| 摘要 |
<p>A downhole tool comprises an apparatus including an electrical member and a cooling system to maintain the electrical member within a rated temperature operating range. The cooling system includes a container holding a refrigerant. The cooling system also includes heat transfer elements for conducting refrigerant from the container in proximity to the electrical member so that a temperature adjacent the electrical member is less than ambient well bore temperature and preferably less than the maximum of the rated temperature operating range. The cooling system further includes a device for moving refrigerant from the container and through the heat transfer elements in response to pressure in the well bore. In a preferred embodiment, the refrigerant is recycled through the heat transfer circuit back to the container. A method of reducing temperature adjacent an electrical portion of a downhole tool comprises: discharging a refrigerant from a chamber in the downhole tool in response to pressure of a fluid in a well so that refrigerant flows from the chamber through an expansion valve and an evaporator; and transferring to refrigerant passing through the evaporator heat from adjacent the electrical portion of the downhole tool.</p> |
