OREANDA-NEWS. September 18, 2012. Panasonic Corporation today announced that it has developed a loop heat pipe (LHP) cooling system equipped with the company’s unique Jet Explosion Stream Technology[1] (JEST), which uses a high-speed jet stream[2] generated by the rapid expansion of the refrigerant which significantly enhances the cooling performance.

Using this technology, the heat pipe[3] has become ready for heat density[4] of up to 390 W/cmІ (results from internal experiments[5]). This cooling system can be applied to equipment such as power semiconductors for power conversion systems and supercomputer processing units, where the heat density is expected to rise.
Effects

The high performance cooling at a density of up to 390 W/cmІ has been achieved by applying the technology of generating a high-speed jet stream created by the expansion of the refrigerant. This is about 2.3 times the heat density that can be cooled by existing heat pipes, allowing for cooling systems smaller in size and higher in performance. In addition, this system does not require a drive unit to circulate the refrigerant, contributing to energy saving of the target equipment.
Features

The developed cooling system has the following features.
High performance cooling at a heat density 2.3 times that of heat pipe type makes it possible to reduce the size of the heat receiving section
Capable of long-distance heat transfer without using a pump or other drive unit to circulate the refrigerant, contributing to energy saving
Technologies

The developed JEST type LHP cooling system (JEST type LHP) has been achieved by the following new technologies.
High-speed jet stream generation technology using the rapid expansion of the refrigerant
 This technology optimizes the shape of the surface subjected to heat from the heat source and the refrigerant supply system, and uses the high-speed jet stream generated by the expansion of the refrigerant to efficiently dissipate heat from the heat receiving surface.
Technology for automatically supplying refrigerant to the heat receiving section
 This technology optimizes the difference in pressure before and after the check valve and the hydraulic head pressure[6], which are determined by the pipeline resistance and the volume of refrigerant in the cooling system, according to the amount of heat generated.
Background

Heat pipes have been used for cooling small electronic equipment; however, the amount of heat transported per pipe has been limited, making it unavoidable to increase the size of the equipment in order to deal with the rise in the amount of heat generated.
 Cooling systems using a pump to forcibly circulate the refrigerant can respond to the rise in the amount of heat generated by increasing the flow rate of the refrigerant to be circulated in the heat-generating section. However, the power consumption of the pump also increases. In line with the prediction that heat generated by electronic equipment will increase, there has been a rising demand for energy-efficient cooling systems capable of responding to the increase in the amount of heat generation without increasing the equipment size.