Essential details
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Product Introduction
Product use and characteristics
The shaft seal exhaust heater is an important equipment in the shaft seal system of steam turbine. It is used to pump the steam overflowing from the shaft seal of steam turbine to avoid discharging into the turbine room or entering the oil system, and recover the steam waste heat to ensure the safe and economic operation of the turbine unit.
The condensing, extraction and back pressure steam turbines of thermal power plants and self-owned power stations of industrial and mining enterprises are equipped with shaft sealing devices to avoid steam overflow. Structurally, the shaft seal is close to the bearing. Under the negative pressure of the bearing chamber. Steam escaping from the shaft seal easily enters the bearing seat. This is the main way of water in turbine oil. In the design of steam turbine thermal system. The shaft seal system has two types: open seat type and closed type. In this design, the pressure in the outer chamber of the shaft seal is higher than one atmosphere. The leaking steam exudes directly into the atmosphere. Steam is easy to be sucked into the bearing seat, and the operation is inconvenient, and the latter type is a closed shaft seal system. That is, in addition to the device for pumping and cooling the shaft seal steam, it is mostly used in large and medium-sized turbine units in China. Specifically, the exhaust device is used to pump the overflow steam outside the shaft seal and make it enter the heater to heat the condensate water. At the same time, the shaft seal steam is cooled into condensate water, which is recovered by the condenser because the shaft seal is blocked by negative pressure, the steam no longer spills. However, the current steam turbine manufacturers, the production of pumping heating devices are based on the traditional design of the manufacturers of production, a wide variety, most of the pumping and heating two parts are separated, and the pumping device is divided into shaft seal fan type, low pressure water ejector type, water ejector under the exhaust pump type and steam ejector type and other kinds of, plus a separate shaft seal heater. The device system of the above type is complicated in structure and operation. It is not suitable for medium and small wheel units.
This product "shaft seal air pumping heater" is a device that combines two processes of shaft seal air pumping and heating condensate water. It has the advantages of unique structure, simple system and stable operation condition. Moreover, the shaft seal air pumping device is adjustable, ensuring the reliability of operation and avoiding water in oil.
The shaft seal exhaust heater is an important equipment in the shaft seal system of steam turbine. It is used to pump the steam overflowing from the shaft seal of steam turbine to avoid discharging into the turbine room or entering the oil system, and recover the steam waste heat to ensure the safe and economic operation of the turbine unit.
The condensing, extraction and back pressure steam turbines of thermal power plants and self-owned power stations of industrial and mining enterprises are equipped with shaft sealing devices to avoid steam overflow. Structurally, the shaft seal is close to the bearing. Under the negative pressure of the bearing chamber. Steam escaping from the shaft seal easily enters the bearing seat. This is the main way of water in turbine oil. In the design of steam turbine thermal system. The shaft seal system has two types: open seat type and closed type. In this design, the pressure in the outer chamber of the shaft seal is higher than one atmosphere. The leaking steam exudes directly into the atmosphere. Steam is easy to be sucked into the bearing seat, and the operation is inconvenient, and the latter type is a closed shaft seal system. That is, in addition to the device for pumping and cooling the shaft seal steam, it is mostly used in large and medium-sized turbine units in China. Specifically, the exhaust device is used to pump the overflow steam outside the shaft seal and make it enter the heater to heat the condensate water. At the same time, the shaft seal steam is cooled into condensate water, which is recovered by the condenser because the shaft seal is blocked by negative pressure, the steam no longer spills. However, the current steam turbine manufacturers, the production of pumping heating devices are based on the traditional design of the manufacturers of production, a wide variety, most of the pumping and heating two parts are separated, and the pumping device is divided into shaft seal fan type, low pressure water ejector type, water ejector under the exhaust pump type and steam ejector type and other kinds of, plus a separate shaft seal heater. The device system of the above type is complicated in structure and operation. It is not suitable for medium and small wheel units.
This product "shaft seal air pumping heater" is a device that combines two processes of shaft seal air pumping and heating condensate water. It has the advantages of unique structure, simple system and stable operation condition. Moreover, the shaft seal air pumping device is adjustable, ensuring the reliability of operation and avoiding water in oil.
structure
The shaft seal heater is used in the shaft seal system of steam turbine. Its main function is to use condensate water to cool the gas-gas mixture extracted from the shaft seal and the stem of the high and medium pressure main steam regulating valve, and to form and maintain a certain vacuum in the steam side chamber of the shaft seal heater to prevent steam leakage from the shaft seal end. The vapor in the mixture condenses into water, thereby recovering the medium. The heat of the vapor-gas mixture is transferred to the condensate water, and the economy of the steam turbine thermal system is improved. At the same time, the temperature of the mixture is reduced to the temperature allowed by the long-term operation of the shaft sealing fan.
In the normal operation of the shaft seal heater, after the condensate water enters the water chamber of the shaft seal heater, part of the condensate water returns to the water outlet of the water chamber as cooling water through the U-shaped tube baffle, and the rest of the condensate water flows directly from the inlet chamber to the outlet chamber through the internal bypass valve. After the steam air mixture enters the shaft seal and heats the steam side shell, it moves back to flow outside the heat exchange tube (U-shaped tube), and carries out heat exchange with the cooling water through the heat exchange tube, so that the temperature of the suspected junction water rises, and most of the steam in the steam gas mixture condenses into water, and enters the condenser through the drain outlet pipe and the water seal tube. The gas and a small amount of steam are extracted and discharged into the atmosphere by the shaft seal fan.
The shaft seal heater is used in the shaft seal system of steam turbine. Its main function is to use condensate water to cool the gas-gas mixture extracted from the shaft seal and the stem of the high and medium pressure main steam regulating valve, and to form and maintain a certain vacuum in the steam side chamber of the shaft seal heater to prevent steam leakage from the shaft seal end. The vapor in the mixture condenses into water, thereby recovering the medium. The heat of the vapor-gas mixture is transferred to the condensate water, and the economy of the steam turbine thermal system is improved. At the same time, the temperature of the mixture is reduced to the temperature allowed by the long-term operation of the shaft sealing fan.
In the normal operation of the shaft seal heater, after the condensate water enters the water chamber of the shaft seal heater, part of the condensate water returns to the water outlet of the water chamber as cooling water through the U-shaped tube baffle, and the rest of the condensate water flows directly from the inlet chamber to the outlet chamber through the internal bypass valve. After the steam air mixture enters the shaft seal and heats the steam side shell, it moves back to flow outside the heat exchange tube (U-shaped tube), and carries out heat exchange with the cooling water through the heat exchange tube, so that the temperature of the suspected junction water rises, and most of the steam in the steam gas mixture condenses into water, and enters the condenser through the drain outlet pipe and the water seal tube. The gas and a small amount of steam are extracted and discharged into the atmosphere by the shaft seal fan.
Product specification
Product model | Heating area㎡ | Extractor suction pressureat | Working steam | Cooling water | Suitable for turbine models | ||||
stressMpa | Temperature ° C | Flow rate Kg/h | Water Resistance m | Temperature ° C | Flow rate Kg/h | ||||
JC-8/12 | 8/12 | ≈0.9 | 1.4 | 260-350 | 120 | 0.8 | 45～55 | 20～25 | N3、N6 |
JC-10/14 | 10/14 | ≈0.9 | 1.4 | 260-350 | 160 | 0.8 | 45～55 | 30 | N12 |
JC-10/20 | 10/20 | ≈0.9 | 1.4 | 260-350 | 200 | 0.8 | 45～55 | 35 | N25 |
Shaft seal exhaust heater installation
1, thermal system layout
The arrangement of the shaft seal exhaust heater in the thermal system is shown in Figure 2. The steam escape interface of the turbine shaft seal is connected with the interface heated in front of the shaft seal exhaust heater. The non-condensing gas discharged by the shaft seal exhaust heater is directly discharged into the atmosphere through the exhaust pipe, the drain water of the front and rear heaters is discharged into the low drain tank through a V-shaped tube, the condensation water pipe from the self-condensing device is connected with the inlet water pipe, and the outlet water pipe leads to the low pressure heater For the convenience of adjustment, the water pipe is also connected with a bypass pipe of the suction heater without shaft seal.
2, installation precautions
① The device is arranged horizontally.
② In order to facilitate drainage, the device adopts an arrangement above the zero meter layer, which can generally be installed on the operating layer of the heater, that is, on the platform between the zero meter layers of the operating layer.
(3) During installation, attention should be paid to the location of the cooling water inlet and outlet, which should not be reversed. The location of the cooling water inlet and the shaft seal steam inlet are located on the same side, and the location of the cooling water outlet and the ejector are located on the same side.
4 Should pay attention to the height of the V-shaped tube, the design principle is: the height of the water column of the V-shaped tube should be greater than the corresponding height of the water column of the negative pressure in the connected container.
(5) The air exhaust outlet is directly discharged by the pipeline, and the exhaust outlet of the pipeline can be arranged on the edge of the cypress rod and the pipe mouth outward, so as not to affect the passage of personnel.
⑥ Install a vacuum meter and a 0~100℃ temperature meter on the shaft seal steam inlet interface short pipe, and connect a 0~100℃ temperature meter on the cooling water inlet and outlet short pipe.
7 Water pressure test: This product has been tested before leaving the factory, but before installation and operation should still be in accordance with the "Power Construction and Acceptance Technical Code" (turbine unit part) principles, repeated tests, steam chamber part of the water pressure 0.2MPa, water chamber part of the water pressure 1.3MPa, five minutes of no leakage is qualified.
1, thermal system layout
The arrangement of the shaft seal exhaust heater in the thermal system is shown in Figure 2. The steam escape interface of the turbine shaft seal is connected with the interface heated in front of the shaft seal exhaust heater. The non-condensing gas discharged by the shaft seal exhaust heater is directly discharged into the atmosphere through the exhaust pipe, the drain water of the front and rear heaters is discharged into the low drain tank through a V-shaped tube, the condensation water pipe from the self-condensing device is connected with the inlet water pipe, and the outlet water pipe leads to the low pressure heater For the convenience of adjustment, the water pipe is also connected with a bypass pipe of the suction heater without shaft seal.
2, installation precautions
① The device is arranged horizontally.
② In order to facilitate drainage, the device adopts an arrangement above the zero meter layer, which can generally be installed on the operating layer of the heater, that is, on the platform between the zero meter layers of the operating layer.
(3) During installation, attention should be paid to the location of the cooling water inlet and outlet, which should not be reversed. The location of the cooling water inlet and the shaft seal steam inlet are located on the same side, and the location of the cooling water outlet and the ejector are located on the same side.
4 Should pay attention to the height of the V-shaped tube, the design principle is: the height of the water column of the V-shaped tube should be greater than the corresponding height of the water column of the negative pressure in the connected container.
(5) The air exhaust outlet is directly discharged by the pipeline, and the exhaust outlet of the pipeline can be arranged on the edge of the cypress rod and the pipe mouth outward, so as not to affect the passage of personnel.
⑥ Install a vacuum meter and a 0~100℃ temperature meter on the shaft seal steam inlet interface short pipe, and connect a 0~100℃ temperature meter on the cooling water inlet and outlet short pipe.
7 Water pressure test: This product has been tested before leaving the factory, but before installation and operation should still be in accordance with the "Power Construction and Acceptance Technical Code" (turbine unit part) principles, repeated tests, steam chamber part of the water pressure 0.2MPa, water chamber part of the water pressure 1.3MPa, five minutes of no leakage is qualified.
Product details
