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.

Transient Heat Transfer Study of Direct Contact Condensation of Steam in Spray Cooling Water

We conducted a transient experimental investigation of steam–water direct contact condensation in the absence of noncondensible gas in a laboratory-scale column with the inner diameter of 325 mm and the height of 1045 mm. We applied a new analysis method for the steam state equation to analyze the molar quantity change in steam over the course of the experiment and determined the transient steam variation. We also investigated the influence of flow rates and temperatures ofcooling water on the efficiency ofsteam condensation. Our experimental results show that appropriate increasing of the cooling water flow rate can significantly accelerate the steam condensation. We achieved a rapid increase in the total volumetric heat transfer coefficient by increasing the flow rate of cooling water, which indicated a higher thermal convection between the steam and the cooling water with higher flow rates. We found that the temperature ofcooling water did not play an important role on steam condensation. This method was confirmed to be effective for rapid recovering ofsteam.

Optimized Operation of a Solar-Driven Thermoelectric Dehumidification System for Fresh Water Production

The work presents a parametric analysis of the performance of a solar-driven thermoelectric system to dehumidify air and produce fresh water. The system is combined with a solar distiller humidifying ambient air to enhance distillate output to meet the specified fresh water needs for a residential application. The presented system is a totally renewable energy-based system taking advantage of the clean solar energy. A model is developed to simulate the air dehumidification process using TEC （thermoelectrically cooled） channels. An optimization problem for setting system operational parameters is formulated to meet the fresh water requirement of 10 liters per day for a typical residential application in the Lebanese coastal humid climate. Using five TEC channels of length of 1.2 m and area of 0.07 - 0.05 m^2 integrated with 1.2 m^2 solar distiller is capable of meeting the water demand, where the air mass flow rate introduced to each TEC channel is optimally set at 0.0155 kg/s. The optimal electrical current input to the TEC modules from the photovoltaic solar panels varied depending on the month and is set at 2.2 A in June, 2.1 A in July and 2.0 A in August, September and October per each TEC module.

基于电磁场技术的TriIns Water系统在水处理中的应用研究

循环冷却水处理是诸多工业生产和中央空调系统运维的关键一环,良好的阻垢、缓蚀、微生物控制可以延长设备的使用寿命并降低其能耗。文章介绍的TriIns Water智水系统是一种专门为循环冷却水处理系统设计的全方位纯物理解决方案,绿色、智能、环保、节能,能够有效控制循环冷却水处理中的三大问题,完全无化学药剂添加。该系统在循环冷却水处理系统中进行了应用,取得了良好的效果,零排污废水的特性完全符合当前的环保形势,是一项对环境友好的绿色节能技术,可推广应用于分布式能源站、发电厂、钢铁厂及石化厂等循环冷却水系统。

Performance Analysis of Automated Control System for Condenser Water Treatment Unit

The air conditioning system in the Umm Al-Qura University (Albdiya Campus) was conceived to be a district cooling by a remote chilled water plant. Recently, there are two chilled water plants in the university installed strategically to provide chilled water to all the academic and administrative buildings of the university through distribution network with total capacity approximately of 12,000 tons of refrigeration. The plants were built based on cooling towers with open water cycle as heat rejection system. Water treatment chemicals has been used to protect the cooling systems from corrosion, scaling and microbiological fouling accompanied with dissolved and suspended water impurities. Different methods are being used to determine and control the treatment chemical concentrations and system performance indicators. Traditional chemical controller has drawback of indirect measurements and set points. The purpose of this paper is to present a solution to overcome the problems of traditional and conventional chemical treatment and control sys-tems. Central cooling plant number (1) assigned to perform experimental setup using new chemical treatment technology. Advanced automatic chemical treatment controller installed on condensers (1, 2 and 3), and certain key performance indicators were selected and monitored such as chemical and water consumption, power, energy saving, and maintaining system integrity and efficiency. Satisfactory results were obtained in terms of performance and cost of operation.

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。

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。

自然通风湿式冷却塔节水方案的数值研究

为降低自然通风湿式冷却塔的耗水量,本文采用一种可用于回收其蒸发损失的空气冷凝器结构,并通过数值模拟方法对其节水特性展开研究。首先基于空气运动控制方程和水蒸气冷凝模型,建立了用于分析空气冷凝器节水特性的数学模型,其次分析了冷却空气流速、空气冷凝器的结构尺寸和材质等因素对该冷凝器节水特性的影响。研究结果表明:空气冷凝器的单位面积节水量随着冷却空气流速以及冷凝器宽度的增大而增大,但随着冷凝器长度和高度的增大而减小;空气冷凝器的材质和壁厚对其单位面积节水量没有显著影响,空气冷凝器可采用重量轻和成本低的薄壁PVC来加工制造。

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。

2023年中南某市夏季公共场所嗜肺军团菌污染状况

目的了解2023年中南某市三类公共场所嗜肺军团菌污染状况,分析健康风险。方法于2023年7月采取非随机抽样方法在在中南某市三类公共场所采集集中空调水样、室内空气样本,以及公共设施物体表面样本进行检测和分析。采用培养法对集中空调冷却水和冷凝水嗜肺军团菌进行检测;采用荧光定量PCR对室内空气以及物体表面嗜肺军团菌进行检测。利用Fisher确切概率法用于评估水样类型、场所类型与健康风险等级的相关性。结果调查中共采集集中空调水样24份、室内空气样本213份以及公共设施物体表面样本282份。培养法检测结果显示,集中空调水样的总体阳性率为37.5%,其中冷却水的阳性率为55.6%(5/9),冷凝水的阳性率为26.7%(4/15)。其中,地铁站的集中空调水样阳性率为27.3%(3/11),宾馆的阳性率为66.7%(6/9),火车站水样中未检测出嗜肺军团菌(0/4)。风险分析发现,冷却水的高风险率为55.6%(5/9),冷凝水的高风险率为20.0%(3/15);地铁和宾馆水样的高风险率分别为27.3%(3/11)和55.6%(5/9)。荧光定量PCR结果显示,公共场所的室内空气和物体表面的检测结果均为阴性,中高风险率为0%。结论三类公共场所中,地铁和宾馆嗜肺军团菌阳性率较高,冷却水和冷凝水中均有较高检出率。

大型冷凝式消雾节水冷却塔性能试验研究

为研究获得菱形模块消雾节水冷却塔的消雾节水和节能特性,对某设计循环水量为5000 m^(3)/h的菱形消雾节水冷却塔的消雾性能、节水性能和节能性能进行了试验研究。建立了冷却塔消雾节水节能性能评价模型,通过现场试验获得冷却塔消雾节水和节能特性参数及其变化规律。结果表明:消雾节水冷却塔设计出塔空气相对湿度为85%,实测出塔相对湿度为82.28%,消雾指数为1.03,符合“零雾型”消雾冷却塔的要求。经菱形消雾冷凝模块换热后的冷凝水量为14.19 m^(3)/h,冷却塔节水率为25.3%,冷凝节水效果好。单塔年总节能收益约40万元,整体年节能收益达240万元,菱形消雾节水冷却塔具有良好的经济效益及环保效益。

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。

基于外部冷却模块和内部凝雾模块的高位收水机械通风冷却塔性能对比研究

为了控制雾羽和节约水资源,搭建了高位收水机械通风冷却塔热态实验系统,分别对外部冷却模块(干湿联合冷却塔)和内部凝雾模块(凝雾式冷却塔)的消雾、节水及热力性能进行对比分析,研究了环境温度、循环水进水温度及循环水量对冷却塔性能的影响。结果表明:干湿联合冷却塔和凝雾式冷却塔均具有消雾和节水能力,但实现二者的消雾和节水是以降低冷却塔冷却性能为代价的;与原塔相比,干湿联合冷却塔和凝雾式冷却塔的循环水温降约降低了1.5 K;干湿联合冷却塔和凝雾式冷却塔的消雾和节水性能受运行参数的影响很大,且凝雾式冷却塔的节水量和节水率高于干湿联合冷却塔。