Inscrição na biblioteca: Guest

ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

HEAT TRANSFER AND FLOW CHARACTERISTICS OF ULTRA-MICRO STEAM INJECTOR AND ITS OPERATING CONDITION

Get access (open in a dialog) DOI: 10.1615/IHTC16.cod.023163
pages 2219-2225

Resumo

A steam injector (SI) has capability to be applied to heat pump systems and be down sized them. A SI works as a passive jet pump without external power sources. Moreover, it has high heat-transfer performance due to direct contact condensation between steam flow and subcooled water jet. The objective of the present study is to clarify heat transfer and flow characteristics of an ultra-micro steam injector (UMSI) to develop a small SI. To the goal of the future SI, SIs with throat diameters of 1000 µm and 600 µm were designed and these were investigated experimentally. In the present study, internal flow was visualized by a high-speed video camera. Simultaneously, pressure and temperature were measured synchronized with the high-speed visualization. The main parameters were inlet steam pressure, inlet water mass flow rate, inlet water temperature, inlet cross-section ratio between a water nozzle and a steam nozzle, and diameter of a diffuser exit. As a result, the formation of the water jet and characteristics during operation were confirmed in UMSI. It was verified that discharged pressure became higher than the inlet pressure. In addition, the ratio between discharged pressure and inlet steam pressure was increased by changing the diffuser exit diameter with throat diameter of 1000 µm.