Waste-to-air heating system for flue gas waste heat in waste incineration power plants

Abstract

This utility model relates to a waste-to-energy incineration power plant flue gas waste heat heating primary air system, including a heat pipe flue gas heat exchanger, an air inlet pipe, a primary air outlet pipe, a steam heater, a cyclone dust collector, an acoustic soot blower, a compressed air purging device, a differential pressure sensor, and a controller. The flue gas heat exchanger utilizes the waste heat of the incineration flue gas to preheat the primary air. The steam heater is used to supplement heating when the flue gas temperature is insufficient. The cyclone dust collector and soot blowing device prevent blockage of the heat exchanger. The differential pressure sensor monitors ash accumulation in real time. The controller achieves intelligent regulation by linking the fan and flue gas valves. This device has a compact structure, high operating efficiency, and can significantly reduce energy consumption and improve incineration efficiency.

Description

Technical Field

[0001] This utility model relates to the field of heat energy recovery and thermal system integration technology, and in particular to a primary air heating system for flue gas waste heat in waste incineration power plants. Background Technology

[0002] In modern waste-to-energy plants, primary air is typically introduced as combustion air and preheated to between 150°C and 250°C to ensure complete combustion of waste in the incinerator, thereby increasing furnace temperature and combustion efficiency. Traditional primary air heating methods often employ steam heat exchangers or electric heaters, but these methods suffer from high energy consumption and operating costs, hindering efficient energy utilization and overall system energy efficiency improvement.

[0003] Meanwhile, with increasingly stringent environmental standards, emissions from waste incineration are subject to stricter controls. Improper primary air temperature control can not only affect combustion stability and efficiency but may also lead to increased formation of harmful gases such as dioxins, further polluting the environment. Currently, there is a lack of heating solutions that can effectively control air temperature while also meeting environmental and energy-saving requirements.

[0004] On the other hand, the flue gas emitted during waste incineration itself has high thermal energy, with temperatures reaching 200-300℃. However, this portion of thermal energy is not fully recovered and utilized in traditional processes. How to efficiently, safely, and stably use this waste heat from the flue gas for primary air heating is a key issue in achieving synergistic utilization of system thermal energy.

[0005] In view of this, the inventor specifically designed a waste incineration power plant flue gas waste heat heating primary air system, which led to this invention. Utility Model Content

[0006] (a) Technical problems to be solved

[0007] The purpose of this application is to provide a primary air heating system for waste incineration power plants using waste heat from flue gas, addressing the problems of high energy consumption, high operating costs, limited heating methods, and poor emission control in the primary air heating process of waste incineration power plants.

[0008] (II) Technical Solution

[0009] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0010] This application provides a waste-to-energy flue gas waste heat heating primary air system for waste incineration power plants, including:

[0011] A flue gas heat exchanger is installed on the flue gas exhaust channel of a waste incinerator. The flue gas heat exchanger is a heat pipe type structure used to heat the air using the waste heat of the flue gas.

[0012] An air inlet pipe is connected at one end to the external environment and at the other end to the air inlet of the flue gas heat exchanger.

[0013] One end of the primary air output pipeline is connected to the air outlet of the flue gas heat exchanger, and the other end is connected to the primary air inlet of the incinerator.

[0014] A steam heater is installed on the primary air output pipeline to supplement the primary air when the flue gas heat exchanger is insufficiently heated.

[0015] A cyclone dust collector is installed before the flue gas inlet of the flue gas heat exchanger to pre-remove particles from the flue gas.

[0016] An acoustic soot blower and a compressed air pulse purging device are installed on the flue gas heat exchanger body for cleaning accumulated ash;

[0017] A differential pressure sensor is installed between the inlet and outlet of the flue gas heat exchanger to monitor the differential pressure and trigger an alarm when the differential pressure exceeds a set value.

[0018] The controller, electrically connected to a fan and a flue gas valve actuator, is used to adjust the primary air temperature according to the combustion load and automatically activate the steam heater when the flue gas temperature is below a preset threshold.

[0019] In a further embodiment, the heat pipe bundle of the heat pipe flue gas heat exchanger can be detachably installed inside the heat exchanger housing.

[0020] In a further embodiment, the steam heater is a shell-and-tube heat exchanger structure, with its steam inlet connected to the main steam pipe of the power plant, and equipped with a regulating valve to control its start and stop.

[0021] In a further embodiment, the outlet of the cyclone dust collector is connected to the flue gas inlet of the flue gas heat exchanger via a pipeline.

[0022] In a further embodiment, the cyclone dust collector is provided with a dust hopper at the bottom and equipped with a timed dust discharge mechanism.

[0023] In a further embodiment, the acoustic soot blower is equipped with an automatic timing controller.

[0024] In a further embodiment, the differential pressure sensor is located between the flue gas inlet pipe and the outlet pipe of the flue gas heat exchanger and is electrically connected to the alarm.

[0025] In a further embodiment, the controller adopts a programmable logic controller (PLC) and has a preset PID control program for linkage control of the fan speed and flue gas valve opening.

[0026] In a further embodiment, the controller is equipped with a safety interlock logic that automatically starts the steam heater for reheating when the detected flue gas temperature is below 100°C.

[0027] (III) Beneficial Effects

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] By integrating heat pipe flue gas heat exchangers, cyclone dust collectors, acoustic soot blowers, differential pressure monitoring systems, and intelligent controllers, a compact, flexible, and efficient primary air heating system has been formed. This system effectively utilizes the waste heat in the waste incineration flue gas to heat the primary air, significantly reducing dependence on steam and electricity, resulting in significant energy savings. At the same time, through multiple anti-clogging and ash removal and linkage control measures, the system ensures long-term stable operation, improves incineration efficiency, and helps reduce flue gas pollution emissions.

[0030] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings. Attached Figure Description

[0031] in:

[0032] Figure 1 This is a schematic diagram of a waste-to-energy power plant flue gas waste heat heating primary air system.

[0033] Label Explanation:

[0034] 110. Air inlet pipe; 120. Primary air outlet pipe; 130. Heat pipe flue gas heat exchanger; 131. Heat exchanger shell; 132. Heat pipe bundle; 140. Steam heater; 150. Cyclone dust collector; 151. Ash hopper; 152. Ash discharge mechanism; 160. Acoustic soot blower; 170. Compressed air pulse purging device; 180. Differential pressure sensor; 190. Controller (PLC); 191. Fan control unit; 192. Flue gas valve drive unit; 193. Temperature judgment and switching logic unit. Detailed Implementation

[0035] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer and more understandable, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0036] like Figure 1As shown, this utility model provides a primary air heating system for waste incineration power plant flue gas waste heat, including modules such as an air path system, a heat exchange system, an auxiliary heating system, a flue gas treatment device, and a monitoring and control unit. The whole system is a primary air heating system with a compact structure, precise control, and reliable operation.

[0037] The air path system includes an air inlet pipe 110 and a primary air outlet pipe 120. The former is used to introduce ambient air, while the latter delivers heated air to the incinerator duct. Before entering the heat exchange system, the air undergoes coarse filtration and flow rate setting to ensure heat exchange efficiency and safe operation of the fan.

[0038] The core of the heat exchange system is a heat pipe flue gas heat exchanger 130, which is installed on the flue gas exhaust duct of the incinerator and uses high-temperature flue gas to exchange heat with the introduced air. The heat exchanger shell 131 is made of corrosion-resistant material and has a replaceable heat pipe bundle 132 inside, which can adapt to the operating environment of flue gas containing corrosive and high dust.

[0039] like Figure 1 As shown, to improve the system's adaptability, a steam heater 140 is connected in series after the heat pipe heat exchanger. This provides supplementary heating when the flue gas temperature is insufficient to complete the heating task during the initial stage of waste incineration or at low load, ensuring that the primary air temperature meets the combustion requirements.

[0040] To prevent the heat pipe heat exchanger from clogging due to flue gas dust, a cyclone dust collector 150 is installed upstream of the flue gas heat exchanger. This dust collector has a dust removal efficiency of over 80%, effectively removing large dust particles and reducing the dust accumulation burden on downstream equipment. Its lower part is equipped with an ash hopper 151 and an ash discharge mechanism 152, which can automatically discharge ash via a timer controller.

[0041] In addition, to prevent dust accumulation on the surface of the heat pipes due to long-term operation, an acoustic soot blower 160 and a compressed air pulse purging device 170 are installed on the heat exchanger. The acoustic soot blower can release high-frequency acoustic pulses at regular intervals to excite the dust on the surface of the heat pipes to fall off, while the compressed air device is used for periodic auxiliary cleaning to improve heat exchange stability.

[0042] During system operation, the pressure difference between the inlet and outlet of the heat exchanger is monitored in real time by the differential pressure sensor 180. Once the pressure difference exceeds the set value, the control system will issue an alarm and start the dust removal procedure to ensure the safety and reliability of the system.

[0043] like Figure 1As shown, the controller 190 is a programmable logic controller (PLC) that integrates a fan control unit 191, a flue gas valve drive unit 192, and a temperature judgment and switching logic unit 193. Based on the deviation between the primary air temperature target and the feedback value, the controller uses a PID algorithm to regulate airflow and activate valves. It also automatically switches to steam heating mode when flue gas heat exchange is insufficient, thereby ensuring stable combustion in the incinerator.

[0044] Overall, this utility model, through the organic combination of the above structures, utilizes the waste heat resources of incineration flue gas to efficiently preheat the primary air, thereby improving incineration efficiency and reducing energy waste. At the same time, through multiple anti-blocking measures and intelligent control, it ensures long-term continuous and stable operation of the system, making it suitable for the energy-saving retrofit needs of various waste incineration power plants.

[0045] The present invention has been described above with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A primary air heating system for flue gas waste heat in a waste incineration power plant, characterized in that, include: A flue gas heat exchanger is installed on the flue gas exhaust channel of a waste incinerator. The flue gas heat exchanger is a heat pipe type structure used to heat the air using the waste heat of the flue gas. An air inlet pipe is connected at one end to the external environment and at the other end to the air inlet of the flue gas heat exchanger. One end of the primary air output pipeline is connected to the air outlet of the flue gas heat exchanger, and the other end is connected to the primary air inlet of the incinerator. A steam heater is installed on the primary air output pipeline to supplement the primary air when the flue gas heat exchanger is insufficiently heated. A cyclone dust collector is installed before the flue gas inlet of the flue gas heat exchanger to pre-remove particles from the flue gas. An acoustic soot blower and a compressed air pulse purging device are installed on the flue gas heat exchanger body for cleaning accumulated ash; A differential pressure sensor is installed between the inlet and outlet of the flue gas heat exchanger to monitor the differential pressure and trigger an alarm when the differential pressure exceeds a set value. The controller, electrically connected to a fan and a flue gas valve actuator, is used to adjust the primary air temperature according to the combustion load and automatically activate the steam heater when the flue gas temperature is below a preset threshold.

2. The waste-to-energy flue gas waste heat heating primary air system for waste incineration power plants according to claim 1, characterized in that, The heat pipe bundle of the heat pipe flue gas heat exchanger can be detachably installed inside the heat exchanger shell.

3. The waste-to-energy flue gas waste heat heating primary air system for waste incineration power plants according to claim 1, characterized in that, The steam heater is a shell-and-tube heat exchanger structure, with its steam inlet connected to the main steam pipe of the power plant, and equipped with a regulating valve to control its start and stop.

4. The waste-to-energy flue gas waste heat heating primary air system for waste incineration power plants according to claim 3, characterized in that, The outlet of the cyclone dust collector is connected to the flue gas inlet of the flue gas heat exchanger via a pipeline.

5. The waste-to-gas waste heat heating primary air system for waste incineration power plants according to claim 1, characterized in that, The bottom of the cyclone dust collector is equipped with a dust hopper and a timed dust discharge mechanism.

6. The waste-to-energy flue gas waste heat heating primary air system according to claim 5, characterized in that, The acoustic soot blower is equipped with an automatic timer controller.

7. The waste-to-energy flue gas waste heat heating primary air system for waste incineration power plants according to claim 1, characterized in that, The differential pressure sensor is located between the flue gas inlet pipe and the outlet pipe of the flue gas heat exchanger and is electrically connected to the alarm.

8. The waste-to-energy flue gas waste heat heating primary air system according to claim 1, characterized in that, The controller uses a programmable logic controller (PLC) and has a preset PID control program for linkage control of fan speed and flue gas valve opening.

9. The waste-to-gas waste heat heating primary air system for waste incineration power plants according to claim 8, characterized in that, The controller is equipped with a safety interlock logic. When the detected flue gas temperature is below 100°C, the steam heater is automatically started for reheating.

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