Adiabatic heat pump with adaptive control
OwnerJoseph L. Cicconeinventor
Life of this patent
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Abstract
A heat transfer apparatus transfers heat from a heat source to a heat sink. The apparatus comprises a compressor-expander and a reservoir that are connected by two separate fluidic loops for the respective circulation principally of vapor and liquid portions of a working fluid. The loops may each contain a heat exchanger through which heat is respectively absorbed and rejected. The apparatus may further comprise temperature sensors responsive to the temperature of the working fluid at certain locations within the apparatus and an electronic control device configured to adaptively control the operation to improve stability and efficiency.
Claims40
A heat transfer apparatus, comprising:
- (a) a compressor-expander having a cylindrical bore and a piston movable within the bore along a central axis thereof, the piston hermetically separating the bore into first and second volume portions that are fluidically connected through an intervening check valve that is configured to permit transfer of a working fluid from the first volume portion to the second volume portion;
- and wherein the cylindrical bore has:
- a liquid compressor inlet and a liquid compressor outlet situated respectively to receive working fluid into, and discharge working fluid out of, the first volume portion;
- and a vapor compressor outlet situated to discharge working fluid from the second volume portion;
- (b) a prime mover capable of being connected to an external power source and configured to drive the piston in reciprocating motion along the central axis;
- (c) a reservoir having a vapor return inlet, a liquid return inlet, and a liquid reservoir outlet that is in fluidic communication with the liquid compressor inlet through an intervening supply valve;
- (d) a vapor return providing fluidic communication between the vapor compressor outlet and the vapor return inlet controllable by an intervening regulating valve;
- and
- (e) a liquid return providing fluidic communication between the compressor-expander and the reservoir controllable by an intervening return valve.
A method for transferring heat energy from a heat source to a heat sink, comprising:
- providing a reservoir containing subcooled working fluid, a compressor-expander having a total volume variably apportioned between first and second volume portions, a vapor return, and a liquid return, wherein the first volume portion is fluidically connected to the reservoir through the liquid return and the second volume portion is fluidically connected to the reservoir through the vapor return, and carrying out repetitively a cycle comprising the steps of:
- (a) transferring a preselected amount of the subcooled working fluid from the reservoir to the first volume portion;
- (b) expanding the first volume portion to reduce adiabatically the pressure therein, whereby the working fluid is cooled and at least a portion thereof is converted to vapor;
- (c) contracting the second volume portion to increase adiabatically the pressure therein above a target pressure setpoint, whereby any working fluid therein is heated, and thereafter releasing the pressurized fluid to pass through the vapor return to the reservoir, whereby heat is rejected from the working fluid through the vapor return to the heat sink and pressure in the second volume portion is reduced below the target pressure setpoint;
- (d) thereafter, expanding the second volume portion and contracting the first volume portion;
- (e) equalizing the pressures of the working fluid between the first and second volume portions by fluidically connecting the first and second volume portions, so that the temperature of working fluid remaining in the second volume portion is increased;
- and
- (f) thereafter, emptying the first volume portion by isobarically transferring the working fluid remaining therein through the liquid return to the reservoir, while removing ambient heat into the working fluid in the liquid return.
Dependencies are inferred from the claim text.