Waste-to-energy power plant flue gas waste heat heating condensate system

Abstract

This utility model discloses a waste-to-energy flue gas waste heat heating condensate system for waste incineration power plants, including a flue gas inlet pipe, a heat pipe heat exchanger, a soot blowing device, a secondary heating device, an intelligent control system, and an interlocking protection unit. The heat pipe heat exchanger exchanges heat between the high-temperature flue gas discharged from the boiler and the low-temperature condensate, raising the condensate temperature; the soot blowing device removes ash buildup from the heat exchanger; the intelligent control system dynamically adjusts the flue gas flow rate and water pump operation based on temperature and acid dew point parameters; and the interlocking protection unit automatically switches to the steam bypass channel when the temperature is abnormal. This system has the advantages of high heat exchange efficiency, reliable structure, strong corrosion resistance, and intelligent control, making it suitable for energy-saving and environmentally friendly power plants.

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 waste-to-energy power plant flue gas waste heat heating condensate system. Background Technology

[0002] During the operation of waste-to-energy plants, the boiler system emits a large amount of high-temperature flue gas when burning waste, with temperatures typically between 150°C and 250°C. If this flue gas heat is not utilized, it will be directly released into the atmosphere, resulting in a significant waste of recoverable energy and increasing environmental emissions. On the other hand, the condensate temperature in the boiler circulation system is usually only 30°C to 60°C, requiring further heating to above 80°C to meet the needs of deoxygenation and improve thermal cycle efficiency. Traditional condensate heating methods mainly rely on low-pressure steam or electric heating, which not only increases plant energy consumption but also increases the load on the boiler system.

[0003] Existing technologies include solutions for utilizing some of the waste heat from flue gas for low-temperature water heating, but these generally suffer from low heat exchange efficiency, severe dust accumulation, and high corrosion risk. For example, traditional heat exchange equipment often employs shell-and-tube or tube-and-tube structures, which lack good dust resistance and are prone to clogging of the heat transfer surfaces, resulting in a significant decrease in thermal efficiency after a period of operation. Furthermore, when the temperature of the flue gas after heat exchange is below the acid dew point, corrosive condensate is easily generated, leading to a shortened equipment lifespan and increased maintenance costs.

[0004] In view of this, the inventors specifically designed a waste incineration power plant flue gas waste heat heating condensate system, which led to this invention. Utility Model Content

[0005] (a) Technical problems to be solved

[0006] The purpose of this application is to provide a condensate heating system for flue gas waste heat in waste incineration power plants, which solves the problems of inefficient recovery of flue gas waste heat, high energy consumption for boiler condensate heating, and the risks of corrosion and ash accumulation associated with traditional heating methods in waste incineration power plants.

[0007] (II) Technical Solution

[0008] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0009] This application provides a waste-to-energy flue gas waste heat heating condensate system for waste incineration power plants, characterized in that it includes:

[0010] The flue gas inlet pipe is connected to the boiler outlet and is used to guide the flue gas into the system;

[0011] A heat pipe heat exchanger includes a heat exchange shell and multiple sets of heat pipe assemblies disposed within the heat exchange shell. One end of each heat pipe assembly is connected to the flue gas inlet pipe, and the other end is provided with a flue gas outlet pipe. The heat pipe assembly is made of corrosion-resistant material.

[0012] The heat pipe heat exchanger is provided with a first water inlet and a first water outlet. The first water inlet is used to receive condensate at a temperature of 30~60℃, and the first water outlet is used to output condensate after the temperature has been increased.

[0013] The soot blowing device includes a rotary soot blower and a shock wave soot blower, both of which are located in the flue gas passage area of ​​the heat pipe heat exchanger and are used to periodically remove adhering dust.

[0014] The secondary heating device includes a steam pipe connected to the first water outlet for further heating the preheated condensate;

[0015] The intelligent control system includes a temperature sensor, an acid dew point monitoring device, and a controller. The temperature sensor is respectively installed in the flue gas outlet pipe and the first water outlet. The controller is connected to the temperature sensor, the flue gas regulating valve, and the water pump, and is used to regulate the flue gas flow rate and the water pump speed.

[0016] An interlocking protection unit is used to automatically switch the flue gas passage to a steam bypass passage when the flue gas outlet temperature is lower than a set threshold.

[0017] In a further embodiment, the surface of the heat pipe assembly is provided with an Al2O3-TiO2 nano-ceramic anti-corrosion coating.

[0018] In a further embodiment, the heat pipe assembly is a 316L stainless steel tube.

[0019] In a further embodiment, the first water outlet is connected to a deaerator inlet.

[0020] In a further embodiment, the rotary sootblower in the sootblowing device is equipped with a timing control module to control the sootblowing cycle to not exceed 8 hours.

[0021] In a further embodiment, the controller employs a PID control algorithm and is connected to a Siemens PCS7 control module.

[0022] In a further embodiment, the controller is connected to an SO3 content monitoring device.

[0023] In a further embodiment, the interlocking protection unit is equipped with a bypass switching valve.

[0024] In a further embodiment, the steam bypass channel is connected to the secondary heating device, and the condensate temperature is raised to not less than 85°C by steam heating.

[0025] (III) Beneficial Effects

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] By adopting a heat pipe heat exchanger structure with excellent corrosion resistance, a dual soot blowing cleaning mechanism, and an intelligent interlocking control system, the efficiency of flue gas waste heat recovery is significantly improved, the dependence of traditional condensate heating on low-pressure steam and electric heating is reduced, and the problems of acid dew point corrosion and ash accumulation blockage are effectively avoided. This not only extends the service life of the equipment and reduces the operating and maintenance costs, but also achieves energy saving, high efficiency and safety in system operation.

[0028] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings. Attached Figure Description

[0029] in:

[0030] Figure 1 This is a schematic diagram of a waste-to-energy power plant flue gas waste heat heating condensate system.

[0031] Label Explanation:

[0032] 110. Flue gas inlet pipe; 120. Heat pipe heat exchanger; 121. Heat exchange shell; 122. Heat pipe assembly; 123. Flue gas outlet pipe; 124. First water inlet; 125. First water outlet; 130. Soot blowing device; 131. Rotary soot blower; 132. Shock wave soot blower; 140. Secondary heating device; 141. Steam pipe; 150. Intelligent control system; 151. Temperature sensor; 152. Acid dew point monitoring device; 153. Controller; 160. Interlock protection unit; 161. Bypass switching valve; 162. Steam bypass channel; 170. Deaerator. Detailed Implementation

[0033] 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.

[0034] like Figure 1 As shown in the figure, this utility model embodiment provides a waste incineration power plant flue gas waste heat heating condensate system, which has a compact structure, high thermal efficiency, and reliable operation. It can realize the efficient utilization of flue gas waste heat, while ensuring the stability of the condensate heating process and meeting corrosion prevention requirements.

[0035] The system mainly includes a flue gas inlet pipe 110, a heat pipe heat exchanger 120, a soot blowing device 130, a secondary heating device 140, an intelligent control system 150, and an interlock protection unit 160. The entire system is located between the flue gas emission path and the condensate recovery path at the tail end of the boiler, forming a closed and efficient heat exchange process.

[0036] like Figure 1 As shown, specifically, the high-temperature flue gas at the boiler outlet is first introduced into the heat pipe heat exchanger 120 through the flue gas inlet pipe 110. The heat pipe heat exchanger includes a heat exchange shell 121 and multiple sets of heat pipe assemblies 122. The heat pipe assemblies are made of 316L stainless steel or a material with an Al2O3-TiO2 nano-ceramic anti-corrosion layer sprayed on the surface, which has both excellent heat resistance and corrosion resistance. The flow velocity of the flue gas inside the heat exchanger is controlled at 812 m / s, which can effectively prevent dust accumulation. At the same time, condensate is introduced from the first water inlet 124 and flows in the pipe at a speed of 1.5-2.5 m / s to avoid vaporization or water hammer. After being heated, it flows out from the first water outlet 125.

[0037] To maintain heat exchange efficiency and extend equipment life, the heat pipe heat exchanger is equipped with a soot blowing device 130, which includes a rotary soot blower 131 and a shock wave soot blower 132, which can respectively realize timed and efficient soot cleaning functions. The soot blowing system has control logic, the cycle does not exceed 8 hours, and it can be linked with the control system to implement dynamic cleaning strategies.

[0038] To ensure that the final outlet temperature of the condensate meets the operating requirements of the deaerator, a secondary heating device 140 is connected in series after the first water outlet. This device introduces low-pressure steam through a steam pipe 141 for supplemental heating, further heating the condensate to no less than 85°C, and then sending it to the inlet of the deaerator 170 for subsequent treatment.

[0039] like Figure 1 As shown, at the system control level, an intelligent control system 150 is set up, including a temperature sensor 151, an acid dew point monitoring device 152, and a controller 153, which are used to collect information on the temperature, flow rate, and acidic components of flue gas and water flow. The controller integrates a PID control algorithm and can be connected to a Siemens PCS7 or equivalent industrial control platform to achieve precise adjustment of key parameters such as flue gas regulating valves and water pump speeds.

[0040] In addition, to address the acid dew point corrosion problem caused by flue gas temperature fluctuations, the system is also equipped with an interlock protection unit 160. When the temperature sensor detects that the flue gas outlet temperature is lower than the set threshold (such as 110°C), the controller immediately triggers the bypass switching valve 161 to introduce the flue gas into the steam bypass channel 162, temporarily stopping the flue gas heat exchange process, thereby avoiding corrosion of the internal structure of the heat exchanger by acidic condensate.

[0041] This invention significantly reduces low-pressure steam consumption and plant power consumption through cascade recovery of flue gas waste heat. Combined with intelligent control and multiple protection designs, it achieves a harmonious balance between economic efficiency, reliability, and environmental benefits. The system is suitable for various medium and large-scale waste-to-energy plants and can be modularly adjusted and expanded according to actual operating conditions.

[0042] 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 waste-to-energy incineration power plant flue gas waste heat heating condensate system, characterized in that, include: The flue gas inlet pipe is connected to the boiler outlet and is used to guide the flue gas into the system; A heat pipe heat exchanger includes a heat exchange shell and multiple sets of heat pipe assemblies disposed within the heat exchange shell. One end of each heat pipe assembly is connected to the flue gas inlet pipe, and the other end is provided with a flue gas outlet pipe. The heat pipe assembly is made of corrosion-resistant material. The heat pipe heat exchanger is provided with a first water inlet and a first water outlet. The first water inlet is used to receive condensate at a temperature of 30~60℃, and the first water outlet is used to output condensate after the temperature has been increased. The soot blowing device includes a rotary soot blower and a shock wave soot blower, both of which are installed in the flue gas passage area of ​​the heat pipe heat exchanger for periodically removing adhering dust. The secondary heating device includes a steam pipe connected to the first water outlet for further heating the preheated condensate; The intelligent control system includes a temperature sensor, an acid dew point monitoring device, and a controller. The temperature sensor is respectively installed in the flue gas outlet pipe and the first water outlet. The controller is connected to the temperature sensor, the flue gas regulating valve, and the water pump, and is used to regulate the flue gas flow rate and the water pump speed. An interlocking protection unit is used to automatically switch the flue gas passage to a steam bypass passage when the flue gas outlet temperature is lower than a set threshold.

2. The waste-to-energy flue gas waste heat heating condensate system according to claim 1, characterized in that, The heat pipe assembly has an Al2O3-TiO2 nano-ceramic anti-corrosion coating on its pipe wall surface.

3. The waste-to-energy flue gas waste heat heating condensate system according to claim 1, characterized in that, The heat pipe assembly is made of 316L stainless steel.

4. The waste-to-energy flue gas waste heat heating condensate system according to claim 1, characterized in that, The first water outlet is connected to a deaerator inlet.

5. The waste-to-energy flue gas waste heat heating condensate system according to claim 1, characterized in that, The rotary soot blower in the soot blowing device is equipped with a timer control module to control the soot blowing cycle to not exceed 8 hours.

6. The waste-to-energy flue gas waste heat heating condensate system according to claim 1, characterized in that, The controller uses a PID control algorithm and is connected to a Siemens PCS7 control module.

7. The waste-to-energy flue gas waste heat heating condensate system according to claim 1 or 6, characterized in that, The controller is connected to an SO3 content monitoring device.

8. The waste-to-energy flue gas waste heat heating condensate system according to claim 1, characterized in that, The interlocking protection unit is equipped with a bypass switching valve.

9. The waste-to-energy flue gas waste heat heating condensate system according to claim 8, characterized in that, The steam bypass channel is connected to the secondary heating device and raises the condensate temperature to no less than 85°C through steam heating.

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