Corrosion Inhibition by Co-Immobilized Lysozyme and Lipase in Circulating Cooling Water System

The corrosion inhibition performance of co-immobilized lysozyme and lipase was investigated in a recirculating cooling water system. Four methods were carried out in co-immobilization, and the operating parameters were optimized by using the respond surface methodology(RSM). The corrosion inhibition performance of co-immobilized lipase and lysozyme was evaluated by weight loss measurements and electrochemical measurements. The results revealed that the optimal co-immobilization method should be the sequential immobilization of lysozyme and then lipase. The inhibition efficiency was 86.10% under the optimal co-immobilized conditions. Electrochemical data showed that co-immobilized lysozyme and lipase was a mixed-type inhibitor and the corrosion inhibition efficiency was 81%.

Optimization of circulating cooling water systems based on chance constrained programming

Recent research on deterministic methods for circulating cooling water systems optimization has been well developed. However, the actual operating conditions of the system are mostly variable, so the system obtained under deterministic conditions may not be stable and economical. This paper studies the optimization of circulating cooling water systems under uncertain circumstance. To improve the reliability of the system and reduce the water and energy consumption, the influence of different uncertain parameters is taken into consideration. The chance constrained programming method is used to build a model under uncertain conditions, where the confidence level indicates the degree of constraint violation. Probability distribution functions are used to describe the form of uncertain parameters. The objective is to minimize the total cost and obtain the optimal cooling network configuration simultaneously.An algorithm based on Monte Carlo method is proposed, and GAMS software is used to solve the mixed integer nonlinear programming model. A case is optimized to verify the validity of the model. Compared with the deterministic optimization method, the results show that when considering the different types of uncertain parameters, a system with better economy and reliability can be obtained(total cost can be reduced at least 2%).

MIC in Circulating Cooling Water System

MIC is one of the main problems of circulating cooling water system. The direct economic loss by MIC is about 300 to 500 billion dollars. It is good to understand MIC in order to control MIC. Source and species of microorganisms was introduced firstly. There are three kinds of microorganisms in the system, including bacteria, fungi and algae. Species of these microorganisms are shown in the paper. Then, mechanisms of MIC are analysed. Although there is no universal mechanism of MIC, MIC is still mainly an electrochemical corrosion in nature. Meanwhile, the mechanisms on SRB and iron bacteria are introduced in details. At last, several methods of microorganisms control are put forward in the paper.

Ion Exchange Softening and Alkalization Treatment for Zerodischarge of Circulating Cooling Water

In order to solve the problems including pipe corrosion, scaling and microbial growth, which severely threat safe op-eration of circulating cooling water system, this paper proposes ion exchange softening and alkalization process to solve these problems and carries out a series of studies to study the feasibility of ion exchange softening and alkaliza-tion process in the simulation process of circulating cooling water system. The studies include product water quality of ion exchange softening and alkalization process, effect on the performance of carbon steel and brass, and the inhibition that suppresses microbial growth. The results indicate that ion exchange softening and alkalization process is feasible to prevent the circulating cooling water system from scaling, pipe corrosion, and microbial growth without any other chemicals. Thus circulating cooling water system can achieve zerodischarge of wastewater.

Laccase Immobilized on Mesoporous Silica Materials and Its Corrosion Inhibition Performance in Circulating Cooling Water System

Mesoporous SiO_2 microspheres were synthesized using the sol-gel method and were characterized by TEM, FT-IR and BET techniques. The diameter of the microspheres is about 100—150 nm, and the average mesopore diameter is 2.55 nm, while the specific surface area is 1 088.9 m2/g. Mesoporous SiO_2 microspheres adsorb glutaraldehyde and immobilize laccase by means of the aldehyde group in glutaral which can react with the amidogen of laccase. The immobilization conditions were optimized at a glutaraldehyde concentration of 0.75%, a crosslinking time of 8 h, a laccase concentration of 0.04 L/L and an immobilization time of 10 h. When diesel leakage concentration was 80 mg/L, the highest corrosion inhibition efficiency of immobilized laccase reached 49.23%, which was slightly lower than the corrosion inhibition efficiency of free laccase(59%). The diesel degradation ratio could reach up to 45%. It has been proved that the immobilized laccase could degrade diesel to inhibit corrosion.

电化学水处理技术降低循环水硬度的实验研究

使用电化学法处理某焦化企业实际循环水的实验,探究了循环水的硬度和碱度去除率随处理时间的变化情况。分析了电流密度、水力停留时间、极板间距等实验操作参数以及商用阻垢剂对电解效果和能耗的影响。结果表明:硬度和碱度去除率随处理时间呈现先上升后平稳的趋势,且碱度去除率总是高于硬度去除率;电流密度为70 A/m^(2)、水力停留时间为6 min、极板间距为3 cm时电解效果最佳,硬度和碱度去除率可达27%以上,单位能耗低至13 kWh/kg;商用阻垢剂对电解效果具有阻碍作用。

电化学循环水阻垢技术在电力行业的应用展望

在工业发展中,循环冷却水的结垢问题一直备受关注,有效的阻垢技术对降低生产能耗和减少水资源的浪费具有重要意义。电化学阻垢技术因具有高效、无需投加药剂、同步杀菌等优点受到了广泛的关注。从电化学阻垢技术的发展、原理以及实际应用等方面,综述了电化学阻垢技术在循环冷却水处理中的应用情况并展望了在电力行业冷却水处理中的应用前景。包括以时间为向导结合文献计量学可视化分析,比较了近十年阻垢技术相关研究热点;进一步从电化学阻垢技术的简介、与传统阻垢技术的比较、研究现状以及影响因素出发,并结合实际应用情况,提出了电化学阻垢技术尚且存在的困难和挑战,最后对电化学阻垢技术在电力行业中的应用前景进行了展望。

石墨炉原子吸收测定间接空冷机组循环水中的痕量铝

采用石墨炉原子吸收测定SCAL型间接空冷机组循环水中的痕量铝,从石墨炉工作参数、基体改进剂、试剂空白、水样前处理等方面进行了实验条件优选。实验结果表明:石墨炉灰化温度、原子化温度分别为700℃和2 700℃,不加基体改进剂条件下,铝离子标液质量浓度在0~20μg/L范围内标准曲线线性相关系数可达到0.999 8,相对标准偏差小于10%,检测下限为0.5μg/L。采用水样酸化静置1 h后直接测定并与标准加热消解法测定值进行了对比,相对误差小于5.0%,空白值小于0.5μg/L,有效解决了加热消解法空白值高的问题,提高了间接空冷机组循环水中小于10μg/L痕量铝测定的准确性。

槐米提取物/PBTCA复配物阻硫酸钙垢性能研究

采用静态阻垢法研究了槐米提取物和其与市售2-膦酸基丁烷-1,2,4-三羧酸(PBTCA)二元复配物对循环冷却水阻硫酸钙垢性能。结果表明,单一的槐米提取物阻硫酸钙垢效果随槐米提取物浓度的增加呈先增加后递减的趋势,最佳的浓度为21 mg/L,阻垢率可达20.45%;槐米提取物与PBTCA的二元复配物呈现较好的阻硫酸钙垢性能,在质量配比PBTCA∶槐米提取物=1∶2,投加量为21 mg/L,保温时间4 h, CaCl_(2)浓度5.55 mg/mL,保温温度70℃时,阻硫酸钙垢率达到93.75%,硫酸钙垢未见明显的规整结构而呈团块状;热重分析表明,槐米提取物在250℃时可发生分解,表现良好的热降解性能。

QDQ2-1型水电解制氢设备冷却循环水控制改进方法研究

为了保障制氢设备的良好运行,文章进行水电解制氢设备冷却循环水控制改进方法的研究,利用温度控制电路将电解槽温度控制在预设范围,使水电解制氢设备始终工作在最佳温度。通过10个月的试用检验,设备未出现超温停机现象,改造效果理想。研究方法具有在同型号制氢设备中推广的可行性。

水能风机在循环水冷却系统的应用

介绍了循环水冷却系统中采用水能风机代替大功率电动机实现节能降耗的实施措施,分析了改造后带来的经济效益。

循环冷却水系统的电化学水质稳定技术案例分析

水垢沉积和金属腐蚀会导致循环冷却水系统传热效率下降和能耗增加,严重影响工业生产的安全稳定运行。以某厂循环水系统的电化学除垢设备为案例,通过分析其处理效果和经济效益,为电化学技术处理循环冷却水的应用推广提供依据。现场所得运行数据表明,该厂所采用的电化学除垢设备能够有效改善水质,防止结垢,控制循环冷却水系统的腐蚀情况。每年减少循环水系统补水量和排污量各4.38×10^(5) t,并显著降低药剂投加量。经济核算显示该电化学系统每年可节省约212.9万元。

焦炭与不锈钢耦合阴极的电化学水软化性能研究

以304不锈钢网作为外层支撑床,锯齿不锈钢网作为内部支撑结构,在复合锯齿网的锯齿空隙中填充焦炭,制备了一种由焦炭与不锈钢两种材料耦合的填充床电极,用于解决电化学水软化阴极无法长期高效运行的问题。探究了最优的电极结构参数,结果表明,在阴阳极间距、外层平网孔径和表观电流密度分别为1.5 cm、20目、80 A/m^(2)时,电极对总硬度为700 mg/L的模拟循环冷却水的软化速率达到最佳,为46.873 g(/m^(2)·h)。当电极表面被垢层覆盖导致软化速率大幅下降时,通过振动方式对电极进行再生,研究了电极的使用寿命,结果表明,维持电极连续工作37 d,电极对循环冷却水仍保持较高的软化速率,可维持电化学水软化系统的长期高效运行。本研究可为解决电化学水软化阴极因无法有效再生导致的电化学水软化系统性能下降问题提供参考。

高炉软水密闭循环冷却系统水温调控分析与探讨

介绍了首钢股份4 000 m~3高炉的软水密闭循环冷却系统的工艺流程、系统特点与运行效果。高炉软水密闭循环系统采用闭式冷却塔冷却降温,冷却水采用循环供水方式,通过冷却水量的合理分配,实现对软水的可靠降温。根据十年来的实际运行情况,对软水密闭循环冷却系统水温调控存在的问题进行了整改,有效提升了降温能力,提高了系统的供水安全性。

充水式潜水电机温度场仿真分析

为了避免充水式潜水电机在运行过程中局部过热导致绝缘失效,造成匝间短路故障的问题,提高电机运行的可靠性,以一台500k W充水式潜水电机为例,搭建了充水式潜水电机包括冷却器、外部水道、吸水罩在内的三维全域温度场仿真模型。模型对定子槽内部分进行了简化的同时考虑了定子槽内冷却水的流通,进一步提高了温度场仿真的精度。最后,对充水式潜水电机内外循环散热过程进行了仿真分析,并通过搭建充水式潜水电机试验平台对温度场仿真结果进行了验证。

电磁场与电化学对循环冷却水系统中设备腐蚀及结垢的影响

循环冷却水对工业生产至关重要,但若长期使用,会使传输管道及换热设备产生腐蚀和结垢,这一直是循环冷却水使用过程中存在的顽疾。将环保、高效、时兴的新技术电磁场(旋磁加能器)和电化学(吸垢仪)创新地联合运用到水质更差的中水中,探索这种联合技术在循环冷却水系统上的防腐、防垢效果。通过搭建的小型工业水循环系统平台,验证了这种联合技术可有效减少循环冷却水系统的腐蚀和结垢问题,改善循环冷却水系统的运行状态,另外,为工业循环水企业提供了将中水用作循环冷却水的新思路,可为企业增加经济效益,实现节能减排。

炼化企业污水回用至循环水系统的分析研究

我国水资源匮乏的问题日益突出,工业企业节水减排工作的重要性逐步提升。对某炼化企业的两套生化装置污水的水质条件及各生产单元的用水量等数据进行分析,初步确认了适合回用至循环冷却水系统的煤化工生化装置污水,水量为140 m3/h。在不同的回用方案条件下,根据循环水水质标准计算该方案可以达到的最高浓缩倍数,得到两种优化回用方案,实现了污水回用背景下的循环水系统高浓缩倍数(≥5)运行。后续将继续在循环水药剂优化和污水处理单元提标改造等方面进行研究,进一步提升污水回用率,实现节水减排的更高目标。

考虑节能节水协同的循环水系统优化及应用

作为过程工业中高能耗辅助系统的代表,循环水系统表现出用户多、系统复杂、能耗高等特性,决定了工业循环冷却水的研究重点集中在系统节能和降低总体水量这两个方面。本文提出了工业循环冷却水系统的多尺度整体协同优化策略,从系统与设备层面进行循环冷却水系统的多尺度优化,以降低整体水耗和能耗。以国内某炼油厂的单个循环水系统优化为例,节能节水协同优化与改造前相比,系统节水25.6%,考虑长周期运行情况,节水23.6%,系统节能25.6%。

毛薯提取物的制备及阻垢缓蚀性能研究

通过浸提法对毛薯水提物(HPE)进行制备,并对毛薯提取物的阻碳酸钙垢、硫酸钙垢以及缓蚀性能进行了评价。结果发现,随着毛薯提取物浓度增加,其阻碳酸钙、硫酸钙垢率以及缓蚀率均有所提高。当毛薯提取物浓度为1500 mg/L时,阻碳酸钙垢效率达到61.0%;当提取物浓度达到200 mg/L时,阻硫酸钙垢效率接近100%;当毛薯提取物浓度为500 mg/L时,其在0.1 mol/L硫酸溶液中的缓蚀率可达80%左右。在探究加热时间、温度、Ca^(2+)浓度变量与阻垢率之间的关系时,发现随着变量条件的提高,阻碳酸钙、硫酸钙垢率均出现了不同程度的下降。结果表明,毛薯提取物具有较好的阻垢、缓蚀性能。

工业循环冷却水腐蚀影响因素研究

通过模拟现场工业循环冷却水的运行条件,采用旋转挂片法、动电位极化曲线法,开展氯离子、流速、硫化物、氨氮等重要水质运行参数对碳钢、不锈钢、铜材质的腐蚀影响实验,分析超滤处理及在用药剂配方对中水回用的腐蚀性影响,并根据实验结果进一步优化循环水水质管控,降低循环冷却水的腐蚀性。