Single-screw expander screw channel exhaust residual speed utilization system

Abstract

The invention discloses a utilization system for exhaust leaving velocity of spiral grooves of a single-screw expansion machine, and belongs to the field of power machinery. The utilization system for exhaust leaving velocity of the spiral grooves of the single-screw expansion machine comprises a screw of the single-screw expansion machine, star wheels matched with the screw, a machine shell outside the screw and a main shaft connected with the screw, and is characterized in that exhaust holes which communicate with outlets of the spiral grooves are formed in outlet ends of the spiral grooves at the tail part of the screw; during the operation process, the exhaust holes communicate with the exterior through holes formed in the end face of the machine shell; each spiral groove corresponds to one exhaust hole; and the exhaust holes are the only channel for exhausting gases inside the spiral grooves. According to the utilization system, the underexpansion loss of the single-screw expansion machine under the working condition of a large expansion ratio is reduced, specifically, when the practical expansion ratio is larger than the optimal expansion ratio, the efficiency of the expansion machine is not reduced or the reduction speed is relatively low while the expansion ratio increases.

Description

technical field [0001] The invention relates to a novel single-screw expander screw channel exhaust residual speed utilization system, which aims at reducing the under-expansion loss of the single-screw expander and belongs to the field of power machinery. Background technique [0002] There are two types of common expanders, namely velocity type and volume type. The working principle of the speed type is to facilitate the high-speed airflow generated by the nozzle to drive the impeller to rotate, while the volumetric expander uses the volume change produced by some structures to work. Velocity expanders are usually used in large-scale (MW-level) power output systems, while volumetric expanders are generally used in smaller-scale (below 1MW) power output systems. [0003] Positive displacement expanders mainly include piston type, scroll type, single-screw type and twin-screw type, etc. Among them, single-screw expander is a structural type with obvious advantages. The main...

AI Technical Summary

Problems solved by technology

Over-expansion means that when the expansion process ends, the gas in the screw channel has expanded to a pressure lower than the exhaust pressure. At this time, the gas in the exhaust pipe quickly flows back to the screw channel through the exhaust hole, which increases the gas pressure in the screw channel. , consumes part of the expansion work, and at the same time increases the exhaust push work of the expander, resulting in over-expansion loss

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