US2026036348A1PendingUtilityA1
Adiabatic heat pump with adaptive control
Individually held — no corporate assignee on recordPriority: Jul 31, 2024Filed: Jan 24, 2025Published: Feb 5, 2026
Est. expiryJul 31, 2044(~18 yrs left)· nominal 20-yr term from priority
Inventors:CICCONE JOSEPH L
F25B 30/02F25B 13/00F25B 1/02F25B 45/00
65
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Claims
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.
Claims
exact text as granted — not AI-modifiedWhat is claimed is:
1 . 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.
2 . The heat transfer apparatus of claim 1 , wherein the liquid return comprises a liquid heat exchanger having a liquid heat exchanger inlet, and a liquid heat exchanger outlet, wherein the liquid heat exchanger inlet is in fluidic communication with the liquid compressor outlet and the liquid heat exchanger outlet is in fluidic communication with the liquid return inlet.
3 . The heat transfer apparatus of claim 2 , wherein the return valve is interposed between the liquid compressor outlet and the liquid heat exchanger inlet.
4 . The heat transfer apparatus of claim 2 , wherein the return valve is interposed between the liquid heat exchanger outlet and the liquid return inlet.
5 . The heat transfer apparatus of claim 1 , wherein the vapor return comprises a vapor heat exchanger having a vapor heat exchanger inlet in fluidic communication with a vapor heat exchanger outlet, and wherein the vapor heat exchanger inlet is in fluidic communication with the vapor compressor outlet and the vapor heat exchanger outlet is in fluidic communication with the vapor reservoir inlet.
6 . The heat transfer apparatus of claim 5 , wherein the regulating valve is interposed between the vapor heat exchanger outlet and the vapor reservoir inlet.
7 . The heat transfer apparatus of claim 1 , wherein the prime mover actuates the piston through a rotating crank and connecting rod.
8 . The heat transfer apparatus of claim 7 , further comprising a flywheel associated with the rotating crank.
9 . The heat transfer apparatus of claim 1 , wherein the vapor return inlet and the liquid return inlet are fluidically connected external to the reservoir to form a single reservoir inlet thereto.
10 . The heat transfer apparatus of claim 1 , wherein the check valve is integral with the piston.
11 . The heat transfer apparatus of claim 1 , wherein the compressor-expander further comprises a bypass tube that fluidically connects the first and second volume portions, and the check valve is situated in the bypass tube to control fluid flow therethrough.
12 . The heat transfer apparatus of claim 1 , further comprising an electronic control device and wherein at least one of the check valve, the supply valve, the regulating valve, and the return valve is configured to be electrically actuatable by the electronic control device.
13 . The heat transfer apparatus of claim 12 , further comprising a sensor configured to provide to the electronic control device a signal indicative of the position of the piston within its reciprocal motion.
14 . The heat transfer apparatus of claim 12 , further comprising at least one temperature sensor configured to provide to the electronic control device a signal indicative of the temperature of the working fluid at a preselected location within the heat transfer apparatus.
15 . The heat transfer apparatus of claim 14 , wherein the at least one temperature sensor is configured to indicate the temperature of the working fluid at one or both of the reservoir and the liquid compressor outlet.
16 . The heat transfer apparatus of claim 1 , wherein the reservoir is configured to permit working fluid therein to be subjected to a preselected overpressure.
17 . The heat transfer apparatus of claim 1 , wherein the electrical power source comprises an electrical storage device adapted to store energy returned by the prime mover during a portion of the reciprocating motion of the piston.
18 . 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.
19 . The method of claim 18 , wherein at least part of steps (b) and (c) are carried out concurrently.
20 . The method of claim 18 , wherein the first and second volume portions are delimited by a piston movable within the compressor-expander.
21 . The method of claim 20 , wherein the piston is moved by a prime mover energized by an external power source.
22 . The method of claim 20 , wherein the expanding, contracting, and emptying of steps (a) through (f) are carried out by moving a piston within the compressor-expander.
23 . The method of claim 22 , wherein, in step (d), energy stored in the working fluid within the second volume portion is converted to work that drives the piston.
24 . The method of claim 18 , wherein the emptying of step (f) comprises passing the working fluid from the first volume portion through a liquid heat exchanger to the reservoir.
25 . The method of claim 21 , wherein, during at least a portion of each cycle, energy derived from the working fluid is converted to mechanical work that impels the motion of the piston.
26 . The method of claim 25 , wherein, during at least a portion of each cycle, the motion of the piston causes the prime mover to generate electrical energy that is returned to the external energy source.
27 . The method of claim 18 , wherein the preselected amount of subcooled working fluid is adaptively adjusted during at least some of the cycles to urge a measured control temperature to reach a final control temperature setpoint, the control temperature being the cold side temperature or the reservoir temperature.
28 . The method of claim 27 , wherein the adaptive adjustment comprises changing the preselected amount of subcooled working fluid in accordance with the formulas:
Δ
T
control
=
Target
T
control
-
Measured
T
control
Updated
Volume
=
Current
Volume
×
{
1
+
gain
×
Δ
T
control
Target
T
control
}
wherein Measured T control and Target T control are the currently measured and setpoint values of the control temperature, respectively; Current Volume and Updated Volume are volumes of the working fluid for the current cycle and subsequent cycles, respectively; and gain is a parameter ranging from 0 to 1.
29 . The method of claim 28 , wherein Measured T control is the value of the control temperature as measured during the most recently completed cycle.
30 . The method of claim 28 , wherein Measured T control is a moving average based on the values of the control temperature as measured during a preselected number of the most recently completed cycles.
31 . The method of claim 27 , wherein the final control setpoint is reached by operating the method through a sequence comprising a plurality of stepwise increments, an incremental control temperature setpoint being associated with each of the stepwise increments, and during at least some of the cycles within at least some of the stepwise increments, the preselected amount of subcooled working fluid is adaptively adjusted to urge the measured control temperature to reach the incremental control temperature setpoint associated with that increment, and the adaptive adjustment comprises changing the preselected amount of subcooled working fluid in accordance with the formulas:
Δ
T
control
=
Target
T
control
-
Measured
T
control
Updated
Volume
=
Current
Volume
×
{
1
+
gain
×
Δ
T
control
Target
T
control
}
wherein Measured T control and Target T control are the currently measured and setpoint values of T control , respectively; Current Volume and Updated Volume are volumes of the working fluid for the current cycle and subsequent cycles, respectively; and gain is a parameter ranging from 0 to 1.
32 . The method of claim 31 , wherein the adaptive adjustment is carried out during at least some of the cycles of each of the stepwise increments.
33 . The method of claim 31 , wherein Measured T control is the value of the control temperature as measured during the most recently completed cycle.
34 . The method of claim 31 , wherein Measured T control is a moving average based on the values of the control temperature as measured during a preselected number of the most recently completed cycles.
35 . The method of claim 31 , wherein the method is additionally operated in an initial increment carried out prior to the sequence of stepwise increments and without adaptive adjustment of the preselected amount of subcooled working fluid.
36 . The method of claim 31 , wherein each of the stepwise increments is carried out for a duration of at least a stabilizing interval associated with that stepwise increment.
37 . The method of claim 36 , wherein each of the stepwise increments is carried out for the duration of the stabilizing interval associated with that stepwise increment.
38 . The method of claim 31 , wherein each of the stepwise increments is terminated when the control temperature reaches the incremental control temperature setpoint associated with that increment.
39 . The method of claim 27 , wherein the control temperature is the cold side temperature.
40 . The method of claim 27 , wherein the control temperature is switched between the cold side temperature and the reservoir temperature during operation of the method.Join the waitlist — get patent alerts
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