Glycol Chiller

What is a Glycol Chiller?

ChillerOne glycol chiller is an energy-saving industrial refrigeration device that uses ethylene glycol solution as the cooling medium. It continuously removes the heat from the equipment or process fluid through a circulating ethylene glycol solution and ultimately dissipates the heat into the environment by air cooling or water cooling to achieve precise temperature control.

Why Use the Ethylene Glycol Solution?

The main reason for using ethylene glycol is its excellent anti-freezing property. 

Mixing ethylene glycol with water can significantly lower the freezing point of the coolant, preventing it from freezing in sub-zero temperatures and causing equipment and pipelines to burst. 

Meanwhile, the boiling point of ethylene glycol solution is higher than that of water. Even when operating at higher temperatures, it will not cause cavitation, which expands its working temperature range. 

In addition, industrial ethylene glycol solutions usually contain corrosion inhibitors, which can protect the circulation pipelines and equipment from corrosion, ensuring the safe and stable operation of the entire cooling system.

Working Principles of Glycol Chillers

• Step 1: The low-temperature ethylene glycol solution, driven by a circulating pump, flows through the process or equipment that requires cooling. During this process, the ethylene glycol solution absorbs the heat from the process fluid or the equipment itself, causing the temperature of the ethylene glycol solution to rise. Subsequently, the warm ethylene glycol solution flows into the evaporator, transferring the heat it carries to the refrigerant. After being cooled by itself, it returns to the equipment for the next round of heat absorption.
• Step 2: In the evaporator, the low-temperature liquid refrigerant absorbs the heat of ethylene glycol and boils, transforming into a low-temperature and low-pressure gaseous state.
• Step 3: These low-temperature and low-pressure gaseous refrigerants are drawn in by the compressor and compressed into high-temperature and high-pressure gases.
• Step 4: The high-temperature and high-pressure refrigerant gas enters the condenser, releasing its heat to the air or water and condensing itself into a high-temperature and high-pressure liquid.
• Step 5: The high-pressure liquid refrigerant flows through the expansion valve, causing a sharp drop in pressure and temperature. It then turns back into a low-temperature and low-pressure liquid that is easy to evaporate and re-enters the evaporator to start a new cycle.

Core Components of the Glycol Chiller

Compressor

The compressor is the core power component of the refrigeration cycle of the ethylene glycol cooler. It absorbs the low-temperature and low-pressure refrigerant gas from the evaporator and compresses it to convert it into high-temperature and high-pressure gas, forming heat transfer throughout the system.

• Scroll Compressor: It uses a static vortex disk and a moving vortex disk to mesh with each other to form a series of continuously changing cavities, and continuously compresses the refrigerant gas by moving the cavities from the outside to the inside. It features smooth operation, low vibration, low noise and relatively simple structure, making it an ideal choice for ethylene glycol coolers in medium and low cooling capacity ranges.
• Screw Compressor: It adopts a pair of intermeshing helical rotors, which continuously change the volume of the rotor tooth slots to draw in, compress and discharge the refrigerant gas. It features a robust structure, a wide power range and a long service life, making it particularly suitable for large-scale industrial-grade ethylene glycol cooling projects. However, its initial installation cost is relatively high and it has more complex requirements for the lubricating oil system.

Condenser

The condenser receives high-temperature and high-pressure refrigerant gas from the compressor and uses cooling media such as air or water to release the heat it carries into the external environment, causing the refrigerant to condense from a gaseous state to a high-temperature and high-pressure liquid state.

• Air Cooled Condenser: It forces the ambient air to flow over the surface of its finned coil through a fan, thereby removing the heat carried by the high-temperature and high-pressure refrigerant inside the tube and condensing it into a liquid state. This type of condenser does not require additional cooling water and is easy to install. However, its heat dissipation efficiency is greatly affected by the ambient temperature, and its energy efficiency will decrease during the hot summer.
• Water Cooled Condenser: It uses flowing cooling water as the cooling medium to exchange heat with the high-temperature refrigerant inside the evaporator. It features high heat exchange efficiency, stable operation, and a lower condensing temperature, which is particularly suitable for large-scale, continuous operation industrial projects with circulating water systems. However, it requires the installation of cooling towers and water treatment systems, resulting in high initial investment and relatively complex maintenance.

Evaporator

The evaporator is usually used for heat exchange. The low-temperature and low-pressure liquid refrigerant exchanges heat with the warm ethylene glycol solution in the evaporator. After absorbing heat, the refrigerant evaporates into a gaseous state, thereby cooling the ethylene glycol solution to the target temperature.

• Shell and Tube Evaporator: Its design usually features the refrigerant evaporating between the tube bundles within the shell, while the ethylene glycol solution flows inside the tubes. This structure endows it with high pressure-bearing capacity, strong anti-fouling ability, and relatively convenient maintenance and cleaning. It is the preferred choice for many standard ethylene glycol coolers, especially suitable for industrial environments with complex working conditions or high durability requirements.
• Plate Evaporator: It is composed of a series of corrugated thin metal plates stacked together, forming a large heat exchange area through complex plate flow channels, which enables efficient counter-current heat exchange between the refrigerant and the ethylene glycol solution. Its structure is compact and its heat exchange efficiency far exceeds that of the shell and tube type. However, it has higher requirements for water quality and filtration, and its pressure-bearing capacity is usually not as good as that of the shell and tube type.

Expansion Valve

The expansion valve is located between the condenser and the evaporator. By precisely controlling the flow of the refrigerant and throttling and depressingling it from a high-temperature and high-pressure liquid to a low-temperature and low-pressure gas-liquid mixture, it provides conditions for the refrigerant to absorb heat, evaporate and recirculate in the subsequent evaporator.

Electrical Control System

The electrical control system, through controllers, sensors and protection devices, enables you to automatically monitor and adjust the operating status of the glycol chiller, such as temperature and pressure, which ensures that your equipment can operate safely, stably and efficiently according to the set parameters.

Characteristics of Glycol Chillers

Operate in Low-Temperature Environment

By adjusting the concentration of ethylene glycol, the freezing point of the solution can be reduced to tens of degrees below zero, ensuring that the cooling system of the chiller can operate safely and stably in a low-temperature environment and avoiding the risk of pipeline and equipment expansion and cracking caused by solution freezing.

Wide Operating Temperature Range

Ethylene glycol solution not only lowers the freezing point but also raises the boiling point, which enables our cooling system to operate reliably within a wide temperature range from minus low temperatures to above zero high temperatures, while also reducing the occurrence of cavitation at high temperatures.    

Reliable Cooling Device

Glycol chillers usually adopt indirect cooling methods. The refrigerant circulates in an independent closed loop, cooling the ethylene glycol solution through the evaporator and then using the ethylene glycol solution to cool the target equipment. This cooling method isolates the precise refrigeration system from the process end, which effectively protects the expensive core components and extends the lifespan of your equipment.

Flexibility

Our ethylene glycol chiller system is flexibly designed. You can choose different component combinations based on your different cooling capacity requirements and on-site cooling conditions, such as air-cooled or water-cooled condensers, shell and tube or plate evaporators, scroll or screw compressors. We can provide you with customized solutions.

Energy-Saving and Reliable

Our glycol chillers typically employ high-efficiency compressors and optimally designed heat exchangers, which can significantly enhance conversion efficiency, achieve precise temperature control, and thereby reduce operational energy consumption. In addition, by isolating the core refrigeration circuit from the harsh process environment, component wear and failure rates are reduced, which ensures that your equipment can operate stably for a long time in harsh industrial conditions.

Easy to Install and Maintain

Many of our models have completed the assembly and testing of core components before leaving the factory. You only need to connect basic interfaces such as pipes and power supply to quickly put them into operation, greatly simplifying your installation process. In terms of daily maintenance, all key parameters of the system are easy to monitor, which effectively reduces the complexity and cost of your long-term maintenance.

How Do You Choose the Right Glycol Chiller?

Clarify Your Needs

• Cooling Capacity: You need to calculate the cooling capacity required for your application based on the heat release and heat generation power of the reaction vessel. This is your primary basis for selection.
• Temperature Range: You need to determine the temperature that the cooling equipment is required to reach and the minimum temperature of the liquid that the cooler can provide.
• Ethylene Glycol Solution Concentration: You need to ensure that the freezing point of the solution is 5-10°C lower than the minimum ambient temperature. Generally, the higher the concentration of ethylene glycol solution, the lower the freezing point.
• Flow and Pressure: You need to calculate the minimum flow rate required based on the cooling capacity and temperature difference, and determine the pumping pressure needed by the system to select the appropriate circulating pump.

Evaluate the Installation Environment

• Condenser Type: Air-cooled condensers are suitable for water-scarce and well-ventilated environments. They are easy to install and take up little space, but they are relatively noisy. Water-cooled types are suitable for occasions with water sources and high efficiency requirements. They take up more space and are more complex to maintain, but they have a higher and more stable operating energy efficiency ratio.
• Ambient Temperature: This directly affects the condensation effect and refrigeration capacity of the equipment.
• Space Limitation: You need to check the space at the installation site to ensure that our equipment can be smoothly positioned and there is sufficient ventilation and heat dissipation space.

Select Configuration

• Compressor Type: Scroll compressors are suitable for medium and small cooling capacities. They feature high energy efficiency, stable operation, low noise and easy maintenance. Screw compressors are suitable for large cooling capacities, which feature strong durability and a long service life.
• Evaporator Type: Shell and tube evaporators are resistant to high pressure, resistant to dirt, easy to maintain and clean, and have wide applicability. Plate evaporators have a compact structure and extremely high heat exchange efficiency, but they have high requirements for water quality, are prone to clogging and are not resistant to high pressure.
• Intelligent Control: Choosing a model equipped with an intelligent control system can help you achieve precise temperature control, fault alarm and remote monitoring.