Turbine seal air issues
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The company uses German 3K turbines; one turbine is paired with three sets of electrolyzers with an annual production capacity of 100,000 tons each. The turbines feature four stages of compression, with an outlet pressure of 0.63 Mpa, and they utilize nitrogen sealing. A portion of the sealed mixture is sent to the turbine inlet, while another portion is used for the absorption of emergency chlorine. For emergency chlorine, primary and secondary absorption towers are employed; the mixture is fed into the primary tower for absorption. The chlorine content in the mixture is 20%, which causes the concentration of the alkali solution used in the primary absorption process to drop rapidly. Currently, it is required that the concentration of the alkali in the primary stage remain above a certain percentage, so it is necessary to regularly add alkali to the solution containing emergency chlorine, which creates a significant burden. In the future, specialized absorption facilities will need to be installed. Do my colleagues in the chlor-alkali industry have any good solutions?
To address the issue of rapid decline in alkali solution concentration, the following solutions can be considered: 1. Adjust the operating parameters of the accident chlor-alkali absorption tower. A better absorption effect can be achieved by adjusting parameters such as the water inlet volume, circulation volume, and gas-liquid ratio, thereby reducing the concentration of chlorine introduced during the absorption process and slowing down the rate of decrease in the alkali solution concentration. 2. Treat the airflow at the turbine inlet. The chlorine concentration can be reduced by adding pre-treatment processes such as cooling, compression, and filtration of the exhaust gas, thereby lowering the concentration of chlorine that reaches the turbine. 3. Consider using effective chlorine absorption equipment. Efficient chlorine absorption technologies, such as oxidation and absorption methods, can be used to remove chlorine from waste gases, thereby reducing the burden associated with preparing alkaline solutions in the plant. 4. Appropriately increase the frequency of adding alkali to the chlor-alkali solution in case of an accident. Depending on the production conditions of the line, the frequency of adding alkali can be increased appropriately, in order to maintain a stable concentration of primary alkaline solution while preserving the efficiency of the equipment. Through the above measures, the problem of rapid decline in the concentration of alkaline solution in the waste gas treatment of turbines can be effectively addressed, and the operational efficiency of the equipment can be improved. For reference only
Some of the devices are described in a rather superficial manner; there are many reasons for this – sometimes it’s due to immature manufacturing processes or issues with equipment operation. In short, there are numerous reasons, and it’s hard to specify exactly what the problem is. One can only try to identify where the issue lies. There are also many people who take advantage of others here; technology is indeed valuable. It’s normal if you don’t agree with this; after all, you may not have a formal background in technology
The sealing gas can be completely returned to the inlet; its purity is acceptable, and it contains little chlorine. Is it the sealing gas that causes the decrease in the concentration of the alkaline solution?
It’s probably a process-related issue. Even at an export pressure of over 1 megapascal, we don’t experience the problem you mentioned. Once, our liquid chlorine compressor stopped working, but when raw chlorine flowed in as emergency chlorine, nothing happened immediately!
There is little chlorine in the seal gas from the normal turbine to the emergency chlorine system; check whether there are any other issues