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With the development of economy, the shortage of energy and environmental problems is increasingly prominent. Phase change energy storage technology can effectively solve the energy mismatch in space and time. Phase change cold storage materials are classified into organic materials, inorganic materials and composite materials, which usually have d...
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... The application was reported as the thermal management of any system. Xu et al. [173] conducted numerical studies on the PHP-PCM hybrid system for the application of cold storage. Cold sources at various low temperatures (as low as -50°C) were attached to the condenser region. ...
Pulsating Heat Pipe (PHP) is an emerging efficient heat transfer device, that transfers heat passively through oscillating motions of liquid slugs and vapor plugs within the device. PHP is of high effective thermal conductivity with great potential in heat transfer management for various applications. The objective of this review paper is to summarize and analyse the applications of PHP in various fields that have been reported in the open literature, emphasizing on studies reported in past half decade. The thermo-hydraulic behaviour of PHP is influenced by numerous geometric and operational parameters, which are discussed in detail in the first part of the paper. The thermal performance of the PHP under rotation condition, which is seldom discussed in previous review articles, is also discussed. These parameters act individually and in tandem to alter the performance of PHP, which makes its prediction extremely difficult. However, the benefit of numerous influencing parameters is that they can be altered to make PHP suitable for various applications. These highly variable configurations make PHP suitable for applications such as the transfer of absorbed solar energy to the location of interest, waste heat recovery, thermal management of electric vehicle batteries, fuel cells, cooling of electronic components etc. PHPs are recently being studied for applications in cryogenics and cooling of cutting tools in the machining process also. In addition, novel applications of PHP such as high-performance fins for heat exchangers, cooling of building roofs etc. are also being reported. All these applications of PHP reported in the open literature are reviewed and summarized in the present article.
... The Pulsating Heat Pipe (PHP) was proposed by Akachi [1] in 1990. From that point forward it was considered to have brilliant application possibilities [2] in areas of solar energy utilization [3][4][5][6][7], waste heat recovery [8][9][10], electronics cooling [11][12][13], space thermal management [14,15] and other fields [16][17][18] due to its distinct advantages. PHPs are widely used for cooling tools that have compact sizes such as electronic devices. ...
In this Paper, a Flexible Pulsating Heat Pipe (FPHP) was experimentally tested to evaluate the effect of foldability on the start-up, overall thermal resistance and evaporator temperature. Evaporator and condenser sections were made of 9 turn copper capillary of 2 mm inner diameter. Adiabatic section was made of a silicon rubber tube with an inner diameter of 3 mm. Deionized water with 50% filling ratio was used as working fluid. Heating power range kept was 10–100 W. Four different structural styles (Vertical, 45-Degree, 60-Degree and 90-Degree) created by deforming adiabatic section were experimentally tested and compared. The results show that FPHP showed efficient performance in vertical style. The minimum thermal resistance found is 0.65 °C/W for vertical style when heating power is 99.88 W. Deformation of adiabatic section degrades start-up and thermal performance of FPHP which depends on the deformation extent. The highest increase in thermal resistance for 90-Degree style is 29.30% for the heating power of 99.88 W when compared with vertical style. Start-up heat input observed is 50.52 W for vertical and 45-Degree styles while it is 60.29 W for 60-Degree and 90-Degree styles. Start-up evaporator temperature increases when the structural style is changed from vertical to 90-Degree.
A heat transfer apparatus, known as a heat pipe (HP), offers distinct advantages, primarily in its exceptional thermal efficiency for heat transfer. HP is used to transfer heat over long distances with minimal temperature change. Before executing HP in the real-life applications of such HT devices, the principal step exhibited in the HP is the numerical simulation. It has the potential to yield efficient outcomes in terms of both time and cost dynamics. This review presents a comprehensive analysis of the opportunities and challenges identified in HP through the use of numerical modeling, analysis, and experimental simulations. At first, the classification like two-phase closed thermosyphon, annular, loop, pulsating, micro- and miniature, vapor chamber, variable conductance and sorption-based HP are discussed with governing equations, boundary conditions and assumptions. This review also explores numerous approaches for simulating the analytical model of high-performance (HP) systems. By then, the fluid flow modeling in the HP is discussed. At last, the critical challenges exhibited in the extensive application of HP is studied for future work.
After the machine tool works continuously, the temperature of the hydraulic system continues to rise, which affects the work efficiency of the machine tool. Therefore, it is very important to control the temperature within a reasonable range. This paper proposes an improved scheme to replace a single fan with dual fans to improve the heat dissipation capacity of the radiator. Starting from the principle of heat exchange between oil and air, the relationship between the oil temperature and the wind speed on the face of the heat exchanger is derived, and the theoretical basis of the cooling system is given. Combined with logic control, the fan has the advantages of fast action, high efficiency and low energy consumption, which ensures the efficient and reliable operation of the machine tool. A one-dimensional simulation model of the thermal hydraulic system is established, and the heat generation and heat dissipation power of each element are calculated. Among them, the heat dissipation of the radiator is the largest, accounting for about 55% of the total heat dissipation. The experimental results show that the optimal fan speed is 3200 r/min and the flow rate is 0.2 m3/s at 26 °C. The thermal balance temperature of the hydraulic system is reduced from the original 65 °C to 58 °C, and its cooling capacity meets the requirements of a high-altitude and high-temperature environment.
