Acetic acid steam condensation waste heat recovery system

Abstract

The acetic acid steam condensation waste heat recovery system comprises a first-section waste heat exchanger, a water pump, a working medium evaporator, an expansion generator, a working medium condenser, a working medium pump, a second-section waste heat exchanger, a lithium bromide refrigerating unit and a third-section condenser. Desalted water is used for absorbing condensation heat of acetic acid steam, and then organic Rankine cycle is adopted for recycling heat of the desalted water for power generation. Meanwhile, the heat of desalted water is recovered by adopting a lithium bromide heat absorption evaporation refrigeration principle to refrigerate and prepare chilled water, so that the condensation heat of acetic acid steam is efficiently recycled.

Description

Technical Field

[0001] The present application belongs to the field of new energy technology, and in particular, relates to an acetic acid steam condensation waste heat recovery system. Background Art

[0002] Acetic acid (acetic acid, CH3COOH) is an important organic acid, widely used in chemical, food, medicine and other fields. The production process of acetic acid mainly includes oxidation, absorption, condensation and distillation. In the condensation stage, the acetic acid vapor is cooled into liquid through the condenser, which releases a lot of heat energy. If this heat energy cannot be effectively recovered, it will not only cause energy waste, but also increase the burden and operating cost of the cooling system. Utility Model Content

[0003] The technical problem to be solved by the utility model is: to solve the deficiency that heat energy cannot be effectively recovered in the prior art, thereby providing an acetic acid steam condensation waste heat recovery system.

[0004] The technical solution adopted by the utility model to solve its technical problems is:

[0005] An acetic acid steam condensation waste heat recovery system comprises a first-stage reaction device, a second-stage reaction device, and a third-stage reaction device which are sequentially connected through pipelines. The first-stage reaction device, the second-stage reaction device, and the third-stage reaction device cooperate with each other to complete an organic Rankine cycle to recover desalted water. The acetic acid steam pipeline introduces acetic acid steam into the first-stage reaction device. The first-stage reaction device comprises a first-stage waste heat exchanger, a working fluid evaporator, an expansion generator, a working fluid condenser, and a working fluid pump. The first-stage waste heat exchanger and the working fluid evaporator are connected through pipelines. The first desalted water in the tube side of the first-stage waste heat exchanger absorbs the heat of the acetic acid steam and then heats up. The acetic acid steam in the shell side releases the heat and becomes an acetic acid gas-liquid mixture. The first desalted water after absorbing heat is transported by a water pump into the tube side of the working fluid evaporator.

[0006] The working fluid evaporator and the working fluid condenser are connected through pipelines. The expansion generator is set on the pipeline from the working fluid evaporator input medium to the working fluid condenser, and the working fluid pump is set on the pipeline from the working fluid condenser output medium to the working fluid evaporator. The working fluid in the shell side of the working fluid evaporator absorbs heat and evaporates into high-pressure gaseous working fluid, enters the expansion chamber of the expansion generator to work and drive the generator to operate, and outputs electricity to the outside. The expanded low-pressure gaseous working fluid enters the shell side of the working fluid condenser, and is converted into low-pressure liquid working fluid after being absorbed by the circulating cooling water in the tube side. The low-pressure liquid working fluid is transported to the shell side of the working fluid evaporator by the working fluid pump to evaporate, thereby completing an organic Rankine cycle.

[0007] Furthermore, the first stage waste heat exchanger is a shell and tube heat exchanger, the tube side medium is desalted water, and the shell side medium is acetic acid steam.

[0008] Furthermore, the expansion generator is a generator structure driven by a centrifugal or screw expander.

[0009] Furthermore, the working medium evaporator is a shell and tube heat exchanger, the tube side medium is desalted water, and the shell side medium is liquid working medium.

[0010] Furthermore, the working fluid condenser is a shell and tube heat exchanger, the tube side medium is circulating cooling water, and the shell side medium is gaseous working fluid.

[0011] Furthermore, the second-stage reaction equipment includes a second-stage waste heat exchanger and a lithium bromide refrigeration unit connected by pipelines, and a water pump is arranged on the pipelines. The lithium bromide refrigeration unit absorbs the heat of the desalted water to produce low-temperature chilled water. The acetic acid gas-liquid mixture enters the shell side of the second-stage waste heat exchanger, and is converted into a gas-liquid mixture containing a small amount of acetic acid vapor after absorbing the heat by the second desalted water in the tube side. The heated second desalted water is transported by the water pump into the lithium bromide refrigeration unit to release heat, and the lithium bromide refrigeration unit produces low-temperature chilled water for output.

[0012] Furthermore, the second-stage waste heat exchanger is a shell and tube heat exchanger structure, the tube-side medium is circulating cooling water, and the shell-side medium is acetic acid gas-liquid mixture.

[0013] Furthermore, the three-stage reaction equipment includes three-stage condensers.

[0014] Furthermore, the three-stage condenser is a shell and tube heat exchanger, the tube side medium is desalted water, the shell side medium is acetic acid gas-liquid mixture, the gas-liquid mixture containing a small amount of acetic acid vapor enters the shell side of the three-stage condenser, and is condensed into liquid acetic acid by the circulating cooling water in the tube side and output

[0015] The beneficial effects of the utility model are:

[0016] Desalted water is used to absorb the condensation heat of acetic acid vapor, and then the organic Rankine cycle is used to recover the heat of desalted water for power generation. At the same time, the heat of desalted water is recovered by the lithium bromide endothermic evaporation refrigeration principle for refrigeration and production of chilled water. Thus, the efficient recovery and utilization of the condensation heat of acetic acid vapor is achieved. It has the advantages of simple system, high comprehensive utilization efficiency of waste heat, and good economic benefits. It can effectively solve the energy waste problem of condensation heat of acetic acid vapor. Therefore, it has great significance for promoting the economic improvement of the operation of acetic acid production equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The technical solution of the present application is further described below in conjunction with the accompanying drawings and embodiments.

[0018] Figure 1 It is a schematic diagram of the structure of an embodiment of the present application;

[0019] The reference numerals in the figure are:

[0020] 01. One-stage waste heat exchanger; 02. Water pump; 03. Working fluid evaporator; 04. Expansion generator; 05. Working fluid condenser; 06. Working fluid pump; 07. Two-stage waste heat exchanger; 08. Lithium bromide refrigeration unit; 09. Three-stage condenser; 10. Acetic acid steam circuit; 11. First desalted water circuit; 12. R245FA working fluid circuit; 13. Second desalted water circuit; 14. Circulating cooling water circuit; 15. Low-temperature freezing water circuit; 16. Liquid acetic acid circuit. DETAILED DESCRIPTION

[0021] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0022] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the invention of the present utility model, unless otherwise specified, "multiple" means two or more.

[0023] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood by specific circumstances.

[0024] The technical solution of the present application will be described in detail below with reference to the accompanying drawings and in combination with embodiments. Example

[0025] The present embodiment provides an acetic acid steam condensation waste heat recovery system, comprising a first-stage waste heat exchanger 01, a water pump 02, a working fluid evaporator 03, an expansion generator 04, a working fluid condenser 05, a working fluid pump 06, a second-stage waste heat exchanger 07, a lithium bromide refrigeration unit 08 and a third-stage condenser 09. The first-stage reaction equipment, the second-stage reaction equipment and the third-stage reaction equipment cooperate with each other to complete the organic Rankine cycle to recover desalted water.

[0026] The first stage waste heat exchanger 01 is a shell and tube heat exchanger structure, the tube side medium is desalted water, and the shell side medium is acetic acid steam.

[0027] The working fluid evaporator 03 is a shell and tube heat exchanger, the tube side medium is desalted water, and the shell side medium is liquid R245FA working fluid.

[0028] The expansion generator 04 is a generator structure driven by a centrifugal or screw expander.

[0029] The working medium condenser 05 is a shell and tube heat exchanger, the tube side medium is circulating cooling water, and the shell side medium is gaseous R245FA working medium.

[0030] The second-stage waste heat exchanger 07 is a shell and tube heat exchanger structure, the tube side medium is circulating cooling water, and the shell side medium is acetic acid gas-liquid mixture.

[0031] Lithium bromide refrigeration unit 08 is a two-stage lithium bromide absorption chiller that produces process chilled water by absorbing heat.

[0032] The three-stage condenser 09 is a shell and tube heat exchanger structure, the tube side medium is desalted water, and the shell side medium is acetic acid gas-liquid mixture.

[0033] The acetic acid steam circuit 10 connects the shell side of the first stage waste heat exchanger 01, the shell side of the second stage waste heat exchanger 07 and the shell side of the third stage condenser 09 together.

[0034] The first desalted water pipeline 11 connects a tube side of the waste heat exchanger 01 and a tube side of the working medium evaporator 03 together.

[0035] The R245FA working fluid circuit 12 connects the shell side of the working fluid evaporator 03 , the expansion generator 04 , the shell side of the working fluid condenser 05 and the working fluid pump 06 together.

[0036] The second desalted water pipeline 13 connects the tube side of the second-stage waste heat exchanger 07 and the lithium bromide refrigeration unit 08 together.

[0037] In a feasible implementation scheme of the present invention, acetic acid vapor at 125°C enters the shell side of a waste heat exchanger 01, and the first desalted water in the tube side absorbs the heat of the acetic acid vapor and heats up to 120°C. The acetic acid vapor in the shell side releases heat and becomes an acetic acid gas-liquid mixture at 100°C; the first desalted water at 120°C after absorbing heat is transported by a water pump 02 into the tube side of the working fluid evaporator 03, and the R245FA working fluid in the shell side absorbs heat and evaporates into a high-pressure gaseous working fluid, and enters the expansion chamber of the expansion generator 04 to work and drive the generator to operate, and output electricity to the outside, and the first desalted water after releasing heat is cooled to 95°C and enters the waste heat exchanger 01 again to absorb heat; then the expanded low-pressure gaseous R245FA working fluid enters the shell side of the working fluid condenser 05, and is converted into a low-pressure liquid R245FA working fluid after being absorbed by the circulating cooling water in the tube side. The low-pressure liquid R245FA working fluid is transported by the working fluid pump 06 to the shell side of the working fluid evaporator 03 for evaporation, thereby completing an organic Rankine cycle.

[0038] The 100°C acetic acid gas-liquid mixture enters the shell side of the second-stage waste heat exchanger 07, and is converted into a 65°C gas-liquid mixture containing a small amount of acetic acid vapor after being absorbed by the second desalted water in the tube side. The second desalted water at 95°C after being heated is transported by the water pump 02 into the lithium bromide refrigeration unit 08 to release heat. The lithium bromide refrigeration unit 08 produces 5°C chilled water for output. The second desalted water is cooled to 60°C and enters the second-stage waste heat exchanger 07 again to absorb heat. The gas-liquid mixture containing a small amount of acetic acid vapor enters the shell side of the third-stage condenser 09, and is condensed into 30°C liquid acetic acid by the circulating cooling water in the tube side and output through the liquid acetic acid line 16.

[0039] Based on the above ideal embodiments of this application, the relevant staff can make various changes and modifications without departing from the technical concept of this application through the above description. The technical scope of this application is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An acetic acid steam condensation waste heat recovery system, characterized in that: It comprises a first-stage reaction device, a second-stage reaction device and a third-stage reaction device which are sequentially connected through pipelines. The first-stage reaction device, the second-stage reaction device and the third-stage reaction device cooperate with each other to complete the organic Rankine cycle to recover desalted water. The first-stage reaction device comprises a waste heat exchanger, a working fluid evaporator, an expansion generator, a working fluid condenser and a working fluid pump; the first-stage waste heat exchanger and the working fluid evaporator are connected through pipelines, the working fluid evaporator and the working fluid condenser are connected through pipelines, the expansion generator is arranged on the working fluid conveying pipeline between the working fluid evaporator and the working fluid condenser, and the working fluid pump is arranged on the pipeline for the working fluid condenser to output the medium to the working fluid evaporator.

2. The acetic acid steam condensation waste heat recovery system according to claim 1, characterized in that: The first stage waste heat exchanger is a shell and tube heat exchanger, the tube side medium is desalted water, and the shell side medium is acetic acid steam.

3. The acetic acid steam condensation waste heat recovery system according to claim 1, characterized in that: The expansion generator is a generator structure driven by a centrifugal or screw expander.

4. The acetic acid steam condensation waste heat recovery system according to claim 1, characterized in that: The working medium evaporator is a shell and tube heat exchanger, the tube side medium is desalted water, and the shell side medium is liquid working medium.

5. The acetic acid steam condensation waste heat recovery system according to claim 1, characterized in that: The working medium condenser is a shell and tube heat exchanger, the tube side medium is circulating cooling water, and the shell side medium is gaseous working medium.

6. The acetic acid steam condensation waste heat recovery system according to claim 1, characterized in that: The two-stage reaction equipment comprises two-stage waste heat exchangers and a lithium bromide refrigeration unit which are connected through pipelines.

7. The acetic acid steam condensation waste heat recovery system according to claim 6, characterized in that: The two-stage waste heat exchanger is a shell and tube heat exchanger structure, the tube side medium is circulating cooling water, and the shell side medium is acetic acid gas-liquid mixture.

8. The acetic acid steam condensation waste heat recovery system according to claim 1, characterized in that: The three-stage reaction equipment comprises three-stage condensers.

9. The acetic acid steam condensation waste heat recovery system according to claim 8, characterized in that: The three-stage condenser is a shell and tube heat exchanger, the tube side medium is desalted water, and the shell side medium is an acetic acid gas-liquid mixture.

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