Geothermal loop in-ground heat exchanger for energy extraction
AssigneeControlled Thermal Technologies Pty Ltd
InventorRodney Grahame Colwell
Life of this patent
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Abstract
A geothermal loop in-ground heat exchanger for energy extraction including an outer tubular casing and an inner tubular portion spaced from the outer tubular casing to define an injection space wherein a working fluid is injected into the injection space at a first temperature, T1 while the heat exchanger is located in a geothermal heat reservoir and the working fluid exits through the inner tubular portion at a second temperature, T2 which is greater than T1.
Claims17
A geothermal loop in-ground heat exchanger for energy extraction including:
- an outer tubular casing bounded by a horizontal lower wall and an inner tubular portion spaced from the outer tubular casing to define an intervening injection space between the outer tubular casing and the inner tubular portion;
- wherein a working fluid is injected into the injection space at a first temperature, T1, while the heat exchanger is located in a geothermal heat reservoir and the working fluid exits through the inner tubular portion at a second temperature, T2, which is greater than T1;
- a counter current heat shell is provided external to the outer tubular casing to enhance heat transfer to the working fluid;
- wherein the counter current heat shell is an annular shell, closed at an upper end by a transverse upper wall and having a lower end, the countercurrent heat shell bounded laterally by a vertical side wall;
- a reinjection port located on the vertical side wall below the transverse upper wall of the counter current heat shell;
- entry openings are spaced evenly over the length of the counter current heat shell between the lower end of the countercurrent heat shell and the reinjection port;
- and
- wherein the reinjection port allows a heat carrier to exit the counter current heat shell and the entry openings allow the heat carrier to enter the counter current heat shell.
A method of energy extraction from a geothermal heat reservoir including the steps of:
- providing a geothermal loop in-ground heat exchanger having an outer tubular casing bounded by a horizontal lower wall and an tubular portion spaced from the outer tubular casing to define an injection space;
- providing a counter current heat shell external to the outer tubular casing to enhance heat transfer to a working fluid;
- wherein:
- the counter current heat shell is an annular shell closed at an upper end by a transverse upper wall and having a lower end, and bounded laterally by a vertical side wall,
- a reinjection port located on the vertical side wall below the transverse upper wall of the counter current heat shell allowing a heat carrier to exit the counter current heat shell, and
- entry openings are spaced evenly along the counter current heat shell between the reinjection port and the lower end of the countercurrent heat shell, the entry openings allowing the heat carrier to enter the counter current heat shell;
- locating at least a portion of the heat exchanger in a geothermal heat reservoir;
- injecting a working fluid at a first temperature, T1, into the injection space;
- and
- drawing off the working fluid from the inner tubular portion at a second temperature, T2, greater than T1.
Dependencies are inferred from the claim text.