Additional cooling of air coolers: overview 

Why standard air cooling is not enough for industrial systems and how additional cooling of air coolers works: an overview

In our engineering practice, we often encounter situations where standard heat exchanger fans cannot cope with peak loads, which leads to emergency shutdowns of equipment.Additional cooling of air coolers: overvieweffective solutions for modernization is not just a theoretical analysis, but a guide to action to prevent downtime in production. If the discharge air temperature exceeds the design 45°C, the standard design becomes ineffective and additional circuits or technologies such as adiabatic precooling or atomization are required. In this article, we'll dive into the technical aspects, economics, and real-life cases so you can make an informed decision about upgrading your air-cooling fleet.

The key problem that the additional system solves is the dependence of heat transfer efficiency on the ambient temperature. When the thermometer reads +35°C or higher, the temperature delta between the process fluid and the atmosphere is reduced and the heat exchanger no longer operates at design level. We have seen this reduce column throughput by 15-20% in refineries. The introduction of additional cooling systems allows you to return process parameters to nominal without replacing the main equipment, which is critical for extending the life cycle of assets.

Technical solutions for intensifying heat transfer: from adiabatics to hybrid systems

The choice of aftercooling method depends on climatic conditions, water availability and process requirements. We categorize key technologies by operating principle and effectiveness so you can compare their applicability to your facility.

Adiabatic Pre-Cooling Systems

This method is based on spraying fine water (mist) in front of the heat exchanger inlet grille. Evaporation of droplets reduces the temperature of incoming air by 10-15°C, which significantly increases air density and heat transfer coefficient. In our practice, we recommend using systems with osmotic water treatment and high-pressure nozzles (minimum 70 bar) to avoid the formation of droplets that can cause corrosion of aluminum lamellas. One of our clients in the Astrakhan region experienced rapid failure of nozzles due to the use of untreated process water, which led to clogging of channels and an increase in pressure drop. Important: installation of such systems requires accurate calculation of aerodynamic resistance so as not to overload the standard fans. If you are considering this option, request a dew point calculation for your region to avoid condensation on the equipment.

Evaporative cooling systems for filler (Fill Cooling / Wet-Dry Hybrid)

Unlike fogging, here water is supplied directly to the finned surface of the pipes or to a special filler in the lower part of the apparatus. This puts water in direct contact with the hot surface, using the latent heat of vaporization to dramatically increase heat removal. The efficiency of this method is higher than that of adiabatic pre-cooling, but it requires a more complex water treatment and scale protection system. We use this method for devices operating in modes where the process temperature is critical and does not allow fluctuations. For example, when cooling compressed gas, where a deviation of 2°C can violate technological regulations. Please note: this method increases water consumption, so its economic feasibility must be calculated taking into account local tariffs for water use and wastewater disposal.

Hybrid cooling towers and dry coolers with additional circuit

For facilities with strict requirements for the absence of visible steam (white plume) or with water shortages, we offer hybrid solutions. They combine a dry air circuit and a wet circuit, which can operate either in parallel or in series. In summer, the wet mode is turned on for peak cooling, in winter - only dry mode, which prevents freezing and fog. In our project for a chemical plant in Tatarstan, the use of a hybrid design allowed us to reduce water consumption by 60% compared to a traditional cooling tower, while maintaining the ability to shed the heat load on the hottest days. When selecting such equipment, it is critical to check for EAC certification for the pressure vessels if the hybrid module is integrated into the overall circuit. Contact our engineers to select a configuration for your process.

Mechanical intensification: increased air flow and recovery

Sometimes the problem lies not in the air temperature, but in its flow. Replacing fan motors with more powerful ones or installing variable frequency drives (VFDs) can solve the problem without changing the heat exchange surface. However, this path has limitations: the design of the device must withstand increased vibration loads and aerodynamic drag. We conducted tests where increasing the fan speed by 20% gave an increase in heat transfer of only 8% due to turbulence and flow stall. Therefore, before such an upgrade, CFD modeling of air flows is mandatory. If you are planning on upgrading your motors, make sure the control system has overcurrent protection and soft start capabilities to avoid mechanical damage to the blades.

Selection criteria and comparative analysis of additional cooling methods

To make an informed decision, you need to compare technologies based on key parameters. We have prepared a summary table based on our project data and industry standards. Please note that the figures are indicative and may vary depending on the specific device configuration.

Analysis of the table shows that there is no universal solution. For the dry climate of Kazakhstan or Central Asia, adiabatic systems are often the most cost-effective. At the same time, for facilities in the European part of Russia with high humidity and temperature changes, hybrid systems may be more reliable in the long term. We recommend conducting a feasibility study (TES) for each specific case, taking into account not only the cost of the equipment, but also the costs of water, electricity and maintenance over a period of 5-10 years. If you need help in carrying out such an analysis, our specialists are ready to provide a calculation based on your initial data.

Economic justification and calculation of the payback of modernization

Investment in additional cooling must be justified in terms of return on investment (ROI). We use the following model to calculate efficiency: savings from avoided downtime + increase in core process productivity - (CAPEX + OPEX per period). For example, at one of the polyethylene production plants, the installation of an adiabatic cooling system costing 12 million rubles made it possible to avoid a 5% decrease in line productivity in the summer months. This provided additional income of about 3.5 million rubles per month. Thus, the payback of the project was less than 4 months, not counting the indirect benefits from increased equipment reliability. It is also important to consider energy efficiency: modern systems with VFDs and smart controls can reduce their own energy consumption by 20-30% compared to constant operation. When calculating OPEX, be sure to include maintenance costs: replacing nozzles, cleaning filters, chemical water treatment. These costs can add up to 15% of the initial system cost per year. To get an accurate calculation for your business, use our ROI calculator or contact our engineers.

Practical aspects of installation and integration into existing systems

The success of a modernization project depends 80% on the quality of installation and commissioning. We have identified the key stages that need to be controlled:

1. Audit of the existing system and data collection.Before starting work, it is necessary to conduct a full inspection of the device: check the condition of the lamellas, collectors, fans, measure the actual temperature pressures and pressure drops. Often we find that the problem is not a lack of cooling, but dirty heat transfer surfaces or an incorrect control system setting. Skipping this step may result in installing additional cooling on a faulty device, which will not give the expected effect and lead to wasted costs.
2. Design and selection of components.Based on the audit data, engineers develop a piping scheme, select pumps, nozzles, sensors and a control system. It is critical to ensure that the water or mist is distributed evenly across the entire air intake front. We use CFD modeling to optimize nozzle placement to avoid dry spots and waste of water. At this stage, the location for installing additional equipment is also determined: on the frame of the existing apparatus or on a separate foundation.
3. Infrastructure preparation and installation.This stage includes the laying of pipelines, power supply, and installation of instrumentation and automation. Particular attention is paid to water quality: if process water is used, it is mandatory to install fine filters (at least 50 microns) to protect the nozzles. In our practice, there was a case when, due to the lack of a filter, the nozzles became clogged with scale after 2 weeks of operation, which led to uneven cooling and local overheating of the device. All work must be carried out in compliance with industrial safety requirements, especially when working at height and near operating equipment.
4. Commissioning and configuration of control algorithms.After installation, the system is tested in various modes. The on/off settings for additional cooling are adjusted depending on the process temperature and the environment. Modern systems use PID controllers to smoothly control water flow, which minimizes water consumption. It is important to train personnel in the operation and maintenance of the new system, provide regulations and instructions. We always provide on-site training to avoid future mistakes.
5. Monitoring and optimization after commissioning.The first 3-6 months of operation are a key period for data collection and fine-tuning. We recommend installing remote monitoring of parameters (temperature, pressure, water flow) in order to quickly respond to deviations. Based on this data, control algorithms can be optimized, for example, shifting the activation point for additional cooling for even greater water savings. Regular scheduled maintenance is the key to system longevity.

Remember that even the most perfect system requires attention. Regularly cleaning injectors, checking filters and calibrating sensors is not an additional expense, but an investment in reliability. If you are not confident in your ability to carry out such an upgrade, entrust the work to professionals with experience in the field of industrial heat transfer.

Standards, Certifications and Safety Requirements

Any intervention in the design of industrial devices must comply with strict regulations. In Russia and the EAEU countries, the key document is the Technical Regulations of the Customs Union “On the safety of machinery and equipment” (TR CU 010/2011). Retrofitted air coolers must have an EAC certificate of conformity. In addition, if the system uses pressurized water, it may fall under the requirements of TR CU 032/2013 “On the safety of equipment operating under excess pressure.” For electrical equipment, a certificate according to TR CU 004/2011 and TR CU 020/2011 is required. We also recommend following industry standards, such as GOST 31242-2004 (Air cooling units. General technical conditions) and GOST R 53682-2009 (Refrigeration units. Safety requirements). When choosing components (pumps, injectors, sensors), give preference to manufacturers whose products have the necessary certificates. This is not only a matter of legality, but also a guarantee of quality and safety. In our company, all proposed solutions undergo internal examination for compliance with current standards, which minimizes risks for the customer. Before starting a project, be sure to consult with the technical supervision department of your enterprise and, if necessary, with Rostechnadzor authorities.

Real cases: how additional cooling solves industrial problems

Theory is important, but practice is the decisive argument. We share two examples from our work that illustrate different approaches.

Case 1: Oil and gas compressor shop in Western Siberia.Problem: in summer, when the air temperature was above +30°C, natural gas compressors could not provide the design outlet pressure, which led to a decrease in gas supply to the pipeline. The standard air coolers couldn't cope. Solution: A modular adiabatic pre-cooling system with high pressure nozzles and a reverse osmosis water treatment system was installed. Result: the air temperature at the inlet to the heat exchanger decreased by 12-14°C, which allowed the compressors to reach nominal mode. The workshop's productivity increased by 8%, which is equivalent to an additional supply of 1.2 million m³ of gas per day. The payback period for the project is 5 months. An important lesson: in severe winter conditions, the system must be properly sealed and drained to avoid freezing. We have provided automatic draining and purging when the temperature drops below +5°C.

Case 2: Chemical plant in the Central region of Russia.Problem: The polymerization process required precise temperature control of the reactor. Existing cooling towers did not provide stability on hot days, which led to product failure. Solution: implementation of a hybrid cooling system with the ability to operate in dry and wet modes. The system automatically switched between modes depending on temperature and humidity. Result: the coolant temperature has stabilized within ±0.5°C all year round. Scrap rates were reduced by 90% and water consumption by 40% compared to a traditional cooling tower design. Capital costs were higher, but savings on raw materials and water provided a payback period of 2.5 years. Conclusion: for processes with high precision requirements, hybrid solutions, despite their complexity, are often optimal.

Эти примеры показывают, что правильное подобранное дополнительное охлаждение — это не просто затраты, а инструмент повышения эффективности и конкурентоспособности предприятия. Если вы видите схожие проблемы на своем производстве, не откладывайте анализ возможностей модернизации.

Frequently Asked Questions

Можно ли установить систему дополнительного охлаждения самостоятельно, без привлечения специалистов?

Теоретически, простые адиабатические системы “коробочного” типа можно смонтировать силами собственной службы КИПиА и механиков. Однако мы настоятельно не рекомендуем этого делать по нескольким причинам. Во-первых, критически важен точный расчет точки впрыска и дисперсности капель, чтобы избежать намокания электрооборудования и коррозии. Ошибка в расчетах может привести к короткому замыканию или выходу аппарата из строя. Во-вторых, интеграция с системой управления требует знаний в области автоматики и программирования ПЛК. Неправильная настройка может вызвать циклическое включение/выключение, что быстро износит оборудование. В-третьих, для легализации модернизации часто требуется разработка проекта и получение разрешений, что под силу только специализированным организациям. Наша рекомендация: привлеките инженеров с опытом в промышленном охлаждении для аудита и проектирования, а монтажные работы можно выполнить своими силами под их техническим надзором.

Как дополнительный контур охлаждения влияет на энергопотребление всего аппарата?

Влияние неоднозначно и зависит от типа системы. Адиабатические системы с форсунками высокого давления потребляют электроэнергию в основном для работы насосов (обычно 2-5 кВт на систему), что незначительно по сравнению с мощностью вентиляторов (десятки-сотни кВт). Moreover, by cooling the air it the density increases, which can slightly reduce the load on the fans while maintaining the same mass flow. Системы с охлаждением поверхности могут требовать больше энергии для циркуляции воды, но они позволяют снизить температуру процесса, что иногда уменьшает нагрузку на основное технологическое оборудование (например, компрессоры). Гибридные системы с ЧРП для вентиляторов могут дать значительную экономию электроэнергии в переходные сезоны, работая на пониженных оборотах. В целом, правильно спроектированная система дополнительного охлаждения должна снижать удельные энергозатраты на единицу отведенного тепла. Для точной оценки мы проводим энергоаудит до и после внедрения.

Что делать, если в регионе жесткие ограничения на водопользование?

Это распространенная ситуация, и она не является препятствием для модернизации. Во-первых, рассмотрите адиабатические системы, которые потребляют минимальное количество воды (только на испарение, без продувки). Во-вторых, для систем с прямым контактом обязательна установка замкнутого цикла водоподготовки с рециркуляцией и эффективной системой очистки (фильтры, умягчение, ингибиторы коррозии). Это сократит потребление свежей воды на 80-90%. В-третьих, изучите возможность использования альтернативных источников воды, таких как очищенные сточные воды предприятия (если их качество соответствует требованиям). В-четвертых, гибридные системы, работающие в основном в сухом режиме, могут быть оптимальным решением, так как вода используется только в пиковые периоды. Наконец, всегда проводите расчет экономического эффекта с учетом стоимости воды и штрафов за сверхлимитное потребление. Часто инвестиции в более дорогую, но водосберегающую технологию окупаются за счет снижения эксплуатационных расходов. Проконсультируйтесь с экологами вашего предприятия и местными регулирующими органами для выбора допустимого решения.

Заключение и следующие шаги для модернизации вашего оборудования

Дополнительное охлаждение аппаратов воздушного охлаждения — это проверенный способ повысить надежность, производительность и энергоэффективность промышленных систем в условиях растущих климатических и технологических нагрузок. Как мы показали в этом обзоре, выбор между адиабатическими, испарительными, гибридными или механическими решениями зависит от множества факторов: климата, доступности воды, требований процесса и бюджета. Ключ к успеху — в тщательном анализе исходных данных, профессиональном проектировании и качественном монтаже. Не откладывайте решение проблем с перегревом: каждый день работы в неоптимальном режиме — это потеря денег и ресурсов. Начните с аудита вашего существующего оборудования: измерьте реальные параметры, оцените потенциал модернизации.

Для реализации сложных проектов модернизации, где требуется не только установка дополнительных систем, но и замена или усиление основных теплообменных элементов, критически важен выбор надежного партнера.Wuxi Kaisheng LLCспециализируется на разработке и производстве высокоэффективного теплообменного оборудования для нефтегазовой, нефтехимической и энергетической отраслей. Наш опыт позволяет предлагать комплексные решения: от титановых кожухотрубных теплообменников и ASME высоконапорных аппаратов до специализированных воздушных охладителей и котлов-утилизаторов. Мы производим трубные пучки из коррозионностойких материалов, таких как нержавеющая сталь 316, морская латунь C46400, медно-никелевые сплавы и никелевые сплавы N06625, что гарантирует долговечность оборудования даже в агрессивных средах. Вся наша продукция сертифицирована по международным стандартам PED и ASME, отличаясь высокой теплоэффективностью и устойчивостью к экстремальным давлениям и температурам.

Компания «Уси Кайшэн» готова предоставить индивидуальные решения для модернизации вашего парка оборудования, обеспечивая стабильную работу технологических процессов по всему миру. Мы работаем в соответствии со стандартами ISO 9001 и имеем успешный опыт реализации проектов в России и СНГ.Contact us today, чтобы обсудить ваши задачи, получить консультацию по выбору материалов и предварительный расчет. Для получения дополнительной информации о наших решениях в области промышленного теплообмена посетите разделПромышленные системы охлажденияon our website.