A mixture step-by-step cooling and separation system and process based on absorption refrigeration

Abstract

The present invention discloses a mixture step-by-step cooling and separation system and process based on absorption refrigeration in the technical field of industrial tail gas treatment, comprising: a generator, a condenser, an evaporation component, an absorption component, a solution pump and a pressure reducing valve, the separation system also comprising: a separation component and a cooler; the evaporation component comprises a low-pressure evaporator and a medium-pressure evaporator; the present invention separates absorption refrigeration from industrial mixture gas cooling, meets the process requirement of separating intermediate products by step-by-step cooling of a certain high-temperature mixture in actual production, and can also recover the heat contained in the intermediate products, realize efficient utilization of energy, and achieve the goal of energy conservation and emission reduction.

Description

Technical Field

[0001] The invention relates to the technical field of industrial tail gas treatment, and in particular to a mixture step-by-step cooling and separation system and process based on absorption refrigeration. Background Art

[0002] In modern industrial production, the separation of mixtures is a vital link and is widely used in many fields such as chemical industry, pharmaceutical industry, and food processing. In actual industrial production, a certain high-temperature mixture needs to be cooled step by step to achieve the purpose of separating intermediate products. For example, the tail gas of a polysilicon reduction furnace is cooled step by step to separate intermediate products, and petroleum refining is cooled step by step to decompose various oil products. In the process of cooling the mixed gas step by step, heat is generally directly exchanged with the mixed gas through a heat exchange medium (such as cooling water), and the heat in the mixed gas is absorbed to cool it down. After absorbing the heat, the heat exchange medium is generally discharged directly, resulting in the inability to use the heat in it, which will cause energy waste. Summary of the invention

[0003] The object of the present invention is to provide a mixture step-by-step cooling and separation system and process based on absorption refrigeration to solve the problem in the above background technology that the heat exchange medium is generally discharged directly after absorbing heat, resulting in the heat contained therein being unable to be utilized, which will cause energy waste.

[0004] To achieve the above object, the present invention provides the following technical solution: a mixture step-by-step cooling and separation system based on absorption refrigeration, comprising: a generator, a condenser, an evaporation component, an absorption component, a solution pump, a pressure reducing valve, a low-pressure expansion valve, a medium-pressure expansion valve and a pressure-raising pump, and the separation system also comprises: a separation component and a cooler;

[0005] The evaporation component includes a low-pressure evaporator and a medium-pressure evaporator; the generator uses the mixture as a heat source to provide cold energy to the low-pressure evaporator and the medium-pressure evaporator, and performs primary cooling on the mixture; the cooler uses circulating water in the condenser to perform secondary cooling on the mixture; the low-pressure evaporator uses the produced cold energy to perform tertiary cooling on the mixture; the separation component is used to separate the liquid produced in each stage of cooling; the medium-pressure evaporator uses the produced cold energy to cool the liquid produced by separation.

[0006] Preferably, the absorption component includes a low-pressure absorber and a medium-pressure absorber, and the separation component includes a three-stage cyclone separator, a first-stage cyclone separator and a second-stage cyclone separator.

[0007] Preferably, the generator utilizes the rich solution to absorb heat in the mixture, performs primary cooling on the mixture, and produces a high-pressure gaseous refrigerant. The condenser utilizes the high-pressure gaseous refrigerant discharged from the generator to exchange heat with circulating water to produce a high-pressure liquid refrigerant, and introduces them into the low-pressure evaporator and the medium-pressure evaporator as cold sources, respectively. The primary cyclone separator is used to perform gas-liquid separation on the primary cooled mixture. The cooler utilizes circulating water to perform secondary cooling on the gas mixture discharged from the primary cyclone separator. The secondary cyclone separator is used to perform gas-liquid separation on the secondary cooled mixture. The low-pressure evaporator is used to perform tertiary cooling on the gas mixture discharged from the secondary cyclone separator. The third-stage cyclone separator is used to perform gas-liquid separation on the tertiary cooled mixture. The medium-pressure evaporator is used to cool the liquid discharged from the primary cyclone separator, the secondary cyclone separator, and the third-stage cyclone separator.

[0008] Preferably, a generating unit is used to replace the generator and the first-stage cyclone separator, a condensing and cooling unit is used to replace the condenser, the cooler and the second-stage cyclone separator, a low-pressure evaporation and absorption unit is used to replace the low-pressure evaporator, the low-pressure absorber and the third-stage cyclone separator, and a medium-pressure evaporation and absorption unit is used to replace the medium-pressure evaporator and the medium-pressure absorber. The generating unit, the condensing and cooling unit, the low-pressure evaporation and absorption unit and the medium-pressure evaporation and absorption unit are fixed tube-sheet heat exchangers whose main structures are composed of a head, a tube box barrel section, a tube sheet, heat exchange tubes and a shell;

[0009] The condensation cooling unit is located above the generating unit, and the low-pressure evaporation absorption unit is located above the medium-pressure evaporation absorption unit.

[0010] Preferably, a first cyclone plate is provided in the generating unit, and the generating unit is used to perform heat exchange between the mixture and the rich solution, so as to cool the mixture in the first stage and decompose the rich solution into high-pressure gaseous refrigerant and lean liquid, and the first cyclone plate is used to perform gas-liquid separation on the first stage cooled mixture;

[0011] The condensation cooling unit comprises a condensation chamber and a cooling chamber, wherein a second cyclone plate is arranged in the cooling chamber, wherein the condensation chamber is used to exchange heat between the high-pressure gaseous refrigerant discharged from the generating unit and the circulating water to produce a high-pressure liquid refrigerant, wherein the cooling chamber is used to exchange heat between the circulating water after use in the condensation chamber and the gas mixture separated by the first cyclone plate, and perform secondary cooling on the gas mixture, wherein the second cyclone plate is used to perform gas-liquid separation on the secondary cooled gas mixture;

[0012] The low-pressure evaporation absorption unit comprises a low-pressure evaporation chamber and a low-pressure absorption chamber, wherein a third cyclone plate is arranged in the low-pressure evaporation chamber, wherein the low-pressure evaporation chamber utilizes the high-pressure liquid refrigerant decompressed by the low-pressure expansion valve to exchange heat with the gas mixture separated by the second cyclone plate, and performs three-stage cooling on the gas mixture, wherein the third cyclone plate is used to perform gas-liquid separation on the three-stage cooled gas mixture, and the low-pressure absorption chamber is used to mix the lean liquid in the generating unit with the low-pressure gaseous refrigerant generated in the low-pressure evaporation chamber to prepare a secondary rich liquid;

[0013] The medium-pressure evaporation absorption unit includes a medium-pressure evaporation chamber and a medium-pressure absorption chamber. The medium-pressure evaporation chamber uses the high-pressure liquid refrigerant reduced in pressure by the medium-pressure expansion valve to cool the liquid separated by the first cyclone plate, the second cyclone plate, and the third cyclone plate. The medium-pressure absorption chamber is used to mix the secondary rich liquid pressurized by the pressure-boosting pump with the medium-pressure gaseous refrigerant generated in the medium-pressure evaporation chamber to produce a rich liquid. The circulating water inlet and outlet of the medium-pressure absorption chamber are respectively connected to the circulating water outlet of the low-pressure absorption chamber and the circulating water inlet of the condensing chamber.

[0014] Preferably, the heat exchange tubes of the low-pressure evaporation chamber and the low-pressure absorption chamber are separated by a first liquid baffle plate;

[0015] The heat exchange tubes of the medium-pressure evaporation chamber and the medium-pressure absorption chamber are separated by a second liquid baffle plate.

[0016] Preferably, two baffle plates are provided in the medium-pressure evaporation chamber to separate the heat exchange tube inlet and outlet of the medium-pressure evaporation chamber into three inlet and outlets separated from each other.

[0017] Preferably, a baffle is provided in the shell of the cooling chamber.

[0018] Preferably, a mixture step-by-step cooling separation process based on absorption refrigeration, using the above-mentioned mixture step-by-step cooling separation system based on absorption refrigeration, comprises the following steps:

[0019] The gaseous mixture to be separated is introduced into the generator as a heat source to heat the high-pressure rich liquid in the generator to produce a high-pressure gaseous refrigerant, and the gaseous mixture itself is cooled to form a first gas-liquid mixture;

[0020] The high-pressure gaseous refrigerant enters the condenser and is condensed into high-pressure liquid refrigerant by circulating water. It is then divided into two paths. One path is decompressed by the low-pressure expansion valve and enters the low-pressure evaporator. The other path is decompressed by the medium-pressure expansion valve and enters the medium-pressure evaporator.

[0021] The first-stage cyclone separator separates the first gas-liquid mixture, and the liquid produced by the separation enters the medium-pressure evaporator to be cooled and then discharged, and the remaining gas enters the cooler to be cooled by circulating water to form a second gas-liquid mixture;

[0022] The second gas-liquid mixture enters the secondary cyclone separator for separation, the liquid produced by the separation enters the medium-pressure evaporator to be cooled and then discharged, and the remaining gas enters the low-pressure evaporator to be cooled to form a third gas-liquid mixture;

[0023] The third gas-liquid mixture enters the three-stage cyclone separator for separation, the liquid produced by the separation enters the medium-pressure evaporator to be cooled and then discharged, and the remaining gas is directly discharged.

[0024] Preferably, a mixture step-by-step cooling separation process based on absorption refrigeration, further utilizing the above-mentioned mixture step-by-step cooling separation system based on absorption refrigeration, comprises the following steps:

[0025] The gaseous mixture to be separated is introduced into the generating unit as a heat source to heat the high-pressure rich liquid inside the generating unit to produce a high-pressure gaseous refrigerant, and the gaseous mixture itself is cooled to form a first gas-liquid mixture;

[0026] The high-pressure gaseous refrigerant enters the condensing chamber, and after being condensed into high-pressure liquid refrigerant by circulating water, it is divided into two paths. One path is decompressed by the low-pressure expansion valve and enters the low-pressure evaporation chamber, and the other path is decompressed by the medium-pressure expansion valve and enters the medium-pressure evaporation chamber.

[0027] The first gas-liquid mixture is separated by the first cyclone plate, so that the separated liquid enters the medium-pressure evaporation chamber to be cooled and then discharged, and the remaining gas enters the cooling chamber to be cooled by circulating water to form a second gas-liquid mixture;

[0028] The second gas-liquid mixture is separated by the second cyclone plate, and the separated liquid enters the medium-pressure evaporation chamber to be cooled and then discharged, and the remaining gas enters the low-pressure evaporation chamber to be cooled to form a third gas-liquid mixture;

[0029] The third gas-liquid mixture is separated by the third cyclone plate, and the liquid produced by the separation enters the medium-pressure evaporation chamber and is cooled and then discharged, and the remaining gas is directly discharged.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. Embedding the absorption refrigeration process into the industrial mixed gas cooling and separation process not only meets the process requirements of actual production that a certain high-temperature mixture needs to be cooled step by step to separate the intermediate product, but also can recover the heat contained in the intermediate product, realize the efficient use of energy, and achieve the goal of energy conservation and emission reduction;

[0032] 2. Integrate all the equipment used into one device, which reduces the cost of equipment and pipelines, greatly reduces the footprint of the unit, and facilitates later installation and transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the separation system structure of the present invention;

[0034] Figure 2 This is a schematic diagram of the connection structure between the generating unit and the condensing cooling unit of the present invention;

[0035] Figure 3 For the present invention Figure 2 Schematic diagram of the structure of the middle aa surface;

[0036] Figure 4 For the present invention Figure 2 Schematic diagram of the structure of the middle bb surface;

[0037] Figure 5 For the present invention Figure 4 Schematic diagram of the structure of the middle cc surface;

[0038] Figure 6 For the present invention Figure 4 Schematic diagram of the structure of the middle dd surface;

[0039] Figure 7 For the present invention Figure 4 Schematic diagram of the middle ee surface structure;

[0040] Figure 8 For the present invention Figure 4 Schematic diagram of the structure of the middle ff surface;

[0041] Fig. 9 For the present invention Figure 4 Schematic diagram of the middle gg surface structure.

[0042] In the figure: 1. generator; 2. condenser; 3. low-pressure evaporator; 4. medium-pressure evaporator; 5. three-stage cyclone separator; 6. low-pressure expansion valve; 7. medium-pressure expansion valve; 8. first-stage cyclone separator; 9. cooler; 10. second-stage cyclone separator; 11. low-pressure absorber; 12. medium-pressure absorber; 13. pressure-boosting pump; 14. solution pump; 15. pressure-reducing valve; 16. generating unit; 161. first shell; 162. first pipe box; 163. first heat exchange tube; 164. first cyclone plate; 17. condensation cooling unit; 171. condensation chamber; 172. cooling chamber; 173. second shell; 174. second pipe box; 175. second heat exchange tube; 176 , baffle; 177, second swirl plate; 178, first partition; 18, low-pressure evaporation absorption unit; 181, low-pressure evaporation chamber; 182, low-pressure absorption chamber; 183, second partition; 184, first liquid baffle; 185, third shell; 186, third pipe box; 187, third heat exchange tube; 188, third swirl plate; 189, first partition; 19, medium-pressure evaporation absorption unit; 191, medium-pressure evaporation chamber; 192, medium-pressure absorption chamber; 193, third partition; 194, second liquid baffle; 195, fourth shell; 196, fourth pipe box; 197, fourth heat exchange tube; 198, second partition; 199, barrier plate; 20, base. DETAILED DESCRIPTION

[0043] 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.

[0044] In this embodiment, the gaseous mixture to be separated is composed of four components. For example, the gaseous mixture to be separated is the tail gas of a polysilicon reduction furnace (A+B+C+D), where A is trichlorosilane, B is chlorosilane, C is hydrogen chloride, and D is hydrogen.

[0045] Example 1

[0046] See also Figure 1 , a mixture step-by-step cooling and separation system based on absorption refrigeration, comprising: a generator 1, a condenser 2, an evaporation component, an absorption component, a solution pump 14, a pressure reducing valve 15, a separation component and a cooler 9, a low-pressure expansion valve 6, a medium-pressure expansion valve 7 and a pressure-raising pump 13;

[0047] Among them, see Figure 1The evaporation component includes a low-pressure evaporator 3 and a medium-pressure evaporator 4; the absorption component includes a low-pressure absorber 11 and a medium-pressure absorber 12; the separation component includes a three-stage cyclone separator 5, a first-stage cyclone separator 8 and a second-stage cyclone separator 10.

[0048] See also Figure 1 The heat source outlet of the generator 1 is communicated with the primary cyclone separator 8, the high-pressure gaseous refrigerant outlet of the generator 1 is communicated with the high-pressure gaseous refrigerant inlet of the condenser 2, the lean liquid outlet of the generator 1 is communicated with the lean liquid inlet of the low-pressure absorber 11 through the pressure reducing valve 15, the rich liquid inlet of the generator 1 is communicated with the rich liquid outlet of the medium-pressure absorber 12 through the solution pump 14, the liquid outlet of the primary cyclone separator 8 is communicated with the medium-pressure evaporator 4, the gas outlet of the primary cyclone separator 8 is communicated with the cooler 9, the outlet of the cooler 9 is communicated with the inlet of the secondary cyclone separator 10, the cooler 9 is communicated with the circulation outlet of the condenser 2, the circulating water inlet of the condenser 2 is communicated with the circulating water outlet of the medium-pressure absorber 12, and a high-pressure liquid refrigerant outlet of the condenser 2 is communicated with the low-pressure evaporator 4 through the low-pressure expansion valve 6. 3, another high-pressure liquid refrigerant outlet of the condenser 2 is communicated with the medium-pressure liquid refrigerant inlet of the medium-pressure evaporator 4 through the medium-pressure expansion valve 7, the liquid outlet of the secondary cyclone separator 10 is communicated with the medium-pressure evaporator 4, the gas outlet of the secondary cyclone separator 10 is communicated with the low-pressure evaporator 3, the low-pressure evaporator 3 is communicated with the tertiary cyclone separator 5, the liquid outlet of the tertiary cyclone separator 5 is communicated with the medium-pressure evaporator 4, the low-pressure gaseous refrigerant outlet of the low-pressure evaporator 3 is communicated with the low-pressure gaseous refrigerant inlet of the low-pressure absorber 11, the secondary rich liquid outlet of the low-pressure absorber 11 is communicated with the secondary rich liquid inlet of the medium-pressure absorber 12 through the pressure-boosting pump 13, and the medium-pressure gaseous refrigerant inlet of the medium-pressure absorber 12 is communicated with the medium-pressure gaseous refrigerant outlet of the medium-pressure evaporator 4.

[0049] A mixture step-by-step cooling separation process based on absorption refrigeration comprises the following steps:

[0050] The gaseous mixture (A+B+C+D) to be separated is introduced into the generator 1 as a heat source to heat the high-pressure rich liquid delivered by the solution pump 14, so that most of the low-boiling-point refrigerant in the high-pressure rich liquid is desorbed to become a high-pressure gaseous refrigerant. The high-pressure rich liquid with the refrigerant removed becomes a high-pressure lean liquid, and the gaseous mixture (A+B+C+D) itself is cooled to form a first gas-liquid mixture {the gaseous A with the highest dew point is condensed into liquid, and the high-temperature gaseous mixture (A+B+C+D) absorbs heat through the generator 1 and becomes a high-temperature gaseous mixture (B+C+D) + liquid A};

[0051] The high-pressure gaseous refrigerant enters the condenser 2, and after being condensed into high-pressure liquid refrigerant by circulating water, it is divided into two paths. One path is decompressed into low-pressure liquid refrigerant by the low-pressure expansion valve 6 and enters the low-pressure evaporator 3. The other path is decompressed into medium-pressure liquid refrigerant by the medium-pressure expansion valve 7 and enters the medium-pressure evaporator 4.

[0052] The high-temperature gaseous mixture (B+C+D) and liquid A enter the primary cyclone separator 8 and are separated into a high-temperature gaseous mixture (B+C+D) and a high-temperature liquid A. The high-temperature liquid A enters the medium-pressure evaporator 4. The high-temperature gaseous mixture (B+C+D) enters the cooler 9 and is cooled by circulating water to form a second gas-liquid mixture {the gaseous B with a higher dew point is condensed into liquid, and the high-temperature gaseous mixture (B+C+D) absorbs heat through the cooler 9 and becomes a high-temperature gaseous mixture (C+D) + liquid B};

[0053] The high-temperature gaseous mixture (C+D) and liquid B enter the secondary cyclone separator 10 and are separated into a high-temperature gaseous mixture (C+D) and a high-temperature liquid B. The high-temperature liquid B enters the medium-pressure evaporator 4. The high-temperature gaseous mixture (C+D) enters the low-pressure evaporator 3 and is cooled by the low-pressure liquid refrigerant in the low-pressure evaporator 3 to form a third gas-liquid mixture {the gaseous C with the second lowest dew point is condensed into liquid, and the high-temperature gaseous mixture (C+D) absorbs heat through the low-pressure evaporator 3 to become a high-temperature gaseous D+liquid C};

[0054] High-temperature gaseous state D + liquid state C enters the three-stage cyclone separator 5, and is separated into gaseous state D (final product) and high-temperature liquid state C. High-temperature liquid state C enters the medium-pressure evaporator 4, and absorbs heat and cools down again with the high-temperature liquid state A and high-temperature liquid state B that entered previously, and becomes normal-temperature liquid state A, normal-temperature liquid state B and normal-temperature liquid state C that are discharged from the medium-pressure evaporator 4. Gaseous state D is discharged from the three-stage cyclone separator 5, and the medium-pressure liquid refrigerant becomes medium-pressure gaseous refrigerant.

[0055] The low-pressure liquid refrigerant entering the low-pressure evaporator 3 becomes a low-pressure gaseous refrigerant after absorbing heat and enters the low-pressure absorber 11; the high-pressure lean liquid discharged from the generator 1 is reduced in pressure by the reducing valve 15 to become a low-pressure lean liquid, enters the low-pressure absorber 11, is mixed and absorbed with the low-pressure gaseous refrigerant coming out of the low-pressure evaporator 3, and becomes a low-pressure secondary rich liquid. The low-pressure secondary rich liquid is pressurized by the pressure-boosting pump 13 to become a medium-pressure secondary rich liquid. The medium-pressure secondary rich liquid enters the medium-pressure absorber 12, is mixed and absorbed with the medium-pressure gaseous refrigerant coming out of the medium-pressure evaporator 4, and becomes a medium-pressure rich liquid. The medium-pressure rich liquid is pressurized by the solution pump 14 and then sent to the generator 1 to continue the cycle.

[0056] It should be noted that the normal temperature circulating water enters the low-pressure absorber 11, the medium-pressure absorber 12, the condenser 2 and the cooler 9 in series in sequence; it is first used to absorb the mixed heat generated during the absorption process of the low-pressure absorber 11 and the medium-pressure absorber 12, and then used for condensation and cooling in the condenser 2 and the cooler 9; the temperature of the circulating water increases step by step, and finally flows out of the cooler 9 and becomes high-temperature circulating water, which can be used for heating.

[0057] Example 2

[0058] See also Figure 2 , using a generating unit 16 to replace the generator 1 and the first-stage cyclone separator 8, using a condensing and cooling unit 17 to replace the condenser 2, the cooler 9 and the second-stage cyclone separator 10, using a low-pressure evaporation and absorption unit 18 to replace the low-pressure evaporator 3, the low-pressure absorber 11 and the third-stage cyclone separator 5, using a medium-pressure evaporation and absorption unit 19 to replace the medium-pressure evaporator 4 and the medium-pressure absorber 12, the generating unit 16, the condensing and cooling unit 17, the low-pressure evaporation and absorption unit 18 and the medium-pressure evaporation and absorption unit 19 are fixed tube-sheet heat exchangers whose main structures are composed of a head, a tube box barrel section, a tube sheet, a heat exchange tube and a shell;

[0059] It should be noted that the equipment is integrated together to reduce the overall size of the equipment. For small and medium-sized units that can meet transportation requirements, all assembly of the unit can be completed in the equipment manufacturing plant, including pipeline installation and electrical instrument commissioning, etc.; and then the whole unit is transported to the customer site, which can be quickly delivered and put into production; for large and extra-large units that exceed the transportation limit, all assembly of the unit can be completed in the equipment manufacturing plant first, and then the units are transported to the customer site in separate or partial separate parts, and quickly assembled on site; the construction period can be shortened and the construction cost can be greatly reduced.

[0060] Among them, see Figure 2 and Figure 3 The generating unit 16 includes a first shell 161 and two first pipe boxes 162 respectively arranged at both ends of the first shell 161. A first heat exchange tube 163 is arranged in the inner cavity of the first shell 161, and the first heat exchange tube 163 connects the two first pipe boxes 162; a high-pressure rich liquid inlet, a high-pressure gaseous refrigerant outlet and a high-pressure lean liquid outlet are arranged on the first shell 161, a heat source inlet is arranged on one first pipe box 162, and two outlets are arranged on the other first pipe box 162, and a first swirl plate 164 is arranged in the first pipe box 162;

[0061] See also Figure 2 and Figure 3The condensing cooling unit 17 includes a second shell 173 and two second pipe boxes 174 respectively arranged at both ends of the second shell 173. A second heat exchange pipe 175 is arranged in the inner cavity of the second shell 173. The second heat exchange pipe 175 is used to connect the two second pipe boxes 174. A first partition 178 is arranged in the condensing cooling unit 17. The first partition 178 is used to divide the inner cavity of the condensing cooling unit 17 into a condensing cavity 171 and a cooling cavity 172. The second shell 173 of the condensing cavity 171 is provided with a high-pressure liquid refrigerant outlet and a high-pressure gas outlet for the generating unit 16. A high-pressure gaseous refrigerant inlet is connected to a gaseous refrigerant outlet, a circulating water inlet and a circulating water outlet are respectively provided on the two second pipe boxes 174 of the condensing chamber 171, a circulating water inlet and a circulating water outlet for communicating with the circulating water outlet of the condensing chamber 171 are provided on the second shell 173 of the cooling chamber 172, a second pipe box 174 of the cooling chamber 172 is provided with an inlet for communicating with an outlet of the generating unit 16, another second pipe box 174 of the cooling chamber 172 is provided with two outlets, and a second swirl plate 177 is provided in the second pipe box 174;

[0062] See also Figure 2 , Figure 4 , Figure 5 and Figure 7 The low-pressure evaporation absorption unit 18 includes a third shell 185 and two third pipe boxes 186 respectively arranged at both ends of the third shell 185. A third heat exchange tube 187 is arranged in the inner cavity of the third shell 185. The third heat exchange tube 187 is used to connect the two third pipe boxes 186. A first partition plate is arranged in the inner cavity of the low-pressure evaporation absorption unit 18. The first partition plate is used to divide the inner cavity of the low-pressure evaporation absorption unit 18 into a low-pressure evaporation chamber 181 and a low-pressure absorption chamber 182. A low-pressure liquid refrigerant inlet and a low-pressure gaseous refrigerant outlet are arranged on the third shell 185 of the low-pressure evaporation chamber 181. The low-pressure liquid refrigerant inlet is connected to the high-pressure liquid refrigerant outlet of the condensation chamber 171 through the low-pressure expansion valve 6. , a third pipe box 186 of the low-pressure evaporation chamber 181 is provided with an inlet for communicating with an outlet of the cooling chamber 172, another third pipe box 186 of the low-pressure evaporation chamber 181 is provided with two outlets and a third swirl plate 188 is provided in the third pipe box 186, a low-pressure lean liquid inlet, a low-pressure gaseous refrigerant inlet and a low-pressure secondary rich liquid outlet are provided on the third shell 185 of the low-pressure absorption chamber 182, the low-pressure lean liquid inlet is communicated with the high-pressure lean liquid outlet of the generating unit 16 through the pressure reducing valve 15, the low-pressure gaseous refrigerant inlet is communicated with the low-pressure gaseous refrigerant outlet of the low-pressure evaporation chamber 181, and a circulating water inlet and a circulating water outlet are respectively provided on the two third pipe boxes 186 of the low-pressure absorption chamber 182;

[0063] See also Figure 2 , Figure 4 , Figure 6 , Figure 8 and Fig. 9 The medium-pressure evaporation absorption unit 19 includes a fourth shell 195 and two fourth pipe boxes 196 respectively arranged at both ends of the fourth shell 195. A fourth heat exchange tube 197 is arranged in the inner cavity of the fourth shell 195, and the fourth heat exchange tube 197 is used to connect the two fourth pipe boxes; a second dividing plate is arranged in the inner cavity of the medium-pressure evaporation absorption unit 19, and the second dividing plate is used to divide the inner cavity of the medium-pressure evaporation absorption unit 19 into a medium-pressure evaporation chamber 191 and a medium-pressure absorption chamber 192; a medium-pressure liquid refrigerant inlet and a medium-pressure gaseous refrigerant outlet are arranged on the fourth shell 195 of the medium-pressure evaporation chamber 191, and the medium-pressure liquid refrigerant inlet is connected to the high-pressure liquid refrigerant outlet of the condensing chamber 171 through the medium-pressure expansion valve 7, and an inlet and an outlet are respectively arranged on the two fourth pipe boxes 196 of the medium-pressure evaporation chamber 191, and the inlet of the medium-pressure evaporation chamber 191 is divided into The medium-pressure secondary rich liquid inlet, the medium-pressure gaseous refrigerant inlet and the medium-pressure rich liquid outlet are respectively connected with the generating unit 16, the cooling chamber 172 and an outlet of the low-pressure evaporation chamber 181; the medium-pressure secondary rich liquid inlet is connected with the low-pressure secondary rich liquid outlet of the low-pressure absorption chamber 182 through the pressure-boosting pump 13; the medium-pressure gaseous refrigerant inlet is connected with the medium-pressure gaseous refrigerant outlet of the medium-pressure evaporation chamber 191; the medium-pressure rich liquid outlet is connected with the high-pressure rich liquid inlet of the generating unit 16 through the solution pump 14; the two fourth pipe boxes 196 of the medium-pressure absorption chamber 192 are respectively provided with a circulating water inlet and a circulating water outlet; the circulating water inlet of the medium-pressure absorption chamber 192 is connected with the circulating water outlet of the low-pressure absorption chamber 182; the circulating water outlet of the medium-pressure absorption chamber 192 is connected with the circulating water inlet of the condensing chamber 171.

[0064] In this embodiment, as a further optimized solution, please refer to Figure 2 , Figure 3 and Figure 4 The separator also includes a base 20, the generating unit 16 and the medium-pressure evaporation absorption unit 19 are both arranged on the base 20, the condensation cooling unit 17 is arranged on the top of the generating unit 16, and the low-pressure evaporation absorption unit 18 is arranged on the top of the medium-pressure evaporation absorption unit 19.

[0065] In this embodiment, as a further optimized solution, please refer to Figure 2 , Figure 5 and Figure 6The first partition plate includes a second partition plate 183 disposed in the third shell 185 and a first partition plate 189 disposed in the third pipe box 186. The second partition plate 183 is provided with a first through hole, and the first through hole is the low-pressure gas refrigerant outlet of the low-pressure evaporation chamber 181 and the low-pressure gas refrigerant inlet of the low-pressure absorption chamber 182. The first through hole is provided with a first liquid baffle plate 184; the second partition plate includes a third partition plate 193 disposed in the fourth shell 195 and a second partition plate 198 disposed in the fourth pipe box 196. The third partition plate 193 is provided with a second through hole. The second through-port is the medium-pressure gaseous refrigerant outlet of the medium-pressure evaporation chamber 191 and the medium-pressure gaseous refrigerant inlet of the medium-pressure absorption chamber 192, and a second liquid baffle 194 is arranged in the second through-port; the first through-port is arranged so that the low-pressure gaseous refrigerant outlet of the low-pressure evaporation chamber 181 is the low-pressure gaseous refrigerant inlet of the low-pressure absorption chamber 182; the second through-port is arranged so that the medium-pressure gaseous refrigerant outlet of the medium-pressure evaporation chamber 191 is the medium-pressure gaseous refrigerant inlet of the medium-pressure absorption chamber 192, so that less piping can be used when connecting the interfaces, thereby reducing the volume of the equipment.

[0066] In this embodiment, as a further optimized solution, please refer to Figure 8 and Fig. 9 Two baffles 199 are provided in the inner cavity of the fourth tube box 196 of the medium-pressure evaporation chamber 191 to divide the inner cavity of the fourth tube box 196 into three mutually isolated cavities, so that the liquid ABC entering the inside of the medium-pressure evaporation chamber 191 can be separated and not mixed together.

[0067] In this embodiment, as a further optimized solution, please refer to Figure 3 A plurality of baffles 176 are provided in the inner cavity of the second shell 173 of the cooling cavity 172; the circulating water is guided by the plurality of baffles 176 so that the circulating water flows in a curved manner inside the second shell 173, thereby increasing the contact time between the circulating water and the second heat exchange tube 175 in the cooling cavity 172 and improving the heat exchange efficiency.

[0068] It should be noted that a spray assembly (the spray assembly includes a pipeline and a plurality of nozzles arranged on the pipeline) is installed on the top of the inner cavity of the first shell 161 of the generating unit 16, and the spray assembly is connected to the high-pressure rich liquid inlet; a spray assembly is installed on the top of the inner cavity of the third shell 185 of the low-pressure evaporation chamber 181, and the spray assembly is connected to the low-pressure liquid refrigerant inlet, and a spray assembly is installed on the top of the inner cavity of the third shell 185 of the low-pressure absorption chamber 182, and the spray assembly is connected to the low-pressure lean liquid inlet; a spray assembly is installed on the top of the inner cavity of the fourth shell 195 of the medium-pressure evaporation chamber 191, and the spray assembly is connected to the medium-pressure liquid refrigerant inlet; a spray assembly is installed on the top of the inner cavity of the fourth shell 195 of the medium-pressure evaporation chamber 192, and the spray assembly is connected to the medium-pressure secondary rich liquid inlet.

[0069] A mixture step-by-step cooling separation process based on absorption refrigeration comprises the following steps:

[0070] The high-temperature gaseous mixture (A+B+C+D) is introduced into the first heat exchange tube 163 of the generating unit 16 as a heat source to heat the high-pressure rich liquid delivered by the solution pump 14 in the first shell 161, so that most of the low-boiling-point refrigerant in the high-pressure rich liquid is desorbed to become a high-pressure gaseous refrigerant. After the refrigerant is removed, the high-pressure rich liquid becomes a high-pressure lean liquid, and the gaseous mixture itself is cooled to form a first gas-liquid mixture {the high-temperature gaseous mixture (A+B+C+D) is cooled by heat absorption in the generating unit 16, and the gaseous A with the highest dew point is condensed into liquid, and the high-temperature gaseous mixture (A+B+C+D) becomes a high-temperature gaseous mixture (B+C+D) + liquid A after passing through the generating unit 16};

[0071] The generated high-pressure gaseous refrigerant enters the interior of the second shell 173 of the condensing chamber 171, is condensed by the circulating water in the second heat exchange tube 175 into high-pressure liquid refrigerant and is discharged. The high-pressure liquid refrigerant flowing out of the second shell 173 of the condensing chamber 171 is divided into two paths, one path is decompressed into low-pressure liquid refrigerant by the low-pressure expansion valve 6 and enters the third shell 185 of the low-pressure evaporation chamber 181, and the other path is decompressed into medium-pressure liquid refrigerant by the medium-pressure expansion valve 7 and enters the fourth shell 195 of the medium-pressure evaporation chamber 191;

[0072] The high-temperature gaseous mixture (B+C+D) and liquid A enter the first pipe box 162 of the generating unit 16. The built-in first cyclone plate 164 forces the gas-liquid mixture to generate a cyclone, so that the gas-liquid two phases are separated and separated into the high-temperature gaseous mixture (B+C+D) and the high-temperature liquid A. The high-temperature liquid A enters the fourth heat exchange tube 197 of the medium-pressure evaporation chamber 191. The high-temperature gaseous mixture (B+C+D) enters the second heat exchange tube 175 of the cooling chamber 172. The second gas-liquid mixture is cooled by the circulating water in the second shell 173 of the cooling chamber 172 {the gaseous B with a higher dew point is condensed into liquid, and the high-temperature gaseous mixture (B+C+D) becomes the high-temperature gaseous mixture (C+D) + liquid B after passing through the cooling chamber 172};

[0073] The high-temperature gaseous mixture (C+D) and liquid B enter the second pipe box 174 of the cooling chamber 172. The built-in second cyclone plate 177 forces the gas-liquid mixture to generate a cyclone, so that the gas-liquid two phases are separated and separated into the high-temperature gaseous mixture (C+D) and the high-temperature liquid B. The high-temperature liquid B enters the fourth heat exchange tube 197 of the medium-pressure evaporation chamber 191, and the high-temperature gaseous mixture (C+D) enters the third heat exchange tube 187 of the low-pressure evaporation chamber 181. The low-pressure liquid refrigerant that enters absorbs heat and cools to form a third gas-liquid mixture {the gaseous C with the second lowest dew point is condensed into liquid, and the high-temperature gaseous mixture (C+D) passes through the low-pressure evaporation chamber 181 and becomes high-temperature gaseous D+liquid C};

[0074] The high-temperature gaseous state D and liquid state C enter the third pipe box 186 of the low-pressure evaporation chamber 181. The built-in third swirl plate 188 forces the gas-liquid mixture to generate a swirl flow, so that the gas-liquid two phases are separated and separated into gaseous state D (final product) and high-temperature liquid state C. The high-temperature liquid state C enters the fourth heat exchange tube 197 of the medium-pressure evaporation chamber 191, and together with the high-temperature liquid state A and high-temperature liquid state B that entered previously, is again absorbed by the medium-pressure liquid refrigerant in the fourth shell 195 of the medium-pressure evaporation chamber 191 and cooled down by heat, and becomes normal-temperature liquid state A, normal-temperature liquid state B and normal-temperature liquid state C before being discharged.

[0075] The low-pressure liquid refrigerant entering the third shell 185 of the low-pressure evaporation chamber 181 absorbs heat and becomes a low-pressure gaseous refrigerant, and the low-pressure gaseous refrigerant enters the third shell 185 of the low-pressure absorption chamber 182; the high-pressure lean liquid discharged from the generating unit 16 is reduced in pressure by the reducing valve 15 to become a low-pressure lean liquid, and enters the third shell 185 of the low-pressure absorption chamber 182, where it is mixed and absorbed with the low-pressure gaseous refrigerant coming out of the low-pressure evaporation chamber 181 to become a low-pressure secondary rich liquid; the low-pressure secondary rich liquid is pressurized by the pressure-boosting pump 13 to become a medium-pressure secondary rich liquid, and then enters the fourth shell 195 of the medium-pressure absorption chamber 192, where it is mixed and absorbed with the medium-pressure gaseous refrigerant coming out of the medium-pressure evaporation chamber 191 to become a medium-pressure rich liquid, and the medium-pressure rich liquid is pressurized by the solution pump 14 and sent to the generating unit 16 to continue the circulation work.

[0076] It should be noted that the normal temperature circulating water is first used to absorb the mixed heat generated during the absorption process of the low-pressure absorption chamber 182 and the medium-pressure absorption chamber 192, and then used for condensation and cooling in the condensation chamber 171 and the cooling chamber 172; the temperature of the circulating water increases step by step, and finally flows out of the cooling chamber 172 and becomes high-temperature circulating water, which can be used for heating.

[0077] 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 mixture step-by-step cooling and separation system based on absorption refrigeration, comprising: Generator (1), condenser (2), evaporation component, absorption component, solution pump (14), pressure reducing valve (15), low-pressure expansion valve (6), medium-pressure expansion valve (7) and pressure-raising pump (13), characterized in that: the separation system also includes: a separation component and a cooler (9); The evaporation component comprises a low-pressure evaporator (3) and a medium-pressure evaporator (4); the generator (1) uses the mixture as a heat source to provide cold energy to the low-pressure evaporator (3) and the medium-pressure evaporator (4), and performs primary cooling on the mixture; the cooler (9) uses circulating water in the condenser (2) to perform secondary cooling on the mixture; the low-pressure evaporator (3) uses the generated cold energy to perform tertiary cooling on the mixture; the separation component is used to separate the liquid generated by each stage of cooling; and the medium-pressure evaporator (4) uses the generated cold energy to cool the liquid generated by separation.

2. A mixture step-by-step cooling and separation system based on absorption refrigeration according to claim 1, characterized in that: The absorption component comprises a low-pressure absorber (11) and a medium-pressure absorber (12), and the separation component comprises a third-stage cyclone separator (5), a first-stage cyclone separator (8) and a second-stage cyclone separator (10).

3. A mixture step-by-step cooling and separation system based on absorption refrigeration according to claim 2, characterized in that: The generator (1) uses the rich solution to absorb heat in the mixture, performs primary cooling on the mixture, and produces a high-pressure gaseous refrigerant. The condenser (2) uses the high-pressure gaseous refrigerant discharged from the generator (1) to exchange heat with circulating water to produce a high-pressure liquid refrigerant, and introduces the high-pressure liquid refrigerant into the low-pressure evaporator (3) and the medium-pressure evaporator (4) as a cold source. The primary cyclone separator (8) is used to perform gas-liquid separation on the primary cooled mixture. The cooler (9) uses circulating water to perform secondary cooling on the gas mixture discharged from the primary cyclone separator (8). The secondary cyclone separator (10) is used to perform gas-liquid separation on the secondary cooled mixture. The low-pressure evaporator (3) is used to perform tertiary cooling on the gas mixture discharged from the secondary cyclone separator (10). The tertiary cyclone separator (5) is used to perform gas-liquid separation on the tertiary cooled mixture. The medium-pressure evaporator (4) is used to cool the liquid discharged from the primary cyclone separator (8), the secondary cyclone separator (10), and the tertiary cyclone separator (5).

4. A mixture step-by-step cooling and separation system based on absorption refrigeration according to claim 3, characterized in that: A generating unit (16) is used to replace the generator (1) and the first-stage cyclone separator (8); a condensing and cooling unit (17) is used to replace the condenser (2), the cooler (9) and the second-stage cyclone separator (10); a low-pressure evaporation and absorption unit (18) is used to replace the low-pressure evaporator (3), the low-pressure absorber (11) and the third-stage cyclone separator (5); and a medium-pressure evaporation and absorption unit (19) is used to replace the medium-pressure evaporator (4) and the medium-pressure absorber (12); the generating unit (16), the condensing and cooling unit (17), the low-pressure evaporation and absorption unit (18) and the medium-pressure evaporation and absorption unit (19) are fixed tube sheet heat exchangers whose main structures are composed of a head, a tube box barrel section, a tube sheet, heat exchange tubes and a shell; The condensation cooling unit (17) is located above the generating unit (16), and the low-pressure evaporation absorption unit (18) is located above the medium-pressure evaporation absorption unit (19).

5. A mixture step-by-step cooling and separation system based on absorption refrigeration according to claim 4, characterized in that: A first cyclone plate (164) is provided in the generating unit (16), and the generating unit (16) is used to perform heat exchange between the mixture and the rich solution, so as to perform primary cooling of the mixture and decompose the rich solution into a high-pressure gaseous refrigerant and a lean liquid, and the first cyclone plate (164) is used to perform gas-liquid separation on the primary cooled mixture; The condensation cooling unit (17) comprises a condensation chamber (171) and a cooling chamber (172); a second cyclone plate (177) is provided in the cooling chamber (172); the condensation chamber (171) is used to exchange heat between the high-pressure gaseous refrigerant discharged from the generating unit (16) and circulating water to produce high-pressure liquid refrigerant; the cooling chamber (172) is used to exchange heat between the circulating water used in the condensation chamber (171) and the gas mixture separated by the first cyclone plate (164) to perform secondary cooling on the gas mixture; and the second cyclone plate (177) is used to perform gas-liquid separation on the secondary cooled gas mixture; The low-pressure evaporation absorption unit (18) comprises a low-pressure evaporation chamber (181) and a low-pressure absorption chamber (182); a third swirl plate (188) is provided in the low-pressure evaporation chamber (181); the low-pressure evaporation chamber (181) uses the high-pressure liquid refrigerant reduced in pressure by the low-pressure expansion valve (6) to exchange heat with the gas mixture separated by the second swirl plate (177) to perform three-stage cooling on the gas mixture; the third swirl plate (188) is used to perform gas-liquid separation on the three-stage cooled gas mixture; and the low-pressure absorption chamber (182) is used to mix the lean liquid in the generating unit (16) with the low-pressure gaseous refrigerant generated in the low-pressure evaporation chamber (181) to produce a secondary rich liquid; The medium-pressure evaporation absorption unit (19) comprises a medium-pressure evaporation chamber (191) and a medium-pressure absorption chamber (192). The medium-pressure evaporation chamber (191) uses the high-pressure liquid refrigerant reduced in pressure by the medium-pressure expansion valve (7) to cool the liquid separated by the first swirl plate (164), the second swirl plate (177), and the third swirl plate (188). The medium-pressure absorption chamber (192) is used to mix the secondary rich liquid pressurized by the pressure-boosting pump (13) with the medium-pressure gaseous refrigerant generated in the medium-pressure evaporation chamber (191) to produce a rich liquid. The circulating water inlet and outlet of the medium-pressure absorption chamber (192) are respectively connected to the circulating water outlet of the low-pressure absorption chamber (182) and the circulating water inlet of the condensing chamber (171).

6. A mixture step-by-step cooling and separation system based on absorption refrigeration according to claim 5, characterized in that: The heat exchange tubes of the low-pressure evaporation chamber (181) and the low-pressure absorption chamber (182) are separated by a first liquid baffle plate (184); The heat exchange tubes of the medium-pressure evaporation chamber (191) and the medium-pressure absorption chamber (192) are separated by a second liquid baffle plate (194).

7. The mixture step-by-step cooling and separation system based on absorption refrigeration according to claim 5, characterized in that: Two baffle plates (199) are provided in the medium-pressure evaporation chamber (191) to separate the heat exchange tube inlet and outlet of the medium-pressure evaporation chamber (191) into three mutually isolated inlets and outlets.

8. The mixture step-by-step cooling and separation system based on absorption refrigeration according to claim 5, characterized in that: A baffle (176) is provided in the shell of the cooling cavity (172).

9. A mixture step-by-step cooling separation process based on absorption refrigeration, using a mixture step-by-step cooling separation system based on absorption refrigeration as claimed in claim 3, characterized in that: The following steps are involved: The gaseous mixture to be separated is introduced into the generator (1) as a heat source to heat the high-pressure rich liquid in the generator (1) to produce a high-pressure gaseous refrigerant, and the gaseous mixture itself is cooled to form a first gas-liquid mixture; The high-pressure gaseous refrigerant enters the condenser (2), is condensed into high-pressure liquid refrigerant by circulating water, and then is divided into two paths. One path is decompressed by a low-pressure expansion valve (6) and enters a low-pressure evaporator (3), and the other path is decompressed by a medium-pressure expansion valve (7) and enters a medium-pressure evaporator (4). The first-stage cyclone separator (8) separates the first gas-liquid mixture, and the liquid produced by the separation enters the medium-pressure evaporator (4) to be cooled and then discharged, and the remaining gas enters the cooler (9) to be cooled by circulating water to form a second gas-liquid mixture; The second gas-liquid mixture enters the secondary cyclone separator (10) for separation, the liquid produced by the separation enters the medium-pressure evaporator (4) to be cooled and then discharged, and the remaining gas enters the low-pressure evaporator (3) to be cooled to form a third gas-liquid mixture; The third gas-liquid mixture enters the third-stage cyclone separator (5) for separation, and the liquid produced by the separation enters the medium-pressure evaporator (4) to be cooled and then discharged, and the remaining gas is directly discharged.

10. A mixture step-by-step cooling separation process based on absorption refrigeration, using a mixture step-by-step cooling separation system based on absorption refrigeration as claimed in any one of claims 5 to 8, characterized in that: The following steps are involved: The gaseous mixture to be separated is introduced into the generating unit (16) as a heat source to heat the high-pressure rich liquid inside the generating unit (16) to produce a high-pressure gaseous refrigerant, and the gaseous mixture itself is cooled to form a first gas-liquid mixture; The high-pressure gaseous refrigerant enters the condensing chamber (171), is condensed into high-pressure liquid refrigerant by circulating water, and then is divided into two paths, one path is decompressed by a low-pressure expansion valve (6) and enters the low-pressure evaporation chamber (181), and the other path is decompressed by a medium-pressure expansion valve (7) and enters the medium-pressure evaporation chamber (191); The first gas-liquid mixture is separated by the first cyclone plate (164), so that the separated liquid enters the medium-pressure evaporation chamber (191) to be cooled and then discharged, and the remaining gas enters the cooling chamber (172) to be cooled by circulating water to form a second gas-liquid mixture; The second gas-liquid mixture is separated by the second cyclone plate (177), the liquid produced by the separation enters the medium-pressure evaporation chamber (191) and is cooled and then discharged, and the remaining gas enters the low-pressure evaporation chamber (181) and is cooled to form a third gas-liquid mixture; The third gas-liquid mixture is separated by the third cyclone plate (188), and the liquid produced by the separation enters the medium-pressure evaporation chamber (191) and is cooled and then discharged, and the remaining gas is directly discharged.

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