Heat, absorbed by the water in the closed system, is normally transferred by a water-to-water exchanger to the recirculating water of an open recirculating system, from which the heat is lost to atmosphere (Figure 32-1). Whatever the active agent is in your treatment (nitrite, molybdate, or polymer) the concentration must be regularly monitored. this website, certain cookies have already been set, which you may delete and Some success has also been recorded with nitrite-based treatment of closed brine systems at treatment levels of about 2000 ppm as. Still, every scenario is unique in its own way and you can contact us today to learn more about our, Closed-Loop System with Plate Heat Exchanger, Closed-Loop System with Shell & Tube Exchanger. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Learn more about Inductotherm Group and our 40 companies around the world. An appropriate inhibitor such as nitrite or molybdate should be added to sufficient levels to maintain corrosion protection. Where condensate is available, it is preferred for closed system cooling water makeup. A slightly alkaline pH increases the stability of either oxide layer. Systems containing steel and copper couples require treatment levels in the 5000-7000 ppm range. Figure 5 shows copper oxides that have deposited out in a feather-like structure on the copper surface. Efficiency also increases in the winter when closed loop systems can operate dry, preventing freezing during the colder months. Inductotherm Closed-Circuit Industrial Coolers, 2023 Inductotherm Corp. | ALL RIGHTS RESERVED, Horizontal Induction Tunnel Furnace Systems, Induction Systems for Vacuum and Controlled Atmospheres, High Resistance Load (HRL) Melting Systems, No Condensation Problems When Used with a Diversion Valve, Minimum Corrosion, Scaling and Electrolysis, Internal Water-to-Water Heat Exchanger for Ease of Installation, Completely Closed-Loop Pressurized Circuit, Fan Cycling Controls for Reduced Power Usage. However, fewer utilities have opted to go for the extra steps required to create and maintain an alkaline pH. O&M. Because glycol antifreezes are not compatible with chromate-based treatments, nonchromate inhibitors should be used. Some plants blanket the head tank with nitrogen, or even hydrogen, to preclude any air. This means that the decrease in temperature is rapid, reliable, and as effective as it gets. Controlling Copper Levels in Cooling Towers. Save valuable resources, time & money Water Chillers In-Stock For more information about our water treatment and system maintenance, contact us today. alternatives is their materials of construction, durability, and ease of maintenance. Currently, we have 25wt% glycol water in the systems. Low dissolved oxygen can be maintained by keeping the system leak free to limit the amount of makeup water. The major benefits of these are cost-effectiveness, as well as outright effectiveness through significantly colder cooling water delivered to process. Replace water-cooled equipment with air-cooled equipment or best available energy/water-efficient technology. A stator cooling water system contains the following components: A head tank containing the deionized water that provides suction to the pumps, Filters (cartridge filters, mesh strainers, or both), Monitoring for flow, temperature, conductivity, dissolved oxygen, and, in some cases, pH. They are hybrids that pass the working fluid through a tube bundle, upon which clean water is sprayed and a fan-induced draft applied. This can cause the copper oxide to be converted from one form (cupric) to the other (cuprous). Closed cooling systems that are shut down periodically are subjected to water temperatures that may vary from ambient to 180F (82C) or higher. Unimpeded flow through all stator bar openings is critical to operation of the generator and minimizing the transport of particles into places where they can cause blockage. *Trademark of Veolia; may be registered in one or more countries. This can lead to low inhibitor levels and biological fouling. Alkaline pH treatment can improve either the low or highdissolved oxygen regime. The stator cooling water system is a very special closed loop for a couple of reasons. Cooling capacity (refrigeration tons) 0.8 to 3.1; Single circuited systems; Medium Size Water Cooled Portable Chiller. There is only one metal of concern in this system: copper. An increase in water temperature causes an increase in corrosion. It also involves looking at a variety of related temperatures and pressures for trends that can predict an approaching problem. Focus on: Power, Process cooling, Data Center, Gas Turbine Air Cooling, Organic Rankine Cycle - ORC, Air Compressor, Biogas.. . However, this is not the only way closed systems can adapt to changes. 1/2 Ton to 20 Ton Water Chiller Systems in Stock. Visit us at www.atlascopco.com/industrial-cooling! Polymer Treatments. Personalize your experience by selecting the topics you are interested in below. Small temperature increases in stator cooling bars can restrict load on or even shut down the generator. Of those power plants that have water-cooled stators, there is almost an even split of high- and low-oxygen regimes, with the slight numerical advantage to those operating in the highdissolved oxygen regime. Closed circuit cooling towers, also known as evaporative fluid coolers, keep the system clean and contaminant-free in a closed loop. Chromates may be used with alcohol antifreeze, but the pH of the circulating water should be maintained above 7.0 to prevent chromate reduction. It uses less energy and has a lower carbon footprint than air conditioning. Regular treatment of the water and the system itself will ensure it continues to operate flawlessly for years. Generally, demineralized water is used for closed-loop cooling water makeup, but chemical treatments are required to prevent corrosion and, in some systems, freezing. There are three main types of closed-loop cooling systems: closed-loop dry systems, closed-loop evaporative systems, and liquid-to-liquid cooling systems. The simplest way to describe the way in which this system works would be to compare it to a massive, complex chimney. Plate heat exchangers are, in many ways, ideal for closed-loop cooling and utility duties. At Chardon Labs, we can help with these tasks and many others for your system. Thats why stator cooling water should be continuously monitored for conductivity and dissolved oxygen. Through these complex, industrial constructs, this high temperature is regulated quite efficiently and both the, The reason why this method is so popular is due to the fact that its a natural cooling system, which uses direct contact with fresh air to cool the hot water from the system. HydroThrift's industrial closed-loop chilled-water (CW) cooling systems are the solution for your most demanding equipment cooling requirements and severe environmental conditions. Pfannenberg, Inc., a leading global manufacturer of thermal management and signaling technologies, highlights its high-efficiency liquid cooling solutions for industrial electronics. However, in diesel and gas engines, the high temperature of the jacket water significantly increases its tendency to deposit scale. Little, if any, evaporation occurs. In some systems, nonoxidizing biocides such as glutaraldehyde or isothiazoline are added to the treatment to prevent bacterial growth. This is the only way in which the system works, seeing as how there has to be a difference in density between hot air at the top and the air outside of the cooling tower. With the small amount of makeup water required, adequate treatment can virtually eliminate corrosion and the accumulation of corrosion products. But before you request a quote, you should understand your system and why water treatment is vital to maintaining it. The toxicity of high-chromate concentrations may restrict their use, particularly when a system must be drained frequently. Curve B shows data for a vented system. 3D TRASAR technology for cooling water systems can help you reach your sustainability goals by reducing . Ironically, in closed-loop systems that are very tight, dissolved oxygen levels can drop, and thus minimize the effectiveness of a molybdate treatment (which requires dissolved oxygen to form a passive layer). Water systems help cool bearings, while other coolers chill lube, air compressors and oil. The shape of the system is such that it naturally draws a draft into the tower, eliminating the need for a mechanical fan system with a propeller and motor. Abundant growth of bacteria, algae and fungi on surfaces can lead to microbiological fouling in cooling water systems. Alfa Laval is a world-class supplier ofclosed-loop cooling solutions for justabout any industry where such solutionsplay a key role. Heat Rejection Systems. Mechanical Draft Cooling Systems Mechanical draft cooling is an industrial cooling water system, which involves the use of an evaporation process for cooling. 00. . Box 157 Rancocas, NJ 08073-0157. Only see the articles on the blog you are interested in reading. Various microbes will produce acidic by-products that will suppress pH and increase corrosion. Closed loop systems have more uses than for emergencies. Defense Daily subscriber and registered users, please log in here to access the content. and cookie policy to learn more about the cookies we use and how we use your Common types of equipment that may use OTC includes commercial and industrial air conditioners, wok stoves, walk-in cooler and freezes, and ice machines. Where circulating pumps are equipped with certain mechanical seals, such as graphite, chromate concentrations may not exceed 250 ppm. Over a long period, the addition of even small amounts of hard makeup water causes a gradual buildup of scale in cylinders and cylinder heads. The chemistry of copper in oxidizing and reducing conditions has been the subject of a great deal of research, and we have a better understanding now of the conditions that cause corrosion, which is a common problem. CEC coolers also eliminate the complications and expense of industrial effluent. Borates protect closed-loop systems in three ways: Corrosion inhibition, buffering, and cleaning. In addition to leaks, bacteria or mineral deposits can reduce the ability of the system to transfer heat by coating the surfaces of the parts. He helps consult a wide range of customers utilizing various methods of water treatment, from chemical to chemical-free approaches, large and small applications, and across a wide range of geographical influences. That price variability can make molybdate treatment competitive with nitriteor far more expensive. Atlas Copco Celebrates 150 Years of Innovation, Industrial Cooling Technologies in Focus: Closed Loop-Cooling Systems, Top 5 Compressed Air and Gas Articles of 2021. The driving force for the transfer of heat is the difference in temperature between the two media. David Daniels ([emailprotected]) is a frequent contributor to POWER and senior principal scientist at M&M Engineering Associates Inc. In a vented system, this tendency is reduced by the decreased solubility of oxygen at higher temperatures. When left unchecked, microbiological growth can quickly form a biofilmon wetted surfaces. pump station with overhead "water fall" tank for reduced footprint The CleanLOOP WVF Series Water fall Pump . Top 5 Best Closed Loop CPU Coolers. The byproducts of bacterial respiration are often acidic, and respiration also consumes oxygen, causing the base of the biofilm to be conducive to corrosion of the base metal. Quaternary Ammonium/Tin biocides have been shown to control most types of microorganisms found in closed loop systems. Minimize your system energy, maintenance, and installation costs with the FXV Closed Circuit Cooling Tower, the industry standard for closed-loop systems. You will be redirected once the validation is complete. Cooling tower systems have been used by industry for years to provide a means of removing waste heat generated by machinery or manufacturing processes. Aside from emergency use, closed circuit cooling systems also serve to cool down components at a power plant. When a chiller is substituted out for city water, the payback can be as short as a year. Nitrite- molybdate-azole blends inhibit corrosion in steel, copper, aluminum, and mixed-metallurgy systems. The formation of the cuprous oxide is limited by the amount of dissolved oxygen in the water. In the closed-loop chiller, the coolant is first chilled in a coolant tank, then circulated throughout the process/equipment; during this circulation, the coolant absorbs heat from the application and equipment. Make sure unit is level. Alfa Laval ALF filters remove unwanted material including sand and various biological matter from the cooling water before it enters the plate heat exchangers. Closed loop systems do not have an opening to the air, but this does not mean the system has complete protection from foreign matter in the water. The benefit of packaged towers is that theyre much simpler and quicker to install, can be modular for future expansion and dont carry the risk of field erection time and costs. Pfannenberg EB 2.0 Large Packaged Chillers and PWS Series Air to Water Heat Exchangers provide contaminant-free, cost-effective component cooling without adding heat to the local environment. The reason why this method is so popular is due to the fact that its a natural cooling system, which uses direct contact with fresh air to cool the hot water from the system. Grab sampling is not usually done due to the amount of water required to flush out sample lines before one can be sure of getting an accurate sample, which then needs to be replaced. There are often two deionizer vessels and two sets of filters to allow one to be valved out to replace the filter cartridge or for replacement of the mixed-bed resins. The general guidelines for nitrite-based treatments are for a minimum of 700 ppm of nitrite. Energy Costs = 100 kW 0.3 kW/kW 4,800 hours x $0.1 / kW-hour x 1.0 duty cycle = $14,400 per year. Visit AtlasCopco.com - Legal Notice & Cookies, Saving Money with Water-Cooled Chillers What to Know. The feed of nonoxidizing antimicrobial may be necessary to control nitrite reversion andbiological fouling. The use of high-quality water also minimizes the dangers of cracked cylinders, broken heads, fouled exchangers, and other mechanical failures. System pH is normally controlled between 7.0 and 9.0. step of the way. Several sectors take advantage of more efficient closed circuit cooling systems. This blog is written once per month by one of our technical sales managers. Hot water from the condenser or other piece of equipment is sprayed on horizontal slats or corrugated PVC fill-packs. An analysis should be performed to identify existing or future or problems within the system. In the condenser of the chiller, the heat is . Among the equipment that may be on closed cooling networks are steel mill furnace housings, refinery and chemical plant process heat exchangers, turbine lubricating oil coolers, pump bearings, air compressor interstages, building heating/cooling systems, and more (see Fig. Consequently, there is less maintenance and less pumping - both of which result in significantly lower operating costs. For this reason, they are sometimes referred to as a closed loop circulating pump. Closed loop systems maintain water volume and quality; typically experiencing losses of less than 10% of its total . Not changing the cartridge filters or replacing the demineralizer resins when the differential pressure calls for it will accelerate the plugging of the stator bars. Mechanical draft cooling is an industrial cooling water system, which involves the use of an evaporation process for cooling. These impurities are generally dissolved carbon dioxide and ionized (dissolved) copper corrosion products. This can be a problem. data. Because the carbon steel and copper corrosion treatment are typically blended into one product, low levels of treatment may affect more than just the carbon steel piping. If a freeze protection solution such asglycol is incorporated, freeze protection point and percentage glycol should be performed. In a closed system, it can be quite difficult to prevent corrosion of aluminum and its alloys; the pH of the water must be maintained below 9.0. sure you'll be pleased with our The oxygen-deficient area underneath the deposit becomes the anode, and the area around the deposit that is exposed to the bulk water becomes the cathode. By performing these tests on a routine basis many problems can be identified long before they progress to the point of failure. Compared to other technologies such as stand-alone cooling towers, closed-loop cooling with plate heat exchangers requires less make-up water and minimal water treatment. This occurs because the lower solubility of oxygen with increasing temperatures in a freely vented system decreases the corrosion rate faster than the rise in temperature increases it. Biocides make it possible to control such factors, with two classes of biocides available: It is crucial to control bacterial levels in closed water systems from the point of the first fill. We provide you with a clean system via our expert maintenance. Consequently, there is less maintenance and less pumping both of which significantly reduce operating costs. The conductivity is critical and generally is kept below 0.5S/cm. Find out how we can help improve the thermal performance of your closed systems, lower energy bills, reduce maintenance costs and down-time, and extend plant life-cycles. Stator cooling water is contained in a closed-loop system that cools the copper stator bars in water-cooled generators. Effective pretreatment defends against the majority of closed loop system concerns. Visit our updated, This website requires certain cookies to work and uses other cookies to help you have the best experience. A closed loop water chiller system can be installed in any building, regardless of its size or age. Closed-loop Evaporative Cooling Systems A closed-loop evaporative system is a hybrid system. For instance, backup power generators used for commercial structures like hospitals or industries typically have closed loop systems. Moreover, as weve mentioned, not all of these systems are made equal and some are standard for specific industries. Cupric oxide (CuO) can be formed when dissolved oxygen is high (>2 ppm). Another problem is encountered when chromate inhibitors are used in cooling systems serving compressors that handle sour gas. Lowered pH could indicate bacterial growth or a system leak, affecting both the water levels and chemistry. 100 kW of cooling requires 30 kW of electricity to operate the chiller. By visiting this website, certain cookies have already been set, which you may delete and block. Maximum inhibitor effectiveness can be achieved if the pH of these systems is kept between 7.5 and 9.5. Fluid coil cooling systems are usually smaller; however, they can be custom-made in order to serve as industrial cooling systems. Industries often need backup plans in the event of power losses. A major consideration when considering mechanical industrial cooling systems alternatives is their materials of construction, durability, and ease of maintenance. OTC systems can be big water wasters. The stator cooling water systems heat transfer surfaces are generally pure copper. Flushing and chemical pretreatment are necessary to keep bacteria, algae and fungi from proliferating on pipe surfaces. Copyright 2023. The pH of the water should also be tested regularly. This separates the working fluid, which means that there is no water loss in this system, as a result. The control of biological agents, like bacteria and algae, is vital to any effective cooling water treatment. These systemscan be configured into a variety of different systems depending on the cooling requirements of the system. Experience has taught us no two industrial cooling water systems are alike. Similarly, if there is a significant pressure drop across the deionizer or across the cartridge filters, or there are issues with the stator cooling water pumps, these can all slow the flow of the stator cooling water through the system, accelerating the release of the copper oxide and increasing the potential for plugging. In a closed system, water circulates in a closed cycle and is subjected to alternate cooling and heating without air contact. The two that are most likely to exist are the so-called bearing cooling water system (which takes care of more than just bearings) and the stator cooling system, for those plants that have a water-cooled stator. A closed circuit system keeps the water completely enclosed inside pipes, preserving water volume and quality. If you do not agree to the use of cookies, you should not navigate Protects the water source from contamination, Only 20% of the space compared to shell-and-tube. Your . From our low maintenance design Throughout the stator bars, the copper strands, including those that contain stator cooling water, change position in the bar itself. Closed loop liquid cooling systems offer an excellent means to efficiently meet the combined challenges of high heat loads, low thermal resistance, and low noise while easily managing die level . A Brief History of U.S. Coal Ash Since the Kingston Spill, Germanys Energiewende at a New Turning Point, Beyond the Firewall: Best Practices for Cybersecurity Risk Management, Xcel Energy: Committed to Renewables, but Going Its Own Way, New Metering Solution Controls Condensate in HRSG Systems, Entergy Grows Revenue, Increases Customer Satisfaction with Value-Added Services, Flexible & Reliable: Optimal performance amid variable power generation, AI in Renewables: The Secrets to Successfully Scaling a Diversified Fleet. Compact Pfannenberg EB 2.0 Large Packaged Chillers allow maximum cooling capacity in the smallest possible footprint. As the name suggests, closed-loop HVAC systems are sealed units containing a fixed volume of water. Chillers use the refrigeration cycle to remove heat from water. The ion exchange resins may also trap fine particles of copper oxides, though this is better done by the cartridge filters. www.watertechonline.com is using a security service for protection against online attacks. Compare our closed-loop solution to your current method for cooling your machinery: CEC coolers recirculate one tank of water, eliminating the need for a continuous and expensive on-line water supply. With 20 years of water treatment experience, including a wide range of troubleshooting and service in potable water and non-potable HVAC and industrial applications, he is an expert in water treatment chemistry for cooling towers, boilers, and closed-loop systems. Adding more nitrite only further accelerates the reproduction of the bacteria, making the problem worse. Visit our updated. Luckily, closed loop systems have a design that reduces the need for regular, rigorous cleaning and maintenance. All use some sort of water-to-water heat exchanger in con-junction with plant water (dirty water) supplied by a cooling tower, radiator/ fan, refrigeration type chillers, city water, well water, and geothermal field. If the plant experiences a loss of its primary cooling, the closed loop system allows for continued heat removal. Their main trait is that theyre pre-designed, built completely in a factory, and transported to the target location. Closed systems are also less susceptible to biological fouling from slime and algae deposits than open systems. Closed cooling water system To cool key processes in petrochemical plants, refineries, power plants and other heavy-duty industrial environments, many plant owners and operators rely on closed-loop cooling as the preferred cooling method. Before adding water treatment, on-site personnel should flush the closed loop to prevent bacteria from colonizing on the iron surfaces. help you have the best experience while on the site. In a closed system, water circulates in a closed cycle and is subjected to alternate cooling and heating without air contact. By visiting this website, certain cookies have already been set, which you may delete and block. To request a quote or for help sizing your water chiller, please contact us! Any particles that are trapped by the filters or by the deionization resins are particles that cannot reattach to the surface of the stator cooling channel. An existing system, dirty due to negligence, can often be restored to an acceptable working condition that is relatively problem free with minimal effort and expense. Increasing the pH of the stator cooling water also has been shown to be very effective at reducing copper corrosion and release rates. cooling systems usually consist of a closed-loop recirculating system to cool the power supply, heat station, coils, bus, and leads. However, these dry cooling systems result in warmer cold water so they are not as efficient as mechanical open industrial cooling systems. Cartridge filters that are normally supplied are 5m, and some plants have found that moving to a 1m cartridge filter is helpful. Some of the concerns with closed loop systems are corrosion, scale, particulate and microbiological growth. Their downside lies in the fact that theyre substantially smaller and, therefore, less potent than their field erection counterparts. An industrial tower is often used to cool the furnaces because it provides the greatest cooling power in the least amount of space, as well as expelling the most heat. Unfortunately, for those who operate industrial facilities, hot-water heating, process loops or closed-loop cooling-water recirculation systems are not among them. Product performance data developed in laboratory studies simulating a mixed-metallurgy closed cooling system identified steel and Admiralty corrosion rates for three closed system inhibitors at increasing treatment levels. High dissolved oxygen requires maintaining greater than 2 ppm of dissolved oxygen in the stator cooling water at all times. The American Society of Refrigeration Engineers has established chromate limits in brine treatments. The benefits of closed-loop chillers are multifold: There are three main types of closed-loop cooling systems: closed-loop dry systems, closed-loop evaporative systems, and liquid-to-liquid cooling systems. Generally, the chromate or molybdate types have proven to be superior treatments. Polymer treatments have been used for many years to prevent scale and corrosion product accumulations in open cooling towers. Target dissolved solids within the system to create less aggressive water. Cooling or heating systems that use water can dissipate heat acquired by the liquid with one of two methods closed loop or open loop. Molybdate works with the dissolved oxygen in the water to form a protective ferricmolybdate complex on the steel. The increased efficiency of a closed circuit system from proper water treatment ensures the generator has adequate cooling water and is always ready. Closed recirculating systems have many advantages. This further encourages some types of bacteria, as they use the oxidized metal in their metabolism. Another potential division of cooling systems can be based on the heat transfer technique that these cooling systems are using. Closed-loop cooling systems provide clean, nonfouling, nonscaling, noncorrosive coolant for many types of industrial equipment and processes. How to Inspect a Boiler and Find Serious Problems? Monitoring the health of stator water systems includes not only the chemical parameters like dissolved oxygen and conductivity. Closed-Loop Dry (Air-Cooled) Systems. All Rights Reserved BNP Media. These conditions can quickly deteriorate your system without you knowing until efficiency drops to detectable levels.