Solid-state cooling by elastocaloric polymer with uniform chain-lengths

Although the elastocaloric effect was found in natural rubber as early as 160 years ago, commercial elastocaloric refrigeration based on polymer elastomers has stagnated owing to their deficient elastocaloric effects and large extension ratios. Herein, we demonstrate that polymer elastomers with uniform molecular chain-lengths exhibit enormous elastocaloric effects through reversible conformational changes. An adiabatic temperature change of −15.3 K and an isothermal entropy change of 145 J kg−1 K−1, obtained from poly(styrene-b-ethylene-co-butylene-b-styrene) near room temperature, exceed those of previously reported elastocaloric polymers. A rotary-motion cooling device is tailored to high-strains characteristics of rubbers, which effectively discharges the cooling energy of polymer elastomers. Our work provides a strategy for the enhancement of elastocaloric effects and could promote the commercialization of solid-state cooling devices based on polymer elastomers.

Design of a Scalable, Flexible, and Durable Thermoelectric Cooling Device for Soft Electronics Using Kirigami Cut Patterns

A flexible, soft thermoelectric cooling device is presented that shows potential for human cooling applications in wearable technologies and close-to-body applications. Current developments lack integration feasibility due to non-scalable assembly procedures and unsuitable materials for comfortable and durable integration into products. Our devices have been created and tested around the need to conform to the human body which we have quantified through the creation of a repeatable drape testing procedure, a metric used in the textile industry. Inspired by mass manufacturing constraints, our flexible thermoelectric devices are created using commercially available materials and scalable processing techniques. Thermoelectric legs are embedded in a foam substrate to provide flexibility, while Kirigami-inspired cuts are patterned on the foam to provide the drape necessary for mimicking the performance of textile and close to body materials. In total, nine different configurations, three different fill factors and three different Kirigami cut patterns were fabricated and inspected for thermal characterization, mechanical testing, flexibility and drape. Our studies show that adding Kirigami patterns can increase the durability of the device, improve the flexibility, decrease the drape coefficient, and have <1% of impact on cooling performance at higher fill factors (>1.5%), reaching temperature differences up to 4.39 ± 0.17°C between the hot and cold faces of the device. These thermoelectric cooling devices show great flexibility, durability, and cooling for integration into soft cooling products.

Study on Performance of the Thermoelectric Cooling Device with Novel Subchannel Finned Heat Sink

The thermoelectric refrigeration system is an application of the Peltier effect, and good refrigeration performance is dependent on effective heat dissipation performance. To enhance the cooling performance of the thermoelectric system, this paper designs a new type of finned heat sink, which does not change the overall size of the thermoelectric system. The performance of the refrigeration system under the new fin is tested by experiments under various conditions. During the experiment, the cooling wind speed, the temperature of the hot and cold side of the TEC, the power consumption of the fan, and other parameters were directly recorded through the measuring instrument. The results show that the use of new finned heat sinks can improve the COP of the thermoelectric refrigeration system. Within the scope of the study, the thermal resistance of the new fins can be reduced by , and the system COP value can be increased by . In addition, increasing the cooling wind speed can further reduce the cold side temperature. Within the research range, the lowest temperature can reach , but the power consumed by the fan is of that of the conventional fin heat sink refrigeration device.

Engine Cooling Device of New Energy Vehicle

With the environmental pollution and the shortage of oil resources becoming more and more serious, the development and application of new energy vehicles have attracted more and more attention. Engine is an important part of new energy vehicles, and its performance has a great impact on the vehicle. Compared with traditional industrial motors, new energy vehicle engines have higher requirements on power density, and the improvement of power density poses new challenges to the design of motor cooling system. The purpose of this paper is to study the engine cooling device of new energy vehicles and improve the overall performance of the vehicle. The main research content of this paper is to lay a foundation for the theoretical basis of the engine cooling device, elaborate the working principle of the motor cooling system and the loss of the motor in operation. Then, the heat dissipation system of permanent magnet synchronous motor based on heat pipe is studied experimentally. Aiming at the problem of only considering the temperature rise and ignoring the pressure loss in the flow channel design, a flow channel design method considering the motor temperature rise and the flow channel pressure loss is proposed, and the motor flow channel is optimized. The test results show that the maximum temperature rise at the end is close to 16.56 °C, which is in good agreement with the simulation results. It shows that the heat pipe based heat dissipation system can effectively reduce the temperature rise of motor winding, which provides a new idea for the heat dissipation design of permanent magnet synchronous motor