Influence of the Gas Volume in the Void Tube Connecting Compressor and Inertance Tube on the Oscillating Flow in an Inertance Tube Phase Shifting System

AbstractInfluencesof thegas volumein the void tube (connecting tube), connecting compressor and inertance tube, on the oscillating flowcharacteristics are experimentally investigated. Four void tubes, whose volumes are different from each other, are chosen to connect the compressor and the inertance tube respectively. Piston displacement of the compressor and dynamic pressure at the outlet of the compressor are measured by a laserdisplacement sensor and a quartz pressure sensor respectively. This investigation focuses on the piston displacement and mass flows at three special positions of the experimental system.The change of the amplitudes and phase angles of the piston displacement and the three mass flows caused by varying the void tubes with different dynamic pressures and frequencies are studied. This investigation is helpful to study the influence ofthe gas volumein the connecting parts of an inertance tube pulse tube cryocooler, such as transfer tube, cold finger and pulse tube, on oscillating characteristics of the cooler

data package

Please read traits illustration in the data package

Thermodynamic Performance of Molten Salt Heat Storage System Used for Regulating Load and Supplying High Temperature Steam in Coal-Fired Cogeneration Power Plants

In order to accept more electricity from renewable energy, cogeneration power plants are considering to reduce electricity production, which affects the heat supply. Here we present a molten salt heat storage system for coal-fired cogeneration power plants, which can supply high temperature steam to users and decouple the heat and electricity production. The first and second law-based analytical models for the cycle and a real device are built. Two water input methods are taken into account. The results show that the high and low temperatures in the two molten salt tanks influence the design of the components and the entropy generation distribution significantly. The pinch temperature difference in the discharge duration limits the lowest molten salt temperature. The device with real heat exchangers produces higher entropy generation and lower second law efficiency. Environmental water input requires more heat and entropy generation for the same steam supply. Recommendations are provided for practical designs

Data from: Stronger cooling effects of transpiration and morphology of the plants from a hot dry habitat than from a hot wet habitat

1. Leaf temperature exerts an important impact on the microenvironment and physiological processes of leaves. Plants from different habitats have different strategies to regulate leaf temperature. The relative importance of morphology and transpiration for leaf temperature regulation in the hot habitat is still unclear. 2. We investigated 22 leaf morphological traits, transpiration, and thermal properties of 38 canopy species of seedlings in a greenhouse, including 18 dominant species from a hot wet habitat (HW) and 20 dominant species from a hot dry habitat (HD). To separate the impact of transpiration and morphology on leaf temperature, we measured the diurnal courses of leaf temperatures with and without transpiration. The temperature of a reference leaf beside each individual was measured simultaneously to render temperatures comparable. 3. Generally, the species from HD showed lower leaf temperatures than the species from HW under the same conditions. Both transpiration capacity and cooling effect of leaf morphology were stronger for the plants from HD. Active transpiration provides a suitable thermal environment for photosynthesis, while xeromorphic leaves can dampen heat stress when transpiration is suppressed. Higher vein density and stomatal pore area index (SPI) facilitated higher transpiration capacity of the plants from HD. Meanwhile, shorter leaves and thinner lower epidermis of the plants from HD were more efficient in heat transfer, although relationships were much weaker than the synergic effect of all the morphologic traits. 4. Our results confirmed that transpiration and leaf morphology provided double insurance for avoiding overheating, particularly for plant from HD. We emphasize that transpiration is a more effective way to cool leaves than morphology when water is sufficient, which may be an important adaptation for plant from HD where rainfall is sporadic. Our results provide further insight into the relationship between morphology and transpiration for the regulation of leaf temperature, and the co-evolution of gas exchange and thermal regulation of leaves