Auxiliary water supply steam pump

Abstract

The present invention discloses an auxiliary feedwater pneumatic pump, comprising a pump casing, a pump cover, a steam turbine, a pump shaft, a rotor, an axial force balancing device, a speed controller and an intelligent pump group diagnostic system. The rotor mainly comprises an inducer, a first-stage impeller and a secondary impeller. The pump cover is arranged on one side of the pump casing, and a conical guide cap is arranged inside the pump cover; one end of the steam turbine is connected to the other side of the pump casing, and a cylinder cover is arranged at the other end of the steam turbine; a steam turbine impeller and a nozzle group adjacent thereto are arranged inside the steam turbine; the inducer, the first-stage impeller, the secondary impeller, the axial force balancing device and the steam turbine impeller are arranged on the pump shaft in sequence; the steam turbine impeller is connected to the pump shaft by a key. The auxiliary feedwater pneumatic pump of the present invention can replace damaged moving blades or stationary blades of the steam turbine separately, reducing the maintenance cost of the steam turbine. By adding an intelligent pump group diagnostic system, online data collection, fault diagnosis and full life cycle management can be realized.

Description

Technical Field

[0001] The invention relates to an auxiliary water supply pneumatic pump. Background Art

[0002] The auxiliary feedwater pneumatic pump is used in the Hualong One reactor type nuclear power plant. It is a nuclear safety third-level pump of the nuclear power plant. It plays the important role of providing water to the steam generator when the main feedwater system is unavailable.

[0003] At present, the rated speed and trip speed of the auxiliary water supply pneumatic pump are high, the stress on the parts during operation is large, the service life is short, and the vibration and noise are large; the turbine impeller and nozzle group adopt an integrated design and processing, which is complex and difficult to manufacture. As long as one blade of the turbine impeller or nozzle group is damaged, the parts need to be replaced as a whole, and the maintenance cost is high; the turbine impeller and the pump shaft are connected by end face teeth, which is difficult to process and costly, and the end face tooth connection part needs to be prepared and is not interchangeable. When replacing one of the impeller or pump shaft, the other part needs to be replaced at the same time, and the maintenance cost is high. The turbine impeller blades have no blade crowns, the blade strength is low and the efficiency is low; the pump group has no intelligent diagnosis system, and it is impossible to quickly diagnose the cause of the failure during the operation of the pump, and it is impossible to monitor in real time to ensure the safe and reliable operation of the pump group, and it is impossible to fully record the operation data of the pump group throughout its life cycle. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide an auxiliary feedwater pneumatic pump, which can replace the damaged moving blades or stationary blades of the steam turbine separately, thereby reducing the maintenance cost of the steam turbine, adding an intelligent pump group diagnostic system, collecting operating data online in real time, and providing early warning and evaluation of abnormal operating conditions, so as to realize rapid diagnosis and analysis of fault causes and full life cycle management.

[0005] The technical solution to achieve the above object is: an auxiliary water supply steam-driven pump, including a pump housing, a pump cover, a steam turbine, a pump shaft, a rotor, an axial force balancing device, a speed controller and an intelligent pump group diagnostic system, wherein the rotor mainly includes an inducer, a primary impeller and a secondary impeller, wherein:

[0006] The pump housing is arranged transversely, and a pump outlet is arranged at the upper end of the pump housing;

[0007] The pump cover is arranged on one side of the pump housing, and a conical flow guide cap is arranged inside the pump cover;

[0008] One end of the steam turbine is connected to the other side of the pump housing, and the other end of the steam turbine is provided with a cylinder head; a steam turbine impeller and a nozzle group adjacent thereto are provided inside the steam turbine;

[0009] The pump shaft is transversely arranged in the pump housing, the inducer, the first-stage impeller, the secondary impeller, the axial force balancing device and the steam turbine impeller are arranged on the pump shaft in sequence, and a central water chamber is arranged between the steam turbine impeller and the axial force balancing device;

[0010] The steam turbine impeller is connected to the pump shaft via a key;

[0011] A speed probe is arranged in the central water chamber, a steam bypass solenoid valve is installed on the steam turbine via a fixed bracket, and the speed controller communicates with the speed probe and the steam bypass solenoid valve respectively;

[0012] Vibration sensors are respectively arranged on the mouth ring of the first-stage impeller and above the central water chamber, and the intelligent pump group diagnostic system communicates with the vibration sensors.

[0013] In the above-mentioned auxiliary feedwater pneumatic pump, the steam turbine is a single-stage back-pressure steam turbine.

[0014] In the above-mentioned auxiliary water supply steam-driven pump, the steam turbine and the pump casing are integrally cast.

[0015] In the above-mentioned auxiliary water supply pneumatic pump, the speed controller adopts a digital speed controller.

[0016] In the above-mentioned auxiliary water supply steam-driven pump, the steam turbine impeller adopts inlaid moving blades, and each moving blade of the steam turbine impeller has a blade crown; the nozzle group adopts inlaid stationary blades.

[0017] The above-mentioned auxiliary water supply pneumatic pump, wherein the auxiliary water supply pneumatic pump is provided with two overspeed release devices, one is an electronic overspeed release device, the electronic overspeed release device is mainly composed of the speed probe, the speed controller and the steam bypass solenoid valve; the other is a mechanical overspeed release device, which is executed by a mechanical flyweight installed in the pump shaft.

[0018] The above-mentioned auxiliary water supply pneumatic pump, wherein the intelligent pump group diagnostic system is used to collect the operating data of the auxiliary water supply pneumatic pump in real time online, to warn and evaluate the abnormal operating status, and to achieve rapid diagnosis and analysis of the cause of the fault and full life cycle management.

[0019] Compared with the prior art, the auxiliary water supply pneumatic pump of the present invention has the following beneficial effects:

[0020] 1) The turbine impeller adopts inlaid blades (moving blades), each moving blade has a blade crown, and the moving blades are processed independently, which improves the blade strength, simplifies the production process of the turbine impeller, and reduces the production cost. When the moving blade is damaged, the damaged blade can be replaced separately, which reduces the maintenance cost of the turbine and improves the efficiency of the pump unit;

[0021] 2) The nozzle group adopts inlaid blades (stationary blades), and the stationary blades are processed independently, which simplifies the production process of the nozzle group and reduces the production cost. When the stationary blades are damaged, the damaged stationary blades can be replaced separately, which reduces the maintenance cost of the steam turbine;

[0022] 3) The original turbine impeller and pump shaft end face tooth connection structure was cancelled, and a cylindrical hole connection was adopted, and the torque was transmitted by a key, which simplified the manufacturing process of the turbine impeller and the pump shaft, reduced the production cost without reducing the reliability of the pump unit, and improved the interchangeability of parts;

[0023] 4) The rated speed of the pump set is reduced, and at the same time, the tripping speed is reduced, the stress of the components of the pump set during operation is reduced, the service life of the components of the pump set is increased, and the reliability of the pump set is improved;

[0024] 5) Add intelligent pump group diagnostics to collect operating data online in real time, provide early warning and evaluation of abnormal operating conditions, and achieve rapid diagnosis and analysis of fault causes and full life cycle management. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the auxiliary water supply pneumatic pump of the present invention. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the technical solution of the present invention, the specific implementation methods thereof are described in detail below in conjunction with the accompanying drawings:

[0027] See also Figure 1 The best embodiment of the present invention is an auxiliary water supply steam-driven pump, which is a horizontal two-stage centrifugal pump, mainly including a pump casing 1, a pump cover 3, a steam turbine 6, a pump shaft 4, a rotor 2, an axial force balancing device 5, a speed controller (not shown in the figure) and an intelligent pump group diagnostic system (not shown in the figure), and the rotor 2 mainly includes an inducer 21, a first-stage impeller 22 and a secondary impeller 23.

[0028] The pump housing 1 is arranged horizontally, and a pump outlet 11 is arranged at the upper end of the pump housing 1; a pump cover 3 is arranged on one side of the pump housing, and a conical guide cap 31 is arranged inside the pump cover 3; one end of the steam turbine 6 is connected to the other side of the pump housing 1, and a cylinder cover 61 is arranged at the other end of the steam turbine 6; a turbine impeller 62 and a nozzle group 63 adjacent to it are arranged inside the steam turbine 6.

[0029] The pump shaft 4 is transversely arranged in the pump housing 1, and the inducer 21, the first-stage impeller 22, the secondary impeller 23, the axial force balancing device 5 and the turbine impeller 62 are arranged on the pump shaft 4 in sequence, and a central water chamber 7 is arranged between the turbine impeller 62 and the axial force balancing device 5.

[0030] The turbine impeller 62 is connected to the pump shaft 4 by a key; the original turbine impeller and pump shaft end face tooth connection structure is cancelled, and a cylindrical hole connection is adopted, and the torque is transmitted by a key, which simplifies the manufacturing process of the turbine impeller and the pump shaft, reduces the production cost without reducing the reliability of the pump group, and improves the interchangeability of parts.

[0031] A speed probe is provided in the central water chamber 7, a steam bypass solenoid valve is installed on the steam turbine 6 through a fixed bracket, and the speed controller communicates with the speed probe and the steam bypass solenoid valve respectively; the manufacturer of the speed controller is Jiangsu Lihe Instrument and Control Technology Co., Ltd., the model is TC-50N, the speed controller is fixed on the panel of the local control cabinet, receives the signal of the speed probe, compares it with the set speed in the speed controller, and outputs the control signal to the pneumatic actuator to adjust the opening of the control valve, thereby realizing the speed control,

[0032] Vibration sensors are respectively arranged on the mouth ring of the first-stage impeller 22 and above the central water chamber 7, and the intelligent pump group diagnostic system communicates with the vibration sensor. The vibration signal measured by the vibration sensor is transmitted to the intelligent pump group diagnostic system in the local control cabinet (local TSI cabinet). If the vibration value exceeds the set value, an alarm signal is issued to prompt inspection. At the same time, maintenance suggestions are given based on the vibration data collected during operation.

[0033] The steam turbine 6 adopts a single-stage back-pressure steam turbine. The auxiliary feed water pneumatic pump of the present invention is driven by a single-stage back-pressure steam turbine. The steam turbine 6 and the pump casing are integrally cast. The steam turbine impeller 62 and the two-stage impeller and inducer of the pump are installed on the same pump shaft 4. The pump shaft 4 is lubricated and cooled by water drawn from the first-stage impeller 22. The weight of the entire rotor 2 and the radial force generated during operation are borne by two water-lubricated radial bearings installed in the central water chamber; the axial force generated by the rotor 2 during operation is borne by the axial force balancing device 5. The axial force balancing device 5 can adopt the structure in the patent with application number CN201920463096.3. The axial force balancing device 5 includes a balancing disc, a balancing plate and a thrust ring.

[0034] The speed controller adopts a digital speed controller to achieve stepless speed change, stable speed with small fluctuation, and a digital speed regulation system to achieve overspeed test. The pump will not have cavitation, and the pump unit is safer and more reliable.

[0035] There are two overspeed release devices in the auxiliary feedwater steam-driven pump. One is an electronic overspeed release device, which is executed by the speed of the pump shaft monitored by an electronic tachometer. Specifically, the electronic overspeed release device is mainly composed of a speed probe (installed in the central water chamber of the pump body), a speed controller (installed on the local control cabinet panel) and a steam bypass solenoid valve (installed on the fixed bracket at the turbine end). The speed probe measures the speed and sends it to the speed controller. When the speed reaches or exceeds the set trip speed of the speed controller, the speed controller outputs a signal to the steam bypass solenoid valve to open the solenoid valve, close the turbine speed valve, and bypass the steam, thereby shutting down the machine. The other is a mechanical overspeed release device, which is executed by a mechanical flyweight installed in the pump shaft.

[0036] The turbine impeller 62 adopts inlaid moving blades. Each moving blade of the turbine impeller has a blade crown. The moving blades are independently processed, the blade strength is improved, the production process of the turbine impeller is simplified, and the production cost is reduced. When the moving blades are damaged, the damaged moving blades can be replaced separately, which reduces the maintenance cost of the turbine and improves the efficiency of the pump group.

[0037] The nozzle group 63 uses an inlaid stationary blade. The stationary blade is processed independently, which simplifies the production process of the nozzle group and reduces the production cost. When the stationary blade is damaged, the damaged stationary blade can be replaced separately, which reduces the maintenance cost of the steam turbine.

[0038] The intelligent pump group diagnosis system is used to collect the operating data of the auxiliary water supply pneumatic pump in real time online, to warn and evaluate abnormal operating conditions, and to achieve rapid diagnosis and analysis of fault causes and full life cycle management.

[0039] In summary, the auxiliary feedwater pneumatic pump of the present invention can replace damaged moving blades or stationary blades of the steam turbine independently, thereby reducing the maintenance cost of the steam turbine. By adding an intelligent pump group diagnostic system, online data collection, fault diagnosis and full life cycle management can be realized.

[0040] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. An auxiliary water supply pneumatic pump, characterized in that: It includes a pump casing, a pump cover, a steam turbine, a pump shaft, a rotor, an axial force balancing device, a speed controller and an intelligent pump group diagnostic system, wherein the rotor includes an inducer, a primary impeller and a secondary impeller, wherein: The pump housing is arranged transversely, and a pump outlet is arranged at the upper end of the pump housing; The pump cover is arranged on one side of the pump housing, and a conical flow guide cap is arranged inside the pump cover; One end of the steam turbine is connected to the other side of the pump housing, and the other end of the steam turbine is provided with a cylinder head; a steam turbine impeller and a nozzle group adjacent thereto are provided inside the steam turbine; The pump shaft is transversely arranged in the pump housing, the inducer, the first-stage impeller, the secondary impeller, the axial force balancing device and the steam turbine impeller are arranged on the pump shaft in sequence, and a central water chamber is arranged between the steam turbine impeller and the axial force balancing device; The steam turbine impeller is connected to the pump shaft via a key; A speed probe is arranged in the central water chamber, a steam bypass solenoid valve is installed on the steam turbine via a fixed bracket, and the speed controller communicates with the speed probe and the steam bypass solenoid valve respectively; Vibration sensors are respectively arranged on the mouth ring of the first-stage impeller and above the central water chamber, and the intelligent pump group diagnostic system communicates with the vibration sensors. The steam turbine impeller adopts inlaid moving blades, and each moving blade of the steam turbine impeller is provided with a blade crown; The nozzle group adopts inlaid stationary blades; The intelligent pump group diagnostic system is used to collect the operating data of the auxiliary water supply pneumatic pump in real time online, to warn and evaluate the abnormal operating state, to achieve rapid diagnosis and analysis of the cause of the fault and full life cycle management. The auxiliary water supply steam driven pump is provided with two overspeed tripping devices, one is an electronic overspeed tripping device, which is composed of the speed probe, the speed controller and the steam bypass solenoid valve; the other is a mechanical overspeed tripping device, which is executed by a mechanical flyweight installed in the pump shaft. The moving blades are processed independently, the blade strength is improved, and the production process of the turbine impeller is simplified. When the moving blades are damaged, the damaged blades can be replaced separately. The stationary blades are processed independently, which simplifies the production process of the nozzle group. When the stationary blades are damaged, the damaged stationary blades can be replaced separately.

2. The auxiliary water supply pneumatic pump according to claim 1, characterized in that: The steam turbine is a single-stage back-pressure steam turbine.

3. The auxiliary water supply pneumatic pump according to claim 1, characterized in that: The steam turbine and the pump casing are integrally cast.

4. The auxiliary water supply pneumatic pump according to claim 1, characterized in that: The speed controller is a digital speed controller.

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