Serpentine heat pipe and dehumidification application in air conditioning systems

• US 5,845,702 A
• Filed: 06/30/1992
• Issued: 12/08/1998
• Est. Priority Date: 06/30/1992
• Status: Expired due to Term

• Current Assignee: Heat Pipe Technology, Inc. (Berkshire Hathaway Incorporated)
• Original Assignee: Heat Pipe Technology, Inc. (Berkshire Hathaway Incorporated)
• Inventors: Dinh, Khanh
• Primary Examiner(s): Leo, Leonard R.
• Application Number:
  US07/906,360
• Time in Patent Office: 2,352 Days
• Field of Search: 165/104.14, 165/150, 165/104.21, 165/104.22, 165/104.29, 165/104.28, 62/119
• US Class Current: 165/104.21
• CPC Class Codes: F24F 3/1405 in which the humidity of the air is exclusively affected by contact with the evaporator of a closed-circuit cooling system or heat pump circuit
• CPC Class Codes: F28D 15/0266 with separate evaporating and condensing chambers connected by at least one conduit; Loop-type heat pipes; with multiple or common evaporating or condensing chambers F28D15/043 takes precedence

Abstract

A heat pipe heat exchanger is provided in the form of a serpentine heat pipe that does not have the ends of the individual tubes manifolded to one another via a straight pipe or via any other common connector. Instead, it has been discovered that heat pipes connected via U-bends to form a continuous coil function adequately. The serpentine heat pipe may include integral condenser and evaporator portions separated by a divider to form a one-slab heat exchanger, or separate evaporator and condenser coils connected to one another by vapor and return lines to form a two-section heat pipe. A method of producing a serpentine heat pipe includes providing a plurality of U-shaped tubes which are interconnected to form a single serpentine heat pipe, one of the tubes having an open end, and inserting sufficient refrigerant in the one tube to allow each of the tubes to function as a separate heat pipe. The serpentine heat pipe heat exchanger may be used to increase the dehumidification capacity of an air conditioner.

Claims

1. A method of dehumidifying air comprising the steps of:

pre-cooling and dehumidifying air by passing air through an evaporator section of a device comprising first and second serpentine heat pipe sections configured as continuous coils, a vapor line and a liquid return line connecting the first and second serpentine heat pipe sections to form a single continuous coil two-section heat pipe having a generally U-shaped configuration with the first and second serpentine heat pipe sections on respective sides of the U-shape, the first and second serpentine heat pipe sections each including a plurality of U-shaped tubes, the plurality of U-shaped tubes of the first serpentine heat pipe section having a first plane passing therethrough which is substantially parallel to a second plane which passes through the plurality of U-shaped tubes of the second serpentine heat pipe section, a height of the second serpentine heat pipe section being approximately equal to a height of the first serpentine heat pipe section, the height of the first serpentine heat pipe section being defined by a distance between two edge tubes of the first serpentine heat pipe section and the height of the second serpentine heat pipe section being defined by a distance between two edge tubes of the second serpentine heat pipe section, the first and second serpentine heat pipe sections and a cooling coil being horizontally aligned in side-by-side-by-side fashion with the cooling coil being disposed in between the first and second serpentine heat pipe sections, the single continuous coil two-section heat pipe being partially filled with a refrigerant which passively circulates through the single continuous coil two-section heat pipe in a continuous cycle and in a self-pumping manner without the aid of a separate pump, the first serpentine heat pipe section forming the evaporator section of the two-section heat pipe and the second serpentine heat pipe section forming a condenser section of said two-section heat pipe;

then

cooling said air via the cooling coil; and

then

reheating said air via the condenser section of said device.

2. An apparatus comprising:

a cooling coil, and

a single continuous coil two-section heat pipe having a generally U-shaped configuration, said single continuous coil two-section heat pipe including

first and second serpentine heat pipe sections each configured as a continuous coil, and

a vapor line and a liquid return line which connect said first serpentine heat pipe section to said second serpentine heat pipe section thereby forming said single continuous coil two-section heat pipe with said generally U-shaped configuration with said first serpentine heat pipe section and said second serpentine heat pipe section on respective sides of said U-shape,

wherein said first and second serpentine heat pipe sections each include a plurality of U-shaped tubes,

wherein said single continuous coil two-section heat pipe is partially filled with a refrigerant which passively circulates through the single continuous coil two-section heat pipe in a self-pumping manner and without the aid of a separate pump, and said first serpentine heat pipe section forms an evaporator section of said two-section heat pipe and said second serpentine heat pipe section forms a condenser section of the two-section heat pipe,

wherein said first and second serpentine heat pipe sections, said vapor line, and said liquid return line are constructed and arranged such that, in operation, said first and second serpentine heat pipe sections and said cooling coil are horizontally aligned in side-by-side-by-side fashion with said cooling coil being disposed in between said first and second serpentine heat pipe sections.

3. The device according to claim 2, further comprising at least one two-section serpentine heat pipe stacked on top of said two-section heat pipe, and heat conducting fins interconnecting said two-section heat pipes to form a heat pipe heat exchanger.

4. The device according to claim 2, further comprising an air conditioner having said cooling coil as a primary evaporator, and wherein said evaporator section of said two-section heat pipe is located upstream of said primary evaporator and said condenser section of said two-section heat pipe is located downstream of said primary evaporator.

5. A device according to claim 2, further comprising heat conducting fins which interconnect the plurality of U-shaped tubes of at least one of the first and second serpentine heat pipe sections.

6. A device according to claim 2, wherein said vapor line and said liquid return line are parallel.

7. A device for improving the dehumidification capability of an air conditioner, comprising:

a primary evaporator having a base, a side surface substantially perpendicular to said base, and an operative surface substantially perpendicular to said base, said base having a bottom surface parallel to a ground plane;

a single continuous coil U-shaped two-section heat pipe heat exchanger including

a refrigerant which passively circulates through said U-shaped two-section heat pipe heat exchanger in a continuous cycle and in a self-pumping manner without the aid of a separate pump,

a first serpentine section disposed opposing a first side of said operative surface and arranged substantially parallel therewith, said first serpentine section forming an evaporator section of said U-shaped two-section heat pipe heat exchanger,

a second serpentine section disposed opposing a second side of said operative surface and arranged substantially parallel therewith, said second serpentine heat pipe section forming a condenser section of said U-shaped two-section heat pipe heat exchanger,

a vapor line connecting said first serpentine section to said second serpentine section, said vapor line located adjacent said side surface, said vapor line being parallel to a bottom surface of said base, and said vapor line having a linear section with a length less than a height of said at least one side surface, and

a liquid return line connecting said first serpentine section to said second serpentine section, said liquid return line located adjacent said side surface, said vapor line and said liquid return line being parallel to a bottom surface of said base, and said liquid return line having a linear section with a length less than said height of said at least one side surface; and

a housing surrounding said primary evaporator and said U-shaped two-section heat pipe heat exchanger so that said refrigerant cycles passively between said evaporator section and said condenser section when an air stream passes through said housing;

wherein said first and second serpentine heat pipe sections each include a plurality of U-shaped tubes,

wherein a first plane which passes through said plurality of U-shaped tubes of said first serpentine heat pipe section is parallel to a second plane which passes through said plurality of U-shaped tubes of said second serpentine heat pipe section,

wherein a height of said second serpentine heat pipe section is approximately equal to a height of said first serpentine heat pipe section, said height of said first serpentine heat pipe section being defined by a distance between two edge tubes of said first serpentine heat pipe section and said height of said second serpentine heat pipe section being defined by a distance between two edge tubes of said second serpentine heat pipe section,

wherein said primary evaporator is disposed between said first serpentine section and said second serpentine section.