某型风机转子临界转速计算和对中研究

采用应变能法对某型风机转子进行了模型建立和简化。利用有限元法,对该型轴流风机转子的临界转速和不平衡响应进行了理论分析,根据相关标准,对转子的安全性进行了考核和评估。并对轴系的挠度和扬度进行了计算。结合理论分析和测试结果对风机的标高进行了现场调整,最终取得了良好的效果,并且振动满足设计要求。     

组装集箱制造工艺优化

在原有的组装集箱制造工艺的基础上,又经过多个项目的生产实践,通过对组装集箱生产制造过程中出现的问题进行分析和总结,对其制造工艺进行了一些改进和优化,主要体现在对组装集箱装配工装的抗热处理变形能力和不锈钢拉撑定位板进行了改进,对管端的修正余量和管端复加工刀具进行了优化,对相应的部分制造工艺进行了调整。     

储能材料(介质)导热性能研究Ⅰ.高分子材料导热系数研究(平板法)

为了能对固体蓄能材料和液态蓄冷介质的导热系数进行测量，搭建了一座平板导热实验台，对普通有机玻璃和蒸馏水进行了测试以校核精度，对几种新型有机高分子材料的导热系数进行了测试并进行了讨论。     

电机系统能效现状和节能潜力分析方法综述

文章对我国电机系统的能耗状况、我国电动机、拖动设备和系统的能效状况与发达国家的差距进行了阐述和分析,对欧美和我国采取的推进电机系统节能的措施和项目进行了介绍,在此基础上对电机系统的节能分析方法和主要的节能技术进行了论述。最后,对上海实施的有代表性的节能改造项目情况进行了介绍。     

MDI地震属性技术在东濮凹陷HZJ地区储层预测中的应用

简要介绍了MDI地震属性技术在进行储层预测时的研究思路，对HZJ地区井信息和三个砂层组地震属性信息进行了提取和优选．进行了砂岩厚度和含油气性的预测，同时对预测的不确定性和风险进行了分析。     

摆线转子泵的设计计算

从摆线泵啮合和摆线的定义出发对摆线啮合的参数和计算公式进行了介绍,对较为复杂的摆线内转子的型线方程进行了推导和说明,给出了摆线泵流量的精确计算公式,并对设计中需注意的问题进行了说明。最后用一个摆线转子泵计算的实例对计算公式进行验证并绘出了摆线转子的图形。     

太阳能电热联用系统研究进展

首先对太阳能电热联用系统的基本组成形式进行了简要介绍,并对不同的电热联用集热器、热能利用 方式进行了对比分析,接着对电热联用的研究方法和发展现状进行了详细说明,并列举了一些电热联用产品和 示范工程,最后指出了电热联用发展中应解决的问题,并对其发展前景进行了展望。     

船舶内燃机弹性支承的应用与进展

对弹性支承在船舶内燃机上的应用及相关理论进行了阐述,对采用弹性支承时机组的纵向位移和垂向跳动两大问题作了特别的探讨,指出了注意事项和解决办法;为满足对振动和噪声的特殊要求,对双层隔振结构进行了介绍,并以MTU公司根据不同的具体要求提供的若干种不同结构为例进行了讨论;最后对作为弹性支承最新发展的主动式支承进行了讨论,介绍...     

薄壁油冷活塞三维有限元计算及强度分析

采用三维有限元法对某新设计的船用柴油机的整体薄壁球墨铸铁活塞的变形和应力场进行了计算并在此基础上对该活塞的疲劳强度和热变形进行了校核，同时还对这种薄壁油冷活塞的变形和应力分布特点进行了分析，由此得出了具有参考价值的设计要点。     

DF11型机车柴油机隔振系统改进

对戚墅堰机车车辆厂DF11型机车柴油机隔振系统进行了改进研究,对改进前原有隔振系统进行了测试,提出了隔振器改进设计的思路和方法,并对改装6WN-8500型隔振器后进行了装车测试,对结果进行分析比较,证实了隔振器改进项目是成功的。     

Salt gradient stabilized solar pond collector

This paper presents a theoretical analysis of a salt gradient solar pond as a steady state flat plate solar energy collector. We explicitly take into account the convective heat and mass flux through the pond surface and evaluate the temperature and heat fluxes at various levels in the pond by solving the Fourier heat conduction equation with internal heat generation resulting from the absorption of solar radiation as it passes through the pond water. These evaluations, in combination with energy balance considerations, enable the derivation of the expressions for solar pond efficiency of heat collection as well as the efficiency of heat removal. The efficiency expressions are Hottel-Whillier-Bliss type, prevalent for flat plate collectors. Numerical computations are made to investigate the optimization of geometrical and operational parameters of the solar pond. For given atmospheric air temperature, solar insolation and heat collection temperature, there is an optimum thickness of nonconvective zone for which the heat collection efficiency is maximum. The heat removal factor is also similar to that of a flat plate collector and the maximum efficiency of heat removal depends on both the flow rate and the temperature in the nonconvective zone.     

Field testing on nonsalt solar ponds

A new type of nonsalt solar pond was investigated by field testing. The roof of the solar pond was formed using a transparent double film. Three kinds of tests were carried out under the following conditions: (1) insulating pellets were packed between the layers of the transparent double film of the roof at sunset; (2) the water surface of the pond was insulated using only the two transparent films; (3) the water surface of the pond was covered by the double film with the top surface blackened on which solar energy can be collected, while pond water was circulated using a solar cell powered submerged water pump. The warm water stored in the solar pond by the above methods was utilized as a heat source for a gas engine powered heat pump used to heat a greenhouse. In this report, the results of the field tests on the above solar ponds and greenhouse heating system are discussed. Also the utility of a combination plant using a solar pond and underground borehole storage system is evaluated.Important conclusions on performance are as follows: (1) collection efficiencies of these solar ponds become 9–54% corresponding to the weather conditions and pond temperatures; (2) maximum temperature of the pond water under weather conditions at Osaka is about 80°C; (3) the solar pond can be effectively utilized for heating a greenhouse; (4) the combination plant using the solar pond and the underground storage layer can store heat of 1119 MJ m⁻² yr⁻¹.     

Dependence of ground heat loss upon solar pond size and perimeter insulation calculated and experimental results

Ground heat losses from solar ponds are modelled numerically for various perimeter insulation strategies and several solar pond sizes. The numerical simulations are steady state calculations of heat loss from a circular or square pond to a heat sink at the outer boundaries of an earth volume that surrounds the pond on the bottom and sides. Simulation results indicate that insulation on top of the ground around the pond perimeter is rather ineffective in reducing heat loss, and that uninsulated sloping side walls are slightly more effective than insulated vertical side walls, except for very small ponds. The numerical results are used to derive coefficients for a semi-empirical equation describing ground heat loss as a function of pond area, pond perimeter and insulation strategy. Experimental results for ground heat loss and energy balance in the 400 m² solar pond at the Ohio State University are reported. Analysis of this data, along with data on solar energy input, heat gain by the pond, heat loss through the gradient zone, and heat extraction from the pond yields a good energy balance. Numerical simulation of ground heat loss from this pond shows good agreement with the results obtained from pond measurements. Loss turns out to be large because of unexpectedly high values of earth thermal conductivity in the region.     

Spectral calculation of the thermal performance of a solar pond and comparison of the results with experiments

This paper deals with a method and the result of the spectroscopic calculation on heat balance of a salt-gradient solar pond under the conditions of spectral solar radiation. Furthermore, reflection of the ray incident upon the surface of the pond water, refraction of the rays within the salt-water layer and diffusion of salt in the pond water are considered. On the other hand, in order to make a clear mechanism of the heat collection and heat storage of the solar pond, we conducted an indoor experiment and a numerical analysis on a small scale model of the salt-gradient solar pond with 2 m² surface area and 1.6 m depth, under the incident rays from a Xe-lamp solar simulator. According to the above experimental analysis, we made a simulation model of thermal performance for a solar pond and carried out the calculation from the heat balance. We found that the simulation calculations correspond well to the experimental results, so that our thermal simulation model and method might be correct. We also did the thermal calculation by changing the incident rays from a Xe-lamp into natural ray (Moon’s spectrum) and Halogen lamp. As a result, it was found that the temperature distributions in the solar pond were notably different due to spectral characteristics of the incident ray. Therefore, the spectroscopic consideration for thermal performance of any solar pond is necessary to obtain a correct solution under the spectral incidence with special wavelength distributions.     

Thermal analysis of three zone solar pond

This paper presents a periodic analysis of a three zone solar pond as a solar energy collector and long term storage system. We explicitly take into account the convective heat and mass flux through the pond surface and evaluate the temperature and heat fluxes at various levels in the pond during its year round operation by solving the time dependent Fourier heat conduction equation with internal heat generation resulting from the absorption of solar radiation in the pond water. Eventually, an expression, for the transient rate at which heat can be retrieved from the solar pond to keep the temperature of the zone of heat extraction as constant, is derived. Heat retrieval efficiencies of 40.0 per cent, 32.1 per cent, 28.3 per cent and 25.5 per cent are predicted at collection temperatures of 40, 60, 80 and 100°C, respectively. the retrieved heat flux exhibits a phase difference of about 30 to 45 days with the incident solar flux; the load levelling in the retrieved heat flux improves as the thickness of the non-convective zone increases. the efficiency of the solar pond system for conversion of solar energy into mechanical work is also studied. This efficiency is found to increase with collection temperature and it tends to level around 5 per cent at collection temperatures about 90°C.     

太阳池的研究与应用

自从1902年Kalecsinsky首次发现了天然太阳池现象以后，经过长期的研究和发展，太阳池技术已被广泛应用于发电、取暖、海水淡化．矿物加工等领域，太阳池成为近期内进行大规模太阳能热利用的最有前景的低温热源装置。主要综述了太阳池的集热原理及建造方法、太阳池中热量的贮存及提取方式、太阳池的应用以及研究动向等，并指出目前我国太阳池技术还处于实验研究的阶段，而我国具有丰富的太阳能和盐资源，大力开发太阳池技术将为发展地方经济起到重要的作用。     

Thermal behavior of a small salinity-gradient solar pond with wall shading effect

The thermal behavior of a small-scale salinity-gradient solar pond has been studied in this paper. The model of heat conduction equation for the non-convective zone has been solved numerically with the boundary conditions of the upper and lower convective zones. The variation of the solar radiation, during a year, and its attenuation in the depth of the pond has been discussed. The wall shading area for a vertical wall square pond has been elaborated and its effect on the reduction of the sunny area has been included in the model. The temperature variation of the storage zone has been calculated theoretically and compared with the experimental results. The sensitivity analysis demonstrates the importance of the side and bottom insulation and the thickness of the non-convective zone, as well as the wall shading effect on the performance of the pond. The application of several loading patterns gives an overall efficiency of 10% for the small pond.     

A solar pond-assisted heat pump for greenhouses

A solar pond for annual cycle solar energy collection and storage was studied at The Ohio Agricultural Research and Development Center (OARDC), Wooster. It has been used as a thermal energy source for greenhouse heating. A brine-source electric-power-driven heat pump was incorporated into the heat extraction system. Initial results of the field studies indicated that the combined system improved the effectiveness of both the heat pump and the solar pond by enabling a larger temperature cycle within the solar pond.

To study the operation of such a system, a computer simulation model for the heating system was developed. The results of simulations were used to establish a relationship between the system performance and the present design and for sizing the solar energy collection and storage system. Also, the effect of a polystyrene pellet nighttime insulation for the greenhouse was simulated. Increasing the surface area of the OARDC pond was found to be less effective than changing its depth. Thr results showed that a 5 m deep pond with 1.0 m gradient zone significantly improved the overall performance of the system when used as a heat source for a heat pump. Based on the detailed experimental and computer simulation performance analysis, the solar pond-assisted heat pump system has the potential of improved performance compared with convential air source heat pumps.     

Modeling the performance of a solar pond as a source of thermal energy

The use of solar ponds is becoming more attractive in today's energy scene. A major advantage of solar ponds over other collectors is the ability to store thermal energy for long periods of time. The solar pond comprises a hydraulic system subject to processes of heat and mass transfer. The design of this system and the related equipment requires a thorough knowledge of the pond heating-up process and expected thermohaline structure within the pond. The current study considers that convection currents in the pond are inhibited by the salinity distribution, and applies a finite difference implicit model in order to investigate the interaction among physical variables represented by various dimensionless parameters. Variables which are included in the analysis comprise the solar radiation input and absorption as it passes through the pond; diffusion and dispersion of heat within the pond; absorption of heat at the bottom of the pond; and withdrawal of heat from layers within the pond. The physical variables generate 3 dimensionless variables associated with the pond's heating-up process. A 4 dimensionless variable is associated with the heat utilization. The analysis represented in this paper concerns the interaction between these dimensionless parameters and its implications.     

Effects of porous media on thermal and salt diffusion of solar pond

Laboratory and field experiments were carried out along with numerical simulations in this paper to study the effects of porous media on thermal and salt diffusion of the solar ponds. From our laboratory experiments simulating heat transfer inside a solar pond, it is shown that the addition of porous media to the bottom of a solar pond could help enhance its heat insulation effect. The experiment on salt diffusion indicates that the upward diffusion of the salt is slowed down when the porous media are added, which helps maintain the salt gradient. Our field experiments on two small-scaled solar ponds indicate that when porous media are added, the temperature in the lower convective zone (LCZ) of the solar pond is increased. It is also found that the increase in turbidity is repressed by porous media during the replenishment of the salt to the LCZ. Thermal diffusivities and conductivities of brine layers with porous media such as pebble and slag were also respectively measured in this paper based on the unsteady heat conducting principles of a semi-infinite body. These measured thermal properties were then used in our numerical simulations on the effect of porous media on thermal performance of a solar pond. Our simulation results show that brine layer with porous media plays more positive role in heat insulation effect when thermal conductivity of the ground is big. On the other hand, when the ground has a very small thermal conductivity, the performance of solar pond might be deteriorated and total heat storage quantity of solar pond might be reduced by brine layer with porous media.