JRN镍基渗层管热网加热器等产品

<正> 济南市压力容器厂位于济南市西外环路(段店南路),始建于1979年,企业规模为中型一档企业,企业性质为股份合作制。 济南市压力容器厂于1985年取得一、二类压力容器的制造资格证书,并于1993年5月取得了一、二类压力容器设计资格证书。1998年10月取得了三类压力容器设计资格证书。

Application of neural network in heating network leakage fault diagnosis

In order to investigate the leak detection strategy of a heating network,a space-based simulation mathematical model for the heating network under leakage conditions is built by graph theory.The pressure changes of all the nodes in the heating network are obtained from node leak and pipe leak conditions.Then,a leakage diagnosis system based on the back propagation（BP）neural network is established.This diagnosis system can predict the leakage pipe by collecting the pressure change data of the monitoring points,which can preliminary estimate the leak location.The usefulness of this system is proved by an example.The experimental results show that the forecast accuracy by this diagnosis system can reach 100%.

Fabrication and thermal performance of grooved-sintered wick heat pipe

Some novel grooved-sintered composite wick heat pipes(GSHP) were developed for the electronic device cooling.The grooved-sintered wicks of GSHP were fabricated by the processes of oil-filled high-speed spin forming and solid state sintering.The wick could be divided into two parts for liquid capillary pumping flow:groove sintered zone and uniform sintered zone.Both of the thermal resistance network model and the maximum heat transfer capability model of GSHP were built.Compared with the theoretical values,the heat transfer limit and thermal resistance of GSHP were measured from three aspects:copper powder size,wick thickness and number of micro grooves.The results show that the wick thickness has the greatest effect on the thermal resistance of GSHP while the copper powder size has the most important influence on the heat transfer limit.Given certain copper powder size and wick thickness,the thermal resistance of GSHP can be the lowest when micro-groove number is about 55.

Synthesis of Heat Exchanger Network Considering Multipass Exchangers

Many methods have been proposed for synthesis of heat exchanger networks in recent years, most of which consider single pass exchangers. In this study some evolutionary rules have been proposed for synthesis of multipass exchanger networks. The method is based on the heuristic that optimal networks should feature maximum energy recovery and have the minimum number of shells. The effectiveness of the developed evolutionary rules is demonstrated through some literature examples.

Indirect heat integration across plants using hot water circles

Total site heat integration(TSHI) provides more opportunities for energy saving in industry clusters. Some design methods including direct integration using process streams and indirect integration using intermediate-fluid circuits, i.e., steam, dowtherms and hot water, have been proposed during last few decades. Indirect heat integration is preferred when the heat sources and sinks are separated in independent plants with rather long distance. This improves energy efficiency by adaption of intermediate fluid circle which acts as a utility provider for plants in a symbiotic network. However, there are some significant factors ignored in conventional TSHI, i.e. the investment of pipeline, cost of pumping and heat loss. These factors simultaneously determine the possibility and performance of heat integration. This work presents a new methodology for indirect heat integration in low temperature range using hot water circuit as intermediate-fluid medium. The new methodology enables the targeting of indirect heat integration across plants considering the factors mentioned earlier. An MINLP model with economic objective is established and solved. The optimization results give the mass flow rate of intermediate-fluid, diameter of pipeline, the temperature of the circuits and the matches of heat exchanger networks(HENS) automatically. Finally, the application of this proposed methodology is illustrated with a case study.

Numerical analysis on heat transfer of laser diode module by equivalent electrical network method

Because it is complex and inconvenient to use the common temperature field calculating method and experiment method, for arialyzing heat transfer properties of laser diode module （LDM）, an equivalent electrical network method is presented in this paper. Simulation results show that the temperature stability is closely related to ambient temperature, heat sink, LDM current and TEC current. Ambient temperature and TEC controller are the dominant terms effecting on temperature control in practice,

Determining heating pipe temperature in greenhouse using proportional integral plus feedforward control and radial basic function neural-networks

Proportional integral plus feedforward (PI+FF) control was proposed for identifying the pipe temperature in hot water heating greenhouse. To get satisfying control result, ten coefficients must be adjusted properly. The data for training and testing the radial basic function (RBF) neural-networks model of greenhouse were collected in a 1028 m2 multi-span glasshouse. Based on this model, a method of coefficients adjustment is described in this article.

Thermal analysis of laser diode module by an equivalent electrical network method

An equivalent electrical network method is presented in this paper to analyze the cooling characteristics of a laser diode module (LDM).And a modified equivalent model of a thermoelectric cooler (TEC) with an adjunctive thermal resistance and a contact resistance is proposed.The performance of a commercial TEC has been simulated.The thermal analysis of a LDM incorporated with a TEC has been performed by using an equivalent circuit model of the LDM.In the analysis the change of LD current,TEC current,and the ambient temperature are all considered.It shows that the equivalent circuit approach is an effective tool for the qualitative analysis of TEC and LDM.

Heat Transfer and Flow Analysis in Loop Heat Pipe with Multiple Evaporators Using Network Model

Thermal performance of a loop heat pipe with two evaporators and two condensers was examined using a lumped network model analysis. Thermosyphon-type vertical loop heat pipe and capillary-pump-type horizontal loop heat pipe were calculated by examining the change of heating rate of two evaporators. Calculation results showed that the vapor and liquid flow rates in the loop heat pipe and the thermal conductance of the heat pipe changed significantly depending on the distribution ratio of the heating rate of the multiple evaporators. The thermal performance of the vertical loop heat pipe with two evaporators was also examined and experimental results of flow direction and thermal conductance of the heat pipe agreed with the analytical results. The lumped network model analysis is therefore considered accurate and preferable for the practical design of a loop heat pipe with multiple evaporators.

Probability of Failure Assessment in District Heating Network

The aim of this paper is to present works performed in HTC （Heat-Tech Center）, Research ＆ Development Centre of Veolia Group located in Warsaw regarding assessment of probability of failure in DHN （district heating network）. This work is a part of a project dedicated to develop a software which objective is to increase reliability of DHN. The research methods consisted of three approaches. First, using database of failures which happened in Warsaw DHN and repairing protocols from past 10 years, a statistics approach was applied to perform first analysis. The result was that pipelines with nominal diameter DN （nominal diameter） ≤ 150 had higher failure rate per km, than pipelines with DN 〉 150. The next step of research was to study influence of internal （corrosion caused by heat carrier, quality of materials） and external （stray currents） factor in order to assess its individual influence on failure rate of pipe and explain reasons of differences in failure rate. To end a FMEA （failure mode and＇effects analysis） will aim to identify the main failures modes appearing on DHN, to estimate the main causes of these failures and to propose the best solutions regarding the causes, the costs and the means available.

Neural Network Model for Boiling Heat Transfer of R22 and Its Alternative Refrigerants inside Horizontal Smooth Tubes

Accurate prediction of refrigerant boiling heat transfer coefficients is important for the design of evaporators. The generalized correlations have different forms, and could not provide satisfactory results for R22 and its alternative refrigerants R134a, R407C and R410A. This study proposes to use artificial neural network (ANNs) as a generalized correlation model, selects the input parameters of ANNs on the basis of the dimensionless parameter groups of existing correlations, and correlates the in-tube boiling heat transfer coefficients of the above four refrigerants. The results show that the ANNs model with the input and output based on the Liu-Winterton correlation has the best result. The root-mean-square deviations in training and test are 15.5% and 20.2% respectively, and approximately 85% of the deviations are within ±20%, which is much better than that of the existing generalized correlations.

Prediction of Heat Transfer Rates for Shell-and-Tube Heat Exchangers by Artificial Neural Networks Approach

This work used artificial neural network(ANN)to predict the heat transfer rates of shell-and-tube heatexchangers with segmental baffles or continuous helical baffles,based on limited experimental data.The BackPropagation (BP) algorithm was used in training the networks.Different network configurations were alsostudied.The deviation between the predicted results and experimental data was less than 2%.Comparison withcorrelation for prediction shows ANN superiority.It is recommended that ANN can be easily used to predict theperformances of thermal systems in engineering applications,especially to model heat exchangers for heattransfer analysis.