A heat pump distillation device and a distillation system based on steam compression

Abstract

The present invention relates to the field of distillation separation technology, and discloses a heat pump distillation device and a distillation system based on steam compression. In the present invention, steam condensation separation produces condensate and residual steam, the steam condensate accumulates at the bottom of the distillation tower body and is re-input into the reboiler from the overflow port, the residual steam is compressed into liquid by the compressor located at the head end, the liquid is distributed by the separator and output to the reflux pipe and the output pipe respectively, the liquid output from the reflux pipe returns to the reboiler corresponding to the distillation tower body located at the head end, the liquid output from the output pipe enters the reboiler corresponding to the next distillation tower body, and the next distillation tower body re-performs a circulation process with the previous distillation tower body and the corresponding output separation mechanism and the corresponding reboiler, and the effective separation of the distillation can be ensured through the continuous liquid circulation and multiple separations between multiple distillation tower bodies, and the purity of each output distillation separation product can be ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of distillation separation, and in particular to a heat pump distillation device and a distillation system based on steam compression. Background Art

[0002] The distillation process is an important part of the petrochemical industry. In the process of conventional distillation towers, most of the energy input by the reboiler at the bottom of the tower is taken away by cooling air or cooling water at the top of the tower. Generally, this part of energy cannot be further recycled and the thermodynamic efficiency is very low. The usual heat pump distillation is to pressurize and heat the steam at the top of the distillation tower, so that it can be used as the heat source of the reboiler at the bottom of the tower, and the condensation latent heat of the steam at the top of the tower can be recovered. This process is also called compression heat pump distillation.

[0003] Steam compression heat pump distillation is an innovative energy-saving technology that combines the principles of traditional distillation and heat pumps. It uses a compressor to increase the pressure and temperature of the top steam, converting it into a heat source for the bottom reboiler, thereby achieving effective recycling of heat. This process not only greatly improves the thermal efficiency of the distillation process, but also significantly reduces energy consumption and operating costs. The thermodynamic principle of steam compression heat pump distillation technology is the reverse Carnot cycle, which is an efficient heat transfer mechanism. In this process, the system converts low-temperature and low-pressure steam into high-temperature and high-pressure steam through a compressor, thereby realizing the transfer of heat from the low-temperature area to the high-temperature area, overcoming the natural heat transfer direction. The application of steam compression heat pump distillation technology in the chemical industry is becoming more and more extensive.

[0004] Existing heat pump distillation devices usually use multiple distillation towers in series for continuous distillation because the distillation products produced by continuous distillation have high purity. However, during the continuous distillation process, it is necessary to maintain the pressure balance inside each distillation tower. Pressure imbalance can easily lead to the generation of mist inside the distillation tower, which in turn can easily lead to temperature loss inside the distillation tower and liquid decompression, which can easily cause harm. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a heat pump distillation device and a distillation system based on steam compression.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A heat pump distillation device comprises a fixed support and a plurality of distillation tower bodies arranged in sequence, the top of each distillation tower body is connected to an output separation mechanism, the distillation tower body at the front end is connected to the distillation tower body at the rear end through the output separation mechanism, and the distillation tower body at the tail end outputs the product through the output separation mechanism; the output separation mechanism comprises a gas pipeline, a compressor, a separator, a reflux pipeline and an output pipeline, and the top of each distillation tower body is provided with a discharge port; the two ends of the gas pipeline are respectively connected to the discharge port and the compressor, the steam output from the top of the distillation tower body can be compressed into liquid by the compressor, and the liquid is distributed to the discharge port through the separator. The reflux pipe and the output pipe are output; a reboiler and a return mechanism are arranged at the bottom end of each distillation tower body, and a feed port and an overflow port are arranged at the bottom end of each distillation tower body, and the height of the overflow port is higher than the height of the feed port; the other end of the output pipe is connected with the feed end of the reboiler corresponding to the next distillation tower body; the other end of the reflux pipe is connected with the feed end of the reboiler corresponding to the current distillation tower body, the overflow port is connected with the feed end of the reboiler, and the reboiler is connected with the feed port through the return mechanism; the liquid input into the reboiler can be heated into steam again and then injected into the corresponding bottom end of the distillation tower body through the return mechanism.

[0008] Preferably, the steam temperature output from the discharge port of each distillation tower body is the same, the steam temperature input from the feed port of each distillation tower body is the same, and the steam temperature input from the feed port inside each distillation tower body is higher than the steam temperature output from the discharge port.

[0009] Preferably, a plurality of liquefied layers are sequentially arranged inside each of the distillation tower bodies from low to high, and the temperature of each of the liquefied layers decreases with increasing height of the position; and the surface temperature of each of the liquefied layers at the same height inside each of the distillation tower bodies is the same.

[0010] Preferably, each of the liquefaction layer plates includes a connecting layer plate, a steam port is provided in the center of the connecting layer plate, the connecting layer plate is inclined downward from one end close to the inner wall of the distillation tower body toward one end of the steam port, and a plurality of air holes are provided on the surface of the connecting layer plate; a drainage groove is provided at one end of the top of the connecting layer plate close to the inner wall of the distillation tower body, and a drainage hole is provided at the bottom of the drainage groove.

[0011] Preferably, a scraper unit is suspended inside the steam port, and the scraper unit includes a scraper bracket, a scraper strip, a scraper driving impeller and a water retaining ring plate; the water retaining ring plate is installed at one end of the connecting layer plate close to the steam port, and the water retaining ring plate is inclined downward from the end close to the steam port toward one end of the inner wall of the distillation tower body; the scraper strip bypasses the upper and lower side surfaces of the water retaining ring plate, and the scraper strip is in contact with the upper and lower side surfaces of the water retaining ring plate and the lower surface of the connecting layer plate.

[0012] Preferably, the scraper bracket is embedded in the steam port, the scraper driving impeller is rotatably connected to the scraper bracket, and the scraper strip is coaxially fixed to the scraper driving impeller; under the action of the airflow inside the distillation tower body, the scraper driving impeller rotates while driving the scraper strip to move, causing rotation around the axis of the connecting layer plate, thereby scraping the water film attached to the upper and lower sides of the water retaining ring plate and the lower surface of the connecting layer plate.

[0013] Preferably, the reboiler includes a constant pressure tank and a heat exchanger, the constant pressure tank and the heat exchanger are connected via a flow limiting valve, and the output pipe and the overflow port are both connected to the constant pressure tank; the liquid output from the output pipe and the overflow port is first input into the constant pressure tank for temporary storage, and then input into the heat exchanger at a constant flow rate through the flow limiting valve, and heat exchange is performed inside the heat exchanger to regenerate steam.

[0014] Preferably, the recirculation mechanism includes a gas storage tank, a gas supply pipe and a balance pipe, the gas storage tank is connected to the output end of the heat exchanger, one end of the gas supply pipe is connected to the gas storage tank, and the other end of the gas supply pipe is connected to the feed port; an air pressure balance unit is provided in the middle of the gas supply pipe, the gas supply pipe is connected to the balance pipe through the air pressure balance unit, and one end of the balance pipe away from the air pressure balance unit is connected to the gas storage tank; the air pressure balance unit can keep the steam flow rate delivered by the gas supply pipe to the feed port constant by controlling the gas flow between the balance pipe and the gas storage tank.

[0015] Preferably, the air pressure balancing unit includes an external balancing tube, a ventilation mounting plate is arranged in the center of the external balancing tube, sealing ring plates are arranged at both ends of the external balancing tube, and balancing pistons are connected to both sides of the ventilation mounting plate through balancing springs; the air pressure at both ends of the external balancing tube can respectively act on the end of the balancing piston away from the ventilation mounting plate; when the air pressure at both ends of the external balancing tube is unbalanced, the two balancing pistons can be driven simultaneously to overcome the elastic force of the corresponding balancing springs and move, and the two balancing pistons can be driven to separate from the corresponding sealing ring plates respectively, thereby connecting the two ends of the external balancing tube.

[0016] A steam compression-based distillation system, using the above-mentioned heat pump distillation device, comprises the following steps:

[0017] The liquid to be distilled is input from the reboiler corresponding to the distillation tower body at the head end, and after being converted into steam inside the reboiler, it is input to the distillation tower body at the head end through the return mechanism at a constant steam flow rate;

[0018] Inside the distillation tower at the head end, the steam is condensed and separated to produce condensate and residual steam. The condensate is accumulated at the bottom of the distillation tower and re-input into the reboiler from the overflow port, and the residual steam enters the gas pipeline of the output separation mechanism corresponding to the distillation tower at the head end;

[0019] The residual steam is compressed into liquid by the compressor, and the liquid is distributed by the separator and output to the reflux pipe and the output pipe respectively. The liquid output from the reflux pipe returns to the reboiler corresponding to the distillation tower body at the head end, and the liquid output from the output pipe enters the reboiler corresponding to the next distillation tower body;

[0020] After being separated by several distillation tower bodies in sequence, the distillation product is output from the output pipeline corresponding to the distillation tower body at the tail end.

[0021] Compared with the prior art, the present invention provides a heat pump distillation device and a distillation system based on steam compression, which have the following beneficial effects:

[0022] 1. In this heat pump distillation device, the steam inside the distillation tower body is condensed and separated at a gradually decreasing temperature to produce condensate and residual steam. The steam condensate accumulates at the bottom of the distillation tower body and is re-input into the reboiler from the overflow port, and the residual steam enters the gas pipeline of the output separation mechanism corresponding to the distillation tower body at the head end; the residual steam is compressed into liquid by the compressor at the head end, and the liquid is distributed by the separator and output to the reflux pipeline and the output pipeline respectively. The liquid output from the reflux pipeline returns to the reboiler corresponding to the distillation tower body at the head end, and the liquid output from the output pipeline enters the gas pipeline corresponding to the next distillation tower body. Inside the reboiler, the next distillation tower body repeats the circulation process with the previous distillation tower body and the corresponding output separation mechanism and the corresponding reboiler, so that the liquid that needs to be distilled and separated is separated by several distillation tower bodies in sequence, and the distillation product is output from the output pipeline corresponding to the distillation tower body located at the tail end, and the distillation bottom liquid is output from the bottom end of the distillation tower body located at the head end. Through the continuous liquid circulation and multiple separations between multiple distillation tower bodies, two or more distillation separation products that need to be separated can be effectively separated, thereby ensuring the effective separation of distillation and ensuring the purity of each output distillation separation product.

[0023] 2. This heat pump distillation device, through the action of each reboiler, keeps the temperature of the steam input into each distillation tower body from each feed port equal, and because the height of each distillation tower body and the environment in which it is located are consistent, after the steam is condensed through each distillation tower body, the steam temperature output from the discharge port of each distillation tower body is the same. Similarly, since the positions of the liquefied layers are the same, the surface temperatures of the liquefied layers at the same height inside each distillation tower body are the same, so that the environment inside each distillation tower body is consistent, the distillation process can be carried out effectively, and the raw materials can be separated more effectively.

[0024] 3. In this heat pump distillation device, inside the distillation tower body, the steam airflow can rise through the air holes and steam ports of each liquefied layer plate, and the liquid condensed on the upper surface of the connecting layer plate can be drained into the drainage groove and guided along the drainage holes to the inner wall of the distillation tower body under the inclination of the connecting layer plate, and can gradually accumulate at the bottom of the distillation tower body. Under the action of the airflow inside the distillation tower body, the scraper drives the impeller to rotate and drives the scraper strip to move, generating a rotation around the axis of the connecting layer plate, which affects the upper and lower sides of the water retaining ring plate and the connecting layer plate. The water film attached to the lower surface can be scraped off, and the water film can be promoted to separate from the lower surface of each connecting layer plate to reduce the influence on the continued condensation of steam, and the rotation of each scraping liquid driving impeller and each water retaining ring plate can generate mechanical rotation inside the distillation tower body, and mist can be generated inside the distillation tower body. When the mist moves upward along the inside of the distillation tower body, the rotation of each scraping liquid driving impeller and each water retaining ring plate suppresses the continued rise of the mist, so as to prevent the mist from spreading to the top of the distillation tower body and damaging the various structures at the rear end.

[0025] 4. This heat pump distillation device, through the setting of a constant pressure tank, the constant pressure tank and the heat exchanger are connected through a flow limiting valve, the output pipe and the overflow port are connected to the constant pressure tank, the liquid output from the output pipe and the overflow port is first input into the constant pressure tank for temporary storage, and then input into the heat exchanger at a constant flow rate through the flow limiting valve to ensure the constant flow of the liquid input into the heat exchanger, ensure the heat exchange stability of the heat exchanger, and then ensure the constant temperature of the steam output from the heat exchanger; through the action of the gas storage tank, the balance pipe and the air pressure balance unit, when the air pressure at both ends of the external balance pipe is unbalanced, the two balance pistons can be driven at the same time to overcome the elastic force of the corresponding balance spring and move, drive the two balance pistons to separate from the corresponding sealing ring plates, connect the two ends of the external balance pipe, control the gas flow between the balance pipe and the gas storage tank, keep the steam flow rate transported by the gas pipe to the feed port constant, and effectively ensure that the steam flow rate can be within the distillation range of each distillation tower body, which can more effectively ensure the distillation inside the distillation tower body. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1This is one of the three-dimensional structural schematic diagrams of a heat pump distillation device of the present invention;

[0027] Figure 2 This is a second schematic diagram of the three-dimensional structure of a heat pump distillation device of the present invention;

[0028] Figure 3 It is a schematic diagram of a distillation tower body and its corresponding output separation mechanism, reboiler and return mechanism of a heat pump distillation device of the present invention;

[0029] Figure 4 A schematic diagram of the internal structure of a distillation tower body of a heat pump distillation device of the present invention;

[0030] Figure 5 It is a schematic diagram of the three-dimensional structure of an output separation mechanism of a heat pump distillation device of the present invention;

[0031] Figure 6 It is a three-dimensional structural schematic diagram of a reboiler and a return mechanism of a heat pump distillation device of the present invention;

[0032] Figure 7 It is a cross-sectional schematic diagram of a gas pressure balance unit of a heat pump distillation device of the present invention;

[0033] Figure 8 This is one of the three-dimensional structural schematic diagrams of a liquefied layer plate of a heat pump distillation device of the present invention;

[0034] Fig. 9 This is the second schematic diagram of the three-dimensional structure of the liquefied layer plate of the heat pump distillation device of the present invention.

[0035] In the figure: 1. Fixed bracket; 2. Distillation tower body; 21. Discharge port; 22. Feed port; 23. Overflow port; 3. Output separation mechanism; 31. Gas pipeline; 32. Compressor; 33. Separator; 34. Reflux pipeline; 35. Output pipeline; 4. Reboiler; 41. Constant pressure tank; 42. Heat exchanger; 5. Return mechanism; 51. Gas storage tank; 52. Gas transmission pipe; 53. Balance pipe; 54. Gas pressure balance Unit; 541, external balance pipe; 542, ventilation mounting plate; 543, sealing ring plate; 544, balance spring; 545, balance piston; 6, liquefaction layer plate; 61, connecting layer plate; 611, air vent; 612, drainage groove; 613, drainage hole; 62, steam port; 63, scraper unit; 631, scraper bracket; 632, scraper strip; 633, scraper drive impeller; 634, water retaining ring plate. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] As introduced in the background technology, there are deficiencies in the prior art. In order to solve the above technical problems, the present application proposes a heat pump distillation device and a distillation system based on steam compression.

[0038] Embodiment 1:

[0039] Please refer to Figure 1-Figure 9 A heat pump distillation device comprises a fixed support 1 and a plurality of distillation tower bodies 2 arranged in sequence, the top of each distillation tower body 2 is connected to an output separation mechanism 3, the distillation tower body 2 at the front end is connected to the distillation tower body 2 at the rear end through the output separation mechanism 3, and the distillation tower body 2 at the tail end outputs the product through the output separation mechanism 3; the output separation mechanism 3 comprises a gas pipeline 31, a compressor 32, a separator 33, a reflux pipeline 34 and an output pipeline 35, and the top of each distillation tower body 2 is provided with a discharge port 21; the two ends of the gas pipeline 31 are respectively connected to the discharge port 21 and the compressor 32, the steam output from the top of the distillation tower body 2 can be compressed into liquid by the compressor 32, and the liquid passes through the separator 3 3 is distributed and output to the reflux pipe 34 and the output pipe 35 respectively; a reboiler 4 and a return mechanism 5 are arranged at the bottom of each distillation tower body 2, and a feed port 22 and an overflow port 23 are arranged at the bottom of each distillation tower body 2, and the height of the overflow port 23 is higher than the height of the feed port 22; the other end of the output pipe 35 is connected with the feed end of the reboiler 4 corresponding to the next distillation tower body 2; the other end of the reflux pipe 34 is connected with the feed end of the reboiler 4 corresponding to the current distillation tower body 2, the overflow port 23 is connected with the feed end of the reboiler 4, and the reboiler 4 is connected with the feed port 22 through the return mechanism 5; the liquid input into the reboiler 4 can be heated into steam again and then injected into the corresponding bottom of the distillation tower body 2 through the return mechanism 5.

[0040] When in use, firstly, the liquid to be distilled and separated is input from the reboiler 4 corresponding to the distillation tower body 2 at the head end, the liquid is converted into steam inside the reboiler 4 at the head end, and the steam is input into the distillation tower body 2 at the head end through the return mechanism 5 at a constant steam flow rate, and the steam inside the distillation tower body 2 is condensed and separated at a gradually decreasing temperature to produce condensate and residual steam, the steam condensate accumulates at the bottom of the distillation tower body 2 and is re-input into the reboiler 4 from the overflow port 23, and the residual steam enters the gas pipeline 31 of the output separation mechanism 3 corresponding to the distillation tower body 2 at the head end; the residual steam is compressed into liquid by the compressor 32 at the head end, and the liquid is distributed by the separator 33 and output to the reflux pipeline 34 and the output pipeline 35 respectively, the liquid output from the reflux pipeline 34 returns to the reboiler 4 corresponding to the distillation tower body 2 at the head end, and the liquid output from the output pipeline 35 enters the next distillation tower The distillation tower body 2 is connected to the distillation tower body 2 by a reboiler 4, and the next distillation tower body 2 repeats the circulation process with the previous distillation tower body 2 and the corresponding output separation mechanism 3 and the corresponding reboiler 4, so that after being separated by several distillation tower bodies 2 in sequence, the distillation product (the distillation separation product with a low boiling point) is output from the output pipe 35 corresponding to the distillation tower body 2 located at the tail end, and the distillation bottom liquid (the distillation separation product with a high boiling point) is output from the bottom end of the distillation tower body 2 located at the head end. Through continuous liquid circulation and multiple separations between multiple distillation tower bodies 2, two or more distillation separation products that need to be separated can be effectively separated (when multiple distillation separation products need to be separated, the number of distillation tower bodies 2 needs to be increased according to demand, and the corresponding distillation separation products with the required intermediate boiling point are output from the bottom end of the distillation tower body 2 located in the middle section), thereby ensuring the effective separation of distillation and the purity of each distillation separation product output.

[0041] Embodiment 2:

[0042] Please refer to Figure 1-Figure 9 , which is different from the above-mentioned embodiment, the steam temperature output from the discharge port 21 of each distillation tower body 2 is the same, the steam temperature input from the feed port 22 of each distillation tower body 2 is the same, and the steam temperature input from the feed port 22 inside each distillation tower body 2 is higher than the steam temperature output from the discharge port 21.

[0043] A plurality of liquefied layers 6 are arranged in sequence from low to high inside each distillation tower body 2, and the temperature of each liquefied layer 6 decreases with increasing height; the surface temperature of each liquefied layer 6 at the same height inside each distillation tower body 2 is the same.

[0044] When in use, through the action of each reboiler 4, the temperature of the steam input into each distillation tower body 2 from each feed port 22 is kept equal, and because the height and the environment of each distillation tower body 2 are kept consistent, after the steam is condensed through each distillation tower body 2, the steam temperature output from the discharge port 21 of each distillation tower body 2 is the same. Similarly, since the positions of the liquefaction layers 6 are the same, the surface temperatures of the liquefaction layers 6 at the same height inside each distillation tower body 2 are the same, so that the environment inside each distillation tower body 2 is consistent, the distillation process can be carried out effectively, and the raw materials can be separated more effectively.

[0045] Each liquefaction layer plate 6 includes a connecting layer plate 61, a steam port 62 is provided in the center of the connecting layer plate 61, the connecting layer plate 61 is inclined downward from one end close to the inner wall of the distillation tower body 2 toward one end of the steam port 62, and a plurality of air holes 611 are provided on the surface of the connecting layer plate 61; a drainage groove 612 is provided at one end of the top of the connecting layer plate 61 close to the inner wall of the distillation tower body 2, and a drainage hole 613 is provided at the bottom of the drainage groove 612.

[0046] A scraper unit 63 is hoisted inside the steam port 62, and the scraper unit 63 includes a scraper bracket 631, a scraper strip 632, a scraper driving impeller 633 and a water retaining ring plate 634; the water retaining ring plate 634 is installed at one end of the connecting layer 61 close to the steam port 62, and the water retaining ring plate 634 is inclined downward from the end close to the steam port 62 toward the end of the inner wall of the distillation tower body 2; the scraper strip 632 bypasses the upper and lower side surfaces of the water retaining ring plate 634, and the scraper strip 632 is in contact with the upper and lower side surfaces of the water retaining ring plate 634 and the lower surface of the connecting layer 61.

[0047] The scraper bracket 631 is embedded in the steam port 62, the scraper driving impeller 633 is rotatably connected to the scraper bracket 631, and the scraper strip 632 is coaxially fixed to the scraper driving impeller 633; ​​under the action of the airflow inside the distillation tower body 2, the scraper driving impeller 633 rotates and drives the scraper strip 632 to move, generating a rotation around the axis of the connecting layer plate 61, scraping the water film attached to the upper and lower sides of the water retaining ring plate 634 and the lower surface of the connecting layer plate 61.

[0048] When in use, inside the distillation tower body 2, the steam flow can rise through the air holes 611 and the steam ports 62 of each liquefied layer plate 6, and the liquid condensed on the upper surface of the connecting layer plate 61 can be drained into the drainage groove 612 and guided to the inner wall of the distillation tower body 2 along the drainage holes 613 under the inclination of the connecting layer plate 61, and can gradually accumulate at the bottom end of the distillation tower body 2. Under the action of the airflow inside the distillation tower body 2, the scraping drive impeller 633 rotates and drives the scraping strip 632 to move, generating a rotation around the axis of the connecting layer plate 61, which affects the upper and lower sides of the water retaining ring plate 634 and the connecting layer plate 61. The water film attached to the lower surface of the layer plate 61 is scraped off, which can promote the separation of the water film from the lower surface of each connected layer plate 61 to reduce the impact on the continued condensation of steam, and through the rotation of each scraping driving impeller 633 and each water retaining ring plate 634, mechanical rotation can be generated inside the distillation tower body 2, and mist can be generated inside the distillation tower body 2. When the mist moves upward along the inside of the distillation tower body 2, the rotation of each scraping driving impeller 633 and each water retaining ring plate 634 can suppress the continued rise of the mist, thereby preventing the mist from spreading to the top of the distillation tower body 2 and damaging the various structures at the rear end.

[0049] Embodiment three:

[0050] Please refer to Figure 1-Figure 9 , which is different from the above-mentioned embodiment, is that the reboiler 4 includes a constant pressure tank 41 and a heat exchanger 42, the constant pressure tank 41 and the heat exchanger 42 are connected via a flow limiting valve, and the output pipe 35 and the overflow port 23 are both connected to the constant pressure tank 41; the liquid output from the output pipe 35 and the overflow port 23 is first input to the constant pressure tank 41 for temporary storage, and then input to the inside of the heat exchanger 42 at a constant flow rate through the flow limiting valve, and heat exchange is performed inside the heat exchanger 42 to regenerate steam.

[0051] The return mechanism 5 includes an air storage tank 51, an air supply pipe 52 and a balance pipe 53. The air storage tank 51 is connected to the output end of the heat exchanger 42, one end of the air supply pipe 52 is connected to the air storage tank 51, and the other end of the air supply pipe 52 is connected to the feed port 22; an air pressure balance unit 54 is provided in the middle of the air supply pipe 52, the air supply pipe 52 is connected to the balance pipe 53 through the air pressure balance unit 54, and the end of the balance pipe 53 away from the air pressure balance unit 54 is connected to the air storage tank 51; the air pressure balance unit 54 can keep the steam flow rate transported by the air supply pipe 52 to the feed port 22 constant by controlling the gas flow between the balance pipe 53 and the air storage tank 51.

[0052] The air pressure balancing unit 54 includes an external balancing tube 541, a ventilation mounting plate 542 is arranged in the center of the external balancing tube 541, sealing ring plates 543 are arranged at both ends of the external balancing tube 541, and balancing pistons 545 are connected to both sides of the ventilation mounting plate 542 through balancing springs 544; the air pressure at both ends of the external balancing tube 541 can act on the end of the balancing piston 545 away from the ventilation mounting plate 542 respectively; when the air pressure at both ends of the external balancing tube 541 is unbalanced, the two balancing pistons 545 can be driven at the same time to overcome the elastic force of the corresponding balancing springs 544 and move, and the two balancing pistons 545 can be driven to separate from the corresponding sealing ring plates 543 respectively, so as to connect the two ends of the external balancing tube 541.

[0053] Therefore, when in use, through the setting of the constant pressure tank 41, the constant pressure tank 41 is connected to the heat exchanger 42 through the flow limiting valve, the output pipe 35 and the overflow port 23 are both connected to the constant pressure tank 41, and the liquid output from the output pipe 35 and the overflow port 23 is first input to the constant pressure tank 41 for temporary storage, and then input to the heat exchanger 42 at a constant flow rate through the flow limiting valve to ensure the constant flow of the liquid input to the heat exchanger 42, ensure the heat exchange of the heat exchanger 42 is stable, and then ensure the constant temperature of the steam output from the heat exchanger 42; through the gas storage tank 51, the balance pipe 53 and the air pressure balance unit 54 When the air pressure at both ends of the external balance pipe 541 is unbalanced, the two balance pistons 545 can be driven at the same time to overcome the elastic force of the corresponding balance springs 544 and move, and the two balance pistons 545 can be driven to separate from the corresponding sealing ring plates 543, so as to connect the two ends of the external balance pipe 541, control the gas flow between the balance pipe 53 and the gas storage tank 51, and keep the steam flow rate delivered by the gas pipe 52 to the feed port 22 constant, so as to effectively ensure that the steam flow rate can be within the distillation range of each distillation tower body 2, and can more effectively ensure the distillation inside the distillation tower body 2.

[0054] Embodiment 4:

[0055] A steam compression-based distillation system, using a heat pump distillation device as described in any one of Embodiments 1 to 3, comprises the following steps:

[0056] The liquid to be distilled is input from the reboiler 4 corresponding to the distillation tower body 2 at the head end, and after being converted into steam inside the reboiler 4, it is input to the distillation tower body 2 at the head end through the return mechanism 5 at a constant steam flow rate;

[0057] Inside the distillation tower body 2 at the head end, the steam is condensed and separated to produce condensate and residual steam. The condensate is accumulated at the bottom of the distillation tower body 2 and re-input into the reboiler 4 from the overflow port 23, and the residual steam enters the gas pipeline 31 of the output separation mechanism 3 corresponding to the distillation tower body 2 at the head end;

[0058] The residual steam is compressed into liquid by the compressor 32, and the liquid is distributed by the separator 33 and output to the reflux pipe 34 and the output pipe 35 respectively. The liquid output from the reflux pipe 34 returns to the reboiler 4 corresponding to the distillation tower body 2 at the head end, and the liquid output from the output pipe 35 enters the reboiler 4 corresponding to the next distillation tower body 2;

[0059] After being separated in a plurality of distillation tower bodies 2 in sequence, the distillation product is outputted from the output pipe 35 corresponding to the distillation tower body 2 at the tail end.

[0060] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A heat pump distillation device, characterized in that: include: A fixed support and a plurality of distillation tower bodies arranged in sequence, each of the distillation tower bodies being connected to the top with an output separation mechanism, the distillation tower bodies at the front end being connected to the distillation tower bodies at the rear end through the output separation mechanism, and the distillation tower bodies at the tail end output the product through the output separation mechanism; The output separation mechanism includes a gas pipeline, a compressor, a separator, a reflux pipeline and an output pipeline, and each of the distillation tower bodies is provided with a discharge port at the top; The two ends of the gas pipeline are respectively connected to the discharge port and the compressor, and the steam output from the top of the distillation tower body can be compressed into liquid by the compressor, and the liquid is distributed by the separator and output to the reflux pipeline and the output pipeline respectively; A reboiler and a return mechanism are arranged at the bottom of each distillation tower body, and a feed port and an overflow port are arranged at the bottom of each distillation tower body, and the height of the overflow port is higher than the height of the feed port; The other end of the output pipeline is connected to the feed end of the reboiler corresponding to the next distillation tower body; The other end of the reflux pipeline is connected to the feed end of the reboiler corresponding to the current distillation tower body, the overflow port is connected to the feed end of the reboiler, and the reboiler is connected to the feed port through the return mechanism; The liquid input into the reboiler can be heated into steam again and then injected into the corresponding bottom of the distillation tower through the return mechanism.

2. A heat pump distillation device according to claim 1, characterized in that: The steam temperature output from the discharge port of each distillation tower body is the same, the steam temperature input from the feed port of each distillation tower body is the same, and the steam temperature input from the feed port inside each distillation tower body is higher than the steam temperature output from the discharge port.

3. A heat pump distillation device according to claim 2, characterized in that: Each of the distillation tower bodies is provided with a plurality of liquefied layers in sequence from low to high, and the temperature of each liquefied layer decreases as the height of the position increases; The surface temperatures of the liquefaction layers located at the same height inside the distillation tower bodies are all the same.

4. A heat pump distillation device according to claim 3, characterized in that: Each of the liquefaction layers comprises a connecting layer, a steam port is provided in the center of the connecting layer, the connecting layer is inclined downward from one end close to the inner wall of the distillation tower body toward one end of the steam port, and a plurality of air holes are provided on the surface of the connecting layer; A drainage groove is arranged at one end of the top of the connecting layer plate close to the inner wall of the distillation tower body, and a drainage hole is opened at the bottom of the drainage groove.

5. A heat pump distillation device according to claim 4, characterized in that: A scraper unit is installed inside the steam port, and the scraper unit includes a scraper bracket, a scraper strip, a scraper driving impeller and a water retaining ring plate; The water retaining ring plate is installed at one end of the connecting layer plate close to the steam port, and the water retaining ring plate is inclined downward from the end close to the steam port toward one end of the inner wall of the distillation tower body; The liquid scraping strip goes around the upper and lower side surfaces of the water retaining ring plate, and the liquid scraping strip is in contact with the upper and lower side surfaces of the water retaining ring plate and the lower surface of the connecting layer plate.

6. A heat pump distillation device according to claim 5, characterized in that: The scraper bracket is embedded in the steam port, the scraper driving impeller is rotatably connected to the scraper bracket, and the scraper strip is coaxially fixed to the scraper driving impeller; Under the action of the airflow inside the distillation tower body, the scraper driving impeller rotates and drives the scraper strip to move, resulting in rotation around the axis of the connecting layer plate, scraping the water film attached to the upper and lower sides of the water retaining ring plate and the lower surface of the connecting layer plate.

7. A heat pump distillation device according to claim 1, characterized in that: The reboiler comprises a constant pressure tank and a heat exchanger, the constant pressure tank and the heat exchanger are connected via a flow limiting valve, and the output pipeline and the overflow port are both connected to the constant pressure tank; The liquid output from the output pipe and the overflow port is first input into the constant pressure tank for temporary storage, and then input into the heat exchanger at a constant flow rate through a flow limiting valve, and heat exchange is performed inside the heat exchanger to regenerate steam.

8. A heat pump distillation device according to claim 7, characterized in that: The return mechanism includes a gas storage tank, a gas delivery pipe and a balance pipe, the gas storage tank is connected to the output end of the heat exchanger, one end of the gas delivery pipe is connected to the gas storage tank, and the other end of the gas delivery pipe is connected to the feed port; A gas pressure balance unit is provided in the middle of the gas delivery pipe, the gas delivery pipe is connected with the balance pipe through the gas pressure balance unit, and one end of the balance pipe away from the gas pressure balance unit is connected with the gas storage tank; The gas pressure balancing unit can maintain a constant steam flow rate delivered by the gas delivery pipe to the feed port by controlling the gas flow between the balancing pipe and the gas storage tank.

9. A heat pump distillation device according to claim 8, characterized in that: The air pressure balance unit comprises an external balance pipe, a ventilation mounting plate is arranged in the center of the external balance pipe, sealing ring plates are arranged at both ends of the external balance pipe, and balance pistons are connected to both sides of the ventilation mounting plate through balance springs; The air pressure at both ends of the external balance pipe can act on the end of the balance piston away from the ventilation mounting plate respectively; When the air pressure at both ends of the external balance pipe is unbalanced, the two balance pistons can be driven simultaneously to overcome the elastic force of the corresponding balance springs and move, driving the two balance pistons to separate from the corresponding sealing ring plates, thereby connecting the two ends of the external balance pipe.

10. A distillation system based on steam compression, characterized in that: A heat pump distillation device as claimed in any one of claims 1 to 9 is used, comprising the following steps: The liquid to be distilled is input from the reboiler corresponding to the distillation tower body at the head end, and after being converted into steam inside the reboiler, it is input to the distillation tower body at the head end through the return mechanism at a constant steam flow rate; Inside the distillation tower at the head end, the steam is condensed and separated to produce condensate and residual steam. The condensate is accumulated at the bottom of the distillation tower and re-input into the reboiler from the overflow port, and the residual steam enters the gas pipeline of the output separation mechanism corresponding to the distillation tower at the head end; The residual steam is compressed into liquid by the compressor, and the liquid is distributed by the separator and output to the reflux pipe and the output pipe respectively. The liquid output from the reflux pipe returns to the reboiler corresponding to the distillation tower body at the head end, and the liquid output from the output pipe enters the reboiler corresponding to the next distillation tower body; After being separated by several distillation tower bodies in sequence, the distillation product is output from the output pipeline corresponding to the distillation tower body at the tail end.

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