Counter Flow Heat Exchangers & Working Principles

 A heat exchanger is a device that allows heat to be transferred from one medium to another quickly and efficiently. It is used to heat or cool a certain medium by utilizing another in the area. The technique is based on the fundamental science of heat transport from a hot to a cold medium. While anyone can change the temperature of a material by making physical contact with it or combining it with another liquid. A heat exchanger allows heat to be transferred without making physical contact.

It is made up of separate elements with a strong thermal conductivity that operate as heat transmission elements. They divide the two fluids while allowing heat to be transferred efficiently. The real heat transfer occurs in reaction to the relative flow of liquid in these separated parts, regardless of the size and shape of the exchanger. For effective heat transfer between the medium, a heat exchanger might have a contemporaneous, counter, or cross-flow arrangement.

Heat exchangers with the opposite fluid flow direction are classed as counter-flow heat exchangers. Shell and tube, plate, double-pipe, one-phase, or multi-phase counterflow heat exchangers are all options. Alaqua is processing equipment such as evaporator, distillation, crystallizer, spray dryer, solvent recovery, and heat exchanger equipment supplier worldwide based in the USA.

Different Types of Heat Exchangers

Heat exchangers are typically classified into two categories based on the flow arrangement: counter-flow and parallel flow heat exchangers, which are referred to as crossflow and inline, respectively.

Inline

Hot and cold fluids run in parallel in this type of exchanger. They're called counter-current counterflow heat exchangers if they move in the other direction, and are called parallel or co-current heat exchangers if they move in the same direction.

Due to the temperature differential between the fluids being uniform throughout fluid routes and the exchanger, counter-flow heat exchangers are more efficient than parallel exchangers.

Crossflow

The fluid in the cold and hot parts of a crossflow heat exchanger flows perpendicular to each other. This type of heat exchanger is more efficient than counterflow heat exchangers, and the entire heat exchanger can be contained within a box. The logarithmic mean temperature difference (LMTD) of this kind is larger than that of the inline type.

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Counter Flow Heat Exchanger

Heat exchangers with counterflows use flows that flow in the opposite direction of each other. Heat exchangers with counterflow layouts include shell and tube and twin pipes. A counter-flow architecture is the best design for a shell and tube or double-pipe exchanger because it provides for the most heat transfer between the fluids. Counterflow is more efficient than parallel flow, and the temperature of the cooling fluid outflow can be higher than that of the warmer fluid inflow.

Differences Between Parallel and Counter Flow Heat Exchangers

In terms of flow direction and heat transfer, parallel and counter flow heat exchangers are distinct. Both inlets are on the same side in parallel exchangers, while all of the outlets are on the other side. The intake has the greatest temperature differential, which reduces to the smallest at the outlets. When compared to the counter flow, it is the polar opposite.

As previously stated, the basic function of all heat exchangers is to transfer heat from hot fluids to colder fluids and to exchange energy between them. The heat transfer rate is greatly influenced by the surface of the plates, pipes, or whatever separates the fluids in a heat exchanger, and by increasing it, we may get a high rate of heat transfer for heavy-duty applications.

The amount of heat transfer and the fluids' output temperature determine the size and type of heat exchanger. The hot fluid output temperature is critical if the device's purpose is to cool, while the cold fluid output temperature is critical if the device's goal is to heat.

Merits and Demerits of Parallel Over Counter Flow Heat Exchangers

Parallel-flow arrangement: The hot and cold fluids enter from the same end, flow in the same direction, and exit from the same end in a parallel-flow system.

Counter-flow arrangement: Fluids enter at opposite ends, flow in opposite directions, and exit from opposite ends in a counter-flow arrangement.

A counter-flow heat exchanger transfers more heat than a parallel flow heat exchanger under the same conditions. The two heat exchangers' temperature profiles reveal two serious flaws in the parallel-flow design.

• Thermal strains are created by the considerable temperature differential at the ends.

• The temperature of the cold fluid leaving the heat exchanger is never higher than the temperature of the hot fluid at its lowest point.

When two fluids must be brought to almost the same temperature, a parallel flow heat exchanger is advantageous.

Alaqua is processing equipment including heat exchanger makers and suppliers worldwide to various environmental, pharmaceuticals, chemical, food, and power generation industries. We offer equipment fabrication, installation and commissioning, troubleshooting, retrofitting, personnel training, and field services for processing equipment as well. Request a quote today!