19 results about "NPSH" patented technology

The invention provides a steam turbine generator unit feed pump net positive suction head detection system and method, relates to the technical field of net positive suction detection, and solves the technical problem that net positive suction is difficult to recognize in advance in the prior art. The system specifically comprises a temperature acquisition module used for acquiring the temperature of the deaerator; the judgment and early warning module is used for receiving the flow change rate of the feed pump and triggering alarm when the flow change rate exceeds a flow threshold value; the effective net positive suction head calculation module is used for converting the inlet pressure of the water feeding pump into absolute pressure; temperature correction is conducted on the temperature of the deaerator to obtain the saturation temperature of an inlet of the water feeding pump, the saturation temperature is converted into saturated vapor pressure, and the effective net positive suction head is calculated based on the absolute pressure and the saturated vapor pressure; the necessary net positive suction head obtaining module is used for calling the necessary net positive suction head table and calculating and obtaining the necessary net positive suction head; and the net positive suction head calculation module is used for receiving the effective net positive suction head and the necessary net positive suction head and calculating the net positive suction head. The device is used for detecting the net positive suction head.

This application provides a high-cavitation-resistant pressure-reducing sludge pump, belonging to the field of centrifugal pump technology. Because the pump transports a high-temperature medium with a low inlet pressure, the medium at the pump inlet is in a critical saturation state. At this point, the medium is highly susceptible to vaporization, forming a large number of bubbles. The bursting of these bubbles generates impact, causing cavitation damage to the inlet blades of the first-stage impeller, resulting in pump vibration, noise, and a sudden drop in head, ultimately leading to pump damage. Increasing the pump inlet pressure and decreasing the medium temperature are not feasible. The only solution is to optimize the pump body. Since the inlet of the first-stage impeller is highly susceptible to cavitation, the first-stage impeller is designed with double suction to increase the pump's net positive suction head (NPSH), thereby reducing the possibility of cavitation in the first-stage impeller and ensuring more stable pump operation. Due to the high pump outlet pressure, the coordinated operation of the first and second-stage impellers can mitigate excessive pressure on individual impeller components, thus extending the pump's service life.

The invention discloses a cavitation heating method and system based on artificial intelligence. The method comprises the steps that sound data from an acoustic sensor and vibration data from a vibration sensor are obtained; acquiring other data from other sensors; performing time-frequency domain analysis on the sound data and the vibration data; associating the processed sound data, vibration data and other sensor data according to a time axis; training a machine learning model by using multiple groups of training data; and obtaining input data according to sensor data collected in real time and the net positive suction head NPSH value obtained through calculation, inputting the input data into the machine learning model, and outputting the current or future cavitation state of the cavitation heating device in the machine learning model. The problem that monitoring of a single parameter is not beneficial to inaccurate judgment of the cavitation heating operation state is solved, and therefore the accuracy of the operation state of the cavitation heating device is improved to a certain degree.

The present application relates to the technical field of boiler feed water pump cavitation control, and discloses a self-adaptive adjustment method and system for preventing cavitation of a boiler feed water pump, which acquires the inlet pressure, inlet water temperature and feed water flow of the pump in real time, calculates the effective net positive suction head NPSHa and looks up the required net positive suction head NPSHr, calculates the margin coefficient and makes a judgment, and drives the frequency converter and the inlet regulating valve to adjust in coordination according to the judgment result. The system comprises a parameter acquisition unit, a self-adaptive controller, an actuator and a man-machine interaction unit. The present application can effectively prevent cavitation from occurring and reduce the energy consumption of the feed water pump by real-time dynamic calculation and coordinated adjustment of the net positive suction head, and can adapt to the nonlinear pressure variation characteristics of sliding pressure operation, and balance the rapidity of cavitation protection and the economy of operation.

The application relates to the technical field of cryogenic pump testing, and provides a liquid hydrogen pump testing system and a testing method thereof, the liquid hydrogen pump testing system comprising a low-temperature testing end assembly, a fluid charging and discharging module connected to the low-temperature testing end assembly, and an automatic control system for controlling valves of the liquid hydrogen pump testing system; the liquid hydrogen pump testing system is provided with a cold box and can meet the testing requirement of the performance and critical net positive suction head of a pump under a low-temperature environment of not less than 20K (especially under a 20K liquid hydrogen and 77K liquid nitrogen environment); by testing key parameters such as temperature, pressure, flow rate and liquid level, the external characteristics and cavitation characteristics of a centrifugal submerged pump and a pipeline pump under different inlet pressures and flow rates in a liquid hydrogen temperature zone can be tested and evaluated; by testing the performance of the pump under actual operation conditions, the actual performance of the pump can be accurately evaluated and guidance can be provided for research and development and improvement work.

The utility model discloses a centrifugal pump impeller structure capable of changing the net positive suction head, which comprises a middle shaft, an inner impeller and an outer impeller, the middle shaft is arranged at an inlet of a pump shell, a power shaft penetrates through an assembly hole in the middle shaft, the inner end face of the middle shaft abuts against the inner impeller, and a fixing nut is arranged at the outer end of the middle shaft and is positioned with the outer end of the power shaft; the spiral blades are evenly distributed on the surface of the middle shaft, the inner end face and the outer end face of each spiral blade are provided with a first wedge-shaped arc face and a second wedge-shaped arc face respectively, and gaps are reserved between the inlets and the spiral blades. The centrifugal pump can solve the problems that when an existing centrifugal pump is used, the cavitation phenomenon is prone to being generated, the operation performance of the pump is reduced, and the service life is shortened.

The invention discloses an energy-saving vertical circulating water pump, and relates to the technical field of vertical centrifugal pumps. The invention provides an energy-saving vertical circulating water pump which comprises a pump body, an impeller is rotationally connected into the pump body, the static pressure and the net positive suction head of a water inlet of the pump body both exceed 12 m, a support is fixedly connected to the top of the pump body, and a motor is fixedly installed at the top of the support. The vertical centrifugal pump with the lift of 35 m, the flow of 200 m < 3 > / h and the motor power of 30 kW is selected, meanwhile, the static pressure of an inlet of the vertical centrifugal pump exceeds 12 m and the net positive suction head exceeds 12 m under the conditions that measures are adjusted to local conditions, huge static pressure is utilized, and under the conditions of the same flow and the same power, due to the fact that the static pressure is especially large, the pump body runs stably, and the service life of the pump body is prolonged. And meanwhile, the lift of the pump is improved, considerable energy (electric energy) is saved, the structure is reasonable, noise is low during operation, and stability and reliability are high.

The utility model relates to an anti-vortex single-stage pump with a non-return function. The anti-vortex single-stage pump is characterized by comprising a connecting cover, a motor, a pump body, an impeller, a non-return valve and a sensor, the motor is fixedly mounted at the top of the connecting cover; the pump body is fixedly installed at the bottom of the connecting cover and horizontally arranged, a water inlet and a water outlet are formed in the two ends of the pump body respectively, and a vertical anti-vortex plate is fixed to the position, located at the water inlet of the impeller, in the pump body. The impeller is arranged in the pump body and is fixedly connected with an output shaft of the motor; the check valve is fixedly mounted in the water inlet of the pump body; and the sensor is fixed in the connecting cover. The check valve is fixedly installed in the water inlet of the pump body, the sensor is fixed in the connecting cover and integrally arranged in a pump body unit, the size of a water pump system is reduced, meanwhile, fault nodes are reduced, the vertical vortex prevention plate is fixed to the position, located at the water inlet of the impeller, in the pump body, and the vortex prevention plate is not prone to falling off. The anti-vortex plate can prevent the situation that pre-rotation is generated, vortex is formed, and the unit efficiency and the net positive suction head are affected.

The application relates to the technical field of water supply, in particular to a water supply pump state detection device and method. The water supply pump state detection device comprises a water supply pump, a pressure detection unit, a vibration detection unit and a water pressure pulsation detection unit; the pressure detection unit is connected with the water supply pump and is used for detecting the pressure of the inlet and outlet of the water supply pump; the vibration detection unit is connected with the water supply pump and is used for detecting the vibration of the water supply pump; the water pressure pulsation detection unit is connected with the water supply pump and is used for detecting the water pressure pulsation of the water supply pump. The water supply pump state detection device can monitor the inlet and outlet pressure, water pressure pulsation data and mechanical vibration data in real time, and can analyze the data, comprehensively consider the rated parameters such as the lift and the net positive suction head of the water supply pump, thereby giving potential fault early warning and cause diagnosis of the water supply pump, so as to propose corresponding predictive maintenance solutions.

This invention discloses a method and system for controlling the net positive suction head (NPSH) of feedwater pump sets in thermal power plants, belonging to the field of automatic control technology for thermal power generating units. The method involves obtaining the actual available NPSH at the feedwater pump inlet to determine the lower limit of allowable deaerator pressure variation; obtaining the time required for water to flow from the deaerator to the feedwater pump inlet; obtaining the condensate flow increment to prevent insufficient NPSH based on the lower limit of deaerator pressure variation and the time; determining the condensate flow limit value to prevent insufficient NPSH; limiting the output of the automatic deaerator level control module when the actual condensate flow is greater than the condensate flow limit value; and ensuring the automatic deaerator level control module operates normally when the actual condensate flow is less than the condensate flow limit value or when the condensate flow increment is negative. This method prevents insufficient NPSH in feedwater pump sets by limiting condensate flow under emergency conditions, thereby improving the safety and stability of thermal power plant operation.

The utility model discloses an automatic liquid level control system and decompression equipment applying the same, the automatic liquid level control system is used for a decompression device and comprises a liquid seal device, a liquid level sensing mechanism and a tower bottom product pump, a liquid inlet pipeline of the liquid seal device is communicated with the side wall of a tower body of the decompression device, and a liquid outlet pipeline of the liquid level sensing mechanism is communicated with the tower bottom product pump. A liquid outlet pipeline of the liquid sealing device is communicated with a liquid outlet pipeline of the pressure reducing device, the tower bottom product pump is communicated with the liquid outlet pipeline of the liquid sealing device and the liquid outlet pipeline of the pressure reducing device, and the tower bottom product pump is also connected with the liquid level sensing mechanism to realize pressure balance. According to the automatic liquid level control system, the liquid level sensing mechanism is adopted to control the rotating speed of the product extraction pump, so that the net positive suction head of the tower bottom product pump is counteracted, the stability of liquid drainage of the tower bottom product pump in a pressure reduction state is improved, and the problem that the product pump is damaged due to small height difference between a pressure reduction device and the tower bottom product pump is solved. And the phenomenon that a product pump at the bottom of the tower does not discharge liquid or the liquid discharge is unstable due to insufficient feeding pressure heads is avoided.

According to the double-end liquid inlet impeller for the self-priming pump, a rotating shaft is fixedly arranged in the center of the impeller in a penetrating mode, the impeller is a hollow disc-shaped impeller, arc-shaped blades are transversely arranged in the center of the interior of the impeller, and an upper end water inlet and a lower end water inlet are formed in the upper end and the lower end of a shell of the impeller respectively; an outer side water outlet is formed in the arc-shaped outer side of a shell of the impeller, a connecting middle shaft is arranged at the bottom of the center of an arc-shaped blade, the outer side edge of the arc-shaped blade is flush with the transverse horizontal center line of the outer side water outlet, and a layer of inner pump shell is additionally arranged on the outer side of the impeller through water inlets formed in the upper end and the lower end. Water flowing in from two ends is pressurized and integrated, so that small net positive suction head can be effectively realized, the suction lift is greatly improved, and the suction lift can reach 8 meters under normal pressure.

The utility model relates to a centrifugal impeller, including upper end disc, lower end disc and a plurality of long blades, the central place of lower end disc is provided with the use assembly unit, the assembly unit is provided with the shaft hole, the assembly unit includes upper end and lower end, long blade is arc and surrounds the upper end part setting, upper end disc is provided with the water inlet part, the central place of water inlet part is provided with the water inlet, the inner diameter of water inlet is greater than the diameter of upper end, long blade includes connecting part and the extension from the connecting part to the upper end part periphery from top to bottom, the side of extension is arc and sets up and with the side of connecting part smooth transition, the upper end surface of extension is inclined and sets up and the same as long blade arc rotation direction with the inclined direction, the short blade that is arc is provided between adjacent long blades, short blade sets up in connecting part one end close to extension. Through adopting above technical scheme, reduce the necessary net positive suction head of pump, promote the anticavitation performance, effectively divide the runner, restrain the bad vortex and secondary flow, reduce the flow loss.

The application discloses an anti-cavitation impeller, and relates to the technical field of centrifugal pumps. Each group of blade units comprises an inlet edge forward blade and a regular blade, and the inlet edge forward blade and the regular blade are arranged alternately in the circumferential direction; the radially outermost edge of the inlet edge of the inlet edge forward blade is located radially outward of the radially outermost edge of the inlet edge of the regular blade; the radially innermost edge of the inlet edge of the regular blade is located radially inward of the radially innermost edge of the inlet edge of the inlet edge forward blade; and the spacing angles between any two adjacent groups of blade units are not equal. Therefore, the impeller of the embodiment of the application can maintain stable anti-cavitation performance in a wide flow range, is not only suitable for the delivery of high-temperature easy-vaporization medium with a super-low net positive suction head, but also lays a good flow field foundation for subsequent adaptation to gas-liquid two-phase flow conditions, and effectively improves the operation stability and working condition adaptability of the chemical centrifugal pump.

The application discloses a composite double-suction fire pump impeller for low cavitation, which comprises an inlet impeller 2, a splitter impeller 3 and a double-suction impeller 4 which are sequentially arranged on a pump shaft 1. The multiple impeller composite structure effectively improves the flow state, and the impellers complement each other to achieve certain synergistic effect on the flow path. The blade inlet angle of the inlet blade 21 is beta1, the blade inlet angle of the splitter blade 31 is beta2, and the blade inlet angle of the double-suction blade 41 is beta3, wherein (a beta1 + b beta2) / (b beta2 + c beta3) = 0.6-0.85, a is the number of the inlet blades 21, b is the number of the splitter blades 31, and c is the number of the double-suction blades 41. Compared with the prior art, the application optimizes the inlet angle of the blades, modifies the composite impeller structure, significantly improves the flow state, reduces the required net positive suction head of the pump, and effectively reduces the noise and vibration.

The invention discloses a method and a system for detecting the net positive suction head of an electronic water pump for a vehicle, and the method comprises the steps: placing a detected electronic water pump in a detection space of which the internal temperature can be adjusted, and connecting the detected electronic water pump with a water storage tank through a circulation test loop; the circulation test loop can detect the inlet side pressure and the outlet side pressure of the vehicle electronic water pump, control and detect the flow and the temperature of a liquid medium, carry out net positive suction head detection on the detected electronic water pump under each working condition, automatically compare and control the vacuumizing rate and the flow in the test process, collect corresponding net positive suction head data, and carry out automatic detection on the net positive suction head. And finally calculating to obtain the net positive suction head. Manual intervention is reduced as much as possible, the influence of the liquid medium temperature and the environment temperature on the electronic water pump net positive suction head test is fully considered, and the accuracy of the test result can be improved.

This utility model relates to a vertical pipeline centrifugal pump, including a drive source, a pump body, a shaft system, an impeller, and a sealing component. The drive source has an output shaft; the pump body is connected to the drive source and has a suction channel; the shaft system is mounted on the output shaft; the impeller is mounted in the pump body, and the end of the shaft system facing away from the drive source is connected to the impeller; the sealing component is located at the mating point between the shaft system and the pump body; a streamlined guide boss is provided in the area of ​​the suction channel of the pump body near the impeller inlet, and the guide boss gradually contracts along the liquid flow direction; different areas of the pump body have differentiated wall thicknesses, and reinforcing ribs are provided in the areas of concentrated stress on the pump body, with the reinforcing ribs integrally formed with the pump body. This utility model guides the liquid flow evenly into the impeller through the streamlined guide boss in the suction channel, reducing eddies and low-pressure areas, thus reducing the net positive suction head (NPSH) and extending the impeller life; the differentiated wall thickness adapts to the stress in different areas, and the reinforcing ribs can disperse stress and solve the problem of deformation and cracking.

This invention provides a method, apparatus, electronic device, and storage medium for optimizing the operation scheme of a water injection system. The method includes: determining the operation scheme of the water injection system to be optimized; determining the net positive suction head (NPSH) curve of each pump in the water injection system based on the fluid parameters of the fluid in each pump; determining the economic indicators of the water injection system based on the head performance curve of each pump and the fluid parameters; and optimizing the operation scheme of the water injection system to be optimized based on the economic indicators and the NPSH curve to obtain the optimal operation scheme of the water injection system. The optimal operation scheme obtained thereby enables the water injection system to operate in a non-cavitation or low-cavitation range while maintaining energy-saving conditions. This overcomes the shortcomings of traditional schemes where frequency conversion control of pump output cannot avoid the cavitation phenomenon of pumps in the water injection system, resulting in excessively high operation and maintenance costs. This achieves the maximum reduction in operation and maintenance costs.

The utility model relates to an oval arc-shaped water pump water inlet flow guide piece arrangement structure which comprises a water pump, an oval arc-shaped horn mouth, a flow guide cone, four streamline-shaped flow guide piers, a water absorption room bottom plate and a water washing room side wall. The four streamline-shaped flow guide piers are evenly distributed between the oval arc-shaped horn mouth and the water absorption room bottom plate in the horizontal circumferential direction. The axial direction of the streamline-shaped flow guide pier points to the center of the water pump, a flow guide cone is arranged between the oval arc-shaped horn mouth and a bottom plate of the water suction chamber, and the plane projection of the center of the flow guide cone and the plane projection of the center of the water pump coincide. The water inlet flow velocity of the horn mouth is uniformly and progressively increased; four streamline-shaped flow guide piers are arranged on the symmetrical center line of the cone, so that the rotation of water flow in a limited space of the water suction pool during the operation of the water pump can be reduced; the water pump must be reduced in net positive suction head and good in anti-cavitation performance; the water pump is more stable in operation and smaller in vibration, and after practical engineering application, the maximum amplitude value of each part of the water pump is actually measured to be only 0.016 mm.