Connection of turbine compressors

Turbines, steam turbines, and turbocompressors are different concepts. A turbine is the transliteration of the English word “turbine”; it refers to machines that convert the energy contained in a fluid into mechanical work； Turbine: A type of turbine (just as we say fruits and then apples, oranges, etc.). Turbines can be classified into hydroturbines, steam turbines, gas turbines, and air turbines, depending on the fluid medium used ； Turbine compressor: A type of compressor that is a dynamic compressor equipped with a high-speed rotating impeller.

Haha, the person on the 2nd floor is a doctor; they talked in very complex terms. In the chemical industry, a turbine-driven compressor refers to one in which a steam turbine drives the compressor; the connection between them is made via a coupling, and it definitely has a backup wheel. Its startup occurs simultaneously with the startup of the steam turbine, and warm-up is required.

Take a look; it might be helpful to the original poster. I. Starting of the steam turbine 1. Preparatory work before starting (1) Inspection of equipment and instruments； (2) Inspection of the plant power supply ； (3) Experiments on interlocking signals and inspection of protective devices ； (4) Inspection of the steam, water, and oil systems (especially inspection of the open and closed positions of pipeline valves) ； (5) The necessary liaison work with a series of relevant departments. 2. Heat the pipes and start the auxiliary equipment: Before starting the turbine, it is necessary to heat the steam pipes from the boiler to the turbine in sections. For small-scale units, the pipe warming before turbine startup mainly refers to the warming process of the pipeline between the isolation valve and the automatic main steam valve. Warming of the pipes behind the automatic main steam valve is carried out simultaneously with low-speed warm-up. ①Purpose of warming the pipes: (1) To prevent water hammer ； (2) To prevent excessive thermal stress from causing permanent deformation or even rupture of the pipes, thereby affecting the safety of the unit. ②Specific steps for heating the pipe: (1) Slightly open the isolation valve (or slowly open the bypass valve in units equipped with one), maintain the pressure inside the pipe at 2–3 kilograms/cm2, and heat the pipe at a rate of 5–10 degrees per minute℃ ； (2) Once the temperature of the inner wall of the pipe reaches 120–130°C, the pressure inside the pipe can be increased at a rate of 1–2 kilograms per square centimeter per minute, until it reaches the specified value. ③Precautions during pipe warming operations: (1) The temperature difference between various parts of the pipe should not be too large ； (2) The wall temperature shall not be lower than the saturation temperature at the corresponding pressure. Under the condition of meeting these two requirements, the pressure can be increased relatively quickly. ④Precautions: (1) Pipe heating usually takes place in two stages: low-pressure pipe heating and high-pressure pipe heating. To prevent excessive thermal stress from occurring inside the pipe during heating, both the heating process and the increase in pressure within the pipe should be carried out slowly; otherwise, the metal pipe wall will experience additional stress due to the temperature difference between the inside and outside. When this stress becomes too high, it can cause damage to the pipe. (2) To prevent water hammer caused by water accumulation inside the pipe, proper drainage must be carried out when heating the pipe. (When starting to warm the pipes, the drain valve should be opened wide to allow a large amount of condensate to be discharged promptly) ； As the wall temperature of the pipe and the pressure inside it increase, the amount of condensate produced gradually decreases. At this point, the steam trap should be gradually closed to prevent large amounts of steam from escaping and causing waste. ) (3) When warming up the pipes, it is necessary to close the automatic main steam valve tightly to prevent steam from leaking into the cylinders, which could cause deformation of the rotor and make starting difficult. (4) While warming the pipes, the circulation water pump should be started first; then water should be filled into the condenser space, the condensate water pump should be activated, and the recirculation valve should be opened to allow the condensate water to circulate between the ejector and the condenser. After that, turn on the main exhaust pump and the main steam valve of the starting exhaust pump to warm up the pipes. The start-up extractor can be activated in advance depending on the specific circumstances (for example, when air needs to be pumped out to fill the water for the circulation water pump to start). In order to conclude the pipe warming process as quickly as possible and reduce the startup time of the turbine, auxiliary equipment that uses steam should be started during this period, such as steam-driven oil pumps and extractors. It should be noted, however, that starting a steam-driven oil pump at low steam pressure is disadvantageous for small steam turbines; therefore, it should be brought into operation only when the steam pressure in the pipeline rises to a level sufficient to drive the small steam turbine. This approach allows an increased steam flow to the pipes, thereby reducing the time required for pipe warming. 3. Impulse rotor, low-speed warm-up: Before the turbine’s impulse rotor is started, equipment such as the circulating water pump, condensate water pump, and exhaust pump are already in operation to create the necessary starting vacuum. The level of the starting vacuum value has a certain impact on the economy and safety of the unit. The method of impulse rotor operation mainly depends on the specific characteristics of the turbine control system and the steam distribution mechanism; generally, it involves using bypass valves associated with the automatic main steam valve and the main steam gate. ①Automatic main steam valve rotor impulse method: All throttle valves are opened first, and the amount of steam entering the turbine during impulse is controlled by the automatic main steam valve. Advantages: Steam can be introduced through a full-circumference nozzle, resulting in more uniform heating of the turbine. Disadvantage: The automatic main steam valve wears out relatively quickly, which can lead to poor sealing and thus reduce the reliability of this protective device. ②The purpose of low-speed warming up is to heat the turbine evenly over a certain period of time, ensuring that thermal expansion, thermal stress, and thermal deformation in the parts exposed to steam remain within safe limits. ③Speed during low-speed warm-up: Currently, it is generally specified to be 10–15% of the rated speed. Too low a rotational speed makes it difficult to stabilize the control of the unit. ④During the low-speed warm-up phase, it is necessary to monitor: (1) Check the expansion of the unit ； (2) Conduct a thorough inspection and sound check of the unit ； (3) Changes in the temperature of the bearing lubricating oil. (Starting is not allowed when the oil temperature is below 25°C, and increasing speed is not allowed when it is below 30°C.) Under normal operation, the temperature of the lubricating oil supplied to the bearings should be within the range of 35–45°C. When the oil temperature is low, the viscosity is high, making it difficult to form an oil film between the bearing shells ； When the oil temperature is high, its viscosity is low, which in turn makes the oil film unstable. ) ⑤ Note: (1) To prevent the rotor from bending and to avoid friction between the moving and stationary parts that could cause shock to the rotor, it is necessary to rotate the rotor manually before starting it, in order to check the operating condition of the unit. (2) Once the start valve is operated to impulse the rotor, the steam valve should be immediately reduced to allow the turbine to warm up at a low speed. (3) An excessively long warm-up time inevitably increases the steam consumption required for starting the unit, reducing its operational efficiency ； An insufficient warm-up time fails to ensure even heating of the unit, affecting its safety. (4) When the oil temperature exceeds 40–45°C, cooling water must be supplied to the oil cooler in order to keep the oil temperature at the outlet of the cooler within the range of 35–45°C. 4. Speed increase: Speed increase refers to raising the speed of the turbine from its low speed during warm-up to the rated speed; this is a process of continued heating. ①Based on the operating experience of many units: (1) For low-pressure, low-capacity units, the speed can be increased by 10–15% of the rated speed per minute ； (2) For medium-pressure units, the speed can be increased at a rate of 5–10% per minute of the rated speed. But the general principle is that when increasing the speed, care must also be taken to ensure that the thermal expansion, thermal deformation, and thermal stress of the unit do not exceed the allowable values. ②At the rated speed, the turbine needs to be monitored for: (1) bearing vibration ； (2) Lubricating oil temperature ； (3) Thermal expansion of the cylinder ； (4) Differential expansion of cylinder and rotor ； (5) Rotor axial displacement ； (6) Exhaust temperature. Once it is confirmed that everything is normal, the protection system of the unit can be tested; after the protection equipment operates properly, the unit can be connected to a load. ③Note: (1) For turbines with flexible shafts (i.e., turbines operating at speeds higher than their critical speed), the critical speed should be crossed at a relatively fast rate during acceleration; it is not allowed to remain in the vicinity of the critical speed, as this can lead to resonance and cause accidents. (2) When accelerating, pay attention to whether the oil level in the tank, the oil flow in the bearings, and the oil temperatures at the inlet and outlet of the bearings are normal. (When a certain speed is reached, the main oil pump starts to operate; depending on the adjustment and the increase in lubricating oil pressure, the steam supply to the steam-driven oil pump should be gradually reduced until the steam-driven oil pump stops working entirely.) (3) In terms of the metal material of the exhaust cylinder, long-term operation below 250°C is generally safe. However, for the condenser copper tubes, it must be kept below 120°C; otherwise, the flanges will be damaged. To avoid high exhaust cylinder temperatures and prevent localized overheating in the turbine and condenser, it is generally not allowed for the turbine to operate at no load for extended periods. 5. Starting under load: The process of starting the unit under load is actually a continuation of the turbine’s heating process. To ensure that the thermal expansion, thermal deformation, and thermal stresses of various components of the turbine remain within acceptable limits, the rate at which load is applied must be controlled properly. Generally, the initial speed during load increase should be slower; for medium and low-pressure units, the increase in rated power should be around 5–10% per minute. However, in the later stages of load increase, the speed can be increased somewhat, reaching around 10–15% of the rated power per minute. If excessive vibration is detected during the loading process, the load must be reduced until the vibration disappears; only after stable operation for a period of time should the load be increased again. Note: (1) During the process of increasing speed or load, it is necessary to prevent the equipment from experiencing \"surge,\" and the \"surge zone\" should be avoided based on the equipment’s characteristic curve, in order to prevent damage to the equipment. (2) As the load increases, in condensing units, the condensation level in the condenser rises; therefore, it is necessary to adjust the condensate recirculation valve and the condensate outlet valve of the extractor in a timely manner to maintain a normal level in the hot well. (3) As the load increases, the pressure in the steam chamber of the regulating stage (speed stage) also rises. Once a certain pressure is reached, the shaft seal steam supply valve can be closed, allowing the steam leaking from the high-pressure side shaft seal to be used for the low-pressure side shaft seals. The excess steam can then be utilized to adjust the valves, with the surplus steam being discharged into the condenser.

I think a modular coupling should be used for connection, rather than a back pulley, because the turbine operates at high speeds

Connect the shafts of the turbine and compressor using a diaphragm coupling. A diaphragm coupling uses the elastic deformation of an extremely thin metal diaphragm to absorb deviations in the rotating shaft. The diaphragm has high torsional flexibility and is a key component of the coupling.

The steam turbines I’ve seen that are connected to compressors use diaphragm couplings.

The connection between turbines and compressors generally uses diaphragm couplings as well as gear sleeve couplings and gear drum couplings. Starting refers to the startup of the turbine, but the compressor also needs to meet the conditions for starting. After the turbine begins to operate at a constant speed, the compressor is loaded.

Isn’t a turbine just a steam turbine? Is there some other gas that can be used as a power source?

Thank you all. I am aware of the process of starting a turbine; since I have no experience with turbo compressors, my supervisor has assigned me tasks related to turbo compressors