Boiler blow-off waste heat recovery device

Abstract

The utility model relates to the technical field of boilers, in particular to a boiler blow-off waste heat recovery device which comprises a steam boiler, a combustion engine installed on a combustion chamber of the steam boiler, a front valve, a buffer tank, a heat exchanger and a rear valve, and the front valve, the buffer tank, the heat exchanger and the rear valve are sequentially connected to the blow-off end of the steam boiler. A cold water pipe and a hot water pipe are installed on the heating side of the heat exchanger and connected with the water tank. The opening degree of the valve is adjusted in real time and the heat exchange efficiency is improved by combining the heat change of the pollution discharge end with the temperature sensing deformation piece and the linkage assembly.

Description

Technical Field

[0001] This utility model relates to the field of boiler technology, and in particular to a boiler blowdown waste heat recovery device. Background Technology

[0002] During operation, boilers generate high-temperature wastewater containing a significant amount of heat energy. Traditional boiler waste heat recovery systems typically employ a fixed-load design, transferring the heat from the wastewater to softened water via a heat exchanger.

[0003] Fixed load design cannot dynamically adjust the flow rate of the heat exchanger according to the fluctuation of sewage temperature, resulting in insufficient heat utilization in the high-temperature section and insufficient heat exchange in the low-temperature section, resulting in a low overall heat recovery rate. Existing technologies mostly rely on manual adjustment of valve opening, which has a slow response speed and cannot adapt to changes in sewage temperature in real time. Furthermore, the adjustment devices using electronic systems are easily damaged in high-temperature environments.

[0004] Therefore, a boiler blowdown heat recovery device driven by mechanical linkage and temperature-sensing deformation components can be designed to adjust the flow rate of the heat exchanger in real time, so that the heat of the wastewater can be fully exchanged and the heat loss can be reduced. Utility Model Content

[0005] To overcome the problem that the heat exchanger load is fixed and heat loss is large when the boiler is blown out, and it cannot be adjusted automatically.

[0006] The technical solution of this utility model is as follows: a boiler blowdown waste heat recovery device, comprising a steam boiler, a burner installed in the combustion chamber of the steam boiler, a pre-valve, a buffer tank, a heat exchanger, and a post-valve sequentially connected to the blowdown end of the steam boiler, a water tank connected to the water inlet end of the steam boiler, and cold water pipes and hot water pipes installed on the heating side of the heat exchanger, both of which are connected to the water tank; a linkage assembly is installed between the pre-valve and the post-valve, a transmission assembly is slidably installed on the blowdown end of the heat exchanger, the input end of the linkage assembly is connected to the output end of the transmission assembly, and a temperature-sensing deformation element is installed on the blowdown end of the heat exchanger. The system includes a temperature sensor, a transmission assembly connected to a temperature-sensing deformable component, and a transmission assembly that expands and deforms to drive the transmission assembly. As the transmission assembly moves, the linkage assembly increases or decreases the opening of the pre-valve and post-valve. A variable frequency water pump can be configured on the heating side of the heat exchanger to heat liquids such as water (two pumps can be configured as needed, one for operation and one for standby). Temperature sensors are installed at the inlet of the buffer tank and the wastewater outlet of the heat exchanger. A water pump and a heat meter are configured on the heating side of the heat exchanger. The heat meter has two built-in temperature sensors, installed on the cold water pipe and the hot water pipe respectively. The cold water pipe temperature sensor is installed at the inlet of the water pump. The entire system is equipped with a PLC-based control unit (programmable controller for controlling electrical equipment such as water pumps and temperature sensors). The control unit includes a PLC controller, a smart meter, and a frequency converter. Temperature sensors at the wastewater inlet and outlet are connected to the control unit via hard-wired analog signals.

[0007] Preferably, the linkage assembly includes sprockets respectively mounted on the pre-valve and the post-valve, a linkage gear mounted on one of the sprockets, and a chain belt meshing with the two sprockets. The linkage gear is connected to the transmission assembly, which drives the linkage gear to rotate. The linkage gear drives the pre-valve and the post-valve to rotate simultaneously through the sprockets and the chain belt, thereby controlling the simultaneous adjustment of the opening degree of the pre-valve and the post-valve (expanding or shrinking). When both valves expand simultaneously, the amount of wastewater discharged per unit time by the steam boiler increases; when both valves shrink simultaneously, the amount of wastewater discharged per unit time by the steam boiler decreases. In this technical solution, the main function is to adjust and shrink the opening degree of the pre-valve and the post-valve to reduce the flow rate per unit time, so that the heat exchanger can fully exchange the heat of the wastewater.

[0008] Preferably, the transmission assembly includes a slip ring slidably connected to the drain end of the heat exchanger and a rack fixedly connected to the slip ring. The rack meshes with a linkage gear. A temperature-sensitive deformation element is used to drive the slip ring and rack to move. When the rack moves, the linkage gear rotates.

[0009] Preferably, the temperature-sensing deformation component includes a corrugated SMA plate installed on the drain end of the heat exchanger, a push head installed on one end of the SMA plate, and an assembly head detachably installed on the push head. The assembly head is detachably installed on the slip ring. When the SMA plate deforms, the push head and the assembly head drive the slip ring to move. (The detachable installation of the assembly head and the push head allows them to be removed independently when not in use, disconnecting the connection between the temperature-sensing deformation component and the transmission assembly, preventing the opening of the pre-valve and post-valve from automatically adjusting due to temperature changes.)

[0010] Preferably, a filter spring is installed on the temperature-sensing deformable part. One end of the filter spring is connected to the push head, and the other end is connected to the SMA plate. The filter spring is added between the temperature-sensing deformable part and the push head to filter short-term temperature fluctuations. Similar to the anti-vibration design of pneumatic regulating valves, for example, when the temperature fluctuates slightly, the expansion force of the temperature-sensing deformable part will be absorbed by the filter spring, and will not generate stress on the transmission components, thus avoiding the incorrect adjustment of the opening of the front valve and the rear valve due to slight temperature fluctuations.

[0011] Preferably, the waste heat recovery device is equipped with an air supply component, and a cleaning component is installed on the air supply component. The input end of the air supply component is connected to the linkage component. When the linkage component moves, the gas flows between the air supply component and the cleaning component. The cleaning component is used to guide the gas to the transmission component.

[0012] Preferably, the air supply assembly includes an air chamber installed on the drain end of the heat exchanger and a piston movably connected in the air chamber. The piston is mounted on a slip ring, and when the slip ring moves, it drives the piston to move in the air chamber and controls the flow of gas between the air chamber and the cleaning assembly.

[0013] Preferably, the cleaning component includes a duct connected to the air chamber at one end and an air hole opened on the duct. The duct is located on one side of the linkage component. When the gas in the air chamber flows into the duct, it flows to the linkage component through the air hole.

[0014] The beneficial effects of this utility model are:

[0015] 1. By combining the heat changes at the drain end with the setting of temperature-sensing deformation components and linkage components, the valve opening is adjusted in real time to improve heat exchange efficiency;

[0016] 2. The filter spring absorbs short-term temperature fluctuation stress, avoids malfunction, and enhances system stability;

[0017] 3. The air chamber-piston linkage air duct blows the chain belt or synchronous belt, reducing wear on the mechanical structure, improving operational stability, and extending service life. Attached Figure Description

[0018] Figure 1 The diagram shown is a structural schematic of the boiler blowdown waste heat recovery device of this utility model.

[0019] Figure 2 The diagram shown is a schematic representation of the linkage component of the boiler blowdown waste heat recovery device of this utility model.

[0020] Figure 3 The diagram shown is a cross-sectional view of the boiler blowdown waste heat recovery device of this utility model.

[0021] Figure 4 The diagram shown is a cross-sectional view of the boiler blowdown waste heat recovery device of this utility model.

[0022] Figure 5 The diagram shown is a schematic representation of the temperature-sensing deformation component of the boiler blowdown waste heat recovery device of this utility model.

[0023] Figure 6 The diagram shown is a schematic representation of the linkage and transmission components of the boiler blowdown waste heat recovery device of this utility model.

[0024] Figure 7 The diagram shown is a schematic representation of another embodiment of the linkage component of the boiler blowdown waste heat recovery device of this utility model.

[0025] Explanation of reference numerals in the attached drawings: 1. Burner; 2. Steam boiler; 31. Pre-valve; 32. Post-valve; 4. Buffer tank; 5. Heat exchanger; 51. Cold water pipe; 52. Hot water pipe; 6. Water tank; 7. Control unit; 801. Sprocket; 802. Linkage gear; 803. Chain belt; 901. Slip ring; 902. Rack; 1001. Temperature-sensing deformation component; 1002. Push head; 1003. Assembly head; 1004. Filter spring; 1101. Air chamber; 1102. Piston; 1201. Air duct; 1202. Air hole; 1301. Synchronous pulley; 1302. Synchronous belt. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] Please see Figure 1 - Figure 7This utility model provides an embodiment: a boiler blowdown waste heat recovery device, including a steam boiler 2, a burner 1 installed on the combustion chamber of the steam boiler 2, a pre-valve 31, a buffer tank 4, a heat exchanger 5 (the heat exchanger 5 is a plate-type asymmetric high-efficiency heat exchanger 5, the main body material is 316L stainless steel, this type of heat exchanger 5 has high efficiency, corrosion resistance, large sewage side channel, low sewage resistance, and is not easy to block) and a post-valve 32 connected to the blowdown end of the steam boiler 2. A water tank 6 is connected to the water inlet end of the steam boiler 2. Cold water pipe 51 and hot water pipe 52 are installed on the heating side of the heat exchanger 5, and both cold water pipe 51 and hot water pipe 52 are connected to the water tank 6. A linkage component is installed between the pre-valve 31 and the post-valve 32. A transmission component is slidably installed on the blowdown end of the heat exchanger 5. The input end of the linkage component is connected to the output end of the transmission component. A temperature-sensing deformation component 1001 and a temperature sensor are installed on the blowdown end of the heat exchanger 5. The transmission component and the temperature-sensing deformation component 1001 are connected to each other. 1. The temperature-sensing deformation component 1001 expands and deforms, driving the transmission component to move. When the transmission component moves, the linkage component drives the opening of the front valve 31 and the rear valve 32 to increase or decrease. The heating side of the heat exchanger 5 can be equipped with a variable frequency water pump to heat the water and other liquids that need to be heated (two water pumps 7 can be configured as needed, one for use and one for standby. The control unit 7 of the PLC logic dynamically adjusts the water pump frequency according to the outlet temperature of the cold water pipe 51: when the temperature sensor detects that the temperature of the cold water pipe 51 is lower than the set value T1, the frequency converter 11 increases the water pump speed to the preset value P1; when the temperature reaches T2, it automatically switches to the standby pump and reduces the speed to the preset value P2 to ensure the balance between heat exchange efficiency and energy consumption). Temperature sensors are configured at the inlet of the buffer tank 4 and the sewage outlet of the heat exchanger 5. The heating side of the heat exchanger 5 is equipped with a water pump and a heat meter. The heat meter has two temperature sensors, which are installed on the cold water pipe 51 and the hot water pipe 52 respectively. The temperature sensor of the cold water pipe 51 is installed at the inlet of the water pump. The entire system is equipped with a PLC-based control unit 7 (programmable controller, used to control electrical equipment such as water pumps and temperature sensors). Control unit 7 contains a PLC controller, smart meters, and frequency converter 11. Temperature sensors at the wastewater inlet and outlet are connected to control unit 7 via hard-wired analog signals.

[0028] Please see Figure 2 - Figure 6In this embodiment, the linkage component includes sprockets 801 respectively mounted on the front valve 31 and the rear valve 32, a linkage gear 802 mounted on one of the sprockets 801, and a chain belt 803 meshing with the two sprockets 801. The linkage gear 802 is connected to the transmission component, which drives the linkage gear 802 to rotate. The linkage gear 802 drives the front valve 31 and the rear valve 32 to rotate simultaneously through the sprockets 801 and the chain belt 803. This controls the simultaneous adjustment of the opening degree of the front valve 31 and the rear valve 32 (expanding or shrinking). When they expand simultaneously, the amount of sewage discharged per unit time by the steam boiler 2 increases; when they shrink simultaneously, the amount of sewage discharged per unit time by the steam boiler 2 decreases. In this technical solution, the main function is to adjust and shrink the opening degree of the front valve 31 and the rear valve 32 to reduce the flow rate per unit time, so that the heat exchanger 5 can fully exchange the heat of the sewage. The transmission assembly includes a slip ring 901 slidably connected to the drain end of the heat exchanger 5 and a rack 902 fixedly connected to the slip ring 901. The rack 902 meshes with the linkage gear 802. The temperature-sensing deformation member 1001 is used to drive the slip ring 901 and the rack 902 to move. When the rack 902 moves, the linkage gear 802 rotates. The temperature-sensitive deformation component 1001 includes a corrugated SMA plate (the corrugated structure can achieve large lateral deformation, the corrugated design reduces local stress and improves fatigue life) installed on the drain end of the heat exchanger 5. The corrugated SMA plate is woven from nickel-titanium alloy wire and formed into a periodic corrugated structure with wavelength λ=20mm and amplitude A=5mm after solution treatment at 550℃, a push head 1002 installed at one end of the SMA plate, and an assembly head 1003 detachably installed on the push head 1002. The assembly head 1003 is detachably installed on the slip ring 901. When the SMA plate deforms, the push head 1002 and the assembly head 1003 drive the slip ring 901 to move. (The detachable installation of the assembly head 1003 and the push head 1002 allows them to be removed independently when not in use, disconnecting the connection between the temperature-sensitive deformation component 1001 and the transmission assembly, preventing the opening of the pre-valve 31 and the post-valve 32 from automatically adjusting due to temperature changes.)A filter spring 1004 is installed on the temperature-sensing deformable part 1001. One end of the filter spring 1004 is connected to the push head 1002, and the other end is connected to the SMA plate. The filter spring 1004 is added between the temperature-sensing deformable part 1001 and the push head 1002 to filter short-term temperature fluctuations. It is similar to the anti-vibration design of pneumatic regulating valves. For example, when the temperature fluctuates slightly, the expansion force of the temperature-sensing deformable part 1001 will be absorbed by the filter spring 1004, and will not generate stress on the transmission components. This avoids the opening of the front valve 31 and the rear valve 32 being erroneously adjusted due to slight temperature fluctuations (axial deformation is achieved by using the thermal expansion coefficient or phase change characteristics of the material. The deformation of the SMA must meet the maximum deformation of the SMA. Temperature and opening are linearly related. The maximum opening limit of the valve is set. In actual design, the temperature-opening curve is calibrated by experiment. For example, when ΔTmax=120∘C, the opening reaches 100%).

[0029] Please refer to another embodiment based on the linkage component. Figure 1 and Figure 7 The synchronous pulley 1301 replaces the sprocket 801, and the synchronous belt 1302 replaces the chain belt 803. The synchronous adjustment of the opening degree of the front valve 31 and the rear valve 32 is achieved by friction transmission between the synchronous pulley 1301 and the synchronous belt 1302. The friction transmission structure of the synchronous belt 1302 and the synchronous pulley 1301 results in less mechanical vibration because there is almost no mechanical clearance, and the transmission ratio is more stable (it is worth noting that the synchronous belt 1302 needs to be made of high temperature resistant material).

[0030] Please see Figure 2 - Figure 5In this embodiment, an air conveying assembly is installed on the waste heat recovery device, and a cleaning assembly is installed on the air conveying assembly. The input end of the air conveying assembly is connected to the linkage assembly. When the linkage assembly moves, gas flows between the air conveying assembly and the cleaning assembly. The cleaning assembly is used to guide the gas to the transmission assembly. The air conveying assembly includes an air chamber 1101 installed on the drain end of the heat exchanger 5 and a piston 1102 movably connected in the air chamber 1101. The piston 1102 is installed on a slip ring 901. When the slip ring 901 moves, it drives the piston 1102 to move in the air chamber 1101 and controls the gas flow between the air chamber 1101 and the cleaning assembly. The cleaning component includes a duct 1201 connected at one end to the air chamber 1101 and an air hole 1202 opened on the duct 1201. The duct 1201 is located on one side of the linkage component. When the gas in the air chamber 1101 flows into the duct 1201, it flows to the linkage component through the air hole 1202. In actual application, two ducts 1201 are provided, which are respectively connected to the two ends of the air chamber 1101. That is to say, no matter which side the piston 1102 moves to, a part of the gas in the air chamber 1101 will flow into the duct 1201. No matter whether the opening degree of the front valve 31 and the rear valve 32 increases or decreases, the gas can flow to the linkage component through the air hole 1202 to achieve the effect of wind-driven cleaning.

[0031] Working principle: The wastewater from steam boiler 2 first enters buffer tank 4. The main function of buffer tank 4 is to stabilize pressure, reduce impact, and protect heat exchanger 5. The wastewater then enters heat exchanger 5 for heat exchange. After heat exchange, the wastewater is discharged (water is taken from the softened water tank 6 of steam boiler 2, and the waste heat is recovered through an integrated intelligent wastewater discharge heat recovery device to heat the softened water, thereby increasing the boiler feedwater temperature, reducing the natural gas consumption of steam boiler 2, and achieving energy saving). A temperature-sensing deformation element 1001 of appropriate size is set according to the appropriate temperature of the wastewater at the discharge end (for example, when the temperature at the discharge end reaches the threshold F1, the filter spring...). When the stress value of the temperature-sensitive deformation component 1001 reaches its maximum, as the temperature continues to rise, the deformation of the temperature-sensitive deformation component 1001 continues to increase. The assembly head 1003 and the push head 1002 push the slip ring 901 to move. Then, the meshing transmission of the rack 902 and the linkage gear 802 controls the opening of the front valve 31 and the rear valve 32 to be adjusted simultaneously. While the slip ring 901 moves, it drives the piston 1102 to move in the air chamber 1101, so that the gas flows into the air duct 1201 and is finally discharged from the air hole 1202 to blow and clean the chain belt 803 (or synchronous belt 1302).

Claims

1. A boiler blowdown waste heat recovery apparatus, characterized by: It includes a steam boiler (2), a burner (1) installed on the combustion chamber of the steam boiler (2), a pre-valve (31), a buffer tank (4), a heat exchanger (5) and a post-valve (32) connected in sequence to the drain end of the steam boiler (2). The water inlet end of the steam boiler (2) is connected to a water tank (6). The heating side of the heat exchanger (5) is equipped with a cold water pipe (51) and a hot water pipe (52). Both the cold water pipe (51) and the hot water pipe (52) are connected to the water tank (6). A linkage assembly is installed between the pre-valve (31) and the post-valve (32). A transmission assembly is slidably installed on the drain end of the heat exchanger (5). The input end of the linkage assembly is connected to the output end of the transmission assembly. A temperature-sensing deformable element (1001) and a temperature sensor are installed on the drain end of the heat exchanger (5). The transmission assembly is connected to the temperature-sensing deformable element (1001). The temperature-sensing deformable element (1001) expands and deforms and drives the transmission assembly to move. When the transmission assembly moves, the linkage assembly drives the opening degree of the pre-valve (31) and the post-valve (32) to increase or decrease.

2. A boiler blowdown heat recovery device according to claim 1, characterised in that: The linkage assembly includes sprockets (801) respectively mounted on the front valve (31) and the rear valve (32), a linkage gear (802) mounted on one of the sprockets (801), and a chain belt (803) meshing with the two sprockets (801). The linkage gear (802) is connected to the transmission assembly, which is used to drive the linkage gear (802) to rotate. The linkage gear (802) drives the front valve (31) and the rear valve (32) to rotate simultaneously through the sprocket (801) and the chain belt (803).

3. A boiler blowdown heat recovery device according to claim 2, characterised in that: The transmission assembly includes a slip ring (901) slidably connected to the drain end of the heat exchanger (5) and a rack (902) fixedly connected to the slip ring (901). The rack (902) meshes with the linkage gear (802). The temperature-sensitive deformation member (1001) is used to drive the slip ring (901) and the rack (902) to move. When the rack (902) moves, the linkage gear (802) rotates.

4. A boiler blowdown heat recovery device according to claim 3, characterised in that: The temperature-sensitive deformation component (1001) includes a corrugated SMA plate installed on the drain end of the heat exchanger (5), a push head (1002) installed on one end of the SMA plate, and an assembly head (1003) detachably installed on the push head (1002). The assembly head (1003) is detachably installed on the slip ring (901). When the SMA plate deforms, the slip ring (901) is driven to move by the push head (1002) and the assembly head (1003).

5. A boiler blowdown heat recovery device according to claim 4, characterised in that: A filter spring (1004) is installed on the temperature-sensitive deformation part (1001). One end of the filter spring (1004) is connected to the push head (1002), and the other end is connected to the SMA plate.

6. A boiler blowdown heat recovery device according to claim 4, wherein: The waste heat recovery device is equipped with an air supply component, which is also equipped with a cleaning component. The input end of the air supply component is connected to the linkage component. When the linkage component moves, the gas flows between the air supply component and the cleaning component. The cleaning component is used to guide the gas to the transmission component.

7. A boiler blowdown waste heat recovery device according to claim 6, characterized in that: The air supply assembly includes an air chamber (1101) installed on the drain end of the heat exchanger (5) and a piston (1102) movably connected in the air chamber (1101). The piston (1102) is mounted on a slip ring (901). When the slip ring (901) moves, it drives the piston (1102) to move in the air chamber (1101) and controls the flow of gas between the air chamber (1101) and the cleaning assembly.

8. A boiler blowdown heat recovery device according to claim 7, characterised in that: The cleaning component includes a duct (1201) connected at one end to the air chamber (1101) and an air hole (1202) opened on the duct (1201). The duct (1201) is located on one side of the linkage component. When the gas in the air chamber (1101) flows into the duct (1201), it flows to the linkage component through the air hole (1202).

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