燃气锅炉烟风系统振动和噪声的分析及优化设计

锅炉烟、风系统的振动现象极为普遍,针对某热源厂“煤改气”二期工程装机的116 MW燃气热水锅炉烟、风系统和锅炉本体高负荷运行中产生振动和噪声等问题进行分析,并提出相应的合理优化设计方案。按照优化设计方案实施改造以后,通过2020—2021和2021—2022两个采暖季的实际运行效果来看,燃气锅炉高负荷运行时的振动和噪声明显较小,达到了预期改造效果。

消除空气预热器风系统振动的措施

消除空气预热器风系统振动的措施唐际木（广西桂林电厂桂林５４１００３）１概况桂林电厂１号炉系上海锅炉厂生产的６５—３．８２—４５０型机播链条炉，１９５９年１２月建成投产，１９６９年改为钢球磨煤直吹式直流煤粉燃烧的固态排渣炉。为改善燃烧，１９９０年７月改...

Feasibility of monitoring a mine fan by using interaction of vibrator system

The impeller of turbo machinery is a typical nonlinear multi-oscillator system.The vibration of each module is coupling, including fluid-solid coupling of the blade.The subject of our investigation was a KDF-5 mine fan for which we analyzed air vibration signals and axial vibration signals by using correlation dimension analysis under five variable working conditions.The results indicate that their correlation dimension curves show a uniform trend.That is to say, the characteristics of the variation signals of the integral structure are correlated and mutually embodied.It proves that it is possible to monitor the working state of a mine fan by coupling the vibration signals and air vibration signals for these are more sensitive in representing the status of the impeller system.

Effect of cross-wind on spatial vibration responses of train and track system

By taking cross-wind forces acting on trains into consideration, a dynamic analysis method of the cross-wind and high-speed train and slab track system was proposed on the basis of the analysis theory of spatial vibration of high-speed train and slab track system. The corresponding computer program was written by FORTRAN language. The dynamic responses of the high-speed train and slab track under cross-wind action were calculated. Meanwhile, the effects of the cross-wind on the dynamic responses of the system were also analyzed. The results show that the cross-wind has a significant influence on the lateral and vertical displacement responses of the car body, load reduction factor and overturning factor. For example, the maximum lateral displacement responses of the car body of the first trailer with and without cross-wind forces are 32.10 and 1.60 mm, respectively. The maximum vertical displacement responses of the car body of the first trailer with and without cross-wind forces are 6.60 and 3.29 mm, respectively. The maximum wheel load reduction factors of the first trailer with and without cross-wind forces are 0.43 and 0.22, respectively. The maximum overturning factors of the first trailer with and without cross-wind forces are 0.28 and 0.08, respectively. The cross-wind affects the derailment factor and lateral Sperling factor of the moving train to a certain extent. However, the lateral and vertical displacement responses of rails with the crnss-wind are almost the same as those without the cross-wind. The method presented and the corresponding computer program can be used to calculate the interaction between trains and track in cross-wind.

Effects of fundamental factors on coupled vibration of wind-rail vehicle-bridge system for long-span cable-stayed bridge

In a wind-vehicle-bridge(WVB) system,there are various interactions among wind,vehicle and bridge.The mechanism for coupling vibration of wind-vehicle-bridge systems is explored to demonstrate the effects of fundamental factors,such as mean wind,fluctuating wind,buffeting,rail irregularities,light rail vehicle vibration and bridge stiffness.A long cable-stayed bridge which carries light rail traffic is regarded as a numerical example.Firstly,a finite element model is built for the long cable-stayed bridge.The deck can generally be idealized as three-dimensional spine beam while cables are modeled as truss elements.Vehicles are modeled as mass-spring-damper systems.Rail irregularities and wind fluctuation are simulated in time domain by spectrum representation method.Then,aerodynamic loads on vehicle and bridge deck are measured by section model wind tunnel tests.Eight vertical and torsional flutter derivatives of bridge deck are identified by weighting ensemble least-square method.Finally,dynamic responses of the WVB system are analyzed in a series of cases.The results show that the accelerations of the vehicle are excited by the fluctuating wind and the track irregularity to a great extent.The transverse forces of wheel axles mainly depend on the track irregularity.The displacements of the bridge are predominantly determined by the mean wind and restricted by its stiffness.And the accelerations of the bridge are enlarged after adding the fluctuating wind.

Safety analysis and control of blasting mining area adjacent to infrastructure

Systematic analysis of influence of blasting vibration on bridges,tunnels,slopes and the mechanical relationships between each other were drawn based on the example of safety argument between blasting mining area and protected objects.The safety argument methods and technological means of controlling dangerous and harmful factors were proposed by the application of principle of risk analysis.And standard control system was established based on controlling the blasting parameters of division of blasting area.

Study of a Dual-sided Multiple Fans System with a Piezoelectric Actuator

A dual-sided multiple fans system with a piezoelectric actuator （＂D-MFPA＂）, which is able to drive eight passive vibrating fans and provide two-directional air flows by using only one piezoelectric actuator, has been investigated in this study. Moreover, two types of the fan designs, viz. magnetic fan （MF） and composite magnetic fan （CMF） were also explored. In the investigation of the MF, the results indicated that the resonance frequency of the D-MFPA increased from 27.6 Hz to 66 Hz as the length of the carbon fiber plate （L） decreased from 55 mm to 35 mm. It also decreased the amplitude of the D-MFPA from 12.4mm to 4.8 mm. For CMF, the results showed that the resonance frequency decreased when the length of the Mylar plate （Et） increased, and the maximum decrease was from 66 Hz to 45 Hz when L= 35 mm and Er= 30 mm. Dimensionless heat convection number （MD_MFPA） was defined to describe and quantify the improvement in the thermal performance. The results showed that the optimal MO-MFPA of the single piezoelectric fan was 1,58 for cooling one heat source. By contrast, under the same power consumption, the D-MFPA not only cooled two heat sources but also displayed better thermal performance.