Polycrystalline silicon production waste heat utilization system
By introducing a refrigeration cycle system consisting of an ammonia generator, an ammonia condenser, and a liquid ammonia evaporator into polysilicon production, and utilizing surplus heat energy to condense liquid ammonia, the problem of resource waste caused by steam discharge in polysilicon production is solved, energy utilization is improved, and production costs are reduced.
Patent Information
- Application Number
- CN202520187005.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-06
- Publication Date
- 2026-01-30
- Estimated Expiration
- 2035-02-06
AI Technical Summary
In existing technologies, excess steam generated during polysilicon production is directly discharged, resulting in a waste of heat energy and water resources.
A refrigeration cycle system consisting of an ammonia generator, an ammonia condenser, a liquid ammonia evaporator, and an ammonia absorber is used to precipitate ammonia gas from an ammonia mixture using surplus heat energy. The ammonia gas is then condensed into liquid ammonia and used in the condensation process of polycrystalline silicon production, replacing electrically driven refrigeration equipment.
It enables the effective utilization of surplus heat energy in the polysilicon production process, reduces the discharge of low-pressure steam, improves energy efficiency, reduces or replaces the power load of electrically driven refrigeration equipment, and reduces resource waste.
Smart Images
Figure CN223856256U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of polysilicon production, and in particular to a polysilicon production waste heat utilization system. BACKGROUND
[0002] At present, the high-purity polysilicon reduction process generally adopts a vapor deposition method to produce a silicon core, which will generate a large amount of steam. In addition to the normal consumption of the steam for polysilicon production and daily operation, there will also be a surplus.
[0003] Since the steam cannot continue to be supplied to the reduction section for cooling use without being cooled by heat exchange and then being condensed, the prior art generally cools part of the steam by using cooling water. However, when there is too much steam, the surplus steam can only be directly discharged externally, which wastes a large amount of heat and water. CONTENT OF THE UTILITY MODEL
[0004] The present application provides a polysilicon production waste heat utilization system to solve the problem of resource waste caused by directly discharging the surplus steam in the polysilicon production in the prior art.
[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical solution:
[0006] The present application provides a polysilicon production waste heat utilization system, comprising: an ammonia generator containing an ammonia mixed solution and configured to allow surplus heat energy generated in the polysilicon production to enter, so as to make the ammonia mixed solution precipitate ammonia gas by using the surplus heat energy; an ammonia gas condenser, the inlet end of the ammonia gas condenser being in communication with the outlet end of the ammonia generator; a liquid ammonia evaporator, the inlet end of the liquid ammonia evaporator being in communication with the outlet end of the ammonia gas condenser, the liquid ammonia evaporator being used to provide a low-temperature condensing environment for a material to be separated in the polysilicon production; and an ammonia gas absorber connected between the outlet end of the liquid ammonia evaporator and the inlet end of the ammonia generator.
[0007] As an optional embodiment, the system further comprises an ammonia heat exchanger connected between the outlet end of the ammonia gas condenser and the inlet end of the liquid ammonia evaporator.
[0008] As an optional embodiment, a throttle valve is connected between the outlet end of the ammonia heat exchanger and the inlet end of the liquid ammonia evaporator.
[0009] As an optional embodiment, the ammonia heat exchanger is further connected between the outlet end of the liquid ammonia evaporator and the inlet end of the ammonia gas absorber.
[0010] As an optional embodiment, a booster pump is connected between the outlet end of the ammonia gas absorber and the inlet end of the ammonia generator.
[0011] As an optional implementation, the system further comprises a pre-cooler connected between the outlet end of the ammonia generator and the inlet end of the ammonia absorber, for cooling the working solution separated from the ammonia mixed solution.
[0012] As an optional implementation, the liquid ammonia evaporator is provided with a gaseous freon input end and a liquid freon output end; the liquid freon is used to condense the chlorosilane mixed gas in the polysilicon production into liquid.
[0013] As an optional implementation, the system further comprises a freon buffer, and the inlet end of the freon buffer is connected to the liquid freon output end.
[0014] As an optional implementation, the system further comprises a condensate collector, and the inlet end of the condensate collector is connected to the outlet end of the ammonia generator.
[0015] As an optional implementation, the excess heat energy comprises steam of 0.4Mpa-1.0Mpa.
[0016] The polysilicon production excess heat utilization system provided by the application comprises an ammonia generator, an ammonia condenser, a liquid ammonia evaporator, and an ammonia absorber. The inlet end of the ammonia condenser is connected to the outlet end of the ammonia generator, the inlet end of the liquid ammonia evaporator is connected to the outlet end of the ammonia condenser, and the ammonia absorber is connected between the outlet end of the liquid ammonia evaporator and the inlet end of the ammonia generator.
[0017] The ammonia generator contains an ammonia mixed solution and is configured to be supplied with excess heat energy generated in the polysilicon production. Under the action of the excess heat energy, ammonia in the ammonia mixed solution is separated out in the form of gas and enters the ammonia condenser. In the ammonia condenser, the ammonia gas flows in and is condensed into liquid ammonia, which is introduced into the liquid ammonia evaporator to condense the refrigerant. Thus, a low-temperature condensing environment can be provided for the material to be separated in the polysilicon production.
[0018] Through the above arrangement, by using the characteristics that the working solution can separate out the gas phase refrigerant of the low-boiling-point component under certain conditions and can absorb the gas phase refrigerant of the low-boiling-point component under another condition, the refrigeration cycle can be completed, the gas phase refrigerant can be condensed into liquid refrigerant, the effective utilization of the excess heat energy generated in the polysilicon production process can be realized, the low-pressure steam discharge can be reduced, and the energy utilization rate can be improved. Moreover, the low-economical-steam heat can be used to replace the electrically-driven refrigeration equipment in the polysilicon production system, so as to achieve the effect of reducing or completely replacing the power load of the original electrically-driven refrigeration equipment. BRIEF DESCRIPTION OF DRAWINGS
[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.
[0020] Figure 1 A structural schematic diagram of a polysilicon production waste heat utilization system provided by an embodiment of the present application is shown in the figure.
[0021] Figure 2 A structural schematic diagram of another polysilicon production waste heat utilization system provided by an embodiment of the present application is shown in the figure.
[0022] Figure 3 A structural schematic diagram of still another polysilicon production waste heat utilization system provided by an embodiment of the present application is shown in the figure.
[0023] Figure 4 A structural schematic diagram of yet another polysilicon production waste heat utilization system provided by an embodiment of the present application is shown in the figure.
[0024] Explanation of reference signs:
[0025] 100-ammonia generator; 200-ammonia condenser; 300-liquid ammonia evaporator; 400-ammonia absorber; 500-ammonia heat exchanger; 600-boosting pump; 700-precooler; 800- condensate collector; 900-fluorin buffer. DETAILED DESCRIPTION
[0026] Polysilicon is an upstream raw material for the photovoltaic and semiconductor industries, and is mainly purified through a series of chemical treatments on industrial silicon powder, so as to obtain solar-grade polysilicon and electronic-grade crystalline silicon that can be applied to the solar and electronic industries.
[0027] At present, the high-purity polysilicon reduction process generally adopts a vapor deposition method to produce silicon cores. That is, under high-temperature conditions, silane or chlorosilane in a reduction furnace is decomposed or reduced to release silicon atoms, and the silicon atoms are deposited on the surface of a substrate to form a high-purity polysilicon layer. Since the reaction temperature in the reduction furnace is usually between 1100°C and 1200°C, cooling water must be used to cool the reduction furnace during production to ensure that the equipment temperature does not become too high to cause an accident.
[0028] To ensure production safety, a cooling water jacket is usually clamped around the outside of the furnace cylinder of the reduction furnace, and cooling water is injected into the cooling water jacket to absorb and carry away the excess heat generated by the furnace cylinder. After absorbing the heat of the furnace cylinder, the cooling water forms high-temperature and high-pressure cooling water return water. The cooling water return water is subjected to pressure reduction flash evaporation to reduce its temperature and pressure, so that it can be pumped back into the cooling water jacket to realize cyclic cooling. At the same time, the low-temperature and low-pressure steam generated during the flash evaporation also absorbs the heat in the cooling water return water, thereby having a certain amount of waste heat. However, due to the low energy density and high water content of this part of steam, it cannot fully meet the high-temperature or high-pressure requirements of industrial processes. In the prior art, it is usually directly discharged, thereby possibly causing waste of heat energy and water.
[0029] At the same time, in the polysilicon production process, the chlorosilane mixed gas generated in the production needs to be separated through a condensation section. In the prior art, an electrically driven screw refrigeration compressor main machine and auxiliary equipment are usually needed to condense the refrigerant.
[0030] Therefore, the present application provides a polysilicon production waste heat utilization system, which comprises an ammonia generator, an ammonia condenser, a liquid ammonia evaporator, and an ammonia absorber. The inlet end of the ammonia condenser is in communication with the outlet end of the ammonia generator, the inlet end of the liquid ammonia evaporator is in communication with the outlet end of the ammonia condenser, and the ammonia absorber is connected between the outlet end of the liquid ammonia evaporator and the inlet end of the ammonia generator.
[0031] The ammonia generator contains an ammonia mixed solution and is configured to allow the excess heat energy generated in the polysilicon production to enter. Under the action of the excess heat energy, ammonia in the ammonia mixed solution is separated out in the form of gas and enters the ammonia condenser. In the ammonia condenser, the flowing ammonia gas is condensed into liquid ammonia and is introduced into the liquid ammonia evaporator to condense the refrigerant, thereby providing a low-temperature condensation environment for the separated material in the polysilicon production.
[0032] Through the above arrangement, the working fluid solution can separate out the gas phase refrigerant of the low-boiling-point component under certain conditions, and can also absorb the gas phase refrigerant of the low-boiling-point component under another condition. This feature can complete the refrigeration cycle, condense the gas phase refrigerant into liquid refrigerant, realize the effective utilization of the excess heat energy generated in the polysilicon production process, reduce the discharge of low-pressure steam, and improve the energy utilization rate. Moreover, the excess low-economical steam heat can be used to replace the electrically driven refrigeration equipment in the polysilicon production system to achieve the effect of reducing or completely replacing the power load of the original electrically driven refrigeration equipment.
[0033] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall into the scope of protection of the present application. The embodiments described below and the features in the embodiments can be combined with each other without conflict.
[0034] Figure 1 A structural schematic diagram of a polysilicon production waste heat utilization system provided by the embodiments of the present application is shown in FIG. 1. As shown in FIG. 1, the present application provides a polysilicon production waste heat utilization system, which comprises an ammonia generator 100, an ammonia condenser 200, a liquid ammonia evaporator 300 and an ammonia absorber 400. Figure 1
[0035] The inlet end of the ammonia condenser 200 is in communication with the outlet end of the ammonia generator 100, the inlet end of the liquid ammonia evaporator 300 is in communication with the outlet end of the ammonia condenser 200, and the ammonia absorber 400 is connected between the outlet end of the liquid ammonia evaporator 300 and the inlet end of the ammonia generator 100.
[0036] The ammonia generator 100 contains an ammonia mixed solution and can be supplied with surplus heat energy generated in polysilicon production. The ammonia mixed solution in the ammonia generator 100 is heated by taking the surplus heat energy as a heat source, and the dissolved ammonia can be evaporated and separated out in the form of gas to flow from the outlet end of the ammonia generator 100 to the inlet end of the ammonia condenser 200.
[0037] The evaporated ammonia gas is condensed into liquid ammonia in the ammonia condenser 200. Exemplarily, the heat exchange medium in the ammonia condenser 200 can be circulating water. The liquid ammonia can flow from the outlet end of the ammonia condenser 200 to the inlet end of the liquid ammonia evaporator 300 to condense the refrigerant in the liquid ammonia evaporator 300. Thus, a low-temperature condensing environment can be provided for the material to be separated in polysilicon production. In this process, the liquid ammonia can be expanded by throttling to reduce the pressure and the boiling point, and condense the refrigerant into a liquid state by vaporization heat absorption.
[0038] It can be understood that the surplus heat energy generated in polysilicon production can include low-temperature and low-pressure steam. The ammonia mixed solution is a mixed solution of ammonia and a working solution. The working solution can be water or other liquid that can dissolve ammonia, which is not limited here.
[0039] The ammonia gas flowing out of the outlet end of the liquid ammonia evaporator 300 can flow to the inlet end of the ammonia gas absorber 400. The pure working solution separated by the ammonia gas generator 100 is recovered in the ammonia gas absorber 400, so that the ammonia gas can be dissolved again to obtain an ammonia mixed solution. The ammonia mixed solution reflows into the inlet end of the ammonia gas generator 100 through the outlet end of the ammonia gas absorber 400, so that the circulation can be realized.
[0040] In this way, the surplus heat energy generated in the polysilicon production process can be effectively utilized, the low-pressure steam discharge can be reduced, the heat can be converted into the required cold, and the energy can be fully utilized. Moreover, the surplus low-economical steam heat can be consumed to replace the electrically driven refrigeration equipment in the polysilicon production system, so that the power load of the original electrically driven refrigeration equipment can be reduced or completely replaced, thereby further reducing the production cost.
[0041] For example, the surplus heat energy generated in the polysilicon production process can include steam of 0.4 MPa-1.0 MPa.
[0042] Figure 2 Another structure schematic diagram of a polysilicon production waste heat utilization system provided by an embodiment of the present application is provided. Referring to Figure 2 As shown in the figure, the polysilicon production waste heat utilization system can further include an ammonia heat exchanger 500. The ammonia heat exchanger 500 can be connected between the outlet end of the ammonia gas condenser 200 and the inlet end of the liquid ammonia evaporator 300.
[0043] By arranging the ammonia heat exchanger 500, the liquid ammonia flowing out of the outlet end of the ammonia gas condenser 200 can be further cooled, so that the temperature of the liquid ammonia is lower, and the condensation effect of the refrigerant after entering the liquid ammonia evaporator 300 is better. It should be noted that the heat exchange medium in the ammonia heat exchanger 500 can only cool the liquid ammonia therein, and is not limited herein.
[0044] As an implementation manner, a throttle valve is connected between the outlet end of the ammonia heat exchanger 500 and the inlet end of the liquid ammonia evaporator 300. The throttle valve can adjust the pressure and flow of the ammonia gas flowing into the liquid ammonia evaporator 300.
[0045] Since the flow resistance can be increased by narrowing the channel of fluid flow, when the liquid ammonia passes through the throttle valve, the channel is narrowed, the flow rate of the fluid is increased, and the pressure is decreased. After the pressure is reduced, the temperature of the liquid ammonia is also reduced. Further, the cooling effect of the liquid ammonia evaporator 300 can be improved.
[0046] Figure 3 Another structure schematic diagram of a polysilicon production waste heat utilization system provided by an embodiment of the present application is provided. Referring to Figure 3As shown, the ammonia heat exchanger 500 can also be connected between the outlet end of the liquid ammonia evaporator 300 and the inlet end of the ammonia gas absorber 400. Specifically, the ammonia heat exchanger 500 is provided with a liquid ammonia inlet end and an ammonia gas inlet end. The liquid ammonia inlet end of the ammonia heat exchanger 500 is in communication with the outlet end of the ammonia gas condenser 200. The ammonia gas inlet end of the ammonia heat exchanger 500 is in communication with the outlet end of the liquid ammonia evaporator 300.
[0047] It can be understood that, since the boiling point of ammonia will increase with the increase of pressure, when the ammonia gas condensed in the ammonia gas condenser 200 has a high pressure, the liquid ammonia treated by the ammonia gas condenser 200 also has a high temperature.
[0048] For example, when the ammonia mixed solution in the ammonia gas generator 100 is in a high pressure state, its boiling point will also increase accordingly. At this time, the dissolved ammonia in the ammonia gas generator 100 will evaporate at a temperature higher than the normal boiling point, obtaining high-pressure ammonia gas. Since the ammonia gas has a high pressure, the temperature of the liquid ammonia condensed by the ammonia gas condenser 200 will also be higher than the temperature of the liquid ammonia under standard atmospheric pressure.
[0049] And the ammonia gas treated by the liquid ammonia evaporator 300 is in a low-temperature and low-pressure state under the action of throttling expansion. At this time, the temperature of the ammonia gas flowing out of the outlet end of the liquid ammonia evaporator 300 is lower than the temperature of the liquid ammonia flowing out of the outlet end of the ammonia gas condenser 200. Thus, the cooling effect of the liquid ammonia can be achieved.
[0050] In this way, the low-temperature and low-pressure ammonia gas flowing out of the outlet end of the liquid ammonia evaporator 300 can be used to heat exchange and cool the high-pressure liquid ammonia flowing into the ammonia heat exchanger 500. Thus, the further cooling of the liquid ammonia is achieved, the economic performance of the overall system is improved, and the refrigeration effect of the refrigerant in the subsequent evaporator is also improved.
[0051] Figure 4 Another structure schematic diagram of a polysilicon production waste heat utilization system provided by the embodiment of the present application is provided. Referring to Figure 4 As shown, the polysilicon production waste heat utilization system further includes a pre-cooler 700. The pre-cooler 700 is connected between the outlet end of the ammonia gas generator 100 and the inlet end of the ammonia gas absorber 400, and can be used to cool the working solution separated from the ammonia mixed solution.
[0052] Specifically, the working solution separated from the ammonia can enter the inlet end of the pre-cooler 700 through the bottom pipeline outlet end of the ammonia gas generator 100, and is cooled in the pre-cooler 700, so that the working solution flowing out has a lower temperature. Based on the low-temperature condition, the ammonia gas has a higher solubility. By pre-cooling the recovered working solution, the ammonia gas dissolution effect in the ammonia gas absorber 400 can be enhanced.
[0053] In some embodiments, a booster pump 600 is connected between the outlet end of the ammonia absorber 400 and the inlet end of the ammonia generator 100. The low-temperature and low-pressure ammonia gas flowing out of the outlet end of the liquid ammonia evaporator 300 is cooled by the liquid ammonia in the ammonia heat exchanger 500, and then flows out of the ammonia heat exchanger 500 and enters the ammonia absorber 400 through the inlet end of the ammonia absorber 400, and is dissolved in the working fluid solution in the ammonia absorber 400 to obtain a low-pressure and low-temperature ammonia mixed solution.
[0054] At this time, by setting the booster pump 600 between the ammonia absorber 400 and the ammonia generator 100, the low-temperature and low-pressure ammonia mixed solution can be converted into a high-pressure solution, which is convenient for the subsequent condensation treatment of high-pressure ammonia in the condenser.
[0055] As an embodiment, the liquid ammonia evaporator 300 is provided with a gaseous freon input end and a liquid freon output end. The liquid freon can be used as a refrigerant to condense the chlorosilane mixed gas in the polysilicon production into liquid. In the liquid ammonia evaporator 300, the low-temperature and low-pressure liquid ammonia is vaporized to absorb heat in the gaseous freon, so that the gaseous freon is condensed into liquid freon, which can be used as a refrigerant to provide a low-temperature condensation environment for the condensation process in the polysilicon production process.
[0056] It can be understood that the liquid ammonia evaporator 300 can be in the form of a dry evaporator, a shell-and-tube evaporator, a finned tube evaporator, a flooded evaporator, a semi-liquid evaporator, etc., which is not limited herein.
[0057] The freon can refer to (chlorofluorocarbons), such as R-11 (trifluoromonochloromethane, ), R-12 (difluorodichloromethane, ), R-113 (trifluorotrichloroethane, ), and can also be (hydrochlorofluorocarbons), such as R-22 (fluorochlorodihydro methane, ), R-123 (difluorotrichloroethane, ), or (hydrofluorocarbons), (hydrofluoroolefins), etc., which are not specifically limited herein.
[0058] As an optional embodiment, the polysilicon production waste heat utilization system further comprises a freon buffer 900, and the inlet end of the freon buffer 900 is connected in communication with the liquid freon output end. The liquid freon cooled by the liquid ammonia evaporator 300 can be stored in the freon buffer 900.
[0059] By setting the freon buffer 900, the condensed liquid freon refrigerant can be stored. When the refrigerant is needed in the condensation section, it can be pumped and delivered to the corresponding equipment.
[0060] As an implementation, the polysilicon production waste heat utilization system further comprises a condensate collector 800. The inlet end of the condensate collector 800 is connected to the outlet end of the ammonia generator 100. Exemplarily, the condensate collector 800 can be a condensate tank. By collecting the condensate, the condensate can be sent to other sections, such as a condensing section, for further recycling.
[0061] Specifically, the inlet end of the ammonia generator 100 can comprise a steam inlet end and an ammonia mixture solution inlet end. The surplus heat energy can enter the ammonia generator 100 through the steam inlet end. The recovered ammonia mixture solution can enter the ammonia generator 100 through the ammonia mixture solution inlet end after being pressurized by the booster pump 600. The outlet end of the ammonia generator 100 can comprise an ammonia gas outlet end, a working fluid solution outlet end, and a condensate outlet end. The inlet end of the condensate collector 800 is connected to the condensate outlet end of the ammonia generator 100. The working fluid solution outlet end of the ammonia generator 100 is connected to the pre-cooler 700. The ammonia gas outlet end of the ammonia generator 100 is connected to the inlet end of the ammonia gas condenser 200.
[0062] The process flow of the polysilicon production waste heat utilization system provided by the embodiments of the present application is further described below. The polysilicon production waste heat utilization system mainly involves ammonia circulation and working fluid circulation.
[0063] Ammonia circulation: The ammonia mixture solution is heated in the ammonia generator 100 by using a heat source (0.4-1.0 MPa water vapor) to evaporate ammonia therein as a refrigerant in the system and condense into liquid ammonia (the condensing process is performed in the ammonia gas condenser 200 by circulating water heat exchange). The liquid ammonia is heat-exchanged in the ammonia heat exchanger 500 (liquid ammonia and ammonia gas heat exchange) and sent to the liquid ammonia evaporator 300 (liquid ammonia is vaporized by reducing the pressure through throttling expansion to reduce the boiling point and condense Freon into liquid), and the Freon solution is cooled and sent out of the boundary region (to cool the process material). The vaporized ammonia gas is heat-exchanged in the ammonia heat exchanger 500 (ammonia gas and liquid ammonia heat exchange), enters the ammonia gas absorber 400 (working fluid solution absorbs ammonia gas), is pressurized by a pump (to provide high pressure for the subsequent condensed liquid ammonia) and sent to the ammonia generator 100 to complete the circulation.
[0064] Working fluid cycle: the ammonia mixed solution is heated in the ammonia generator 100 by using the heat source (0.4-1.0 MPa water vapor) to separate the pure working fluid solution after the ammonia and the working fluid (generator bottom pipeline), and the pure working fluid solution is cooled by the pre-cooler 700 (higher absorbance under low temperature conditions) to absorb ammonia gas, and at this time the ammonia gas absorber 400 is the ammonia mixed solution. The ammonia mixed solution is pumped to the ammonia generator 100 to complete the cycle. In this process, the steam will be cooled to water condensate in the ammonia generator 100, which can be collected by the condensate tank (0.4-1.0 MPa water vapor) in the ammonia generator 100. The water solution condensed in the ammonia generator 100 is sent to other sections for use.
[0065] It should be noted that the terms "one embodiment", "an embodiment", "certain embodiments", "some embodiments", etc. in the specification are intended to indicate that the described embodiment can include a particular feature, structure, or characteristic, but not necessarily every embodiment. In addition, such terms are not necessarily referring to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted within the knowledge of those skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
[0066] Generally, the terms should be understood, at least in part, to mean a singular number use or a plural number use, as appropriate to the context in which they are used. For example, depending on the context, the term "one or more" used in the description can be used to describe any feature, structure, or characteristic in the singular or can be used to describe combinations of features, structures, or characteristics, whether large or small, whether related or unrelated to each other. Similarly, terms such as "a" or "said" can be understood, at least in part, to convey a singular usage or to convey a plural usage, depending on the context in which they are used.
[0067] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.
Claims
1. A polysilicon production waste heat utilization system, characterized by, The application relates to a device for producing ammonia gas, comprising: an ammonia gas generator containing an ammonia mixed solution and configured to be connected to a surplus heat energy generated in polysilicon production, so as to utilize the surplus heat energy to make the ammonia mixed solution release ammonia gas; an ammonia gas condenser, the inlet end of which is communicated with the outlet end of the ammonia gas generator; a liquid ammonia evaporator, the inlet end of which is communicated with the outlet end of the ammonia gas condenser, and the liquid ammonia evaporator is used for providing a low-temperature condensing environment for a material to be separated in polysilicon production; an ammonia gas absorber connected between the outlet end of the liquid ammonia evaporator and the inlet end of the ammonia gas generator.
2. The polysilicon production waste heat utilization system according to claim 1, wherein Further comprising: an ammonia heat exchanger connected between the outlet end of the ammonia gas condenser and the inlet end of the liquid ammonia evaporator.
3. The polysilicon production waste heat utilization system according to claim 2, wherein A throttle valve is connected between the outlet end of the ammonia heat exchanger and the inlet end of the liquid ammonia evaporator.
4. The polysilicon production waste heat utilization system according to claim 2, wherein The ammonia heat exchanger is further connected between the outlet end of the liquid ammonia evaporator and the inlet end of the ammonia gas absorber.
5. The system for utilizing waste heat of polysilicon production according to any one of claims 1 to 4, characterized in that, A booster pump is connected between the outlet end of the ammonia gas absorber and the inlet end of the ammonia gas generator.
6. The system for utilizing waste heat of polysilicon production according to any one of claims 1 to 4, wherein Further comprising: a precooler connected between the outlet end of the ammonia gas generator and the inlet end of the ammonia gas absorber, and used for cooling a working solution separated from the ammonia mixed solution.
7. The system for utilizing waste heat of polysilicon production according to any one of claims 1 to 4, wherein The liquid ammonia evaporator is provided with a gaseous freon input end and a liquid freon output end. The liquid freon is used for condensing chlorosilane mixed gas in polysilicon production into liquid state.
8. The polysilicon production waste heat utilization system according to claim 7, wherein Further comprising a freon buffer, the inlet end of which is communicated with the liquid freon output end.
9. The system for utilizing waste heat of polysilicon production according to any one of claims 1 to 4, wherein Further comprising a condensate collector, the inlet end of which is communicated with the outlet end of the ammonia gas generator.
10. The system for utilizing waste heat of polysilicon production according to any one of claims 1 to 4, wherein The surplus heat energy comprises steam with a pressure of 0.4-1.0 MPa.