted in this embodiment, and finally hot water that is more convenient to use is obtained. The heat exchange process is carried out in the moving bed heat exchanger, which can effectively avoid the problems of particle agglomeration and hardening caused by the deliquescence of the hydrated salt after absorbing too much water, ensure the continuous and stable operation of the system, and effectively improve the utilization rate of waste heat. In other embodiments, the heat utilization heat exchanger 5 can also adopt other suitable existing heat exchangers that can achieve smooth heat exchange.

[0054] In the present invention, the transfer of hydrated salt particles between the first storage tank 1 and the rotary kiln heat exchanger 3, between the rotary kiln heat exchanger 3 and the second storage tank 2, between the second storage tank 2 and the mixing reactor 4, and between the heat utilization heat exchanger 5 and the first storage tank 1 can be achieved by setting a conveying mechanism. The conveying method can adopt an existing appropriate method. For example, a conveyor belt can be set to achieve the conveyance and transfer of hydrated salt particles from one device to another, and a sealing protective cover can be set during the transfer process; for example, the conveyance and transfer can be carried out by setting a pipeline, and some places can be rotated by gravity feeding, and a fan can also be set to blow. These existing conveying and transfer methods of granular objects are common in factory workshops, so they are not described in detail.

[0055] In this embodiment, see Figure 1 As a preferred design, the gas inlet 34 of the rotary kiln heat exchanger 3 is connected to the waste heat boiler 9 through a pipeline for the entry of flue gas generated by the waste heat boiler 9. The heat storage and utilization equipment can store the heat of the flue gas of the waste heat boiler 9 in summer and release it for utilization in winter. The heat storage and utilization equipment can also be used for heat storage and utilization of other types of heat-containing gases in industrial workshops.

[0056] The present invention also provides a method for heat storage and utilization of gas waste heat, which is performed using the above-mentioned heat storage and utilization equipment, and comprises:

[0057] S1, endothermic dehydration reaction: the hydrated salt (CaCl 2 6H 2 O) enters the heat exchange reaction space of the rotary kiln heat exchanger 3, and the hot gas also enters the heat exchange reaction space. The kiln shell 31 rotates, and the hydrated salt absorbs heat to undergo a dehydration reaction. The dehydrated hydrated salt (CaCl 2 ·2H 2 O) goes out from the discharge port 35 and enters the second storage tank 2, and the cooled gas goes out from the gas outlet 36. Hydrated salt (CaCl 2 ·2H 2 O) can be stored in the second storage tank 2 for a long time and used when needed.

[0058] S2, mixed water absorption exothermic reaction: the water supply device 6 delivers water to the mixing reactor 4, the water enters the mixing reactor 4 after being atomized, and the hydrated salt (CaCl 2 ·2H 2 O) enters the mixing reactor 4, which converts the hydrated salt (CaCl 2 ·2H 2 O) is mixed with hydrated salt, which absorbs water and generates heat to obtain hydrated salt (CaCl 2 6H 2 O), the high temperature mixed material after the reaction enters the heat utilization heat exchanger 5;

[0059] S3. Heat utilization: The heat utilization heat exchanger 5 is connected to the fluid medium, and the high-temperature mixed material heats the fluid medium through heat exchange, and the fluid medium is transported to the utilization site; the hydrated salt (CaCl 2 ·2H 2 O) returns to the first storage tank 1 from the heat utilization heat exchanger 5 for recycling.

[0060] As can be seen from the above, the heat storage and utilization equipment and method of the present invention have the following beneficial effects:

[0061] 1. In the endothermic dehydration stage, by setting an inclined rotary kiln heat exchanger 3, the endothermic dehydration efficiency of the hydrated salt can be greatly improved, and the problems of adhesion of the hydrated salt during the dehydration process can be avoided, and the hydrated salt can flow out smoothly; in the water absorption and heat release stage, by setting a mixing reactor 4, water and the hydrated salt are fully mixed while completing the water absorption reaction, thereby improving the reaction rate and efficiency. In addition, the method of first reaction and then heat exchange can effectively avoid the problems of particle agglomeration and compaction caused by the deliquescence of the hydrated salt after excessive water absorption. The present invention can effectively ensure continuous and stable operation and effectively improve the utilization rate of gas waste heat.

[0062] 2. By setting up the atomizer 7, water is atomized and then mixed with the hydrated salt to produce a water absorption and exothermic reaction, which has the advantages of fast reaction rate, small device footprint and low energy consumption.

[0063] 3. Using a moving bed heat exchanger as a heat utilization heat exchanger 5 can improve the heat exchange reaction between the hydrated salt and the fluid medium after the water absorption and exothermic reaction, thereby improving the heat utilization efficiency.

[0064] In summary, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0065] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A heat storage and utilization device for gas waste heat, characterized in that: The invention comprises a first storage tank (1), a second storage tank (2), a rotary kiln heat exchanger (3), a mixing reactor (4), a water supply device (6) and a heat utilization heat exchanger (5), wherein the rotary kiln heat exchanger (3) comprises a rotatable kiln shell (31) and a driving mechanism for driving the kiln shell (31) to rotate, and a heat exchange reaction space is provided in the kiln shell (31), and the rotary kiln heat exchanger (3) is provided with a material inlet (33) and a gas inlet (34) at one end of the kiln shell (31) along the axial direction, and a material outlet (35) and a gas outlet (36) at the other side, The first storage tank (1) stores hydrated salt after the water absorption reaction and is connected to the feed port (33) of the rotary kiln heat exchanger (3). The kiln shell (31) is tilted, and the side where the feed port (33) is located is higher than the side where the discharge port (35) is located. The discharge port (35) is connected to the second storage tank (2), the second storage tank (2) is connected to the mixing reactor (4), the water supply device (6) is connected to the mixing reactor (4), the mixing reactor (4) is connected to the heat utilization heat exchanger (5), and the heat utilization heat exchanger (5) is connected to the first storage tank (1).

2. The heat storage and utilization device according to claim 1, characterized in that: The rotary kiln heat exchanger (3) further comprises an inner cylinder (32) arranged in the kiln cylinder (31), and the space between the kiln cylinder (31) and the inner cylinder (32) is a heat exchange reaction space.

3. The heat storage and utilization device according to claim 2, characterized in that: The outer peripheral surface of the inner cylinder (32) of the rotary kiln heat exchanger (3) and the inner wall surface of the kiln cylinder (31) are both provided with flow-turbulating fins (37).

4. The heat storage and utilization device according to claim 3, characterized in that: The kiln cylinder (31) is provided with a fin ring group along the axial direction, and each fin ring group includes a plurality of turbulent fins (37) evenly arranged along the circumference of the kiln cylinder (31); the inner cylinder (32) is provided with a fin ring group along the axial direction, and each fin ring group includes a plurality of turbulent fins (37) evenly arranged along the circumference of the inner cylinder (32).

5. The heat storage and utilization device according to claim 1, characterized in that: The inclination angle of the rotary kiln type heat exchanger (3) is 15 to 40 degrees.

6. The heat storage and utilization device according to claim 1, characterized in that: It also includes an atomizer (7) disposed in the mixing reactor (4), wherein the atomizer (7) is connected to the water supply device (6) and is used to atomize the water supplied by the water supply device (6) and then deliver the water to the mixing reactor (4).

7. The heat storage and utilization device according to claim 1, characterized in that: The hydrated salt stored in the first storage tank (1) is CaCl2·6H2O.

8. The heat storage and utilization device according to claim 1, characterized in that: The heat utilization heat exchanger (5) is a moving bed heat exchanger.

9. The heat storage and utilization device according to claim 1, characterized in that: The gas inlet (34) of the rotary kiln type heat exchanger (3) is connected to the waste heat boiler for the entry of flue gas from the waste heat boiler.

10. A method for storing and utilizing waste heat from gas, characterized in that: The heat storage and utilization device according to claim 1 is used, comprising: S1, endothermic dehydration reaction: the hydrated salt in the first storage tank (1) enters the heat exchange reaction space of the rotary kiln heat exchanger (3), and the hot gas also enters the heat exchange reaction space. The kiln shell (31) rotates, and the hydrated salt absorbs heat to undergo a dehydration reaction. The dehydrated hydrated salt exits from the discharge port (35) and enters the second storage tank (2), and the gas after cooling exits from the gas outlet (36); S2, mixed water absorption exothermic reaction: the water supply device (6) delivers water to the mixing reactor (4), the hydrated salt in the second storage tank (2) enters the mixing reactor (4), the mixing reactor (4) mixes the hydrated salt with the hydrated salt, the hydrated salt absorbs water and generates heat, and the high-temperature mixed substance after the reaction enters the heat utilization heat exchanger (5); S3. Heat utilization: The heat utilization heat exchanger (5) is connected to the fluid medium, and the high-temperature mixed material heats the fluid medium through heat exchange, and the fluid medium is sent to the utilization site; the hydrated salt after heat exchange returns from the heat utilization heat exchanger (5) to the first storage tank (1).

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