US 3,986,354 A · Method and apparatus for recovering low-temperature industrial and solar waste heat energy previously dissipated to ambient

Abstract

A method and apparatus are described for recovering useful amounts of low-temperature industrial and solar waste heat energy previously dissipated to ambient. The low-temperature heat energy is used cyclically for heating and expanding thermally expandable wall means shown as a cylindrical walled structure located between two pumping chambers for simultaneously changing the volumes of the chambers in opposite senses, then a cold sink is used cyclically for cooling and contracting said cylindrical walled structure for again simultaneously changing the volumes of both chambers in the opposite senses, i.e. in push-pull relationships. The cyclic change in volumes of the chambers displaces an incompressible fluid which is used for pumping a liquid from a reservoir for performing useful work, and, in one form of the invention, the liquid is directed into an accumulator under pressure, and the pressurized liquid in the accumulator may thereafter be utilized to perform useful work. A heat transfer fluid medium is used in one portion of the cycle to transfer heat energy from the energy source to heat and expand the cylindrical walled structure, and in another portion of the cycle to absorb heat energy from this walled structure to cool and contract it. This heat transfer fluid medium is shown as being compartmentalized into a number of small insulated volumes thereof which progressively serve to heat and cool the expandable wall means of the pumping chambers while minimizing loss of heat energy. For minimizing thermal losses, hydraulic transformers may be included isolating the incompressible fluid (being pulsated by the pumping chambers) from the pressurized liquid. This incompressible pulsating fluid may be a de-gassed liquid or a soft elastomer.

Claims30

Dependent claims

The method for recovering waste industrial or solar heat energy for performing mechanical work comprising the steps of:

defining first and second pump chambers,
forming between said chambers a thermally expandable walled structure from strong material having good heat conductivity and a relatively low specific heat and which expands when heated in the temperature range of operation,
filling both said chambers with incompressible fluid,
heating a fluid heat transfer medium by said heat energy,
passing the heat medium in heat exchange relationship with said walled structure for heating and expanding said walled structure in push-pull relationship between said chambers for increasing the volume of said first chamber while simultaneously decreasing the volume of said second chamber, thereby displacing said incompressible fluid into said first chamber and out of said second chamber,
passing a fluid heat transfer medium in heat transfer relationship with said cold sink for cooling the medium,
passing the cooled medium in heat exchange relationship with said walled structure for cooling and contracting said walled structure in pull-push relationship between said chambers for decreasing the volume of said first chamber while simultaneously increasing the volume of said second chamber, thereby displacing said incompressible fluid out of said first chamber and into said second chamber,
repeating said steps for cyclically displacing the incompressible fluid into and out of said first and second chambers, and
utililzing the cyclic displacement of said incompressible fluid for pumping a liquid for performing useful mechanical work.

6 more elements

The method for recovering waste industrial or solar heat energy in a form useful for performing mechanical work comprising the steps of:

providing a reservoir for holding a liquid to be pumped,
providing an accumulator for holding said liquid under pressure,
defining a pump chamber,
forming a thermally expandable cylindrical wall of said chamber from strong material having good heat conductivity and a relatively low specific heat and which expands when heated in the temperature range of operation,
filling said chamber with incompressible fluid,
providing displacement communication between said liquid and said incompressible fluid through a first check valve for permitting said first liquid to flow from said reservoir toward said pumping chamber while preventing reverse flow back into said reservoir,
providing displacement communication between said incompressible fluid and said accumulator through a second check valve for permitting said first liquid to be pumped through said second check valve into said accumulator while preventing reverse flow back from said accumulator,
providing a cold sink,
utilizing said heat energy to heat a fluid heat transfer medium,
passing said heat transfer medium in heat exchange relationship with said cylindrical wall for heating it, thereby to expand said cylindrical wall for changing the volume of said pump chamber in one sense for displacing said incompressible fluid in one direction,
passing said heat transfer medium in heat exchange relationship with said cold sink for cooling said medium,
passing the cooled medium in heat exchange relationship with said cylindrical wall for cooling it, thereby to contact said cylindrical wall for changing the volume of said chamber in the opposite sense for displacing said incompressible fluid in the opposite direction,
utilizing said displacements of said incompressible
fluid for pumping said liquid for withdrawing said liquid from said reservoir and for pumping said liquid into said accumulator under pressure, and
utilizing the pressurized liquid in said accumulator as stored energy useful for performing mechanical work.

12 more elements

A thermally-actuated expansion/contraction pump comprising:

an inner hollow cylindrical member,
barrier means plugging said member at two spaced locations for forming a pair of inlet-outlet ducts in the opposite ends of said hollow member,
cylindrical wall means of thermally expandable material surrounding said hollow member,
a pair of end caps encircling said ducts and secured to opposite ends of said cylindrical wall means,
said cylindrical wall means and said end caps defining an inner pumping chamber,
one of said caps being secured to one of said inlet-outlet ducts.
the other end cap engaging in sliding relationship with the other inlet-outlet duct,
said cylindrical wall means having a plurality of passages extending axially therethrough and said end caps having passages therein providing communication between the passages in said cylindrical wall means and the respective inlet-outlet ducts for enabling a fluid heat transfer medium to be circulated and then back-circulated through the passages in said cylindrical wall means,
a rigid housing surrounding said cylindrical wall means and said end caps and being secured to both of said inlet-outlet ducts,
said rigid housing defining an outer pumping chamber located therein and which extends around said cylindrical wall means and said end caps,
insulation material positioned around said housing, and
a pair of couduits extending from the exterior of said pump into said inner and outer pumping chambers.

9 more elements

A system for recovering industrial or solar heat energy comprising:

a first heat exchanger for absorbing the heat energy to be recovered adapted to have a fluid heat exchange medium passed therethrough,
a second heat exchanger for rejecting unused heat energy into a cold sink adapted to have the fluid heat exchange medium passed therethrough,
a belt of compressible thermally insulating material having a plurality of compartments therein for carrying a volume of said medium in each compartment thermally insulated from the volumes thereof in other compartments,
first, second, third and fourth pairs of squeeze rollers each pair being arranged for the belt to pass therebetween for squeezing and releasing sequential portions of the compressible insulating material for squeezing and releasing sequences of said compartments,
said first pair of squeeze rollers being operatively associated with said first heat exchanger for causing the volumes of the fluid heat exchange medium to be expressed from compartments of the belt to pass through said first heat exchanger and to re-enter the released compartments as a freshly heated medium,
first control means for moving said first pair of squeeze rollers apart into an inactive position,
said second pair of squeeze rollers being operatively associated with said second heat exchanger for causing volumes of the medium to be expressed from compartments of the belt to pass through said second heat exchanger and to re-enter the released compartments as a freshly cooled medium,
a pump having thermally actuatable expansion/contraction wall means positioned in push-pull relationship between a pair of pumping chambers for changing the volumes of said chambers in opposite senses upon expansion and contraction of said wall means,
said third and fourth pair of squeeze rollers being operatively associated with said pump for causing volumes of the medium to be expressed from compartments of the pump to pass in heat exchange relationship with said expansion/contraction wall means and to re-enter the released compartments,
second control means for moving said second pair of squeeze rollers apart into an inactive position, and
means for moving said belt back and forth between said four pairs of squeeze rollers.

8 more elements

Dependencies are inferred from the claim text.

Method and apparatus for recovering low-temperature industrial and solar waste heat energy previously dissipated to ambient

Life of this patent

Method and apparatus for recovering low-temperature industrial and solar waste heat energy previously dissipated to ambient

Life of this patent

Abstract

Claims30