Underground heat-exchange system

Patent metadata

Field	Value
Publication number	US-10006668-B2
Application number	US-201314913731-A
Country	US
Kind code	B2
Filing date	Nov 19, 2013
Priority date	Oct 8, 2013
Publication date	Jun 26, 2018
Grant date	Jun 26, 2018

Abstract

An underground heat exchange system is provided to reduce energy consumption for circulation of a heat transfer medium and reduce construction, management, and maintenance costs. The underground heat exchange system includes: a double-pipe heat exchanger that is buried underground to convert a heat transfer medium into a usable form; a medium collector that collects the heat transfer medium that has dispersed its heat via a heat consumption area to circulate the same to the ground heat exchanger; and a plurality of circulation loops. The medium collector includes first and second reservoirs that are arranged in two tiers: upper and lower, spaced apart from each other, an upstream pump is provided in a first circulation loop between the first and second reservoirs, and the second reservoir is placed higher than the first reservoir. The ground heat exchanger may enhance heat exchange efficiency by increasing the contact area and time between the ground and the heat transfer medium.

First claim

What is claimed is:

1. An underground heat exchange system comprising:
a double-pipe ground heat exchanger that is buried underground to convert a heat transfer medium into a form of the medium having availability of heat transfer;
a medium collector that collects the heat transfer medium that has dispersed its heat via a heat consumption area to circulate the same to the ground heat exchanger; and
a plurality of circulation loops,
wherein:
the ground heat exchanger comprises an inner pipe, an outer cylinder member that forms a double-pipe structure by the insertion and placement of the inner pipe, and a blocking cover that closes off an opening of the outer cylinder member,
the medium collector comprises a first reservoir and a second reservoir that are arranged in two tiers which are upper and lower reservoirs that are spaced apart from each other,
an upstream pump is provided in a first circulation loop between the first reservoir and second reservoir, and the second reservoir is placed higher than the first reservoir,
an on-off valve is provided in a second circulation loop between the second reservoir and the ground heat exchanger to adjust a water level or a pressure of the second reservoir by means of the upstream pump,
a water level sensor is provided at the second reservoir,
a controller is provided among the upstream pump, the on-off valve, and the water level sensor to allow the upstream pump, the on-off valve, and the water level sensor to work in conjunction with one another,
an intermediate reservoir capable of storing the heat transfer medium converted by the ground heat exchanger is provided in a third circulation loop arranged between the ground heat exchanger and the heat consumption area,
the inner pipe is connected to one end of the second circulation loop running from the second reservoir,
the outer cylinder member is open at one end and closed at the other to enable the heat transfer medium flowing along an outer surface of the inner pipe to exchange a heat with a ground,
the blocking cover comprises a through hole for inserting the inner pipe and an extraction port for connecting to the third circulation loop leading to the heat consumption area, and
a flow rate reducing means for reducing a flow rate of the heat transfer medium is provided either on the outer surface of the inner pipe inserted into the outer cylinder member or on an inner periphery of the outer cylinder member, the flow rate reducing means being in a form of helical guide flanges or screw threads and further comprising collision members for creating a vortex in the heat transfer medium.

2. The underground heat exchange system of claim 1 , wherein a height difference between the first reservoir and the second reservoir is determined based on a depth of the ground heat exchanger and a heat transfer rate.

3. The underground heat exchange system of claim 1 , wherein the intermediate reservoir is placed higher than the first reservoir and lower than the second reservoir.

4. The underground heat exchange system of claim 1 , wherein an extraction pump is further provided in the third circulation loop between the intermediate reservoir and the ground heat exchanger to extract the heat transfer medium from the ground heat exchanger.

5. The underground heat exchange system of claim 1 , wherein the blocking cover further comprises: a fastening recess corresponding to the extremity of the opening of the outer cylinder member; and seals formed on every contact surface of the through hole to ensure water-tightness and air-tightness.

6. The underground heat exchange system of claim 1 , wherein a fixing blade is further provided on the outer surface of the inner pipe so as to be held in place by being screwed onto a flange surface of the through hole of the blocking cover.

7. The underground heat exchange system of claim 1 , wherein the collision members are protrusions or irregular bumps formed on the bottom or wall surface.

8. The underground heat exchange system of claim 1 , wherein the outer cylinder member is divided into a blocking area where blocks the heat transfer between the heat transfer medium and the ground, and an active area where facilitates the heat transfer between the heat transfer medium and the ground, depending on a depth to which the whole body is buried underground, and the blocking area and the active area are made of different materials having different thermal conductivity.

9. The underground heat exchange system of claim 8 , wherein the blocking area of the outer cylinder member is 5 to 6 m deep from the opening.

10. The underground heat exchange system of claim 9 , wherein the outer cylinder member is configured in such a way so as to wrap the outer surface of the blocking area with an insulation member.

Assignees

• Univ Seoul Ind Coop Found

Inventors

• Yu Byung Deok
• Min Hyunsoo
• Jeon Junjin

Classifications

• F24T2010/50

  Component parts, details or accessories · CPC title

• Y02E10/125

  Cross-Sectional Technologies · mapped topic

• F28F2215/10

  Secondary fins, e.g. projections or recesses on main fins · CPC title

• F24T10/10 Primary

  with circulation of working fluids through underground channels, the working fluids not coming into direct contact with the ground · CPC title

• F24T2010/56

  Control arrangements · CPC title