A Novel Structure of High Efficiency Rotary Compressor

In recent years, various frequency compressors are developed rapidly and successfully in household air conditioner area. However, it is difficult to make advance progress on compressor performance, noise and reliability. The innovation of structure and technique are indispensable impetus to make a breakthrough. This paper presents a novel structure of high efficiency rotary compressor, which focuses on the connection mode between roller and vane of a compressor. On the one hand, the leakage gap between roller wall and vane tip is eliminated, which upgrades the capacity of compressor. On the other hand, through changing movement type of compressor parts, the mechanical state is meliorated and frictional loss is decreased. Several analysis are studied to validate the rationality of the above amelioration, which include strength and deformation simulation, frictional loss and leakage loss calculation. By comparison with conventional compressor, the performance of the novel compressor is improved obviously. In the end, the results of reliability and durability experiments reveal that they satisfy the national standard

The Finite Element Analysis of the Deflection of the Crankshaft of Rotary Compressor

The deflection of the crankshaft which transfers the power of motor to the pump of the compressor directly affects the vibration, noises and wear problems in the rotary compressor, therefore, with the requirement of higher reliability, it is important to obtain it exactly in compressor design. Various forces that the crankshaft suffers were calculated by theoretical analysis in the operation process of the compressor. And based on the finite element method (FEM), the deflection of the crankshaft was obtained by simulation in the rotary compressor. And then the measurements were performed concerning the orbit of the top dead centre of the crankshaft with non-contacting displacement sensors in the compressor. In comparison with the tests, the validity of the calculation method was verified. It was found that the results of calculation were good agreement with the tests’. In addition, several factors which affect the deflection of the crankshaft were analyzed with the FEM, and the influences of flange height, shaft diameter, mechanical air gap in the motor, rotor weight on the deflection were found distinctly, which as a primary theoretical basis is provided for the compressor design

Study on the Performance of CO2 Two-stage Rotary Compressor in Freezing and Cold Storage Conditions

This paper describes a new type CO2 two-stage rotary compressor for cold storage and freezing of food. A two-stage compression form with an upper cylinder (first-stage) and a lower cylinder (second-stage), unique oil road structures and technical parameters have been used in the rotary compressor to increase the performance. The results indicating that the optimized CO2 two-stage rotary compressor has a significant performance advantage, which the coefficient of performance (COP) increases by 4.4% ~ 6.7%

The Influence of Main Bearing Parameters on The Bearing Wear in Rotary Compressor

The main bearing and sub bearing which support the crankshaft rotation often have wear in the rotary compressor, and the exceptional wear will cause a series of problems which contain the vibration, noises, frictional power rising and reliability reduced. The process of improving the actual exceptional wear problems of bearings is analyzed. And based on the finite element method (FEM), the results of the original and improved bearings are compared with each other; contact stress is chosen to be used to evaluate the wear condition of bearings. Then the influence of height, diameter and clearance of main bearing on the wear of the bearing is analyzed by the accelerated life test and the FEM simulation, and the feasibility of the bearing contact stress to evaluate the wear condition of bearings is further verified, at the same time it provides a theoretical basis for the design of compressor bearing

Contribution of the vertical movement of dissolved organic carbon to carbon allocation in two distinct soil types under Castanopsis fargesii Franch. and C. carlesii (Hemsl.) Hayata forests

International audienceAbstractKey messageThe vertical transport of dissolved organic carbon (DOC) is an important determinant of carbon distribution across a soil profile. The transport of DOC down a soil profile can be largely influenced by incoming DOC and soil organic carbon (SOC) levels, which insulate DOC from adsorption processes regulated by soil texture and Fe/Al mineralogy.ContextUncertainties about how soil properties affect DOC transport through the soil profile require study because soils can differ strongly with respect to texture or Fe/Al mineralogy and yet retain similar quantities of DOC.AimsThis study aimed to assess the role of incoming DOC and native SOC in regulating DOC migration in soils and investigate the contribution of DOC movement to SOC allocation.MethodsWe leached a standard DOC solution extracted from Castanopsis carlesii litter through two distinct soil types, using two leaching strategies: single leaching and sequential leaching. The two soil types under a natural Castanopsis carlesii (Hemsl.) Hayata forest and a natural Castanopsis fargesii Franch. forest, respectively, differ strongly with respect to soil texture, Fe/Al oxide abundances, and SOC nature.ResultsWith single leaching, where each of six soil layers making up an entire 0–100-cm soil depth profile received single doses of standard DOC solution, deeper soil layers retained more DOC than upper soil layers, with native SOC largely masking the effects of soil texture and Fe/Al mineralogy on DOC migration. Following sequential leaching, where a sixfold larger amount of standard DOC solution sequentially percolated through the six soil layers, the upper soil layers generally retained more DOC than deeper layers. Nevertheless, in sequential leaching, desorption-induced transfer of carbon from upper soil layers to deeper soil layers resulted in greater total carbon retention than in single leaching.ConclusionForest subsoils (40–100 cm) are well below C saturation, but DOC vertical movement from top soils only transfers limited organic carbon to them. However, DOC vertical movement may greatly alter SOC allocation along the top soil profile (0–40 cm), with part of outer sphere native SOC displaced by incoming DOC and migrating downwards, which is a natural way to preserve SOC

Target-Driven Structured Transformer Planner for Vision-Language Navigation

Vision-language navigation is the task of directing an embodied agent to navigate in 3D scenes with natural language instructions. For the agent, inferring the long-term navigation target from visual-linguistic clues is crucial for reliable path planning, which, however, has rarely been studied before in literature. In this article, we propose a Target-Driven Structured Transformer Planner (TD-STP) for long-horizon goal-guided and room layout-aware navigation. Specifically, we devise an Imaginary Scene Tokenization mechanism for explicit estimation of the long-term target (even located in unexplored environments). In addition, we design a Structured Transformer Planner which elegantly incorporates the explored room layout into a neural attention architecture for structured and global planning. Experimental results demonstrate that our TD-STP substantially improves previous best methods' success rate by 2% and 5% on the test set of R2R and REVERIE benchmarks, respectively. Our code is available at https://github.com/YushengZhao/TD-STP

The first rare case of Candida palmioleophila infection reported in China and its genomic evolution in a human host environment

IntroductionCandida palmioleophila is a rare human pathogenic fungus, which has been poorly characterized at the genome level. In this study, we reported the first fatal case of C. palmioleophila infection in China and investigate the microevolution of C. palmioleophila in the human host environment.MethodsA series of C. palmioleophila stains were collected from the patient at different time points for routine microbial and drug sensitivity testing. The first C. palmioleophila isolate 07202534 was identified by de novo whole genome sequencing. The in vitro and in vivo genetic evolutionary characteristics of C. palmioleophila were discussed based on the analysis of bioinformatics data.ResultsThe six C. palmioleophila isolates displayed dose-dependent sensitivity to fluconazole. The C. palmioleophila genome contained homologous genes such as CDR1 and MDR1, which were recognized to be related to azole resistance. In addition, amino acid variation was detected at F105L and other important sites of ERG11. In addition, the mean divergence time between C. palmioleophila and Scheffersomyces stipites CBS 6054 was 406.04 million years, indicating that C. palmioleophila originated earlier than its closest relative. In addition, the six strains of C. palmioleophila isolated form the patient had higher homology and fewer mutation sites, which indicated the stability in C. palmioleophila genome. We also found that C. palmioleophila had a wide natural niche and may evolve slowly.DiscussionWe believe that this study will contribute to improve our understanding of the genetic evolution, pathogenicity, and drug resistance of C. palmioleophila and will aid in the prevention and control of its spread