A system and method for recovering waste heat from printing and dyeing wastewater

Abstract

The present invention provides a waste heat recovery system and method for printing and dyeing wastewater, including a heat exchanger, a printing and dyeing wastewater collection module, a production water purification supply module and a high-temperature phase change heat storage module. The heat exchanger recovers the heat of the printing and dyeing wastewater and increases the initial water temperature of the purified water entering the printing and dyeing equipment, thereby reducing the amount of heat required to be supplemented at the printing and dyeing equipment and shortening the production waiting time. It can not only save energy and reduce the emission of thermal pollution in the printing and dyeing factory, but also optimize the printing and dyeing production process. The high-temperature phase change heat storage module uses the purified water after the basic water temperature is increased as a water source to provide steam for the printing and dyeing equipment.

Description

Technical Field

[0001] The present invention relates to the field of waste heat recovery, and in particular to a system and method for recovering waste heat from printing and dyeing wastewater. Background Art

[0002] The textile industry is the second largest polluting enterprise after the chemical industry. Every ton of textiles produced will emit 17 tons of greenhouse gases, of which 70% comes from the printing and dyeing process. While printing and dyeing factories have high pollution emissions, a large amount of thermal energy resources are wasted. During the production process of printing and dyeing equipment, a large amount of high-temperature wastewater will be discharged into the sewage system at the equipment outlet, causing serious thermal pollution. A large amount of steam is used in the printing and dyeing process. The high-temperature wastewater generated by the printing and dyeing equipment is recovered for waste heat recovery, which is used for production or to increase the water inlet temperature of the high-temperature phase change thermal storage device. High-quality steam resources can be quickly generated, which can not only save energy and reduce the thermal pollution caused to the environment by the printing and dyeing process, but also can be used in conjunction with the high-temperature phase change thermal storage device to directly use the recovered waste heat for steam supply in the production process after upgrading the temperature grade. Summary of the invention

[0003] In order to solve the problems raised in the background technology, the purpose of the present invention is to provide a printing and dyeing wastewater waste heat recovery system and method, which recovers the heat in the printing and dyeing wastewater, increases the initial water temperature of the production water, or passes the recovered hot water into a high-temperature phase change heat storage device, so as to save energy and reduce pollution.

[0004] To achieve the above-mentioned purpose, the present invention provides a printing and dyeing wastewater waste heat recovery system, comprising a heat exchanger, a printing and dyeing wastewater collection module, a water purification module and a high-temperature phase change heat storage module;

[0005] The printing and dyeing wastewater collection module (2) is connected to the production clean water supply module (3) via the heat exchanger (1); the printing and dyeing wastewater and the production clean water are isolated from each other in the heat exchanger (1); only heat exchange is performed without physical mixing; the high-temperature phase-change heat storage module (4) is connected to the production clean water supply module (3) and uses the high-temperature clean water generated by the production clean water supply module (3) to generate steam.

[0006] Furthermore, the printing and dyeing wastewater collection module (2) comprises: a collection pipe (21) connected to the discharge port of the printing and dyeing equipment; a delivery pipe (24) connecting the heat exchanger and the collection pipe (21); a wastewater pump (25) provided on the delivery pipe (24); and a wastewater discharge pipe (26) connecting the heat exchanger (1) and the wastewater discharge system of the printing and dyeing factory.

[0007] Furthermore, the printing and dyeing wastewater waste heat recovery system also comprises a filtering device (22) and a wastewater buffer pool (23); the filtering device is arranged between the collecting pipe (21) and the wastewater buffer pool (23); and a wastewater pump (25) is arranged on the delivery pipe (24).

[0008] Furthermore, the production clean water supply module comprises: a clean water tank (31) and a clean water circulation pipeline (32); the clean water circulation pipeline (32) connects the clean water tank (31) with the heat exchanger (1); a clean water circulation pump (33) is provided on the clean water circulation pipeline (32); a water replenishment pipe (34) is provided on the upper part of the clean water (31), and a water supply pipe (35) is provided on the lower part.

[0009] Furthermore, the clean water tank (31) is connected to a high-temperature phase-change heat storage module (4), and the high-temperature phase-change heat storage module (4) comprises: an electric heat conversion device, a high-temperature phase-change energy storage material, and a heat exchange device.

[0010] Furthermore, the high-temperature phase-change thermal storage module (4) generates steam using the high-temperature clean water in the clean water tank (31), and the steam is directly used for production or to increase the temperature of the clean water in the clean water tank (31).

[0011] The present invention also provides a method for recovering waste heat from printing and dyeing wastewater. The waste heat recovery system for printing and dyeing wastewater comprises the following steps: S1: Collect high-temperature printing and dyeing wastewater generated by printing and dyeing equipment; S2: Transfer the heat from high-temperature printing and dyeing wastewater to clean water; S3: The heated clean water is supplied to production for use or to a high-temperature phase-change thermal storage module to generate steam for use in production.

[0012] A waste heat recovery system for printing and dyeing wastewater is set up at the end of the printing and dyeing equipment to recover the heat from the high-temperature wastewater generated by the printing and dyeing equipment to produce hot water. When the initial water temperature of the purified water entering the printing and dyeing equipment is increased, under a specific temperature process, the amount of heat required to be supplemented at the printing and dyeing equipment is reduced, and the production waiting time is shortened, which can not only save energy and reduce the emission of thermal pollution from the printing and dyeing factory, but also optimize the printing and dyeing production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A schematic structural diagram of the printing and dyeing wastewater waste heat recovery system of the present invention. DETAILED DESCRIPTION

[0014] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, a detailed description is given below in conjunction with specific implementation cases.

[0015] Figure 1 The structure of the waste heat recovery system for printing and dyeing wastewater of the present invention is shown in FIG. Figure 1 As shown, the waste heat recovery system for printing and dyeing wastewater includes a heat exchanger 1, a printing and dyeing wastewater collection module 2, a production clean water supply module 3 and a high-temperature phase change heat storage module 4. The heat exchanger 1 is used for heat exchange between printing and dyeing wastewater and production clean water; the printing and dyeing wastewater collection module 2 is used to collect and filter the high-temperature printing and dyeing wastewater generated on the printing and dyeing equipment, and transport it to the heat exchanger 1 for heat exchange; the production clean water supply module 3 is used to cache the production clean water, transport the production clean water to the heat exchanger 1 for heat exchange with the printing and dyeing wastewater, and after obtaining the heat of the printing and dyeing wastewater, supply it to the printing and dyeing equipment for production use; the high-temperature phase change heat storage module is used to convert electrical energy into thermal energy for storage, and output energy to the outside in the form of steam.

[0016] The heat exchanger 1 has a primary side and a secondary side, and the primary side and the secondary side have a water inlet port and a water outlet port respectively; the primary side of the heat exchanger 1 is connected to the printing and dyeing wastewater collection module 2, and the secondary side is connected to the production clean water supply module 3. The printing and dyeing wastewater and the production clean water are isolated from each other in the heat exchanger 1, and only heat exchange is performed without physical mixing. After the printing and dyeing wastewater is reduced to a certain temperature through the heat exchanger 1, it directly enters the sewage system; after the production clean water is continuously circulated and heated, it is supplied to the printing and dyeing equipment when the printing and dyeing equipment has water demand; the high-temperature phase change heat storage module uses the heated production clean water as a water source to generate steam, which can increase the steam generation of the high-temperature phase change heat storage module and improve the supply capacity of the high-temperature phase change heat storage module.

[0017] The printing and dyeing wastewater collection module 2 mainly includes a collection pipe 21 connected to the sewage outlet of the printing and dyeing equipment for collecting printing and dyeing wastewater; a filtering device 22 for filtering impurities such as hair in the printing and dyeing wastewater, one end of the filtering device 22 is connected to the collection pipe 21, and the other end is connected to a sewage buffer pool 23 for buffering the printing and dyeing wastewater; a delivery pipe 24 for connecting the printing and dyeing wastewater buffer pool 23 and the primary side water inlet port of the heat exchanger 1; a sewage pump 25 for providing power for the transportation of printing and dyeing wastewater and arranged on the delivery pipe 24; and a sewage pipe 26 for connecting the primary side water outlet port of the heat exchanger 1 and the sewage system of the printing and dyeing factory.

[0018] The production clean water supply module 3 mainly includes a clean water tank 31 for storing clean water; a clean water circulation pipeline 32 for connecting the clean water tank 31 with the water inlet and outlet ends of the secondary side of the heat exchanger 1; a clean water circulation pump 33 for providing power for the clean water circulation and arranged on the clean water circulation pipeline 32; a water replenishment pipe 34 for replenishing water for the clean water tank 31 and arranged on the upper part of the clean water tank; and a water supply pipe 35 for supplying the clean water in the clean water tank 31 to the printing and dyeing equipment and arranged at the lower part of the clean water tank 31.

[0019] The high-temperature phase-change thermal storage module 4 mainly includes an electric-thermal conversion device for converting electrical energy into thermal energy; a high-temperature phase-change energy storage material for storing thermal energy; and a heat exchange device for outputting thermal energy in the form of steam. The water inlet pipe 42 of the high-temperature phase-change thermal storage module 4 is connected to the bottom of the clean water tank 31. The water in the clean water tank is pumped into the phase-change thermal storage device 41 through the water inlet pump 43. After absorbing heat, the water turns into steam, which is supplied to the printing and dyeing equipment for use or to increase the temperature of the clean water through the steam output pipe 44.

[0020] In addition, in order to reduce the heat loss of printing and dyeing sewage and clean water during the heat exchange process, thermal insulation materials are arranged on the surface of the heat exchanger 1, the clean water tank 31, the clean water circulation pipeline 32 and the water supply pipe 35. No driving device is arranged on the collection pipe 21 in the printing and dyeing sewage collection module, and the sewage buffer pool 23 is arranged below the horizontal plane. When the printing and dyeing sewage is discharged, it uses the horizontal height of the printing and dyeing equipment to flow to the sewage buffer pool 23 through the sloped collection pipe 21. During the flow, the printing and dyeing sewage is filtered through the filtering device 22.

[0021] The working process of the above-mentioned printing and dyeing wastewater waste heat recovery system is as follows: the clean water tank 31 is pre-filled with clean water at a certain liquid level through the water supply pipe 34 arranged above it; when the printing and dyeing equipment is started, the printing and dyeing wastewater is generated at any time during the working process of the printing and dyeing equipment, the clean water circulation pump 33 is started, and the clean water begins to circulate between the clean water tank 31, the clean water circulation pipeline 32 and the heat exchanger 1. The high-temperature phase change thermal storage module 4 converts valley electricity or green electricity (wind power, photovoltaic power, etc.) into thermal energy through the electric heat conversion device, and the high-temperature phase change thermal storage material stores the thermal energy.

[0022] After the sewage is discharged from the sewage outlet of the printing and dyeing equipment to the collection pipe 21, it flows into the sewage buffer tank 23 by gravity; the sewage pump 25 transports the sewage in the sewage buffer tank to the heat exchanger 1 through the delivery pipe 24 for heat exchange with the clean water, transfers the heat to the clean water, and after cooling to the designed temperature, it is discharged to the sewage system of the printing and dyeing factory through the sewage pipe 26.

[0023] The heated purified water can be supplied to the printing and dyeing equipment through the water supply pipe 35 at the bottom of the water purification tank, and hot water can be directly provided when the printing and dyeing equipment needs hot water; it can also be supplied to the high-temperature phase-change thermal storage module 4 through the water inlet pipe 42 of the high-temperature phase-change thermal storage module 4, and finally, it can be supplied to the printing and dyeing equipment for use or to increase the temperature of the purified water through the steam output pipe 44. The high-temperature phase-change thermal storage module 4 converts hot water with a certain initial temperature into steam, which can increase the steam generation of the high-temperature phase-change thermal storage module 4 and improve the energy storage efficiency of the high-temperature phase-change thermal storage module 4.

[0024] The steam generated by the high-temperature phase change heat storage module can be directly supplied to the printing and dyeing equipment for production use; it can also be supplied to the clean water tank 31 to further increase the water temperature in the production clean water supply module, thereby ensuring that the production clean water supply module can continue to provide clean water that meets the temperature requirements.

[0025] After using the hot water generated by the waste heat recovery system for printing and dyeing wastewater of the present invention, the initial water temperature of the clean water entering the printing and dyeing equipment is improved. Under a specific temperature process, the amount of heat required to be supplemented is reduced, and the waiting time for production is shortened. While saving energy, the printing and dyeing production process can also be optimized. Moreover, combining waste heat recovery with phase change heat storage can further improve the production efficiency of the phase change heat storage system, and convert more heat into high-temperature steam energy for production use.

[0026] The present invention also provides a method for recovering waste heat from printing and dyeing wastewater, which uses the waste heat recovery system for printing and dyeing wastewater of the present invention, comprising the following steps: S1: Use the printing and dyeing wastewater collection module to collect the high-temperature printing and dyeing wastewater generated by the printing and dyeing equipment; S2: using a heat exchanger to transfer the heat in the high-temperature printing and dyeing wastewater collected by the printing and dyeing wastewater collection module to the purified water; S3: The heated purified water is supplied to production for use or supplied to a high-temperature phase-change thermal storage module to generate steam for use in production.

[0027] It is understood that the present invention is described by some embodiments, and those skilled in the art know that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the scope protected by the present invention.

Claims

1. A printing and dyeing wastewater waste heat recovery system, characterized by: The invention comprises a heat exchanger (1), a printing and dyeing wastewater collection module (2), a production clean water supply module (3), and a high-temperature phase-change heat storage module (4); the printing and dyeing wastewater collection module (2) and the production clean water supply module (3) are connected via the heat exchanger (1); the printing and dyeing wastewater and the production clean water are isolated from each other in the heat exchanger (1); only heat exchange is performed without physical mixing; the high-temperature phase-change heat storage module (4) is connected to the production clean water supply module (3) and uses the high-temperature clean water generated by the production clean water supply module (3) to generate steam.

2. The printing and dyeing wastewater waste heat recovery system according to claim 1, characterized in that: The printing and dyeing wastewater collection module (2) comprises: a collection pipe (21) connected to a discharge port of the printing and dyeing equipment; a delivery pipe (24) connecting the heat exchanger and the collection pipe (21); a wastewater pump (25) provided on the delivery pipe (24); and a wastewater discharge pipe (26) connecting the heat exchanger (1) and a wastewater discharge system of the printing and dyeing factory.

3. The printing and dyeing wastewater waste heat recovery system according to claim 2, characterized in that: The printing and dyeing wastewater waste heat recovery system further comprises a filtering device (22) and a wastewater buffer pool (23); the filtering device is arranged between the collecting pipe (21) and the wastewater buffer pool (23); and a wastewater pump (25) is arranged on the delivery pipe (24).

4. The printing and dyeing wastewater waste heat recovery system according to claim 1, characterized in that: The production clean water supply module comprises: a clean water tank (31) and a clean water circulation pipeline (32); the clean water circulation pipeline (32) connects the clean water tank (31) and the heat exchanger (1); a clean water circulation pump (33) is arranged on the clean water circulation pipeline (32); a water replenishment pipe (34) is arranged on the upper part of the clean water (31), and a water supply pipe (35) is arranged on the lower part.

5. The printing and dyeing wastewater waste heat recovery system according to claim 4, characterized in that: The clean water tank (31) is connected to a high-temperature phase-change heat storage module (4), wherein the high-temperature phase-change heat storage module (4) comprises an electric-thermal conversion device, a high-temperature phase-change energy storage material, and a heat exchange device.

6. The printing and dyeing wastewater waste heat recovery system according to claim 5, characterized in that: The high-temperature phase-change heat storage module (4) utilizes the high-temperature clean water in the clean water tank (31) to generate steam, and the steam is directly used for production or to increase the temperature of the clean water in the clean water tank (31).

7. A method for recovering waste heat from printing and dyeing wastewater, using the waste heat recovery system for printing and dyeing wastewater as claimed in any one of claims 1 to 6, characterized in that: The steps are as follows: S1: Collect high-temperature printing and dyeing wastewater generated by printing and dyeing equipment; S2: Transfer the heat from high-temperature printing and dyeing wastewater to clean water; S3: The heated clean water is supplied to production for use or to a high-temperature phase-change thermal storage module to generate steam for use in production.

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