A pH Model for Calculating the pH Value of Mixed–Acid–Base Equilibria of Overhead Condensing Systems in Crude Distillation

A pH predictive model based on acid–base equilibria and ion equilibria was proposed to calculate the pH value of the overhead condensing system of crude distillation unit. The pH model could be used to predict the appropriate amounts of neutralizers by measuring the Cl-ion concentration of the overhead knockout drum. The pH values of various neutralized streams were estimated by this model. The results showed that the predicted pH values were in good agreement with the experimental ones. The trend of the corrosion inhibition efficiency decreases in the following order: ethylenediamine > N,Ndimethylethanolamine> triethylamine > 3-methoxypropylamine > morpholine. The difficulty in the accurate control of corrosion was solved, and a good instruction was provided for mitigating corrosion in refinery.

NUMERICAL SIMULATION OF WET STEAM CONDENSING FLOW WITH AN EULERIAN/EULERIAN MODEL

Wet steam condensing flow in low-pressure steam turbine leads to efficiencylosses and blade erosions. In order to investigate this problem by numerical approach, anEulerian/Eulerian model has been developed, in which the wet steam is regarded as mixture comprisingtwo coupled systems: the vapor phase and the liquid phase. These two systems are both described byconservation equations. High resolution TVD scheme is employed to capture condensing phenomena inwet steam flow. This model has been validated by numerical simulations of condensing flows in 1D and2D nozzles. Compared with experimental data, a good agreement is observed. This Eulerian/Eulerianmodel can be extended to 3D calculation of condensing flow.

NEW FIXED POINT THEOREMS OF CONDENSING MAPPINGS SATISFYING THE INTERIOR CONDITION IN BANACH SPACES

In this paper, based on a basic result on condensing mappings satisfying the interior condition, some new fixed point theorems of the condensing mappings of this kind are obtained. As a result, the famous Altman＇s theorem, Roth＇s theorem and Petryshyn＇s theorem are extended to condensing mappings satisfying the interior condition.

Study on Airflow Field of Condensing Zone in Compact Spinning System with Perforated Drum

Negative pressure plays a very important role in compact spinning system.To know airflow field and its distribution is helpful to look into the condensing principle of fiber bundle.Therefore,computational fluid dynamics(CFD)software was used to simulate airflow field in this paper.Airflow velocity distributions both in different fiber layers and under different negative pressures were discussed.The results indicate that airflow velocity in upper layer of the fiber bundle is greater than that in lower layer.Airflow velocities in both X and Y axis directions have a positive correlation with negative pressure.It can provide a theoretical base to make high quality compact yarns in productive practice.

Study of steady and unsteady wet steam condensing flows in a turbine stage

Objective To develop the numerical method for the steady and unsteady wet steam condensing flow in turbine stage. Methods An Eulerian/Eulerian numerical model is used to describe the spontaneous condensation flow in the steam turbine. For the steady condensing flow computations, the mixing plane model was used. For the unsteady condensing flow computations, the sliding mesh method was used to simulate the rotor-stator interactions. Results The numerical results showed the obvious differences between non-condensing and condensing flows. The results also showed the unsteadiness effect due to rotor-stator interactions had a deep influence on the formation and growth process of water droplets. Conclusion The numerical methods presented in this paper are valid for the condensing flow in the turbine stage.

FIXED POINT THEOREMS FOR MEIR-KEELER CONDENSING OPERATORS VIA MEASURE OF NONCOMPACTNESS

In this article, we introduce the notion of Meir-Keleer condensing operator in a Banach space, a characterization using L-functions and provide a few generalization of Darbo fixed point theorem. Also, we introduce the concept of a bivariate Meir-Keleer condensing operator and prove some coupled fixed point theorems. As an application, we prove the existence of solutions for a large class of functional integral equations of Volterra type in two variables.

Condensing osteitis of the clavicle in children

AIM: To confirm the rarity of this disorder and then to evaluate the effects of antibiotic treatment alone and assess whether this could produce a complete remission of symptoms in children and adolescents.METHODS: We made a retrospective review of all cases of condensing osteitis of the clavicle in children and adolescents between January 2007 and January 2016. Outpatient and inpatient medical records, with radiographs, magnetic resonance imaging, triphasic bone scan and computed tomography scans were retrospectively reviewed. All the patients underwent biopsy of the affected clavicle and were treated with intra venous(IV) antibiotics followed by oral antibiotics.RESULTS: Seven cases of condensing osteitis of the clavicle were identified. All the patients presented with swelling of the medial end of the clavicle, and 5 out of 7 reported persisting pain. The patients' mean age at presentation was 11.5 years(range 10.5-13). Biopsy confirmed the diagnosis in all cases. All the patients completed the treatment with IV and oral antibiotics. At last follow-up visit none of the patients complained of residual pain; all had a clinically evident reduction in the swelling of the medial end of the affected clavicle. The mean follow-up was 4 years(range 2-7).CONCLUSION: Our findings show that condensing osteitis of the clavicle is a rare condition. Biopsy is needed to confirm diagnosis. The condition should be managed with IV and oral antibiotics. Aggressive surgery should be avoided.

Condensing Heat Recovery of Centrifugal Chiller

To a kind of centrifugal water chiller with R22 and about 1 745 kW of cooling capacity,a heat exchanger was added between the outlet of compressor and original condenser to get part of or all the condensing heat.Condensing heat can be recovered by compound condensing method,which adopts air-cooling model +water-cooling model or water-cooling model +water-cooling model at the condensing side of the system.By exergy analysis and experiment research on compound condensing heat recovery of centrifugal chiller,the results are obtained that the capability of the whole system increases,the energy efficiency ratio(EER)becomes 3.2～5.0 from 2.2～3.4,which implies the EER increases about 1.0～1.5,the exergy efficiency increases about 10%,and the chiller runs more stably after reformation.

Maximal elements and generalized games involving condensing mappings in locally FC-uniform spaces and applications(Ⅰ)

First, the notions of the measure of noncompactness and condensing setvalued mappings are introduced in locally FC-uniform spaces without convexity structure. A new existence theorem of maximal elements of a family of set-valued mappings involving condensing mappings is proved in locally FC-uniform spaces. As applications, some new equilibrium existence theorems of generalized game involving condensing mappings are established in locally FC-uniform spaces. These results improve and generalize some known results in literature to locally FC-uniform spaces. Some further applications of our results to the systems of generalized vector quasi-equilibrium problems will be given in a follow-up paper.

Modeling and numerical analysis of evaporative condensing regenerator

A two-dimensional steady state model was developed and solved numerically to predict the performance of evaporative condensing regenerator.Two-dimensional parameter distributions of air,solution and refrigerant were calculated by the mathematical model.The solution content first increases and then decreases along the solution flow direction.At y/Hr=0.98(where Hr is the height of regenerator),air humidity increases from 1.99% to 2.348% firstly and then decreases.The experimental results were used to validate mathematical model.It is indicated that the simulation results agree with experimental data well.The results not only show that the mathematical model can be used to predict the performance of regenerator,but also has great value in the design and improvement of evaporative condensing regenerator.

Topology Chemical Process Research on the Condensing and Growing Phase Multi Micro Oil Droplets Based on Hydrodynamics

The hydrodynamic research about the droplet condensing of the multi phase liquid state on the surface of the coal glass and water discusses the deepening process of convex shape curve and the formation of S shape, and puts emphasis on describing the diagram formation method of the later. In the induction period the active diagram of the micro droplet is decided by pH value forming as convex shape diagram or S shape diagram. When pH value is above 4.0, the damage of convex shape diagram cannot be recovered, in that case produce S shape activity diagram. When pH value is equal to or above 12.0, the hard surface with alkali liquid state loses adhesion, so that the micro droplet condensing of the multi phase liquid state stops completely. The research result shows that the water cleaning conditions of getting rid of the oil micro droplets can be decided by the pH value.

On Positive Eigenvalues and Positive Fixed Points of Multivalued Condensing Mappings

In this paper,we discuss the calculations of fixed point indexs for multivalued condensing mappings and k-set-contraction mappings,obtain some theorems on the eigenvalues and the fixed points under the suitable conditions. Our conclusions improve and generalize some well-known results.

MAXIMAL ELEMENTS OF CONDENSING PREFERENCE MAPS IN LOCALLY CONVEX HAUSDORFF SPACES

Two existence theorems of maximal elements of condensing preference maps in locally convex Hausdorff spaces are proved which generalize the recent results of Mehta. One of them positively answers the open problem mentioned by Mehta.

Influence of Condensing Temperature on Heat Pump Efficiency

The thermodynamic aspect of a compression type heat pump （HP） is briefly described and special attention is given to investigation of condensing temperature influence on heat pump efficiency in heating mode, expressed by its coefficient of performance （COP）. Heat pumps are usually applied for the purposes of heating and cooling of energy efficient buildings where they have advantages in low-temperature systems, as it is well documented in the paper. The comparison of real thermodynamic processes with thermodynamically most favorable Camot＇s process is made. The results in the paper show that COP is diminishing with increasing of condensing temperature and also depends on real properties of working fluids. The impact of compressor efficiency for two real working media is also analyzed in the paper. There is significant diminishing of COP with diminishing of compressor efficiency. The intension of the paper is to help better understanding of this very effective and prosperous technology, and to encourage its development, production, and efficient application.

C12-3.43/0.981 Type 12MW Exhaustion and Condensing Stean Turbine

TheQingdaoJienengPowerGroupCompanyinShandongmanufactUreseightseriesofsteamtIJrbinesin140varieties,witheachturbinebelow25MaTheC12-3.43/0.98type12MWexhaustionandcondensingsteamturbinehasthefollowingfeatures:12mW:ipa,435C,0.981Mpa,andh/h,whichcanbeusedi...

Condensing Heat Exchanger

The paper shows a method of designing a heat exchanger recovering heat from the condensation of water vapour contained in flue gases. A heat exchanger condenses water vapour and SO2 （sulphur dioxide） in the presence of inert gases （CO2, CO, N2, O2） contained in flue gases. A mathematical model and a sample design of a heat exchanger were presented. The heat exchange is capable of recovering from a dozen or so to several dozen percent of heat from flue gases escaping into the atmosphere. A second advantage of the heat exchanger is the possibility to reduce the emissions of SO2 considerably. Depending on the parameters, it can be even a sevenfold reduction in the emissions. The main mathematical tool used for designing the condensing heat exchanger is the Colburn-Hougen method. The authors omitted that part of the method which requires iterative calculations. The Mollier diagram was used instead.

Performance improvement of air-breathing proton exchange membrane fuel cell(PEMFC) with a condensing-tower-like curved flow field

Air-breathing proton exchange membrane fuel cells(PEMFCs) are very promising portable energy with many advantages. However, its power density is low and many additional supporting parts affect its specific power. In this paper, we aim to improve the air diffusion and fuel cell performance by employing a novel condensing-tower-like curved flow field rather than an additional fan, making the fuel cell more compact and has less internal power consumption. Polarization curve test and galvanostatic discharge test are carried out and proved that curved flow field can strengthen the air diffusion into the PEMFC and improve its performance. With appropriate curved flow field, the fuel cell peak power can be 55.2%higher than that of planar flow field in our study. A four-layer stack with curved cathode flow field is fabricated and has a peak power of 2.35 W(120 W/kg).

基于特征选择及Condensing技术的文本取样

作为一种基于实例的方法,k-近邻(kNN)分类器有大量的计算及存储需求.同时,训练数据分布的不均衡,也会导致kNN分类器的性能下降.针对这些缺陷,文中提出特征选择与Condensing技术相结合的取样方法,以达到下述目的.在减少kNN分类的计算量及存储量的同时,保证分类器的性能.首先由传统的特征选择方法产生训练集里每类训练数据的特征.再根据文档自身的类特征,结合Condensing策略移去多余的训练实例.大量实验表明,用该方法所取得的样本作为训练集,不仅极大减少kNN方法的时空开销,而且降低噪声,提高分类器性能.

Finite-Time Thermodynamic Simulation of Circulating Direct Condensation Heat Recovery on Chillers

A time series model is used in this paper to describe the progress of circulating direct condensation heat recovery of the compound condensing process (CCP) which is made of two water cooling condensing processes in series for a centrifugal chiller in the paper. A finite-time thermodynamics method is used to set up the time series simulation model. As a result, an upper bound of recoverable condensation heat for the compound condensing process is obtained which is in good agreement with experimental result. And the result is valuable and useful to optimization design of condensing heat recovery.

Novel interface engineering of LDH-based materials on Mg alloy for efficient photocatalytic systems considering the geometrical linearity of condensed phosphates

This study presents a facile and rapid method for synthesizing novel Layered Double Hydroxide(LDH)nanoflakes,exploring their application as a photocatalyst,and investigating the influence of condensed phosphates'geometric linearity on their photocatalytic properties.Herein,the Mg O film,obtained by plasma electrolysis of AZ31 Mg alloys,was modified by growing an LDH film,which was further functionalized using cyclic sodium hexametaphosphate(CP)and linear sodium tripolyphosphate(LP).CP acted as an enhancer for flake spacing within the LDH structure,while LP changed flake dispersion and orientation.Consequently,CP@LDH demonstrated exceptional efficiency in heterogeneous photocatalysis,effectively degrading organic dyes like Methylene blue(MB),Congo red(CR),and Methyl orange(MO).The unique cyclic structure of CP likely enhances surface reactions and improves the catalyst's interaction with dye molecules.Furthermore,the condensed phosphate structure contributes to a higher surface area and reactivity in CP@LDH,leading to its superior photocatalytic performance compared to LP@LDH.Specifically,LP@LDH demonstrated notable degradation efficiencies of 93.02%,92.89%,and 88.81%for MB,MO,and CR respectively,over a 40 min duration.The highest degradation efficiencies were observed in the case of the CP@LDH sample,reporting 99.99%for MB,98.88%for CR,and 99.70%for MO.This underscores the potential of CP@LDH as a highly effective photocatalyst for organic dye degradation,offering promising prospects for environmental remediation and water detoxification applications.