System for utilizing heat energy between materials in cold hydrogenation process

Abstract

A heat energy utilization system between materials in a cold hydrogenation process comprises a silicon tetrachloride preheater, a hydrogen preheater and a return tank, the silicon tetrachloride preheater is communicated with a silicon tetrachloride heat exchanger through a pipeline, and the silicon tetrachloride heat exchanger is communicated with a hydrogen heat exchanger through a pipeline. The silicon tetrachloride heat exchanger and the hydrogen heat exchanger are communicated with the return tank through pipelines; the hydrogen preheater is communicated with the hydrogen heat exchanger. According to the system, the silicon tetrachloride heat exchanger and the hydrogen heat exchanger are used for replacing an original low-pressure steam generator, original heat exchange between materials and hot water is replaced with heat exchange between the materials, then the risks of material leakage and system emergency shutdown caused by heat exchanger perforation are completely eradicated, the failure rate of equipment can be reduced, and the service life of the equipment can be prolonged.

Description

TECHNICAL FIELD

[0001] The utility model belongs to photovoltaic technical field, especially relate to a heat energy utilization system between materials in cold hydrogenation process. BACKGROUND

[0002] Cold hydrogenation is an important process link of producing trichlorosilane, and a large amount of energy is consumed to maintain certain temperature and pressure conditions in the reaction process, so as to promote the smooth progress of the reaction. For example, hydrogen and silicon tetrachloride raw materials need to be heated from low temperature to high temperature step by step before entering the vaporizer, and this process needs to consume a large amount of external energy, which increases the production cost. However, with the fluctuation of energy market and the increasing demand for energy, the cost of enterprises to obtain external energy (such as electricity, natural gas, etc.) gradually rises. For trichlorosilane production enterprises, energy cost accounts for a large proportion in the total cost, so reducing energy consumption and cost has become the focus of enterprises.

[0003] The perforation problem of the low-pressure steam generator and the crude distillation column reboiler in the cold hydrogenation section in normal production is attributed to the low-pressure steam generator. Since the steam required by the crude distillation column reboiler is generated by the low-pressure steam generator, after the low-pressure steam generator is perforated, the material gas meets hot water to form acid, thereby causing corrosion to the low-pressure steam pipeline and the reboiler, greatly shortening the service life of the equipment pipeline. SUMMARY

[0004] The technical problem to be solved by the utility model is to provide a heat energy utilization system between materials in cold hydrogenation process, which replaces the original low-pressure steam generator with a silicon tetrachloride heat exchanger and a hydrogen heat exchanger, replaces the original heat exchange between materials and hot water with heat exchange between materials, thereby eliminating the risk of material leakage and system emergency shutdown caused by heat exchanger perforation, reducing the failure rate of equipment, and prolonging the service life of equipment.

[0005] To solve the above technical problems, the technical scheme adopted by the utility model is:

[0006] A heat energy utilization system between materials in cold hydrogenation process, comprising a silicon tetrachloride preheater, a hydrogen preheater and a reflux tank, the silicon tetrachloride preheater is communicated with a silicon tetrachloride heat exchanger through a pipeline, the silicon tetrachloride heat exchanger is communicated with a hydrogen heat exchanger through a pipeline, and the silicon tetrachloride heat exchanger and the hydrogen heat exchanger are communicated with the reflux tank through a pipeline; the hydrogen preheater is communicated with the hydrogen heat exchanger.

[0007] The system further comprises a silicon tetrachloride feeding pump, which is communicated with the feeding port of the silicon tetrachloride preheater and the silicon tetrachloride heat exchanger through a pipeline respectively.

[0008] Preferably, the silicon tetrachloride feed pump is communicated with the feed port of the silicon tetrachloride preheater through a first pipeline, and the silicon tetrachloride feed pump is communicated with the feed port of the silicon tetrachloride heat exchanger through a second pipeline;

[0009] The first pipeline is provided with a first valve and a second valve, and the second pipeline is provided with a fourth valve;

[0010] The output end of the second valve is communicated with a third pipeline, the third pipeline is communicated with the feed port of the silicon tetrachloride heat exchanger, and the third pipeline is provided with a third valve.

[0011] The system further comprises a circulating hydrogen compressor, and the circulating hydrogen compressor is communicated with the feed ports of the hydrogen preheater and the hydrogen heat exchanger through pipelines.

[0012] Preferably, the circulating hydrogen compressor is communicated with the feed port of the hydrogen preheater through a fourth pipeline, and the circulating hydrogen compressor is communicated with the feed port of the hydrogen heat exchanger through a fifth pipeline;

[0013] The fourth pipeline is provided with a fifth valve and a sixth valve, and the fifth pipeline is provided with an eighth valve;

[0014] The output end of the sixth valve is communicated with a sixth pipeline, the sixth pipeline is communicated with the feed port of the hydrogen heat exchanger, and the sixth pipeline is provided with a seventh valve.

[0015] Preferably, the silicon tetrachloride heat exchanger and the hydrogen heat exchanger are used to simultaneously cool the material of the crude trichlorosilane separation tower, and the cooled material flows back to the reflux tank.

[0016] Preferably, the silicon tetrachloride preheater and the hydrogen preheater preheat the silicon tetrachloride, and then the silicon tetrachloride is introduced into the silicon tetrachloride vaporizer.

[0017] The utility model can achieve the following beneficial effects:

[0018] 1. The utility model cancels the low-pressure steam generator in the existing process, simultaneously introduces the silicon tetrachloride heat exchanger and hydrogen heat exchanger to utilize heat energy. The design purpose of the silicon tetrachloride heat exchanger is to exchange heat between the material gas at the top of the crude trichlorosilane separation tower and the raw material silicon tetrachloride to reduce the high-pressure steam consumption of the silicon tetrachloride preheater. The hydrogen heat exchanger exchanges heat between the material gas and the raw material hydrogen to reduce the high-pressure steam consumption of the circulating hydrogen heater.

[0019] 2. The silicon tetrachloride heat exchanger and the hydrogen heat exchanger replace the original low-pressure steam generator, replace the heat exchange between the original material and hot water with the heat exchange between materials, and further eliminate the risk of material leakage and system emergency shutdown caused by the perforation of the heat exchanger, can reduce the failure rate of equipment, prolong the service life of equipment.

[0020] 3. The heat exchange between materials makes the originally lost heat converted into usable energy, further reduces the steam consumption of the system, and realizes the full utilization of heat energy, playing a role in energy saving and consumption reduction. BRIEF DESCRIPTION OF DRAWINGS

[0021] The utility model will be further described below in combination with the drawings and examples:

[0022] Figure 1 The utility model is a system diagram.

[0023] In the figure: silicon tetrachloride preheater 1, hydrogen preheater 2, reflux tank 3, silicon tetrachloride heat exchanger 4 communication, hydrogen heat exchanger 5;

[0024] 1# indicates the first valve; 2# indicates the first valve; 3# indicates the first valve; 4# indicates the first valve; 5# indicates the first valve; 6# indicates the first valve; 7# indicates the first valve; 8# indicates the first valve. DETAILED DESCRIPTION

[0025] The preferred scheme is as shown in Figure 1 A heat energy utilization system between materials in cold hydrogenation process, comprising:

[0026] 1) Connection mode: remove the original low-pressure steam generator, and add a shell-and-tube silicon tetrachloride (STC) heat exchanger and a shell-and-tube hydrogen (H2) heat exchanger. The shell inlet of the STC heat exchanger is connected to the crude trichlorosilane separation tower, and the shell outlet is connected to the H2 heat exchanger and the crude trichlorosilane separation reflux tank 3; the tube inlet of the STC heat exchanger is connected to the STC feed pump, and the tube outlet is connected to the STC preheater. The shell inlet of the H2 heat exchanger is connected to the STC heat exchanger, and the shell outlet is connected to the crude trichlorosilane separation reflux tank 3 and the primary cooler; the tube inlet of the H2 heat exchanger is connected to the H2 preheater, and the tube outlet is connected to the STC gasifier.

[0027] 2) Heat exchange process: heat exchange between high-temperature material gas from the top of the crude trichlorosilane separation tower and low-temperature silicon tetrachloride raw material from the STC feed pump to increase the temperature of the silicon tetrachloride raw material, thereby reducing the high-pressure steam consumption of the silicon tetrachloride preheater 1. Similarly, the hydrogen heat exchanger 5 exchanges heat between the material gas and the raw material hydrogen to reduce the high-pressure steam consumption of the circulating hydrogen heater.

[0028] 3) Material flow: When starting up for the first time, close 4# valve and 3# valve, so that the silicon tetrachloride raw material from the STC feed pump directly enters the STC preheater; close 7# valve and 8# valve, so that the hydrogen raw material from the circulating hydrogen compressor directly enters the H2 preheater. When entering the production stage, close 2# valve, so that the silicon tetrachloride raw material from the STC feed pump first flows through the STC heat exchanger for heat exchange and then enters the STC preheater for temperature rise; close 6# valve, so that the hydrogen raw material from the circulating hydrogen compressor first flows through the H2 heat exchanger for heat exchange and then enters the H2 preheater for temperature rise. If problems such as failure of the STC heat exchanger and the H2 heat exchanger occur, close 3# valve, 4# valve, 7# valve and 8# valve, so that the silicon tetrachloride and hydrogen raw materials directly enter the preheater.

[0029] The implementation of the system scheme can effectively realize heat energy recovery in the cold hydrogenation process, improve the overall energy utilization efficiency, and reduce production costs. At the same time, it avoids the perforation of the low-pressure steam generator and the adverse effects on related equipment pipes from the source. This not only reduces the failure rate of the equipment and prolongs the service life of the equipment, but also eliminates the risk of material leakage and system emergency shutdown caused by heat exchanger perforation, thereby improving the safety and stability of the entire cold hydrogenation system.

[0030] The above-mentioned embodiments are only preferred technical solutions of the present application, and should not be regarded as limiting the present application. The protection scope of the present application should be based on the technical solutions claimed in the claims, including equivalent replacement schemes of the technical features claimed in the claims. That is, equivalent replacement improvements within this range are also within the protection scope of the present application.

Claims

1. A system for utilizing thermal energy between materials in a cold hydrogenation process, comprising a silicon tetrachloride preheater (1), a hydrogen preheater (2) and a reflux tank (3), characterized in that: The silicon tetrachloride preheater (1) is communicated with the silicon tetrachloride heat exchanger (4) through a pipeline, the silicon tetrachloride heat exchanger (4) is communicated with the hydrogen heat exchanger (5) through a pipeline, and the silicon tetrachloride heat exchanger (4) and the hydrogen heat exchanger (5) are communicated with the reflux tank (3) through pipelines.

2. A system for utilizing thermal energy between materials in a cold hydrogenation process according to claim 1, characterized in that: The hydrogen preheater (2) is communicated with the hydrogen heat exchanger (5).

3. A system for utilizing thermal energy between materials in a cold hydrogenation process according to claim 2, characterized in that: The silicon tetrachloride preheater (1) is communicated with the silicon tetrachloride heat exchanger (4) through a pipeline, the silicon tetrachloride heat exchanger (4) is communicated with the hydrogen heat exchanger (5) through a pipeline, and the silicon tetrachloride heat exchanger (4) and the hydrogen heat exchanger (5) are communicated with the reflux tank (3) through pipelines. The first pipeline is provided with a first valve and a second valve, and the second pipeline is provided with a fourth valve. The output end of the second valve is communicated with a third pipeline, the third pipeline is communicated with the feed inlet of the silicon tetrachloride heat exchanger (4), and the third pipeline is provided with a third valve.

4. A system for utilizing thermal energy between materials in a cold hydrogenation process according to claim 1, characterized in that: The hydrogen preheater (2) is communicated with the hydrogen heat exchanger (5) through a pipeline.

5. A system for utilizing thermal energy between materials in a cold hydrogenation process according to claim 4, characterized in that: The fourth pipeline is provided with a fifth valve and a sixth valve, and the fifth pipeline is provided with an eighth valve. The output end of the sixth valve is communicated with a sixth pipeline, the sixth pipeline is communicated with the feed inlet of the hydrogen heat exchanger (5), and the sixth pipeline is provided with a seventh valve. The silicon tetrachloride heat exchanger (4) and the hydrogen heat exchanger (5) are used for cooling the material of the crude trichlorosilane separation tower at the same time, and the cooled material flows back to the reflux tank (3).

6. A system for utilizing thermal energy between materials in a cold hydrogenation process according to claim 1, characterized in that: The silicon tetrachloride preheater (1) and the hydrogen preheater (2) are used for preheating the silicon tetrachloride, and then the silicon tetrachloride is introduced into the silicon tetrachloride vaporizer.

7. A system for utilizing thermal energy between materials in a cold hydrogenation process according to claim 1, characterized in that: ​

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