Single-tower single-pump low-power-consumption methanol water heat pump rectification process and equipment

Abstract

The application provides a single-tower single-pump low-power-consumption methanol water heat pump rectification process and equipment, which comprises an upper and lower distributed rectification tower body, a stripping tower body and a single heat pump compressor, and is matched with a first-stage preheater, a second-stage preheater, an intermediate heat pump reboiler, a tower bottom heat pump reboiler, the reboiler is provided with a disturbance scraping ring structure with switchable disturbance and descaling functions, and the maintenance frequency is reduced; during work, methanol water raw materials are gradually preheated, mixed with tower circulating liquid, heated and evaporated, the gas phase at the tower top is defoamed, and then is heated by double-stage compression gradient; after heat exchange, a condensing medium is recovered for preheating, a heat circulation system without steam consumption is formed, the multi-tower configuration of traditional rectification equipment is replaced, the structure is compact, the configuration is simplified, and the energy consumption and investment are reduced, so that the methanol water is completely separated and the product quality is stable.

Description

Technical Field

[0001] This invention belongs to the field of methanol-water distillation technology, and more specifically, it relates to a single-tower, single-pump, low-power methanol-water heat pump distillation process and equipment. Background Technology

[0002] In the fields of biopharmaceutical manufacturing, chemical pharmaceutical raw materials and preparation production, distillation separation is a process step to ensure product purity and remove impurities. It is widely used in key processes such as solvent recovery, active ingredient purification and impurity separation. With the continuous improvement of product purity requirements in the pharmaceutical industry, increasingly stringent environmental policies, and continuous increase in production cost control pressure, traditional distillation technology is no longer able to meet the needs of high-quality development in the industry. There is an urgent need for new distillation methods and systems that combine high-efficiency separation, low energy consumption, and stable reliability.

[0003] Traditional multi-tower coupled distillation processes mainly employ two technologies: conventional coupling processes and heat pump distillation processes. Conventional solutions primarily utilize dual-tower and triple-tower coupling processes. However, with the maturation of high-flow-rate, high-pressure-ratio combustible gas compressor technology, heat pump distillation processes are gradually replacing conventional coupling processes, becoming the mainstream development direction in the industry. However, while existing dual-tower and triple-tower coupling processes have significantly reduced steam consumption, saving approximately 40% and 55% respectively, they still require a large amount of steam to supply the coupled distillation system, making it impossible to achieve completely steam-free operation. Furthermore, the pressurization tower in dual-tower processes and the high-pressure tower in triple-tower processes are susceptible to deviations in product specifications due to their high operating pressures, making it difficult to guarantee separation accuracy. On the other hand, while single-tower, single-pump, high-power heat pump distillation processes can completely avoid steam heating, separating methanol and water using only a single distillation tower, this process requires a high-compression-ratio heat pump with high power consumption and energy consumption, resulting in poor overall economic efficiency. Therefore, it cannot fully meet the industry's demands for efficient, energy-saving, and low-cost production. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a single-tower, single-pump, low-power methanol-water heat pump distillation process and equipment, thereby solving the technical problems of high steam consumption, high power consumption, and poor overall economic efficiency of traditional distillation equipment in the prior art.

[0005] The purpose and effectiveness of the single-tower, single-pump, low-power methanol-water heat pump distillation process and equipment of the present invention are achieved by the following specific technical means: A single-tower, single-pump, low-power methanol-water heat pump distillation device includes a distillation tower and a stripping tower distributed vertically. The feed pipeline is connected in series with the primary preheater and the secondary preheater for preheating the methanol-water feedstock. The intermediate circulation pump on one side of the distillation column and the heat exchange medium outlet of the secondary preheater are both connected to the first connecting valve. The first connecting valve is connected to the heat exchange feed inlet of the intermediate heat pump reboiler for heating and evaporation. The bottom of the distillation column is connected to the heat exchange inlet of the bottom heat pump reboiler via a bottom circulation pump. The intermediate heat pump reboiler has the same structure as the bottom heat pump reboiler, and both internal baffle plates are equipped with multiple sets of baffle scraper ring structures for baffle or descaling. The turbulence scraper ring structure includes a support ring, and multiple sets of turbulence holes are opened on the turbulence plate for the heat exchange tubes to pass through. The support ring is installed in one set of turbulence holes. Multiple sets of scrapers are arranged circumferentially on the inner side of the support ring, and one end of each set of scrapers is provided with a scraping groove that contacts the outer wall of the heat exchange tube.

[0006] The above technical solution further includes: the turbulence scraper ring structure also includes a rotating ring, a sliding ring is provided on the inner side of the bearing ring, a snap ring is connected to the bottom of the rotating ring by screws, the sliding ring is rotatably snapped between the rotating ring and the snap ring, and a connecting ring plate is provided on the top of the snap ring; The bottom of the rotating ring is equipped with multiple sets of mounting seats corresponding to multiple sets of scrapers. The top of the connecting ring plate is equipped with mounting grooves corresponding to multiple sets of mounting seats. The bottom ends of the multiple sets of mounting seats are respectively locked in the multiple sets of mounting grooves. The inner side of each set of mounting seats is provided with mounting holes. The side of each set of scrapers away from the scraping groove is provided with a mounting rod. The mounting rod is fixedly inserted into the mounting hole. The multiple sets of scrapers are all inclined at 30-60°.

[0007] The above technical solution further includes: both the intermediate heat pump reboiler and the bottom heat pump reboiler are provided with two sets of partition plates for separating the heat exchange medium and the heat exchange material. Between the two sets of partition plates, there are multiple sets of support rods corresponding to multiple sets of turbulence scraper ring structures. The turbulence plate is slidably connected to the multiple sets of support rods. Two sets of fastening grooves are opened on the support rods. Each of the two sets of fastening grooves is provided with a limiting clip for limiting the sliding stroke of the turbulence plate. A rack is provided on one side of the support rod. The two sets of limiting clips are located at both ends of the rack.

[0008] The above technical solution further includes: a mounting ring is provided on the top of the rotating ring, a mounting bracket is fixedly provided on one side of the mounting ring, and two sets of meshing bevel gears are provided on the mounting bracket, one set of bevel gears is fixedly connected to a first gear on one side, and the first gear meshes with a rack; A gear ring is provided on the top of the mounting ring, and a second gear is fixedly connected to one side of another set of bevel gears. The second gear meshes with the gear ring.

[0009] The above technical solution further includes: a waterproof motor is provided at the bottom of one of the partition plates, the shaft end of the waterproof motor passes through one of the partition plates and is connected to a lifting screw, and a threaded bushing is provided at the center of the bottom of the spoiler, and the threaded bushing is slidably connected to the lifting screw; When the baffle is at the bottom dead center, multiple sets of scrapers are used to disturb the heat exchange medium flowing through the baffle orifice, breaking the fluid boundary layer on the outside of the heat exchange tube. As the baffle moves along the lifting screw, multiple scrapers move along the heat exchange tube and rotate axially along the baffle holes to peel off the scale layer attached to the outside of the heat exchange tube.

[0010] The above technical solution further includes: the heat exchange outlet of the intermediate heat pump reboiler is connected to the middle of the distillation column; the top exhaust port of the distillation column is connected to the inlet of the demister via a pipeline; the outlet of the demister is connected to the first-stage compression inlet of the heat pump compressor; the first-stage compressed gas outlet of the heat pump compressor is divided into two paths, one of which is connected to the heat exchange medium inlet of the intermediate heat pump reboiler; the heat exchange medium outlet of the intermediate heat pump reboiler is connected to the heat exchange inlet of the first-stage preheater via a pipeline; and the heat exchange outlet of the first-stage preheater is connected to the inlet of the reflux tank. Another path of the primary compressed gas outlet of the heat pump compressor is connected to the secondary compressed gas inlet of the heat pump compressor. The secondary compressed gas outlet of the heat pump compressor is connected to the heat exchange medium inlet of the heat pump reboiler at the bottom of the tower. The heat exchange medium outlet of the heat pump reboiler at the bottom of the tower is connected to the heat exchange feed inlet of the secondary preheater through a pipeline. The heat exchange outlet of the secondary preheater is connected to the inlet of the reflux tank.

[0011] The above technical solution further includes: the outlet of the reflux tank is connected to the input end of the reflux pump, the output end of the reflux pump is connected to the second connecting valve, the first output port of the second connecting valve is connected to the top reflux port on one side of the distillation column through a pipeline, and the second output port of the second connecting valve is connected to the product collection pipeline. The bottom outlet of the stripping column is connected to the input of the bottom circulation pump, the output of the bottom circulation pump is connected to the heat exchange inlet of the bottom heat pump reboiler, and the heat exchange outlet of the bottom heat pump reboiler is connected to the bottom inlet of the stripping column to form a bottom material circulation loop. The bottom of the stripping column is also connected to a bottom steam reboiler for starting up and providing a small amount of external steam.

[0012] The above technical solution further includes: the heat pump compressor adopts a two-stage compression or multi-stage compression structure and a single motor drive or multi-motor drive mode, wherein the intermediate compressed gas is used as a heat source to supply the intermediate heat pump reboiler, and the final compressed gas is used as a heat source to supply the bottom heat pump reboiler. The preferred configuration is a two-stage compression structure and a single motor drive mode. The packing or trays inside the distillation column and the stripping column are selected as the internal components for distillation separation according to the medium conditions, with packing being preferred. The intermediate heat pump reboiler and the bottom heat pump reboiler are equipped with low-temperature difference high-efficiency heat exchangers, and can adopt falling film evaporation, forced circulation evaporation, or thermosiphon evaporation structures, with falling film evaporation structure being preferred.

[0013] A single-tower, single-pump, low-power methanol-water heat pump distillation process, applied to the aforementioned single-tower, single-pump, low-power methanol-water heat pump distillation equipment, includes the following steps: Step 1: The methanol-water feedstock is fed into the feed pipeline and flows through the primary preheater and the secondary preheater in sequence for preheating to obtain the preheated methanol-water feedstock. Step 2: After preheating, the methanol-water feedstock is fed into the intermediate heat pump reboiler. At the same time, the intermediate circulation pump is started to extract the circulating liquid in the middle of the distillation column and transport it to the intermediate heat pump reboiler, so that the methanol-water feedstock and the circulating liquid in the column are mixed. The mixture is heated and evaporated by the intermediate heat pump reboiler. After evaporation, the material is returned to the middle of the distillation column. Step 3: The vapor phase inside the distillation column is discharged through the exhaust port at the top of the column and introduced into a demister for demisting treatment to remove liquid mist entrained in the vapor phase; Step 4: The defoamed gas phase is fed into the heat pump compressor for the first stage of compression to obtain the first stage compressed gas, which is then divided into two streams and fed into the return tank. Step 5: After the methanol condensate is cooled in the reflux tank, the reflux pump is started to pressurize the condensate and divide it into two streams. One stream returns to the top of the distillation column for reflux, and the other stream is discharged as methanol product through the product collection pipeline.

[0014] The above technical solution further includes: the primary compressed gas being divided into two streams and fed into the return tank includes: The primary compressed gas is divided into two paths. One path is fed into the intermediate heat pump reboiler to exchange heat and condense with the mixture in the tower. After condensation, the medium flows through the primary preheater for cooling and then into the reflux tank. The other path is fed into the heat pump compressor for secondary compression, resulting in secondary compressed gas. This secondary compressed gas is fed into the heat pump reboiler at the bottom of the tower to exchange heat and condense with the bottom material. After condensation, the medium flows through the secondary preheater for cooling and then into the reflux tank.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. By utilizing the two-stage compression structure of the heat pump compressor, the heat generated after compressing the gas phase at the top of the distillation column is utilized in stages. The first-stage compressed gas provides a heating source for the intermediate heat pump reboiler, and the second-stage compressed gas provides a heating source for the bottom heat pump reboiler. The condensed medium after heat exchange is then used to preheat the raw materials in the first-stage and second-stage preheaters, forming a complete heat recycling system. This achieves operation without steam consumption and meets the heating requirements for methanol-water distillation separation without the need for additional steam introduction. At the same time, the single-tower, single-pump structure simplifies equipment configuration and reduces power loss during equipment operation compared to the double-tower, double-pump process, further reducing overall energy consumption. This solves the technical problem of traditional distillation processes relying on steam heating and having high energy consumption, thus improving economic efficiency.

[0016] 2. By replacing the multi-tower configuration of traditional double-tower or triple-tower coupled processes with vertically distributed distillation and stripping columns, and with a single heat pump compressor and a single set of circulating pumps, the number of equipment and connecting pipelines is reduced. The structure is compact and occupies little space, thus reducing the initial investment cost of the equipment. In addition, the turbulence-enhancing scraper ring structure integrated in the intermediate heat pump reboiler and the bottom heat pump reboiler can achieve turbulence-enhanced heat exchange and descaling functions through a single structure state switching. There is no need to configure additional special turbulence devices and descaling equipment, which reduces the frequency of equipment downtime for maintenance, lowers maintenance costs and equipment maintenance difficulty, and ensures long-term stable operation of the system.

[0017] 3. The rectification and stripping columns work in tandem, combined with optimized packing and separation internals, to enhance gas-liquid contact mass transfer and improve separation accuracy. A demister at the top removes liquid droplets entrained in the gas phase, preventing them from entering the heat pump compressor and affecting compression efficiency, while also ensuring the purity of the subsequent condensate. At the process level, through staged preheating, stepped heat exchange, and reflux control, the temperature, pressure, and concentration distribution within the column are stabilized, avoiding product index fluctuations caused by excessively high operating pressures in traditional pressurized or high-pressure columns. This ensures methanol product purity meets standards, achieves complete separation of methanol and water, and solves the problem of product index deviations caused by traditional high-pressure operation. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the assembled structure of the present invention; Figure 2 This is a schematic diagram of the structure of the present invention after it has been unfolded; Figure 3 This is a schematic diagram of the disassembled structure of the intermediate heat pump reboiler or the bottom heat pump reboiler of the present invention. Figure 4 This is a schematic diagram of the structure of the turbulence scraper ring and the turbulence plate assembled in this invention; Figure 5 This is a schematic diagram of the structure of the turbulence scraper ring and the turbulence plate after separation in this invention; Figure 6 This is a schematic diagram of the assembled turbulence scraper ring structure in this invention; Figure 7 This is a schematic diagram of the disassembled turbulence scraper ring structure in this invention; Figure 8 yes Figure 7 Enlarged view of region A in the middle; Figure 9 This is a flowchart of the steps of a single-tower, single-pump, low-power methanol-water heat pump distillation process according to the present invention.

[0019] In the diagram, the correspondence between component names and drawing numbers is as follows: 101. Distillation column body; 102. Stripping column body; 103. Feed line; 104. Primary preheater; 105. Secondary preheater; 106. First connecting valve; 107. Intermediate heat pump reboiler; 108. Bottom circulation pump; 109. Bottom heat pump reboiler; 110. Defoamer; 111. Heat pump compressor; 112. Reflux tank; 113. Reflux pump; 114. Second connecting valve; 115. Product collection line; 116. Intermediate circulation pump; 117. Bottom steam reboiler; 201. Baffle plate; 202. Bearing ring; 203. Heat exchange tube; 204. Baffle hole; 205. Scraper; 206. Scraping groove; 207. Rotating ring; 208. Sliding ring; 209. Snap-fit ​​ring; 210. Connecting ring plate; 211. Mounting base; 212. Mounting groove; 213. Mounting hole; 214. Mounting rod; 215. Partition plate; 216. Support rod; 217. Limiting clip; 218. Rack; 219. Mounting ring; 220. Mounting bracket; 221. Bevel gear; 222. First gear; 223. Gear ring; 224. Second gear; 225. Waterproof motor; 226. Lifting screw; 227. Threaded bushing. Detailed Implementation

[0020] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the technical solutions of the present invention, but should not be used to limit the scope of protection of the present invention.

[0021] Example

[0022] As attached Figures 1 to 8 As shown: This invention provides a single-tower, single-pump, low-power methanol-water heat pump distillation device. The vertically distributed distillation column 101 and stripping column 102 operate collaboratively during methanol-water distillation, replacing the multi-tower configuration of traditional dual-tower or three-tower coupled processes. This reduces the number of devices and connecting pipelines, resulting in a compact structure and small footprint, thus lowering initial investment costs. The distillation column 101 and stripping column 102 use either packing or trays as internal distillation components, with packing being preferred. During operation, the gas and liquid phases within the column fully contact through the separation components, enhancing gas-liquid mass transfer and improving separation accuracy, thus facilitating efficient separation of methanol and water. The feed pipeline 103 transports the methanol-water feedstock, which is then... When the feed flows through the feed pipe 103, it passes through the primary preheater 104 and the secondary preheater 105 in sequence for step-by-step preheating. The temperature of the preheated feed material meets the requirements of subsequent heating and evaporation, avoiding excessive load on the subsequent reboiler. After the intermediate circulation pump 116 on one side of the distillation column 101 is started, the material in the middle of the distillation column 101 is extracted and transported to the first connecting valve 106. At the same time, the heat exchange medium outlet of the secondary preheater 105 is also connected to the first connecting valve 106, so that the methanol-water feed material is mixed with the circulating liquid in the column. The mixture is then fed into the heat exchange inlet of the intermediate heat pump reboiler 107. The intermediate heat pump reboiler 107 heats and evaporates the incoming mixture. The evaporated material is returned to the middle of the distillation column 101 to continue participating in the distillation process.

[0023] After the bottom circulation pump 108 at the bottom of the stripping column 102 starts, it draws out the material from the bottom of the stripping column 102 and transports it to the heat exchange inlet of the bottom heat pump reboiler 109. After the bottom heat pump reboiler 109 heats the material, the material returns to the bottom of the stripping column 102 to form a circulation, ensuring the stable operation of the stripping process. The intermediate heat pump reboiler 107 and the bottom heat pump reboiler 109 are selected from low-temperature difference high-efficiency heat exchangers, which can adopt falling film evaporation, forced circulation evaporation, and thermosiphon evaporation structures. The falling film evaporation structure is preferred, which can improve the heat exchange efficiency during operation. To reduce heat loss, the intermediate heat pump reboiler 107 and the bottom heat pump reboiler 109 have the same structure. Both have multiple sets of turbulence scraper ring structures on their internal baffles 201. Each turbulence scraper ring structure includes a support ring 202. The baffles 201 has multiple sets of turbulence holes 204 for the heat exchange tubes 203 to pass through. The support ring 202 is installed in one set of turbulence holes 204. Multiple sets of scrapers 205 are arranged circumferentially on the inner side of the support ring 202. One end of each set of scrapers 205 has a scraping groove 206 that contacts the outer wall of the heat exchange tubes 203. The turbulence scraper ring structure can achieve turbulence or descaling functions by switching states. No additional special turbulence devices and descaling equipment are required, which reduces the frequency of equipment downtime for maintenance, lowers maintenance costs and equipment maintenance difficulty, and ensures long-term stable operation of the system.

[0024] The turbulence scraper ring structure also includes a rotating ring 207, a sliding ring 208 inside the bearing ring 202, and a snap-fit ​​ring 209 connected to the bottom of the rotating ring 207 by screws. The sliding ring 208 is rotatably snapped between the rotating ring 207 and the snap-fit ​​ring 209. This arrangement allows the rotating ring 207 to rotate flexibly relative to the bearing ring 202. Simultaneously, the snap-fit ​​ring 209 is fixed to the rotating ring 207 by screws, limiting the axial displacement of the sliding ring 208 and preventing it from dislodging from its assembly position. A connecting ring plate 210 is provided at the top of the snap-fit ​​ring 209. Multiple mounting seats 211 are provided at the bottom of the rotating ring 207 corresponding to multiple sets of scrapers 205. Mounting grooves 212 are provided at the top of the connecting ring plate 210 corresponding to the multiple sets of mounting seats 211. The bottom ends of the multiple sets of mounting seats 211 are respectively snapped into the multiple sets of mounting grooves 212. The cooperation between the mounting base 211 and the mounting groove 212 enables the rapid positioning and assembly of the rotating ring 207 and the connecting ring plate 210, ensuring synchronous movement of both. Multiple mounting bases 211 have mounting holes 213 on their inner sides. Multiple scrapers 205 have mounting rods 214 on the side away from the scraping groove 206, which are fixedly inserted into the mounting holes 213. This assembly method secures the scrapers 205 to the mounting base 211, preventing them from loosening or falling off during turbulence or descaling. Multiple scrapers 205 are inclined at 30-60°. This inclination angle allows the scrapers 205 to effectively cut the heat exchange medium flowing through the turbulence holes 204 in turbulent conditions, enhancing the turbulence of the medium. In descaling conditions, it increases the contact area between the scrapers 205 and the outer wall of the heat exchange tube 203, improving the scale removal effect. When the equipment is running, the turbulence scraper ring structure is in a turbulence state. The rotating ring 207 remains stationary with the turbulence plate 201. The inclined scraper 205 obstructs and disturbs the heat exchange medium flowing through it, breaks the fluid boundary layer outside the heat exchange tube 203, and improves the heat exchange efficiency.

[0025] Both the intermediate heat pump reboiler 107 and the bottom heat pump reboiler 109 are equipped with two sets of partition plates 215. These partition plates 215 separate the heat exchange medium from the heat exchange material, preventing mixing. Between the two sets of partition plates 215, corresponding to multiple sets of turbulence-inducing scraper ring structures, are multiple sets of support rods 216. These support rods 216 provide mounting support for the turbulence-inducing plate 201. The turbulence-inducing plate 201 is slidably connected to the multiple support rods 216, allowing the turbulence-inducing plate 201 to move stably axially along the support rods 216. The support rod 216 has two sets of latching slots, each containing a limiting clip 217. The limiting clips 217 restrict the sliding stroke of the spoiler 201, preventing damage caused by the spoiler 201 exceeding a preset range during movement. A rack 218 is located on one side of the support rod 216, with the two sets of limiting clips 217 positioned at opposite ends of the rack 218, ensuring stable engagement of the transmission structure throughout the entire sliding stroke of the spoiler 201. A mounting ring 219 is located at the top of the rotating ring 207 for mounting... A mounting bracket 220 is fixedly installed on one side of the ring 219. The mounting bracket 220 is used to support two sets of meshing bevel gears 221. One set of bevel gears 221 has a first gear 222 fixedly connected to one side. The first gear 222 meshes with the rack 218 to realize the conversion of axial movement to rotational movement. A gear ring 223 is provided on the top of the mounting ring 219. A second gear 224 is fixedly connected to one side of the other set of bevel gears 221. The second gear 224 meshes with the gear ring 223 and can transmit rotational movement to the rotating ring. 207; A waterproof motor 225 is installed at the bottom of one set of partition plates 215. The waterproof motor 225 provides power for the movement of the spoiler 201 and the rotation of the scraper 205. The shaft end of the waterproof motor 225 passes through one set of partition plates 215 and is connected to a lifting screw 226. A threaded bushing 227 is installed at the center of the bottom of the spoiler 201. The threaded bushing 227 is slidably connected to the lifting screw 226. The rotational motion of the lifting screw 226 is converted into the axial movement of the spoiler 201 through the threaded engagement.

[0026] In this embodiment, when the equipment is performing normal distillation heat exchange operations and it is necessary to enhance the heat exchange effect, the waterproof motor 225 is started to drive the lifting screw 226 to rotate. The baffle 201 will move downward along the axial direction of the lifting screw 226 through the threaded bushing 227 until the baffle 201 touches the lower limit clamp 217. At this time, the baffle 201 is at the lower dead point, and the multiple sets of scrapers 205 remain stationary, disturbing the heat exchange medium flowing through the baffle holes 204, breaking the fluid boundary layer outside the heat exchange tube 203, accelerating the heat transfer between the heat exchange medium and the heat exchange tube 203, and improving the heat exchange. Efficiency; When a scale layer adheres to the outside of the heat exchange tube 203, affecting the heat exchange effect and requiring descaling, the waterproof motor 225 is started to drive the lifting screw 226 to rotate in the opposite direction. The baffle 201 moves upward along the axial direction of the lifting screw 226 through the threaded bushing 227. During the movement of the baffle 201, the mounting bracket 220 moves synchronously with the baffle 201. The first gear 222 on the mounting bracket 220 moves along the rack 218 and continuously meshes to rotate. The rotation of the first gear 222 drives one of the sets of bevel gears 221 that mesh with it to rotate. Through the meshing transmission of the two sets of bevel gears 221, the other... A set of bevel gears 221 rotates, and the rotating set of bevel gears 221 drives the second gear 224, which is fixedly connected to it, to rotate. The rotating second gear 224 meshes with the gear ring 223, thereby driving the gear ring 223 to rotate synchronously with the rotating ring 207. The rotating ring 207 drives multiple sets of scrapers 205, which are fixed to its inner side by the mounting base 211 and the mounting rod 214, to rotate axially along the turbulence hole 204. At this time, the multiple sets of scrapers 205 move axially along the heat exchange tube 203 with the turbulence plate 201, and also rotate axially along the turbulence hole 204. The scraping grooves 206 on the scrapers 205 and the... The outer wall of the heat exchange tube 203 is continuously contacted and rubbed to peel off the scale layer attached to the outside of the heat exchange tube 203. After the descaling is completed, the driving lifting screw 226 is rotated in the opposite direction to reset the baffle plate 201 to the lower dead point and restore the baffle enhanced heat exchange state. Throughout the process, the upper limit clip 217 can prevent the baffle plate 201 from moving upwards beyond its travel, ensuring the stable operation of the transmission structure and components. There is no need to configure an additional special drive device and transmission components. The two functions of baffle and descaling are switched through a single power source, ensuring the long-term stable operation of the intermediate heat pump reboiler 107 and the bottom heat pump reboiler 109.

[0027] The heat exchange outlet of the intermediate heat pump reboiler 107 is connected to the middle of the distillation column 101. The mixture heated and evaporated by the intermediate heat pump reboiler 107 returns to the middle of the distillation column 101 through this connecting pipeline to participate in the gas-liquid mass transfer separation process within the column, ensuring continuous distillation operation. The top exhaust port of the distillation column 101 is connected to the inlet of the demister 110 through a pipeline. The rising gas phase in the distillation column 101, carrying some liquid droplets, is discharged from the top exhaust port and transported to the demister 110 through a pipeline. The outlet of 0 is connected to the primary compression inlet of the heat pump compressor 111, and the treated gas phase enters the heat pump compressor 111 through this outlet. The primary compressed gas outlet of the heat pump compressor 111 is divided into two paths. One path is connected to the heat exchange medium inlet of the intermediate heat pump reboiler 107, providing a heating source for the intermediate heat pump reboiler 107. The heat exchange medium outlet of the intermediate heat pump reboiler 107 is connected to the heat exchange feed inlet of the primary preheater 104 through a pipeline. The condensed medium after heat exchange is discharged from this outlet and sent to the primary preheater 104. 04. Heat is provided for preheating the methanol-water feedstock in the primary preheater 104. The heat exchange outlet of the primary preheater 104 is connected to the inlet of the reflux tank 112. The condensate after releasing heat enters the reflux tank 112 for collection through this outlet. Another path of the primary compressed gas outlet of the heat pump compressor 111 is connected to the secondary compressed gas inlet of the heat pump compressor 111. The primary compressed gas enters the heat pump compressor 111 for secondary compression through this path. The secondary compressed gas outlet of the heat pump compressor 111 is connected to the heat exchange outlet of the heat pump reboiler 109 at the bottom of the tower. The heat medium inlet is connected, and the secondary compressed gas provides a heating source for the bottom heat pump reboiler 109. The heat exchange medium outlet of the bottom heat pump reboiler 109 is connected to the heat exchange feed inlet of the secondary preheater 105 through a pipeline. The condensed medium after heat exchange is discharged from the outlet and sent to the secondary preheater 105 to provide heat for preheating the methanol-water raw material in the secondary preheater 105. The heat exchange outlet of the secondary preheater 105 is connected to the inlet of the reflux tank 112. The condensed medium after releasing heat enters the reflux tank 112 for collection through the outlet.

[0028] In this embodiment, when the demister 110 is working, the gas phase flows through the internal separation structure inside the tank, and the entrained liquid droplets are intercepted and adsorbed, achieving secondary gas-liquid separation. This removes the liquid droplets entrained in the gas phase, preventing them from entering the heat pump compressor 111 and causing wear on compressor components or affecting compression efficiency. Simultaneously, it ensures that the condensate entering the reflux tank 112 is free of excess liquid droplet impurities, guaranteeing condensate purity. The heat pump compressor 111 adopts a two-stage or multi-stage compression structure and a single-motor or multi-motor drive mode. During actual operation, the appropriate structure and drive mode are selected based on the heating load and pressure requirements of the distillation system. In the active mode, the intermediate compressed gas is used as a heat source to supply the intermediate heat pump reboiler 107, and the final compressed gas is used as a heat source to supply the bottom heat pump reboiler 109. A two-stage compression structure with a single motor drive is preferred, resulting in more stable equipment operation and more efficient power transmission. During operation, the heat pump compressor 111 performs two-stage compression. The gas phase discharged from the top of the distillation column 101 and treated with defoaming is drawn into the compressor. First, primary compression increases the pressure and temperature. Then, part of the primary compressed gas is sent to the intermediate heat pump reboiler 107, while the other part enters the secondary compression stage. The pressure and temperature are further increased to form a secondary compressed gas. This two-stage compression method utilizes the heat generated after compressing the overhead gas phase of the distillation column in stages. The heat from the primary compressed gas is transferred to the mixture in the intermediate heat pump reboiler 107, providing energy for the heating and evaporation of the material. The heat from the secondary compressed gas is transferred to the bottom material in the bottom heat pump reboiler 109, providing energy for the circulating heating of the bottom material. After heat exchange between the intermediate heat pump reboiler 107 and the bottom heat pump reboiler 109, the compressed gas is cooled and condensed into a condensate. These condensates are then transported to the primary preheater 104 and the secondary preheater 105, respectively, to prepare for the subsequent heating. The methanol-water feedstock entering the preheater is preheated to provide heat, enabling heat recovery and utilization, forming a complete heat recycling system. This system achieves zero-steam operation, meeting the heating requirements of all stages in the methanol-water distillation separation process without the need for additional steam introduction. Compared to the dual-tower, dual-pump process, this equipment is equipped with only a single heat pump compressor 111 and a single set of circulating pipeline system, simplifying equipment configuration, reducing power loss and pipeline resistance loss during equipment operation, further reducing overall energy consumption, solving the technical problem of high energy consumption due to reliance on steam heating in traditional distillation processes, and improving the economic efficiency of equipment operation.

[0029] The outlet of the reflux tank 112 is connected to the input of the reflux pump 113. The methanol condensate collected in the reflux tank 112 enters the reflux pump 113 through the outlet. After the reflux pump 113 starts, it provides power for the condensate transportation, pressurizes the condensate, and delivers it to the second connecting valve 114. The output of the reflux pump 113 is connected to the second connecting valve 114. The second connecting valve 114 is used to regulate the flow direction of the condensate. Its first output port is connected to the top reflux port on one side of the distillation column 101 through a pipeline. After regulation, part of the condensate returns to the inside of the distillation column 101 through this path to provide reflux liquid for the top of the distillation column 101, maintain the gas-liquid balance and concentration stability in the column, and ensure the distillation separation effect. The second output port of the second connecting valve 114 is connected to the product collection pipeline 115. Another part of the condensate that meets the purity requirements enters the product collection pipeline 115 through this output port and is transported as methanol product to the subsequent storage or processing stage.

[0030] The bottom outlet of the stripping column 102 is connected to the input of the bottom circulation pump 108. The material at the bottom of the stripping column 102 enters the bottom circulation pump 108 through the bottom outlet. After the bottom circulation pump 108 starts, it pressurizes and transports the bottom material to the bottom heat pump reboiler 109. The output of the bottom circulation pump 108 is connected to the heat exchange inlet of the bottom heat pump reboiler 109. The material enters the bottom heat pump reboiler 109 through this inlet to be heated. The heat exchange outlet of the bottom heat pump reboiler 109 is connected to the bottom inlet of the stripping column 102. The heated material returns to the bottom of the stripping column 102 through this outlet, forming a bottom material circulation loop, continuously providing rising gas phase to the stripping column 102, and ensuring the stable operation of the stripping process.

[0031] The bottom of the distillation column 102 is also connected to a bottom steam reboiler 117. The bottom steam reboiler 117 is used to supply start-up and a small amount of external steam. During the start-up phase, the bottom heat pump reboiler 109 has not yet reached a stable heating state. At this time, the bottom steam reboiler 117 is started to supply steam to the bottom of the distillation column 102 to preheat the bottom material and help the system start up quickly. During normal operation, if the heating load of the bottom heat pump reboiler 109 is insufficient and cannot meet the heating requirements of the bottom material, the bottom steam reboiler 117 is started and supplies a small amount of steam to supplement it, ensuring that the temperature of the bottom material is stable within the preset range and ensuring that the distillation and separation effect is not affected.

[0032] Please see as follows Figure 9 As shown, the present invention also provides a single-tower, single-pump, low-power methanol-water heat pump distillation process, applied to the aforementioned single-tower, single-pump, low-power methanol-water heat pump distillation equipment, comprising the following steps: Step 1: The methanol-water raw material is fed into the feed pipeline 103 and flows through the primary preheater 104 and the secondary preheater 105 in sequence for preheating to obtain the preheated methanol-water raw material.

[0033] In this embodiment, the methanol-water feedstock is introduced into the system through the feed pipe 103. It flows continuously in the feed pipe 103 and sequentially passes through the primary preheater 104 and the secondary preheater 105. The residual heat of the condensate after heat exchange and condensation in the primary preheater 104 and the condensate after heat exchange and condensation in the secondary preheater 105 and the bottom heat pump reboiler 109 is used for step-by-step preheating. During the preheating process, the temperature of the methanol-water feedstock is gradually increased, and the heating load of the subsequent intermediate heat pump reboiler 107 is reduced to ensure that the feedstock reaches the temperature conditions suitable for heating and evaporation, and finally the preheated methanol-water feedstock is obtained.

[0034] Step 2: After preheating, the methanol-water feedstock is fed into the intermediate heat pump reboiler 107. At the same time, the intermediate circulation pump 116 is started to extract the circulating liquid in the middle of the distillation column 101 and transport it to the intermediate heat pump reboiler 107, so that the methanol-water feedstock and the circulating liquid in the column are mixed. The mixture is heated and evaporated by the intermediate heat pump reboiler 107. After evaporation, the material is returned to the middle of the distillation column 101.

[0035] In this embodiment, the preheated methanol-water feedstock is introduced into the heat exchange inlet of the intermediate heat pump reboiler 107 through a pipeline. At the same time, the intermediate circulation pump 116 is started. After the intermediate circulation pump 116 starts running, it extracts the circulating liquid in the middle of the distillation column 101 and transports it to the intermediate heat pump reboiler 107 through a pipeline, so that the preheated methanol-water feedstock and the circulating liquid in the column are fully mixed, improving the uniformity of material heating. The intermediate heat pump reboiler 107 uses the primary compressed gas delivered by the heat pump compressor 111 as a heat source to heat and evaporate the mixture, so that the methanol component in the mixture is fully vaporized. The heated and evaporated material is transported back to the middle of the distillation column 101 through the heat exchange outlet of the intermediate heat pump reboiler 107. After entering the column, it fully contacts and transfers mass with the liquid phase material descending in the column, participating in the subsequent methanol and water distillation separation process.

[0036] Step 3: The vapor phase inside the distillation column 101 is discharged through the exhaust port at the top of the column and introduced into the demister 110 for demisting treatment to remove the liquid mist entrained in the vapor phase.

[0037] In this embodiment, after the material is heated and evaporated by the intermediate heat pump reboiler 107 and returns to the distillation column 101, it fully contacts and transfers mass with the descending liquid material in the column. During the ascent, the vapor phase formed will carry some liquid droplets. The vapor phase is discharged through the top exhaust port at the top of the distillation column 101 and enters the demister 110 through a pipeline. The demister 110 uses an internal interception structure to demist the entering vapor phase, intercepting and separating the liquid droplets carried in the vapor phase, and preventing the liquid droplets from entering the subsequent equipment with the vapor phase.

[0038] Step 4: The defoamed gas phase is fed into the heat pump compressor 111 for the first stage of compression to obtain the first stage compressed gas, which is then divided into two streams and fed into the return tank 112.

[0039] In this embodiment, the first path of the primary compressed gas is introduced into the heat exchange medium inlet of the intermediate heat pump reboiler 107 through a pipeline. After entering the intermediate heat pump reboiler 107, it fully exchanges heat with the mixture in the tower inside the tank, providing the required heat for the heating and evaporation of the mixture. During the heat exchange process, the primary compressed gas releases heat and cools and condenses into a condensate. This condensate is discharged from the heat exchange medium outlet of the intermediate heat pump reboiler 107 and flows through the heat exchange channel of the primary preheater 104 through a pipeline, providing heat for the preheating of the methanol-water raw material flowing through the primary preheater 104, thus realizing heat recovery and utilization. After the condensate releases waste heat, its temperature decreases, and it is then introduced into the reflux tank 112 through a pipeline. The second path of the primary compressed gas is introduced into the secondary compression inlet of the heat pump compressor 111 through a pipeline, entering the heat pump compressor 111. 11. A second-stage compression is performed to further increase the pressure and temperature of the vapor phase, resulting in a secondary compressed gas that meets the heating requirements of the bottom of the tower. The secondary compressed gas is discharged from the secondary compressed gas outlet of the heat pump compressor 111 and is introduced into the heat exchange medium inlet of the bottom heat pump reboiler 109 through a pipeline. It fully exchanges heat with the bottom material in the bottom heat pump reboiler 109 to provide heat for heating the bottom material. During the heat exchange process, the secondary compressed gas releases heat and cools and condenses into a condensate. The condensate is discharged from the heat exchange medium outlet of the bottom heat pump reboiler 109 and flows through the heat exchange channel of the secondary preheater 105 through a pipeline to provide heat for preheating the methanol-water feedstock flowing through the secondary preheater 105, thus achieving heat recovery. After the condensate releases residual heat, its temperature decreases and it is then introduced into the reflux tank 112 through a pipeline.

[0040] Step 5: After the methanol condensate is cooled in the reflux tank 112, the reflux pump 113 is started to pressurize the condensate and divide it into two paths. One path returns to the top of the distillation column 101 for reflux, and the other path is extracted as methanol product through the product extraction pipeline 115.

[0041] In this embodiment, the methanol condensate transported from the primary preheater 104 and the secondary preheater 105 to the reflux tank 112 remains in the reflux tank 112 for further cooling, ensuring that the condensate temperature is stable within a range suitable for subsequent transport and separation, and avoiding excessive temperature from affecting the purity and transport efficiency of the condensate. After the condensate has cooled, the reflux pump 113 is started. The reflux pump 113 provides power for the transport of methanol condensate, pressurizing the condensate to give it sufficient pressure to overcome pipeline resistance and smoothly transport it to the second connecting valve 114. The second connecting valve 114 distributes the flow direction and flow rate of the pressurized condensate, with one path of condensate flowing through... The first output port of the second connecting valve 114 is used to transport the liquid to the top reflux port on one side of the distillation column 101 via pipeline, returning it to the top of the distillation column 101. After entering the column, the reflux liquid flows downward along the internal separation components, making full contact with the rising vapor material in the column for mass transfer, maintaining the stability of temperature, pressure and concentration distribution in the distillation column 101, and ensuring the continuity and separation accuracy of the distillation separation process. The other methanol condensate that meets the purity requirements enters the product collection pipeline 115 through the second output port of the second connecting valve 114, and is transported to subsequent storage equipment or processes via the product collection pipeline 115 to complete the collection as methanol product, ensuring the smooth production of qualified products.

[0042] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A single-tower, single-pump, low-power methanol-water heat pump distillation device, characterized in that: It includes a vertically distributed distillation column (101) and a stripping column (102). The feed pipeline (103) is connected in series with the primary preheater (104) and the secondary preheater (105) for preheating the methanol-water feedstock. The heat exchange medium outlets of the intermediate circulation pump (116) on one side of the distillation column (101) and the secondary preheater (105) are connected to the first connecting valve (106). The first connecting valve (106) is connected to the heat exchange feed inlet of the intermediate heat pump reboiler (107) for heating and evaporation. The bottom end of the distillation column (102) is connected to the heat exchange inlet of the bottom heat pump reboiler (109) via the bottom circulation pump (108). The intermediate heat pump reboiler (107) and the bottom heat pump reboiler (109) have the same structure and are equipped with multiple sets of turbulence scraper ring structures for turbulence or descaling on the internal baffles (201). The turbulence scraper ring structure includes a support ring (202), and multiple sets of turbulence holes (204) are opened on the turbulence plate (201) for the heat exchange tube (203) to pass through. The support ring (202) is installed in one set of turbulence holes (204). Multiple sets of scrapers (205) are arranged circumferentially on the inner side of the support ring (202). One end of the multiple sets of scrapers (205) is provided with a scraping groove (206) that contacts the outer wall of the heat exchange tube (203).

2. The single-tower, single-pump, low-power methanol-water heat pump distillation equipment according to claim 1, characterized in that: The turbulence scraper ring structure also includes a rotating ring (207), a sliding ring (208) is provided inside the bearing ring (202), a snap ring (209) is connected to the bottom of the rotating ring (207) by screws, the sliding ring (208) is rotatably snapped between the rotating ring (207) and the snap ring (209), and a connecting ring plate (210) is provided on the top of the snap ring (209). The bottom of the rotating ring (207) is provided with multiple sets of mounting seats (211) corresponding to multiple sets of scrapers (205), and the top of the connecting ring plate (210) is provided with mounting grooves (212) corresponding to multiple sets of mounting seats (211). The bottom ends of the multiple sets of mounting seats (211) are respectively locked in the multiple sets of mounting grooves (212). The inner side of the multiple sets of mounting seats (211) is provided with mounting holes (213). The side of the multiple sets of scrapers (205) away from the scraping groove (206) is provided with mounting rods (214). The mounting rods (214) are fixedly inserted into the mounting holes (213). The multiple sets of scrapers (205) are all inclined at 30-60°.

3. The single-tower, single-pump, low-power methanol-water heat pump distillation equipment according to claim 2, characterized in that: Both the intermediate heat pump reboiler (107) and the bottom heat pump reboiler (109) are equipped with two sets of partition plates (215) for separating the heat exchange medium and the heat exchange material. Between the two sets of partition plates (215), there are multiple sets of support rods (216) corresponding to multiple sets of turbulence scraper ring structures. The turbulence plate (201) is slidably connected to the multiple sets of support rods (216). Two sets of fastening grooves are provided on the support rods (216). Each of the two sets of fastening grooves is equipped with a limiting clip (217) for limiting the sliding stroke of the turbulence plate (201). A rack (218) is provided on one side of the support rod (216). The two sets of limiting clips (217) are located at both ends of the rack (218).

4. The single-tower, single-pump, low-power methanol-water heat pump distillation equipment according to claim 3, characterized in that: A mounting ring (219) is provided on the top of the rotating ring (207), and a mounting bracket (220) is fixedly provided on one side of the mounting ring (219). Two sets of meshing bevel gears (221) are provided on the mounting bracket (220). One set of bevel gears (221) is fixedly connected to a first gear (222) on one side. The first gear (222) meshes with the rack (218). The mounting ring (219) is provided with a toothed ring (223) on the top, and a second gear (224) is fixedly connected to one side of another set of bevel gears (221). The second gear (224) meshes with the toothed ring (223).

5. The single-tower, single-pump, low-power methanol-water heat pump distillation equipment according to claim 3, characterized in that: A waterproof motor (225) is installed at the bottom of one of the partition plates (215). The shaft end of the waterproof motor (225) passes through one of the partition plates (215) and is connected to a lifting screw (226). A threaded bushing (227) is installed at the center of the bottom of the spoiler (201). The threaded bushing (227) is slidably connected to the lifting screw (226). When the baffle (201) is at the bottom dead center, multiple scrapers (205) are used to disturb the heat exchange medium flowing through the baffle hole (204) and break the fluid boundary layer outside the heat exchange tube (203). When the baffle (201) moves along the lifting screw (226), multiple scrapers (205) move along the heat exchange tube (203) and rotate axially along the baffle hole (204) to peel off the scale layer attached to the outside of the heat exchange tube (203).

6. The single-tower, single-pump, low-power methanol-water heat pump distillation equipment according to claim 1, characterized in that: The heat exchange outlet of the intermediate heat pump reboiler (107) is connected to the middle of the distillation column (101). The top exhaust port of the distillation column (101) is connected to the inlet of the demister (110) through a pipeline. The outlet of the demister (110) is connected to the first-stage compression inlet of the heat pump compressor (111). The first-stage compressed gas outlet of the heat pump compressor (111) is divided into two paths. One path is connected to the heat exchange medium inlet of the intermediate heat pump reboiler (107). The heat exchange medium outlet of the intermediate heat pump reboiler (107) is connected to the heat exchange inlet of the first-stage preheater (104) through a pipeline. The heat exchange outlet of the first-stage preheater (104) is connected to the inlet of the reflux tank (112). Another path of the primary compressed gas outlet of the heat pump compressor (111) is connected to the secondary compressed gas inlet of the heat pump compressor (111). The secondary compressed gas outlet of the heat pump compressor (111) is connected to the heat exchange medium inlet of the heat pump reboiler (109) at the bottom of the tower. The heat exchange medium outlet of the heat pump reboiler (109) at the bottom of the tower is connected to the heat exchange feed inlet of the secondary preheater (105) through a pipeline. The heat exchange outlet of the secondary preheater (105) is connected to the inlet of the reflux tank (112).

7. The single-tower, single-pump, low-power methanol-water heat pump distillation equipment according to claim 6, characterized in that: The outlet of the reflux tank (112) is connected to the input end of the reflux pump (113), the output end of the reflux pump (113) is connected to the second connecting valve (114), the first output port of the second connecting valve (114) is connected to the top reflux port of the distillation column (101) through a pipeline, and the second output port of the second connecting valve (114) is connected to the product collection pipeline (115). The bottom outlet of the stripping column (102) is connected to the input end of the bottom circulation pump (108), the output end of the bottom circulation pump (108) is connected to the heat exchange inlet of the bottom heat pump reboiler (109), and the heat exchange outlet of the bottom heat pump reboiler (109) is connected to the bottom inlet of the stripping column (102) to form a bottom material circulation loop; the bottom of the stripping column (102) is also connected to a bottom steam reboiler (117) for supplying start-up steam and a small amount of external steam.

8. The single-tower, single-pump, low-power methanol-water heat pump distillation equipment according to claim 6, characterized in that: The heat pump compressor (111) adopts a two-stage compression or multi-stage compression structure and a single motor drive or multi-motor drive mode. The intermediate compressed gas is used as a heat source to supply the intermediate heat pump reboiler (107), and the final compressed gas is used as a heat source to supply the bottom heat pump reboiler (109). The preferred structure is a two-stage compression structure and a single motor drive mode. The packing or trays are selected as internal components for distillation separation in the distillation column body (101) and the stripping column body (102) according to the medium conditions, with packing preferred as the internal component for distillation separation; The intermediate heat pump reboiler (107) and the bottom heat pump reboiler (109) are selected from low temperature difference high efficiency heat exchangers, and can adopt falling film evaporation, forced circulation evaporation, and thermosiphon evaporation structures, with falling film evaporation structure being preferred.

9. A single-tower, single-pump, low-power methanol-water heat pump distillation process, applied to the single-tower, single-pump, low-power methanol-water heat pump distillation equipment according to any one of claims 1 to 9, characterized in that, Includes the following steps: Step 1: The methanol-water raw material is fed into the feed pipeline (103) and flows through the primary preheater (104) and the secondary preheater (105) in sequence for preheating to obtain the preheated methanol-water raw material; Step 2: After preheating, the methanol-water feedstock is fed into the intermediate heat pump reboiler (107), and at the same time, the intermediate circulation pump (116) is started to extract the circulating liquid in the middle of the distillation column (101) and transport it to the intermediate heat pump reboiler (107) so that the methanol-water feedstock and the circulating liquid in the column are mixed. The mixture is heated and evaporated by the intermediate heat pump reboiler (107). After evaporation, the material is returned to the middle of the distillation column (101). Step 3: The vapor phase inside the distillation column (101) is discharged through the exhaust port at the top of the column and introduced into the demister (110) for demisting treatment to remove the liquid foam entrained in the vapor phase; Step 4: The defoamed gas phase is fed into the heat pump compressor (111) for the first stage of compression to obtain the first stage of compressed gas, which is then divided into two streams and fed into the return tank (112). Step 5: After the methanol condensate is cooled in the reflux tank (112), the reflux pump (113) is started to pressurize the condensate and divide it into two paths. One path returns to the top of the distillation column (101) for reflux, and the other path is extracted as methanol product through the product extraction pipeline (115).

10. The single-tower, single-pump, low-power methanol-water heat pump distillation process according to claim 9, characterized in that, The primary compressed gas is divided into two streams and fed into the return tank (112), including: The primary compressed gas is divided into two paths. One path is fed into the intermediate heat pump reboiler (107) to exchange heat with the mixture in the tower and condense. After condensation, the medium flows through the primary preheater (104) for cooling and then into the reflux tank (112). The other path is fed into the heat pump compressor (111) for secondary compression, and the resulting secondary compressed gas is fed into the bottom heat pump reboiler (109) to exchange heat with the bottom material and condense. After condensation, the medium flows through the secondary preheater (105) for cooling and then into the reflux tank (112).

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