Impact of the Magnetic Field on the Performance of Heat Pipes Driven by a Photovoltaic–Thermal Panel with Nanofluids

A two-dimensional dynamic heat transfer and fluid flow model was developed to describe the behavior of photovoltaic cells and the performance of a hybrid solar collector photovoltaic–thermal solar panel system. The system was assessed under different magnetic field Gauss forces. Nanofluids were used to drive the heat pipes in a thermal panel under different conditions, such as levels of solar irradiance and different boundary conditions. The model was developed based on the equations of the dynamic conservation of mass and energy, coupled with the heat transfer relationships and thermodynamic properties, in addition to the material properties under different magnetic Gauss forces. Comparisons were made with the literature data to validate the predictive model. The model reliably predicted the key parameters under different nanofluid conditions and magnetic fields, and compared well with the existing data on the subject.

Performance of the wall implanted with heat pipes on indoor thermal environment

In order to improve the utilization of solar energy absorbed by the building wall, a passive building technology, that is the wall implanted with heat pipes, had been proposed. In the present study, two rooms with the same environmental conditions were built, and the one with a wall implanted with heat pipes installed was taken as a test room and the other as a control. The dynamic heat transfer characteristics of a wall implanted with heat pipes in transition season and its impact on indoor thermal environment were studied experimentally. The results showed that the application of a wall implanted with heat pipes could increase the indoor temperature by about 0.5 °C and would assert a positive influence on the vertical distribution of temperature. The PMV-PPD values of two rooms were calculated to compare and evaluate the improvement in thermal comfort, and the results indicated that the wall implanted with heat pipes reduced the dissatisfaction rate by more than one seventh in comparison to the indoor thermal environment. Also, it enhanced the PMV value. Therefore, wall implanted with heat pipes as an auxiliary heat source has a good effect on the indoor thermal environment during the transition season.

Impact of Magnetic Field on the Dynamic Performance of Photovoltaic-Thermal Panel with Nanofluids

The performance of a hybrid solar collector photovoltaic-thermal solar panel system under a magnetic field using nanofluids was presented hereby. A two-dimensional dynamic heat transfer and fluid flow model was developed to describe the behavior of the photovoltaic cell-thermal panel at different conditions such as solar irradiance, nanoparticles, different magnetic field gauss forces. different material properties, and boundary conditions. The model has been established after the dynamic mass and energy equations coupled with the heat transfer relationships, and thermodynamic properties as well as material properties under different magnetic gauss forces. Comparisons were made against literature data for validation purposes of the predictive model. The model fairly predicted the key parameters under different nanofluids conditions, magnetic fields, and compared well with existing data on the subject.

Experimental Study on the Dynamic Heat Transfer Characteristics of a Mechanically Pumped Two-phase Cooling Loop

The present research designs a mechanically pumped cooling loop system and conducts an experimental investigation on the dynamic heat transfer characteristics of the system. The effects of the start-up heat load and heat load variation on the dynamic characteristics of the system are analyzed. The results indicate that during the start-up period, as the heat load rises, the temperature overshoot and duration time of adjustment decrease, while the pressure oscillation amplitude increases. During the regular operation period, as the heat load increases, the temperature at the evaporator outlet gradually increases until it approaches the saturation temperature and then remains constant. The pressure evolution at the evaporator outlet can be divided into four stages: steady state, drastic oscillation, damped oscillation, and slight oscillation.