Anggota Kelompok : Yowanda Riski Khaidir Amar Husin Yana Merdeka Wati Sari Mentari Agustina*

*Training Session on Energy EquipmentCooling Towers

Presentation from the Energy Efficiency Guide for Industry in Asia

www.energyefficiencyasia.org UNEP 2006Electrical Equipment/Cooling Towers

* UNEP 2006Training Agenda: Cooling TowersIntroductionTypes of cooling towersAssessment of cooling towersEnergy efficiency opportunitiesElectrical Equipment/Cooling Towers

* UNEP 2006IntroductionMain Features of Cooling TowersElectrical Equipment/Cooling Towers(Pacific Northwest National Library, 2001)

* UNEP 2006IntroductionFrame and casing: support exterior enclosuresFill: facilitate heat transfer by maximizing water / air contactSplash fillFilm fillCold water basin: receives water at bottom of towerComponents of a cooling towerElectrical Equipment/Cooling Towers

* UNEP 2006IntroductionDrift eliminators: capture droplets in air streamAir inlet: entry point of airLouvers: equalize air flow into the fill and retain water within towerNozzles: spray water to wet the fillFans: deliver air flow in the towerComponents of a cooling towerElectrical Equipment/Cooling Towers

* UNEP 2006Training Agenda: Cooling TowersIntroductionTypes of cooling towersAssessment of cooling towersEnergy efficiency opportunitiesElectrical Equipment/Cooling Towers

* UNEP 2006Types of Cooling TowersHot air moves through towerFresh cool air is drawn into the tower from bottomNo fan requiredConcrete tower

* UNEP 2006Types of Cooling TowersNatural Draft Cooling TowersElectrical Equipment/Cooling Towers(Gulf Coast Chemical Commercial Inc.)

* UNEP 2006Types of Cooling TowersLarge fans to force air through circulated waterWater falls over fill surfaces: maximum heat transferCooling rates depend on many parametersLarge range of capacitiesCan be grouped, e.g. 8-cell towerMechanical Draft Cooling TowersElectrical Equipment/Cooling Towers

* UNEP 2006Types of Cooling TowersThree typesForced draftInduced draft cross flowInduced draft counter flowMechanical Draft Cooling TowersElectrical Equipment/Cooling Towers

* UNEP 2006Types of Cooling TowersAir blown through tower by centrifugal fan at air inletAdvantages: suited for high air resistance & fans are relatively quietDisadvantages: recirculation due to high air-entry and low air-exit velocitiesForced Draft Cooling TowersElectrical Equipment/Cooling Towers(GEO4VA)

* UNEP 2006Types of Cooling TowersTwo types Cross flow Counter flowAdvantage: less recirculation than forced draft towersDisadvantage: fans and motor drive mechanism require weather-proofinhInduced Draft Cooling TowersElectrical Equipment/Cooling Towers

* UNEP 2006Types of Cooling TowersHot water enters at the topAir enters at bottom and exits at topUses forced and induced draft fansInduced Draft Counter Flow CTElectrical Equipment/Cooling Towers(GEO4VA)

* UNEP 2006Types of Cooling TowersWater enters top and passes over fillAir enters on one side or opposite sidesInduced draft fan draws air across fillInduced Draft Cross Flow CTElectrical Equipment/Cooling Towers(GEO4VA)

* UNEP 2006Training Agenda: Cooling TowersIntroductionTypes of cooling towersAssessment of cooling towersEnergy efficiency opportunitiesElectrical Equipment/Cooling Towers

* UNEP 2006Assessment of Cooling TowersMeasured ParametersElectrical Equipment/Cooling TowersWet bulb temperature of airDry bulb temperature of airCooling tower inlet water temperatureCooling tower outlet water temperatureExhaust air temperatureElectrical readings of pump and fan motorsWater flow rateAir flow rate

* UNEP 2006Performance ParametersElectrical Equipment/Cooling TowersRangeApproachEffectivenessCooling capacityEvaporation lossCycles of concentrationBlow down lossesLiquid / Gas ratioAssessment of Cooling Towers

* UNEP 2006 1. RangeElectrical Equipment/Cooling TowersDifference between cooling water inlet and outlet temperature:

Range (C) = CW inlet temp CW outlet temp

High range = good performanceAssessment of Cooling Towers

* UNEP 2006 2. ApproachElectrical Equipment/Cooling TowersDifference between cooling tower outlet cold water temperature and ambient wet bulb temperature:

Approach (C) = CW outlet temp Wet bulb temp

Low approach = good performanceAssessment of Cooling Towers

* UNEP 20063. EffectivenessElectrical Equipment/Cooling TowersEffectiveness in %= Range / (Range + Approach) = 100 x (CW temp CW out temp) / (CW in temp Wet bulb temp)High effectiveness = good performanceAssessment of Cooling Towers

* UNEP 20064. Cooling CapacityElectrical Equipment/Cooling TowersHeat rejected in kCal/hr or tons of refrigeration (TR)= mass flow rate of water X specific heat X temperature differenceHigh cooling capacity = good performanceAssessment of Cooling Towers

* UNEP 20065. Evaporation LossElectrical Equipment/Cooling TowersWater quantity (m3/hr) evaporated for cooling duty= theoretically, 1.8 m3 for every 10,000,000 kCal heat rejected

= 0.00085 x 1.8 x circulation rate (m3/hr) x (T1-T2)

T1-T2 = Temp. difference between inlet and outlet waterAssessment of Cooling Towers

* UNEP 20066. Cycles of concentration (C.O.C.)Electrical Equipment/Cooling TowersRatio of dissolved solids in circulating water to the dissolved solids in make up waterDepend on cycles of concentration and the evaporation losses

Blow Down = Evaporation Loss / (C.O.C. 1)7. Cycles of concentration (C.O.C.)Assessment of Cooling Towers

* UNEP 20068. Liquid Gas (L/G) RatioElectrical Equipment/Cooling TowersRatio between water and air mass flow ratesHeat removed from the water must be equal to the heat absorbed by the surrounding airL(T1 T2) = G(h2 h1)L/G = (h2 h1) / (T1 T2)

T1 = hot water temp (oC)T2 = cold water temp (oC)Enthalpy of air water vapor mixture at inlet wet bulb temp (h1) and outlet wet bulb temp (h2)Assessment of Cooling Towers

* UNEP 2006Training Agenda: Cooling TowersIntroductionTypes of cooling towersAssessment of cooling towersEnergy efficiency opportunitiesElectrical Equipment/Cooling Towers

* UNEP 2006Energy Efficiency OpportunitiesElectrical Equipment/Cooling TowersSelecting a cooling towerFillsPumps and water distributionFans and motors

* UNEP 2006Energy Efficiency Opportunities1. Selecting a cooling towerElectrical Equipment/Cooling TowersCapacityHeat dissipation (kCal/hour)Circulated flow rate (m3/hr)Other factors

* UNEP 2006Energy Efficiency OpportunitiesElectrical Equipment/Cooling TowersRange Range determined by process, not by system

Approach Closer to the wet bulb temperature = Bigger size cooling tower = More expensive1. Selecting a cooling tower

* UNEP 2006Energy Efficiency OpportunitiesElectrical Equipment/Cooling TowersHeat LoadDetermined by processRequired cooling is controlled by the desired operating temperatureHigh heat load = large size and cost of cooling tower1. Selecting a cooling tower

* UNEP 2006Energy Efficiency OpportunitiesElectrical Equipment/Cooling TowersWet bulb temperature considerations:Water is cooled to temp higher than wet bulb tempConditions at tower siteNot to exceed 5% of design wet bulb tempIs wet bulb temp specified as ambient (preferred) or inletCan tower deal with increased wet bulb tempCold water to exchange heat1. Selecting a cooling tower

* UNEP 2006Energy Efficiency OpportunitiesElectrical Equipment/Cooling TowersRelationship range, flow and heat loadRange increases with increased Amount circulated water (flow) Heat loadCauses of range increase Inlet water temperature increases Exit water temperature decreasesConsequence = larger tower1. Selecting a cooling tower

* UNEP 2006Energy Efficiency OpportunitiesElectrical Equipment/Cooling TowersRelationship Approach and Wet bulb temperatureIf approach stays the same (e.g. 4.45 oC)Higher wet bulb temperature (26.67 oC)= more heat picked up (15.5 kCal/kg air)= smaller tower neededLower wet bulb temperature (21.11 oC)= less heat picked up (12.1 kCal/kg air)= larger tower needed1. Selecting a cooling tower

* UNEP 2006Energy Efficiency OpportunitiesElectrical Equipment/Cooling TowersHot water distributed over fill media and cools down through evaporationFill media impacts electricity useEfficiently designed fill media reduces pumping costsFill media influences heat exchange: surface area, duration of contact, turbulence2. Fill media

* UNEP 2006Energy Efficiency OpportunitiesElectrical Equipment/Cooling TowersComparing 3 fill media: film fill more efficient2. Fill media(BEE India, 2004; Ramarao; and Shivaraman)

Splash FillFilm FillLow Clog Film FillPossible L/G Ratio1.1 1.51.5 2.0 1.4 1.8Effective Heat Exchange Area30 45 m2/m3150 m2/m385 - 100 m2/m3Fill Height Required5 10 m1.2 1.5 m1.5 1.8 mPumping Head Requirement9 12 m5 8 m6 9 mQuantity of Air RequiredHighMuch LowLow

* UNEP 2006Energy Efficiency Opportunities3. Pumps and water distributionElectrical Equipment/Cooling TowersPumps: see pumps sessionOptimize cooling water treatmentIncrease cycles of concentration (COC) by cooling water treatment helps reduce make up waterIndirect electricity savingsInstall drift eliminatorsReduce drift loss from 0.02% to only 0.003 0.001%

* UNEP 2006Energy Efficiency Opportunities4. Cooling Tower FansElectrical Equipment/Cooling TowersFans must overcome system resistance, pressure loss: impacts electricity useFan efficiency depends on blade profile Replace metallic fans with FBR blades (20-30% savings)Use blades with aerodynamic profile (85-92% fan efficiency)

*Training Session on Energy EquipmentCooling Towers

THANK YOUFOR YOU ATTENTION

UNEP 2006Electrical Equipment/Cooling Towers

* UNEP 2006Disclaimer and ReferencesElectrical Equipment/Cooling TowersThis PowerPoint training session was prepared as part of the project Greenhouse Gas Emission Reduction from Industry in Asia and the Pacific (GERIAP). While reasonable efforts have been made to ensure that the contents of this publication are factually correct and properly referenced, UNEP does not accept responsibility for the accuracy or completeness of the contents, and shall not be liable for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the contents of this publication. UNEP, 2006.The GERIAP project was funded by the Swedish International Development Cooperation Agency (Sida)Full references are included in the textbook chapter that is available on www.energyefficiencyasia.org

*TO THE TRAINERThis PowerPoint presentation can be used to train people about the basics of cooling towers. The information on the slides is the minimum information that should be explained. The trainer notes for each slide provide more detailed information, but it is up to the trainer to decide if and how much of this information is presented also.

Additional materials that can be used for the training session are available on www.energyefficiencyasia.org under Energy Equipment and include:Textbook chapter on this energy equipment that forms the basis of this PowerPoint presentation but has more detailed informationQuiz ten multiple choice questions that trainees can answer after the training sessionWorkshop exercise a practical calculation related to this equipmentOption checklist a list of the most important options to improve energy efficiency of this equipmentCompany case studies participants of past courses have given the feedback that they would like to hear about options implemented at companies for each energy equipment. More than 200 examples are available from 44 companies in the cement, steel, chemicals, ceramics and pulp & paper sectors

Untuk pelatih :Presentasi PowerPoint ini dapat digunakan untuk melatih orang-orang tentang dasar-dasar menara pendingin. Informasi pada slide adalah informasi minimum yang harus dijelaskan. Catatan pelatih untuk setiap slide memberikan informasi yang lebih rinci, tapi terserah kepada pelatih untuk memutuskan apakah dan seberapa banyak informasi ini disajikan juga.

Bahan tambahan yang dapat digunakan untuk sesi latihan tersedia di www.energyefficiencyasia.org di bawah Energy Equipment dan termasuk :Textbook chapter Pada energy equipment ini yang membentuk dasar dari presentasi PowerPoint ini tapi memiliki lebih banyak informasi yang lebih rinci.Quiz Sepuluh pertanyaan pilihan ganda yang dapat dijawab oleh peserta setelah sesi latihan.Workshop exercise Perhitungan praktis yang berhubungan dengan peralatan ini.Option checklist Daftar pilihan yang paling penting untuk meningkatkan efisiensi energi peralatan ini.Company case studies Peserta dari kursus yang telah lalu memberikan umpan balik bahwa mereka ingin mendengar tentang opsi yang diterapkan di perusahaan untuk setiap peralatan energi. Lebih dari 200 contoh yang ada dari 44 perusahaan semen, baja, bahan kimia, keramik, dan sektor pulpen & kertas.

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*Cooled water is needed for, for example, air conditioners, manufacturing processes or power generation. A cooling tower is an equipment used to reduce the temperature of a water stream by extracting heat from water and emitting it to the atmosphere. This figure shows a cooling tower. Cooling towers make use of evaporation whereby some of the water is evaporated into a moving air streamand subsequently discharged into the atmosphere. As a result, the remainder of the water is cooled down significantly (Figure 1). Cooling towers are able to lower the water temperatures more than devices that use only air to reject heat, like the radiator in a car, and are therefore more cost-effective and energy efficient.

Air dingin diperlukan untuk, misalnya, AC, proses manufaktur atau pembangkit listrik.Menara pendingin adalah peralatan yang digunakan untuk mengurangi suhu aliran air dengan cara mengekstraksi panas dari air dan memancarkannya ke atmosfer.Gambar ini memperlihatkan sebuah menara pendingin. Cooling towers memanfaatkan penguapan dimana sebagian air menguap ke dalam aliran udara yang bergerakdan kemudian dibuang ke atmosfer.Sebagai hasilnya, sisa air didinginkan secara signifikan (Gambar 1). Menara pendingin mampu menurunkan suhu air lebih dari perangkat yang hanya menggunakan udara untuk membuang panas, seperti radiator di mobil, dan karena itu lebih hemat biaya dan hemat energi.*Frame and casing. Most towers have structural frames that support the exterior enclosures (casings), motors, fans, and other components. With some smaller designs, such as some glass fiber units, the casing may essentially be the frame.Fill. Most towers employ fills (made of plastic or wood) to facilitate heat transfer by maximizing water and air contact. There are two types of fill: Splash fill: water falls over successive layers of horizontal splash bars, continuously breaking into smaller droplets, while also wetting the fill surface. Plastic splash fills promote better heat transfer than wood splash fills. Film fill: consists of thin, closely spaced plastic surfaces over which the water spreads, forming a thin film in contact with the air. These surfaces may be flat, corrugated, honeycombed, or other patterns. The film type of fill is the more efficient and provides same heat transfer in a smaller volume than the splash fill.Cold-water basin. The cold-water basin is located at or near the bottom of the tower, and it receives the cooled water that flows down through the tower and fill. The basin usually has a sump or low point for the cold-water discharge connection. In many tower designs, the cold-water basin is beneath the entire fill. In some forced draft counter flow design, however, the water at the bottom of the fill is channeled to a perimeter trough that functions as the cold-water basin. Propeller fans are mounted beneath the fill to blow the air up through the tower. With this design, the tower is mounted on legs, providing easy access to the fans and their motors.

Frame and casing. Kebanyakan menara memiliki rangka struktural yang menunjang penutup luar, mesin, kipas, dan komponen lainnya. Dengan beberapa desain yang lebih kecil, seperti beberapa unit fiber glass, penutupnya mungkin akan secara alami menjadi frame/rangka.Fill. Kebanyakan menara menggunakan bahan pengisi (terbuat dari plastik atau kayu) untuk memfasilitasi perpindahan panas dengan memaksimalkan air dan kontak udara. Ada dua jenis pengisian :Splash fill: air jatuh berturut-turut pada lapisan bar percikan horizontal, secara terus menerus membuat tetesan-tetesan kecil, juga membasahi permukaan pengisi. Pengisi percikan plastik mendorong perpindahan panas lebih baik dari pada pengisi percikan kayu.Film fill: terdiri dari permukaan plastik tipis dengan jarak yang berdekatan dimana diatasnya tersebar air, membentuk lapisan tipis saat kontak dengan udara. Permukaan ini dapat berbentuk datar, bergelombang, berlekuk, atau pola lainnya. Jenis film fill lebih efisien dan menyediakan perpindahan panas yang sama dalam volume yang lebih kecil daripada splash fill.Cold-water basin. Kolam air dingin terletak di atau dekat bagian bawah menara, dan menerima air dingin yang mengalir turun melalui menara dan mengisi. Kolam biasanya memiliki lubang atau titik terendah untuk pengeluaran air dingin. Dalam beberapa desain, kolam air dingin berada dibagian bawah seluruh isi. Dalam beberapa desain aliran yang berlawanan arah pada forced draft, air di bagian bawah pengisi disalurkan ke bak yang berbentuk lingkaran yang berfungsi sebagai kolam air dingin. Kipas baling-baling dipasang di bawah pengisi untuk dapat meniupkan udara melalui menara. Dengan desain ini, menara dipasang pada kaki, menyediakan akses mudah ke kipas dan mesinnya.*Drift eliminators. These capture water droplets entrapped in the air stream that otherwise would be lost to the atmosphere. Air inlet. This is the point of entry for the air entering a tower. The inlet may take up an entire side of a tower (cross-flow design) or be located low on the side or the bottom of the tower (counter-flow design).Louvers. Generally, cross-flow towers have inlet louvers. The purpose of louvers is to equalize air flow into the fill and retain the water within the tower. Many counter flow tower designs do not require louvers.Nozzles. These spray water to wet the fill. Uniform water distribution at the top of the fill is essential to achieve proper wetting of the entire fill surface. Nozzles can either be fixed and spray in a round or square patterns, or they can be part of a rotating assembly as found in some circular cross-section towers.Fans. Both axial (propeller type) and centrifugal fans are used in towers. Generally, propeller fans are used in induced draft towers and both propeller and centrifugal fans are found in forced draft towers. Depending upon their size, the type of propeller fans used is either fixed or variable pitch. A fan with non-automatic adjustable pitch blades can be used over a wide kW range because the fan can be adjusted to deliver the desired air flow at the lowest power consumption. Automatic variable pitch blades can vary air flow in response to changing load conditions.

Drift eliminators. Tangkapan tetesan air tersebut terperangkap dalam aliran udara yang akan hilang ke atmosfer. Air inlet. Ini adalah titik masuk bagi udara untuk memasuki menara. Jalan masuk dapat diambil dari seluruh sisi menara (desain aliran silang) atau berada rendah di samping atau bagian bawah menara (desain aliran berlawanan arah).Louvers. Umumnya, menara dengan aliran silang memiliki kisi-kisi jalan masuk. Tujuan dari kisi-kisi ini adalah untuk menyamakan aliran udara ke dalam pengisi dan mempertahankan air dalam menara. Banyak desain menara aliran yang berlawanan arah tidak memerlukan kisi-kisi. Nozzles. semprotan air ini untuk membasahi pengisi. Distribusi air di bagian atas pengisi sangat penting untuk mencapai pembasahan yang tepat dari seluruh permukaan pengisi. Nozzles dapat tetap dan disemprotkan di putaran atau pola persegi, atau dapat juga menjadi bagian dari perakitan berputar seperti yang ditemukan di beberapa menara penampang melingkar.Fans. kedua aksial (tipe baling-baling)dan kipas sentrifugal digunakan pada menara. Umumnya, kipas baling-baling digunakan pada menara induced draft, dan kipas baling-baling dan kipas sentrifugal keduanya digunakan pada menara forced draft. Tergantung pada ukurannya, jenis kipas baling-baling yang digunakan dapat tetap atau variabel pitch. Sebuah kipas dengan baling-baling yang disesuaikan non otomatis dapat digunakan pada berbagai macam kW karena kipas tersebut dapat disesuaikan untuk memberikan aliran udara yang diinginkan pada konsumsi daya terendah. Automatic variable pitch blades dapat merubah aliran udara dalam menanggapi perubahan kondisi beban. *We will now look at the two main types of cooling towers: the natural draft and mechanical draft cooling towers.

Sekarang kita akan melihat dua jenis utama menara pendingin : the natural draft and mechanical draft cooling towers.*The natural draft or hyperbolic cooling tower makes use of the difference in temperature between the ambient air and the hotter air inside the tower. It works as follows:Hot air moves upwards through the tower (because hot air rises)Fresh cool air is drawn into the tower through an air inlet at the bottom. Due to the layout of the tower, no fan is required and there is almost no circulation of hot air that could affect the performance. Concrete is used for the tower shell with a height of up to 200 m. These cooling towers are mostly only for large heat duties because large concrete structures are expensive.

The natural draft atau menara pendingin hiperbola menggunakan perbedaan suhu antara suhu lingkungan dengan udara panas di dalam menara. Dengan cara kerja sebagai berikut :Udara panas bergerak ke atas melalui menara (karena udara panas naik)Udara sejuk segar ditarik ke dalam menara melalui jalan masuk udara di bagian bawah. karena tata letak menara, tidak diperlukan kipas dan hampir tidak ada sirkulasi udara panas yang dapat mempengaruhi kinerja. Beton digunakan untuk dinding menara dengan ketinggian hingga 200 m. Menara pendingin ini kebanyakan hanya digunakan untuk tanggung jawab yang besar karena struktur beton besar yang mahal.

*There are two main types of natural draft towers:(Click once) Cross flow tower (left figure): air is drawn across the falling water and the fill is located outside the tower(Click once) Counter flow tower (right figure): air is drawn up through the falling water and the fill is therefore located inside the tower, although design depends on specific site conditions

Ada dua jenis utama menara natural draft:Click once) Menara aliran silang (gambar kiri): udara di tarik pada air yang jatuh dan pengisi berada di luar menara.(Click once) Menara aliran berlawanan (gambar kanan): udara ditarik melalui air yang jatuh dan pengisi terletak di dalam menara, walaupun desain tergantung pada kondisi situs tertentu*Mechanical draft towers have large fans to force or draw air through circulated water. The water falls downwards over fill surfaces, which help increase the contact time between the water and the air - this helps maximize heat transfer between the two. Cooling rates of mechanical draft towers depend upon various parameters such as fan diameter and speed of operation, fills for system resistance etc.Mechanical draft towers are available in a large range of capacities. Towers can be either factory built or field erected for example concrete towers are only field erected.Many towers are constructed so that they can be grouped together to achieve the desired capacity. Thus, many cooling towers are assemblies of two or more individual cooling towers or cells. The number of cells they have, e.g., a eight-cell tower, often refers to such towers.

Mechanical draft towers memiliki kipas yang besar untuk mendorong atau mengalirkan udara melalui edaran air. Air jatuh ke bawah permukaan pengisi, yang membantu meningkatkan kontak antara air dan udara - ini membantu memaksimalkan perpindahan panas antara keduanya.Tingkat pendinginan mechanical draft towers tergantung pada berbagai parameter seperti diameter kipas dan kecepatan operasi, sistem ketahanan pengisi, dll.Mechanical draft towers tersedia dalam berbagai macam kapasitas. Menara dapat berupa buatan pabrik atau didirikan di lapangan sebagai contoh menara beton didirikan di lapangan. Banyak menara dibangun sehingga mereka dapat dikelompokkan bersama-sama untuk mencapai kapasitas yang diinginkan. Dengan demikian, banyak menara pendingin yang merupakan rakitan dari dua atau lebih menara pendingin individu atau "sel.Jumlah sel yang mereka miliki, misalnya, sebuah menara delapan sel, sering mengacu pada menara tersebut.*We will now explain three types of mechanical draft cooling towers, and the advantages and disadvantages of each.

Sekarang kita akan menjelaskan tiga jenis rancangan mekanik menara pendingin, dan keuntungan dan kerugian dari masing-masingnya.*Forced draft cooling towerHow it works: air is blown through the tower by a fan located in the air inletAdvantages: Suited for high air resistance due to centrifugal blower fansFans are relatively quiet Disadvantages: Recirculation due to high air-entry and low air-exit velocities, which can be solved by locating towers in plant rooms combined with discharge ducts

Forced draft cooling towerCara kerjaanya: udara ditiup melalui menara oleh kipas yang terletak di jalan masuk.Keuntungan: Cocok untuk resistansi udara tinggi karena kipas peniup sentrifugalKipas relatif cukupKerugian: resirkulasi karena kecepatan udara masuk tinggi dan udara keluar rendah, yang dapat di selesaikan dengan menempatkan menara di ruang pabrik dan di gabungkan dengan saluran pembuangan.*Two types of induced draft cooling towers: cross flow and counter flowAdvantage: Less recirculation than forced draft towers because the speed of exit air is 3-4 times higher than entering air Disadvantage: Fans and the motor drive mechanism require weather-proofing against moisture and corrosion because they are in the path of humid exit air

Dua jenis induced draft cooling towers: aliran silang dan aliran berlawanan arah.Keuntungan : resirkulasi lebih sedikit dari forced draft towers karena kecepatanudara keluar 3-4 kali lebih tinggi dari udara masukKerugian : kipas dan mekanisme penggerak mesin memerlukan tahan kelembaban dan korosi karena mereka berada dalam jalur udara keluar lembab.*Induced draft counter flow cooling towerhot water enters at the topair enters bottom and exits at the top uses forced and induced draft fans

Induced draft counter flow cooling towerUdara panas masuk di bagian atasUdara memasuki bagian bawah dan keluar di bagian atasMenggunakan forced dan kipas induced draft*Induced draft cross flow cooling tower: water enters at top and passes over fillair enters on one side (single-flow tower) or opposite sides (double-flow tower)an induced draft fan draws air across fill towards exit at top of tower

Induced draft cross flow cooling tower: Air masuk di bagian atas dan melewati pengisiUdara masuk dari satu sisi (menara aliran tunggal) atau dari sisi yang berlawanan (menara aliran ganda)Induced draft fan menarik udara di pengisi menuju keluar di bagian atas menara

*Performance evaluation.

Evaluasi kinerja.

*The performance of cooling towers is evaluated to assess present levels of approach and range against their design values, identify areas of energy wastage and to suggest improvements. During the performance evaluation, portable monitoring instruments are used to measure the following parameters:Wet bulb temperature of airDry bulb temperature of airCooling tower inlet water temperatureCooling tower outlet water temperatureExhaust air temperatureElectrical readings of pump and fan motorsWater flow rateAir flow rate

Kinerja menara pendingin dievaluasi untuk menilai tingkat pendekatan dan jangkauan terhadap nilai desain, mengidentifikasi area terjadinya pemborosan energi dan untuk memberikan saran perbaikan. Selama evaluasi kinerja, peralatan pemantauan yang portable digunakan untuk mengukur parameter berikut:Suhu basah udaraSuhu kering udaraMenara pendingin suhu air masukMenara oendingin suhu air keluarSuhu udara pipa pembuanganBacaan listrik dari pompa dan mesin kipasLaju aliran airLaju aliran udara*These measured parameters and then used to determine the cooling tower performance in several ways. These are:RangeApproachEffectivenessCooling capacityEvaporation lossCycles of concentrationBlow down lossesLiquid / Gas ratioWe will now go through each of these parameters on the next slides

Parameter ini diukur dan kemudian digunakan untuk menentukan kinerja menara pendingin dalam beberapa cara. Diantaranya adalah :JarakPendekatanEfektivitasKapasitas pendinginKehilangan penguapanSiklus konsentrasiKehilangan peniupan Rasio cair/gasKita sekarang akan melihat masing-masing parameter tersebut pada slide berikutnya*The range is the difference between the cooling tower water inlet and outlet temperature. The formula for cooling tower range in degrees Celcius is cooling water inlet temperature minus cooling water outlet temperatureA high CT Range means that the cooling tower has been able to reduce the water temperature effectively, and is thus performing well.

Jarak adalah perbedaan antara suhu masuk dan suhu keluar.Rumus untuk jarak menara pendingin dalam derajat celcius adalah suhu masuk kurang suhu keluar.Jarak CT yang tinggi berarti menara pendingin telah mampu menurunkan suhu air secara efektif, dan kinerjanya bagus.*Approach is the difference between the cooling tower outlet cold-water temperature and ambient wet bulb temperature. The formula for approach is CT Approach in degrees Celcius is cold water outlet temperature minus the wet bulb temperatureThe lower the approach the better the cooling tower performance. Although, both range and approach should be monitored, the `Approach is a better indicator of cooling tower performance.

Pendekatan merupakan perbedaan antara suhu air dingin menara pendingin dengan suhu lingkungan.Rumus untuk pendekatan dalam derajat selsius adalah suhu keluar air dingin kurang suhu wet bulb.Semakin rendah pendekatan semakin baik kinerja menara pendingin. Meskipun, jarak dan pendekatan keduanya harus di awasi, pendekatan merupakan indikator yang lebih baik dari kinerja menara pendingin.*Cooling tower effectiveness is the ratio between the range and the ideal range (in percentage), i.e. difference between cooling water inlet temperature and ambient wet bulb temperatureEffectiveness = Range / (Range + Approach)The formula for cooling tower effectiveness is: CT Effectiveness (%) = 100 x (CW temp CW out temp) / (CW in temp WB temp)The higher this ratio, the higher the cooling tower effectiveness.

Keefektivan menara pendingin adalah rasio antara jarak dan jarak ideal (dalam persentase), yaitu perbedaan antara suhu air masuk dan suhu lingkungan.Keefektivan = jarak / (jarak + pendekatan)Rumus untuk keefektivan menara pendingin adalah: Efektivitas CT (%) = 100 x (suhu CW - CW keluar temp) / (CW di suhu - suhu WB)Semakin tinggi rasionya semakin tinggi keefektivan menara pendingin.*Cooling capacity is the heat rejected in kCal/hr or tons of refrigeration (TR), given as product of mass flow rate of water, specific heat and temperature difference.

Kapasitas pendingin adalah panas yang dibuang dalam kKal / jam atau ton pendinginan (TR), diberikan sebagai hasil dari kecepatan aliran massa air, panas spesifik dan perbedaan suhu.*Evaporation loss is the water quantity evaporated for cooling duty. Theoretically the evaporation quantity works out to 1.8 m3 for every 1,000,000 kCal heat rejected. The following formula can be used (Perry):Evaporation loss (m3/hr) = 0.00085 x 1.8 x circulation rate (m3/hr) x (T1-T2)T1 - T2 = temperature difference between inlet and outlet water

Kehilangan penguapan adalah jumlah air yang diuapkan untuk tugas pendinginan.Secara teoritis jumlah penguapan mencapai 1,8 m3 untuk setiap panas 1.000.000 kkal yang ditolak.Kehilangan penguapan (m3 / jam) = 0,00085 x 1,8 x laju sirkulasi (m3 / jam) x (T1-T2)T1 - T2 = perbedaan suhu antara air masuk dan keluar*Cycles of concentration, C.O.C, is the ratio of dissolved solids in circulating water to the dissolved solids in make up water.(Click once) Blow down losses depend upon cycles of concentration and the evaporation losses.Blow down losses is given by the following relation: Blow down = evaporation loss / (cycles of concentration 1)

Siklus konsentrasi, COC, adalah rasio padatan terlarut dalam sirkulasi air dengan padatan terlarut dalam membuat air(Click once) Kehilangan peniupan tergantung pada siklus konsentrasi dan kehilangan penguapanKehilangan penguapan diberikan oleh hubungan berikut: penguapan = kehilangan penguapan / (siklus konsentrasi - 1)*The L/G ratio of a cooling tower is the ratio between the water and the air mass flow rates. Cooling towers have certain design values, but seasonal variations require adjustment and tuning of water and air flow rates to get the best cooling tower effectiveness. Adjustments can be made by water box loading changes or blade angle adjustments. Thermodynamic rules also dictate that the heat removed from the water must be equal to the heat absorbed by the surrounding air. Therefore the following formulae can be used (mention that these are the same formula, just written differently):L(T1 T2) = G(h2 h1)L/G = (h2 h1) / (T1 T2)Where:L/G = liquid to gas mass flow ratio (kg/kg)T1 = hot water temperature (0C)T2 = cold-water temperature (0C)h2 = enthalpy of air-water vapor mixture at exhaust wet-bulb temperature (same units as above)h1 = enthalpy of air-water vapor mixture at inlet wet-bulb temperature (same units as above)

Rasio L / G menara pendingin adalah rasio antara air dan laju aliran massa udara. Menara pendingin memiliki nilai desain tertentu, namun variasi musiman memerlukan penyesuaian dan tingkat air dan aliran udara untuk mendapatkan keefektivan menara pendingin yang terbaik. Penyesuaian dapat dilakukan dengan perubahan pemuatan kotak air atau penyesuaian sudut blade. Aturan termodinamika juga mengatakan bahwa panas yang dibuang dari air harus sama dengan panas yang diserap oleh udara sekitarnya.Oleh karena itu rumus berikut dapat digunakan (disebutkan bahwa ini adalah rumus yang sama, hanya ditulis berbeda): L(T1 T2) = G(h2 h1)L/G = (h2 h1) / (T1 T2) Where:L/G = rasio aliran massa cair ke gas (kg/kg)T1 = suhu air panas (0C)T2 = suhu air dingin (0C)h2 = entalpi campuran udara dan uap air pada suhu pipa pembuangan uap (unit yang sama dengan yang di atas)h1 = entalpi campuran udara dan uap air pada suhu jalan masuk (unit yang sama dengan yang di atas)

*We will now look at energy efficiency opportunities by exploring the factors that affect the cooling tower performance.

Sekarang kita akan melihat peluang efisiensi energi dengan menjelajahi faktor-faktor yang mempengaruhi kinerja menara pendingin.*The main areas for improving the energy efficiency of cooling towers are:Selecting the right cooling tower (because the structural aspects of the cooling tower cannot be changed after it is installed)FillsPumps and water distribution systemFans and motorsWe will go through these one by one on the next slides.

Area utama untuk meningkatkan efisiensi energi menara pendingin adalah:Pilih menara pendingin yang tepat, (karena aspek struktural menara pendingin tidak dapat diubah setelah diinstal)PengisiPompa dan sistem distribusi airKipas dan mesinKita akan lihat satu persatu di slide berikutnya.*Once a cooling tower is in place it is very difficult to significantly improve its energy performance. A number of factors are of influence on the cooling towers performance and should be considered when choosing a cooling tower: capacity, range, approach, heat load, wet bulb temperature, and the relationship between these factors. We will start with capacity.Capacity, in terms of heat dissipation (in kCal/hour) and circulated flow rate (m3/hr), are an indication of the capacity of cooling towers. However, these design parameters are not sufficient to understand the cooling tower performance. For example, a cooling tower sized to cool 4540 m3/hr through a 13.9 0C range might be larger than a cooling tower to cool 4540 m3/hr through 19.5 0C range. Therefore other design parameters are also needed.

Sekali menara pendingin di tempat yang sangat sulit meningkatkan performa energinya secara signifikan. Sejumlah faktor berpengaruh pada kinerja menara pendingin dan harus dipertimbangkan ketika memilih sebuah menara pendingin: kapasitas, jarak, pendekatan, muatan panas, suhu lembab, dan hubungan antara faktor-faktor ini. Kita mulai dengan kapasitas.Kapasitas, dalam hal pembuangan panas (dalam kKal / jam) dan laju alir tersirkulasi (m3 / jam), merupakan indikasi kapasitas menara pendingin. Namun, parameter desain ini tidak cukup untuk memahami kinerja menara pendingin.Sebagai contoh, menara pendingin untuk mendinginkan kisaran 4540 m3 / jam melalui 13,9 0C mungkin lebih besar dari menara pendingin yang mendinginkan kisaran m3 / jam melalui 19,5 0C. Oleh karena itu parameter desain lainnya juga diperlukan.*Cooling towers are usually specified to cool a certain flow rate from one temperature to another temperature at a certain wet bulb temperature. For example, the cooling tower might be specified to cool 4540 m3/hr from 48.9oC to 32.2oC at 26.7oC wet bulb temperature. When the size of the tower has to be chosen, then the approach is most important, closely followed by the flow rate, and the range and wet bulb would be of lesser importance.

RangeThe range is difference between the cooling tower water inlet and outlet temperature, in this case range 16.7 oC = 48.9 oC - 32.2 oC. The range is thus determined not by the cooling tower, but by the process it is serving.

ApproachThe approach is also important. This is the cold water temp minus the wet bulb temp, in this case Approach (5.50C) = Cold-water temperature 32.2 0C Wet bulb temperature (26.7 0C). As a general rule, the closer the approach to the wet bulb, the more expensive the cooling tower due to increased size. Usually a 2.8oC approach to the design wet bulb is the coldest water temperature that cooling tower manufacturers will guarantee.

Menara pendingin biasanya ditetapkan untuk mendinginkan laju aliran tertentu dari satu suhu ke suhu yang lain pada suhu wet bulb tertentu. Sebagai contoh, menara pendingin bisa ditetapkan untuk mendinginkan 4540 m3 / jam dari 48.9oC ke 32.2oC di 26.7oC suhu wet bulb. Ketika harus memilih ukuran menara,maka pendekatan adalah yang paling penting, diikuti oleh laju alir, dan jangkauan dan wet bulb akan lebih kurang penting.

RangeJarak adalah perbedaan antara air masuk menara pendingin, dalam hal ini berkisar 16.7 oC = 48.9 oC - 32.2 oC. Jarak tidak ditentukan oleh menara pendingin, tapi di tentukan oleh cara penyediaannya.

ApproachPendekatan juga penting. Suhu air dingin kurang suhu wet bulb, dalam hal ini pendekatan (5.50C) = suhu air dingin 32.2 0C suhu Wet bulb (26.7 0C). Sebagai aturan umum, semakin dekat pendekatan terhadap wet bulb, semakin mahal menara pendingin karena meningkatnya ukuran.Biasanya, pendekatan 2.8oC ke terhadap desain wet bulb adalah suhu air terdingin yang akan dijamin oleh produsen menara pendingin.*The heat load imposed on a cooling tower is determined by the process being served. Process heat loads may vary considerably depending upon the process involved and are therefore difficult to determine accurately. On the other hand, air conditioning and refrigeration heat loads can be determined with greater accuracy.The degree of cooling required is controlled by the desired operating temperature of the process. In most cases, a low operating temperature is desirable to increase process efficiency or to improve the quality or quantity of the product. However, in some applications (e.g. internal combustion engines) high operating temperatures are desirable. The size and cost of the cooling tower is increases with increasing heat load. Purchasing undersized equipment (if the calculated heat load is too low) and oversized equipment (if the calculated heat load is too high) is something to be aware of.

Beban panas yang di bebankan pada menara pendingin ditentukan oleh proses penyediaannya.Proses muatan panas dapat bervariasi tergantung pada proses yang terlibat dan oleh karena itu sulit ditentukan secara akurat.Di sisi lain, AC dan beban panas pendinginan dapat ditentukan dengan akurasi yang lebih besar.Tingkat pendinginan yang diperlukan dikontrol oleh suhu operasi yang diinginkan dari proses. Dalam kebanyakan kasus, suhu operasi yang rendah diinginkan untuk meningkatkan efisiensi proses atau untuk meningkatkan kualitas atau kuantitas produk. Namun, dalam beberapa aplikasi (misalnya mesin pembakaran internal) yang diinginkan adalah suhu operasi yang tinggi.Ukuran dan harga menara pendingin meningkat dengan meningkatnya muatan panas. Pembelian peralatan berukuran kecil (jika beban panas yang dihitung terlalu rendah) dan peralatan besar (jika beban panas yang dihitung terlalu tinggi) adalah sesuatu yang harus diperhatikan.*Wet bulb temperature is an important factor in performance of evaporative water cooling equipment, because it is the lowest temperature to which water can be cooled. For this reason, the wet bulb temperature of the air entering the cooling tower determines the minimum operating temperature level throughout the plant, process, or system. The following should be considered when pre-selecting a cooling tower based on the wet bulb temperature:Theoretically, a cooling tower will cool water to the entering wet bulb temperature. In practice, however, water is cooled to a temperature higher than the wet bulb temperature because heat needs to be rejected from the cooling tower. A pre-selection of towers based on the design wet bulb temperature must consider conditions at the tower site. The design wet bulb temperature also should not be exceeded for more than 5 percent of the time. In general, the design temperature selected is close to the average maximum wet bulb temperature in summer. Confirm whether the wet bulb temperature is specified as ambient (the temperature in the cooling tower area) or inlet (the temperature of the air entering the tower, which is often affected by discharge vapors recirculated into the tower). As the impact of recirculation cannot be known in advance, the ambient wet bulb temperature is preferred.Confirm with the supplier if the cooling tower is able to deal with the effects of increased wet bulb temperatures.The cold-water temperature must be low enough to exchange heat or to condense vapors at the optimum temperature level. The quantity and temperature of heat exchanged can be considered when choosing the right size cooling tower and heat exchangers at the lowest costs.

Suhu wet bulb merupakan faktor penting dalam kinerja peralatan penguapan pendingin air, karena itu adalah suhu terendah dimana air didinginkan. Untuk alasan ini, suhu wet bulb udara yang masuk ke menara pendingin menentukan tingkat suhu operasi minimum seluruh pabrik, proses, atau sistem.Berikut ini harus dipertimbangkan ketika melakukan seleksi awal menara pendingin berdasarkan suhu wet bulb:Secara teoritis, sebuah menara pendingin akan mendinginkan air menuju suhu wet bulb. Dalam prakteknya, bagaimanapun, air didinginkan sampai suhu lebih tinggi dari suhu wet bulb karena panas harus ditolak dari menara pendingin.Sebuah pra-pemilihan menara berdasarkan pada suhu desain wet bulb harus mempertimbangkan kondisi lokasi menara. Desain suhu wet bulb juga tidak boleh melebihi lebih dari 5 persen dalam sekali. Secara umum, suhu desain yang dipilih dekat dengan rata-rata suhu wet bulb maksimum di musim panas.Konfirmasi apakah suhu wet bulb ditentukan sebagai suhu lingkungan (suhu di daerah menara pendingin) atau inlet (suhu udara masuk menara, yang sering terkena resirkulasi pelepasan uap ke menara). Akibatnya, resirkulasi tidak dapat diketahui sebelumnya, suhu wet bulb lingkungan lebih dipentingkan.Konfirmasikan dengan pemasok jika menara pendingin mampu mengatasi efek dari peningkatan suhu wet bulb.Suhu air dingin harus cukup rendah untuk menukar panas atau mengembunkan uap pada tingkat suhu optimum. Kuantitas dan suhu penukaran panas dapat dipertimbangkan ketika memilih ukuran menara pendingin dan penukar panas yang tepat pada biaya terendah.*The range increases when the quantity of circulated water and heat load increase. This means that increasing the range as a result of added heat load requires a larger tower. There are two possible causes for the increased range:The inlet water temperature is increased (and the cold-water temperature at the exit remains the same). In this case it is economical to invest in removing the additional heat.The exit water temperature is decreased (and the hot water temperature at the inlet remains the same). In this case the tower size would have to be increased considerably because the approach is also reduced, and this is not always economical.

Jarak meningkat jika kualitas edaran air dan muatan panas meningkat. Ini berarti bahwa peningkatan jarak akibat beban panas yang ditambahkan memerlukan menara yang lebih besar. Ada dua kemungkinan penyebab kisaran meningkat:Suhu air masuk meningkat (dan suhu air dingin yang keluar tetap sama). Dalam hal ini akan ekonomis untuk berinvestasi dalam menghilangkan panas tambahan.Suhu air keluar menurun(dan suhu air panas di inlet tetap sama). Dalam hal ini ukuran menara harus ditingkatkan sebab pendekatan juga berkurang, dan hal ini tidak selalu ekonomis.*The design wet bulb temperature is determined by the geographical location. For a certain approach value (and at a constant range and flow range), the higher the wet bulb temperature, the smaller the tower required. For example, a 4540 m3/hr cooling tower selected for a 16.67oC range and a 4.45oC approach to 21.11oC wet bulb would be larger than the same tower to a 26.67oC wet bulb. The reason is that air at the higher wet bulb temperature is capable of picking up more heat. This is explained for the two different wet bulb temperatures:Each kg of air entering the tower at a wet bulb temperature of 21.1oC contains 18.86 kCal. If the air leaves the tower at 32.2oC wet bulb temperature, each kg of air contains 24.17 kCal. At an increase of 11.1oC, the air picks up 12.1 kCal per kg of air.Each kg of air entering the tower at a wet bulb temperature of 26.67oC contains 24.17 kCals. If the air leaves at 37.8oC wet bulb temperature, each kg of air contains 39.67 kCal. At an increase of 11.1oC, the air picks up 15.5 kCal per kg of air, which is much more than the first scenario.

Desain suhu wet bulb ditentukan oleh lokasi geografis.Untuk nilai pendekatan tertentu (dan pada jarak konstan dan jarak aliran), semakin tinggi suhu wet bulb, semakin kecil menara yang diperlukan.Sebagai contoh, sebuah menara pendingin 4540 m3 / jam yang dipilih untuk aliran 16.67oC dan pendekatan 4.45oC ke 21.11oC wet bulb akan lebih besar dari menara yang sama dengan wet bulb 26.67oC. Alasannya adalah udara di suhu wet bulb yang lebih tinggi mampu mengambil lebih banyak panas. Hal ini dijelaskan untuk dua suhu wet bulb yang berbeda: Setiap kg udara yang memasuki menara pada suhu wet bulb 21.1oC mengandung 18,86 kkal. Jika udara meninggalkan menara pada 32.2oC suhu wet bulb, setiap kg udara mengandung 24,17 kkal. Pada kenaikan 11.1oC, udara mengambil 12,1 kkal per kg udara.Setiap kg udara yang memasuki menara pada suhu wet bulb 26.67oC mengandung 24,17 kKal. Jika udara meninggalkan menara pada 37.8oC suhu wet bulb, setiap kg udara mengandung 39,67 kkal. Pada kenaikan 11.1oC, udara mengambil 15,5 kkal per kg udara, yang jauh lebih besar dari penjelasan pertama.*In a cooling tower, hot water is distributed above fill media and is cooled down through evaporation as it flows down the tower and gets in contact with air. The fill media impacts energy consumption in two ways:Electricity is used for pumping above the fill and for fans that create the air draft. An efficiently designed fill media with appropriate water distribution, drift eliminator, fan, gearbox and motor with therefore lead to lower electricity consumption. Heat exchange between air and water is influenced by surface area of heat exchange, duration of heat exchange (interaction) and turbulence in water effecting thoroughness of intermixing. The fill media determines all of these and therefore influences the heat exchange. The greater the heat exchange, the more effective the cooling tower becomes.

Dalam menara pendingin, air panas didistribusikan diatas media pengisi dan didinginkan melalui penguapan ketika menuruni menara dan bersentuhan dengan udara. Media pengisi mengakibatkan konsumsi energi dalam dua cara:Listrik digunakan untuk memompa ke atas bahan pengisi dan untuk kipas yang menciptakan draft udara. Media pengisi yang didesain secara efisien dengan distribusi air yang tepat, drift eliminator, kipas, gearbox, dan mesin yang menyebabkan konsumsi listrik yang lebih rendah.Pertukaran panas antara udara dan air dipengaruhi oleh luas permukaan pertukaran panas, durasi pertukaran panas (interaksi) dan turbulensi dalam mempengaruhi air dalam pencampuran yang teliti. Media pengisi menentukan semuanya dan oleh karena itu mempengaruhi pertukaran panas. Semakin besar pertukaran panas, semakin efektif menara pendinginnya.*There are three types of fills: Splash fill media: splashing water over the fill media into smaller water droplets. Film fill media: water forms a thin film on either side of fill sheets. Low-clog film fills: higher flute sizes were recently developed to handle high turbid waters (e.g. sea water). These influence the liquid to gas ratio, heat exchange, pumping costs, which all impact on energy use. The table compares these parameters between the three fill types.

Ada tiga jenis media pengisi :Splash fill media : cipratan air diatas media pengisi menjadi tetesan air kecil.Film fill media: air membentuk lapisan tipis pada kedua sisi lembaran pengisi.Low-clog film fills: ukuran flute yang lebih tinggi saat ini dikembangkan untuk menangani air yang keruh (misalnya air laut).Ini mempengaruhi rasio cairan ke gas, pertukaran panas, biaya pompa, yang semuanya berdampak pada penggunaan energi. Tabel tersebut membandingkan parameter antara ketiga jenis pengisi.*There are three areas for energy conservation with pumps and water distributionPumps: Areas for energy efficiency improvements are discussed in details in the Pumps and Pumping Systems chapter.Optimize cooling water treatment: Cooling water treatment (e.g. to control suspended solids, algae growth) is mandatory for any cooling tower independent of what fill media is used. With increasing costs of water, efforts to increase Cycles of Concentration (COC), by cooling water treatment would help to reduce make up water requirements significantly. In large industries and power plants improving the COC is often considered a key area for water conservation.Install drift eliminators: It is very difficult to ignore drift problems in cooling towers. Nowadays most of the end user specifications assume a 0.02% drift loss. But thanks to technological developments and the production of PVC, manufacturers have improved drift eliminator designs. As a result drift losses can now be as low as 0.003 0.001%.

Ada tiga area untuk konservasi energi dengan pompa dan distribusi air.Pumps: Area untuk perbaikan efisiensi energi dibahas secara rinci di Pumps and Pumping Systems chapter.Optimize cooling water treatment: Pengolahan air pendingin (misalnya untuk mengontrol padatan tersuspensi, pertumbuhan alga) diwajibkan bagi setiap menara pendingin independen yang menggunakan media pengisi. Dengan meningkatnya biaya air, upaya untuk meningkatkan Siklus Konsentrasi (COC), dengan pengolahan pendingin air akan membantu mengurangi kebutuhan air secara signifikan. Dalam industri besar dan pembangkit listrik meningkatkan COC sering dianggap sebagai wilayah kunci untuk konservasi air.Install drift eliminators: sangat sulit untuk mengabaikan masalah drift dalam menara pendingin. Saat ini sebagian besar spesifikasi pengguna akhir mengasumsikan kehilangan karena penyimpangan 0,02%. Namun berkat perkembangan teknologi dan produksi PVC, produsen telah meningkatkan desain eliminator drift. Sehingga kerugian bisa serendah 0,003-0,001%.*The purpose of a cooling tower fan is to move a specified quantity of air through the system. The fan has to overcome the system resistance, which is defined as the pressure loss, to move the air. The fan output or work done by the fan is the product of air flow and the pressure loss. The fan output and kW input determines the fan efficiency. The fan efficiency in turn is greatly dependent on the profile of the blade. Blades include:Metallic blades, which are manufactured by extrusion or casting processes and therefore it is difficult to produce ideal aerodynamic profilesFiber reinforced plastic (FRP) blades are normally hand molded which makes it easier to produce an optimum aerodynamic profile tailored to specific duty conditions. Because FRP fans are light, they need a low starting torque requiring a lower HP motor, the lives of the gear box, motor and bearing is increased, and maintenance is easier.A 85-92% efficiency can be achieved with blades with an aerodynamic profile, optimum twist, taper and a high coefficient of lift to coefficient of drop ratio. However, this efficiency is drastically affected by factors such as tip clearance, obstacles to airflow and inlet shape, etc. Cases reported where metallic or glass fiber reinforced plastic fan blades have been replaced by efficient hollow FRP blades. The resulting fan energy savings were in the order of 20-30% and with simple pay back period of 6 to 7 months (NPC).

Tujuan dari kipas menara pendingin adalah untuk memindahkan sejumlah udara tertentu melalui sistem. Kipas harus mengatasi perlawanan sistem, yang didefinisikan sebagai kehilangan tekanan, untuk memindahkan udara. Output kipas atau kerja yang dilakukan oleh kipas adalah produk dari aliran udara dan kehilangan tekanan. Output kipas dan input kWn menentukan efisiensi kipas.Efisiensi kipas sangat tergantung pada profil bilahnya. Bilah pisau termasuk :Pisau logam, yang diproduksi oleh proses ekstrusi atau casting dan oleh karena itu sulit untuk menghasilkan profil aerodinamis yang ideal.Pisau plastik (FRP) yang dibentuk secara normal dengan tangan yang membuatnya lebih mudah untuk menghasilkan profil aerodinamis yang optimal disesuaikan dengan kondisi tugas tertentu. Karena kipas FRP ringan, mereka membutuhkan torsi awal yang rendah dan mesin HP rendah, gear box, mesin dan hubungannya meningkat, dan pemeliharaannya lebih mudah.Efisiensi 85-92% dapat dicapai dengan pisau kipas dengan profil aerodinamis, sentuhan yang optimal, tepat dan koefisien tinggi lift untuk koefisien rasio penurunan. Namun, efisiensi ini secara drastis dipengaruhi oleh faktor-faktor seperti pemberesan tip, hambatan untuk aliran udara dan bentuk inlet, dll.Kasus yang dilaporkan dimana metallic or glass fiber reinforced plastic fan blades telah digantikan dengan bilah pisau FRP berongga yang efisien. Penghematan energi kipas yang dihasilkan berada di urutan 20-30% dan akan dengan mudah diganti selama periode 6 sampai 7 bulan (NPC).*Hello.

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