渤海石油平台的腐蚀与防护

<正> 渤海中使用十几年的石油平台,普遍腐蚀严重,有的已不能继续使用。最严重的是在飞溅区,腐蚀速度甚至超过0.5mm/Yr,低潮位附近和大气区的腐蚀也不容忽视,保护不当的已发生局部腐蚀,有的出现腐蚀洞。 渤海石油平台的保护经历了三个阶段。早期因对腐蚀与防护缺乏认识,措施不力,保护效果很差。1973年后,由于技术力量增加和技术进步,措施得到加强,阴极保护普遍采用,但由于管理等原因,保护效果还不很理想。近几年合资建造的平台,按国际规范引进了技术和材料,使防护工作推进了一大步。 为了确保平台安全,必须十分重视防护工作;平台的设计、建造和维护,应遵循有关规范和标准;防护工作者要不断提高和完善保护技术,同时兼顾保护效果和经济效益。     

Thermal hydraulic performance analysis of the printed circuit heat exchanger using a helium test facility and CFD simulations

The thermal-hydraulic performance of the PCHE was investigated using the KAIST helium test loop. Experiments were performed in the helium laminar region with 350 < Re < 1200. The hot/cold side inlet conditions were 25–550 °C/25–100 °C over the operating pressure of 1.5–1.9 MPa, respectively. Mass flow rates were controlled in the range of 40–100 kg/h. Pressure drop and temperature difference were measured at the inlet and outlet of the hot and cold sides. A global Fanning factor correlation and a global Nusselt number correlation were proposed using information only at the inlet and outlet of the hot and cold sides. A three-dimensional (3-D) numerical simulation was performed using FLUENT, a commercial computational fluid dynamics (CFD) code, to compare simulation results to the KAIST helium test data and to obtain the local Nusselt number in the PCHE. CFD predictions showed good agreement with experimental data. A local pitch-averaged Nusselt number correlation was proposed using local temperature, pressure, surface heat fluxes, and properties provided by CFD simulations. The system analysis code, GAMMA, was also utilized to identify which correlation was more applicable for system analysis. It turns out that the proposed local pitch-averaged Nusselt number correlation from CFD simulations is more appropriate than the global Nusselt number correlation developed from experimental data.     

基于PC/104的武装直升机外场检查仪设计

为提高检查仪的野战化、智能化和通用化能力,文中采用嵌入式的PC/104标准总线计算机作为主控部件,配以相应的检测接口电路和外围模拟电路,设计出了武装直升机外场检查仪.该检查仪在设计时充分考虑内、外场的检测、检修项目和工作环境特点,可以保证检测设备在不同使用环境下有较强的适应能力,缩短了检测时间,提高了检测结果的可靠性.     

Measurement of heat transfer coefficients for direct contact condensation in core makeup tanks using holographic interferometer

The present work is to improve our understanding and analysis of direct contact condensation on the gravity injection of CMTs and to measure the heat transfer coefficients around steam bubbles using the holographic interferometer and high speed camera. The condensation regime map associated with the downward injection of steam into water through the steam pipe is investigated to understand the mechanism of the direct contact condensation. The present map shows that the boundary of chugging and subsonic jetting with the larger diameter pipe is shifted to the larger steam mass flux. Steam cavity mode, not found in the literature, and the unique mode of downward injection for the present geometry, is observed at the low subcooled water temperature. With the holographic interferometry and the high speed camera, the heat transfer mechanism for the direct contact condensation in CMTs is understood and the heat transfer coefficients are measured.     

Evaluation of system codes for analyzing naturally circulating gas loop

Steady-state natural circulation data obtained in a 7 m-tall experimental loop with carbon dioxide and nitrogen are presented in this paper. The loop was originally designed to encompass operating range of a prototype gas-cooled fast reactor passive decay heat removal system, but the results and conclusions are applicable to any natural circulation loop operating in regimes having buoyancy and acceleration parameters within the ranges validated in this loop. Natural circulation steady-state data are compared to numerical predictions by two system analysis codes: GAMMA and RELAP5-3D. GAMMA is a computational tool for predicting various transients which can potentially occur in a gas-cooled reactor. The code has a capability of analyzing multi-dimensional multi-component mixtures and includes models for friction, heat transfer, chemical reaction, and multi-component molecular diffusion. Natural circulation data with two gases show that the loop operates in the deteriorated turbulent heat transfer (DTHT) regime which exhibits substantially reduced heat transfer coefficients compared to the forced turbulent flow. The GAMMA code with an original heat transfer package predicted conservative results in terms of peak wall temperature. However, the estimated peak location did not successfully match the data. Even though GAMMA's original heat transfer package included mixed-convection regime, which is a part of the DTHT regime, the results showed that the original heat transfer package could not reproduce the data with sufficient accuracy. After implementing a recently developed correlation and corresponding heat transfer regime map into GAMMA to cover the whole range of the DTHT regime, we obtained better agreement with the data. RELAP5-3D results are discussed in parallel.     

裂缝发育带地震识别预测技术研究进展

裂缝性储层在全球有广泛的分布，裂缝油气藏勘探在油气勘探中占有重要位置。但是裂缝的成因复杂，其发育程度受多种因素控制。地震资料中虽包含有裂缝信息，但是因裂缝因素引起的地震响应要远远小于其他地质因素引起的响应，因此利用地震资料识别裂缝存在困难。虽然如此，由于地震资料在横向连续性上的优势，人们还是认为地震方法在裂缝描述和预测中具有不可替代的作用。本文简要分析了利用地震资料进行裂缝研究的难点和对策，并总结了全球利用地震资料进行裂缝研究的主要技术和方法，为我国进一步开展这项研究工作提供借鉴。     

致密砂岩储集层裂缝综合录井识别技术研究

四川盆地油气勘探结果表明，盆地油气储集层普遍为致密砂岩非常规储集层，有效性主要取决于孔、洞、缝发育程度，因此在油气钻井中如何识别致密储集层的孔、洞、缝并确定其所在井段尤其重要。针对综合录井仪的0．1m钻时及相关参数的资料采集技术要求，通过对大量录井数据资料的统计和演算，建立起储集层裂缝发育程度及裂缝发育位置的3种储集层裂缝识别模型，即直接识别模型、地层可钻性（A值）识别模型、钻时回归（RWSR）值识别模型。系统阐述了致密砂岩储集层裂缝综合录井识别技术方法原理，详细介绍了致密砂岩储集层裂缝识别的3个模型在实际生产中的应用情况。该技术方法的研究在国内尚属首次，为油气勘探中储集层评价提供了一个新的方法和手段，可最大限度地发挥现代录井技术在油气勘探开发过程中的作用。