Liquid-to-air heat exchangers
A liquid-to-air heat exchanger is a device designed to transfer heat from a liquid medium to the surrounding process air. It is commonly used to heat or cool air that is circulated in industrial processes.
This article will tell us more about liquid-to-air heat exchangers, including how they work, where we find them, and why they are essential to some industries.
What is a liquid-to-air heat exchanger?
A liquid-to-air heat exchanger consists of a series of tubes or channels through which the liquid flows, and where those tubes/channels are exposed to an airflow where heat energy is exchanged. This design facilitates the exchange of thermal energy between the liquid and the air, transferring heat from the liquid to the air or vice versa.
This type of heat exchanger is found in industrial processes, automotive cooling systems, air conditioning units, and electrical cabinet cooling, to name a few. By utilising the temperature difference between the liquid and the ambient air, a liquid-to-air heat exchanger efficiently dissipates heat and helps maintain the desired operating temperature of the treated environment.
How it works
How does a liquid-to-air heat exchanger work? Here’s a simplified explanation.
1. Liquid flow
The liquid, such as water or oil, enters the heat exchanger and is directed to flow through tubes or channels in a pre-determined pattern. These tubes and often fins are designed to maximise the surface area available for heat exchange.
2. Heat transfer
As the liquid flows through the tubes, it exchanges thermal energy to the tube walls through conduction. The tube walls and fins act as conductors and convectors, facilitating heat transfer from the liquid to the environment.
Air is either forced or drawn over the external surface of the tubes or passively circulates. The air absorbs the heat from the tube walls through convection and conduction. Fans or blowers may be used to enhance heat transfer but with higher operating costs.
4. Heat exchange
Heat is transferred from the liquid to the air as the heated tubes come into contact with the cooler air. The liquid gradually loses heat, leading to its cooling, while the air gains heat and becomes warmer. Or the inverse in a cooling application.
5. Heat recovery
In some applications, heat exchangers are used to recover heat from a process. The heated air, now carrying the transferred heat, is typically expelled from the heat exchanger through an exhaust system. This allows the heat to dissipate into the surrounding environment.
A liquid-to-air heat exchanger enables efficient heat transfer by utilising the large surface area of the tubes and fins, and the temperature difference between the liquid and the air.
The specific design and configuration of the heat exchanger depend on the application and desired heat exchange capacity. At Sterling TT, we design heat exchanges with the best materials for the job to meet your exact needs. Find out more on our heat exchanger conceptual design page.
Types of liquid-to-air heat exchanger
Liquid-to-air heat exchangers can come in many forms. Here are some of the most common ones:
Shell and tube heat exchanger
Shell and tube heat exchangers are extensively employed in industrial settings to facilitate efficient heat exchange between fluids. These exchangers comprise an outer shell, serving as the primary vessel, and an inner arrangement of tubes through which the fluids circulate. Heat transfer occurs across the tube walls, enabling the exchange of thermal energy between the fluids.
Finned tube heat exchanger
Finned tube heat exchangers have fins attached to the outer tube of the exchanger. The liquid flows through the tubes, and air passes over the fins. The fins increase the surface area, facilitating enhanced heat transfer between the liquid and the air. Find out more about enhanced heat exchangers with extended fins.
Applications of liquid-to-air heat exchangers
Various examples of liquid-to-air heat exchangers are used in different industries and applications. Here are some common examples.
The radiator in a vehicle’s cooling system is a liquid-to-air heat exchanger. It transfers heat from the engine coolant to the surrounding air to keep the engine operating within the optimal temperature range.
Oil coolers are used in various applications, including power stations, automotive engines, hydraulic systems, and industrial machinery. They transfer heat from the hot oil to the surrounding air, maintaining the proper operating temperature of the oil.
Charge air cooler
Also known as an intercooler, a charge air cooler is used in turbocharged or supercharged engines. It cools down the compressed air before it enters the engine, improving performance and efficiency by increasing the air density.
Liquid cooling systems for electrical cabinets
Liquid-to-air heat exchangers are often used in electrical cabinet cooling systems such as ships or high-performance computing systems. They remove heat generated by the electronics and dissipate it into the surrounding air.
These are just a few examples of liquid-to-air heat exchangers, and there are many more specific applications and variations depending on the industry and requirements.
Industrial waste heat recovery
For this application, high-temperature shell and tube heat exchangers are used.
Benefits of liquid-to-air heat exchanger
Liquid-to-air heat exchangers offer several benefits in various applications. Here are some advantages of using a liquid-to-air heat exchanger:
Efficient heat dissipation
Liquid-to-air heat exchangers provide efficient cooling capabilities by transferring heat from the liquid medium to the surrounding air. The large surface area exposed to the air allows for effective heat exchange, ensuring optimal cooling performance.
These heat exchangers are often designed to be compact and lightweight, making them suitable for installations where space is limited. Their compact size allows for easy integration into different systems or equipment without occupying excessive space.
Liquid-to-air heat exchangers can be utilised in various applications across various industries. They are commonly used in automotive cooling systems, electrical cabinet cooling, HVAC systems, industrial processes, and more. This versatility makes them adaptable to different cooling requirements.
Implementing a liquid-to-air heat exchanger can be more cost-effective than alternative cooling methods. They are typically less expensive to install and maintain than complex systems like liquid-to-liquid heat exchangers or refrigeration-based cooling systems.
Maintenance of liquid-to-air heat exchangers is relatively straightforward. Cleaning the external surface of the heat exchanger to remove any dust or debris that may hinder airflow is typically sufficient to maintain its performance. This simplicity reduces downtime and maintenance costs.
Liquid-to-air heat exchangers can contribute to energy efficiency by enabling heat recovery. In specific applications, the heat extracted from the liquid can be redirected and utilised for other purposes, such as preheating incoming fluids or space heating, reducing overall energy consumption.
Overall, liquid-to-air heat exchangers offer efficient cooling, versatility, cost-effectiveness, and ease of maintenance, making them a preferred choice in many industries for effective heat transfer and temperature control.
Sterling TT designs and manufactures liquid-to-air heat exchangers
At Sterling TT, we have over 100 years of experience designing and manufacturing heat exchangers for various industries. So, if you’re looking for a specialist in heat exchange solutions, we are your expert.
Get in touch today, and an experienced member of our team will be in contact with you.