Waste gas heat recovery treatment system

Abstract

The utility model discloses a waste gas heat recovery treatment system. The system comprises an absorption tower, a chimney, a water circulation device and a heat exchanger. The absorption tower is provided with a waste gas output pipeline; the chimney is provided with a waste gas input pipeline; the water circulation device is provided with a water input pipeline and a water output pipeline; the heat exchanger is provided with an air inlet pipeline, an air outlet pipeline, a water inlet pipeline and a water outlet pipeline; the gas inlet pipeline is connected to a waste gas output pipeline of the absorption tower, the gas outlet pipeline is connected to a waste gas input pipeline of the chimney, the water inlet pipeline is connected to a water output pipeline of the water circulation device, and the water outlet pipeline is connected to a water input pipeline of the water circulation device. The waste gas of the absorption tower is in heat exchange connection with the water circulation device through the heat exchanger, the temperature of the industrial waste gas can be further utilized, resource waste is avoided, and the operation cost is reduced.

Description

Technical Field

[0001] This application relates to the technical field of silicon solar cell manufacturing, and specifically relates to an exhaust gas heat recovery and treatment system. Background Art

[0002] When treating ammonia exhaust gas in the silicon solar cell manufacturing section of the silicon solar industry, the temperature of the exhaust gas needs to be reduced during the process of recovering ammonia water from the ammonia exhaust gas. An ambient temperature of 5 degrees Celsius can improve the absorption effect of ammonia exhaust gas in pure water. At the same time, packing is provided in the absorption tower to effectively increase the contact area between gas and liquid, enabling pure water to capture and dissolve ammonia in the exhaust gas to form ammonia water. During this process, maintaining an ambient temperature of 5 degrees Celsius requires a refrigeration machine to continuously refrigerate and cool the circulating water through a heat exchanger to achieve the purpose of controlling the ambient temperature in the tower. When the ammonia exhaust gas is discharged, it is about 5 - 7 degrees Celsius, and the remaining cold is directly discharged, resulting in a waste of resources and increasing operating costs.

[0003] Similarly, when the temperature of industrial exhaust gas is high, directly discharging the high-temperature gas will also cause waste of resources and increase operating costs. Utility Model Content

[0004] The embodiments of this application provide an exhaust gas heat recovery and treatment system, which can solve the technical problems that the temperature of industrial exhaust gas is not reused, and directly discharging low-temperature or high-temperature gas will also cause waste of resources and increase operating costs.

[0005] The embodiments of this application provide an exhaust gas heat recovery and treatment system, including:

[0006] An absorption tower, provided with an exhaust gas output pipeline;

[0007] A chimney, provided with an exhaust gas input pipeline;

[0008] A water circulation device, provided with a water input pipeline and a water output pipeline;

[0009] A heat exchanger, provided with an intake pipeline, an outlet pipeline, a water inlet pipeline, and a water outlet pipeline; the intake pipeline is connected to the exhaust gas output pipeline of the absorption tower, the outlet pipeline is connected to the exhaust gas input pipeline of the chimney, the water inlet pipeline is connected to the water output pipeline of the water circulation device, and the water outlet pipeline is connected to the water input pipeline of the water circulation device.

[0010] Further, the heat exchanger includes a gas heat exchange layer and water heat exchange tubes. The gas heat exchange layer is connected to the intake pipeline and the outlet pipeline, the water heat exchange tubes are connected to the water inlet pipeline and the water outlet pipeline, and the gas transmission direction in the gas heat exchange layer is opposite to the water flow transmission direction in the water heat exchange tubes.

[0011] Further, the gas heat exchange layer is rectangular, the water heat exchange pipe is wavy, and the water heat exchange pipe is in contact with the gas heat exchange layer.

[0012] Further, a plurality of the gas heat exchange layers and the water heat exchange pipes are provided, and the gas heat exchange layers and the water heat exchange pipes are arranged in an overlapping manner in sequence.

[0013] Further, the water circulation device includes a water storage tank and a circulation pump. The water storage tank is provided with the water input pipe and the water output pipe, and the circulation pump is connected between the water output pipe and the water inlet pipe.

[0014] Further, the water circulation device includes a circulation valve and a temperature sensor; the circulation valve is arranged between the circulation pump and the water inlet pipe; the water storage tank is provided with a water supply pipe, and the temperature sensor is arranged on the water supply pipe. The temperature sensor is electrically connected to the circulation valve and the circulation pump.

[0015] Further, the water circulation device includes a heat exchange device and a water supply pump. The water storage tank is further provided with a return water pipe that is communicated with the water supply pipe and returns to the water storage tank, and the water supply pump and the heat exchange device are arranged on the water supply pipe.

[0016] Further, the water circulation device includes a water replenishing pipe and a water supply valve. The water supply valve is arranged on the water replenishing pipe, and the water replenishing pipe is connected to the water inlet pipe.

[0017] Further, the water circulation device includes a liquid level valve. The liquid level valve is arranged in the water storage tank, and the water supply valve is electrically connected to the liquid level valve.

[0018] Further, the water input pipe is arranged at the top of the water storage tank, and the water output pipe is arranged at the bottom of the water storage tank.

[0019] The waste gas heat recovery and treatment system provided by the embodiment of the present application realizes heat exchange connection between the waste gas of the absorption tower and the water circulation device through a heat exchanger, can further utilize the temperature of industrial waste gas, avoids waste of resources, and reduces operating costs. Description of the Drawings

[0020] The following will make the technical solutions and other beneficial effects of the present application obvious by describing the specific embodiments of the present application in detail in conjunction with the drawings.

[0021] Figure 1 It is a schematic structural diagram of the waste gas heat recovery and treatment system provided by the embodiment of the present application.

[0022] Figure 2 It is a schematic plan view of the heat exchanger provided by the embodiment of the present application.

[0023] The identifications in the figure are as follows:

[0024] Absorption tower 1, exhaust gas output pipeline 11, chimney 2, exhaust gas input pipeline 21, water circulation device 3, water input pipeline 31, water output pipeline 32, water storage tank 33, circulation pump 34, circulation valve 35, temperature sensor 36, heat exchange equipment 37, water supply pump 38, return water pipeline 39, make-up water pipeline 310, water supply valve 311, liquid level valve 312, water supply pipeline 313, heat exchanger 4, intake pipeline 41, outlet pipeline 42, inlet water pipeline 43, outlet water pipeline 44, gas heat exchange layer 45, water heat exchange tube 46. Specific implementation manners

[0025] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts belong to the scope of protection of the present application.

[0026] In the description of the present application, it should be noted that, unless otherwise clearly defined and limited, the terms "installation", "connection", and "connection" 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, an electrical connection, or a communication with each other; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0027] Specifically, please refer to Figure 1 , the embodiments of the present application provide an exhaust gas heat recovery and treatment system, and the exhaust gas heat recovery and treatment system includes an absorption tower 1, a chimney 2, a water circulation device 3, and a heat exchanger 4.

[0028] The absorption tower 1 is provided with an exhaust gas output pipeline 11; the chimney 2 is provided with an exhaust gas input pipeline 21; the water circulation device 3 is provided with a water input pipeline 31 and a water output pipeline 32; the heat exchanger 4 is provided with an intake pipeline 41, an outlet pipeline 42, an inlet water pipeline 43, and an outlet water pipeline 44; the intake pipeline 41 is connected to the exhaust gas output pipeline 11 of the absorption tower 1, the outlet pipeline 42 is connected to the exhaust gas input pipeline 21 of the chimney 2, the inlet water pipeline 43 is connected to the water output pipeline 32 of the water circulation device 3, and the outlet water pipeline 44 is connected to the water input pipeline 31 of the water circulation device 3.

[0029] The waste gas heat recovery treatment system can achieve heat exchange between the waste gas of the absorption tower 1 and the water circulation device 3 through the heat exchanger 4, transfer the heat energy of the waste gas released by the absorption tower 1 to the water circulation device 3 through the heat exchanger 4, and the waste gas after passing through the heat exchanger 4 is discharged through the chimney 2. The water circulation device 3 can realize the cyclic treatment and utilization of the heat-exchanged water.

[0030] When the waste gas output from the absorption tower 1 is at a high temperature, the high-temperature waste gas exchanges heat with the water in the water circulation device 3 through the heat exchanger 4 to heat the water in the water circulation device 3.

[0031] When the waste gas output from the absorption tower 1 is at a low temperature, the low-temperature waste gas exchanges heat with the water in the water circulation device 3 through the heat exchanger 4 to cool the water in the water circulation device 3.

[0032] The waste gas heat recovery treatment system provided by the embodiment of the present application realizes heat exchange connection between the waste gas of the absorption tower 1 and the water circulation device 3 through the heat exchanger 4, can further utilize the temperature of industrial waste gas, avoids waste of resources, and reduces operating costs.

[0033] Please refer to Figure 2 , the heat exchanger 4 includes a gas heat exchange layer 45 and water heat exchange tubes 46. The gas heat exchange layer 45 is connected to the intake pipe 41 and the outlet pipe 42, and the water heat exchange tubes 46 are connected to the inlet pipe 43 and the outlet pipe 44. The gas transmission direction in the gas heat exchange layer 45 is opposite to the water flow transmission direction in the water heat exchange tubes 46. The opposite transmission directions of the gas heat exchange layer 45 and the water heat exchange tubes 46 of the heat exchanger 4 can achieve sufficient heat exchange. For example, when the waste gas output from the waste gas output pipe 11 of the absorption tower 1 is at a high temperature, the temperature of the waste gas output from the outlet pipe 42 is lower than the temperature of the waste gas input from the intake pipe 41, the water temperature in the inlet pipe 43 of the water circulation device 3 is close to the temperature of the waste gas output from the outlet pipe 42, and the water temperature in the outlet pipe 44 of the water circulation device 3 is close to the temperature of the waste gas input from the intake pipe 41. Therefore, heat exchange can be continuously carried out between the outlet pipe 44 and the intake pipe 41, and sufficient heat exchange can be achieved.

[0034] Furthermore, the gas heat exchange layer 45 is rectangular, the water heat exchange tubes 46 are wavy, and the water heat exchange tubes 46 are in contact with the gas heat exchange layer 45. The wavy shape of the water heat exchange tubes 46 can increase the heat exchange contact area and achieve sufficient heat exchange. The contact between the water heat exchange tubes 46 and the gas heat exchange layer 45 can achieve sufficient heat conduction.

[0035] Further, there are multiple gas heat exchange layers 45 and water heat exchange tubes 46, and the gas heat exchange layers 45 and the water heat exchange tubes 46 are arranged in an overlapping manner in sequence. Specifically, both ends of the gas heat exchange layer 45 are connected to the intake pipe 41 and the outlet pipe 42, and gas is contained within the gas heat exchange layer 45. When multiple water heat exchange tubes 46 are provided, the water heat exchange tubes 46 can be arranged in multiple layers, and each layer of the water heat exchange tubes 46 is arranged in a bow shape or an S shape. The gas heat exchange layer 45 is provided with through holes for passing through the water heat exchange tubes 46. Therefore, the gas heat exchange layer 45 is also arranged in multiple layers corresponding to the multiple layers of water heat exchange tubes 46, achieving sufficient contact between the gas heat exchange layer 45 and the water heat exchange tubes 46 and enabling sufficient heat conduction.

[0036] Further, the water circulation device 3 includes a water storage tank 33 and a circulation pump 34. The water storage tank 33 is provided with a water input pipe 31 and a water output pipe 32, and the circulation pump 34 is connected between the water output pipe 32 and the water inlet pipe 43. The water storage tank 33 can store the heat-exchanged water, temporarily store it when the heat-exchanged water is not utilized, and can adjust the water temperature when storing the heat-exchanged water. The circulation pump 34 can promote the water circulation between the water output pipe 32 and the water inlet pipe 43, promote the heat exchange of the water stored in the water storage tank 33, and maintain the water temperature constant.

[0037] Further, the water circulation device 3 includes a circulation valve 35 and a temperature sensor 36; the circulation valve 35 is arranged between the circulation pump 34 and the water inlet pipe 43; the water storage tank 33 is provided with a water supply pipe 313, and the temperature sensor 36 is arranged on the water supply pipe 313. The temperature sensor 36 is electrically connected to the circulation valve 35 and the circulation pump 34. The temperature sensor 36 can monitor the real-time temperature of the water discharged from the water supply pipe 313 of the water storage tank 33 in real time. The circulation pump 34 obtains the real-time temperature monitored by the temperature sensor 36 and adjusts the power of the circulation pump 34 according to the water temperature to control the heat exchange cycle frequency, thereby performing heat exchange on the water stored in the water storage tank 33 and maintaining the water temperature constant.

[0038] Further, the water circulation device 3 includes a heat exchange device 37 and a water supply pump 38. The water storage tank 33 is further provided with a return water pipe 39 that communicates with the water supply pipe 313 and returns to the water storage tank 33, and the water supply pump 38 and the heat exchange device 37 are arranged on the water supply pipe 313. The heat exchange device 37 can exchange heat with the external air and make full use of the heat energy of the water stored in the water storage tank 33. When it is necessary to cool the outside, the temperature of the water stored in the water storage tank 33 is lower than the room temperature, and the heat exchange device 37 can absorb the temperature of the external air and cool the outside. When it is necessary to heat the outside, the temperature of the water stored in the water storage tank 33 is higher than the room temperature, and the heat exchange device 37 can heat the external air.

[0039] Further, the water circulation device 3 includes a makeup water pipe 310 and a water supply valve 311. The water supply valve 311 is arranged on the makeup water pipe 310, and the makeup water pipe 310 is connected to the water inlet pipe 43.

[0040] Further, the water circulation device 3 includes a liquid level valve 312. The liquid level valve 312 is disposed in the water storage tank 33, and the water supply valve 311 is electrically connected to the liquid level valve 312. The liquid level valve 312 can monitor the water level in the water storage tank 33. When the water level in the water storage tank 33 reaches the highest threshold, the liquid level valve 312 feeds back a control signal to the water supply valve 311 to stop the water supply valve 311 from supplying water to the water storage tank 33. When the water level in the water storage tank 33 is lower than the highest threshold, the liquid level valve 312 feeds back a control signal to the water supply valve 311 to control the water supply valve 311 to supply water to the water storage tank 33.

[0041] Further, the water input pipe 31 is disposed at the top of the water storage tank 33, and the water output pipe 32 is disposed at the bottom of the water storage tank 33. The water input pipe 31 at the top of the water storage tank 33 intakes water, and the water output pipe 32 at the bottom of the water storage tank 33 discharges water. In this way, the water pressure can be utilized to facilitate the discharge of the water in the water storage tank 33 from the water output pipe 32.

[0042] It can be understood that this application can be used to utilize the high temperature or low temperature of the waste gas to exchange heat with the water in the water circulation device 3 through the heat exchanger 4 to achieve heat reuse.

[0043] When the waste gas output from the waste gas output pipe 11 of the absorption tower 1 is at a high temperature, for example, the waste gas temperature is greater than 25 °C, the high-temperature waste gas enters the gas heat exchange layer 45 of the heat exchanger 4, and the high-temperature waste gas exchanges heat with the water in the water heat exchange pipe 46 to heat the water in the water circulation device 3 connected to the water heat exchange pipe 46.

[0044] When the waste gas output from the waste gas output pipe 11 of the absorption tower 1 is at a low temperature, for example, the waste gas temperature is less than 15 °C, the low-temperature waste gas enters the gas heat exchange layer 45 of the heat exchanger 4, and the low-temperature waste gas exchanges heat with the water in the water heat exchange pipe 46 to cool the water in the water circulation device 3 connected to the water heat exchange pipe 46.

[0045] The following is an example. In order to reduce problems such as resource waste generated by the existing waste gas treatment system for silicon solar production, achieve resource recycling, and reduce the production cost of products, this application is applied to the ammonia waste gas recovery and treatment system in the silicon solar industry, and the cold energy in the waste gas is recovered through heat exchange. After recovery, the low-temperature pure water enters the water storage tank 33 (pure water tank).

[0046] (1) Install a heat exchanger 4 in the pipeline from the 4-stage absorption tower to the chimney section. The heat exchanger 4 adopts the form of stainless steel corrugated fin tubes and bellows tubes to increase the heat exchange area and turbulence degree on the air side, and the effects of the two forms of heat exchangers will be compared.

[0047] The heat exchanger 4 is of the gas-water heat exchange type. The inlet and outlet temperatures of the gas phase are 5°C / 15°C, and the inlet and outlet temperatures of the liquid phase are 20°C / 15°C. The heat transfer capacity is 50 kW. The water flow direction is opposite to the gas flow direction.

[0048] (2) The makeup water system transports pure water to first enter the heat exchanger 4 to recover the residual cold, pre-cools the water temperature, and then replenishes it into the water storage tank 33. The liquid level of the water storage tank 33 controls the opening and closing of the water supply valve 311. When the liquid level is high, the makeup water is closed, and when the liquid level is low, the makeup water is opened.

[0049] The pre-cooled pure water is mixed with the pure water returning to the water storage tank 33. The recycling pump 34 is turned on to keep the water in the tank enter the heat exchanger 4 to recover the residual cold in the tail gas. When the outlet temperature of the tank is less than or equal to 5°C, the recycling pump 34 and the recycling valve 35 are closed. When it is greater than 5°C, the recycling pump 34 and the recycling valve 35 are turned on to recover the low-temperature cold energy in the tail gas.

[0050] In the above embodiment, the ammonia waste gas absorption medium is pre-cooled by installing the heat exchanger 4 at the pipeline (chimney). The pre-cooled absorption medium is sent to the water storage tank 33 to be mixed with the system circulating return water, and then sent to the heat exchanger 4 for temperature reduction.

[0051] The waste gas heat recovery treatment system provided by the embodiment of the present application realizes the heat exchange connection between the waste gas of the absorption tower 1 and the water circulation device 3 through the heat exchanger 4, can further utilize the temperature of the industrial waste gas, avoids waste of resources, and reduces the operation cost.

[0052] In the above embodiments, the descriptions of each embodiment have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0053] The above has introduced in detail a waste gas heat recovery treatment system provided by the embodiment of the present application. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the technical solution and its core idea of the present application; those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A waste gas heat recovery treatment system, characterized in that: include: An absorption tower is provided with an exhaust gas output pipeline; A chimney with an exhaust gas input duct; A water circulation device, provided with a water input pipe and a water output pipe; The heat exchanger is provided with an air inlet pipe, an air outlet pipe, a water inlet pipe and a water outlet pipe; the air inlet pipe is connected to the exhaust gas output pipe of the absorption tower, the air outlet pipe is connected to the exhaust gas input pipe of the chimney, the water inlet pipe is connected to the water output pipe of the water circulation device, and the water outlet pipe is connected to the water input pipe of the water circulation device.

2. The exhaust gas heat recovery treatment system according to claim 1, characterized in that: The heat exchanger includes a gas heat exchange layer and a water heat exchange tube. The gas heat exchange layer is connected to the air inlet pipe and the air outlet pipe. The water heat exchange tube is connected to the water inlet pipe and the water outlet pipe. The gas transmission direction in the gas heat exchange layer is opposite to the water flow transmission direction in the water heat exchange tube.

3. The exhaust gas heat recovery treatment system according to claim 2, characterized in that: The gas heat exchange layer is rectangular, the water heat exchange tube is wavy, and the water heat exchange tube abuts against the gas heat exchange layer.

4. The exhaust gas heat recovery treatment system according to claim 2, characterized in that: The gas heat exchange layer and the water heat exchange tube are both provided in plurality, and the gas heat exchange layer and the water heat exchange tube are arranged overlappingly in sequence.

5. The exhaust gas heat recovery treatment system according to claim 1, characterized in that: The water circulation device comprises a water storage tank and a circulation pump. The water storage tank is provided with the water input pipe and the water output pipe. The circulation pump is connected between the water output pipe and the water inlet pipe.

6. The exhaust gas heat recovery treatment system according to claim 5, characterized in that: The water circulation device includes a circulation valve and a temperature sensor; the circulation valve is arranged between the circulation pump and the water inlet pipe; the water storage tank is provided with a water supply pipe, the water supply pipe is provided with the temperature sensor, and the temperature sensor is electrically connected to the circulation valve and the circulation pump.

7. The exhaust gas heat recovery treatment system according to claim 6, characterized in that: The water circulation device includes a heat exchange device and a water supply pump. The water storage tank is also provided with a return pipe which is connected with the water supply pipe and flows back to the water storage tank. The water supply pump and the heat exchange device are arranged on the water supply pipe.

8. The exhaust gas heat recovery treatment system according to claim 5, characterized in that: The water circulation device comprises a water replenishment pipeline and a water supply valve. The water supply valve is arranged on the water replenishment pipeline, and the water replenishment pipeline is connected to the water inlet pipeline.

9. The exhaust gas heat recovery treatment system according to claim 8, characterized in that: The water circulation device comprises a liquid level valve, which is arranged in the water storage tank, and the water supply valve is electrically connected to the liquid level valve.

10. The exhaust gas heat recovery treatment system according to claim 5, characterized in that: The water input pipe is arranged at the top of the water storage tank, and the water output pipe is arranged at the bottom of the water storage tank.

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