Keywords

1 Introduction

Heat exchangers, also known as heat transferring equipment, allow thermal energy to flow among two or additional liquids that are at various temperatures. There are many industries that use heat transfer devices, including power generation, food, process, and chemical, as well as manufacturing, electronics, air-conditioning, space, and refrigeration applications. In terms of global economics, energy, materials, and space, saving energy prompted an increase in efforts to develop more cost-effective heat exchange equipment. As a result of these efforts, the fundamental dimensions of heat exchange device for a certain thermal capability has been reduced [1]. Therefore, the more effective heat purposes in a heat exchanger are to reduce the heat exchanger’s size, which is necessary for thermal efficiency (capacity), to improve the capability and function of an current heat exchanger, or to diminish pumping power. In addition to improving heat transfer in heat transfer fluids and heat exchangers, many investigations have been carried out [2].

A device that enables the transfer of heat from one liquid to another is a heat exchanger. Heat exchangers can also be utilized for heating as well as cooling. To prevent cross-contamination, the liquids could be detached by a solid object, or maybe they’re in touch directly. In chemical plants, petrochemical plants, electricity generation and distribution, petroleum refineries and petroleum plants, natural gas processing, and sewage treatment, they are widely used [3].

A variety of heat exchanger issues can lead to poor productivity or, in certain situations, the complete shutdown of the industrial heat exchanger. The researchers use a variety of approaches to elucidate them. Because the most recent research supports utilizing nanofluids in heat exchangers, the work in question is taken into account. Other methods to avoid vibration problems, heat exchanger secretion, enhanced heat exchanger power usage, aisle separation (thermal leakage), and contamination should be considered in other articles [4].

But there is a quick brief of the difficulties that can happen in heat exchangers and why nano is a good idea. Contemplating the foregoing, the accessibility of superior-effectiveness heat exchangers is one of the most basic requirements in many businesses and research. As a result, the researchers suggested new approaches. The purpose of passive heat transfer mechanisms and variations in the rheological properties of fluids are being researched to find solutions to these problems. These techniques work by reducing the formation of a laminar sublayer, improving the number of interruptions, improving the efficient heat transfer surface, creating secondary flows or vortices, and improving fluid blending [5]. Many methods for increasing the heat transfer level in these methods have been proposed because heat exchangers show such a significant function in various electronics, transportation, manufacturing processes, including heat sources, and industrial processes. Most of these procedures rely on structural changes, such as increased thermal exteriors (fins), thermal exterior pulsation, and fluorescence. Heat transmission and compression in high-energy process equipment will be a challenge for these techniques to meet [6].

2 Improved Heat Transfer in Nanofluids Heat Exchangers

Plate type heat exchangers, double pipe heat exchangers, shell and tube heat exchangers, shell and helical coil heat exchangers, and fin type heat exchangers are just a few examples of the many types of heat exchangers available. In the tables below, we summarized heat transfer development using nanomaterials in different heat exchangers (Tables 1, 2, 3, 4 and 5).

Table 1 An overview of experimental work on a double pipe heat exchanger with nanofluids
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Table 2 Experimental studies on the efficiency of a Shell and tube heat exchanger employing various nanofluids are summarized
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Table 3 On the effectiveness of a Shell and Helical heat exchanger with various nanofluids, experimental studies are summarized here
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Table 4 Experimental investigations on the efficiency of plate type heat exchangers using various nanofluids are summarized
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Table 5 Experimental investigations on the effectiveness of a Finned tube heat exchanger using numerous nanofluids are summarized
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3 Conclusions

This paper reviews all the important papers on heat exchangers and nanofluids that have been published in the last few years (HEs). This comprehensive review looked at the outcomes of nanofluid on heat transfer in five various kinds of heat exchangers. The key findings are summarized below:

  • The use of nanofluid in all five heat exchangers has increased in the last decade as a result of its promise and a significant growth in thermal conductivity over the pure fluid.

  • The optimum volumetric concentration of nanofluid is a point at which the heat transfer rate increases as the volume concentration of nanoparticles rises.

  • It also increases viscosity and friction, lowering pumping energy. Almost all studies found that the desired thermal performance, heat transfer augmentation, entropy generation decline, and exergy destruction reduction were all better than the base fluids. Nanofluids for industrial use, on the other hand, necessitate high concentrations and kilos of nanoparticles, which have yet to be proven cost-effective.

  • It was also discovered that the working nanofluids temperature has a significant impact on heat exchanger efficiency improvement.

4 Recommendations for Future Work

  • The most research is required to ascertain how a nanofluid mixture affects a heat exchanger’s convective heat transfer coefficients, containing nanoparticle size, shape, pH variation, surfactant addition, sonication time, and agglomeration.

  • The heat transfer performance of a variety of hybrid nanofluids can be improved by changing the statistical constraints, such as plate thickness, plate pitch, corrugation pattern, and corrugation angle.

  • The effects of different surfactants on the thermal stability and properties of nanofluid mixtures.