Connection method between hydraulic recovery turbines and pumps
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The hydraulic turbine is used for the recovery of high-pressure rich liquid capacity in the ammonia synthesis decarburization process, driving the lean liquid pump to operate. After checking some information, it seems that the following types are currently in use in China: 1. Turbine + overrunning clutch + motor + pump; 2. Turbine + coupling + pump. Solution 1 appears to be more widely used, but the overrunning clutch has a relatively high failure rate. Solution 2 requires higher technical standards but is more stable. According to the information available, Sichuan Meifeng uses this approach for its 200,000-ton synthetic ammonia production facility, with a power recovery rate of 370 kW. Both the turbine and the pump are products from Niigata Worthington in Japan. The website of Lanzhou Xiyu Pump Industry also lists such products, but no examples of their use in China have been found. For higher-power energy recovery, if the hydraulic conditions are relatively stable, which approach is better? Does the coupling in Option 2 also have a clutch function to prevent high speeds? What form is that type of coupling usually taken? Can a diaphragm type be used? Thank you!
Zhejiang Jialite Pump Industry has such hydraulic turbines, and our company is using them
It’s not that complicated; a regular diaphragm coupling will do, and the technical requirements aren’t high. Compared to steam turbines, hydraulic turbines are much easier to operate.
For the second type of connection, how is the rotation speed controlled? Is there real-time monitoring? Thank you
It is directly controlled by the inlet control valve of the hydraulic turbine, and it features real-time speed monitoring; generally, such pumps are not very large in size.
In the domestic petrochemical industry, Marland’s hydraulic couplers are widely used, and I haven’t heard much about them being prone to failure. Option 1 is more general; for Option 2, the amount of rich liquid is not guaranteed.
It can also be controlled by the pressure difference before and after the turbine, and this effect is quite noticeable.
Our company uses the complete package from Calvert Ebara; at first we suspected that its performance might not be sufficient, but after testing it under full load, we found that its performance is excellent and its operation is very stable. Warm-up startup can be controlled through the level control valve and the inlet electric valve. Adjusting the speed at runtime is generally achieved by fine-tuning the system backpressure or by adjusting the turbine backpressure.
Adjusting the back pressure: Taking the decarburization process in ammonia synthesis as an example, adjusting the pressures at the inlet and outlet of the turbine essentially means adjusting the back pressure in the absorption tower and the regeneration tower. This requires taking into account the effects of various parameters in the process system; it is generally done sparingly, and such adjustments also have a significant impact on subsequent processes, which is why this method is rarely used.
That makes sense. However, the system backpressure can sometimes experience slight fluctuations, which clearly affect the turbine speed; in such cases, it is necessary for us to adjust the backpressure promptly. Regarding flow rate, if the decarbonization system is stable, the liquid level generally will not change either.
Thank you for your reply; the issue is now pretty clear. Thank you