Water is a vital natural resource. It is important in all aspects of industrial buildings, but more so in the cooling systems. Cooling water systems are often used in commercial and industrial buildings. They are used in these industries to remove waste heat from the cooling process of HVAC systems. Monitoring the cooling water flow is essential in any structure that needs cooling. Any change in the cooling water flow will affect the overall performance of HVAC systems.
Cooling water often comes from natural sources, such as rivers, lakes, and streams. It is a free commodity that must be efficiently managed for various reasons. Present-day research focuses on the optimization of cooling water systems. Experts are exploring the possibility of recycling and reusing water in cooling systems. As well as reducing waste products and minimizing energy consumption.
According to Ball, “Measurements of cooling water are generally considered non-critical. But they can have a significant impact on the efficiency of a heat exchanger. It can lead to poor process temperature control. That results in quality or yield issues.” Accurately measuring water usage and flow rates are crucial processes of temperature control. Understanding the process is essential in knowing the importance of monitoring and measuring. Read along to know where cooling water provides an essential service to a process.
General Process And Types of Cooling Water Systems
Cooling systems remove heat from processes or equipment. The heat generated in the process is transferred from one medium to another. Cooling water is the medium used to transfer heat in the system. Effective removal of heat is a key function in the operation and design of a cooling system. Heat transfer from process fluids or equipment causes an increase in temperature. As well as change in the state of the cooling water. Various properties of the cooling water are affected by temperature. Corrosion, scaling, and even microbial growth are also affected by the water temperature.
There are two ways to control the water heated in the heat exchange process. First is the once-through cooling system. Here, water is released at an increased temperature into a receiving end. Second, the recirculating cooling system, wherein water is cooled and reused. The recirculating cooling system is further divided into two types. Open and closed recirculating systems.
In the open recirculating system, a small amount of water is evaporated to reach cooling. The evaporation leads to the loss of pure water and the concentration of dissolved solids. The used water must be discharged to control the concentration. Freshwater must be used to reoperate the system. While in a closed recirculating system, water is reused. It is a cooling system within a cooling system. The used water carrying the heat transferred from the process is cooled down. Later, it is reused by an exchange with another fluid. This type of recirculating system only uses a small amount of water.
Heat Exchange Economics in Cooling Water Systems
According to Ball, “Heat exchangers are used in hydrocarbon and nuclear power plants. They are also used in gas turbines, heating, and air conditioning. As well as refrigeration and the chemical industry. They are used to control process temperatures by using cooling fluid. It transfers thermal energy to a second fluid. Thereby heating the first fluid and cooling the second fluid. The flow rates at which the two fluids move through the heat exchanger determine the amount of heat transferred. It enables increased control over process temperatures.”
Power plants often have a heat exchanger system to ensure safe operation. As well as prevent dangerous temperature limits. All cooling systems must have a source of water for their cooling fluid. Heat is moved through the heating surface. That is, a wall of the inner tube transfers heat to a cold fluid. The heat exchanger system can also work in a counterflow movement. Two fluids are parallel but moving in opposite directions. While a concentric tube heat exchanger is built in various ways. It can be built as a coil or straight sections stationed next to each other and connected through a series.
As stated by Ball, “The most used type of heat exchanger is the shell-and-tube design. It uses a bundle of tubes through which the hot fluid flows. The tubes are enclosed in a shell design to let the cool fluid flow through the spaces between the tubes. In nuclear reactors, fuel rods will replace the tube bundle. The cooling fluid flowing around the rods removes the heat generated by the fission process.” In power plants, the hot fluid is cooled down first. Instead of discharging out into the environment, they are cooled down before proceeding to a scrubber process.
Process Temperature Control in Cooling Water Systems
Cooling systems function through the heat process. Hence, temperature control is of utmost importance to ensure safe operations. When water moves quickly, it can lead to damage to the heat exchanger system. When water is slow-moving, it can lead to stagnation. Likewise, if the water has too many impurities, water heating can lead to the deposition of minerals. It can cause corrosion or flow changes in the heat exchanger system. Calculating the correct water flow in and out of a heat exchanger system helps maintain its smooth function.
According to Julabo, “Water quality management for cooling systems requires high priority. Depending on the fluid circuit, additives are added to the recirculated water to reduce fouling. As well as help ensure trouble-free operation. Additives guard against piping corrosion, scaling, and biologic growth. Consider the use of inline filters. Particularly when using plate heat exchangers in the process. Fouling from particulates can quickly degrade efficiency. It can also lead to maintenance downtime and repairs.”
Water quality tests must be facilitated, especially in large systems with cooling towers. Cooling water must be thoroughly monitored to avoid the growth of microorganisms. Proper sanitation also ensures the safety of the system. Water monitoring helps ensure the most efficient performance of the cooling system.
Julabo wrote a few reminders in monitoring the temperature and flow of cooling water systems.
- Keep a daily log of operating temperatures and system pressure. As well as fluid levels, filter efficiency and flow rates. It helps in maintaining the most efficient operation for the cooling system.
- Note that any degradation in heat transfer efficiency will affect the process.
- Clean water circuit on an annual or demand basis to eliminate any fouling or corrosion. It helps maintain efficient operation.
- Periodic cooling-fluid testing should be conducted weekly or monthly. The precise schedule will depend on the process, fluid, and type of chiller.
Magnetic Flow Meters for Cooling Water Systems
According to Omega, “A magnetic flow meter is a volumetric flow meter that does not have any moving parts. It is ideal for wastewater applications. As well as any dirty liquid which is conductive or water-based. It is also ideal for applications where low-pressure drop and low maintenance are required. Magnetic flow meters will generally not work with hydrocarbons. Also in distilled water and many non-aqueous solutions.”
Magnetic flowmeters operate through magnetic fields to channel liquid flow. A voltage signal is generated as the conductive liquid runs through the flowmeter’s magnetic field. Faster flow means a higher voltage is produced. While electrode sensors in the flow tube walls collect voltage signals. Then, the signal is sent to an electronic transmitter. It processes the signal that determines the liquid flow.
Magnetic flowmeters provide essential data in cooling water systems. It measures the water flowing in and out of a cooling system. According to Ball, “An operator can view the cooling water flow rates. Operators can adjust control valves as needed. It helps to achieve and maintain the desired thermal transfer from the process fluid. It enables accurate temperature control. Efficiently keeping track of water flow reduces the expense for water. As well as other utility costs related to the process that are impacted by temperature.”
It is important to note that a magnetic flow meter is a low maintenance. It has no moving parts prone to wearing out. Right lining materials also decrease the chance of deposits sticking in the meter. The advanced diagnostic feature of this equipment can verify meter performance. Thus, it aids in complying with environmental regulations. As well as simplifying reporting requirements. Moreover, its wireless feature provides an enhanced method for collecting data. The wireless transmission of flow and diagnostic information. A magnetic flow meter is the most efficient way to monitor cooling water flow in industrial cooling systems.
Cooling Water Monitoring with AKCP
In chilled water cooling systems having sufficient water in the cooling tower is essential. With tank depth level sensors, you can easily monitor and be alerted, if the water level drops below the required levels.
Wireless Tank Level Sensor
Monitor the water level in the cooling tower and ensure you never run low and are ready for the most critical moments. Wireless Tank Level sensor can monitor depths up to 20 meters. Often tanks are located in outdoor or difficult to cable areas. The WT-TDPS is battery powered or can be powered from a 5V DC or 12VDC source. Track fuel usage, graph the tank level, receive alerts when tank levels are critical. No more constraints on maximum cable lengths from the base unit. Easy installation and pairing with AKCP Wireless Tunnel™ Gateways.
- 4xAA Battery powered, with 10-year life*
- Tank mounting kit with cable gland
- IP66 rated enclosure
- Monitor all kinds of liquids and fuels.
Pipe Differential Pressure Sensor
Digital pressure gauge for monitoring all kinds of liquids and gasses. Battery Powered, Wireless Tunnel™ Technology. Remote monitoring via the internet, alerts, and alarms when pressures are out of pre-defined parameters. Upgrade existing analog gauges. Retain your existing gauges with our installation kit. Easy setup and pairing with AKCP Wireless Tunnel™ Gateway.
Differential pressure sensors are useful for checking pressure drop across filters in your system. When pressure drop is significant, it can indicate dirty filters that require maintenance cleaning, or replacement. Receive alerts via e-mail, SMS, and other notification methods from AKCPro Server.
- 4x AA Batteries, with 10-year battery life*
- 5VDC or 12VDC powered
- IP66 Waterproof enclosure
- Multiple mounting options
Cooling water systems are crucial in industrial operations. These systems employ heat in their functions. Hence, they are prone to different failures such as corrosion, scaling, and bacterial growth. It is important to understand how cooling water systems work. It will help you optimize your cooling systems and prevent future problems.