A molten salt heat transfer, heat storage, and heat exchange integrated green alcohol synthesis device

Abstract

The present invention is a green alcohol synthesis device that integrates molten salt heat transfer, heat storage, and heat exchange. By using molten salt with a wide temperature range, high specific heat capacity, and normal pressure as a heat transfer medium, and by setting up a heat storage medium circulation system, the reaction heat generated in the inner cavity is continuously transferred to the outer cavity to heat the raw gas. The heat generated in the inner cavity is stored in the molten salt medium in the form of sensible heat, so that the green alcohol synthesis device can realize the integration of heat transfer, heat storage, and heat exchange functions. It can effectively solve the problems of low temperature of raw gas entering the synthesis device in the existing synthesis methanol technology, a large number of coordinating equipment, and large space occupation. By using molten salt with high specific heat capacity to fully absorb the high heat generated inside the synthesis device, the main reaction inside the synthesis device is maintained in stable operation, avoiding the phenomenon of converting carbon monoxide into carbon dioxide and removing carbon dioxide to maintain the internal temperature of the synthesis device in the existing technology, avoiding carbon dioxide emissions, reducing the loss of raw gas, and thus improving the methanol yield.

Description

Technical Field

[0001] The present invention belongs to the technical field of green methanol synthesis, and in particular relates to a green methanol synthesis device integrating molten salt heat transfer, heat storage and heat exchange. Background Art

[0002] Methanol, the simplest saturated monohydric alcohol, is an important chemical raw material and clean fuel, applicable in industries such as organic chemical raw materials, alternative energy, and pharmaceuticals. Methanol can be obtained through three methods: methyl chloride hydrolysis, methane oxidation, and the feed gas method. The first two methods are not widely used in industry due to limitations in methanol production. Currently, the feed gas method is commonly used in industry to produce methanol. Feed gas primarily consists of carbon monoxide, hydrogen, and carbon dioxide. Due to the development and application of methanol fuel, demand for methanol is increasing both domestically and internationally. Furthermore, producing methanol from feed gas provides a new approach to carbon dioxide capture and disposal, actively responding to the country's "dual carbon" policy. As a result, the feed gas method for producing methanol is gradually gaining attention.

[0003] The main deficiencies in the technology of synthesizing methanol from raw gas are as follows: (1) the existing raw gas needs to be heated by a separate heater or preheated by a heat exchanger before entering the synthesis unit. The temperature of the preheated raw gas entering the synthesis unit is lower than the temperature of the catalyst bed inside the synthesis unit. The lower raw gas temperature leads to an increase in side reactions inside the synthesis unit. In addition, this method of heating the raw gas has certain requirements for land occupation and high investment costs; (2) under the specific production conditions of green alcohol, the fixed tube plate heat exchange tube bundle built into the synthesis unit has a high-temperature heat alternating load due to reaction heat release, which can cause the reaction to occur. It is easy to cause the heat exchange tube to separate from the fixed tube sheet and damage the heat exchange tube bundle. If the heat exchange tube bundle is damaged, the soft water in the heat exchange tube will leak into the synthesis device, causing catalyst failure and water instantaneous vaporization overpressure. Major safety accidents; (3) Under the specific reaction temperature conditions of green alcohol, the steam pressure corresponding to the saturated steam temperature in the drum is low, resulting in low steam quality, limited secondary use of recovered heat, and inability to generate superheated steam. The high energy and low use situation seriously does not comply with energy utilization rules; (4) Since the process of synthesizing methanol from raw gas is an exothermic process, The existing methanol synthesis device uses high-pressure water cooling to control the reaction temperature inside the synthesis device by controlling the pressure of the external steam drum. This temperature control method requires the installation of a steam drum and a matching dosing device, which has certain limitations for users with small sites and high equipment investment costs. (5) The existing synthesis device uses water cooling to transfer heat, which requires a large amount of water resources for heat exchange. Since tap water will corrode the components inside the synthesis device, softened water or purified water needs to be used. A separate water production device needs to be set up, resulting in increased water production costs and increased operating costs. (6) The same molar oxygen The heat released by synthesizing methanol from carbon monoxide and carbon dioxide is nearly twice as great, with the former releasing much more heat than the latter. When the raw gas contains a high amount of carbon monoxide, the strong reaction heat generated rapidly inside the synthesis unit cannot be removed, resulting in overheating inside the synthesis unit and deactivation of the catalyst, which is not conducive to reaction operation control. To avoid this phenomenon, the existing treatment method converts carbon monoxide into carbon dioxide and hydrogen by adding water vapor, and then removes the excess carbon dioxide. This treatment method reduces the amount of carbon elements participating in the reaction, resulting in a lower content of synthesized methanol and carbon dioxide emissions, and requires a separate conversion equipment.

[0004] In view of this, the present invention proposes a molten salt heat transfer, heat storage, and heat exchange integrated green alcohol synthesis device. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the problem to be solved by the present invention is to provide a molten salt heat transfer, heat storage, and heat exchange integrated green alcohol synthesis device. The synthesis device adopts a molten salt with a wide temperature range, high specific heat capacity, and normal pressure as a heat transfer medium. By setting up a heat storage medium circulation system, the reaction heat generated in the inner cavity can be continuously transferred to the outer cavity to heat the raw gas. The heat generated in the inner cavity is stored in the molten salt medium in the form of sensible heat, so that the green alcohol synthesis device can realize the integration of heat transfer, heat storage, and heat exchange functions. It can effectively solve the problems of low temperature of raw gas entering the synthesis device, large number of cooperating equipment, and large space occupation in the existing synthesis methanol technology; by using high specific heat capacity molten salt to fully absorb the high heat generated inside the synthesis device, the main reaction inside the synthesis device is maintained in stable operation, avoiding the phenomenon of converting carbon monoxide into carbon dioxide and removing carbon dioxide in order to maintain the internal temperature of the synthesis device in the existing technology, avoiding carbon dioxide emissions, reducing the loss of raw gas, and thus improving the methanol yield.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A green alcohol synthesis device integrating molten salt heat transfer, heat storage, and heat exchange comprises a reaction shell, and a heat exchange component, a cavity, and a raw gas distribution component arranged inside the reaction shell. The device is characterized in that the reaction shell comprises, from top to bottom, a floating head, a reaction cylinder, and a lower head; the floating head is provided with a raw gas reaction outlet and a catalyst inlet; the lower head is provided with a catalyst discharge port and a heat storage medium outlet; the reaction cylinder is formed as a whole by an inner cylinder and an outer cylinder;

[0008] The cavity includes an inner cavity formed by the inner wall of the inner cylinder and the inner wall of the floating head, and an outer cavity formed by the outer wall of the inner cylinder, the inner wall of the outer cylinder and the inner wall of the lower head;

[0009] The heat exchange assembly includes a heat storage medium tube bundle located in the inner cavity and a raw gas tube bundle in the outer cavity;

[0010] The raw gas distribution component is located at the bottom of the inner cavity surrounded by the inner cylinder;

[0011] A heat storage medium inlet is provided on the inner cylinder, and the heat storage medium is located below the connection position between the inner cylinder and the floating head and above the outer cylinder;

[0012] A raw gas inlet is provided at the upper portion of the outer cylinder;

[0013] The raw gas pipe bundle is located inside the outer cavity and is arranged in a spirally coiled manner from top to bottom. The upper end is the starting end of the coil, which is connected to the raw gas inlet, and the lower end is the end of the coil, which is connected to the raw gas distribution assembly in the inner cylinder. Each ring of the raw gas pipe bundle is fixed to the inner wall of the outer cylinder and / or the outer wall of the inner cylinder by a support member.

[0014] The heat storage medium tube bundle is located in the inner cavity of the inner cylinder and is arranged in a spiral shape along the middle axis of the reaction shell from top to bottom. The upper end is the starting end of the coil and is connected to the heat storage medium inlet. The lower end is the end of the coil and passes through the inner cylinder to communicate with the outer cavity. Each ring of the heat storage medium tube bundle is fixed to the inner wall of the inner cylinder by a support member.

[0015] The heat storage medium outlet is connected to the circulation pump inlet through an external pipeline, and the circulation pump outlet is connected to the heat storage medium inlet through an external pipeline; the outer cavity and the interior of the heat storage medium tube bundle are filled with molten salt heat storage medium.

[0016] Furthermore, a flange is welded to the lower end of the floating head, and a counter-flange is welded to the upper end of the inner cylinder body which matches the flange at the lower end of the floating head. The floating head flange and the counter-flange of the inner cylinder body are connected and fixed to the floating head and the inner cylinder body by bolts, nuts and gaskets, which is a detachable connection; the outer cylinder body is welded and fixed and covered on the outer layer of the inner cylinder body, and the upper edge of the outer cylinder body is 30-50 cm away from the flange end face of the inner cylinder body; the lower end of the outer cylinder body is rigidly connected to the lower head by welding; the inner cylinder body is in the form of a cylinder with a closed lower end and an open upper end.

[0017] Furthermore, the raw gas distribution assembly is composed of a raw gas elbow, a raw gas straight pipe and a raw gas distribution head welded together, and the raw gas elbow is connected to the lower coil end of the raw gas pipe bundle; preferably, the raw gas distribution head adopts a spherical mesh structure.

[0018] Furthermore, at the same height, the support members are evenly distributed along the circumferential direction, and the support members have a horizontal support surface, and the winding coil is fixed to the horizontal support surface by a semicircular clamp; the length of the support member in the outer cavity is the same as the width of the outer cavity or extends from the outer wall of the inner cylinder to the outside of the pipe of the winding coil of the raw gas pipe bundle, and the length of the support member in the inner cavity extends from the inner wall of the inner cylinder to the inside of the pipe of the winding coil of the heat storage medium pipe bundle. The support member can meet the function of supporting the raw gas pipe bundle / heat storage medium pipe bundle.

[0019] Furthermore, the straight pipe section of the catalyst unloading port passes through the lower head and the bottom end of the inner cylinder in sequence and is connected to the inner cavity. The straight pipe section of the catalyst unloading port is connected to the contact points of the lower head and the bottom end of the inner cylinder by welding; the catalyst unloading port is sealed by a blind plate during the use of the synthesis device.

[0020] The catalyst is filled in the inner cavity formed by the inner wall of the inner cylinder and the inner wall of the floating head, and the filling coefficient reaches 80%.

[0021] Furthermore, oblique supports are provided in the outer cavity to provide support for the inner cylinder. The oblique supports are evenly arranged around the outer surface of the inner cylinder. The specific number of oblique supports is set according to the total weight of the inner cylinder and the object carried inside the inner cylinder.

[0022] The oblique support includes a lower pad, an upper pad, and an oblique support rod. The lower pad is made into a pad with the same curvature as the inner surface of the lower head, and the lower pad is fully welded to the lower head. The upper pad is made into a pad with the same curvature as the outer surface of the inner cylinder, and the upper pad is fully welded to the inner cylinder. The two ends of the oblique support rod are respectively welded to the upper pad and the lower pad; preferably, the angle between the oblique support and the outer surface of the inner cylinder is between 30-45°.

[0023] Furthermore, the bottom of the inner cylinder is configured as a dome structure to facilitate catalyst unloading.

[0024] The heat storage medium is a binary salt or a ternary salt molten salt, and the selected molten salt should meet the properties of a wide temperature range, high specific heat capacity, good fluidity, low melting point and high boiling point.

[0025] Furthermore, the spacing between upper and lower adjacent pipes in the same type of raw gas pipe bundle and heat storage medium pipe bundle is 3-6 cm.

[0026] Furthermore, multiple thermocouples are arranged from top to bottom along the inner surface of the inner cylinder 6 for real-time monitoring of the internal temperature of the inner cylinder; the circulation pump 19 is a high-temperature resistant variable-frequency molten salt pump, which controls the frequency of the circulation pump 19 by receiving the temperature signal emitted by the multiple thermocouples, thereby controlling the flow rate of the molten salt in the heat storage medium tube bundle 11 and adjusting the heat transfer rate.

[0027] Furthermore, the heat storage medium inlet is arranged on the side wall of the outer surface of the inner cylinder, between the upper end edge of the outer cylinder and the flange end surface of the inner cylinder, and is located at the upper right end of the reaction shell. The heat storage medium inlet is welded to the wall of the inner cylinder.

[0028] Furthermore, the raw gas inlet is arranged on the side wall of the outer surface of the outer cylinder, located at the upper right end of the outer cylinder, and directly below the heat storage medium inlet. The raw gas inlet is welded to the wall of the outer cylinder.

[0029] Furthermore, the heat storage medium outlet is located on the lower right side of the outer surface of the lower head, passes through the lower head and is fixed to the lower head by welding. The heat storage medium outlet is located directly below the raw gas inlet and the heat storage medium inlet.

[0030] Furthermore, the catalyst feed port is located on the right side of the floating head at a 45° angle, the catalyst feed port is connected to the contact position of the floating head by welding, and the catalyst feed port is blocked by a blind plate during use of the synthesis device.

[0031] Furthermore, the catalyst discharge port and the raw gas reaction outlet are installed on the middle shaft of the reaction shell.

[0032] Raw gas flows in the raw gas pipe bundle.

[0033] Furthermore, the heat storage medium tube bundle, the external cavity, the circulation pump, and the external pipeline together constitute a heat storage medium circulation system.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. The green alcohol synthesis device of the present invention integrates heat transfer, heat storage, and heat exchange. Compared with existing methanol synthesis devices, which require an external preheater or heater to preheat or heat the feed gas, the synthesis device of the present invention is provided with a preheating space consisting of an outer cavity and a heat storage medium circulation system. The heat storage medium absorbs the reaction heat of the inner cavity and is used to heat the feed gas in the outer cavity. The entire heating process occurs in an independent synthesis device, eliminating the need for an external preheater or heater. The green alcohol synthesis device of the present invention has a simple structure, reduces space occupation, and is more economical in cost, with a significant cost reduction of approximately 10%-20%.

[0036] 2. The heat transfer structure of the green alcohol synthesis device of the present invention is compared with the existing synthesis device. The existing synthesis device transfers heat through an internal fixed tube sheet heat exchange tube bundle. The tube bundle adopts the form of fixed straight tubes, and the straight tubes are filled with high-pressure water for heat transfer. In this heat transfer method, the pipes bear high pressure. The fixed straight tube form not only makes the pipes less capable of eliminating thermal stress, but also easily causes pipe cracking, causing leakage of high-pressure water inside the tube bundle, resulting in deactivation of the synthesis device catalyst. The leaked high-pressure water instantly vaporizes, causing overpressure in the synthesis device, thereby causing major safety accidents. The heat transfer and heat storage pipe fittings of the present invention use a heat storage medium tube bundle, which is spirally coiled. The heat storage medium in the tube bundle is at normal pressure. The pressure on each pipe in the tube bundle is small, and the rotating curvature can effectively eliminate thermal stress. This avoids the problem of easy cracking of the fixed tube sheet heat exchange tube bundle in the prior art and enhances the stability of the methanol synthesis device.

[0037] 3. The green alcohol synthesis device of the present invention adopts circulating molten salt filled inside the heat storage medium tube bundle to transfer heat from the inside of the synthesis device. No replenishment is required unless there are special circumstances. Compared with the existing synthesis device that transfers heat through high-pressure water, removing the reaction heat inside the synthesis device requires a large amount of water resources, which is restrictive for water-scarce areas. In order to avoid corrosion, the cooling water used for the equipment needs to use softened water or pure water, resulting in increased operating costs and equipment investment for methanol synthesis in the existing technology. The present invention is provided with a heat storage medium circulation system, and the heat storage medium is recycled in the synthesis device without replenishment. The present invention changes the traditional water phase change high-pressure heat transfer medium into a molten salt sensible heat and normal pressure heat transfer medium, and the vaporization temperature of the molten salt heat transfer medium is much higher than the maximum reaction temperature of the synthesis device, and there is no gasification phenomenon, which can effectively solve the internal leakage and water vaporization overpressure problems of the existing technology. Since the present invention adopts molten salt with high specific heat capacity as the heat storage medium, the dependence of the synthesis device on water resources can be eliminated, water production equipment can be eliminated, and investment costs, operating costs and construction period can be reduced.

[0038] 4. The green alcohol synthesis device of the present invention adopts a heat storage medium circulation system to achieve temperature control of the entire synthesis device, which is compared with the temperature control method of the existing methanol synthesis device. The existing technology mainly controls the final heat exchange temperature of the cooling water by controlling the pressure of the external steam drum, thereby controlling the reaction temperature inside the synthesis device; the present invention sets a normal pressure heat storage medium circulation system, and uses the heat storage medium to continuously transfer the heat of the inner cavity to the outer cavity. The heat of the heat storage medium in the outer cavity is used to heat the raw gas. The setting of the heat storage medium circulation system not only preheats the raw gas, but also meets the temperature control effect of the inner cavity. Compared with the existing technology, the temperature control method of the present invention adopts a normal pressure circulation form, which increases the safety of the system. The heat generated by the device itself is used to heat the raw gas. On the one hand, it reduces the input of external energy and can achieve self-generation and self-consumption of heat; on the other hand, it eliminates equipment such as the external steam drum and the supporting dosing device, reduces the equipment space, simplifies the methanol synthesis system, reduces investment costs, and shortens the construction period.

[0039] 5. Compared with the existing synthesis device, the green alcohol synthesis device of the present invention uses constant-pressure cooling water to transfer heat. When strong reaction heat is rapidly generated in the synthesis device, the heat absorbed by the cooling water under a given pressure is certain, and the existing synthesis device cannot quickly remove the heat generated inside. If the steam drum pressure is changed, the temperature of the saturated water will rise accordingly, resulting in the inability to control the temperature inside the synthesis device. The pressure bearing capacity of the pipeline is limited, and the ability of the existing synthesis device to cope with temperature increases is weak; while the present invention adopts molten salt with high thermal conductivity, high specific heat capacity and high vaporization point, and utilizes the sensible heat of molten salt to transfer heat and store heat at normal pressure. The upper limit of the molten salt temperature exceeds 565°C, and the heat rapidly generated inside the synthesis device can be stored in the molten salt medium in the form of sensible heat, and the heat can be quickly transferred to the outer cavity through circulation, thereby avoiding heat loss inside the synthesis device and ensuring the stable operation of the reaction inside the synthesis device.

[0040] 6. Compared with the existing synthesis device, when the carbon monoxide content in the raw gas is high, in order to avoid the temperature loss of the reaction inside the synthesis device and make it difficult to control, the existing methanol synthesis technology process requires the use of steam reforming to treat part of the carbon monoxide, converting the carbon monoxide into carbon dioxide and hydrogen, and then removing the carbon dioxide, and synthesizing methanol from the treated raw gas; however, the present invention adopts molten salt with high specific heat capacity and wide temperature range as the heat storage medium, which can effectively solve the problem that the raw gas cannot be directly introduced into the methanol synthesis device for reaction due to the high carbon monoxide content. The generated reaction heat can be stored in the molten salt medium. The molten salt inside the heat storage medium tube bundle of the present invention is at normal pressure and has the characteristics of low melting point, high boiling point, and wide temperature range, which is sufficient to absorb the reaction heat generated rapidly inside the synthesis device. Unlike the cooling water in the existing technology, which is restricted by the steam drum pressure and the pressure bearing capacity of the internal pipeline, it cannot bear too much heat. The present invention can eliminate the carbon monoxide conversion process in the existing methanol synthesis process, thereby reducing the equipment investment in the conversion process, shortening the investment payback period, and avoiding the emission of carbon dioxide in the existing methanol synthesis process, thereby improving the utilization rate of raw gas and increasing the methanol yield rate. The device has a high single-pass conversion rate.

[0041] 7. The molten salt in the heat storage medium tube bundle of the green alcohol synthesis device of the present invention flows from top to bottom, and the raw gas enters the inner cavity of the synthesis device from the raw gas distribution component and flows from bottom to top. This flow mode makes the heat exchange more sufficient and the heat absorption more complete; the reaction path of the raw gas along the direction of flow of the intermediate axis is long, and the raw gas is in full contact with the catalyst, so that the raw gas reaction is more sufficient and the single-pass conversion rate of the raw gas is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a schematic structural diagram of a green alcohol synthesis device integrating molten salt heat transfer, heat storage and heat exchange according to the present invention;

[0043] Figure 2This is an overall schematic diagram of a green alcohol synthesis device integrating molten salt heat transfer, heat storage and heat exchange according to the present invention;

[0044] Figure 3 It is a schematic diagram of the structure of the support member and the fixing member of the present invention;

[0045] Figure 4 Schematic diagram of the oblique support structure of the present invention;

[0046] In the figure, 1. reaction shell; 2. heat exchange component; 3. cavity; 4. raw gas distribution component; 5. floating head; 6. inner cylinder; 7. outer cylinder; 8. oblique support; 9. inner cavity; 10. outer cavity; 11. heat storage medium tube bundle; 12. raw gas tube bundle; 13. lower head; 14. catalyst inlet; 15. catalyst unloading port; 16. heat storage medium outlet; 17. heat storage medium inlet; 18. raw gas inlet; 19. circulating pump; 20. support; 21. semicircular clamp; 22. intermediate shaft; 23. reaction cylinder; 24. raw gas reaction outlet; 801. upper pad; 802. oblique support rod; 803. lower pad; 401. raw gas elbow; 402. raw gas straight pipe; 403. raw gas distribution head. DETAILED DESCRIPTION

[0047] The present invention is further described below in conjunction with the specific drawings, but the following embodiments are only preferred embodiments of the present invention and are not exhaustive. Based on the embodiments in the implementation manner, other embodiments obtained by those skilled in the art without making any creative work are all within the scope of protection of this patent.

[0048] The present invention provides a molten salt heat transfer, heat storage, heat exchange integrated green alcohol synthesis device (see Figure 1-4 ), the green alcohol synthesis device includes a reaction shell 1, and a heat exchange component 2, a cavity 3, and a raw gas distribution component 4 arranged inside the reaction shell; the reaction shell 1 includes a floating head 5, a reaction cylinder 23, and a lower head 13 from top to bottom; the floating head 5 is provided with a raw gas reaction outlet 24 and a catalyst inlet 14; the lower head 13 is provided with a catalyst discharge port 15 and a heat storage medium outlet 16; the reaction cylinder 23 is formed as a whole by an inner cylinder 6 and an outer cylinder 7; a raw gas inlet 18 is provided at the upper end of the outer cylinder 7;

[0049] The cavity 3 includes an inner cavity 9 formed by the inner wall of the inner cylinder 6 and the inner wall of the floating head 5, and an outer cavity 10 formed by the outer wall of the inner cylinder 6, the inner wall of the outer cylinder 7 and the inner wall of the lower head 13;

[0050] The outer cavity is provided with an oblique support 8 to provide support for the inner cylinder. There are four oblique supports evenly arranged around the outer surface of the inner cylinder. The specific number of oblique supports can be set according to the total weight of the inner cylinder and the object carried inside the inner cylinder.

[0051] The heat exchange assembly 2 includes a heat storage medium tube bundle 11 located in the inner cavity 9 and a raw gas tube bundle 12 located in the outer cavity 10;

[0052] The raw gas distribution assembly 4 is composed of a raw gas elbow 401, a raw gas straight pipe 402, and a raw gas distribution head 403 connected by welding, and is located at the bottom of the inner cavity 9 surrounded by the inner cylinder 6;

[0053] The lower end of the floating head 5 is welded with a flange, and the upper end of the inner cylinder 6 is welded with a counter-flange that matches the flange at the lower end of the floating head 5. The flange of the floating head 5 and the counter-flange of the inner cylinder 6 are connected and fixed to the floating head 5 and the inner cylinder 6 by bolts, nuts and gaskets, which are detachable connections; the outer cylinder 7 is welded and fixed and covered on the outer layer of the inner cylinder 6, and the upper end edge of the outer cylinder 7 is 40 cm away from the flange end face of the inner cylinder 6; the lower end of the outer cylinder 7 is rigidly connected to the lower head 13 by welding; the inner cylinder 6 is a cylindrical form with a closed lower end and an open upper end;

[0054] The direction from the middle shaft 22 to the outside is from inside to outside, and the direction pointing to the middle shaft 22 is from outside to inside.

[0055] The raw gas pipe bundle 12 is located inside the outer cavity 10 and is arranged in a spirally coiled form from top to bottom, with the upper end being the starting end of the coil and the lower end being the end of the coil; each annularly wound coil is provided with a support member 20, and the support member 20 is based on the outer surface of the inner cylinder 6 as the base, and four support members 20 are evenly arranged at the same height with the middle axis 22 of the reaction shell 1 as the axis. The angle between two adjacent support members 20 is 90°, and the length of the support member 20 in the radial direction from the middle axis 22 to the outside (close to the side of the outer cylinder 7) can be the same width as the outer cavity 10 or extend to the pipe of the raw gas pipe bundle 12. The support member 20 only needs to support the raw gas pipe bundle 12 until it reaches the outside of the channel. A semicircular clamp 21 is provided on the outside of the pipe of the raw gas pipe bundle 12. Both ends of the semicircular clamp 21 are threaded. The threaded end passes through the support member 20 and is fixedly connected to the support member 20 via a gasket and a nut. The raw gas pipe bundle 12 passes through the upper right end of the outer cylinder 7 and is connected to the raw gas inlet 18. The coil end of the raw gas pipe bundle 12 passes through the bottom of the inner cylinder 6, passes into the inner cavity 9 of the inner cylinder 6, and is connected to the raw gas distribution assembly 4 by welding.

[0056] The heat storage medium tube bundle 11 is located in the inner cavity 9 of the inner cylinder 6, and is arranged in a spiral shape along the middle axis 22 of the reaction shell 1 from top to bottom, with the upper end being the starting end of the coil and the lower end being the end of the coil; the fixing method of the heat storage medium tube bundle 11 adopts a fixing method similar to that of the raw gas tube bundle 12, and each ring of the heat storage medium pipeline is provided with a fixing member (not shown), and the fixing member (not shown) is based on the inner surface of the inner cylinder 6 and is evenly arranged at the same height with the middle axis 22 of the reaction shell 1 as the axis. The angle between two adjacent fixing members is 90°, and the fixing member points along the wall of the inner cylinder 6 in the radial direction of the middle axis 22 (away from the wall side of the inner cylinder 6). ) length, the fixing piece can be extended to the inner side of the pipe of the heat storage medium tube bundle 11, and the fixing piece can satisfy the function of supporting the heat storage medium tube bundle 11; a semicircular clamp 21 is provided on the outside of the pipe of the heat storage medium tube bundle 11, and both ends of the semicircular clamp 21 are provided with threads, and the threaded end passes through the fixing piece and is fixedly connected to the fixing piece via a gasket and a nut; the starting end of the coil of the heat storage medium tube bundle 11 is close to the flange surface at the upper end of the inner cylinder 6, passes through the wall surface of the inner cylinder 6 and is connected to the heat storage medium inlet 17; the end of the coil of the heat storage medium tube bundle 11 is connected to the outer cavity 10 from the wall surface of the inner cylinder 6 on the side close to the bottom of the inner cylinder 6;

[0057] The heat storage medium outlet 16 is connected to the inlet of a circulation pump 19 through an external pipeline, and the outlet of the circulation pump 19 is connected to the heat storage medium inlet 17 through an external pipeline.

[0058] Specifically, the outer cavity 10 and the heat storage medium tube bundle 11 are both filled with heat storage medium;

[0059] In this embodiment, the outer cavity 10 provides a carrying space for the heat storage medium. The heat storage medium inside the outer cavity 10 has two main functions: on the one hand, it absorbs heat transmitted from the wall of the inner cylinder 6; on the other hand, it transfers the heat absorbed from the inner cavity 9 to the feed gas, exchanging heat with the feed gas. The heat storage medium in the heat storage medium tube bundle 11 has two main functions: on the one hand, it absorbs the reaction heat of the inner cavity 9 and transfers it to the outer cavity 10 to ensure the reaction temperature of the inner cavity 9; on the other hand, it stores the strong reaction heat quickly generated by the inner cavity 9.

[0060] In this embodiment, the raw gas distribution assembly 4 is provided with a raw gas elbow 401 to effectively prevent the raw gas from flowing directly into the inner cavity 9, which may cause the catalyst to clog the raw gas pipeline. The raw gas distribution head 403 is installed at the end of the raw gas straight pipe 402 and has a spherical mesh structure. The spherical mesh structure makes its surface evenly stressed and not easily damaged.

[0061] In this embodiment, the raw gas tube bundle 12 and the heat storage medium tube bundle 11 are both made of seamless stainless steel pipes, and the materials of seamless stainless steel pipes include but are not limited to 316, 347, and 348; the inner cylinder 6, the outer cylinder 7, the lower head 13, and the floating head 5 can be made of Q345R or Q370R, but are not limited to the above materials. The reaction shell material is required to have high strength, high heat resistance, oxidation resistance, and easy welding.

[0062] In this embodiment, multiple thermocouples (not shown in the figure) are arranged from top to bottom along the inner surface of the inner cylinder 6 to monitor the internal temperature of the inner cylinder in real time.

[0063] Specifically, the circulation pump 19 is a high-temperature resistant variable-frequency molten salt pump, which controls the frequency of the circulation pump 19 by receiving the temperature signal emitted by the multi-point thermocouple, thereby controlling the flow rate of the molten salt in the heat storage medium tube bundle 11 and adjusting the heat transfer rate;

[0064] In this embodiment, when the raw gas contacts and reacts with the catalyst in the inner cavity 9, the multi-point thermocouples in the inner cavity 9 monitor the temperature changes in real time. When a sharp change in the temperature inside the synthesis device is detected, the multi-point thermocouples transmit the temperature signal to the circulation pump 19. After receiving the temperature signal, the circulation pump 19 increases the speed of the circulation pump, thereby increasing the circulation speed of the heat storage medium, further accelerating the removal of heat from the synthesis device, and providing protection for the safe operation of the synthesis device.

[0065] Furthermore, the inclined support 8 includes a lower pad 803, an upper pad 801, and an inclined support rod 802. The lower pad is made into a pad with the same curvature as the inner surface of the lower head, and the lower pad is fully welded to the lower head. The upper pad is made into a pad with the same curvature as the outer surface of the inner cylinder, and the upper pad is fully welded to the inner cylinder. The two ends of the inclined support rod are respectively welded to the upper pad and the lower pad. The angle between the inclined support and the outer surface of the inner cylinder is between 30-45°.

[0066] Furthermore, the heat storage medium inlet is arranged on the side wall of the outer surface of the inner cylinder, between the upper end edge of the outer cylinder and the flange end surface of the inner cylinder, and is located at the upper right end of the reaction shell. The heat storage medium inlet is welded to the wall of the inner cylinder.

[0067] Furthermore, the raw gas inlet is arranged on the side wall of the outer surface of the outer cylinder, located at the upper right end of the outer cylinder, and directly below the heat storage medium inlet. The raw gas inlet is welded to the wall of the outer cylinder.

[0068] Furthermore, the heat storage medium outlet is located on the lower right side of the outer surface of the lower head, passes through the lower head and is fixed to the lower head by welding. The heat storage medium outlet is located directly below the raw gas inlet and the heat storage medium inlet.

[0069] Furthermore, the catalyst feed port is located on the right side of the floating head at a 45° angle, the catalyst feed port is connected to the contact position of the floating head by welding, and the catalyst feed port is blocked by a blind plate during use of the synthesis device.

[0070] Furthermore, the catalyst discharge port and the raw gas reaction outlet are installed on the middle shaft of the reaction shell.

[0071] Furthermore, the starting end of the coil of the heat storage medium tube bundle is close to the flange surface at the upper end of the inner cylinder, passes through the wall of the inner cylinder and is connected to the heat storage medium inlet; the ending end of the coil of the heat storage medium tube bundle is connected to the outer cavity from the inner cylinder wall on the side close to the bottom of the inner cylinder.

[0072] The working principle of the green alcohol synthesis device of the present invention, which integrates molten salt heat transfer, heat storage and heat exchange, is as follows:

[0073] The raw gas is introduced into the raw gas tube bundle 12 from the raw gas inlet 18, and the raw gas rotates and flows from top to bottom in the raw gas tube bundle 12. The high-temperature molten salt inside the outer cavity 10 transfers heat to the outer wall of the raw gas tube bundle 12 by convection heat transfer, and the outer wall of the raw gas tube bundle 12 transfers heat to the inner wall by heat conduction. The temperature of the inner wall increases, and the raw gas takes away the heat from the inner wall of the raw gas tube bundle 12 by convection heat transfer, so as to increase the internal energy of the raw gas, thereby increasing the temperature of the raw gas; the heated raw gas is introduced into the inner cavity 9 of the reaction shell by the raw gas distribution component 4, and the raw gas generates methanol gas under the action of the catalyst in the inner cavity 9. The generated methanol gas is discharged from the raw gas reaction outlet 24 on the upper part of the floating head 5 and undergoes subsequent purification treatment. When the raw gas generates methanol gas, a large amount of reaction heat is also released. The generated reaction heat is stored and absorbed by the molten salt in the heat storage medium tube bundle 11 in the form of sensible heat;

[0074] After heat exchange, the molten salt stored within the outer cylinder 7 is pumped out by the circulating pump 19 and passed through the thermal storage medium inlet 17 into the thermal storage medium tube bundle 11 of the inner cavity 9. The heat generated by the reaction of the feed gas in the inner cavity 9 of the reaction shell 1 is transferred to the outer surface of the thermal storage medium tube bundle 11 via convection heat transfer. The heat from the outer surface of the thermal storage medium tube bundle 11 is then transferred to the inner surface via conduction heat transfer. The molten salt rotates from top to bottom within the thermal storage medium tube bundle 11, removing the heat from the inner surface via convection heat transfer. This increases the internal energy of the molten salt and its temperature. The high-temperature molten salt is then passed through the coil end of the thermal storage medium tube bundle into the outer cavity 10 to heat the feed gas.

[0075] When the raw gas contacts and reacts with the catalyst in the inner cavity 9, the multi-point thermocouples in the inner cavity 9 monitor the temperature changes in real time. When a sharp change in the temperature inside the synthesis device is detected, the multi-point thermocouples transmit the temperature signal to the circulation pump 19. After receiving the temperature signal, the circulation pump 19 increases the speed of the circulation pump, thereby increasing the circulation speed of the heat storage medium, further accelerating the removal of heat from the synthesis device, and providing protection for the safe operation of the synthesis device.

[0076] Any matters not described in the present invention are applicable to the prior art.

Claims

1. A molten salt heat transfer, heat storage, and heat exchange integrated green alcohol synthesis device, comprising a reaction shell, and a heat exchange component, a cavity, and a raw gas distribution component arranged inside the reaction shell, characterized in that: The reaction shell comprises a floating head, a reaction cylinder, and a lower head from top to bottom; the floating head is provided with a raw gas reaction outlet and a catalyst inlet; the lower head is provided with a catalyst discharge port and a heat storage medium outlet; the reaction cylinder is formed as a whole by an inner cylinder and an outer cylinder; The cavity includes an inner cavity formed by the inner wall of the inner cylinder and the inner wall of the floating head, and an outer cavity formed by the outer wall of the inner cylinder, the inner wall of the outer cylinder and the inner wall of the lower head; The heat exchange assembly includes a heat storage medium tube bundle located in the inner cavity and a raw gas tube bundle in the outer cavity; The raw gas distribution component is located at the bottom of the inner cavity surrounded by the inner cylinder; A heat storage medium inlet is provided on the inner cylinder, and the heat storage medium is located below the connection position between the inner cylinder and the floating head and above the outer cylinder; A raw gas inlet is provided at the upper portion of the outer cylinder; The raw gas pipe bundle is located inside the outer cavity and is arranged in a spirally coiled manner from top to bottom. The upper end is the starting end of the coil, which is connected to the raw gas inlet, and the lower end is the end of the coil, which is connected to the raw gas distribution assembly in the inner cylinder. Each ring of the raw gas pipe bundle is fixed to the inner wall of the outer cylinder and / or the outer wall of the inner cylinder by a support member. The heat storage medium tube bundle is located in the inner cavity of the inner cylinder and is arranged in a spiral shape along the middle axis of the reaction shell from top to bottom. The upper end is the starting end of the coil and is connected to the heat storage medium inlet. The lower end is the end of the coil and passes through the inner cylinder to communicate with the outer cavity. Each ring of the heat storage medium tube bundle is fixed to the inner wall of the inner cylinder by a support member. The heat storage medium outlet is connected to the circulation pump inlet through an external pipeline, and the circulation pump outlet is connected to the heat storage medium inlet through an external pipeline; the outer cavity and the interior of the heat storage medium tube bundle are filled with molten salt heat storage medium; The lower end of the floating head is welded with a flange, and the upper end of the inner cylinder is welded with a counter flange that matches the flange at the lower end of the floating head. The floating head flange and the counter flange of the inner cylinder are connected and fixed to the floating head and the inner cylinder by bolts, nuts and gaskets, which is a detachable connection; the outer cylinder is welded and fixed and covered on the outer layer of the inner cylinder; the lower end of the outer cylinder is rigidly connected to the lower head by welding; the inner cylinder is in the form of a cylinder with a closed lower end and an open upper end; The raw gas distribution assembly is composed of a raw gas elbow, a raw gas straight pipe and a raw gas distribution head connected by welding, and the raw gas elbow is connected to the end of the lower coil of the raw gas pipe bundle; The straight pipe section of the catalyst discharge port passes through the lower head and the bottom end of the inner cylinder in sequence and communicates with the inner cavity; the catalyst is filled in the inner cavity formed by the inner wall of the inner cylinder and the inner wall of the floating head, and the filling coefficient reaches 80%; The bottom of the inner cylinder is configured as a dome structure to facilitate catalyst unloading; The heat storage medium tube bundle, the outer cavity, the circulation pump, and the external pipeline together constitute a heat storage medium circulation system. The heat storage medium absorbs the reaction heat of the inner cavity and is used to heat the raw gas in the outer cavity. The entire heating process occurs in an independent synthesis device, without the need for an external preheater or heater. The working principle of the green alcohol synthesis device is: The raw gas is introduced into the raw gas tube bundle from the raw gas inlet, and the raw gas rotates and flows from top to bottom in the raw gas tube bundle. The high-temperature molten salt inside the outer cavity transfers heat to the outer wall of the raw gas tube bundle through convection heat transfer, and the outer wall of the raw gas tube bundle transfers heat to the inner wall through heat conduction. The temperature of the inner wall increases, and the raw gas takes away the heat from the inner wall of the raw gas tube bundle through convection heat transfer to increase the internal energy of the raw gas, thereby increasing the temperature of the raw gas; the heated raw gas is introduced into the inner cavity of the reaction shell by the raw gas distribution component, and the raw gas generates methanol gas under the action of the catalyst in the inner cavity. The generated methanol gas is discharged from the raw gas reaction outlet on the upper part of the floating head and undergoes subsequent purification treatment. When the raw gas generates methanol gas, a large amount of reaction heat is also released. The generated reaction heat is stored and absorbed by the molten salt in the heat storage medium tube bundle in the form of sensible heat; The molten salt stored inside the outer cylinder is pumped out by the circulating pump after heat exchange and passed into the heat storage medium tube bundle in the inner cavity through the heat storage medium inlet. The reaction heat generated by the raw gas reaction in the inner cavity of the reaction shell is transferred to the outer surface of the heat storage medium tube bundle through convection heat transfer. The heat on the outer surface of the heat storage medium tube bundle is transferred to the inner surface through heat conduction. The molten salt rotates from top to bottom in the heat storage medium tube bundle, removing the heat from the inner surface through convection heat transfer, thereby increasing the internal energy of the molten salt and raising the temperature of the molten salt. The high-temperature molten salt is then passed into the outer cavity through the coil end of the heat storage medium tube bundle to heat the raw gas. By using the spiral winding form, the heat storage medium in the tube bundle is at normal pressure, the pressure on each pipe in the tube bundle is small, and the thermal stress can be effectively eliminated by the rotating curvature; When the raw gas contacts and reacts with the catalyst in the inner cavity, the multi-point thermocouples in the inner cavity monitor the temperature changes in real time. When a sharp change in the temperature inside the synthesis device is detected, the multi-point thermocouples transmit the temperature signal to the circulation pump. After receiving the temperature signal, the circulation pump increases the speed of the circulation pump, thereby increasing the circulation speed of the heat storage medium, further accelerating the removal of heat from the synthesis device, and providing protection for the safe operation of the synthesis device.

2. The molten salt heat transfer, heat storage and heat exchange integrated green alcohol synthesis device according to claim 1, characterized in that: The upper edge of the outer cylinder is 30-50 cm away from the flange end surface of the inner cylinder.

3. The molten salt heat transfer, heat storage and heat exchange integrated green alcohol synthesis device according to claim 1, characterized in that: The raw gas distribution head adopts a spherical mesh structure.

4. The molten salt heat transfer, heat storage and heat exchange integrated green alcohol synthesis device according to claim 1, characterized in that: The support members at the same height are evenly distributed along the circumferential direction, and the support members have a horizontal support surface, and the winding coil is fixed to the horizontal support surface by a semicircular clamp; the length of the support member in the outer cavity is the same as the width of the outer cavity or extends from the outer wall of the inner cylinder to the outer side of the winding coil of the raw gas tube bundle, and the length of the support member in the inner cavity extends from the inner wall of the inner cylinder to the inner side of the winding coil of the heat storage medium tube bundle. The support member can meet the function of supporting the raw gas tube bundle / heat storage medium tube bundle.

5. The molten salt heat transfer, heat storage and heat exchange integrated green alcohol synthesis device according to claim 1, characterized in that: The straight pipe section of the catalyst discharge port is connected to the contact point between the lower head and the bottom end of the inner cylinder by welding; the catalyst discharge port is blocked by a blind plate during use of the synthesis device.

6. The molten salt heat transfer, heat storage and heat exchange integrated green alcohol synthesis device according to claim 1, characterized in that: The outer cavity is provided with oblique supports to provide support force for the inner cylinder. The oblique supports are evenly arranged around the outer surface of the inner cylinder. The specific number of oblique supports is set according to the total weight of the inner cylinder and the object carried inside the inner cylinder. The oblique support includes a lower pad, an upper pad, and an oblique support rod. The lower pad is made into a pad with the same curvature as the inner surface of the lower head, and the lower pad is fully welded to the lower head. The upper pad is made into a pad with the same curvature as the outer surface of the inner cylinder, and the upper pad is fully welded to the inner cylinder. The two ends of the oblique support rod are respectively welded to the upper pad and the lower pad.

7. The molten salt heat transfer, heat storage and heat exchange integrated green alcohol synthesis device according to claim 6, characterized in that: The angle between the oblique support and the outer surface of the inner cylinder is between 30-45 degrees.

8. The molten salt heat transfer, heat storage and heat exchange integrated green alcohol synthesis device according to claim 1, characterized in that: The heat storage medium is a binary salt or a ternary salt molten salt.

9. The molten salt heat transfer, heat storage and heat exchange integrated green alcohol synthesis device according to claim 1, characterized in that: The spacing between upper and lower adjacent pipes in the same type of raw gas pipe bundle and heat storage medium pipe bundle is 3-6 cm.

10. The molten salt heat transfer, heat storage and heat exchange integrated green alcohol synthesis device according to claim 1, characterized in that: Multiple thermocouples are arranged from top to bottom along the inner surface of the inner cylinder to monitor the internal temperature of the inner cylinder in real time. The circulation pump is a high-temperature resistant variable-frequency molten salt pump. By receiving the temperature signal emitted by the multiple thermocouples, the circulation pump frequency is controlled, thereby controlling the flow rate of the molten salt in the heat storage medium tube bundle and adjusting the heat transfer rate.

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