WO2025264391A1

WO2025264391A1 - Thermal harvesting management with multiple heat sources

Info

Publication number: WO2025264391A1
Application number: PCT/US2025/032281
Authority: WO
Inventors: Samer Taha; Benjie N. Limketkai
Original assignee: Atoco Inc
Current assignee: Atoco Inc
Priority date: 2024-06-21
Filing date: 2025-06-04
Publication date: 2025-12-26
Anticipated expiration: 2026-12-21

Abstract

This invention related to a system configured to circulate a thermal fluid in a circulation loop connected to at least one flow control valve, where the system includes the thermal fluid; one or more heat exchangers; at least one flow control valve configured to redirect a thermal fluid flow to contact the heat exchanger connected to one or more thermal elements; and a controller configured to set states of the flow control valves to configure a thermal fluid path and control transfer of thermal energy from the thermal elements. This invention also related to a method for circulating a thermal fluid in a circulation loop connected to at least one flow control valve.

Description

Title of the Invention

Thermal Harvesting Management With Multiple Heat Sources

Field of the invention

This invention is related to a design and method of managing and optimizing the heat transfer from multiple heat sources to one or more heat-consuming elements. The invention relates to a method to manage the heat transfer from exogeneous and endogenous heat sources to a temperature-vacuum swing adsorption (TVSA) system.

Background

Systems that operate by consuming thermal energy can improve energy efficiency by recycling tire endogenous heat generated and/or harvesting exogenous heat energy. Example systems include a temperature-vacuum swing adsorption (TVSA) or temperature swing adsorption (TSA) system, where if thermal energy can be recycled or supplemented from ambient sources, then it will lower the overall thermal energy consumption of the system. In addition, timing when to combine the thermal energy from the waste or ambient heat sources and system-generated thermal energy can also be optimized. However, often times, the thermal energy produced from these various sources are not constant, vary over time, and unreliable. Therefore, this invention is related to employing a system and method to manage the thermal energy inputs fr om multiple sources and utilize their thermal energy opportunistically by controlling the circulating thermal fluid path contacting the various heat- source and heat-consuming elements. A thermal element is defined as a heat-source or heat- consuming element.

A heat-source element provides thermal energy that needs to be harvested and collected and transferred to the heat-consuming elements of the system. When the circulating thermal fluid comes into contact with the heat-source elements, the temperature of the thermal fluid should increase. A heat-consuming element should receive thermal energy from the circulating thermal fluid to reduce the thermal fluid’s temperature.

Depending on the state of the system operation, the same element can either be a heat- source or heat-consuming element at any given point of time. An example thermal element is a thermal storage device that stores thermal energy. The thermal storage device can operate as a heat-source element by transferring its stored thermal energy to a circulating thermal fluid that contacts it, or as a heat-consuming element by receiving thermal energy upon contact with a circulating thermal fluid.

Summary of Invention:

This and other objects have been achieved by the present invention. One object of the present invention is to provide a system configured to circulate a thermal fluid in a circulation loop connected to at least one flow control valve, the system comprising: the thermal fluid; at least one heat exchanger: the at least one flow control valve configured to redirect a flow of the thermal fluid to contact the at least one heat exchanger connected to at last one thermal element, the at least one flow control valve can be reconfigured to change a circulation of the thermal fluid to contact or bypass the at least one thermal element; the at least one thermal element selected from the group consisting of a heat- source, a heat-storage, and a heat-consuming element; and a controller configured, based on sensor measurements comprising a temperature, to set states of the at least flow control valve to configure a thermal fluid path and to control transfer of thermal energy from the at least thermal element between the at least thermal element and the thermal fluid. In one embodiment, the system further comprises a main circulation loop, wherein the main circulation loop is a serpentine comprising at least one segment, wherein each segment is connected to the at last one flow control valve that can optionally redirect the flow of the thermal fluid to contact or bypass the at least one thermal element in the system.

In another embodiment, in the system, the at least flow control valve is configured to control a circulation of the thermal fluid to contact the at least one thermal element in any order.

In another embodiment, in the system, the at least one thermal element comprises the at least one heat exchanger configured to harvest thermal energy from at least one source selected form the group consisting of ambient air heat, adsorption energy for gas adsorbing onto a sorbent, solar irradiation energy, waste heat generated from vacuum pump, heat generated when gas is condensed on a surface, and heat from an output gas or a liquid stream from an industrial process.

In another embodiment, in the system, the at least one thermal element is a heat- consuming element comprising a sorbent inside a vacuum chamber that is connected to a vacuum pump to lower pressure inside the vacuum chamber to desorb adsorbed gas molecules in the sorbent wherein: a. the sorbent is connected to the at least one heat exchanger contacting a circulating thermal fluid; b. at least one of the heat-source elements is an electric-based heater; c. based on current temperature conditions of the thermal fluid, historical, current, or forecasted temperature conditions of external environment, and/or gas partial pressure conditions inside and outside the heat-consuming element chamber, the controller is further configured to set a flowrate of the thermal fluid and/or time when the thermal fluid contacts the sorbent connected to the at least heat exchanger and when an electric-based heating is turned on to heat the thermal fluid or heat up the sorbent directly.

A further object of the present invention is to provide a method for circulating a thermal fluid in a circulation loop connected to at least one flow control valve, comprising: redirecting a flow of the thermal fluid to contact at least one heat exchanger connected to at last one thermal element using at least one flow control valve, wherein the at least one flow control valve changes a circulation of the thermal fluid to contact or bypass the at least one thermal element, wherein the at least one thermal element is selected from the group consisting of a heat-source, a heat-storage, and a heat-consuming element; and based on sensor measurements comprising a temperature, setting a state of the at least flow control valve by using a controller to configure a thermal fluid path and controlling a transfer of thermal energy from the at least thermal element between the at least thermal element and the thermal fluid.

In one embodiment, in the method, the circulation loop comprises a main circulation loop, wherein the main circulation loop is a serpentine comprising at least one segment, and wherein each segment is connected to the at last one flow control valve that optionally redirects the flow of the thermal fluid to contact or bypass the at least one thermal element.

In another embodiment, the method further comprises controlling, using the at least flow control valve, a circulation of the thermal fluid such that the thermal fluid contacts the at least one thermal element in any order.

In another embodiment, in the method, the at least one thermal element comprises the at least one heat exchanger which is configured to harvest thermal energy from at least one source selected from the group consisting of ambient air heat, adsorption energy for gas adsorbing onto a sorbent, solar irradiation energy, waste heat generated from vacuum pump, heat generated when gas is condensed on a surface, and heat from an output gas or a liquid stream from an industrial process.

In another embodiment, in the method, the at least one thermal element is a heat- consuming element comprising a sorbent inside a vacuum chamber that is connected to a vacuum pump to lower pressure inside the vacuum chamber to desorb adsorbed gas molecules in the sorbent, wherein: d. the sorbent is connected to the at least one heat exchanger contacting a circulating thermal fluid; e. at least one of the heat-source elements is an electric-based heater; f. based on current temperature conditions of the thermal fluid, historical, current, or forecasted temperature conditions of external environment, and/or gas partial pressure conditions inside and outside the heat-consuming element chamber, setting, using the controller, a flowrate of the thermal fluid and/or time when the thermal fluid contacts the sorbent connected to the at least heat exchanger and when an electric-based heating is turned on to heat the thermal fluid or heat up the sorbent directly.

Brief Description of The Drawings

The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the office upon request and payment of the necessary' fee.

A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: Figure 1 illustrates multiple heat sources whose thermal energy needs to be transferred and combined to operate a heat-consuming element of the system.

Figure 2a illustrates a thermal fluid circulating in a serpentine loop, where each segment of the serpentine contacts every thermal element through valves. The states of the valves can be configured to redirect the thermal fluid flow such that the circulating thermal fluid can contact or bypass any of the thermal elements in any desired order.

Figure 2b illustrates one embodiment of shut-off valves at two example intersection points between the serpentine loop and thermal element pipes.

Figure 3a is a schematic illustration showing one configuration of the valve states to produce a specific thermal fluid circulation path.

Figure 3b is a schematic illustration showing another configuration of the valve states to produce another thermal fluid flow path in which a thermal element is bypassed and does not contact the circulating thermal fluid.

Figure 4 illustrates the serpentine design with segment-bypass valves that can be used to bypass a segment of the serpentine to shorten the distance the thermal fluid has to travel in its circulating path.

Figure 5 illustrates a variation of the serpentine design where some segments of the serpentine are shortened and not connected to some thermal elements. This can be used when the circulating thermal fluid will always contact some thermal elements before contacting another set of thermal elements.

Figure 6 illustrates a variation of the serpentine design where there is only a single serpentine segment. This can be used when the circulating thermal fluid will always contact the thermal elements in a specific order and the valves only control whether the thermal fluid bypasses a thermal element or not. Figure 7 illustrates the single main loop design connected to multiple heat-source elements and heat-consuming elements.

Figure 8 illustrates a two-loops design which is a single main loop that can be divided into two loops where each loop is connected to separate circulation pumps for two independent thermal fluid circulation.

Figure 9 illustrates a temperature-vacuum swing adsorption (TVS A) system employing the two-loops design.

Detailed Description of the Embodiments

All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. Further, the materials, methods, and examples are illustrative only and are not intended to be limiting, unless otherwise specified.

This invention employs a thermal fluid, also referred to as a heat transfer fluid, which may be in the form of a liquid or gas, that is circulated within the system through pipes, ducts, and/or other conduits or passages where the flow of the fluid can be directed to selectively contact one or more heat-source and/or heat-consuming elements in a re- configurable sequence. The order of the thermal fluid circulation pathway can be changed at any point in time to optimize the thermal energy transfer in the system. The invention replates to one or more systems that can harvest ambient or waste heat and transfer and utilize their thermal energy in an efficient method that compliments endogenously supplied heat to operate the system at temperatures that provide efficient operate of the system.

Figure 1 illustrates a temperature-vacuum swing adsorption (TVS A) system that uses thermal energy to regenerate a sorbent to desorb a target species for collection. Chamber D (100) is connected to a vacuum pump to desorb the adsorbed atoms or molecules in a sorbent material (101). In order to desorb the adsorbates, a vacuum pump is used to lower the pressure in the chamber 100. Thermal energy is supplied to the sorbent 101 through a heat- exchanger element 102 that can be a heat exchanger coil containing a circulating thermal transfer fluid. A heat- exchanger element 103, that can be a thermal conductor that is electrically heated to provide thermal energy, can supply additional thermal energy to the sorbent. The sorbent is heated to increase and maintain the rate of desorption of the adsorbate molecules as they are pulled and collected through the vacuum pump. The heat-exchanger element 102 has a circulating thermal fluid that collects thermal energy from multiple sources, including but not limited to adsorption energy harvested from another sorbent 111 that is adsorbing molecules, ambient air heat energy harvested from a heat exchanger 120, and solar irradiation energy harvested from a solar heater 130.

An object of the present invention is to provide a system and a method to manage the thermal energy harvested from various heat sources and combine and transfer the collected thermal energy to one or more heat-consuming elements for maximum utilization of the available thermal energy. In one embodiment, a system transfers the thermal energy from multiple heat sources in any order to a circulating thermal fluid. The ability to reconfigure the order the circulating fluid contacts the various heat source elements lets the system optimize the amount of heat energy that can be collected and combined . The circulating thermal fluid pathway can be configured such that the order it contacts the heat-source elements is such that thermal energy is transferred from the heat-source elements to the thermal fluid to maximize the temperature of the thermal fluid. Thermal energy generated from electricity can supply additional thermal energy that is either applied directly to the heat-consuming element or added to the thermal transfer fluid that is then later contacted to the heat-consuming element. In Figure 1, the heat-consuming element is the desorption chamber D 100 wherein thermal energy is supplied to the sorbent 101. The electrical heater element 103 is drawn as heating the sorbent directly, but it can also be considered a separate heat-source element that transfers thermal energy to a circulating thermal fluid that then later contacts the sorbent 101 through a heat-exchanger element 102. The heat-source elements illustrated in Figure 1 are heat from adsorption energy harvested in a sorbent 111, heat from ambient air by a heat exchanger 120, and heat from solar irradiation harvested by a solar concentrator 130. Additional heat source elements not shown in Figure 1 can also include harvested heat energy from waste heat output streams from within the system or from the exogeneous sources, such as industrial waste heat output streams.

Figure 2a illustrates an embodiment wherein a thermal fluid circulates in a serpentine loop 220, where along each segment of the serpentine (221, 222, 223, 224), the thermal fluid flow can get redirected to/from the serpentine from/to any of the thermal elements (200, 201, 202, 203) through intersection points, such as 230 drawn as circles, comprised of one or more valves. The serpentine loop 220, drawn with a dashed line, can be comprised of piping carrying a thermal fluid connected to a circulator pump 290 to push the fluid in constant circulation. There are additional pipes 210 - 217 that are directly connected to the thermal elements 200 - 203 that can carry' the thermal fluid from the serpentine to contact one or more of the thermal elements. These pipes 210 - 217 that are not part of the serpentine loop 220 and are connected to one of the thermal elements 200 - 203 are called thermal element pipes. The intersection points, drawn as circles, indicate where the circulating thermal fluid can move between the serpentine loop 220 and one of the thermal element pipes 210 - 217. For example, the thermal fluid can exit thermal element 202 and go through thermal element pipe 214 and get back to the serpentine loop 220 through the intersection point 230. The states of the valves at all the intersection points can be configured to control the thermal fluid flow such that the circulating thermal fluid can contact or bypass any of the thermal elements 200- 203 in any desired order.

In this embodiment, there are 4 thermal elements 200-203 connected to pipes 210-

217. The thermal fluid circulating in the serpentine loop 220 can transfer between the serpentine loop and the pipes 210-217 to contact the thermal elements through one or more flow-control valves, such as 230. If n is the number of thermal elements, then in this embodiment, the number of intersections, such as 230, is 2 times n squared. There are also n segments in the serpentine path 220. Each intersection between the serpentine loop 220 and the thermal element pipes 210-217 can include but not limited to 2 on-off valves, or shut-off valves, to redirect the circulating thermal fluid from/to the serpentine to/from the thermal element pipes. lUn one embodiment a third on-off valve at each intersection controls the direction of the circulating thermal fluid such that once it leaves or enters the thermal element pipe, the fluid goes in one direction in the thermal element pipe 210 - 217.

Figure 2b illustrates one example arrangement of shut-off valves at two example intersection points between the serpentine loop 220 and thermal element pipes 212 and 213 that are connected to thermal element 201. The intersection points between the serpentine loop 220 and the thermal element pipes 212 and 213 are indicated by circles. The circles are filled in with solid color to indicate that the shut-off valve elements (drawn as triangles) are configured to redirect the fluid flow between the serpentine loop and thermal element pipe. If the intersection point circle is unfilled and not drawn with solid color, then this indicates that the shut-off valve elements are configured such that the fluid flow does not redirect between the serpentine loop and thermal element pipe. For example, if the thermal fluid flow is in the serpentine and reaches an intersection point drawn with an unfilled circle, then the shut-off valves around that intersection point are set such that the fluid flow does not get redirected into the thermal element pipes but remains flowing in the serpentine loop. The intersection points drawn with circles are not physical elements but are for illustration to show possible areas where the fluid flow can transfer between the serpentine and thermal element pipes. The circulator pump 290 moves the thermal fluid to circulate around the serpentine path 220 in one direction (drawn as clockwise direction). The flow does not contact thermal element 201 unless the flow gets redirected through the intersection points 231 and 232. In one embodiment, each intersection point is comprised of three shut-off valves. The shut-off valves are drawn as triangles. The triangles are filled with solid color to indicate the shut-off valve is in the open or “on” state and flow can go through it. If the triangle is unfilled and not drawn with solid color, then this indicates the shut-off valve is closed or in the “off’ statement and the fluid is prevented from flowing through the shut-off valve. In this illustration, the thermal fluid goes to intersection point 231, where shut-off valve 231a is open while the other two shut-off valves 231b and 231c are closed. This forces the thermal fluid flow to go from the serpentine 220 and into the thermal element pipe 213. However, since only shut-off valve 231a is open while valve 231c is closed, the flow only goes in one direction in the thermal element pipe 213 towards thermal element 201. After contacting thermal element 201, the thermal fluid flow exits through pipe 212 and the flow is redirected back into the serpentine 220 because shut-off valve 232b and 232c are closed. Closed shut- off valve 232c prevents flow from going further down the pipe 212 and closed shut-off valve 232b prevents from flow going in the other direction in the serpentine loop. This figure only shows two intersection points, but other drawn intersection points in Figure 2a can follow similar shut-off valve arrangement such as to control the circulating thermal fluid flowdirection. By controlling the states of all the shut-off valves at all the intersection points, any arbitrary fluid flow path can be configured to contact or bypass any thermal element at any arbitrary order.

Figure 3a is a schematic illustration showing one configuration of the valve states to produce a specific thermal fluid circulation path. In this example, the filled-in circle indicates that the shu t-off valves at that intersection point are configured such that the circulating fluid moves to/from the serpentine loop 320 and into one of the pipes directly connected to one of the thermal elements 300 - 303 following the flow directions indicated by the arrows. The arrows indicate the flow direction of the circulating thermal fluid. In both Figures 3a and 3b, the circulating thermal fluid is moved by the circulator pump 390. In this particular configuration, the thermal fluid moves from the serpentine to the pipe 313 at intersection 331 to contact thermal element 301. As shown in Figure 2b, the intersection 331 can be comprised of three shut-off valves to redirect the thermal fluid flow from the serpentine loop 320 into the pipe 313 such that the flow only goes straight to the thermal element 301 from the serpentine loop 320. As indicated by the arrows, the flow direction of the thermal fluid does not go to the end of the pipe 313, but goes straight towards the thermal element 301 and neither it continues going along the serpentine 320 but go straight to pipe 313. After contacting thermal element 301, the thermal fluid flow moves back to the serpentine loop 320 through the intersection 332. Similarly, in this particular configuration, the intersection 332 has one or more valves such that the flow direction does not continue down pipe 312 past the intersection 332, but it gets redirected completely to the serpentine loop 320. After flowing into the serpentine loop 320, the thermal fluid does not backflow towards intersection 333, but moves in one direction in the serpentine loop. The thermal fluid then goes into serpentine segment 322 where it again moves from the serpentine down to the pipe connecting to thermal element 300 through the intersection 334. After the thermal fluid contacts thermal element 300, it flows back to the serpentine through intersection 335. It then contacts thermal element 302 and thermal element 303 before making it back up to the serpentine and circulating back to intersection 331 to contact thermal element 301 again.

Figure 3b is a schematic illustration showing another configuration of the valve states to produce another thermal fluid flow path but in this configuration of shut-off valve states, thermal element 301 is bypassed and the circulating thermal fluid pathway does not contact it. The circulating thermal fluid flows through the serpentine segment 321 without going to any of the thermal elements. Unlike in Figure 3a, the shut-off valves at intersections 331 and 332 are configured such that fluid flow stays in the serpentine and does not get redirected to thermal element pipes 313 or 312. The thermal fluid flow continues to the next serpentine segment where the fluid flow does get redirected and exit the serpentine and contacts thermal element 300.

Figure 4 illustrates the serpentine design with segment-bypass valves 425, 426, 427, and 428 that can be used to bypass serpentine segment 421, 422, 423, and 424, respectively. Similarly to how there are 3 shut-off valves at each intersection, in this embodiment, there are also three shut-off valves for each bypass section. To bypass segment 421, there are three shut-off valve elements 425, 440, and 441. The shut-off valves are draw n as triangles and are either filled in with solid color to indicate it is on or open (pennits fluid flow through) or not filled in with a solid color to indicate it is off or closed (prevents fluid from flowing through it). In this particular shut-off valve configuration, the circulating thermal fluid bypasses segment 421 with open shut-off valve 425 and closed shut-off valves 440 and 441. Shut-off valves 440 and 441 are closed to prevent the thermal fluid flow from going into segment 421. Shut-off valves 425 is open such that the circulating thermal fluid flow bypasses segment 421 and goes straight to segment 422. The purpose of the bypass valves (shut-off valves 425, 440, and 441 for the segment 421 bypass section) is to shorten the distance the thermal fluid has to travel in its circulating path. The order of thermal elements contacted is the same for both Figure 3b and Figure 4. The only difference is Figure 4 bypasses segment 421 completely because the thermal fluid does not get redirected to go contact any of the thermal elements, so that segment of the serpentine can be bypassed to shorten the total distance the thermal fluid has to travel before making a complete circulation loop. In this illustration, the thermal fluid is moved around in a loop by the circulator pump 490.

Figure 5 illustrates a variation of the serpentine design where some segments of the serpentine are shortened and not connected to one or more thermal elements. This can be employed when the design detennines that the circulating thermal fluid will always contact one or more thermal elements before contacting another set of one or more thermal elements. In this embodiment, the first two serpentine segments drawn on the left have been shortened such that the thermal fluid can only contact thermal elements 502 and 503 from these segments. The next two segments, 523 and 524, remove some intersection points such that thermal fluid flowing through these segments cannot get redirected to the thermal element pipes that contact thermal elements 500 and 501. Given the circulation direction of the thermal fluid flow, the system has been designed knowing that the circulating thermal fluid only contacts thermal elements 502 and/or 503 before or after 500 and/or 501. If the order the thermal fluid can be configured to contact the thermal elements is not completely arbitrary, then the serpentine design can be modified by reducing serpentine segment length and also removing shut-off valves (by removing intersection points between the serpentine loop and the thermal element pipes). In this embodiment, the bypass valves are included. In this configuration of shut-off valve states, the circulating thermal fluid in serpentine loop 520 does not contact thermal elements 502 and 503. The fluid flow bypasses the first two serpentine segments by flowing through bypass valves 525 and 526. The thermal fluid then enters segment 523 where it gets redirected from the serpentine into the thermal element pipes to contact thermal element 501. After contacting thermal element 501, the thermal fluid bypasses segment 524 through bypass shut-off valve 528. The circulating thermal fluid flow also does not contact thermal element 500. In this Figure 5, the thermal fluid is moved by the circulator pump 590.

Figure 6 illustrates a variation of the serpentine design where there is only a single serpentine segment. In this reduced design, the main circulation pathway is no longer a serpentine but a single main loop. The circulating thermal fluid in this main loop can be redirected to the thermal element pipes connecting to the thermal elements through the shut- off valves. This design reduces the number of intersection points to only the number of thermal elements. In the most robust design shown in Figure 2a, the thermal fluid circulation can be configured to contact or bypass any of the thermal elements in any order. The number of intersection points equaled 2 times n squared, where n is the number of thermal elements. In this embodiment, the number of intersection points is equal to n. Each intersection point is still comprised of three shut-off valves. This design fixes the order of thermal elements that the thermal fluid contacts. The circulating thermal fluid will always contact the thermal elements in a specific order and the shut-off valves only control whether the thermal fluid bypasses a thermal element or not. In the shut-off valve configuration shown in Figure 6, the circulating thermal fluid in the main loop 620 first contacts thermal element 600 by going through shut-off valve 640b and exiting through shut-off valve 640c. Shut-off valve 640a is closed to prevent a portion of the thermal fluid from bypassing thermal element 600. After contacting thermal element 600, the thermal fluid bypasses completely both thermal elements 601 and 602 and flows through open shut-off valves 641a and 642a. After flowing through shut-off valve 642a, the thermal fluid goes through open shut-off valve 643b to contact thermal element 603 and then exits through shut-off valve 643c to then complete the loop. The thermal fluid circulates in the 620 loop by the circulator pump 690.

Figure 7 illustrates the single main loop design connected to multiple heat-source elements and heat-consuming elements. The thermal fluid is moved around the single main loop 720 by the circulator pump 790. For purpose of illustration, the thermal elements in Figure 1 are used in this embodiment. The heat-source element 700 is the chamber 110 that is adsorbing molecules to produce adsorption thermal energy. The heat-source element 701 is the ambient air heat harvester from element 120 in Figure 1. The heat-source element 702 is a solar heater from element 130 in Figure 1. The heat-consuming element 703 is the chamber 100 that is desorbing molecules through a vacuum pump. In addition, this embodiment includes two thermal storage elements 704 and 705 that can act as a heat-consuming or a heat-source element. The thermal element 700 is a heat-source element where adsorption energy gained by the sorbent 750 is transferred to a heat exchanger that transfers the thermal energy to the circulating thermal fluid that contacts thermal element 700 by entering through shut-off valve 740b and then exiting through valve 740c. The thermal element 700 bypass valve 740a is closed so that all the thermal fluid flow does not bypass thermal element 700. In this configuration of shut-off valves, the circulating thermal fluid gains thermal energy from thermal element 700 but bypasses thermal elements 701 and 702 through bypass valves 741a and 742a. The thermal energy from the circulating thermal fluid is then transferred to heat-consuming element 703 through a heat exchanger to transfer to the sorbent 751. The bypass shut-off valve 743a is closed so that none of the thermal fluid will bypass the heat- consuming element 703. After contacting the heat-consuming element 703, any residual thermal energy can be stored in thermal storage element 705 since the bypass valve 744a is closed and valves 744b and 744c are open to direct the flow of the thermal fluid to contact thermal element 705. The thermal storage elements 704 and 705 are comprised of heat exchanger elements that flow the thermal fluid to exchange energy with a thermal storage medium 752 and 753, respectively. This particular configuration of valve states has the thermal fluid bypass the thermal storage element 704 through bypass valve 745a with valves 745b and 745c closed. In some embodiments, the thermal fluid can contact both thermal storage elements or bypass one or bypass both, depending on the temperatures of the thermal fluid and thermal storage mediums. The system can be configured at any time to control the flow of the thermal fluid based on the temperatures of the thermal fluid and thermal storage mediums to control the direction of thermal energy transfer between the thermal fluid and thermal storage medium. For example, there can be a situation where the heat-source elements can only increase the temperature of the thermal fluid to T1 degrees while the thermal storage medium are at temperature T2, which is greater than T1 degrees. In this situation, the system can configure the shut-off valves such that the circulating thermal fluid does not contact the thermal storage elements so that the temperature of the thermal storage medium does not decrease since the heat-source elements are at a lower temperature.

Figure 8 illustrates a two-loops design where the main circulation loop can be split into two separate and independent circulation loops by employing a set of valves at a dividing point 860. In the current drawn configuration for the valves at the dividing point 860, shut-off valves 861 and 862 are open and shut-off valves 863 and 864 are closed. In this configuration, thermal fluid can flow in the 820 and the 821 circulation loops independently. To operate both circulation loops independently, circulator pumps 890 and 891 are connected to each separate circulation loops 820 and 821, respectively. The main loop is divided into two circulation loops and consequently, the thermal fluid circulating in the 820 loop can only contact thermal elements 802, 803, and 805, while the thermal fluid circulating in the 821 loop can only contact thermal elements 800, 801, and 804. The advantage of operating two independent loops is to be able to do thermal heat transfers under two different conditions simultaneously. For example, the thermal fluid circulating in the 820 loop transfers thermal energy collected from the solar heater 802 to heat up the sorbent in the desorption chamber 803 and any excess thermal energy can be stored in a temperature reservoir 805 and after that, recirculate back to be reheated by the solar heater 802. The separate thermal fluid circulation in the 821 loop is collecting adsorption energy produced from the 800 chamber and raising the temperature further from the ambient air heat collector 801 which is then transferred to the temperature reservoir 804 to store the thermal energy harvested from the ambient air. The heating of the desorption chamber heat-consuming element 803 from the thermal energy collected from the solar heater 802 is done in parallel with the storage of thermal energy in the thermal storage 804 from the harvested thermal energy from the ambient air harvesting heat-source element 801.

Figure 9 illustrates an embodiment of the invention that implements of the two- loops design for the temperature-vacuum swing adsorption (TVS A) system. The shut-off valves 961, 962, 963, and 964 can be set two run two independent thermal fluid circulations. To simplify the drawing, the circulation pumps have not been drawn in, but arrows are drawn to indicate the direction of the thermal fluid flow pushed by circulator pumps. Thermal element 900 is a chamber with a sorbent 950 that is adsorbing gas molecules, such as water vapor or carbon dioxide gas. Thermal element 901 is an ambient air heat exchanger. Thermal element 902 is a solar heater that transfer thermal energy from solar irradiation to the thermal fluid that contacts it. Thermal element 903 is the heat-consuming element that contains the sorbent 951 in a vacuum chamber that desorbs the gas molecules adsorbed in the sorbent. A heat exchanger element 953 is used to transfer thermal energy from the thermal fluid to the sorbent 951. In order to supply extra thermal energy beyond that is supplied from the circulating thermal fluid, an electric heater 952 is contacted to the sorbent 951. In this embodiment, the electrical heater is contacted directly to the sorbent, but as a more general method, the electric heater can be treated as a heat-source element that heats the thermal fluid that contacts it. The desorbed gas molecules, such as water vapor or carbon dioxide gas, is taken up by the vacuum pump and then condensed or compressed into a separate condensation module. In order to set the states of all the shut-off valves based on the desired thermal fluid flow, a control unit 970 is employed to open and close the various shut-off valves depending on input data, including but not limited to temperahire and gas pressure sensor readings at each thermal element, ambient temperature, time of day, thermal fluid flow rate, and etc. In Figure 9, the invention illustrates an ambient-heat assisted vacuum-based system designed for enhancing the energy efficiency of capturing a specific gas or gasses, including but not limited to water vapor or carbon dioxide gas, out of the ambient air based on adsorption and desorption processes using sorbents. In the following, one embodiment for the system in Figure 9 for capturing water from ambient air is described, but the principle can be applied to other gases.

The system comprises at least a chamber that contains a sorbent 951 that adsorbs gas molecules. After the adsorption phase where the sorbent adsorbs a certain amount of gas molecules, a vacuum pump is turned on to lower the pressure inside the chamber 903 in order to desorb the gas molecules from the sorbent 951. Thermal heating is applied to the sorbent material to continue the desorption process of the gas molecules at a specific pressure maintained by the vacuum pump. The thermal heating of the sorbent during the desorption phase is applied by electricity-based heating showed as 952, which can include but is not limited to electric resistance heating, magnetic induction heating, and/or microwave heating, and heating through thermal transfer from a thermal fluid contacting a heat exchanger 953. The circulating thermal fluid collects thermal energy from one or more heat-sources, including but not limited to ambient air contacting a heat exchanger 901, solar irradiation energy heater 902, and adsorption heat from another sorbent 950 that is in the phase of adsorbing gas molecules blown through by a fan into chamber 900. Although not illustrated in Figure 9, other sources of thermal energy transferred to the circulating thermal fluid can include heat from the output of industrial waste output stream, condensation energy when the desorbed gas, such as water or carbon dioxide, is condensed from the output of the vacuum pump, waste heat from the operation of the vacuum pump, or heat generated from burning a fuel source, such as diesel. The vacuum pump connected to the chamber operates to create a partial pressure in the chamber during the desorption process to desorb the water molecules out of the sorbent material. The desorbed water molecules that are collected by the vacuum pump are then sent to a condensation module that condenses the humid stream by applying a higher relative pressure and/or by cooling. This condensation energy can also potentially be collected through heat transfer to the circulating thermal fluid.

The control unit 970 comprises a computer module that runs an algorithm that takes as inputs measurements from sensors in the system and data from an internet server through any possible loT, or internet of things, connection. The control unit takes any and all available inputs from the following: amount of water harvested in the last specific number of hours, previous day minimum temperature, previous day maximum temperature, previous day average temperature, previous day minimum relative humidity, previous day maximum relative humidity, previous day average relative humidity, previous day maximum solar radiation intensity, previous day average solar radiation intensity, current temperature, current relative humidity, current solar radiation intensity, current daytime duration, forecasted maximum temperature in the coming 24 hours, forecasted minimum temperature in the coming 24 hours, forecasted maximum temperature in the coming 24 hours, forecasted minimum relative humidity in the coming 24 hours, forecasted maximum temperature in the coming 24 hours, forecasted maximum radiation intensity in the coming 24 hours, forecasted average radiation intensity in the coming 24 hours. The control unit keeps revisiting and checking all the previous, current and forecasted ambient parameters every set duration of time, to recalculate and update its optimal water harvesting plan.

In Figure 9, multiple sensors can read the temperature Ts of the sorbent in the desorption chamber 903, temperature T1 of the thermal fluid after contacting or bypassing the adsorption chamber 900, temperature T2 of the thermal fluid after contacting or bypassing the thermal storage 905, temperature T3 of the thermal fluid after contacting or bypassing the desorption chamber 903, temperature T4 of the thermal fluid after contacting the ambient air heat exchanger 901, and temperature T5 of thermal fluid after contacting or bypassing the solar heater 902.

The control unit can run the system in various operation modes. The control unit can set the optimal path of the circulating thermal fluid by controlling the open or closed states of the shut-off valves. It can determine the optimal path based on various inputs and parameters, including but not limited to the gas molecules adsorption and/or desorption rate, ambient temperature, temperature of the thermal storage, the solar heater power, and other sensor readings from the system.

In the “maximum daily water generation” operation mode, the control unit runs an algorithm to determine the best plan for harvesting maximum possible amount of water throughout the next 24 hours based on the current and forecasted ambient conditions, regardless of the energy efficiency. The control unit also determines optimal rates for circulating the thermal transfer fluid and for the fans that move ambient air in the adsorption process. After one sorbent has completed the adsorption process and is now about to start the desorption process, another sorbent is about to start the adsorption process. Based on the volume of Chamber D 903, the mass of the sorbent material 951, its specific desorption characteristics and the strength of the vacuum pump, an optimal temperature Topt for the sorbent can be determined in terms of achieving maximum water desorption using the minimum total heating energy. The desorption process starts with the vacuum pump creating a partial pressure in Chamber D 903; and:

If T5 > Ts AND Ts < Topt, the shut-off valves 943b and 943c are opened and bypass shut-off valve 943a is closed so that the thermal transfer fluid contacts the sorbent 951 to heat it to a higher temperature. Concurrently, the electricity-based heating 952 can also be activated until Ts equals Topt. Ts is the current temperature of the sorbent 951 measured by a temperature sensor. ELSE, if T5 < Ts AND Ts < Topt, the electricity-based heating 952 is turned on until

Ts equals Topt. In addition, shut-off valves 943b and 943c are closed and bypass shut-off valve 943a is opened so that the circulating thermal fluid bypasses the chamber 903 and it can optionally contact the thermal storage 905 if the temperature T3 of the thermal fluid is higher than the temperature of the thermal storage 905. Since T5 < TS, the thermal fluid bypasses the thermal element 903 so that the temperature TS of the sorbent 951 is not lowered by contacting the thermal fluid that is at a lower temperature T5.

ELSE, if Ts >= Topt, the electricity-based heating 952 is turned off and shut-off valves 943b and 943c are closed and bypass shut-off valve 943a is opened so that the circulating thermal fluid bypasses the chamber 903 and it can optionally contact the thermal storage 905 if the temperature T3 of the thermal fluid is higher than the temperature of the thermal storage 905.

If T2 >= T4, shut-off valves 964 and 963 are closed and shut-off valve 962 is opened so that the circulating thermal fluid contacting or bypassing the thermal storage 905 gets redirected to the solar heater 902 and bypasses the thermal elements 900 and 901 completely. Since T2>= T4, the thermal fluid should not contact the thermal element 901 since its temperature T4 will lower the temperature T2 of the thermal fluid. To prevent the thermal fluid from contacting thermal element T4, the circulation can bypass by turning off shut-off valve 964.

ELSE, if T2 < T4, shut-off valves 961 and 962 are closed and shut-off valves 963 and 964 are opened so that the thermal fluid increases its temperature by potentially contacting heat exchanger elements in heat-sources 900 and 901.

If T1 >= T4, shut-off valves 941b and 941c are closed and shut-off valve 941a is opened so that the thermal fluid bypasses the ambient air heat exchanger and goes to the solar heater 902. This can happen when the temperature of the ambient air is colder than the temperature generated from the adsorption process in sorbent 950 and/or the temperahire generated from a solar heater 902.

ELSE, if Tl< T4, shut-off valves 941b and 941c are opened and bypass shut-off valve 941a is closed so that the thermal fluid contacts the ambient heat exchanger 901 and then continues to the solar heater 902.

In a “specific daily water generation target” operation mode, the logic is similar to the “maximum daily water generation” operation mode, but the key difference is that the control unit 970 optimizes the operation of the system such that a specific daily target is achieved whenever possible, but with the minimum possible total external energy consumption. Thus, the system prioritizes the utilization of the thermal heat harvested from ambient air in 901, from adsorption heat in 900 and/or from the solar heater 902 and will activate the electricity- based heating from 952 only when/if necessary to achieve the daily target. If the specified daily water generation is achieved before the end of the 24 hours period, the system hibernates. If, based measured and forecasted ambient data, the control unit 970 determines that it is likely to achieve the specific daily water generation target based on only the total combined ambient energy collected from 900, 901, and 902, the control unit continues operating without engaging the electricity-based heating 952. If by evening time, the system has not achieved the specific daily target and the remaining stored thermal energy in 905 is insufficient to complete the target, the control unit engages the electricity-based heating from 952 to support the system to achieve the specified daily water generation target.

In the “specific target energy efficiency” operation mode, the control unit 970 plans the operation of the system to generate the maximum possible amount of water while maintaining the energy efficiency in terms of Wh/L at the specified target +- x% error margin. The specified energy efficiency is calculated based on the energy consumed from turning on externally-supplied heating 952. The thermal energy collected from adsorption process in 950, ambient air heat exchanger 901, and solar heater 902 are not included in the energy calculation since those are ambient thermal energy that are harvested.

If the control unit 970 determines that it can reach the maximum possible daily generation capacity without exceeding the specified Wh/L efficiency, the control unit will attempt to achieve a better energy efficiency, i.e. lower Wh/L value.

If, given the measured and forecasted ambient conditions, the control unit determines that it is not feasible to generate any amount of water at the specified energy efficiency level, the control unit will put the system in hibernation mode; and the control unit will keep rechecking the current and forecasted ambient parameters every specified duration of time. If and when the control unit determines that the current measured and forecasted ambient parameters indicate that it is feasible to generate an amount of water at the specified energy efficiency level, the control unit turns on the system and attempts to harvest water while meeting the specified energy efficiency target.

Numerous modification and variations on the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.

Claims

Claims:

Claim i . A system configured to circulate a thermal fluid in a circulation loop connected to at least one flow control valve, the system comprising: the thermal fluid; at least one heat exchanger; the at least one flow control valve configured to redirect a flow of the thermal fluid to contact the at least one heat exchanger connected to at last one thermal element, the at least one flow control valve can be reconfigured to change a circulation of the thermal fluid to contact or bypass the at least one thermal element; the at least one thermal element selected from the group consisting of a heat- source, a heat-storage, and a heat-consuming element; and a controller configured, based on sensor measurements comprising a temperature, to set states of the at least flow control valve to configure a thermal fluid path and to control transfer of thermal energy from the at least thermal element between the at least thermal element and the thermal fluid.

Claim 2. The system of claim 1, further comprising a main circulation loop, wherein the main circulation loop is a serpentine comprising at least one segment, wherein each segment is connected to the at last one flow control valve that can optionally redirect the flow of the thermal fluid to contact or bypass the at least one thermal element in the system.

Claim 3. The system of claim 1, wherein the at least flow control valve is configured to control a circulation of the thermal fluid to contact the at least one thermal element in any order.

Claim 4. The system of claim 1, wherein the at least one thermal element comprises the at least one heat exchanger configured to harvest thermal energy from at least one source selected form the group consisting of ambient air heat, adsorption energy for gas adsorbing onto a sorbent, solar irradiation energy, waste heat generated from vacuum pump, heat generated when gas is condensed on a surface, and heat from an output gas or a liquid stream from an industrial process.

Claim 5. The system of claim 1, wherein the at least one thermal element is a heat- consuming element comprising a sorbent inside a vacuum chamber that is connected to a vacuum pump to lower pressure inside the vacuum chamber to desorb adsorbed gas molecules in the sorbent wherein: g. the sorbent is connected to the at least one heat exchanger contacting a circulating thermal fluid; h. at least one of the heat-source elements is an electric-based heater; i. based on current temperature conditions of the thermal fluid, historical, current, or forecasted temperature conditions of external environment, and/or gas partial pressure conditions inside and outside the heat-consuming element chamber, the controller is further configured to set a flowrate of the thermal fluid and/or time when the thermal fluid contacts the sorbent connected to the at least heat exchanger and when an electric-based heating is turned on to heat the thermal fluid or heat up the sorbent directly.

Claim 6. A method for circulating a thermal fluid in a circulation loop connected to at least one flow control valve, the method comprising: redirecting a flow of the thermal fluid to contact at least one heat exchanger connected to at last one thermal element using at least one flow control valve, wherein the at least one flow control valve changes a circulation of the thermal fluid to contact or bypass the at least one thermal element, wherein the at least one thermal element is selected from the group consisting of a heat-source, a heat-storage, and a heat-consuming element; and based on sensor measurements comprising a temperature, setting a state of the at least flow control valve by using a controller to configure a thermal fluid path and controlling a transfer of thermal energy from the at least thermal element between the at least thermal element and the thermal fluid.

Claim 7. The method of claim 6, wherein the circulation loop comprises a main circulation loop, wherein the main circulation loop is a serpentine comprising at least one segment, and wherein each segment is connected to the at last one flow control valve that optionally redirects the flow of the thermal fluid to contact or bypass the at least one thermal element.

Claim 8. The method of claim 6, further comprising: controlling, using the at least flow control valve, a circulation of the thermal fluid such that the thermal fluid contacts the at least one thermal element in any order.

Claim 9. The method of claim 6, wherein the at least one thermal element comprises the at least one heat exchanger which is configured to harvest thermal energy from at least one source selected from the group consisting of ambient air heat, adsorption energy for gas adsorbing onto a sorbent, solar irradiation energy, waste heat generated from vacuum pump, heat generated w'hen gas is condensed on a surface, and heat from an output gas or a liquid stream from an industrial process.

Claim 10. The method of claim 6, wherein the at least one thermal element is a heat- consuming element comprising a sorbent inside a vacuum chamber that is connected to a vacuum pump to lower pressure inside the vacuum chamber to desorb adsorbed gas molecules in the sorbent, wherein: j. the sorbent is connected to the at least one heat exchanger contacting a circulating thermal fluid; k. at least one of the heat-source elements is an electric-based heater; l. based on current temperature conditions of the thermal fluid, historical, current, or forecasted temperahire conditions of external environment, and/or gas partial pressure conditions inside and outside the heat-consuming element chamber, setting, using the controller, a flowrate of the thermal fluid and/or time when the thermal fluid contacts the sorbent connected to the at least heat exchanger and when an electric-based heating is turned on to heat the thermal fluid or heat up the sorbent directly.