Comprehensive Study on the Types, Performance, and Application of Cooling Tower 冷却塔的种类、性能及应用综合研究
Rajarshi Gupta 拉贾什·古普塔Civil Engineering, 土木工程Amity University, 阿米蒂大学，Kolkata, India, 印度 加尔各答，rajarshigupta01@outlook.com
Abhishek Mukherjee 阿比舍克·穆克吉Civil Engineering, 土木工程Amity University, 阿米蒂大学，Kolkata, India, 印度 加尔各答，abhishekmukherjee2209@outlook.comSudhakar Ranjan 苏达卡·兰詹School of Engineering and Technology, Apeejay Stya University, Apeejay Stya 大学工程与技术学院，Sohna-Palwal road, Gurugram, India, Sohna-Palwal road， 古尔冈， 印度，sudhakarranjanapj@outlook.com
Parikshit Vasisht 帕里克希特·瓦西什特
School of Engineering and Technology, Apeejay Stya University, Apeejay Stya 大学工程与技术学院，
Sohna-Palwal road, Gurugram, India, parikshitvasisht@outlook.com Sohna-Palwal road， 古尔冈， 印度， parikshitvasisht@outlook.com
Amit Deb 阿米特·德布Civil Engineering, 土木工程Amity University, 阿米蒂大学，Kolkata, India, amitdeb001@outlook.com 印度， 加尔各答， amitdeb001@outlook.com
Abstract 抽象
The cooling tower has a wide variety of applications in chemical and industrial plants. Cooling towers generally use the process of evaporation of water to reject the unwanted heat into the atmosphere to cool the system fluids. In a basic cooling system, the frame and casing of the unit behave as the medium for the transfer of extra heat out of the working system. The thermal energy is bumped off through the water which is later removed through direct contact with incoming cold close-circuit air. Though the casing facilitates the water distribution through various fills, which increases the surface area for the air-water contact enhancing the cooling effect, they are prone to the deposition of impurities, chemical sediments and spoil the overall efficiency and performance with time. The cooling tower packing adds to an additional rise in intense pressure loss within the system. So as to fight against this drawback, a larger amount of electrical energy is consumed. This study briefs on various components and working of the cooling towers. This work provides the various aspects of cooling tower applications, efficiency improvement, and uses in Civil Engineering Design. 冷却塔在化学和工业工厂中具有广泛的应用。冷却塔通常使用水蒸发过程将不需要的热量排入大气中，以冷却系统流体。在基本冷却系统中，设备的框架和外壳充当将额外热量从工作系统传递出去的介质。热能通过水被撞掉，然后通过与进入的冷闭路空气直接接触而被去除。虽然外壳有助于通过各种填料分配水，从而增加了空气-水接触的表面积，增强了冷却效果，但它们很容易沉积杂质、化学沉积物，并随着时间的推移破坏整体效率和性能。冷却塔填料增加了系统内强烈压力损失的额外增加。为了克服这个缺点，消耗了大量的电能。本研究简要介绍了冷却塔的各种组件和工作原理。这项工作提供了冷却塔应用、效率提高和在土木工程设计中应用的各个方面。
The cooling towers are the most crucial pieces of apparatus installed in the industrial or commercial processes. A simple description of a cooling tower can be something that eliminates “extra” heat from any process or acts as an air conditioning condenser to eliminate heat from the machinery into the surrounding atmosphere. 冷却塔是安装在工业或商业过程中的最关键设备。冷却塔的简单描述可以是消除任何过程中的“额外”热量，也可以充当空调冷凝器，将机器中的热量消除到周围大气中。
Cooling tower works in a way of Chiller: A “chiller” or “chiller unit” may be the compressor that works on an air conditioning or refrigeration principle, or it may be the evaporator of such a system or the fan coil unit in individual spaces (which is also an evaporator). The system may utilize separate units for each room, or a central unit which distributes the cooled air through entering into the rooms [1-7]. Fig 1 shows the working of basic cooling tower. Cooling tower is a type of apparatus used in the industrial process, for heat dissipation, used as a condenser (opposite to an evaporator) in power stations where there is insufficient water in a nearby river or lake to supply it like water cooled condenser. Water cooled cooling towers are also termed as “wet cooling towers” for they utilize water for the cooling of heated machinery. Such towers utilize natural evaporation process, by 冷却塔以冷水机组的方式工作：“冷水机组”或“冷水机组”可能是根据空调或制冷原理工作的压缩机，或者它可以是此类系统的蒸发器或各个空间的风机盘管机组（也是蒸发器）。该系统可以为每个房间使用单独的单元，或者使用一个中央单元，通过进入房间来分配冷却空气 [1-7]。图 1 显示了基本冷却塔的工作。冷却塔是一种用于工业过程的散热设备，用作发电站的冷凝器（与蒸发器相反），其中附近的河流或湖泊没有足够的水来供应它，就像水冷冷凝器一样。水冷冷却塔也被称为“湿式冷却塔”，因为它们利用水来冷却加热的机器。这种塔利用自然蒸发过程，通过
exchanging heat between the heated machinery, passing air and water in the tower. 在加热的机器之间交换热量，使空气和水进入塔中。
Fig. 1. Working of a cooling tower [8] 图 1.冷却塔的工作 [8]
Hot circulating water from the power station turbine condenser enters the cooling tower via sprayers where it is cooled by an air flow under natural draft. The cooled water is then re-circulated as cooling water for the power station condenser; in effect it is a raw water cooler similar to sea or river water but using air. The warm moist air exiting from the top is what creates the cloud that is often seen above cooling towers - this is due to the warm water and cooler air mixing which evaporates some of the water and thereby cools it. Fig. 2 shows cross-section of a typical closed circuit cooling tower. [6-7] HVAC (Heating Ventilation and Air Conditioning) in industrial applications may also use a form of cooling tower, but these are more generally known as air cooled condensers rather than cooling towers. There is air heater unit (AHU) present in cooling tower. In this case the compressed gas is passed through coils which are cooled by air, driven by a fan or multiple fans, thereby reducing its temperature which causes liquefaction of the gas. 来自发电厂涡轮冷凝器的热循环水通过喷雾器进入冷却塔，在自然气流下通过气流冷却。然后冷却水再循环作为电站冷凝器的冷却水;实际上，它是一种类似于海水或河水的原水冷却器，但使用空气。从顶部排出的温暖潮湿的空气产生了经常在冷却塔上方看到的云——这是由于暖水和冷空气混合，蒸发了一些水，从而冷却了它。图 2 显示了典型闭式冷却塔的横截面。[6-7] 工业应用中的 HVAC（供暖、通风和空调）也可以使用某种形式的冷却塔，但这些通常被称为风冷冷凝器，而不是冷却塔。冷却塔中存在空气加热器装置 （AHU）。在这种情况下，压缩气体通过由一个或多个风扇驱动的空气冷却的盘管，从而降低其温度，从而导致气体液化。
Fig. 2. A Typical Cross Section Of Closed Circuit Cooling Unit 图 2.闭式冷却装置的典型横截面
This system would be used where the ambient air temperature is low enough to reduce the size of the unit, or 该系统将用于环境空气温度足够低以减小设备尺寸的地方，或者
where cooling water is not available. Ships for instance use seawater which is a far better cooling medium than air owing to the relative specific heats. Sometimes these cooling towers are assembled to form “cells” of 2 or more cooling towers working individually. 没有冷却水的地方。例如，船舶使用海水，由于相对比热，海水是一种比空气更好的冷却介质。有时，这些冷却塔被组装成 2 个或多个冷却塔单独工作的“单元”。
II. COOLING TOWER'S BASIC COMPONENTS II. 冷却塔的基本部件
The main part of a cooling tower consists of: Structural packing (casing and frame), nozzles, fans, air bay, motors, fills, water basin, drift eliminators, etc. (Fig. 3 illustrates basic components of cooling tower.) Cold water basin: It is the water collection unit. In most of tower designs a water basin is positioned at the base, entirely beneath the fills, that collect cooled water flowing down the fills. 冷却塔的主要部分包括：结构填料（外壳和框架）、喷嘴、风扇、空气舱、电机、填料、水池、除水器等（图 3 说明了冷却塔的基本部件。冷水池：是集水单元。在大多数塔式设计中，水池位于底部，完全位于填料下方，用于收集流经填料的冷却水。
Packing: The exterior casings are followed by the frame, which is structurally set with fills, fans, motors, etc. Few glassfiber cooling towers have frames working as the casing that houses the different components. 填料：外壳后面是框架，框架在结构上设置有填充物、风扇、电机等。很少有玻璃纤维冷却塔将框架用作容纳不同组件的外壳。
Fills: Fills help in heat modulation by increasing the surface area of the water contact and air. Fills can be either splash or film type. There is a close spaced surface in film fills, water spreads on these and form a thin film. Film fills are more efficient in heat transfer than other types. Water is splashed on the horizontally placed bars which further breaks into small drops of water, in the splash fills. [8] 填充物：填充物通过增加水接触和空气的表面积来帮助热量调节。填充可以是 splash 或 film 类型。薄膜填充物中有一个紧密间隔的表面，水在这些表面扩散并形成薄膜。薄膜填充物的传热效率高于其他类型的薄膜填充物。水溅到水平放置的杆上，在飞溅填充物中进一步分解成小水滴。[8]
Drift eliminators: help in capturing water drops present in the air preventing them from losing into the atmosphere. 漂移消除器：帮助捕获空气中存在的水滴，防止它们流失到大气中。
Nozzle: The nozzles are the uniformly placed openings that ease the inappropriate wetting of the fills. These can be of different types, round, fixed, squared, or rotator type. 喷嘴：喷嘴是均匀放置的开口，可缓解填充物的不适当润湿。这些可以是不同的类型，圆形、固定、方形或旋转器类型。
Fans: Fans are used in maintain air flow through the system, as well as placed beneath the water basin for aiding in the evaporation process. Fans could be single speed or multispeed with adjustable speed. 风扇：风扇用于保持通过系统的气流，以及放置在水池下方以帮助蒸发过程。风扇可以是单速或多速，速度可调。
Air inlets: air inlets ease in the inflow of the air into the cooling tower. 进气口：进气口有助于空气流入冷却塔。
Fig. 3. Components and working of a basic cooling tower 图 3.基本冷却塔的组成部分和工作原理
III. Ways to Improve Efficiency of Cooling tower III. 提高冷却塔效率的方法
A number of solid wastes, such as magnesium, silica, chloride and calcium, etc. are left behind in the cooling towers that need to be filtered regularly otherwise these keep on dissolving and eventually spoil the cooling towers’ efficiency and performance or effect the equipment’s. 许多固体废物，如镁、二氧化硅、氯化物和钙等，会留在冷却塔中，需要定期过滤，否则它们会不断溶解，最终破坏冷却塔的效率和性能或影响设备。
Treatment of the cooling water is obligatory concerning any type of cooling tower. Whether it is a film types fill or splash fill type or counter or cross flow type it is necessary to treat a cooling tower periodically for the control of algal 对于任何类型的冷却塔，冷却水的处理都是强制性的。无论是薄膜类型的填充型或飞溅填充型，还是逆流型或错流型，都必须定期处理冷却塔以控制藻类
growth, suspended particles, etc. Water is conserved through increased COC or Cycles of Concentration by the cooling towers in large plants to reduce or make up significant water loss and requirements. Table I compares typical tower flow and fills. 生长、悬浮颗粒等。大型工厂的冷却塔通过增加 COC 或浓缩循环来节约用水，以减少或弥补大量的水损失和需求。表 I 比较了典型的塔流和填充。
These are some general checks and precautions for the cooling tower. Also it should be noted that only an on-site inspection will help an expert identify the right actions needed to improve efficiency. 这些是冷却塔的一些一般检查和预防措施。此外，还应注意，只有现场检查才能帮助专家确定提高效率所需的正确行动。
TABLE I - COMPARISON OF TYPICAL TOWER FLOW AND FILLS 表 I - 典型塔流和填料的比较
Comparison of Typical Tower flow and Fills 典型塔流和填料的比较
Comparison of Typical Tower flow and Fills
"Water Flow in tower: ∼13000 =16000m3//hr
Temp. of Cold Water* :∼30.0-33.0^(@)C
Temp. of Hot Water* :∼40.0-42.0^(@)C
Temp. of Wet Bulb :∼26.0-28.0^(@)C
No. of Towers (Cells) :2-3"
Counter Flow Film Fill Counter Flow Splash Fill "Cross-
Flow
Splash
Fill"
Area per Cell of Plant 14.1 xx14.1 "14.0 xx
14.1" "2.63 xx
5.50"
Fill's Height, Meter 1.5-1.6 5.2 11.0
Number of Cells/Tower 8 6 5-6
Motor Terminal/Tower power, kWh ∼253 ∼310 ∼330
Pumping Head (static), in meter 7.3 10.8 12.06| Comparison of Typical Tower flow and Fills | | | |
| :---: | :---: | :---: | :---: |
| Water Flow in tower: $\sim 13000$ $=16000 \mathrm{m3} / \mathrm{hr}$ <br> Temp. of Cold Water* $: \sim \mathbf{3 0 . 0 - 3 3 . 0 ^ { \circ }} \mathrm{C}$ <br> Temp. of Hot Water* $: \sim \mathbf{4 0 . 0 - 4 2 . 0 ^ { \circ } \mathrm { C }}$ <br> Temp. of Wet Bulb $: \sim \mathbf{2 6 . 0 - 2 8 . 0 ^ { \circ } \mathrm { C }}$ <br> No. of Towers (Cells) $: \mathbf{2 - 3}$ | | | |
| | Counter Flow Film Fill | Counter Flow Splash Fill | Cross- <br> Flow <br> Splash <br> Fill |
| Area per Cell of Plant | $14.1 \times 14.1$ | $\begin{gathered} 14.0 \times \\ 14.1 \\ \hline \end{gathered}$ | $\begin{gathered} 2.63 \times \\ 5.50 \\ \hline \end{gathered}$ |
| Fill's Height, Meter | 1.5-1.6 | 5.2 | 11.0 |
| Number of Cells/Tower | 8 | 6 | 5-6 |
| Motor Terminal/Tower power, kWh | $\sim 253$ | $\sim 310$ | $\sim 330$ |
| Pumping Head (static), in meter | 7.3 | 10.8 | 12.06 |
(Cold Water - inlet water, Hot Water - outlet water) （冷水 - 进水，热水 - 出水）
IV. Cooling Tower Types and classification IV. 冷却塔的种类和分类
The cooling towers are dry and wet types, they can open or closed circuited, defined on the principle of working - 冷却塔有干式和湿式两种，它们可以开式或闭式，根据工作原理定义 -
Mechanical or Forced Draft Cooling Tower: These types of cooling tower require fan to circulate the air into the tower that require high rate of cool water. It operates using motors that run at high speed of more than 1000 rpm to feed air and water. 机械或强制通风冷却塔：这些类型的冷却塔需要风扇将空气循环到需要高冷却率的塔中。它使用以超过 1000 rpm 的高速运行的电机运行，以供应空气和水。
Natural Draft Cooling Tower: These types don’t require fan, the heated air is enclosed in the chimney which creates a pressure difference, due to which cool air enters in to the tower. Cooling towers are further categorized into: 自然通风冷却塔：这些类型不需要风扇，加热的空气被封闭在烟囱中，从而产生压差，因此冷空气进入塔。冷却塔进一步分为：
A. Forced draft counter-flow towers A. 强制通风逆流塔
In this type the fan is installed in the lower region on the side of the tower and pushes air into a matrix. Fig 4 shows schema of a forced draft counter flow tower. 在这种类型中，风扇安装在塔侧面的下部区域，并将空气推入矩阵中。图 4 显示了强制通风逆流塔的方案。
Fig. 4. Forced draft counter flow mechanism tower (fan placed at the lower side) 图 4.强制通风逆流机构塔（风扇配置在下侧）
B. Induced-draft counter-flow towers B. 引风逆流塔
In this type the fan is on top and pulls air into a matrix onto which is sprayed the incoming warm water to be cooled. The airflow goes up while water flow goes down, hence counter- 在这种类型中，风扇位于顶部，将空气吸入基质中，将进入的温水喷洒到基质上进行冷却。气流上升，而水流下降，因此逆流
flow. The fans for these tend to be larger but lower horsepower and are larger than forced-draft towers. These can include towers with or without fills as well as single or double flow cooling towers. Fig. 5 shows various induced-draft towers 流。这些的风扇往往更大但马力更低，并且比强制通风塔大。这些可以包括带或不带填料的塔，以及单流或双流冷却塔。图 5 显示了各种诱导通风塔
Fig. 5. Type of induced-draft cooling towers 图 5.引风冷却塔类型
C. Hyperbolic counter flow/Parabolic Towers C. 双曲线逆流/抛物线塔
These are the large vase-shaped concrete towers usually associated with nuclear power plants. They operate on a principle of surface evaporation with natural draft. Air is drawn in by stack effect, (no fan is needed- this is reliable!) and cools by more passive evaporation [9]. Building cost of hyperbolic towers is costly but the operating cost of such towers is low. Various types of cooling tower are shown in Fig. 4-6 respectively. [10] 这些是通常与核电站相关的大型花瓶形混凝土塔。它们的工作原理是自然通风的表面蒸发。空气通过烟囱效应吸入（不需要风扇 - 这是可靠的！），并通过更多的被动蒸发冷却 [9]。双曲塔的建造成本很高，但这种塔的运营成本很低。各种类型的冷却塔分别如图 4-6 所示。[10]
Cooling tower is basically used to eliminate the waste heat from the atmosphere by cooling the water stream at low temperature. This Process is done via evaporation process. 冷却塔基本上是通过在低温下冷却水流来消除大气中的废热。该工艺通过蒸发过程完成。
There are four types of losses in cooling tower. 冷却塔有四种类型的损失。
1. Evaporation loss [11] 1. 蒸发损失 [11]
Evaporation Loss (EL)=0.00086 xx1.79 xx(E L)=0.00086 \times 1.79 \times Circulation Rate ( m3//hr\mathrm{m} 3 / \mathrm{hr} ) x (T1-T2) m3/hr 蒸发损失 (EL)=0.00086 xx1.79 xx(E L)=0.00086 \times 1.79 \times 循环速率 （ m3//hr\mathrm{m} 3 / \mathrm{hr} ） x （T1-T2） m3/hr
here (( T1-T2 )=)= inlet-outlet water temp. difference. 这里 (( T1-T2 )=)= 进出水温度差。
2. Blow down loss 2. 排污损失
Blow Down Loss= Evaporation Loss / (COC. -1)) 排污损失 = 蒸发损失 / （COC. -1 ))
3. Drift loss 3. 漂移损失
4. Heat Load 4. 热负荷
VI. Application of Cooling Towers VI. 冷却塔的应用
The cooling towers have a diverse application in many industrial or commercial uses such as nuclear reactors, gas plants, water-cooled air compressor, and biogas plants, Industrial Hydraulic Oil Coolers & Press, etc. Many petrochemical industries, thermal power stations, oil refineries, etc utilise cooling towers for many of their cooling operations. 冷却塔在许多工业或商业用途中有着多样化的应用，如核反应堆、燃气厂、水冷空气压缩机和沼气厂、工业液压油冷却器和压力机等。许多石化工业、火力发电厂、炼油厂等都使用冷却塔进行许多冷却作。
A nuclear reactor is a device in which controlled nuclear fission takes place. Nuclear fission releases lots of energy, most of which is in the form of kinetic energy (heat). This heat energy is used in making steam, which is used to spin a turbine for generating electricity. After passing through the turbine, the steam must be condensed back into water. Water used for the condensation is in turn cooled for re-use. This water is discharged into large water bodies, cooling pond, or water basin of cooling tower. The steam seen rising from a cooling tower is the heat being released into the environment in the form of steam [6]. 核反应堆是一种发生受控核裂变的装置。核裂变释放出大量能量，其中大部分以动能（热）的形式存在。这种热能用于制造蒸汽，蒸汽用于旋转涡轮机以发电。蒸汽通过涡轮机后，必须冷凝回水中。用于冷凝的水反过来冷却以供重新使用。这些水被排放到大型水体、冷却池或冷却塔的水池中。从冷却塔中升起的蒸汽是以蒸汽的形式释放到环境中的热量 [6]。
A. Civil aspect of Cooling Tower A. 冷却塔的土木方面
The concept of shatterproof super-large concrete cooling tower building in China currently reached a maximum height of upto 250 m and weighing around a hundred twenty, thousand tons. In such towers, the diameter of the base is beyond 180 meters and shell’s structure with a min. thickness of just 0.35 meter. They’re the most significant thin-walled structures within the cooling system till now. Generally the cooling towers of nuclear reactor energy plant measure an allotted a short distance forming nuclear islands for operation. Mostly the constructional instability, for example, collapsing, structural faults, etc. of cooling towers that occur due to vigorous unstable activities that result in vigorous ground level vibrations, that have an effect the operational safety of a nuclear facility, and sometimes produce harmful secondary effects. 中国的防碎超大型混凝土冷却塔建筑的概念目前最高高度可达 250 米，重约 12 万吨。在这样的塔中，底座的直径超过 180 米，壳体结构的最小厚度仅为 0.35 米。到目前为止，它们是冷却系统中最重要的薄壁结构。通常，核反应堆能源厂的冷却塔测量一小段距离，形成核岛以供运行。主要是由于剧烈的不稳定活动导致剧烈的地面振动而发生的冷却塔的结构不稳定性，例如坍塌、结构故障等，这些活动会影响核设施的运行安全，有时还会产生有害的二次影响。
Thus, it is of quite importance to identify the collapsing mode or any failure instrument related to cooling towers. Weaker parts of the extra-large cooling towers are prone to earthquakes or other form of vigorous ground vibrations. Elasto-plastic time history analysis or Iso-parameterized limited time integration dynamic analysis is usually performed on imitation element model of the cooling towers to verify the structural and design strength. 因此，识别与冷却塔相关的坍塌模式或任何故障仪器非常重要。超大型冷却塔的较弱部分容易受到地震或其他形式的剧烈地面振动的影响。通常对冷却塔的仿单元模型进行弹塑性时程分析或等参数化有限时间积分动态分析，以验证结构和设计强度。
The famous Ferry bridge incident in 1965 that reported collapsing of 3 cooling towers which was principally due to the ignorant wind forces and insufficient style concepts, by the structure engineers that lead to the concurrent effects of the wind forces. Thereafter, in depth analysis were performed on the wind forces relating to tower surfaces and wind pressure exerted on the tower were taken into consideration since then. A shaking table test was conducted by Qian et al. [12, 13] which was performed on a super large cooling tower constructed of 1//551 / 55 scale toughened concrete. Different consequent structural dynamic responses were analysed and calculated on the basis of different levels of seismic actions. Any structure weakness, failure instruments related to collapsing mode, etc. was also inspected which could be helpful for determining and designing cooling towers in the future. 1965 年著名的渡口桥事件报告了 3 座冷却塔倒塌，这主要是由于结构工程师无知的风力和风格概念不足，导致了风力的并发效应。此后，对与塔架表面相关的风力进行了深入分析，并从那时起考虑了施加在塔架上的风压。Qian 等 [12， 13] 在由 1//551 / 55 氧化皮加钢混凝土建造的超大型冷却塔上进行了振动台测试。根据不同级别的地震作用分析和计算了不同的后续结构动力响应。还检查了任何结构弱点、与倒塌模式相关的失效工具等，这可能有助于确定和设计未来的冷却塔。
VII. Conclusion VII. 结论
Cooling tower operates based on the control algorithm preprogrammed in the chiller control system. The control 冷却塔根据冷水机组控制系统中预编程的控制算法运行。控件
