Resonant thermal oscillator for improving output of thermal fluid system

Abstract

A method includes providing a resonant thermal oscillator in a thermal fluid system having at least two counter-flowing liquid streams separated by at least one spectrally absorbing material, where the spectrally absorbing material is hydrophobic, light-absorbing and photo-thermal, and adjusting a flow rate in at least one of the counter-flowing liquid streams to maximize heat transfer between the at least two counter-flowing liquid streams.

Description

[0001] This application is a divisional application of an application with a filing date of February 12, 2021, an invention name of “Resonant thermal oscillator for improving the output of thermal fluid systems”, an international application number of PCT / US202I / 017965 and a Chinese national application number of 202180014086.1.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of U.S. Provisional Application No. 62 / 975,747 filed in the United States on February 12, 2020. U.S. Provisional Application No. 62 / 975,747 and all related attachments are expressly incorporated in their entirety.

[0004] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0005] This invention was made with government support under grant number EEC-1449500 awarded by the National Science Foundation and grant number FA9550-15-1-0022 awarded by the Air Force Office of Scientific Research. The government has certain rights in this invention. This invention was also supported in part by grant number H20398 awarded by the Cari and Lillian Illig Fellowship and grant number H20803 awarded by the Texas Instrument Visiting Professorship. Background Art

[0006] With the increasing demand for fresh water availability, current water treatment methods face the major limitation of low fresh water recovery from high salt sources such as seawater, brackish water and process water due to high dissolved solids concentration, which makes filtration techniques ineffective and pressure-based methods impractical. One possible solution to the clean water crisis is off-grid solar thermal desalination technology, which is developing with modular designs combined with lightweight and cost-effective materials. These qualities make solar thermal desalination a promising method for high salinity water purification, which can be applied in areas where conventional electricity is not available. The main limitation of any evaporation-based desalination process is its inherent low thermodynamic efficiency due to its reliance on energy-consuming phase changes.

[0007] Development of this invention was supported in part by Grant Nos. C-1220 and C-1222 from the Robert A. Welch Foundation. SUMMARY OF THE INVENTION

[0009] This Summary is provided to introduce a selection of concepts that are further described below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

[0010] In one aspect, embodiments disclosed herein relate to a system comprising: a nanophotonics driven solar distillation system, a dynamic heat recovery (HX) system, at least two counter-flowing liquid streams separated by at least one spectrally absorbing material, wherein at least one of the counter-flowing liquid streams comprises a feed stream and a distillate stream, and wherein the spectrally absorbing material is hydrophobic, light absorbing, and photothermal.

[0011] In another aspect, an embodiment of the present disclosure relates to a method comprising the following steps: combining a nanophotonics driven solar distillation system and a dynamic heat recovery system into a coupled system when at least two counter-flowing liquid flows comprising a feed flow and a distillate flow separated by a spectrally absorbing material are matched, recycling thermal energy into the feed flow through the coupled system of the nanophotonics driven solar distillation system and the dynamic heat recovery system, and enabling operation through the coupled system when no light is incident on the coupled system of the nanophotonics driven solar distillation system and the dynamic heat recovery system.

[0012] In yet another aspect, embodiments disclosed herein relate to a method comprising the steps of providing a resonant thermal oscillator in a thermal fluid system having at least two counter-flowing liquid streams separated by at least one spectrally absorbing material, wherein the spectrally absorbing material is hydrophobic, light-absorbing and photothermal, and adjusting the flow rate in at least one of the counter-flowing liquid streams to maximize heat transfer between the at least two counter-flowing liquid streams.

[0013] Other aspects and advantages of the claimed subject matter will be apparent from the following description and appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic diagram of a PTFS light-powered chemical reactor is shown.

[0015] Figure 2A An example of a NESMD module and a coupled dynamic heat recovery system HX module according to one or more embodiments is shown.

[0016] Figure 2B A schematic diagram of an unfolded system is shown according to one or more embodiments.

[0017] Figure 2C Examples of flux in a TDO for different distillate flow rates according to one or more embodiments are shown.

[0018] Figure 2D Examples of power transfer in TDO for different distillate flow rates according to one or more embodiments are shown.

[0019] Figure 2E A schematic diagram of a NESMD module without an HX module is shown.

[0020] Figure 2F A schematic diagram of a NESMD module with focusing elements and without an HX module is shown.

[0021] Figure 2G A schematic diagram of a NESMD module with an HX module is shown.

[0022] Figure 2H Distillate flux rates are shown for a number of systems, including systems according to one or more embodiments.

[0023] Figure 2J Ion concentrations are shown after treatment of seawater in a system according to one or more embodiments.

[0024] Figure 2K Ion concentrations after frac water treatment in a system according to one or more embodiments are shown.

[0025] Figure 3A An example of a STREED module is shown according to one or more embodiments.

[0026] Figure 3B The flux rate and actual time-dependent illumination over a 48-hour operation of a STREED module according to one or more embodiments are shown.

[0027] Figure 3C An example of optimized feed flow rate as a function of light intensity input is shown for one embodiment of the present disclosure.

[0028] Figure 3D An example of a STREED module is shown according to one or more embodiments.

[0029] Figure 3E Examples of STREED modules in series and parallel configurations are shown according to one or more embodiments.

[0030] Figure 3F Shows a STREED system according to one or more embodiments for use in oilfield operations;

[0031] Figure 3G Shows an example of the correlation of the fixed STREED performance layer with the flux and gain output ratio (GOR).

[0032] Figure 4-6 Shows a schematic diagram of different experimental conditions in the NESMD module coupled to the HX module according to one or more embodiments.

[0033] Figure 7 Shows a two-dimensional schematic diagram of a TDO system according to one or more embodiments.

[0034] Figure 8 Shows the total heat flux vector field of the system according to one or more embodiments.

[0035] Figure 9A shows the temperature difference along the length of the HX film in the metal wire in the NESMD according to one or more embodiments.

[0036] Figure 9B shows for Q D (1 mL / min) << QF (6.5 mL / min), the purified water flux through the membrane in the NESMD according to one or more embodiments.

[0037] Figure 9C shows for Q D (7.4 cm) ~ QF (6.5 mL / min), the temperature difference in the system with and without the HX module.

[0038] Figure 9D shows for Q D (7.4 cm) ~ QF (6.5 mL / min), the flux through the membrane with and without the HX module.

[0039] Figure 9E shows for Q D (100 mL / min) >> QF (6.5 mL / min), the temperature difference with and without the HX module.

[0040] Figure 9F shows for Q D (100 mL / min) >> Q F (6.5 mL / min), the flux through the membrane with (solid line) and without (dashed line) the HX module.

[0041] Figure 10A shows a schematic diagram of the TDO system, which shows different heat loss mechanisms in two parts of the coupled system according to one or more embodiments.

[0042] 10B illustrates conduction loss, convection loss, and radiation loss and maximum output in a polycarbonate window layer and water channel according to one or more embodiments.

[0043] Fig. 10C Shown is the distillate flux from a NESMD having the same size HX module for equal feed flow rate and distillate flow rate.

[0044] Fig. 10D Best-matched flow rate values ​​and corresponding flux rates for different module sizes according to one or more embodiments are shown.

[0045] Fig.10E A schematic diagram of a stacked TDO system is shown according to one or more embodiments.

[0046] Fig.10F Shown is a comparison of flux production from NESMD with 10 HX layers during a 9-hour day with and without dynamic control.

[0047] Fig.11 The maximum temperature in the TDO system at varying resonant feed and distillate flow rates is shown for increasing NESMD size with equal length HX modules.

[0048] Fig.12 Static and dynamic resonant flow rates along with intensities are shown according to one or more embodiments.

[0049] Fig.13A The dependence of the flux rate on n (1 to 10) for different incident intensities I (0.1 to 1 Sun) is shown.

[0050] Fig. 13B The dependence of the flux rate on n (1 to 10) for different incident intensities I (0.1 to 1 Sun) is shown.

[0051] Fig. 13C The dependence of the flux rate of the layered TDO system at different solar intensities and with varying heat transfer coefficients is shown.

[0052] Fig.14A The variation of flux rate and efficiency with illumination for a single-layer TDO system is shown.

[0053] Fig. 14B The flux rate and efficiency variation with illumination for a five-layer TDO system are shown.

[0054] Fig. 14C The flux rate with illumination and the corresponding optimized feed and distillate flow variations for a ten-layer TDO system are shown.

[0055] Fig.15A The optimized feed and distillate flows in the system are shown for different intensities and losses.

[0056] Fig. 15B shows the strength and loss for the changes, Fig.15A The corresponding temperature of the system in .

[0057] FIG. 16A shows a heat source having a length and a thickness and being a heat conductor. s Separated two countercurrent flows Q F and Q D two interacting channels.

[0058] Figure 16B shows that at a fixed Q F and h eff =200W / m 2 / K, L = 24in, c = 4.18kJ / kg / K, ρ = 1g / cm 3 In the case of Q D The function of I F→D and I F→D Heat transfer enhancement (relative to I s Normalized).

[0059] FIG. 16C shows the dependence of the heat transfer flux enhancement on the matching flow rate for different module sizes.

[0060] FIG. 16D shows that for Q F =20mL / min and Q D = Calculated temperature map for 2 mL / min.

[0061] FIG. 16E shows that for Q F =20mL / min and Q D = Calculated temperature map for 200 mL / min.

[0062] FIG. 16F shows that for Q F =Q D = Calculated temperature map for 20 mL / min.

[0063] FIG. 16G shows the probe trajectory in the TDO system under different resonance conditions.

[0064] Fig.17 Shown is the flow-dependent heat transfer as a Lorentzian function with no fitting parameters

[0065] Fig.18AThe flux rates of the cascade system in dependence on incident irradiation without heat recovery, with heat recovery and at the theoretical limit of heat desalination without heat recovery are shown, as well as the extracted solar energy utilization efficiency obtained by taking the ratio between the calculated flux rate without heat recovery and the corresponding theoretical limit.

[0066] Fig.18B The GOR calculated by taking the ratio between the calculated flux rates with and without heat recovery and assuming solar efficiency is shown.

[0067] Fig.19 The heat transfer enhancement of the system from feed to distillate as a function of module lengths of 10 cm, 20 cm, 50 cm, 100 cm, 200 cm and the fitting parameter γ is shown.

[0068] Fig. 20A and 20B The analytical solution of the 1m system is shown as the loss in the system (g eff value) and equal feed flow rate and distillate flow rate as a function of the net heat transfer from feed to distillate.

[0069] Fig.21A Solar desalination using a resonant thermal oscillator with energy storage capability after several hours of treatment on a cloudy day is shown.

[0070] Fig.21B Solar desalination using a resonant thermal oscillator with energy storage after a few hours of processing on a sunny day is shown.

[0071] Fig. 22 The effect of reduced thermal conductivity of the HX material is shown.

[0072] Fig.23A Shown are the fresh water flux rate and maximum temperature in the system as the thickness (w) of the feed and distillate channels varies from -0.5 mm to -50 mm.

[0073] Fig. 23B The temperature and heat flux vector fields are shown for the case w ~ 0.5 mm.

[0074] Fig.23C The temperature and heat flux vector fields are shown for the case w ~ 1.6 mm.

[0075] Fig.23D The temperature and heat flux vector fields are shown for the case w ~ 50 mm.

[0076] Fig.24 A flow chart describing a method for a resonant thermal oscillator in a thermal fluid system according to one or more embodiments is shown. DETAILED DESCRIPTION OF THE INVENTION

[0078] The specific embodiments will now be described in detail with reference to the accompanying drawings. For consistency, like elements in the various drawings are represented by like reference numerals.

[0079] In the following detailed description of the embodiments, a large number of specific details are set forth to provide a more thorough understanding. However, it is apparent to one of ordinary skill in the art that each embodiment can be implemented without these specific details. In other cases, well-known features are not described in detail to avoid unnecessarily complicating the description.

[0080] In the following description, any component described with reference to an accompanying drawing in each embodiment of the present disclosure may be equivalent to one or more components of similar names described with reference to any other accompanying drawings. For the sake of brevity, at least a portion of these components is implicitly displayed based on different legends. In addition, the description of these components may not be repeated for each accompanying drawing. Therefore, each embodiment of each component in each accompanying drawing is incorporated by reference, and it is assumed that it is optionally present in each other accompanying drawing with one or more components of similar names. In addition, according to each embodiment of the present disclosure, any description of each component in the figure should be interpreted as an optional embodiment, which can be implemented in addition to, in combination with or in place of the embodiment described with respect to the corresponding component of similar name in any other accompanying drawing.

[0081] In this application, ordinal numbers (e.g., first, second, third, etc.) may be used as adjectives of elements (i.e., any noun in the application). Unless explicitly disclosed, such as using the terms "before," "after," "single," and other such terms, the use of ordinal numbers does not imply or cause any particular order of elements, nor does it limit any element to only a single element. Rather, the use of ordinal numbers is used to distinguish between elements. For example, a first element is different from a second element, and a first element may encompass more than one element and is after (or before) a second element in the element order, if there is an order.

[0082] The term solar energy is understood to include any source capable of emitting sunlight energy, including natural sources such as the sun, and artificial light sources such as LEDs, lasers, and nano-sized light emitters.

[0083] Embodiments of the present disclosure relate to thermal fluid systems using oscillating thermal elements. For example, embodiments of the present disclosure may include a thermal fluid system coupled to a thermal resonator, where thermal energy may be confined and recycled multiple times through a combination of heat transfer effects. The thermal fluid system may include a thermal fluid separation system based on a phase change separation method.

[0084] In some embodiments, the thermal fluid system may include a solar-driven photothermal distillation system, wherein at least a portion of the required heat of vaporization may be provided by sunlight energy. The solar-driven photothermal distillation system of the present disclosure may include a resonant heat exchanger system to achieve solar distillation of a fluid in the absence of sunlight energy.

[0085] In some embodiments, the thermal fluid system may include a desalination system with nanoparticle solar spectrum absorbing materials and a resonant heat exchange system. The resonant heat exchange system may use a thermal energy storage mechanism (also known as resonant energy exchange (REX)) to support continuous recycling of thermal energy. In some embodiments, continuous recycling of thermal energy may store the required thermal energy to operate in the absence of a solar energy source.

[0086] Embodiments of the present disclosure may include a cyclic heat transfer mechanism, wherein heat energy is captured, stored and transferred between at least two countercurrent fluid flows in a light absorption system of variable size. For example, embodiments of the present disclosure may combine a countercurrent fluid flow and a heat conductor that are heated internally in a thermal fluid system, wherein the thermal fluid system behaves like a thermal oscillator. The oscillating heat energy in the embodiments of the present disclosure may support continuous thermal processes, such as phase separation or temperature-dependent chemical reactions. In addition, operating these light absorption oscillation systems under resonant conditions may improve energy efficiency, particularly in the use of stored energy. Therefore, embodiments of the present disclosure may be characterized as thermal oscillators, because embodiments may use the properties of oscillators (such as resonance) to control temperature, improve stored energy, and be coupled in a system network. According to the present disclosure, resonance may occur when the interacting fluid flow rates are equal. The resonance in the embodiments of the present disclosure may optimize the heat exchanged, the peak temperature, and the stored heat energy.

[0087] The resonance in the thermal oscillator can maximize internal energy such as mechanical energy, electrical energy, magnetic energy and electromagnetic energy, and minimize losses. The resonant thermal element of the embodiment of the present disclosure can show large thermal inertia when resonating. This means that the system can show minimum loss and maximum response time to external stimulation. For example, if the external heat source is closed, such as a solar heat source, the system can maintain internal energy due to oscillating the internal heat flux, which prevents the loss of heat energy from the system to the environment. In addition, because different oscillators can be coupled together, the embodiment of the present disclosure can include other applications in which the thermal element is connected in a network and the spatial distribution of the temperature can be controlled by tuning the input flow rate. This possibility can be applied in the range of microfluidic devices from large-scale solar-driven systems to laser-irradiated nanoparticles embedded in microchannels that can be used as small-size heaters.

[0088] According to embodiments of the present disclosure, a thermal oscillation system can be used for a photo-thermal-fluid system (PTFS) that can be represented as a thermal resonator, in which thermal energy can be confined and recycled multiple times through a combination of heat transfer mechanisms. The PTFS can include at least two flowing fluids in a countercurrent configuration separated by at least one solar absorbing thermally conductive layer between the fluid channels. When illuminated, electromagnetic radiation can be dissipated as thermal energy in the thermally conductive layer. Heat can be transferred in antiparallel directions by the countercurrent flow, thereby generating opposite temperature gradients across the at least two fluids. The temperature difference transfers heat between the channels in a cyclic, oscillating manner. The oscillation of thermal energy in the system can minimize the loss of thermal energy through the flow outlet. This oscillation can enable the accumulation of thermal energy in at least two fluids, and the oscillation can be controlled by tuning the relative flow rate. Resonance conditions can be achieved when the flow rate is set to be equal. In some embodiments of the present disclosure, resonance conditions can be achieved by tuning a single flow rate, such as a feed flow rate, wherein fluid flow can be provided in a countercurrent configuration (e.g., by folding or looping the flow path back).

[0089] In some embodiments, resonant heat transfer can increase the reaction rate in a properly designed PTFS under both artificial and natural lighting by raising the temperature in the system. Embodiments of the present disclosure may also use resonant thermal batteries, where thermal energy is stored in the PTFS and the heat can be quickly released upon request by detuning the system flow rate from the resonant condition. Embodiments of the present disclosure may also include two PTFS with different resonant conditions that are coupled to exchange stored thermal energy. Figure 1 , a schematic diagram of a PTFS light-powered chemical reactor 100 is shown, wherein liquid phase reactants 102 (arrows) flow in opposite directions in the reactor. Artificial light 104 and natural light 106 sources are shown, which interact with a nanostructured surface 108 having a solar absorber / selective emitter 110 (shown enlarged) suitable for retaining heat and catalyzing a target chemical reaction and a reactor / photocatalyst 112 (shown enlarged). Products collected by a selectively permeable membrane 114 are shown.

[0090] In some embodiments of the present disclosure, the previously described resonant heat transfer can be coupled with solar desalination to provide storage of solar energy in the absence of a solar energy source. For example, for a system powered by the sun, desalination operations according to embodiments of the present disclosure can provide partial fresh water production overnight.

[0091] For example, experimental data from an embodiment of a desalination system enhanced using resonance in a thermal oscillator (REX) demonstrates that an oscillating thermal element increases solar thermal desalination efficiency by more than ten times compared to a non-resonant system. In such an embodiment, a coupled membrane distillation system and a heat recovery system can behave as a resonant thermal desalination oscillator (TDO), where the distillate output can be under resonant conditions. In other words, the TDO can use the REX for desalination applications. The REX system can act as a thermal battery to provide continuous thermal energy to the TDO. Tuning the feed flow and distillate flow through the TDO system as a function of light intensity can be useful for achieving an optimized oscillator, which can also depend on module size and heat losses. In an exemplary highly compact dynamic TDO system, a 500% increase in distillate flux at resonance compared to a non-resonant system was observed, demonstrated at 475 W / m 2 1.1kg / m under irradiation 2 h of fresh water production and collection. Therefore, one or more embodiments can use a dynamic input flow control that depends on intensity to keep the system optimized throughout the day's operation. One or more embodiments of the present disclosure can also utilize a more common resonance phenomenon using a simple model that is used to theoretically analyze the key principles behind resonant energy transfer. In some embodiments, the resonant system can maximize the distillate output under varying light intensities by adjusting the feed flow (e.g., by using one or more flow control devices such as valves or chokes to control the flow rate of the feed flowing into the system).

[0092] Embodiments of the present disclosure may include channels to direct fluid flows through the thermal fluid systems disclosed herein. Channels may be understood to include any structure in which fluid flows may be multi-purpose, such as a chemical reaction chamber (in which an input fluid may serve as a reactant and may be converted to a product due to an increase in temperature), a thermal storage unit (in which the accumulation and release of heat may be controlled by the input flow rate), a water purification system, or a fluid separation system (in which a temperature gradient between flows may facilitate the exchange of latent heat of vaporization between channels).

[0093] Embodiments of the present disclosure may include gaseous or liquid input and output fluids. Although some examples of thermal fluid systems disclosed herein describe aqueous solution input (e.g., brackish water or brine) for desalination, the same heat exchange concept disclosed herein can be utilized to design other fluids for different purposes together with the disclosed system. For example, various fluid types can be made to flow through thermal fluid systems disclosed herein to realize one or more chemical reactions under circulating heat conditions. In such embodiments, for example, heat exchange concepts disclosed herein can be used to accelerate certain chemical reactions. In some embodiments, various fluid types can be made to flow through thermal fluid systems disclosed herein to provide thermal oscillations between fluid streams, thereby enabling the system to be used as a thermal battery for various applications.

[0094] NESMD System

[0095] According to embodiments of the present disclosure, the PTFS may include a nanophotonics driven solar membrane distillation (NESMD) system. One or more embodiments of the present disclosure focus on the coupling between the NESMD system and the dynamic heat recovery (HX) system. Compared to conventional membrane distillation systems, the NESMD system may have a membrane that includes any porous surface having at least one reactive layer or coating, and may also be referred to as a porous surface layer. In some embodiments, the NESMD process and the HX process may be combined to recover a large amount of condensation heat from the distillate, which is reused to preheat the feed or input / inlet stream. A NESMD system coupled with an HX and operating under resonance may be an example of a REX, where REX represents the use of resonant heat transfer to intensify an application.

[0096] Figure 2A An example of NESMD modules and dynamic heat recovery system HX modules coupled in system 200 is shown. Figure 2A Channel 204 (“Feed In”) is shown through which a fluid feed from line 203 can traverse or flow. Channel 204 is connected or coupled via line 206 to channel 208 (“Feed Out”) through which the fluid feed can exit the system via line 210 . Figure 2A Also shown is a channel 212 ("Distillate In") through which distillate from line 211 can traverse or flow. Channel 212 is connected or coupled via line 214 to channel 216 ("Distillate Out") through which distillate can exit the system via line 218. Figure 2A Also shown is solar radiation 220 (curved arrows), wherein channel 208 is configured to receive solar radiation 220 . Figure 2A Also shown is a NESMD module 222 connected or coupled to channel 208 and channel 212. An air gap 224 is shown between channel 212 and channel 216. Figure 2A Also shown is a heat exchanger system, namely, HX module 226, coupled to channel 204 and channel 216.

[0097] In one or more embodiments, in its simplest form, the NESMD system can include two countercurrent streams, a brine feed and a purified distillate, separated by a hydrophobic, light-absorbing membrane. Figure 2A An example of a folded system is shown with NESMD modules 222 stacked on HX modules 226. NESMD modules and HX modules can be formed in large sizes (e.g., covering many meters of area) or small sizes (e.g., covering a few square millimeters or a few square centimeters or hundreds of square centimeters of area). In particular, the incoming brine feed (e.g., Figure 2A The "feed in" channel 204 in the embodiment of the present invention can be passed through HX (e.g., Figure 2A HX module 226 in the Figure 2A The feed is thermally contacted with the "distillate out" channel 216 in the NESMD module (e.g., Figure 2A The photothermal film present in the NESMD module 222) is further heated. Figure 2B A schematic diagram of an unfolded system with a 10.2 cm x 20.3 cm NESMD module 230 and a 10.2 cm x 40.6 cm in-line HX module 240 is shown. Figure 2C and 2D Examples of flux and power transfer in TDO for different distillate flow rates are shown according to one or more embodiments.

[0098] In some embodiments, sunlight can be converted to heat on the feed side by photothermal heating by light absorbing nanoparticles embedded in the porous surface forming the membrane. The temperature gradient induced across the membrane results in water evaporation on the feed side and condensation on the distillate side. The continuous, localized heating due to incident sunlight at the feed / membrane interface makes the NESMD size scalable and avoids temperature differentiation, overcoming two major drawbacks of conventional membrane distillation. The embodiments of the present disclosure include NESMDs that improve thermal efficiency, in part due to the increase in temperature of a micro-thin layer of water at the photothermal porous surface layer, where the water temperature is increased by the heat generated by the absorbed light.

[0099] In embodiments of the present disclosure, the nanophoton-driven membrane may be hydrophobic and allow water vapor to flow through without allowing liquids or particles to flow through. The NESMD membrane may include a hydrophobic porous surface layer and a reactive layer or coating covering the porous surface layer. For example, the NESMD membrane may include a hydrophobic porous surface layer and a reactive layer embedded with highly light-absorbing carbon black (CB) nanoparticles. The porous surface layer may be thicker than the reactive layer. For example, the hydrophobic porous surface layer may be about 100um thick, while the reactive layer may be about 2-10um thick. In some embodiments of the present disclosure, the porous surface layer may be vapor permeable but liquid water impermeable, and may be a layer close to light. In addition, in some embodiments, the porous surface layer may be a microstructured layer with a designed pore size (e.g., a pore size that allows vapor to permeate through the microstructured layer and prevents liquid from flowing through). As Figure 2A and 2B As shown, once the distillate is produced, it is brought into thermal contact with the brine feed for heat exchange. The thermal contact can be achieved by copper or aluminum sheets incorporated into the flow structure or any material with similar thermal conductivity. In fact, folding the HX module under the NESMD module avoids increasing the system footprint, which will enable a high density of NESMD modules to be arranged in a compact area.

[0100] like Figure 2E-2H As shown, the NESMD module coupled with the HX module can improve the overall efficiency of the system. Figure 2E and 2F FIG. 4 shows a schematic diagram of a NESMD module without an HX module. Figure 2F As shown, the efficiency of the NESMD module can be improved by incorporating a lens array 250 that creates thermal hot spots on the photothermal film 255. For the same input solar power, the nonlinear dependence of the saturated vapor pressure of water on temperature and light intensity can increase the water productivity by >50%. In the embodiments of the present disclosure, an in-line HX module such as Figure 2G The in-line HX module 260 in the NESMD system can further improve system efficiency by using the heat in the purified distillate to preheat the incoming brine feed. The coupling of the NESMD system with the HX module 260 is an example of the REX principle, which can increase the distillate flux rate by 500%, thereby increasing the purified water production capacity to ~20L / m2·day (see Figure 2H ).

[0101] Nanoparticle-assisted distillation of embodiments of the present disclosure can reduce ion concentrations from seawater (see Figure 2J ) and fracturing water ( Figure 2K ) produces fresh water.

[0102] As discussed above, a NESMD system may include two or more independently controlled streams, such as a feed in a flow line and a distillate in a flow line (e.g., Figure 2A 204 and "distillate out" channel 216 in FIG. 1 ). In some embodiments, the PTFS system has a single flow inlet, such as in the Solar Thermal Resonant Energy Exchange Desalination (STREED) system discussed below.

[0103] STREED System

[0104] According to embodiments of the present disclosure, the PTFS may include a STREED system. The STREED system may combine nanoparticle solar spectrum absorbing materials and a dynamic heat recovery (HX) system. In some embodiments, the nanoparticle solar spectrum absorbing materials and the HX system may be combined to recover a large amount of condensation heat from the distillate, thereby reusing the heat for preheating the feed.

[0105] Figure 3A A diagram of a desalination system 300 for desalinating saline fluid using a STREED system is shown. Figure 3A An inlet line 302 is shown, wherein a brine feed stream may flow through a brine feed channel 304 to a line 306. A light intensity dependent flow controller 308 is shown connected or coupled to the inlet line 302. A brine feed channel 304 is shown, which is coupled to a brine feed insulator 310 and a feed conductor 312. Figure 3A As shown, pipeline 306 connects brine feed channel 304 to solar brine flow channel 314. Solar insulation 316 is shown between solar brine flow channel 314 and solar energy source 318. Solar conductor 320 is shown between solar brine flow channel 314 and first vapor absorber 322.

[0106] like Figure 3A 314 and 326. As shown, a pipeline 324 is shown, which is connected to the solar brine flow channel 314 and the brine flow channel 326. The fluid can be heated by the solar energy source 318 in the solar brine flow channel 314 and then flow through the pipeline 324 to the brine flow channel 326. The brine flow channel 326 is configured to have an internal porous surface (not shown) through which the fluid can traverse from the brine flow channel flow 326 to the coupled nanoparticle mesh 328. The first vapor 330 can traverse through the nanoparticle mesh 328 and reach the first vapor absorber 322 through the first gap 332. The first vapor absorber 322 is shown, which is connected to the pipeline 334 through which the fluid collected in the first vapor absorber 322 can traverse.

[0107] The brine feed insulator 310 may be coupled to the brine flow channel 326 on an opposite side from the nanoparticle mesh 328. Thus, in the illustrated embodiment, the brine feed insulator 310 may be adjacent to and layered between the brine feed channel 304 and the brine flow channel 326 to insulate the heated brine flow channel 326 from the brine feed channel 304 (which may have a relatively cooler brine feed flowing therethrough).

[0108] exist Figure 3A 3, a line 336 is shown fluidly connected between the saline flow channel 326 and the second saline flow channel 338. The second saline flow channel 338 has an internal porous surface (not shown) through which the second vapor 340 can traverse through the second gap 344 to the second vapor absorber 342. The second vapor absorber 342 is shown fluidly connected to a line 346 through which the fluid collected in the second vapor absorber 342 can traverse. A line 348 is shown fluidly connected to the second saline flow channel 338 through which the fluid can exit the second saline flow channel 338. A second insulator 350 can be attached to or disposed on the opposite side of the second saline flow channel 338 from the second gap 344.

[0109] In embodiments of the present disclosure, at least three product streams may be produced, namely (i) a first purified water stream, (ii) a second purified water stream, and (iii) a brine waste stream. The first purified water stream may be contained in a line exiting from the first vapor absorber such as Figure 3A The second purified water stream may be contained in a line such as 334 exiting from the second vapor absorber. Figure 3A The spent brine stream can be traversed through a second brine stream channel to a pipeline exiting the system, such as Figure 3A Pipeline 348 in.

[0110] In some embodiments of the present disclosure, an ultrasonic transducer can be used to mitigate water scale. The ultrasonic transducer can be coupled to a channel (e.g., Figure 3A The ultrasonic transducer can provide regular scale and fouling removal with minimal downtime.

[0111] According to embodiments of the present disclosure, a system including a STREED module may have a length and a width in the range of about 0.5 m to 2 m, respectively, and may have a height from the top layer (e.g., Figure 3A ) to the bottom layer (e.g., Figure 3A The thickness of the second insulator 350 layer) shown in FIG.

[0112] In embodiments of the present disclosure, a saline flow channel such as Figure 3A The brine flow channel 326 in the embodiment may include at least a portion of a porous wall, wherein the porous wall may be configured to prevent the fluid from flowing through the pores while allowing vapor from the fluid to flow through the porous wall and through the gaps, such as Figure 3A In some embodiments of the present disclosure, broadband absorber nanoparticles ("nanoparticles") may be coupled to the inner surface of the brine flow channel. The nanoparticles may be applied to at least the porous wall portion of the channel. The nanoparticles may be applied to the inner surface of the brine flow channel by spraying, where the nanoparticles may be combined with the porous wall portion of the channel. In some embodiments, the nanoparticles may form a coating on a portion of the inner surface of the brine flow channel that is close to the gap separating the brine flow channel and the vapor absorber. In some embodiments of the present disclosure, the combination of the porous material and nanoparticles of the brine flow channel may be characterized as a nanoparticle mesh. In some embodiments of the present disclosure, the porous wall portion of the channel may be characterized as a mesh, wherein the mesh may be combined with the nanoparticles and support the nanoparticles during operation of STREED. In some embodiments of the present disclosure, the porous wall portion or the mesh may be flexible. The pores of the mesh may be large enough to allow water to pass through.

[0113] Nanoparticles can include broadband, light-absorbing carbon black particles. Nanoparticles can be used to localize solar energy, minimize heat losses, and minimize or eliminate the need for external energy for evaporating and separating water from a brine stream. Heat localization within the nanoparticle coating or layer can cause an increase in temperature on the inner surface of the channel and the brine contained therein. Compared to conventional membrane-based desalination systems, the nanoparticles of embodiments of the present disclosure can mitigate water rust and fouling.

[0114] In embodiments of the present disclosure, insulation layers such as solar insulation 316, brine feed insulation 310, and second insulation 350 may be composed of insulating materials such as fiberglass, cellulose, aerogel, or polymers such as polyurethane, polystyrene, or a combination of insulating materials. In some embodiments, infrared reflectors or selective emitters may be used as solar insulation to minimize radiation losses. Insulation layers may also be composed of transparent materials.

[0115] In embodiments of the present disclosure, conductors and conductive layers such as solar conductor 320 and feed conductor 312 may be made of thermally conductive materials such as metals, such as copper or aluminum.

[0116] In an embodiment of the present disclosure, the vapor absorbers, such as the first vapor absorber 322 and the second vapor absorber 342, may be made of any material, such as a hydrogel, that is capable of condensing water and has a suitable thermal conductivity.

[0117] In addition, according to embodiments of the present disclosure, the STREED system may include a REX mechanism. REX may provide embodiments with the thermal energy required to support continuous systems such as continuous desalination systems without additional energy sources. REX may store energy and drive long-term operation. The stored energy of REX may be used to continue operation during periods when solar input is unavailable, such as at night and during days covered by heavy clouds. Figure 3B As shown, integration of a REX may enable embodiments of the present disclosure, such as a STREED module, to operate after solar energy is unavailable.

[0118] In embodiments of the present disclosure (e.g., in the NESMD system and the STREED system), REX can be implemented by tuning the brine feed flow rate with the solar intensity input. In this way, continuous operation can be ensured by optimizing the input conditions. Figure 3C An example of feed flow rate optimized with light intensity according to one embodiment of the present disclosure is shown. More specifically, Figure 3C Data from a STREED embodiment of the present disclosure is shown, where the feed flow rate increases with increasing light intensity. The flux rate of the STREED module over a 48 hour operation can continue even at night in the absence of sun or solar energy.

[0119] In embodiments of the present disclosure, solar energy can be used to heat brine. Solar energy can provide the required heat of vaporization to separate water from dissolved solids in brine without an additional energy source. Compared to conventional membrane-based desalination processes, this type of solar-driven desalination by distillation can be used to desalinate feed water with high salinity.

[0120] In embodiments of the present disclosure (including embodiments using a STREED system or a NESMD system or both), the brine feed may be heated by heat from a purified water stream. For example, the brine feed may be heated by recirculating heat from a heated purified water stream, where the heat may be transversely transferred through conductors (e.g., Figure 3A The heat conducted to the brine feed stream through the conductors can raise the temperature of the brine feed stream to produce a heated brine stream.

[0121] In embodiments having a STREED system, a brine feed stream may enter a channel configured to receive solar energy from a solar insulator (e.g., Figure 3A The temperature of the brine feed stream in the channel can be raised by solar energy radiated through the solar insulation to produce a heated brine stream. The solar insulation can be, for example, a transparent insulation window with an emission suppression coating to minimize heat loss to the surrounding environment. The heated brine stream can also be connected to a conductor such as Figure 3A The conductor may be a transparent conductive layer configured with grooves to increase the surface area in contact with the heated brine flow, thereby improving the heat transfer efficiency. The conductor may also be coupled to a vapor absorber layer such as a first vapor absorber 322. The vapor absorber may condense water vapor. The condensed water vapor or purified water flow may flow in a direction opposite to the flow of the brine flow. The countercurrent flow of the brine flow and the condensed water vapor may provide an efficient transfer of vaporization enthalpy through the conductor to the incoming brine flow, thereby facilitating the transfer of heat from the vapor absorber to the exit pipeline (e.g., Figure 3A Efficient heat recovery of the exiting condensed water vapor in line 334).

[0122] In embodiments of the present disclosure, the heated saltwater stream may enter a channel coupled to the photothermal nanoparticle network. The heated saltwater stream may also be isolated on at least one side of the stream (e.g., Figure 3A The solar energy can radiate through the solar insulator and reach the photothermal nanoparticle mesh. The solar energy can illuminate the photothermal nanoparticle mesh, and the illuminated nanoparticles can heat the adjacent flowing fluid by light localization. When the localized heat in the nanoparticles heats the brine flow in contact with the photothermal nanoparticle mesh, the water contained therein can evaporate through the mesh. The water vapor can then pass through the gap (e.g., Figure 3A The first gap 332 in the vapor absorber) where it can be condensed into purified water in the vapor absorber. The condensed purified water can traverse through the vapor absorber to an outlet line such as Figure 3A 334 in line. As previously described, the purified water stream may transfer heat to the incoming brine feed via a solar conductor.

[0123] In some embodiments of the present disclosure, after the saline flow passes through the nanoparticle mesh layer, the fluid can flow through a second saline flow channel, such as Figure 3A The second brine flow channel 338 in the second brine flow channel. The additional stored heat in the brine flow contained in the second brine flow channel can generate additional water vapor. The additional water vapor from the second brine flow channel can pass through the porous portion of the second brine flow channel. The additional water vapor can then move across the second gap, such as Figure 3AThe second gap 344 in the middle. The additional water vapor can be absorbed by a second vapor absorber such as Figure 3A The captured water vapor can be condensed into a second purified water stream and traversed through an outlet line such as Figure 3A The second condensed water flow in the second vapor absorber can transfer heat to the brine feed channel through a conductor coupled to the second water vapor and brine feed channel. The remaining fluid in the second brine flow channel can move through an outlet line, such as Figure 3A The remaining fluid may be a brine waste stream in which the brine concentration is greater than the brine concentration in the brine feed stream. The remaining fluid may also contain thermal energy that can be used in subsequent series coupled systems.

[0124] Embodiments of the present disclosure may include a PTFS system (e.g., a STREED system and / or a NESMD system) having a flow controller coupled to a brine feed that is dependent on light intensity, wherein the flow in the brine feed line can be controlled. The input flow rate can be controlled with input light intensity, thereby providing an embodiment that achieves REX conditions. Systems in REX conditions can store energy and operate for long periods of time, particularly when solar energy is not available. REX can be implemented by tuning the feed flow rate with solar energy intensity to continuously operate under optimized conditions (see Figure 3B ).

[0125] Embodiments of the present disclosure may include PTFS systems (e.g., STREED systems and / or NESMD systems) assembled in independent modular arrangements. The modular arrangements of embodiments of the present disclosure may provide scalability of multiple modules connected or coupled together in a single operation. In this way, it is contemplated that the use of at least two modules in a single operation may meet the needs of both small and large capacities of the overall operation, depending on the number of modules used in the operation.

[0126] For example, Figure 3D An example of a single STREED module is shown, which may have a width and length in the range of, for example, about 0.5 to 2 meters and a thickness in the range of, for example, about 10 to 50 cm. Each STREED module may include at least one input stream ("brine feed in") and at least two output streams ("brine feed out" and "purified water").

[0127] Reference Figure 3E , Figure 3E A schematic diagram of several STREED modules 360 (represented by black rectangles) combined in a STREED operation 362 is shown. Figure 3E A saltwater input feed 364, a brine output 366, and a freshwater output 368 are shown. Figure 3E shows STREED modules connected in series (such as Figure 3E ), where the brine exit fluid can be used as the brine feed fluid in subsequent modules and the final brine output 366 can be combined. Figure 3E Also shown are STREED modules connected in parallel (such as Figure 3E ), where each system can operate independently of the modules in the same column and the freshwater output 364 can be combined. Figure 3E As shown, both parallel and series connections between multiple STREED modules, such as STREED module 360, can increase capacity ("y-axis"). STREED modules connected in series can also improve control of the salinity of the output stream ("x-axis"), because the output of one module can be the input of a subsequent module (see Figure 3E Module 360 ​​in the same row in FIG. 1 ). In some embodiments, and as Figure 3E As shown, the system may include a series connection ( Figure 3E row) and parallel connection ( Figure 3E For example, a system according to one or more embodiments may have N STREED modules. s =63 (where N s is the number of modules connected in series in each module row) and N p =47 (where N p is the number of modules connected in parallel in each module column) to provide a total of 2,961 modules (N p *N s ). This system with 2,961 modules connected in series and parallel has a light intensity of 6KWh / m 2 / day and the brine input feed is 120m 3 100m / day can be produced 3 / day of fresh water and 20m 3 / day of brine.

[0128] In some embodiments of the present disclosure, the use of multiple modules or units also provides improved thermal efficiency in the overall operation. Multiple layered PTFS modules such as STREED modules or NESMD modules can be stacked to improve heat recovery from the exiting brine stream. The brine waste stream from the upstream module can be fed into the downstream or lower module, where the brine waste stream can be used as the brine feed for the lower module. The same procedure can be repeated for subsequent modules, using each brine waste stream as the feed stream for the next module connected in the system, thereby minimizing heat losses to the environment. In some embodiments, the feed flowing into the lower module will absorb the heat of vaporization from the condensing steam through the (feed) conductor and continue as described.

[0129] The module arrangement of the embodiments of the present disclosure can further support thermal energy storage. Energy efficiency can be improved with each additional module because the total thermal energy continues to be recycled within the connected modules. The thermal energy is transferred to the subsequent downstream modules.

[0130] The scalable nature of the disclosed embodiments can provide desalination for large operations such as solar desalination farms and oil and gas wastewater treatment as well as small operations such as household or remote community freshwater supply. Several modules can be connected in series or parallel to achieve the desired total system capacity. The series configuration can also provide control over the salinity of the output brine (brine waste stream) when using the brine waste stream as the incoming brine feed stream for subsequent modules. Figure 3F An example of the use of a STREED system is shown in , where the STREED system may include a plurality of STREED modules connected together in series and / or in parallel. Figure 3F A STREED system is shown used in an oilfield operation, where water produced in oil extraction is preheated and fed into the STREED system. Water produced by desalination can be used for reinjection or other possible uses depending on the quality and location of the operation. In summary, the STREED implementation can reduce costs by recycling a portion of the produced water, reduce the amount of brine waste, and increase profits by selling purified water.

[0131] Embodiments of the present disclosure can be integrated into various applications, including brackish water purification for domestic, commercial and industrial operations. The availability of artificial solar light sources such as high-intensity light sources (LEDs and LASERS) and access to natural light opens up opportunities to obtain embodiments of the present disclosure from micron-nano-sized photothermal devices to large-scale thermal equipment. Examples of applications in which embodiments of the present disclosure can be used are desalination of seawater, wastewater from enhanced oil recovery operations, brine concentration, and applications with zero liquid discharge (ZLD) systems used in wastewater treatment processes.

[0132] The STREED system disclosed herein exemplifies the basic aspects of nanophotonic driven solar film desalination of the present disclosure. For example, by incorporating an optimal light focusing element and using REX to provide about ~20 L / m 2 / day of freshwater production, STREED has been shown to improve system performance. Validated theoretical modeling of the STREED module predicts that during a typical day with sunlight delivering a total of ~8kWh / m2 over 24 hours, freshwater production rates of ~30L / m 2 This performance corresponds to ~270 kWh / m 3 Or a specific energy consumption (SEC) of ~3.7 L / kWh. Under the same conditions, without using the resonant energy storage principle of the present disclosure, an evaporation system with 100% efficiency can achieve about 12 L / m 2 / sky.

[0133] STREED modules can provide desalination and thermal energy storage. 太阳 Assuming the vaporization enthalpy And I 太阳 =1kW / m 2 , the maximum evaporation flux rate per unit area of ​​a thermal desalination system without heat recovery F 太阳 It can be estimated as Although H 汽化 The actual temperature is dependent, but this number represents a baseline that can be used to evaluate system performance. Considering typical daily sunlight exposure (e.g. Figure 3B In direct sunlight, an ideal distillation system (100% thermal efficiency) without heat recovery can only achieve a maximum total daily production of fresh water. Implementations including one or more STREED modules can achieve up to A 250% increase. In addition, due to the incorporation of the REX principle in the system design, at sunset the flux rate can be reduced more slowly until the following sunrise. This aspect enables the use of the STREED module as both a desalination device and a thermal energy storage device.

[0134] Figure 3B Shown are the flux rate (left axis) of the STREED module (blue) and data on illuminance (right axis) from the actual time-dependent illuminance (green) over a 48 hour run. Figure 3C An example of input flow rate with light intensity optimization for a STREED module is shown. Figure 3G An example of the dependence of fixed STREED performance layers on flux and gain output ratio (GOR) is shown. Figure 3B , 3CIn 3G and 3G, the data assumes an air background, where each layer in the STREED module is 0.5m long and 10cm wide. Figure 3B , 3C The materials and corresponding thicknesses used in the STREED modules of 3G and 10G include the following: 1 cm thick acrylic glass insulator, 0.5 mm ITO conductor, 5 mm air gap evaporated layer, 100 μm nanoparticle layer, and 2 mm feed water channel. The suppressed emissivity (ε = 0.1) and convection (h c =0.5W / (m 2 K)).

[0135] Embodiments of the present disclosure can be used to improve the performance of thermochemical reactors. For example, a thermal fluid system according to an embodiment of the present disclosure can be used as a thermochemical reactor, wherein at least two liquid streams of countercurrent flow contain at least one chemical precursor for a chemical reaction in a resonant thermal oscillator. In some embodiments, a catalyst material can be arranged along at least one surface in the system (for example, on a heat absorbing layer), which can be used for one or more reactions in a catalytic system. Heat exchange in a thermal fluid system as a thermochemical reactor according to an embodiment of the present disclosure can be used to change the rate of chemical reactions in the thermal fluid system. For example, by controlling the flow rate of one or more fluid streams flowing through the system, heat exchange can be optimized to provide a selected temperature condition for reaction, thereby controlling the rate of chemical reaction.

[0136] Embodiments of the present disclosure can provide cost-effective desalination of water supplies with minimal maintenance requirements. Embodiments of the present disclosure can also provide fresh water supplies to remote locations. For example, STREED modules can integrate solar energy absorption and water desalination without solar concentrators while being able to handle a wide range of salinities.

[0137] Embodiments of the present disclosure may also reduce wastewater disposal costs, transportation emissions, and wastewater injection environmental risks by reducing water disposal volumes.

[0138] Experimental setup

[0139] Experiments were conducted using a 10.2 cm x 20.3 cm NESMD module with a 10.2 cm x 40.6 cm in-line HX and 2 mm water channels on both sides. In order to study the effect of heat transfer in achieving resonant conditions for the system, variations in external parameters such as incident light intensity and temperature were minimized. Therefore, an LED lamp (FAISHILAN 200 W LED floodlight, 1000 W halogen equivalent outdoor work light, IP66 waterproof type with US-3 plug and switch, 20000 Lm, 6500 K) was used to generate ~475 W / m 2The NESMD is irradiated at a distance of an intensity of . In some embodiments, a water bath (SoCal Biomed) is used to keep the input temperature of the feed and distillate equal and constant at 25°C. This water bath temperature is referred to as the ambient temperature. The external temperature is ~20°C. In all theoretical modeling, the input ambient temperature of the feed and distillate is set to 25°C, and the external radiator temperature is set to 20°C. A variable speed peristaltic pump (Cole-Parmer peristaltic pump; 0.4 to 85mL / min, 12VDC / 115VAC UX-73160-32) is used to circulate 1 wt% brine feed and deionized distillate at the top and bottom of the membrane, respectively. The light absorbing membrane installed in the NESMD unit is made by spraying a polyvinylidene fluoride (PVDF) membrane with a light absorbing layer of carbon black (Cabot Corporation) nanoparticles. The 10.2cm×40.6cm heat exchanger includes a ~500μm thick aluminum sheet for heat exchange. The experimental setup used a lower 1% (10,000 TDS) salinity input feed water.However, in some embodiments, large solute content in the feed channel can have a sensitive impact on flow rate optimization and should be considered to maximize heat recovery.

[0140] Thermal desalination oscillator performance

[0141] Steering Figure 2C , Figure 2C The calculated flux through a 10.2 cm × 20.3 cm NESMD with (blue curve) and without (magenta curve) HX within the 10.2 cm × 40.6 cm line is shown for different distillate flow rates at a fixed feed rate of 6.5 mL / min. The uncertainty arises from the variation in CB thickness (2-10 μm). The measured experimental flux for the coupled system with HX is shown as blue diamonds and without HX as magenta triangles. In some embodiments, as Figure 2C As shown, keeping the feed flow rate (QF) constant at 6.5 mL / min, a clear resonant behavior can be observed by changing the distillate flow rate, achieving a resonant flow rate of ~1.1 kg / (m 2 h) of the maximum purified water flux. Figure 4-6 The blue shaded area corresponds to the simulated purified water flux for these experimental conditions, shown in more detail in FIG. 2. The width of the simulated curve reflects the variation in the penetration depth of the CB coating (2-10 microns). Figure 2C Also shown in FIG. 5 is the calculated (magenta shaded area) flux for the bare NESMD system.

[0142] Steering Figure 2D , Figure 2D Shown for Figure 2CThe power transferred from the distillate to the feed in the HX region is calculated for the device in FIG. In a coupled system, when the distillate flow rate is much faster than the feed (Q D > > Q F ) or much slower (Q D < F ), the distillate flux is significantly lower than the flux under resonant conditions. In some embodiments, the calculated power transferred from the distillate to the feed appears at a peak at matched feed rate and distillate rate. Figure 7 A two-dimensional schematic diagram of the TDO system is shown, where water is represented by the blue region, HX is represented by orange, and the light absorbing film is represented by grey.

[0143] Figure 8 The results show that the feed rate was 6.5 mL / min and (i) 1 mL / min (Q D < F )、(ii)7.4mL / min(Q D ~Q F ) and (iii) 100 mL / min (Q D >>Q F Total heat flux vector field in the TDO system (arrows - blue: NESMD, and green: HX) at distillate flow rates of 20 ℃ and 10 ℃ respectively. The three schemes result in very different heat flux and temperature distributions. D ~Q F The resonance condition of Figure 8 A clear cyclic heat flux appears in (ii). A more detailed analysis is shown in Figures 9A-9F.

[0144] Turning to FIGS. 9A-9F , FIG. 9A-9F illustrate temperature and flux analysis of NESMD with and without HX according to one or more embodiments. FIG. 9A illustrates the temperature difference along the length of the HX and the metal in the 10.2 cm×20.3 cm membrane within the 10.2 cm×40.6 cm line in the NESMD, which is obtained by subtracting the distillate temperature from the feed temperature (solid line). For the case without HX (dashed line), the metal in the HX is replaced by an insulator with no thermal conductivity (~10-9 W / (m·K)). The Q is shown. D (1mL / min)< F Figure 9B shows the graph for Q D (1mL / min)< F (6.5 mL / min), purified water flux through the membrane in NESMD with (solid line) and without (dashed line) HX. FIG9C shows the flux of purified water through the membrane in NESMD with (solid line) and without (dashed line) HX. D (7.4cm)~Q F ​​​​(6.5 mL / min), the temperature difference with (solid line) and without HX (dashed line). FIG9D shows the temperature difference for Q D (7.4cm)~Q F (6.5 mL / min), the flux through the membrane with (solid line) and without (dashed line) HX. FIG9E shows the flux through the membrane with (solid line) and without (dashed line) HX. D (100mL / min)>>Q F (6.5 mL / min), the temperature difference with (solid line) and without HX (dashed line). FIG9F shows the temperature difference for Q D (100mL / min)>>Q F (6.5 mL / min), flux through the membrane with (solid line) and without (dashed line) the HX module.

[0145] In some embodiments, for Q D < F ( Figure 8 (i) and 9A-9F), the feed receives heat from the membrane, but loses this heat rapidly through its outlet. The maximum temperature difference occurs at the feed outlet, where the incoming distillate temperature is close to 25°C. In the rest of the device, as shown in Figure 9A, the slow distillate receives heat from the countercurrent feed, resulting in a slightly negative temperature difference. As shown in Figure 9B, ΔT(x) results in 'back evaporation', that is, evaporation from the distillate to the feed. This can explain why Figure 8 The blue energy flux arrows in the NESMD region in (i) point from the distillate to the feed. D ~Q F , the feed first increases its temperature along x, absorbing heat from the distillate by conduction. As shown in Figures 9C and 9D, in the membrane region with positive ΔT(x), heat is transferred to the distillate by water evaporation.

[0146] The hot distillate leaving the membrane zone exchanges heat with the feed and its temperature is reduced. Figure 8 This process is maximized when heat begins to circulate in the system, as shown by the flux arrows in (ii). In some embodiments, heat is cycled back and forth between the feed and the distillate, and this resonance effect is responsible for the dramatically increased water flux. D >>Q F , the slower feed receives more heat from the light absorbing layer. As shown in Figures 9E and 9F, the faster distillate reduces the interaction time between the feed and distillate, maintaining an overall positive temperature gradient across the membrane. Figure 8 ​This results in a heat flow from the feed to the distillate in the form of a purified water flux, as shown in FIG. 8(iii). Although the distillate collects heat by condensation, the short interaction time limits the heat exchange and heat is lost as the distillate leaves the HX (FIG. 8(iii), green arrows).

[0147] In some embodiments, when the flow rates are matched (resonance condition), the stored energy and its decay time are maximized because the total losses are minimized (which is characteristic of a vibrating system at resonance). Figure 8 (ii) shows that this effect is due to the heat flux alternating (oscillating) between the feed and the distillate. Figures 9A-9F show in detail how the energy decay time can be calculated analytically for a simplified but substantially equivalent case, highlighting the similarities to the more common time-driven harmonic oscillator.

[0148] Dynamic heat recovery as a function of system size, losses and intensity

[0149] In some embodiments, the performance of the NESMD and / or STREED system is predicted to improve as the module size increases. For example, Figures 10A-10F show data related to an example of enhanced purified water production for a TDO system as the size increases. Figure 10A shows a schematic diagram of a TDO system showing different heat loss mechanisms in two parts of a coupled system with equal membrane length and conductor length. Figure 10B shows the performance of the NESMD and / or STREED system at 20°C under 1 Sun illumination (1 kW / m 2 ) normalized to input solar power in the polycarbonate window layer and water channels in a 10.3 cm × 50 cm NESMD module connected to a 10.3 cm × 50 cm HX module. The normalized distillate flux is shown in blue. The relevant loss mechanisms are convection and conduction through the feed and distillate water flows, conduction through the polycarbonate (PC) window to the environment, and convection / radiation from the top PC surface. The relative weight of each loss channel normalized to input solar power is shown in FIG10B as a function of flow rate.

[0150] Fig. 10C The distillate flux from a 10.3 cm wide NESMD module with the same size heat exchanger module having a length ranging from 10 cm to 200 cm for equal feed and distillate flow rates is shown. Fig. 10C The dependence of the flux rate on the feed flow rate and the distillate flow rate is shown in FIG. The dotted line marks the flux when the maximum temperature in the system is above the boiling point of water. Fig.11 As shown, the dashed curve corresponds to the maximum temperature (T max ) is higher than the boiling point of water (T B ). Fig.11The maximum temperature in the TDO system at different resonant feed and distillate flow rates is shown for increasing the NESMD module size from 10 cm to 200 cm with equal length of the lower HX layer. max ) is higher than the boiling point of water (T B ) will not work, but they are helpful to include here as they provide context for understanding system optimization. Fig. 10C Two main features observed in the curves are that (i) for a given pair of matched feed and distillate flow rates, each curve exhibits a flux peak, and (ii) the peak flux value increases with size until a certain length (~50 cm), then decreases at ~1.5 kg / m 2 h saturation.

[0151] like Fig. 10C As shown, the flux rate increases from its low value at lower flow rates because all three loss mechanisms in the PC, conduction, convection, and radiation, decrease with increasing feed flow rate. This is illustrated in FIG. 10B , which shows the relative losses from the NESMD area normalized to the input heat source from absorbed sunlight. At higher flow rates, the dominant losses are convection, primarily of the feed and distillate themselves. For a flow rate of ~20 mL / min and a module length of ~50 cm, an optimal balance between external losses and heat recirculation occurs, corresponding to ~1.5 kg / (m 2 h) Maximum freshwater flux rate ( Fig. 10C ). Although the resonant oscillator behavior can be optimized at the expense of size, the possibility to maximize the freshwater flux in a module of limited size could enable portable or modular systems with unprecedented performance and efficiency, e.g. for distributed domestic environments.

[0152] Fig. 10D The best-fit flow rate values ​​(left y-axis, black) and the corresponding flux rates (right y-axis, blue) for different module sizes are shown. Fig.10E A schematic diagram of a stacked TDO system is shown. Fig.10F A comparison of flux production (left axis) from a NESMD with 10 HX layers during a 9-hour day with dynamic control (orange) and without dynamic control (grey) is shown. Flux rates for the same system without HX layers with dynamic control (red) and without dynamic control (dark grey). Solar intensity variation (right axis) in green.

[0153] The saturation value of the distillate flux rate as the system size increases depends on the balance between the accumulated heat energy, the flow velocity and the external losses. More extended modules benefit from a larger light absorption area, but require faster flow rates and longer heat exchangers. Fig. 10D Different system sizes are shown in Fig. 10C ). The matched flow rate may increase with system size because additional convection cooling is used to avoid boiling and maintain an optimal temperature distribution to maximize flux.

[0154] To maintain resonance and optimal distillate flux values, the flow rate can be tuned dramatically as the solar radiation varies during a typical day. Consider a 50 cm isolated NESMD system with limited radiation losses (with a low emissivity coating of ∈ = 0.01 in the infrared region). The idea is to configure an efficient, folded and stacked structure with n HX layers ( Fig.10E For example, for a typical solar intensity of ( Fig.10F The green dashed curve in Figure 1 analyzes the TDO performance of using n=10 HX layers during the entire day. For each input light intensity, Fig.12 As shown, the best pair of matching flow rates is selected to obtain the best water production ( Fig.10F In some embodiments, Fig.10F The water flux produced when the flow rate varies dynamically with intensity (orange) is compared to the flux from a device with a flow value optimized for 1 Sun (grey). By integrating the flux rate over the entire day, the water flux produced when the flow rate is dynamically varied with intensity (orange) is compared to the flux from a device with a flow value optimized for 1 Sun (grey). 2 Day) compared to dynamic flow rate control can produce 20.5L / (m 2 The output from the NESMD system without HX would be much smaller: 1.7 L / (m2) with dynamic flow control. 2 ·day), and 1.5 L / (m 2 day). The specific energy consumption of the dynamic heat recovery system (i.e. the energy consumed to produce 1 cubic meter of purified water) is 276.8 kWh.

[0155] Figures 13A-13B , for different incident intensities I (0.1 to 1 Sun), the dependence of the flux rate on n (1 to 10) is shown. Fig. 13C It shows that the heat transfer coefficient h HX From 0.01-5W / m 2 When K changes, at 100W / m 2(gray), 250W / m2(red), 500W / m 2 (blue), 750W / m 2 (magenta) and 1000W / m 2 Flux generation from a 1-layer (dashed line) and 10-layer (solid line) TDO system at different solar intensities (black). For a given n, the flux rate increases with intensity because more power is harvested by the light-absorbing nanoparticles. The flux also increases with increasing n because the distillate can transfer more heat back to the feed through the longer path length provided by more HX layers. To achieve greater flux at higher intensities, the matching flow rate needs to be increased to keep the temperature below the boiling point of water. Figures 14A-14C As shown, although higher intensities give higher fluxes, above a certain intensity the efficiency begins to drop. The reason is subtle: for a given intensity, a typical flux vs. matched flow curve has Fig. 10C Shapes of the type shown are characterized by peak flow rates and lower performance for larger or smaller flows. However, T max <T B The limit will be T max ~T B The edge is pushed away from the peak, into a higher region of matching flow. This translates into less than optimal efficiency.

[0156] In some embodiments, the optimum efficiency condition also depends on the losses. Assuming a small overall heat transfer coefficient h HX =0.01W / (m 2 K), because the HX module is not exposed to the environment and can be adequately isolated. In some embodiments, the impact of HX loss on system performance is analyzed. Figures 15A-15B As shown, dynamic flow rate control can also be applied to mitigate losses. Fig.15A The data shows that the optimized feed flow and distillate flow in the system can be increased as the losses increase for the lower intensity case and decreased as the losses increase for the higher intensity case. Fig. 15B The corresponding temperatures for the same system at different intensities and losses are shown. In some embodiments, real-time dynamic flow control can take into account changing feed salinity and reduced / increased feed / distillate flow rates (due to the transfer of evaporated water between the two channels) to ensure even more accurate heat recovery optimization.

[0157] Theoretical analysis of transresonant heat flux dynamics

[0158] Turning to Figures 16A-16F, Figures 16A-16F show data from the resonant heat transfer (REX) concept according to one or more embodiments. Figure 16A shows two interacting channels with length L and thickness w. Two counter-current flows QF and Q D Also used as a planar heat source I s (W / m 2 ) are separated by a heat conductor. The flow is achieved by advection of heat along x and along z with an effective heat transfer coefficient h eff (W / m 2 The net heat transfer coefficient is calculated in the region [0-L / 2] and [-L / 2-0] respectively. F→D and I D→F The system is assumed to be thermally insulated. Heat leaves the system through the outlet. The density and specific heat of the stream (water) are ρ and c, respectively. The red arrows indicate the heat flow close to the resonant condition.

[0159] Figure 16B shows that at a fixed Q F and h eff =200W / m 2 / K, L = 24in, c = 4.18kJ / kg / K, ρ = 1g / cm 3 For the case of Q D The function of I F→D (solid line, blue) and I F→D (solid line, green) heat transfer enhancement (relative to I s Normalized). For a cross section with thickness w = 2 mm and width d = 4 in, the flow rate Q F The horizontal dashed line is I / I s =1. Figure 3C I is shown as a function of uuDD = uuDD for different system lengths of 10 cm, 20 cm, 50 cm, 100 cm and 200 cm. F→D Heat transfer enhancement (relative to I s Figure 16D shows the F =20mL / min and Q D = 2 mL / min calculated temperature map (color). The black curve is the space-time trajectory of the massless probe inserted at (0,0) until it leaves one of the channels. FIG16E shows the same content as FIG16D, but Q F =20mL / min and Q D =200 mL / min. FIG. 16F shows the same content as FIG. 16D and 16E, wherein Q F =Q D =20mL / min.

[0160] In some embodiments, a simple model may include two adjacent channels of length L and thickness w, feed (F) and distillate (D), separated by a thin thermal conductor and at a temperature T amb After entering the system, it flows in countercurrent mode (Figure 16A). In the embodiment shown, water in channels F and D flows at rates QF = Au, respectively. F and QD=Au D flow, where u F and u D represents the velocity, and A represents the cross-sectional area. The water density is ρ, and the heat capacity is c. Both flows are isolated from the environment, and the constant heat source I s (W / m 2 ) is located between the channels. F and D can be expressed with an effective heat transfer coefficient h eff Heat Exchange (along z). Phase changes in the fluid are not considered, and all parameters are assumed to be temperature independent. In addition, in some embodiments it is assumed that the flow carries heat (advection of heat), neglecting conductive heat transfer parallel to the flow direction. This assumption is reasonable in the case of large Peclet (Pe) numbers (in this embodiment, Pe>>1). Heat can leave the system through the outlets of F and D. These assumptions make it possible to characterize the interaction between F and D as two coupled 1D systems that can be solved analytically.

[0161] FIG. 16B shows that for different u F Values ​​and dimensionless parameters Relative to the input heat source I s Normalized Figure I F→D (blue line) and I D→FF (green line), the dimensionless parameter includes all system parameters and can be changed by changing u D Simple adjustment. When I F→D ≈I D→F Case of γ D ≈γ F (i.e. u D ≈u F ), the peak of heat transfer is reached. Here, heat can be recycled between F and D (Figure 16A), resulting in the accumulation of thermal energy. In mathematical terms, when u D →u F When , the system becomes 180° rotationally symmetrical about the xz plane, and the heat fluxes are definitely equal in magnitude and opposite in direction. D >>γ F or γ D <<γ B), the curves do not overlap due to the lack of mirror symmetry about z (the flow velocities have opposite signs). In simple physics terms, it can also be understood that if γ D <<γ F , the distillate flow is much faster than the feed flow, and the entire D channel is close to Tamb. Therefore, I F→D is positive, and I D→F is negative, and when γ D >>γ F , heat transfer reverses.

[0162] The flow-dependent heat transfer Described as a Lorentzian function curve with no fitting parameters (such as Fig.17 ). The Lorentz function response is representative of many oscillatory phenomena and reinforces the description of the coupled system as a system with resonances. The overlap is exactly in γ D =γ F ,in:

[0163] where γ = γ D =γ F (i.e. u D =u F )

[0164] This phenomenon has similarities to many other resonant oscillator systems (e.g., laser cavities, plasma nanoparticles, ring resonators) where an external source couples to a system that stores energy (e.g., electromagnetic energy) before the input power is released or dissipated (e.g., scattered radiation or heat) (e.g., light incident on a metal nanoparticle). In some embodiments, the system (one of the channels) is driven by a flow rate (the opposite heated channel), the stored energy is thermal energy, and the power coupled and released is a heat flux.

[0165] In addition to establishing the resonant condition, γ acts as an 'enhancement' of heat transfer between channels (I / I s ). In the case of γ∝Lu / , longer channels (larger L) will achieve stronger coupling of high-speed flows. This profile is related to the details of the TDO system, where I s represents the heat generated by the CB nanoparticles, and I F→D ,I D→F denote the evaporation-condensation and recovery heat fluxes, respectively. Translated into thermal desalination efficiency Among them I evap =H evap F, H evap (J / kg) is the enthalpy of water vaporization, and FF (kg / (m 2h)) represents the flux rate of the distillation. An efficiency greater than one can be related to the gain output ratio (GOR), which quantifies how the heat of condensation is reused for additional distillation. Considering the flux rates obtained with and without HX, for Figure 2B-2D , 7 and 8, it is possible to estimate a GOR of 5, and for n = 10 stacked structures ( Fig.18A and 18B As shown), the maximum GOR can be estimated to be ~12. Fig.18A The flux rate (left y-axis) is shown for a system with n=10 stacks in dependence on incident irradiance without heat recovery (blue, dashed line), heat recovery (blue, solid line) and the theoretical limit of heat desalination without heat recovery (as shown in Figure 2). Fig.10E and 10F ), and the extracted solar energy utilization efficiency (black, solid line) obtained by taking the ratio between the calculated flux rate without heat recovery (blue, dashed line) and the corresponding theoretical limit (right y-axis). Fig.18B The GOR (red, solid line) calculated by taking the ratio between the flux rates with heat recovery (blue, solid line) and without heat recovery (blue, dashed line) and assuming solar efficiency is shown. Dynamic control also ensures a large GOR>8 for all sunlight intensities typically obtained during the day.

[0166] The analytical model can be extended to explain the Fig. 10C The peaks shown represent the effects of the losses. The model now assumes matching flows (u D =u F ) and effective loss coefficient g eff , such as Fig.19 and 20A and transfers heat to the environment as shown in FIG. 20B. Fig.19 The heat transfer enhancement of the net heat transfer from feed to distillate (relative to I) for the system is shown as a function of module lengths of 10 cm, 20 cm, 50 cm, 100 cm, 200 cm and the fitting parameter γ. s Normalized). Fig. 20A and 20B The analytical solution of the 1m system is shown as the loss in the system (g eff The heat transfer enhancement (relative to I) from the feed to the distillate as a function of equal feed flow rate and distillate flow rate s Normalized). Figure 16C shows the correlation between the heat transfer flux improvement and the matching flow rate under different module sizes. Fig. 10C ), there is a maximum heat transfer for a specific matching flow value, and such a value depends on the channel length ( Fig. 10D ).

[0167] To visualize the oscillatory behavior of the coupled channels, in some embodiments, a 2D numerical simulation is performed on the system in FIG. 16A , where the heated flow is considered laminar and coupled to the heat transport. In FIGS. 16D-16F , the distance from resonance ( FIG. 16D : Q F / QD=10, FIG16E :Q F / QD=0.1) and near resonance (Fig. 16F: Q F Figure 16 shows a temperature map of the coupled FF and D channels for a system with 100 % FF and 100 % D channels (color, normalized to the maximum temperature in each case) with 100 % FF and 100 % D channels. To track the heat flux dynamics, the trajectories of massless probes inserted close to the origin are shown (black lines), and they propagate through the heat flux field until they leave the system (black dots). Away from resonance, the probes travel along a more direct path to the F or D channel exit (Figures 16D and 16E). At resonance, the probes cycle multiple times from F to D and from D to F before leaving the channel (Figure 16E). This dynamics describes the system's ability to reuse heat. The case of a slower resonant flow is shown in Figure 16G.

[0168] The basic modeling approach involves solving the Navier-Stokes equations for laminar flow in the channel region (when the device is operating in a low Reynolds number mode). The diffusion equation is solved in the membrane region, where the effects of both porosity and temperature are taken into account to describe the diffusion coefficient of water vapor within the membrane. The heat transfer equation is solved in all domains and includes convective heat transfer in the feed and distillate regions where fluids are present. Here, the differences between the exposed geometries and thermal properties in some embodiments can be magnified (primarily boundary conditions). In the following, unless otherwise specified, the inlet flow rate (Q) at ambient temperature is considered. F and Q D ).

[0169] The first model, Model 1, was used to replicate the indoor experimental conditions. The feed and distillate enter the device at a temperature of 25°C. An inflow boundary condition is used to account for the heat flow through the inlet boundary. The heat exchanger (orange area) is highly insulated and for simplicity, perfect insulation is assumed for this area. The experimental device is located on a cart made of steel, which can be considered as a heat sink whose temperature is fixed at room temperature, i.e. 20°C, due to its high thermal conductivity, which is used as a boundary condition. The bottom surface of the polycarbonate box is fixed to the membrane with screws that hold the device 5 mm from the top of the cart. The LED illuminates the device from a distance of 10 cm, but the glass of the LED lamp is located 5 cm from the top of the polycarbonate and it is heated by the LED dissipation to a measurement temperature of 40°C, which is used as a boundary condition. Additional convection losses and radiation losses from the top polycarbonate surface have been included. Because the LED is placed relatively close to the device, the convection contribution is expected to be reduced, and the convection coefficient h=0.1 (W / m 2 / K). An emissivity ∈ = 0.9 similar to that of a black body was chosen to evaluate the radiation losses. Convection losses and radiation losses were neglected in the bottom region, since the bottom surface of the polycarbonate layer reaches a temperature close to the 20 °C boundary condition fixed by the heat sink. All lateral boundaries were considered thermally insulating, since any losses could be neglected considering the finite thickness of the domain compared to the lateral extension of the device.

[0170] The second model, Model 2, was used to calculate the data for Figures 10A-10D. The idea behind Figures 10A-10D is to estimate the performance of the experimental setup outdoors and at different sizes. Therefore, the model is the same as in the previous section, except for the changed dimensions and boundary conditions. In particular, the LEDs are replaced by sunlight intensity, and the top polycarbonate surface now exchanges heat with the environment: a thick air layer is considered to terminate at an infinite element to simulate outdoor conditions. Convective and radiative losses refer to an outdoor temperature of 20°C, and h = 5 (W / m 2 / K) to simulate unforced natural convection.

[0171] The third model, Model 3, is used Figures 10E-10F to calculate the data. Figures 10E-10F The optimization model considered in is based on the same principles of Model 1 and Model 2, but with the following differences. The device is now considered to be placed on an aerogel substrate (which is more thermally insulating compared to polycarbonate: poly =0.19(W / m / K) Compared with aero = 0.017 (W / m / K)). In order to minimize radiation losses, it is assumed that an infrared reflector is placed above the polycarbonate top layer with an emissivity of ∈ = 0.01. Finally, in order to study the influence of possible losses in the heat exchanger area, a changed heat transfer coefficient h is chosen for the two HX surfaces. coeff=0.1-5 (W / m / K), now assuming that the surface dissipates heat through an environment of 20°C.

[0172] Steering Fig.21A and 21B , Fig.21A and 21B Examples of solar desalination using a resonant thermal oscillator with energy storage capability are shown after several hours of treatment for cloudy and sunny days, respectively. The examples shown are simulations based on solar data obtained in Alamogordo, NM.

[0173] Steering Fig. 22 , Fig. 22 The thermal conductivity K of HX material is shown HX =m COND ×400(W / (mK))reduction effect, where m COND is the multiplication factor comparing a given thermal conductivity to another. Considering the low velocities (<1 mm / s) of both the feed and distillate fluids relative to the length of the HX (40.6 cm), unless the thermal conductivity drops significantly (m COND <0.001), otherwise the thermal conductivity has little effect on heat recovery. The small flux reduction observed for high thermal conductivities may be due to the well-insulated HX region that is different from the membrane region exposed to the environment through the illumination window. Therefore, the larger thermal conductivity suggests that the heat is recycled closer to this membrane region, which may be more exposed to external losses.

[0174] Steering Figures 23A-23D , Fig.23A The fresh water flux rate and maximum temperature in the system are shown as the thickness (w) of the feed and distillate channels changes from 0.5 mm to 50 mm. This parameter also significantly affects the system performance, showing a peak at w ~ 1.6 mm. Figures 23B-23D middle, Figures 23B-23D The temperature and heat flux vector fields are shown for w ~ 0.5 mm, 1.6 mm and 50 mm, respectively. A higher maximum temperature does not necessarily correlate to better performance, since different losses may consume more input power as the temperature increases.

[0175] Steering Fig.24 , Fig.24 A flow chart 2400 is shown that describes a method for a resonant thermal oscillator in a thermal fluid system according to one or more embodiments. It should be understood that one or more of the steps in the flow chart may be omitted, repeated, and / or performed in a different order than shown. Therefore, the scope of the present invention should not be considered to be limited to the specific arrangement of steps shown in the flow chart.

[0176] In step 2402, the nanophotonics-driven solar membrane distillation system and the dynamic heat recovery system can be combined into a coupled system, wherein at least two countercurrent liquid streams separated by a membrane, including a feed stream and a distillate stream, are matched. In step 2404, heat energy can be recycled into the feed stream through the coupled system of the nanophotonics-driven solar membrane distillation system and the dynamic heat recovery system.

[0177] In step 2406, operation can be enabled by the coupled system of the nanophotonics driven solar membrane distillation system and the dynamic heat recovery system when no light is incident on the coupled system.

[0178] Thermofluid systems using the heat transfer mechanism disclosed herein can be used for different applications. For example, the system disclosed herein can be used for desalination applications, such as the NESMD and STREED systems described in the above discussion. In some embodiments, the system disclosed herein can use overall temperature control in a thermal oscillator to strengthen a process, such as a process with a chemical reaction. For example, a chemical reaction can be accelerated at an elevated temperature. The use of a thermal fluid system according to an embodiment of the present disclosure as a thermochemical reactor may include at least two countercurrent liquid streams, at least one of which contains a chemical precursor for a chemical reaction in a resonant thermal oscillator. By using a thermal oscillator in a system disclosed herein to accumulate thermal energy, the temperature in the system can be increased to accelerate the chemical reaction of one or more chemical precursors. In addition, if the light absorbing layer separating the fluid channels in the thermal fluid system disclosed herein is modified to include a material for a catalytic chemical reaction of interest, a low-cost power input (such as sunlight) can be used to increase the rate at which the reaction proceeds. In this way, any liquid phase thermal reaction can be enhanced by a thermal oscillator.

[0179] In some embodiments, the system disclosed herein can be used for thermal energy accumulation, wherein keeping the thermal oscillator resonant can keep the heat in the system captured. Therefore, the system takes longer to return to ambient temperature, even when the light source is turned off. Therefore, compared with conventional solar energy technologies whose functions suddenly decrease when the light is reduced (e.g., at night), the thermal oscillator used in the system of the present disclosure can store thermal energy for a longer time, and can at least partially operate even when the light is blocked (e.g., blocked by clouds) or stopped (e.g., at night). In this way, the system according to the embodiment of the present disclosure can use the thermal oscillator as a thermal battery. The thermal battery can be used to store heat, which can be used to drive the thermal process later. In addition, the system used as a thermal battery can be controlled to control charging (storing heat) and discharging (extracting heat) by controlling the operation of the thermal oscillator under resonance or non-resonance. Because resonance can be simply controlled by tuning the input flow rate, the use of the thermal oscillator in the system disclosed herein can provide a fluid-driven thermal battery. The system according to the embodiment of the present disclosure can be used as a thermal battery for various applications, such as cooling and heating in electric vehicles.

[0180] While the present disclosure has been described with reference to a limited number of embodiments, those skilled in the art having benefit of this disclosure will appreciate that other embodiments can be designed which do not depart from the scope of the present disclosure as disclosed herein. Accordingly, the scope of the present disclosure should be limited only by the appended claims.

Claims

1. A system, comprising: Thermal fluid systems; a thermal resonator coupled to the thermal fluid system; At least two fluid channels (314, 322; 334) separated by at least one thermally conductive layer (320), the thermally conductive layer (320) being configured to transfer heat in antiparallel directions through at least two fluids respectively flowing in countercurrent in the at least two fluid channels (314, 322; 334), thereby generating opposite temperature gradients across the at least two fluids in a cyclic, oscillating manner; and means (308) for adjusting the relative flow rates of the at least two fluids to control the oscillations and thereby the accumulation of thermal energy within the at least two fluids, Wherein the thermal fluid system and the thermal resonator are configured to confine and recirculate thermal energy multiple times through a combination of cyclic heat transfer mechanisms between the two fluids.

2. The system of claim 1, wherein the means for adjusting the relative flow rates of the at least two fluids is configured to set an equal heat content rate of the at least two fluids.

3. The system of claim 1 or claim 2, wherein the means for regulating the relative flow rates of the at least two fluids is an input power dependent flow controller (308).

4. The system of any one of claims 1-3, wherein the system further comprises an external heat source for heating the at least two fluids, the external heat source comprising a solar heat source and the at least one thermally conductive layer (320) comprising a solar absorbing thermally conductive layer.

5. The system of claim 1 or claim 2, wherein the system further comprises an internal heat source for heating the at least two fluids.

6. The system of any one of claims 1-5, wherein the oscillating thermal energy is configured to support a continuous thermal process.

7. The system of claim 6, wherein the thermal fluid system is selected from the group consisting of a distillation system, a water purification system, a fluid separation system, a thermochemical reactor, and a thermal fluid separation system based on a phase change separation method.

8. A method comprising: supply: a thermal resonator coupled to the thermal fluid system; At least two fluid channels (314, 322; 334) separated by at least one heat-conducting layer (320), the heat-conducting layer (320) being configured to transfer heat in anti-parallel directions through at least two fluids respectively flowing in countercurrent in the at least two fluid channels (314, 322; 334), Producing opposite temperature gradients across the at least two fluids in a cyclic, oscillating manner; adjusting the relative flow rates of the at least two fluids to control the oscillations and thereby the accumulation of thermal energy within the at least two fluids; as well as By means of the thermal fluid system and the thermal resonator, thermal energy is confined and recirculated multiple times through a combination of cyclic heat transfer mechanisms between the two fluids.

9. The method of claim 8, wherein adjusting the relative flow rates of the at least two fluids is performed to set an equal heat content rate of the at least two fluids.

10. The method of claim 8 or claim 9, wherein regulating the relative flow rates of the at least two fluids is performed by a flow controller (308) that is dependent on input power.

11. The method of any one of claims 8-10, wherein the method further comprises externally heating the at least two fluids by means of a solar heat source, the at least one thermally conductive layer (320) comprising a solar absorbing thermally conductive layer.

12. The method of claim 8 or claim 9, wherein the method further comprises internally heating the at least two fluids by means of an internal heat source.

13. The method of any one of claims 8-12, wherein the oscillating thermal energy is configured to support a continuous thermal process.

14. The system of claim 13, wherein the thermal fluid system is selected from the group consisting of a distillation system, a water purification system, a fluid separation system, a thermochemical reactor, and a thermal fluid separation system based on a phase change separation method.

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