The Ohio State University

Gas Research Institute

Columbia Gas System Service Corporation

Columbia Gas of Ohio, Inc.

Richard N Christensen

F Bert Cook

Stephen E Petty

Howard C Meacham, Jr

Kevin R McGahey

Anthony C DeVuono

Srinivas Garimella

Paul E George, Ii

Sherwood G Talbert

William H Wilkinson

D Karl Landstrom

Michael Garrabrant

Yong Tae Kang

Jiming Cao

Michael A Garrabrant

Roger F Stout

E Thomas Henkel

Yong-Tae Kang

A heat engine () achieves operational efficiencies by: 1) recovering waste heat from heat engine expander () to preheat heat-engine working fluid, 2) using super-heated working fluid from compressor () to pre-heat heat-engine working fluid, and 3) using reject heat from condenser () and absorber () to heat the heat-engine boiler (). A dual heat-exchange generator () affords continuous operation by using gas-fired heat exchanger () to heat generator () when intermittent heat source (), e.g., solar, is incapable of heating generator (). The combination of heat engine () and absorption and compression heat transfer devices () allows use of low-temperature heat sources such as solar, bio-mass, and waste heat to provide refrigeration, heating, work output including pumping and heating of subterranean water and electrical generation.

Heat engine

Mass and heat transfer devices and methods of use

A fluid heat exchange apparatus is disclosed that can be used as an absorber in an absorption cooling system. The compact absorber design uses an accordion fin assembly to direct solution downward through the absorber on a plurality of alternatively angled fins. The alternatively angled fins cause the solution to collect at each level against a thermally conductive surface. Each fin includes a plurality of house-shaped perforations that allow the solution to spill over onto the next level fin. The house-shaped perforations also allow the vapor to flow upward in effective counterflow with the solution.

Perforated fin heat and mass transfer device

Apparatus for mass transfer of gas and liquid flowing through passages therein has a vertical enclosure formed in a pair of sheet metal plates sealed together around their periphery and formed to have rows of horizontal passages communicating with columns of vertical passages in and adjacent to a vertical plane defined by flat contiguous areas of the plates between and around the passages. The inner surfaces of the passages have highly wettable areas to substantially maximize transfer of mass and heat. Each horizontal passage is continuous between the vertical passages with which it communicates. In the main portion of the apparatus, the axis of each vertical passage between one horizontal passage and the next lower one passes through the middle of a flat contiguous area between that next lower horizontal passage and the following still lower one and midway between the axes of the two vertical passages on each side of that flat area, so that fluid in the vertical passages divides approximately equally in its vertical flow between each horizontal passage and the next. Vertical passages connecting alternate ends of successive horizontal passages may be added, to provide also a serpentine path for fluid therein. Openings are provided to receive and expel, respectively, fluids that are to be, or have been, absorbed or desorbed. A plurality of the apparatuses may be placed in another enclosure for transfer of heat between them and a fluid flowing through the enclosure or for mass transfer with such fluid.

Enhanced fluid-liquid contact

A capillary twisted fluted tube is formed with an interior helical capillary flute and associated interior helical crest and a complementary exterior helical crest and flute, respectively. Liquid rises in the interior capillary flute and is expelled at or near the top of the tube in fine droplets that promote mass transfer efficiencies as a result of improved vapor-equilibrium. A capillary fluted tube placed in a helical groove of a heat insulating material to expose only one side of the tube to hot combustion products promotes increased capillary rise on one side of the tube with increased expulsion and spatter of liquid from the capillary channel. Exterior tube heat transfer is enhanced by enclosing the tube in a second tube or forming the tube into a winding and enclosing the winding in a cylinder. Contact of the exterior tube crests with the enclosing tube or cylinder improves heat transfer efficiencies as a result of confined flow of heat transfer fluid within the enclosing tube or cylinder. The capillary tube can have multiple sections with separate enclosing tubes and cylinders to take advantage of different heat transfer fluids or direct process-to-process heat exchange for each section.

Capillary fluted tube mass and heat transfer devices and methods of use

An absorption refrigeration machine with two, non-fluid linked loops uses heat from a first loop rectifier to heat a second loop generator by either direct or hydronic heat exchange. Flue gas from the heating of the first loop generator is used to heat strong solution in the second loop. Heat from the first loop condenser and absorber are also used to heat the second loop generator by either direct or hydronic fluid coupling. In order to improve further the efficiencies of the absorption machine, a mass and heat transfer device is used that provides a liquid and vapor distribution system that affords effective heat transfer in conjunction with a large and continually renewed liquid surface area and a relatively constant vapor velocity to effect efficient mass transfer among the various components and processes of the refrigeration machine. A simple liquid metering system is used to meter equal amounts of liquid into the divided liquid flow arrangements used in various components of the machine.

Heat pump

An absorption refrigeration and heating system has helical concentric coils for two generators (80 and 81) and recuperators (86 and 95) on a common axis (232) with a heating unit (84) at the center and allowing the hot combustion gases (245) to circulate in serpentine fashion through separate concentric chambers containing the coils. An absorber (97), condenser (100) and recuperator (107) are placed in a single module (270) and configured with a tube-in-tube or tube-in-cylinder construction with fluted inner tubes. A general purpose, divided-flow, tube-in-cylinder, heat-transfer device (400) is used to reduce the pressure drop in the circulating fluid.

Generator for absorption heat pumps

A refrigeration and heating system in which an absorber (97), condenser (100) and recuperator are placed (107) in a single module (270) and are provided with tube-in-tube or tube-in-cylinder construction with fluted inner tubes. A general purpose, divided-flow, tube-in-cylinder, heat transfer device (400) is used to reduce the pressure drop in the circulating fluid.

Heat transfer apparatus for heat pumps

A refrigeration and heating system has been made in which improved efficiencies are obtained by placing helical concentric coils of at least two generators (80 and 81) and recuperators (86 and 95) on a common axis (232) with a heating unit (84) at the center and allowing the hot combustion gases (245) to circulate in serpentine fashion through separate concentric chambers containing the coils. Further efficiencies are obtained by placing an absorber (97), condenser (100) and recuperator (107) in a single module (270) and by using tube-in-tube or tube-in-cylinder construction with fluted inner tubes. A general purpose, divided-flow, tube-in-cylinder, heat-transfer device (400) is used to reduce the pressure drop in the circulating fluid.

Heat transfer apparatus

A direct contact condensing heat-exchanger is provided with a water heat transfer medium in which combustion product gases are dispersed in finely divided bubble form against a relatively low hydrostatic pressure differential for efficient sensible heat and latent heat recovery purposes. In one actual application, a warm-air furnace system having a burner that produces combustion product gases as a heat source is provided with the novel direct contact condensing heat-exchanger as a seondary heat-exchanger that advantageously recovers both sensible heat and latent heat from the combustion product gases.

Dispersed bubble condensation

A refrigeration and heating system has been made in which improved efficiencies are obtained by placing helical concentric coils of at least two generators and recuperators on a common axis with a heating unit at the center and allowing the hot combustion gases to circulate in serpentine fashion through separate concentric chambers containing the coils. Further efficiencies are obtained by placing an absorber, condenser and recuperator with a single module and by using tube-in-tube or tube-in-cylinder construction with fluted inner tubes.

A absorption refrigeration system having cooling and heating modes of operation functions with a double-effect or 'split' refrigeration cycle having approximately the same refrigerant concentration span in each cycle loop. The system includes a novel direct expansion combined evaporator and absorber assembly with improved heat transfer characteristics and with interchangeable liquid flows accomplished through actuation of a conventional reversing valve. Also, the system is provided with improved recuperative heat exchangers to further increase system energy conversion efficiencies.

Growing community of inventors

Columbus, OH, United States of America

Richard N Christensen