What is plate heat exchanger? What are the advantages and disadvantages of plate heat exchanger? If you have been searching for answers about what plate heat exchanger is, then you are at the right place. This article will be discussing all you need to know about the advantages and disadvantages of plate heat exchanger.
Plate heat exchanger is an important component of heat transfer, which is used to transfer heat between two different materials.
The actual functioning of the plate can be explained as follows: when a fluid flows over the inner surface of a flat circular disc, it will move around and uniformly spreads out on its surface. The speed at which the fluid moves depends on the change in temperature (ΔT).
The outer surface of disc gains energy from the fluid because with increasing temperature in fluid, its energy content increases, and it can move faster. Therefore, this outer surface will increase the temperature distribution about itself.
What Is Plate Heat Exchanger?
A plate heat exchanger is used in industries to transfer heat between two fluids. It has plates that are made of metal with grooves that circulate the fluids. A pump can be used to circulate the fluids through the plates of the heat exchanger.
In a plate heat exchanger, there are two main types of plates: single pass and double pass. A double pass plate-type heat exchanger is one that transfers heat twice across each side of the same component, while a single pass type transfers heat once.
The first one has better efficiency and requires less space, but it also requires more time for pumping fluid through its tubes.
The objective of any heat exchanger is, in simple terms, to make a hot fluid colder and/or make a cold fluid hotter, specifically without mixing them.
The fluids that flow through the heat exchanger are used for heating and cooling processes in industries. The heat exchanger is also called a condenser as it is used to cool the water/fluid that passes through it.
Because of this, it is important to have a plate heat exchanger in areas where industries do not have cooling facilities.
By exploiting certain concepts such as conduction, entropy, and fluid mechanics, these devices can transfer the heat from one flow to another and can be used as condensers, evaporators, and much more.
In the case of cooling fluids, the heat exchanger adds energy that causes a phase transition from gas to liquid and then to solid. In particular, the coolant passes through a tube bundle, which is made up of thin tubes.
The tubes have fins that cool the fluid by exposing it to air. The fins also separate each tube from its adjacent ones, thereby minimizing their effect on the other tubes.
As such, this mechanical separation minimizes heat transfer between neighboring tubes and increases the overall efficiency of heat transfer in a heat exchanger device.
On the other hand, if there are too many tubes in the tube bundle, then one of the tubes can be blocked by its adjacent neighbors. This is called impedance.
A double pass plate heat exchanger consists of a main portion, which is made up of a base plate and flanges, and a second plate attached to it through tubes. The first plate serves as a heat exchanger for fluid that passes through it; however, fluids cannot pass through tubes in the second plate.
When this type of heat exchanger is used, not all the fluid molecules will pass though one tube but will go through several tubes over time.
This is because of the aforementioned phenomenon: fluid will move from one tube to another, and thus can take a longer time to pass through the heat exchanger.
In order to increase efficiency, there are two solutions: First, you can use a device with more tubes in a single pass plate heat exchanger. Second, you can utilize several parallel paths for the fluid in a double pass device.
How Do Plate Heat Exchanger Works?
The plate heat exchanger works by transferring heat from one hot fluid to another. The main component of the plate is the plate itself, which is made up of very thin metal sheets. The material that makes up the plates is nickel because it has a high thermal conductivity.
These sheets are also coated with special chemicals that make it more rigid and avoid bending once they get overheated. The plates are then fastened onto a supporting frame through screws that help keep them aligned in different directions.
The frame holds the plate to an armature with two sets of tube tubes. The armature is then fastened to a base and can be connected with the heat source through pipes. There are also other parts involved in the work of a plate heat exchanger.
There are moving ball bearings that minimize friction and allow for twisting, turning, and spinning of the plates around their axes, as well as check valves that enable fluid flow in one direction only.
Plates with fins are also used in order to expose the fluid to air, which helps cool it more effectively. The plates are also further insulated so that they can work at a safe temperature while handling high temperatures of the fluids they are working with.
The working of plates in a heat exchanger is actually similar to how heat transfer happens in an environmental radiator. The difference, however, is that these radiators transfer heat from liquids to gases while the plate heat exchanger works on transferring heat from gases to liquids.
Now we have gone through what plate heat exchanger is and how it works, let’s move on to the advantages and disadvantages of plate heat exchanger.
Advantages And Disadvantages Of Plate Heat Exchanger
Here we will be looking into the advantages and disadvantages of plate heat exchanger but firstly, we will be diving to the advantages of plate heat exchanger and later to its disadvantages.
The advantages of plate heat exchanger are as follows:
1. High Heat Transfer Coefficient
Plate heat exchanger has a high thermal conductivity, which means it can transfer heat more efficiently than other types of heat exchangers. Plate possesses good resistance to corrosive substances and high operating pressures as well as reasonable cost.
2. Great adaptability
The required heat transfer area can be achieved by increasing or decreasing the heat exchanger plates.
Plate heat exchanger can easily be customized to many applications and environments. They are flexible and durable, which makes them a great choice in the process industries. Their modular design also allows the use of relative short sections while remaining efficient.
3. It Is Simple And Easy To Maintain And Clean
Plate heat exchanger is the simplest heat exchanger and performs well under tough operating conditions. Plate heat exchanger can be easily cleaned after use and maintained easily.
It is also portable, which means you can install it wherever you need it without any major problems. Plate heat exchanger is a reliable device that can be used for different performance requirements.
4. Multiple Duties in a Single Unit
Since plate heat exchanger has multiple functions, it can be used for several applications at a time. The modular design allows for several different configurations of the device.
The moving and rotating parts are housed in a single unit, making it easy to access for maintenance and repair.
Moving on, let’s go into the disadvantages of plate heat exchange.
Some of the disadvantages of plate heat exchange includes:
1. Higher Initial Cost
Plate heat exchanger is relatively more expensive than other heat exchangers because it has a higher quality, but there are several factors to take into account.
The cost of plate heat exchanger depends on its quality, size, and performance level as well as the amount of fluids that need to be passed through it. We can compare the initial cost for this type of heat exchanger with others once we know the true operating costs and what the device is used for.
2. Poor Sealing And Easy To Leak
Plate heat exchanger is made up of thin and fragile sheets, which means that they can easily break when they come into contact with something sharp.
Plate heat exchanger also cannot be used in environments that are very corrosive because the fluid passing through it will slowly eat up the plates. This makes it more susceptible to leaks and breaks.
3. Hard To Find Leakage
This type of heat exchanger offers no leak checks or any other forms of protection for the components. The fluids passing through this unit are under high temperatures, so there is a high risk of leakage.
It is hard to find leakage in the plate heat exchanger because there are many areas that can be affected. In order to spot a leak, you need to check each part separately in all directions.
While plate heat exchanger is a reliable and versatile device, there are some disadvantages of plate heat exchanger. Nonetheless, plate heat exchanger is generally easier to maintain and clean, as well as easy to install.
Plate heat exchanger has a high heat efficiency and can easily be customized to various temperatures and applications. Plate heat exchanger is also light and portable, which makes it a great addition to any chemical processing system.
Overall, plate heat exchange is a great option because it can be used in various industries and can be customized for specific needs easily.