Waste heat recovery system for chlorine-containing flue gas

Abstract

The utility model discloses a waste heat recovery system for chlorine-containing flue gas, which belongs to the technical field of chemical equipment and comprises a steam cooling device and a waste heat recoverer. The steam cooling device comprises a steam pocket and a steam adjusting assembly; the steam adjusting assembly is connected with the steam pocket and used for adjusting the temperature of cooling water in the steam pocket by adjusting the steam pressure in the steam pocket. The waste heat recoverer comprises a heat exchanger and a central breather pipe; the heat exchanger is connected with the steam pocket and is used for cooling high-temperature flue gas in the waste heat recoverer, so that the temperature of the flue gas is within a preset range; and the central ventilation pipe is used for outputting the cooled flue gas outwards. The flue gas temperature in the waste heat recoverer can be regulated and controlled, dioxin is prevented from being generated, additional waste acid is prevented from being generated in the follow-up cooling treatment procedure, the treatment burden of equipment is reduced, and the safety and reliability of use of the equipment are guaranteed.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical equipment, and in particular relates to a waste heat recovery system for chlorine-containing flue gas. Background Art

[0002] High-temperature incineration is the primary method for treating chlorine-containing waste. To ensure complete incineration, the incineration temperature must be greater than 1100°C and the flue gas residence time must be greater than two seconds. Because the flue gas generated after incineration is very hot, waste heat boilers are typically used to recover the heat from the flue gas.

[0003] Currently, flue gas is typically cooled to above 500°C or below 250°C in a waste heat boiler (HRB), followed by rapid cooling to reduce the flue gas temperature and cut off dioxin formation. However, due to the significant variability in the calorific value generated during incineration, the flue gas flow rate after incineration also varies significantly. Furthermore, the flue gas temperature in the HRB cannot be adjusted, resulting in the HRB being unable to effectively recover the flue gas waste heat. Due to poor temperature control, the flue gas from the incineration of chlorine-containing waste may remain between 500°C and 250°C during the recovery process, leading to dioxin formation.

[0004] To address this issue, one company has devised a cooling method that involves rapidly cooling the flue gas by adding a large amount of water to the quench cooler. This method improves the cooling efficiency and prevents dioxin production after the flue gas passes through the quench cooler. However, this method not only fails to address the dioxin problem within the waste heat boiler, but also produces more waste acid after the quench cooler cools, increasing the processing burden on subsequent equipment. Therefore, a waste heat recovery system that can address this issue is urgently needed. Utility Model Content

[0005] The purpose of this utility model is to provide a waste heat recovery system for chlorine-containing flue gas to address the above shortcomings, and to solve the current problems that are difficult to solve. To achieve the above purpose, this utility model provides the following technical solutions:

[0006] A waste heat recovery system for chlorine-containing flue gas, comprising a steam cooling device and a waste heat recovery device; the steam cooling device comprises a steam drum and a steam regulating assembly; the steam regulating assembly is connected to the steam drum and is used to adjust the temperature of cooling water in the steam drum by adjusting the steam pressure in the steam drum; the waste heat recovery device comprises a heat exchanger and a central vent pipe; the heat exchanger is connected to the steam drum and is used to cool the high-temperature flue gas inside the waste heat recovery device so that the temperature of the flue gas is within a preset range; the central vent pipe is used to output the cooled flue gas to the outside.

[0007] Furthermore, the steam drum is arranged above the waste heat recovery device; the steam cooling device also includes a water inlet pipe and a water inlet valve; the water inlet pipe is connected to the inlet end of the steam drum, and the water inlet valve is arranged on the water inlet pipe.

[0008] Furthermore, the bottom of the drum is also provided with a heat exchange water inlet pipe and a heat exchange water outlet pipe connected to the interior of the drum; the heat exchange water inlet pipe is connected to the inlet end of the heat exchanger, and the heat exchange water outlet pipe is connected to the outlet end of the heat exchanger.

[0009] Furthermore, the steam regulating assembly includes a first steam outlet pipe, a second steam outlet pipe, a first steam outlet valve, a second steam outlet valve and a pressure controller; the top of the steam drum is connected to the first steam outlet pipe and the second steam outlet pipe respectively; the first steam outlet valve is arranged on the first steam outlet pipe, and the second steam outlet valve is arranged on the second steam outlet pipe; the pressure controller is electrically connected to the first steam outlet valve and the second steam outlet valve respectively.

[0010] Furthermore, the first steam outlet pipe and the second steam outlet pipe have different pipe diameters.

[0011] Furthermore, a smoke flow regulating valve is provided at the outlet end of the central ventilation pipe.

[0012] Furthermore, a flow controller is provided on the water inlet valve.

[0013] The beneficial effects of the utility model are:

[0014] The utility model discloses a waste heat recovery system for chlorine-containing flue gas, belonging to the technical field of chemical equipment, comprising a steam cooling device and a waste heat recovery device; the steam cooling device comprises a steam drum and a steam regulating assembly; the steam regulating assembly is connected to the steam drum and is used to adjust the temperature of the cooling water in the steam drum by regulating the steam pressure in the steam drum; the waste heat recovery device comprises a heat exchanger and a central vent pipe; the heat exchanger is connected to the steam drum and is used to cool the high-temperature flue gas inside the waste heat recovery device to keep the flue gas temperature within a preset range; the central vent pipe is used to discharge the cooled flue gas. The utility model can regulate the flue gas temperature in the waste heat recovery device to prevent the generation of dioxins, thereby preventing the generation of additional waste acid in subsequent cooling processes, reducing the processing burden of the equipment, and ensuring the safety and reliability of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural diagram of the utility model;

[0016] In the attached figure: 1, central vent pipe; 2, steam drum; 3, heat exchanger; 4, flue gas flow regulating valve; 201, water inlet valve; 202, first steam outlet valve; 203, second steam outlet valve. DETAILED DESCRIPTION

[0017] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the present invention.

[0018] In the description of the present invention, "first feature" and "second feature" may include one or more such features.

[0019] In the description of the present invention, “plurality” means two or more.

[0020] In the description of the present invention, a first feature being “above” or “below” a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact via another feature therebetween.

[0021] In the description of the present invention, a first feature “above”, “above” and “above” a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0022] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," and "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the illustrative use of these terms does not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0023] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods, but the present invention is not limited to the following embodiments.

[0024] Example 1:

[0025] See attached Figure 1. A waste heat recovery system for chlorine-containing flue gas, comprising a steam cooling device and a waste heat recovery device; the steam cooling device comprises a steam drum 2 and a steam regulating assembly; the steam regulating assembly is connected to the steam drum 2, and is used to adjust the temperature of the cooling water in the steam drum 2 by adjusting the steam pressure in the steam drum 2; the waste heat recovery device comprises a heat exchanger 3 and a central vent pipe 1; the heat exchanger 3 is connected to the steam drum 2, and is used to cool the high-temperature flue gas inside the waste heat recovery device so that the temperature of the flue gas is within a preset range; the central vent pipe 1 is used to output the cooled flue gas to the outside. As can be seen from the above structure, the waste heat recovery device is used to receive the high-temperature flue gas generated after the chlorine-containing waste is incinerated in the incinerator, and to recover the waste heat of the high-temperature flue gas. At this time, the high-temperature flue gas will be between 1100℃ and 1200℃. The steam cooling device is used to cool the flue gas entering the waste heat recovery device, and to control the flue gas temperature within a suitable temperature range according to actual needs to prevent the production of dioxins. The steam cooling device includes a steam drum 2 and a steam regulating assembly. Steam drum 2 is connected to an external boiler, and water from the boiler flows into steam drum 2 as cooling water. The steam regulating assembly is also connected to steam drum 2. The cooling water within steam drum 2 is controlled by the steam regulating assembly. Specifically, the steam pressure within steam drum 2 is adjusted to adjust the temperature of the cooling water within steam drum 2, thereby regulating the flue gas temperature within the waste heat recovery unit. The waste heat recovery unit includes a heat exchanger 3 and a central vent pipe 1. Heat exchanger 3 is connected to steam drum 2. The heat exchanger 3 receives cooling water from steam drum 2 and exchanges heat with the high-temperature flue gas within the waste heat recovery unit, thereby cooling the flue gas. Once the flue gas is cooled to a preset temperature range within the waste heat recovery unit, it is discharged through the central vent pipe 1. Specifically, the flue gas temperature within the waste heat recovery unit must be kept above 500°C and below 250°C to avoid temperatures that could produce dioxins. This makes it unnecessary to add new cooling water to the quench cooler in the subsequent process, thus avoiding the problem of waste acid being generated in the subsequent treatment process and increasing the burden on the equipment. Figure 1 In the figure, the solid arrows indicate the direction of flow for the flue gas, while the hollow arrows indicate the direction of flow for the cooling water and its pressurized steam. This utility model adjusts the flue gas temperature in the waste heat recovery device to avoid the temperature conditions that produce dioxins, ensuring that the flue gas does not generate dioxins and pollute the environment when it is discharged. This prevents the generation of additional waste acid in the subsequent cooling process, reduces the processing burden on the equipment, and ensures the safety and reliability of the equipment.

[0026] Example 2:

[0027] See attached Figure 1. On the basis of Example 1, the steam drum 2 is arranged above the waste heat recovery device; the steam cooling device also includes a water inlet pipe and a water inlet valve 201; the water inlet pipe is connected to the inlet end of the steam drum 2, and the water inlet valve 201 is arranged on the water inlet pipe. It can be seen from the above structure that the steam drum 2 is arranged above the waste heat recovery device, which is convenient for saving the overall floor space of the waste heat recovery system. The cooling water burned by the external boiler is input into the steam drum 2 through the water inlet pipe, wherein, by changing the opening and closing of the water inlet valve 201, whether the cooling water is input into the steam drum 2 is controlled. The water inlet valve 201 can also be connected to the external control background, and the opening of the water inlet valve 201 is changed by the control background to control the flow of cooling water input into the steam drum 2 to meet the cooling requirements of the flue gas.

[0028] The bottom of the steam drum 2 is also provided with a heat exchange water inlet pipe and a heat exchange water outlet pipe that communicate with the interior of the steam drum 2. The heat exchange water inlet pipe is connected to the inlet end of the heat exchanger 3, and the heat exchange water outlet pipe is connected to the outlet end of the heat exchanger 3. As can be seen from the above structure, one end of the heat exchange water inlet pipe and one end of the heat exchange water outlet pipe provided at the bottom of the steam drum 2 are respectively connected to the interior of the steam drum 2, while the other ends of the heat exchange water inlet pipe and the other ends of the heat exchange water outlet pipe are respectively connected to the heat exchanger 3 provided inside the waste heat recovery unit. This allows the cooling water within the steam drum 2 to serve as the heat exchange medium within the heat exchanger 3 to heat the high-temperature flue gas entering the waste heat recovery unit. The utility model adjusts the temperature of the cooling water within the steam drum 2 and the temperature of the heat exchange medium within the heat exchanger 3, so that the high-temperature flue gas is cooled to a preset temperature range after heat exchange, thereby preventing the generation of dioxins.

[0029] The steam regulating assembly includes a first steam outlet pipe, a second steam outlet pipe, a first steam outlet valve 202, a second steam outlet valve 203 and a pressure controller; the top of the steam drum 2 is connected to the first steam outlet pipe and the second steam outlet pipe respectively; the first steam outlet valve 202 is arranged on the first steam outlet pipe, and the second steam outlet valve 203 is arranged on the second steam outlet pipe; the pressure controller is electrically connected to the first steam outlet valve 202 and the second steam outlet valve 203 respectively. It can be seen from the above structure that, in response to the need to control the temperature range of the flue gas to above 500°C or below 250°C, a first steam outlet pipe and a second steam outlet pipe are set, and the first steam outlet pipe is independently controlled by the first steam outlet valve 202, and the second steam outlet pipe is independently controlled by the second steam outlet valve 203. The pressure controller is electrically connected to the first steam outlet valve 202 and the second steam outlet valve 203 respectively, and the pressure controller can be connected to the control background. In response to different flue gas cooling requirements, the first steam outlet pipe and / or the second steam outlet pipe are selected to be opened, the steam pressure in the steam drum 2 is adjusted, and the cooling water temperature is controlled, thereby realizing the adjustment of the flue gas temperature in the waste heat recovery device.

[0030] Example 3:

[0031] See attached Figure 1Based on the second embodiment, the first and second steam outlet pipes have different diameters. As can be seen from the above structure, depending on the recovery requirements, the required flue gas temperature range is at least above 500°C or below 250°C. Therefore, setting the diameters of the first and second steam outlet pipes to different diameters can meet the steam pressure regulation requirements in different situations, thereby improving the cooling efficiency of the flue gas.

[0032] The outlet of the central ventilation pipe 1 is also provided with a flue gas flow control valve 4. As can be seen from the above structure, the flue gas flow control valve 4 controls the flue gas output flow rate according to the cooling status of the flue gas in the waste heat recovery unit, ensuring that the flue gas in the waste heat recovery unit is cooled to a preset temperature range before being discharged.

[0033] The water inlet valve 201 is also provided with a flow controller. As can be seen from the above structure, the flow controller can also be connected to an external control background to adjust the opening of the water inlet valve 201 according to the real-time flow of flue gas entering the waste heat recovery device to meet the cooling requirements of the flue gas.

[0034] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A waste heat recovery system for chlorine-containing flue gas, characterized by: It includes a steam cooling device and a waste heat recovery device; the steam cooling device includes a steam drum and a steam regulating component; the steam regulating component is connected to the steam drum and is used to adjust the temperature of the cooling water in the steam drum by adjusting the steam pressure in the steam drum; the waste heat recovery device includes a heat exchanger and a central ventilation pipe; the heat exchanger is connected to the steam drum and is used to cool the high-temperature flue gas inside the waste heat recovery device so that the temperature of the flue gas is within a preset range; the central ventilation pipe is used to output the cooled flue gas to the outside.

2. The waste heat recovery system for chlorine-containing flue gas according to claim 1, characterized in that: The steam drum is arranged above the waste heat recovery device; the steam cooling device also includes a water inlet pipe and a water inlet valve; the water inlet pipe is connected to the inlet end of the steam drum, and the water inlet valve is arranged on the water inlet pipe.

3. The waste heat recovery system for chlorine-containing flue gas according to claim 2, characterized in that: The bottom of the drum is also provided with a heat exchange water inlet pipe and a heat exchange water outlet pipe connected to the interior of the drum; the heat exchange water inlet pipe is connected to the inlet end of the heat exchanger, and the heat exchange water outlet pipe is connected to the outlet end of the heat exchanger.

4. The waste heat recovery system for chlorine-containing flue gas according to claim 2, characterized in that: The steam regulating assembly includes a first steam outlet pipe, a second steam outlet pipe, a first steam outlet valve, a second steam outlet valve and a pressure controller; the top of the steam drum is connected to the first steam outlet pipe and the second steam outlet pipe respectively; the first steam outlet valve is arranged on the first steam outlet pipe, and the second steam outlet valve is arranged on the second steam outlet pipe; the pressure controller is electrically connected to the first steam outlet valve and the second steam outlet valve respectively.

5. The waste heat recovery system for chlorine-containing flue gas according to claim 4, characterized in that: The first steam outlet pipe and the second steam outlet pipe have different pipe diameters.

6. The waste heat recovery system for chlorine-containing flue gas according to claim 1, characterized in that: The outlet end of the central ventilation pipe is also provided with a smoke flow regulating valve.

7. The waste heat recovery system for chlorine-containing flue gas according to claim 2, characterized in that: The water inlet valve is also provided with a flow controller.

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