烟气露点是低温腐蚀的关键指标,制约着锅炉尾部排烟余热的深度利用。换热器表面积灰是传热特性恶化的主要原因,电站锅炉尾部烟气环境中,积灰与酸凝结共同作用影响换热器的传热特性。在含尘、含酸的烟气环境下对换热器传热特性进行热态实验研究,以套管换热器为基础,得到具有更高使用价值的烟气工程应用露点,结合传热特性随外壁温的变化情况,得到换热管传热特性随积灰及酸耦合的变化规律;并通过对不同外壁温下灰样的分析,得到不同酸凝结状况下积灰规律,得到实验环境下的工程应用酸露点温度为72℃,较传统热力学酸露点低35℃以上。

Flue gas dew point is the key indicator of low temperature corrosion, and restricts deep utilization of boiler flue gas heat. Fouling of heat exchanger surface is a major factor in deterioration of heat transfer. When fluid flows across heat exchange tubes, fouling and acid condensation influence heat transfer of heat exchanger. In the flue gas environment with dust and acid, a hot-state test was conducted to analyze heat transfer characteristics at different outer wall temperatures, and the dew point of flue gas for engineering application was obtained with a higher use value. The influence of the tubes’ heat transfer characteristics with varying fouling and acid condensation was determined. Ash deposition with different amounts of acid condensation was investigated through analyzing the ash samples at different outer wall temperatures. The value of applied dew point for engineering was given as 72℃, which was at least 35℃ lower than the acid dew point in thermodynamics.

天然气饱和含水量或者水露点计算为天然气集输与加工过程重要的环节,一旦温度达到或低于天然气压力所对应的露点温度,天然气就有水析出,导致管道或其他设备腐蚀。所以比较精确的估计、方便的计算天然气露点与饱和含水量之间的关系是非常重要的。利用相平衡原理,结合逸度计算的经验公式,开发了天然气、尤其是酸性天然气水露点与含水量之间关系的计算程序。

The saturation moisture content calculation or the water dew point calculation of natural gas is an important part for natural gas transportation and processing process. Once the temperature reaches or falls below the dew point temperature corresponding to the natural gas pressure, the natural gas will have water precipitation,which can cause corrosion of pipes and other equipments. Therefore, it is important to accurately estimate and conveniently calculate the relationship between natural gas dew point and saturation moisture content. Based on phase equilibrium principle and empirical formula of fugacity calculation, a computer program to calculate the relationship for natural gas, especially sour gas, was developed.

提出一种基于MEMS技术的电容式传感器,结合ARM Cortex-M3嵌入式处理器搭建电容式水汽测量系统的测控系统,以实现大气环境中的高精度湿度测量。为提高测量精度和分辨率,利用24 bitΣ-Δ数模转换器测量露点和温度。通过PID控制算法对半导体制冷器进行控制,使贴有MEMS露点传感器和温度传感器的制冷器冷端表面温度降低。当MEMS露点传感器表面温度低于露点时,其表面会产生露珠,引起MEMS电容增大。MEMS露点传感器电容值可以通过24 bitΣ-Δ电容数字转换器测量。通过Goff-Gratch方程和露点湿度转换关系,可计算出到大气湿度。测量结果表明,该系统的露点测量精度可达约±0.2℃。

Combined with a Cortex-M3 ARM processor,a capacitive sensor based on MEMS technology is proposed for constructing a capacitive water vapor measurement system, which is used to achieve precision humidity measurement in atmospheric environment. A 24-bit∑-△ADC is applied to measure temperature. By cooling a ther-moelectric cooler which is modulated by voltage,the temperature of TEC’s surface with the MEMS sensor can be precisely controlled. When the temperature of MEMS sensor reaches the dew point,dew will emerge on the MEMS structure,which induces the increment of MEMS capacitance. A 24-bit ∑-△ capacitance-to-digital converter is utilized to measure the capacitance of MEMS sensor. After the translating dew point to humidity using Goff-Gratch Equation, atmospheric humidity is obtained to complete the design of this water vapor measurement system. Measurement results show that the dew point error is typically less than±0. 2 ℃.

对国内AW煤层气进行三甘醇法（TEG）脱水工艺模拟分析，可以得出：随着原料煤层气压力增大，脱水率增大，水露点降低，但变化的幅度均逐渐减小；原料气温度则相反，温度升高时，水露点升高和脱水率降低，变化幅度逐渐增大；进料量增大时出现“吹液”而使得脱水效果降低；随贫液温度升高，水露点和脱水率分别呈线性增大和减小，但总体上影响不大；综合考虑制造成本和脱水效果，存在一个最优塔板数，若在此基础上继续提高塔板数意义不大。

A TEG dehydration process of domestic AW CBM was simulated and analyzed. The results show that, the dehydration rate increases and the water dew point decreases with the increasing of raw CBM pressure, but the extent of change is diminishing;Effect of temperature on the dehydration is opposite, the dehydration rate reduces and the water dew point increases with the increasing of raw CBM temperature, and the extent of change is increasing;When inlet amount increases, blowing tower tray phenomenon may happen, which will cause the dehydration rate decrease;With barren solution temperature elevating, water dew point and the dehydration rate linearly increase and decrease respectively, but the overall impact is small;Considering costs and dehydration effect, there is a optimal absorber plate number.

电站地下厂房通风空调系统从2007年投入运行后，蜗壳层、水轮机层的管路结露严重。对电站运行工况进行了长期连续测试，结果表明：4—6月，结露现象较普遍，水管壁面温度低于环境空气的露点温度；7—8月，水管壁面温度高于环境空气的露点温度，结露现象基本消失。提出了具体的防结露措施：采用难燃型橡塑保温材料对部分管路进行保温；同时，根据季节选择适当的通风量，合理设计气流组织，相应开启不同数量的冷冻除湿机。

Since the operation of ventilation and air conditioning system of underground plants in 2007,the moisture condensation phenomenon occurs seriously on the pipeline.Performs the long-term and continuous test for operation condition of hydropower station.The result shows that condensation occurs commonly when surface temperature of water tube is lower than dew-point temperature of the ambient air from April to June,while this phenomenon vanishes basically from July to August since the surface temperature of water tube is higher than dew-point temperature of ambient air.Presents the following detailed anti-condensation measures, including performing the insulation on part of tubes with nonflammable material,selecting appropriate ventilation rate according to seasons,designing reasonable air distribution,and operating different numbers of refrigeration dehumidification machines.