Guo Chang

Bio: Guo Chang is an academic researcher from Qilu University of Technology. The author has contributed to research in topics: Noise & Centrifugal pump. The author has an hindex of 2, co-authored 3 publications receiving 5 citations.

Measuring method of flow noises of centrifugal pump

Abstract: The invention discloses a measuring method of the flow noises of a centrifugal pump. The method includes the following steps that: (1) a measurement system is established; (2) a noise analyzer and a computer are switched on, noise analysis software is switched on, and debugging is completed; (3) a check valve is opened, an electromagnetic flowmeter is turned on so as to monitoring the flow of a system in real time; (4) the frequency of a frequency converter under an rated operating condition is adjusted, wherein the frequency is corresponding to the rated rotation speed of the centrifugal pump; (5) the centrifugal pump is switched on, and a flow adjustment valve is opened to a full degree; (6) after the system is stabilized, the flow of the system is recorded through the electromagnetic flowmeter, and pressure data obtained by inlet and outlet pressure measuring points are collected and transmitted to the computer through a pressure sensor; (7) noise data collected by inlet and outlet hydrophones are recorded and transmitted to the computer through the noise analyzer; and (8) noise data collected by noise collection devices which are arranged along a circumferential direction are recorded and transmitted to the computer through the noise analyzer.

Centrifugal pump flow noise measurement platform

Abstract: The invention discloses a centrifugal pump flow noise measurement platform The platform comprises a sound insulation room and a sound insulation water box A centrifugal pump bench rack is installed in the sound insulation room A centrifugal pump to be tested is arranged on the centrifugal pump bench rack The centrifugal pump is connected to a motor arranged outside the sound insulation room through a coupling A speed of the motor is controlled by a frequency converter An outlet of the centrifugal pump is connected to the sound insulation water box through an outlet pipeline, and an inlet is connected to the sound insulation water box through an inlet pipeline The outlet pipeline is provided with a flow control valve and a flowmeter The inlet pipeline is provided with a blow-down valve and a check valve A plurality of noise acquisition apparatuses are arranged along a circumference direction of a periphery of the centrifugal pump The noise acquisition apparatuses are connected to a noise analyzer The noise analyzer is connected to a computer

Pump unit typical health status monitoring device and method based on Internet of Things

Abstract: The invention discloses a pump unit typical health status monitoring device and method based on Internet of Things, and belongs to the technical field of intelligent diagnosis of fluid machinery Internet of Things. The pump unit typical health status monitoring device is arranged to be an erecting pump unit platform. Signal collecting sensors are arranged on the pump unit to form an Internet of Things sensing layer which is used as a collection module of data transmission, and forms an Internet of Things network layer with communication protocol; and a field monitoring platform forms an Internet of Things application layer by a touch screen/PC and compiled upper computer software. Functions performance testing, signal processing, fault diagnosing, health evaluating, database managing and remote monitoring and real time monitoring of the pump unit are achieved. Integration, automation and intellectualization of the system are high; predicative maintenance is achieved; occurrence of major accidents and economic loss are avoided, alleviated and reduced; optimal management of pump unit operation is facilitated; benefit level is improved; and pump unit overhauling and maintenance basisis provided.

Numerical simulation of structure-borne noise in a T-shaped tee considering fluid-structure interaction

Abstract: In order to research the structure-borne noise characteristics of a T-shaped tee considering fluid-structure interaction (FSI), the Large Eddy Simulation (LES) and acoustic Finite Element Methods (FEM) were used to simulate the flow field and structure-borne noise related to T-shaped tees under different inlet and outlet combinations. The results show that the frequency domain sound pressure level (SPL) distribution under various inlet flow velocities is stable, the structure-borne noise of the T-shaped tee is a high-frequency noise, and the SPL curves provide a peak distribution. Meanwhile, the distribution characteristics of the structure-borne noise in the frequency domain follows similar trends under different inlet flow velocities. Additionally, the structure-borne noise won't produce the mechanical resonance of the system. When the inlet velocity increases from 1 m/s to 3 m/s, the total sound pressure level (TSPL) increases from 83.71 dB to 98.18 dB, a relative increase of 17.3%. In addition, the frequency domain distributions of the SPL under various inlet and outlet combinations are basically similar. The TSPL of four inlet and outlet combinations for the structure-borne noise are III, IV, II, and I in descending order. When the inlet flow velocity is 1 m/s, 2 m/s, and 3 m/s, in the case of combination I, the TSPL of the structure-borne noise decreases by 6.28 dB, 5.59 dB, and 6.39 dB, in contrast to the combination III, respectively. This study provides the guidance for the noise control and structural optimization design of a T-shaped tee considering the FSI.

Sound attenuator used for pump noise test

Abstract: The invention discloses a sound attenuator used for a pump noise test. The sound attenuator comprises an outer box body, an inner box body disposed inside the outer box body, a total inlet pipeline, aliquid outlet pipeline, a first gas outlet and a second gas outlet, the main inlet pipeline passes through the outer box body, the inner box body and a muffler in sequence, and the liquid outlet pipeline sequentially penetrates the inner box body and the outer body, the inner box body is provided with the first gas outlet, and the second gas outlet is arranged on the outer box body. The sound attenuator used for the pump noise test is suitable for the noise test of a water pump, an oil pump and an air pump, and the noise generated by the fluid during a whole test process is greatly reduced under the action of the sound attenuator, so that the background noise of the pump noise test is greatly reduced. Therefore, the sound attenuator provides an ideal sound field for noise testing of the water pumps, the air pumps and the oil pumps.

Numerical simulation of aerodynamic noise for the two-stage adjustable-blade axial-flow fan

Abstract: In this paper, a three-dimensional calculation model of a two-stage adjustable-blade axial-flow fan is established and verified by grid independence and numerical accuracy. The pressure distribution and sound power level distribution characteristics of the blade surface are explored with variable blade installation angles. Based on the Q-criterion, the study reveals the spatial distribution of the channel and trailing edge shedding and channel vortexes in the flow field. Then, the evolution laws of the fan's aerodynamic noise sound pressure level are also investigated, and its frequency domain characteristics with variable blade installation angles are obtained. The results show that when the rotor blade installation angle is -5{degree sign}, the front-guide vane matches the installation angle of the first-stage impeller. The upper limit of sound power level is the smallest with variable blade installation angles, which is 123.56 dB. Meanwhile, the number and size of vortex structures in the front-guide vane area are the smallest, and the turbulent flow in the flow field is moderate. As the moving blade installation angle is deflected from -10{degree sign} to 10{degree sign}, the total sound pressure level of aerodynamic noise at each component of the fan first decreases and then increases. The minimum value is 121.40 dB and 128.40 dB at the inlet and outlet when the blade installation angle is -5{degree sign}. In addition, the number of eddies periodically shed in the fan flow field is the least. This research can supply technical support for the noise reduction of the two-stage adjustable blade axial fan.

Method for evaluating acoustic characteristics of water pumps and pipelines in reverberation pools

Abstract: The invention belongs to the field of acoustic measurement, and particularly relates to a method for evaluating acoustic characteristics of water pumps and pipelines in reverberation pools. The methodcomprises the following steps of: selecting a reverberation pool with a suitable size, and calculating a cutoff frequency Fs of the reverberation pool according to physical characteristics of the reverberation pool; measuring a reverberation time T60 of the reverberation pool by using an interrupted sound source method; mounting a to-be-measured pipeline system, vertically inserting the water outlet end of the pipeline into the reverberation pool, and injecting water; measuring a space averaged sound pressure level (SPL) of a water pump and pipeline system by using a space averaging method; and deriving a radiative sound powder level (SWL) of the sound source according to the measured space averaged sound pressure level (SPL) in a reverberation sound field. The method n is simple, easy tooperate, obvious in experimental effect is obvious and easy to evaluate, and does not need to mount measurement hydrophones in pipelines, so that the hydrophones are not affected by the turbulence pulsating pressure; compared with the small chamber method, the method is capable of obtaining real values of radiative sound power of pump and pipeline systems; and the method is capable of carrying out measurement in common reverberation pools, so that the measurement cost is extremely low.