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Flow Inducer

IP.com Disclosure Number: IPCOM000240182D
Publication Date: 2015-Jan-09
Document File: 5 page(s) / 201K

Publishing Venue

The IP.com Prior Art Database

Abstract

A flow inducer is provided for gas-insulated electrical equipment, such as a gas-insulated circuit breaker or switchgear. The flow inducer is positioned inside a housing for directing the convective flow of insulating gas towards a current-carrying component of the gas-insulated electrical equipment. In a particular aspect, the flow inducer comprises a flow outlet or nozzle directed towards the current-carrying component. The flow outlet or nozzle is preferably arranged at a bottom portion of the housing volume of the gas-insulated electrical equipment and/or vertically below the current-carrying component. The current-carrying component is arranged at a distance from the housing of the electrical equipment and may by arranged at a center axis of the (e.g. cylin¬dri¬cal) housing. The current-carrying component may in particular include the puffer, the nominal contacts and/or the arcing contacts of the circuit breaker, or switching contacts of the switchgear.

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Flow Inducer

Authors: M. Dhotre, J. Korbel, and X. Ye, all of ABB Switzerland Ltd.

TECHNICAL FIELD

The present disclosure in general relates to gas-insulated electrical equipment, and specifically to gas-insulated circuit breakers or gas insulated switchgear, preferably gas-insulated high-voltage circuit breakers or gas insulated high-voltage switchgear.

BACKGROUND OF THE DISCLOSURE

A circuit breaker carries nominal current under normal condition and acts as electrical conductor. This nominal current produces ohmic heating, which causes a temperature rise in the breaker components. There exist IEC limits for the surface temperature which should not be exceeded. With increasing ratings of current, these requirements are more and more critical.

Usually, some cooling is achieved by convective flow of the gas inside the circuit breaker housing. The flow is driven by natural convection due to the heat losses from current-carrying components of the circuit breaker. The heated gas changes the density and becomes lighter. Due to gravitational effect, the heated gas flows upward from these current-carrying components towards the top of the housing and turns downward along the wall towards the bottom. However, a stagnant cold gas pool at bottom of the tank builds up, which hitherto remains unused, as shown in Figure 1.

Fig. 1

SUMMARY

According to the present disclosure, a flow inducer is provided for gas-insulated electrical equipment, such as a gas-insulated circuit breaker or switchgear. The flow inducer is positioned inside a housing for directing convective flow of insulating gas towards a current-carrying component of the gas- insulated electrical equipment. In a particular aspect, the flow inducer comprises a flow outlet or nozzle directed towards the current-carrying component. The flow outlet or nozzle is preferably arranged at a bottom portion of the housing volume of the gas-insulated electrical equipment and/or vertically below the current-carrying component. The current-carrying component is arranged at a distance from the housing of the electrical equipment and may by arranged at a center axis of the (e.g. cylindrical) housing. The current-carrying component may e.g. include the puffer, nominal contacts and/or arcing contacts of the circuit breaker, or switching contacts of the switchgear.


09.01.2015


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In a particular aspect, the flow inducer is arranged so that a space between the flow inducer and the (metal) housing of the gas-insulated electrical equipment is provided as a channel for the insulating gas. The space may be annular (which includes partially annular spaces such as spaces covering at least 30%, at least 50% or even at least 80% of an annular circumference about the axis of the housing). The channel may be provided for receiving a (convective) flow of gas from a top portion of the housing and for directing the gas to the flow outlet or nozzle.

The flow inducer can be made of any suitab...