The global demand for industrial process cooling remains at a steady high. Reliability and minimal downtime are key to consistent and profitable industrial and commercial processes.
Goto Huateng to know more.
This article will consider the best methods to attain the optimal temperatures required to operate production processes in the metal finishing, medical, brewing, and agricultural industries.
So, how does a chiller work? The process works in a loop, but we will start where the cooling medium interfaces with your process equipment.
The system's coolant absorbs thermal energy from your process, typically causing a phase change into a gas. The gaseous refrigerant is then circulated to a condenser which expels the heat through evaporative condensation or a cooling tower. This heat exchange condenses the cooling medium back into a cooler liquid that is sent back to process heating source to begin the cycle again.
The type of coolant utilized in a chiller is based on process needs and cost considerations. The most popular coolants used are either water or a mixture of water and another substance with suitable heat conduction properties ' like glycol compounds.
The use of water as chiller fluid is an economical one as in most cases the water can be easily sourced with minimal costs. Alternatively, purified (deionized water, reverse osmosis) water can be used in a water-based chiller to achieve a higher cooling efficiency.
Glycol based coolants are either composed of ethylene glycol or propylene glycol. While these two variants have similar physical properties, they should never be mixed. The major advantages which glycol coolants confer are an improved resistance to corrosion as well as antifreeze properties.
Using a glycol-water mix as a chiller coolant has various benefits over the use of plain water as a chiller fluid. These advantages are due to its unique physical properties which include a lower freezing point than water.
For water free of impurities, the freezing point is 32°F which is much higher compared to pure ethylene glycol which changes to its solid-state at 8.9°F. When a glycol-water mixture is altered, the freezing point of the coolant also changes. To cite an example, 10% ethylene glycol will freeze at 25.9°F while a 60% glycol solution will freeze at -63°F.
From the above analysis, it's clear that glycol has refrigerant properties that are more suited for use in chillers expected to function in low-temperature environments. In these thermal conditions, a water coolant will freeze and obstruct chiller circulation while diminishing overall efficiency.
By contrast, utilizing a glycol-based chiller will take advantage of its antifreeze properties ensuring the coolant remains in a desirable fluid state.
Both glycol and water chillers can be used to satisfactorily dissipate the heat being generated by your production process. The fundamental difference between both chiller types lies in variations in their freezing points as well as their heat conduction capacities.
Pure glycol or a mix of glycol and water has a much lower freezing point than that of pure water. By implication, glycol-based chillers are better suited to low-temp environments. Conversely, water has a better ability to retain and conduct heat from an associated process than a glycol mixture can. As a result, the efficiency of heat transfer for a water chiller will be higher than that of a glycol chiller.
Overall, operators need to consider the ambient temperatures for the siting environment before choosing a chiller type.
A glycol chiller plant is composed of a refrigeration component and tubing containing a glycol-water mixture as coolant. Chilled fluid from the refrigeration unit is channeled through the piping associated with a thermal exchanger surrounding a heated process. After absorbing heat from the associated process, the warmed coolant is returned to the refrigeration unit for cooling after which the process is repeated.
For many chiller types, ethylene glycol is mixed with water at a ratio of 60/40. This higher percentage of glycol boosts the mixture's antifreeze properties significantly. This is useful in cases where rapid cooling is required. In these situations, a process can be cooled to very low temperatures without freezing the coolant within its piping.
A conventional water chiller works on the principles of heat transmission between various mediums both fluid and solid. These cooling systems work either by heat absorption or vapor compression. The basic components of a water chiller system include a refrigeration unit and a piping system that circulated chilled coolant.
For the last thirty years, Cold Shot Chillers has been manufacturing premium industrial chillers. With an impressive line of water- and air-cooled chiller units, your industrial cooling needs are sure to be met.
Glycol is a substance commonly used in heating and cooling systems for its freeze protection capabilities.
In this blog, we will discuss what glycol is, why it's used in heating and cooling systems, and how it affects system calculations.
Glycol is a type of organic compound characterized by the presence of multiple hydroxyl (-OH) groups.
There are several types of glycols, but the most commonly used in heating and cooling systems are ethylene glycol and propylene glycol.
Glycol is typically mixed with water to create a solution that provides freeze protection, corrosion resistance, and efficient heat transfer.
The primary reasons for using glycol in heating and cooling systems include:
The presence of glycol in a system increases the fluid's viscosity, which in turn affects the friction loss calculations.
You can learn more about Friction Loss Calculations here.
Contact us to discuss your requirements of Glycol Unit Cooler. Our experienced sales team can help you identify the options that best suit your needs.
Higher viscosity fluids experience greater resistance to flow, resulting in increased friction losses.
When designing a glycol-based system, it is essential to account for these increased losses to ensure proper pump and pipe sizing.
You can see the viscosity for various water / glycol mixes in the table below:
Glycol solutions generally have lower thermal conductivity compared to pure water.
This reduction in thermal conductivity means that glycol-based systems generally require higher flow rates to achieve the desired heat transfer performance.
Adding glycol to a system has several implications for system sizing:
Using glycol in heating and cooling systems offers numerous benefits, such as freeze protection, corrosion resistance, and efficient heat transfer.
However, it is essential to understand how glycol affects system calculations, such as friction losses and thermal conductivity, to ensure proper system sizing and optimal performance.
By considering these factors, you can effectively implement glycol into your heating and cooling systems for reliable and efficient operation.
The video below gives an overview of the difference that the glycol mixture has on a system's sizing calculations:
Mixing different types of glycol is generally not recommended, as it can lead to unpredictable performance and compatibility issues with system components.
The frequency of glycol replacement depends on factors such as system operating conditions, glycol type, and concentration.
Regular testing and monitoring of the glycol solution can help determine when it should be replaced.
Ethylene glycol and propylene glycol are both widely used in heating and cooling systems, but they have some critical differences.
Ethylene glycol generally provides better heat transfer and freeze protection compared to propylene glycol but is toxic and can be harmful if ingested or released into the environment.
In contrast, propylene glycol is considered non-toxic and environmentally safer, making it a preferred choice for applications where toxicity is a concern.
The optimal glycol concentration depends on factors such as the desired freeze protection level, heat transfer requirements, and system materials.
Generally, a glycol concentration of 30% to 50% is recommended for most heating and cooling systems.
It is essential to consult the manufacturer's guidelines to determine the appropriate concentration for your specific application.
Glycol is generally not recommended for use in potable water systems due to its potential toxicity, especially in the case of ethylene glycol.
In situations where freeze protection is necessary for potable water systems, alternative solutions such as heat tracing or insulation should be considered.
h2x will provide accurate friction loss calculations for your design based all of your chosen temperatures, fluid mixtures, and pipe properties.
In addition, h2x provides automated calculations for flow rates, velocities, pressures, pump duties, plant sizing, and recirculation systems mean that you can focus on your project's design instead of undertaking tedious calculations.
h2x's straightforward user interface helps engineers produce high-quality designs and work more efficiently, all while adhering to industry regulations.
The software has already been used to size millions of kilometres of pipes in projects across the world.
Book a demo or start your free trial today to discover how h2x can help you improve your design and calculation workflow.
The company is the world’s best Flooded Type Screw Type Chiller Manufacturer supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.