Reduction furnace waste heat efficient utilization system

Abstract

The utility model discloses an efficient waste heat utilization system of a reduction furnace, which belongs to the technical field of waste heat reutilization and comprises a filter, a TCS vaporization system, an H2 heater and a TCS preheater. An outlet in the chassis is communicated with a hot stroke channel of the filter, hot stroke channels of the filter, the TCS vaporization system, the H2 heater and the TCS preheater are communicated in sequence, cold stroke channels of the TCS preheater and the TCS vaporization system are communicated in sequence and then are communicated with an inlet in the chassis, and a cold stroke channel of the H2 heater is also communicated with the inlet in the chassis. According to the efficient waste heat utilization system for the reduction furnace disclosed by the utility model, on one hand, SiHCl3 can be heated for multiple times through multiple times of utilization of tail gas heat, and on the other hand, the temperature difference between the tail gas and the SiHCl3 in each link is controlled within a certain range, and when the tail gas passes through the TCS preheater, the tail gas has a lower temperature, so that the tail gas has a lower temperature when being discharged, and the tail gas is prevented from being polluted. Therefore, heat waste can be effectively reduced, and the utilization rate of waste heat of the reduction furnace is effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of waste heat recycling, and in particular to a system for efficiently utilizing waste heat of a reduction furnace. Background Art

[0002] The modified Siemens method is the mainstream technology for producing polysilicon in the world, and its core equipment is the reduction furnace. The working principle of the reduction furnace is to react the mixed gas of trichlorosilane and hydrogen to generate polysilicon and deposit it on the silicon core by electrifying the high-temperature silicon core. The reaction materials of the reduction furnace enter the reduction furnace from the chassis. The reaction in the furnace uses the silicon core at about 1050°C as a carrier, and chemical vapor deposition occurs on the surface. The reaction consumes a lot of electricity to heat to the reaction temperature. In order to protect the reduction furnace and increase the service life of the reduction furnace, the temperature of the furnace body and the chassis should not be too high. Excessive temperature not only affects the life of the equipment, but also poses a safety hazard. Therefore, the reduction furnace and the chassis must be continuously cooled. In this process, the excess heat is taken away by the cooling water of the reduction furnace, resulting in energy waste. The cooling water takes away the high-temperature circulating water and cools it through the heat exchanger, and then sends it to the reduction furnace bell, chassis, electrode and reduction furnace tail gas for cooling.

[0003] The waste heat utilization process is to recycle the heat of high-temperature circulating water and high-temperature exhaust gas that needs to be cooled through corresponding process flows. The overall efficiency of the currently restored waste heat utilization system is average. Utility Model Content

[0004] The utility model discloses a system for efficiently utilizing waste heat from a reduction furnace, so as to improve the above-mentioned problems.

[0005] The technical solution adopted by the utility model to solve the above technical problems is:

[0006] Based on the above-mentioned purpose, the utility model discloses a system for efficiently utilizing waste heat of a reduction furnace, which is used for reusing the waste heat of a reduction furnace. The reduction furnace includes a bell jar, a chassis and an electrode. The bell jar cover is connected to the chassis, the electrode is installed on the chassis, and an inlet and an outlet are provided on the chassis. The system includes a filter, a TCS vaporization system, an H2 heater and a TCS preheater. The input end of the filter is connected to the outlet of the chassis, the output end of the filter is connected to the hot path channel of the TCS vaporization system, the hot path channel of the TCS vaporization system is connected to the hot path channel of the H2 heater, the hot path channel of the H2 heater is connected to the hot path channel of the TCS preheater, the cold path channel of the H2 heater is connected to the inlet of the chassis, the cold path channel of the TCS preheater is connected to the cold path channel of the TCS vaporization system, and the cold path channel of the TCS vaporization system is connected to the inlet of the chassis.

[0007] Optionally: a TCS preheater is also included, the output end of the filter is connected to the hot-stage channel of the TCS preheater, the hot-stage channel of the TCS preheater is connected to the hot-stage channel of the TCS vaporization system; the cold-stage channel of the TCS preheater is connected to the cold-stage channel of the TCS preheater, and the cold-stage channel of the TCS preheater is connected to the inlet of the chassis.

[0008] Optionally: it also includes a waste heat utilization system, an electrode power regulating water tank and a water pipe, the waste heat utilization system and the electrode power regulating water tank are connected to each other, one end of the water pipe is connected to the waste heat utilization system, and the other end of the water pipe is connected to the electrode power regulating water tank, and the water pipe flows through the chassis, and the electrode power regulating water tank is used to regulate the pressure of the return water after being utilized by the waste heat utilization system.

[0009] Optionally: it also includes a medium-temperature water tank, the output end of which is arranged toward the chassis, and the medium-temperature water tank is used to recover the medium-temperature return water flowing through the chassis.

[0010] Optionally: the medium-temperature water tank is used to produce 0.2MPa water vapor using the medium-temperature return water.

[0011] Optionally: a high-temperature water tank is also included, the output end of the high-temperature water tank is arranged toward the bell jar, and the high-temperature water tank is used to recover high-temperature return water flowing through the bell jar.

[0012] Optionally: the high-temperature water tank is used to produce 0.4MPa water vapor using high-temperature return water.

[0013] Optionally: an ultra-high temperature water flash tank is also included, and the output end of the high temperature water tank is connected to the ultra-high temperature water flash tank.

[0014] Optionally: it also includes a tail gas heat exchanger, the tail gas of the reduction furnace enters the filter after passing through the hot channel of the tail gas heat exchanger, and the ultra-high temperature water flash tank is connected to the cold channel of the tail gas heat exchanger.

[0015] Optionally: the ultra-high temperature water flash tank is used to produce 1.0 MPa water vapor.

[0016] Compared with the prior art, the beneficial effects achieved by the utility model are:

[0017] The utility model discloses a system for efficiently utilizing waste heat from a reduction furnace, which includes a filter, a TCS vaporization system, an H2 heater, and a TCS preheater. The outlet on the chassis is connected to the hot passage of the filter, the hot passages of the filter, the TCS vaporization system, the H2 heater, and the TCS preheater are connected in sequence, the cold passages of the TCS preheater and the TCS vaporization system are connected in sequence and then connected to the inlet on the chassis, and the cold passage of the H2 heater is also connected to the inlet on the chassis.

[0018] The reduction furnace waste heat efficient utilization system disclosed in the utility model can utilize the reduction furnace tail gas multiple times. On the one hand, the preheated SiHCl3 has a higher temperature when entering the TCS vaporization system. At this time, the tail gas just discharged from the reduction furnace also has a higher temperature. Using the high-temperature tail gas to vaporize the preheated TCS can reduce heat loss. The tail gas temperature passing through the TCS vaporization system is slightly reduced. When passing through the TCS preheater, the SiHCl3 with a lower temperature is preheated. Since the temperature difference between the tail gas and SiHCl3 at this time is not too large, SiHCl3 can be more fully absorbed by the temperature in the tail gas. The present application can heat SiHCl3 multiple times through the multiple utilization of tail gas heat. On the other hand, the temperature difference between the tail gas and SiHCl3 in each link is controlled within a certain range, and when the tail gas passes through the TCS preheater, it has a lower temperature, which also makes the tail gas have a lower temperature when it is discharged, which can effectively reduce heat waste, thereby effectively improving the utilization rate of the reduction furnace waste heat. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of a system for efficiently utilizing waste heat from a reduction furnace disclosed in an embodiment of the utility model is shown;

[0020] Figure 2 A heat utilization schematic diagram of a reduction furnace waste heat efficient utilization system disclosed in an embodiment of the utility model is shown. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below through specific implementation examples in conjunction with the accompanying drawings. Example

[0022] The existing waste heat utilization process usually leads the tail gas from the reduction furnace to directly preheat the TCS in the TCS preheater. At this time, due to the large temperature difference between the tail gas and TCS, even if TCS can absorb more heat at this time, it is impossible to avoid the tail gas still having a high temperature when it is discharged, and this part of the heat will be wasted.

[0023] See also Figure 1 and Figure 2The embodiment of the utility model discloses a system for efficiently utilizing waste heat from a reduction furnace, which includes a filter, a TCS vaporization system, an H2 heater, and a TCS preheater. The outlet on the chassis is connected to the hot passage of the filter, the hot passages of the filter, the TCS vaporization system, the H2 heater, and the TCS preheater are connected in sequence, the cold passages of the TCS preheater and the TCS vaporization system are connected in sequence and then connected to the inlet on the chassis, and the cold passage of the H2 heater is also connected to the inlet on the chassis.

[0024] The high-efficiency utilization system of the waste heat of the reduction furnace disclosed in this embodiment can utilize the tail gas of the reduction furnace multiple times. On the one hand, the preheated SiHCl3 has a high temperature when entering the TCS vaporization system. At this time, the tail gas just discharged from the reduction furnace also has a high temperature. Using the high-temperature tail gas to vaporize the preheated TCS can reduce heat loss. The tail gas temperature passing through the TCS vaporization system is slightly reduced. When passing through the TCS preheater, it preheats the SiHCl3 with a lower temperature. Since the temperature difference between the tail gas and SiHCl3 at this time is not too large, SiHCl3 can absorb the temperature in the tail gas more fully. This application can heat SiHCl3 multiple times through the multiple utilization of the tail gas heat. On the other hand, the temperature difference between the tail gas and SiHCl3 in each link is controlled within a certain range, and when the tail gas passes through the TCS preheater, it has a lower temperature, which also makes the tail gas have a lower temperature when it is discharged, which can effectively reduce heat waste, thereby effectively improving the utilization rate of the waste heat of the reduction furnace.

[0025] The existing reduction furnace generally includes a bell cover, a chassis and electrodes. The bell cover is connected to the chassis, the electrodes are installed on the chassis, and an inlet and an outlet are provided on the chassis. The inlet is used for H2 and SiHCl3 to enter the reduction furnace, and the outlet is used for exhaust gas to be discharged.

[0026] The system for efficiently utilizing waste heat from the reduction furnace includes a filter for recovering waste heat from the tail gas of the reduction furnace, a TCS preheater, a TCS vaporization system, an H2 heater, and a TCS preheater. The input end of the filter is connected to the outlet of the chassis, and the output end of the filter is connected to the hot passage of the TCS preheater. The hot passage of the TCS preheater is connected to the hot passage of the TCS vaporization system, the hot passage of the TCS vaporization system is connected to the hot passage of the H2 heater, and the hot passage of the H2 heater is connected to the hot passage of the TCS preheater. The cold passage of the H2 heater is connected to the inlet of the chassis; the cold passage of the TCS preheater is connected to the cold passage of the TCS vaporization system, the cold passage of the TCS vaporization system is connected to the cold passage of the TCS preheater, and the cold passage of the TCS preheater is connected to the inlet of the chassis. Since the tail gas of the reduction furnace may carry silicon powder, the filter can be set to remove the silicon powder carried in the tail gas to avoid deposition and blockage in the subsequent pipelines.

[0027] The reduction furnace waste heat efficient utilization system disclosed in this embodiment also includes a high-temperature water tank for recycling the heat of the bell jar. The output end of the high-temperature water tank is arranged toward the bell jar, and the high-temperature water tank is used to recover the high-temperature return water flowing through the bell jar. The high-temperature water tank can use the high-temperature return water to produce 0.4MPa water vapor to provide heat for other devices in the plant area or for other uses, and the water with reduced temperature can cool the bell jar again.

[0028] The efficient utilization system of waste heat of the reduction furnace disclosed in this embodiment also includes a waste heat utilization system, an electrode power adjustment water tank, a water pipe and a medium-temperature water tank for recycling the heat of the chassis. The waste heat utilization system and the electrode power adjustment water tank are interconnected, one end of the water pipe is connected to the waste heat utilization system, the other end of the water pipe is connected to the electrode power adjustment water tank, and the water pipe flows through the chassis. The waste heat utilization system takes out the heat of the reduction furnace chassis electrode through circulating water, and the heat is utilized through the waste heat system. The waste heat utilization system includes waste heat utilization such as heating in the plant system. The electrode power adjustment water tank regulates the pressure of the return water after utilization by the waste heat utilization system, and cools down the chassis electrode of the reduction furnace. The output end of the medium-temperature water tank is arranged toward the chassis, and the medium-temperature water tank is used to recover the medium-temperature return water flowing through the chassis. The medium-temperature water tank can use the medium-temperature return water to produce 0.2MPa water vapor to provide heat for other devices in the plant or for other uses, and the water with reduced temperature can cool down the chassis again.

[0029] The reduction furnace waste heat efficient utilization system disclosed in this embodiment also includes an ultra-high temperature water flash tank and an exhaust gas heat exchanger for further utilizing the heat. The exhaust gas of the reduction furnace enters the filter after passing through the hot channel of the exhaust gas heat exchanger. The output end of the high temperature water tank is connected to the ultra-high temperature water flash tank, and the ultra-high temperature water flash tank is connected to the cold channel of the exhaust gas heat exchanger. The water flowing out of the high temperature water tank first enters the ultra-high temperature water flash tank, and then enters the cold channel of the exhaust gas heat exchanger to absorb the height of the reduction furnace exhaust gas, so that the 600°C reduction furnace exhaust gas is reduced to 200°C. The ultra-high temperature with increased temperature is recovered back to the ultra-high temperature water flash tank and can be used to produce 1.0MPa water vapor to provide heat for other devices in the plant or for other uses.

[0030] The reduction furnace waste heat efficient utilization system disclosed in this embodiment mainly utilizes the heat of the reduction furnace in three parts: the first part utilizes the heat of the bell jar during the production process; the second part utilizes the heat of the chassis during the production process; and the third part utilizes the waste heat of the tail gas after the reaction. Through the efficient utilization process of the original furnace waste heat, it is possible to reduce energy consumption, reduce carbon emissions, achieve energy conservation and emission reduction, and effectively improve the utilization rate of waste heat compared with the existing technology.

[0031] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A system for efficiently utilizing waste heat from a reduction furnace, for reusing waste heat from a reduction furnace, wherein the reduction furnace comprises a bell jar, a chassis and an electrode, wherein the bell jar is connected to the chassis, the electrode is mounted on the chassis, and an inlet and an outlet are provided on the chassis, wherein: The system includes a filter, a TCS vaporization system, an H2 heater and a TCS preheater, wherein the input end of the filter is communicated with the outlet of the chassis, the output end of the filter is communicated with a hot-range channel of the TCS vaporization system, the hot-range channel of the TCS vaporization system is communicated with the hot-range channel of the H2 heater, the hot-range channel of the H2 heater is communicated with the hot-range channel of the TCS preheater, the cold-range channel of the H2 heater is communicated with the inlet of the chassis, the cold-range channel of the TCS preheater is communicated with the cold-range channel of the TCS vaporization system, and the cold-range channel of the TCS vaporization system is communicated with the inlet of the chassis.

2. The system for efficiently utilizing waste heat from a reduction furnace according to claim 1, characterized in that: It also includes a TCS preheater, the output end of the filter is connected to the hot path channel of the TCS preheater, the hot path channel of the TCS preheater is connected to the hot path channel of the TCS vaporization system; the cold path channel of the TCS preheater is connected to the cold path channel of the TCS preheater, and the cold path channel of the TCS preheater is connected to the inlet of the chassis.

3. The system for efficiently utilizing waste heat from a reduction furnace according to claim 1, characterized in that: It also includes a waste heat utilization system, an electrode power regulating water tank and a water pipe. The waste heat utilization system and the electrode power regulating water tank are connected to each other. One end of the water pipe is connected to the waste heat utilization system, and the other end of the water pipe is connected to the electrode power regulating water tank. The water pipe flows through the chassis. The electrode power regulating water tank is used to regulate the pressure of the return water after being utilized by the waste heat utilization system.

4. The system for efficiently utilizing waste heat from a reduction furnace according to claim 1, characterized in that: It also includes a medium-temperature water tank, the output end of which is arranged toward the chassis, and the medium-temperature water tank is used to recover the medium-temperature return water flowing through the chassis.

5. The system for efficiently utilizing waste heat from a reduction furnace according to claim 4, characterized in that: The medium-temperature water tank is used to produce 0.2 MPa water vapor using the medium-temperature return water.

6. The system for efficiently utilizing waste heat from a reduction furnace according to claim 1, characterized in that: It also includes a high-temperature water tank, the output end of which is arranged toward the bell jar, and the high-temperature water tank is used to recover high-temperature return water flowing through the bell jar.

7. The system for efficiently utilizing waste heat from a reduction furnace according to claim 6, characterized in that: The high temperature water tank is used to produce 0.4 MPa water vapor using high temperature return water.

8. The system for efficiently utilizing waste heat from a reduction furnace according to claim 6, characterized in that: It also includes an ultra-high temperature water flash tank, and the output end of the high temperature water tank is connected to the ultra-high temperature water flash tank.

9. The system for efficiently utilizing waste heat from a reduction furnace according to claim 8, characterized in that: It also includes a tail gas heat exchanger, and the tail gas of the reduction furnace enters the filter after passing through the hot channel of the tail gas heat exchanger, and the ultra-high temperature water flash tank is connected to the cold channel of the tail gas heat exchanger.

10. The system for efficiently utilizing waste heat from a reduction furnace according to claim 9, characterized in that: The ultra-high temperature water flash tank is used to produce 1.0 MPa water vapor.

Images