A temperature control system of an ammonia water preparation device based on thermoacoustic effect

Abstract

The application discloses a temperature control system of an ammonia water preparation device based on a thermoacoustic effect. The temperature control method inputs electric power into an electrically-driven thermoacoustic conversion device arranged in an ammonia water circulation loop, establishes an oscillating heat flow in the loop, utilizes the thermoacoustic heat pump effect of the oscillating heat flow to regulate the temperature of the ammonia water, simultaneously utilizes the acoustic flow effect to drive directional circulation flow of the ammonia water, determines a target electric power value according to target temperature information and current temperature information, and adjusts the electric power to simultaneously regulate a temperature regulation rate and a circulation flow rate. The part of the ammonia water circulation loop in contact with the ammonia water is a static fluid passage without mechanical moving parts, which eliminates the failure mode of dynamic seal corrosion leakage from a physical mechanism, simplifies the system structure and improves operation reliability.

Description

Technical Field

[0001] This invention relates to the field of chemical process control technology, and in particular to a temperature control system for an ammonia preparation device based on the thermoacoustic effect. Background Technology

[0002] In the ammonia preparation process, temperature control during dissolution and homogenization of solution circulation are crucial for ensuring product concentration accuracy and production safety. With the chemical industry's increasing demands for production continuity and safety standards, the reliability and ease of maintenance of ammonia preparation temperature control systems have become a focus of industry attention.

[0003] Existing ammonia preparation temperature control systems treat temperature control and solution circulation as two independent engineering problems, using heat exchangers for temperature regulation and circulation pumps for solution driving. Temperature control is achieved by adjusting the flow rate of the hot and cold media in the heat exchanger or by electric heating power, while solution circulation is achieved by a motor-driven mechanical pump.

[0004] In relevant ammonia preparation temperature control technologies, traditional circulating pumps contain mechanical moving parts such as rotating shafts, impellers, and bearings, as well as dynamic sealing structures. The strong corrosiveness of ammonia causes long-term corrosion and aging of the mechanical seals and pump body materials, leading to seal failure and ultimately ammonia leakage, posing safety hazards and environmental pollution. Furthermore, the use of two independent systems for temperature control and circulation drive results in a complex system composition, numerous pipeline connection points, low overall reliability, and the inability to achieve coordinated control of temperature and circulation speed.

[0005] In summary, the aforementioned defects result in high maintenance costs, long downtime, and significant safety risks for ammonia preparation systems. In particular, the problem of corrosion and leakage of dynamic seals has not been fundamentally resolved for a long time, which seriously restricts the automation level and operational economy of the ammonia preparation process. Summary of the Invention

[0006] In view of the above problems, the present invention provides a temperature control system for an ammonia preparation device based on thermoacoustic effect, which can simultaneously realize the dual functions of temperature regulation and circulation drive without moving sealing components in the ammonia circulation loop.

[0007] In some embodiments, a temperature control method for an ammonia preparation apparatus based on thermoacoustic effect includes: inputting electrical power into an electrically driven thermoacoustic converter disposed in an ammonia circulation loop to establish an oscillating heat flow in the ammonia circulation loop; regulating the temperature of the ammonia using the thermoacoustic heat pump effect of the oscillating heat flow, and driving the ammonia to directional circulation using the acoustic flow effect of the oscillating heat flow; determining a target electrical power value based on the target temperature information and current temperature information of the ammonia, and adjusting the electrical power input to the thermoacoustic converter to the target electrical power value to simultaneously regulate the temperature regulation rate and the circulation flow rate. Here, temperature regulation and directional circulation are achieved simultaneously through the same oscillating heat flow, and the fluid passage portion in the ammonia circulation loop that comes into contact with the ammonia is a static fluid passage without mechanical moving parts or dynamic sealing structures.

[0008] In this embodiment, by introducing thermoacoustic technology into the temperature control scenario of ammonia preparation, the dual functions of temperature regulation and circulation drive are achieved in a single physical mechanism by utilizing the heat pump effect and acoustic flow effect of thermoacoustic oscillation. This fundamentally eliminates the mechanical moving parts and dynamic sealing structure of the ammonia contact surface, solves the core problem of sealing failure caused by ammonia corrosion, and greatly simplifies the system structure.

[0009] In some embodiments, the ammonia water circulation loop includes a thermoacoustic working chamber section, which encapsulates a compressible gaseous working fluid. An electrically driven thermoacoustic conversion device drives the gaseous working fluid to generate oscillations. Heat from the heat pump effect is transferred to the ammonia water or extracted from the ammonia water through the static heat exchange walls at both ends of the thermoacoustic working chamber section. The driving force of the acoustic flow effect is transferred to the ammonia water through a flexible coupling element to achieve circulation drive.

[0010] In this embodiment, by setting a thermoacoustic working cavity section encapsulating a compressible gaseous working fluid in the circulation loop, the thermoacoustic heat pump circulation is completed in a highly compressible gas to ensure the high efficiency of the thermoacoustic effect. At the same time, the temperature regulation and circulation drive functions are transferred to the ammonia water side through the static heat exchange wall and flexible coupling element. There is no dynamic seal contact between the gas and the ammonia water, which structurally ensures the fully static characteristics of the ammonia water passage.

[0011] In some embodiments, a weighted optimization strategy is used to determine the target electrical power value based on temperature deviation and flow rate deviation. When there is a conflict between the electrical power demand corresponding to the temperature deviation and the electrical power demand corresponding to the flow rate deviation, the primary process objective is prioritized based on a preset process priority weighting factor.

[0012] In this embodiment, a weighted optimization strategy is used to resolve the potential conflict between temperature and flow rate targets in a single-input dual-output control architecture, enabling the system to allocate control resources reasonably under various operating conditions.

[0013] In some embodiments, the acoustic resonant frequency of the thermoacoustic working cavity section in the ammonia water circulation loop is used as the driving frequency of the electric power, and adaptive adjustment is made when the resonant frequency drifts due to changes in operating conditions.

[0014] In this embodiment, the system is kept operating at its most efficient point by resonant frequency tracking, thus avoiding performance degradation caused by deviation from resonance.

[0015] In some embodiments, the ammonia circulation loop is provided with an asymmetric acoustic coupling structure, which enables the oscillating heat flow to generate a time-averaged net driving force on the ammonia in a single direction through a flexible coupling element.

[0016] In this embodiment, the asymmetric acoustic coupling structure ensures that the acoustic flow effect generates a directional circulating flow, thereby realizing directional liquid delivery without a mechanical pump.

[0017] In some embodiments, the thermoacoustic working cavity section includes a regenerator section and a heat exchanger section. When the oscillating heat flow passes through the regenerator section, net heat transport is generated through the periodic compression and expansion of the gaseous working fluid micro-particles and the reciprocating heat exchange with the solid matrix.

[0018] In this embodiment, the high compressibility of the gaseous working fluid ensures that the gas microparticles generate significant temperature oscillations within each oscillation cycle, and efficient directional heat transport is achieved through the functional zoning of the regenerator section and the heat exchanger section.

[0019] According to a second aspect of the present invention, a temperature control system for an ammonia preparation apparatus is provided, comprising an ammonia circulation loop, an electrically driven thermoacoustic conversion device, and an electric power regulation unit.

[0020] According to a third aspect of the present invention, an electronic device is provided, including a memory and a processor coupled to the memory, the processor being configured to perform the temperature control method described above.

[0021] According to a fourth aspect of the present invention, an ammonia preparation apparatus is provided, comprising a dissolution and mixing unit and the temperature control system described above.

[0022] According to a fifth aspect of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the above-described temperature control method.

[0023] In summary, the temperature control system for an ammonia preparation device based on the thermoacoustic effect of the present invention has the following beneficial effects:

[0024] 1. Dual-Function Unified Elimination of Dynamic Seal Requirements: By placing an electrically driven thermoacoustic conversion device in the ammonia water circulation loop, the dual functions of temperature regulation and circulation drive are achieved by utilizing the simultaneous heat pump effect and acoustic flow effect of thermoacoustic oscillation. This makes the part of the entire ammonia water circulation loop in contact with ammonia water a static fluid passage without mechanical moving parts, thus physically eliminating the dynamic seal structure. Compared with the safety hazard of ammonia leakage caused by the sealing failure of the circulation pump in the prior art, this invention eliminates the failure mode of seal corrosion leakage. The inventive point of this invention lies in transferring thermoacoustic technology from its fields of cryogenic cooling in space and natural gas liquefaction to ammonia water preparation chemical equipment, and solving the contradiction between the physical requirement of thermoacoustic effect on the compressibility of the working fluid and the liquid characteristics of ammonia water through the indirect coupling architecture of gaseous working fluid thermoacoustic circulation and liquid ammonia water loop.

[0025] 2. Simplified single-input dual-output control architecture: By adjusting a single electrical power input to control the intensity of thermoacoustic oscillations, the heat transfer rate and circulation velocity are simultaneously regulated. This achieves a control architecture where one control input simultaneously affects two process variables. Compared to the complex multi-loop coordination strategies in existing technologies where the heat exchanger and circulation pump are controlled independently, this invention reduces the control dimension from two to one, decreasing the complexity of the control system and the number of actuators. The coupling relationship between temperature and flow rate is determined by thermoacoustic physics itself, causing the circulation to automatically strengthen as the heating intensity increases, which is beneficial for temperature homogenization.

[0026] 3. Simplified system structure and improved reliability: By replacing the heat exchanger and circulating pump with a single thermoacoustic conversion device, the number of pipeline connection points and equipment is reduced. Compared with the potential leakage risks and system complexity caused by the large number of equipment and connection points in the prior art, the number of equipment and pipeline connection points of the present invention is significantly reduced, the long-term trouble-free operation time of the system is increased, and maintenance costs and downtime are reduced.

[0027] 4. Resonance Adaptation and Coupling Conflict Optimization: By using an acoustic resonant frequency adaptive tracking mechanism to maintain the system at its highest efficiency point, and by using a weighted optimization strategy to coordinate the conflict between temperature and flow rate targets, this invention can adapt to changes in operating conditions and maintain control accuracy and energy utilization efficiency across the entire operating range, compared to traditional fixed parameter control strategies. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of the temperature control system of the ammonia preparation device provided in an embodiment of the present invention.

[0029] Figure 2 This is a schematic diagram of the main process of the temperature control method provided in an embodiment of the present invention.

[0030] Figure 3This is a schematic diagram of the sub-process for determining and weighting the power according to an embodiment of the present invention.

[0031] Figure 4 This is a schematic diagram of a sub-process for adaptive resonant frequency tracking provided in an embodiment of the present invention.

[0032] Figure 5 A schematic diagram of the coupling relationship between electrical power, temperature regulation rate, and circulation flow rate provided for embodiments of the present invention.

[0033] Figure 6 This is a schematic diagram of the functional modules of the temperature control device provided in an embodiment of the present invention.

[0034] Figure 7 This is a schematic diagram of the hardware architecture of an electronic device provided in an embodiment of the present invention.

[0035] Figure 8 This is a schematic diagram illustrating an application scenario of the ammonia preparation device provided in an embodiment of the present invention. Detailed Implementation

[0036] The technical solution of the present invention will now be clearly and completely described in conjunction with the accompanying drawings and embodiments.

[0037] Terminology Explanation

[0038] In the description of this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or an implicit order of arrangement. And / or describing the relationship between related objects, indicating that three relationships may exist, for example, A and / or B, which can represent three situations: A existing alone, A and B existing simultaneously, and B existing alone.

[0039] In this invention, connection can refer to physical connection, fluid connection or signal connection; oscillating heat flow refers to the heat transport flow accompanied by the periodic pressure wave and displacement wave oscillation generated by the thermoacoustic effect; acoustic flow refers to the time-averaged directional net flow generated by nonlinear effects when sound waves propagate in a fluid; thermoacoustic working cavity section refers to a sealed cavity section encapsulating a compressible gas working medium for realizing thermoacoustic circulation; flexible coupling element refers to a static sealing element that connects the gas working medium side and the ammonia water side, can be elastically deformed but has no sliding friction surface, such as a metal bellows or a flexible diaphragm.

[0040] Background Information

[0041] Thermoacoustic effect is a coupling phenomenon between sound waves and thermodynamic processes. When sound waves (periodic pressure oscillations) propagate in a pipe containing a solid porous medium (regenerator), fluid particles undergo periodic compression and expansion processes. For compressible gaseous working fluids, pressure oscillations cause significant temperature oscillations, i.e., heating during compression and cooling during expansion. The irreversible reciprocating heat exchange between the gas particles and the solid matrix leads to net heat transport along the direction of sound wave propagation, i.e., the thermoacoustic heat pump effect. Simultaneously, the nonlinear effects in sound wave propagation produce time-averaged directional net flow, i.e., the acoustic flow effect.

[0042] The effectiveness of thermoacoustic effects depends on the compressibility of the working fluid. Gaseous working fluids (such as helium and nitrogen) can produce significant adiabatic temperature changes under acoustic pressure oscillations, making them ideal working fluids for thermoacoustic devices. Liquids, due to their extremely high volumetric compressibility modulus (approximately 10^4 to 10^5 times that of gases), exhibit extremely weak temperature oscillations under the same acoustic pressure, making them unsuitable as direct working fluids for thermoacoustic cycles. Therefore, this invention employs a technical architecture that indirectly couples a gaseous thermoacoustic cycle with a liquid ammonia circuit, enabling the thermoacoustic effect to be completed in a highly efficient gaseous environment. Temperature regulation and cycle drive functions are then transferred to the ammonia side via a static heat exchange surface and flexible coupling elements.

[0043] like Figure 2 As shown, this embodiment of the invention provides a temperature control method for an ammonia preparation device based on the thermoacoustic effect, including the following steps.

[0044] Step S101: Input electrical power into the electrically driven thermoacoustic converter device installed in the ammonia water circulation loop to establish an oscillating heat flow in the ammonia water circulation loop.

[0045] like Figure 1 As shown, the ammonia circulation loop includes a thermoacoustic working chamber section, which encapsulates a high-pressure compressible gaseous working fluid (such as helium or nitrogen). An electrically driven thermoacoustic conversion device is located within the thermoacoustic working chamber section, which, driven by electrical power, causes the gaseous working fluid to generate acoustic wave oscillations, establishing an oscillating heat flow.

[0046] The oscillating heat flow is thermodynamically and mechanically coupled with the ammonia water side through the heat exchange walls and flexible coupling elements at both ends of the thermoacoustic working cavity section, thereby realizing the temperature regulation and circulation drive functions of the oscillating heat flow in the ammonia water circulation loop at the system level.

[0047] In some embodiments, the thermoacoustic conversion device is a linear motor-driven transducer. The piston of the linear motor reciprocates linearly under the drive of alternating current, directly generating sound waves in the gaseous working medium. A static seal is achieved between the piston and the gas chamber through a flexible seal using a metal bellows or leaf springs, ensuring that the piston movement does not contact the ammonia solution. For example, inputting 500W of electrical power to the linear motor establishes an oscillation with a sound pressure amplitude of approximately 300kPa within the thermoacoustic working chamber filled with 3MPa helium gas, resulting in a sound pressure ratio of approximately 10%.

[0048] In some embodiments, the thermoacoustic conversion device is a piezoelectric ceramic driven transducer, suitable for higher frequency and miniaturized applications.

[0049] In some embodiments, the thermoacoustic conversion device is an electrically driven loudspeaker transducer, including a voice coil, a magnet, and a diaphragm. The diaphragm is in direct contact with the gaseous working fluid and forms a statically sealed boundary without a sliding friction sealing surface. The electrically driven loudspeaker transducer has limited diaphragm pressure resistance and stroke, making it suitable for small to medium-sized ammonia preparation devices with low average gas pressure (e.g., 0.1 MPa to 0.5 MPa, corresponding to the embodiments described later that reduce the average gas pressure to be close to the operating pressure of the liquid circuit) and low required electrical power (e.g., below 200 W).

[0050] In such low average pressure embodiments, the sound pressure ratio or the cross-sectional area of ​​the thermoacoustic working cavity needs to be increased accordingly to maintain the required heat transport power and cyclic driving capability; a sealed back cavity is provided on the back side of the speaker diaphragm and filled with gas at the same average pressure as the working cavity, so that the static pressure on both sides of the diaphragm is balanced and only bears the alternating sound pressure load.

[0051] In some embodiments, the driving frequency is selected as the acoustic resonant frequency of the thermoacoustic working cavity. For a helium-filled working cavity, the resonant frequency is calculated as follows:

[0052] f res =c He / (2×L TA )

[0053] Among them, f res Where c is the resonant frequency. He L is the speed of sound in helium (approximately 1000 m / s at 300 K and 3 MPa). TA This is the acoustically effective length of the thermoacoustic working cavity section.

[0054] For example, let the effective length L of the thermoacoustic working cavity be... TA =0.5m, filled with 3MPa helium gas, the speed of sound is about 1000m / s, then the resonant frequency f res =1000 / (2×0.5)=1000Hz. Operating at the resonant frequency maximizes the conversion efficiency of electrical energy to sound energy.

[0055] In some embodiments, to accommodate lower frequency requirements (50 to 200 Hz), this can be achieved by increasing the cavity length or extending the acoustic path using an acoustic inertial tube.

[0056] In the ammonia water circulation loop, except for the thermoacoustic working chamber section, the part is a pure liquid ammonia water passage. All the parts that come into direct contact with the ammonia water are static structures without mechanical moving parts and are made of ammonia water corrosion resistant materials.

[0057] In this embodiment, a thermoacoustic working chamber containing a high-pressure compressible gaseous working fluid is integrated into the ammonia circulation loop, enabling efficient establishment of thermoacoustic oscillations in a gaseous environment. The high compressibility of the gaseous working fluid ensures significant temperature oscillations in the sound waves (helium gas exhibits an adiabatic temperature change of over ten degrees Celsius at a 10% sound pressure ratio), providing a foundation for the effective operation of the thermoacoustic heat pump effect. The linear motor piston is isolated from the gas chamber by a flexible seal, preventing contact with the ammonia and fundamentally eliminating the need for dynamic sealing on the ammonia side.

[0058] Step S102: The temperature of ammonia in the ammonia circulation loop is regulated by the thermoacoustic heat pump effect of oscillating heat flow, and the ammonia is driven to circulate in a directional manner in the ammonia circulation loop by the acoustic flow effect of oscillating heat flow.

[0059] After the oscillating heat flow is established in the thermoacoustic working cavity, two physical effects are generated and transferred to the ammonia water side: the thermoacoustic heat pump effect transfers heat to the ammonia water through the heat exchange wall or extracts heat from the ammonia water to regulate the temperature, and the acoustic flow effect transfers the driving force to the ammonia water through the flexible coupling element to achieve circulation.

[0060] In some embodiments, the thermoacoustic working chamber section includes a regenerator section and heat exchanger sections at both ends. The regenerator section is filled with a porous solid matrix with a high specific surface area, such as a stack of stainless steel wire mesh (80 to 200 mesh) or a parallel plate structure. As the oscillating heat flow passes through the regenerator section, the gaseous working fluid particles undergo the following process in each oscillation cycle: compression and heating – heat release to the solid matrix – displacement to the high-temperature side – expansion and cooling – heat absorption from the solid matrix – displacement to the low-temperature side. Due to the asymmetry of heat exchange at different locations of the gaseous particles, a net heat transport along the oscillation direction is generated.

[0061] The amplitude of the adiabatic temperature oscillation of the gaseous working medium in the sound wave is:

[0062] ΔT adiabatic =T mean ×(γ-1) / γ×(p1 / p mean );

[0063] Where, ΔT adiabatic T represents the amplitude of the adiabatic temperature oscillation. mean The average temperature (K), γ is the specific heat ratio of the gas (γ=5 / 3 for helium), p1 is the sound pressure amplitude, and p mean This represents the average pressure.

[0064] For example, in T mean =300K, helium γ=5 / 3, p mean Under the conditions of 3MPa and p1=300kPa (sound pressure ratio 10%):

[0065] ΔT adiabatic=300×(5 / 3-1) / (5 / 3)×(300000 / 3000000)=300×0.4×0.1=12℃

[0066] The temperature of the gas microparticles changes by 12°C in each oscillation cycle. The temperature oscillation ensures effective reciprocating heat exchange between the gas and the solid matrix in the regenerator, thereby achieving efficient net heat transport.

[0067] The heat exchanger sections are located at both ends of the regenerator section, namely the first heat exchanger section and the second heat exchanger section. The thermoacoustic heat pump effect establishes a temperature difference between the two ends of the regenerator, making one end the high-temperature side and the other the low-temperature side. In cooling mode (used to remove the heat released from ammonia dissolution to maintain the target temperature), the outer surface of the low-temperature side heat exchanger section is in thermal contact with the ammonia water in the ammonia water circulation loop, absorbing heat Q from the ammonia water side through the metal wall. c The high-temperature heat exchanger section is in thermal contact with the external heat dissipation circuit, transferring heat Q. h =Q c +W input It is discharged to an external heat dissipation medium (such as circulating cooling water or a finned air radiator). In heating mode, the high-temperature side heat exchanger section comes into thermal contact with the ammonia water and releases heat Q to it. h The low-temperature heat exchanger section absorbs heat Q from an external heat source (such as ambient air or low-temperature waste heat). c .

[0068] In some embodiments, the system operates in a fixed cooling mode to continuously remove the heat released from ammonia dissolution. In this mode, only the low-temperature heat exchanger section is in thermal contact with the ammonia-water circuit, while the high-temperature side is connected to the plant's circulating cooling water system. (Thermoacoustic heat pump cooling performance coefficient COP) c =Q c / W input Under typical operating conditions, the value is approximately 0.8 to 1.5, which corresponds to an electrical power of 500W, from which 400W to 750W of heat can be extracted from ammonia water.

[0069] In embodiments requiring switching between hot and cold modes, a first electrically driven thermoacoustic conversion device and a second electrically driven thermoacoustic conversion device are respectively provided at both ends of the thermoacoustic working cavity section, with the regenerator section located between the two.

[0070] The power regulation unit controls the amplitude and relative phase of the two alternating currents respectively. When the first device operates in active sound generation mode and the second device operates in controlled acoustic load mode (i.e., controlling its piston speed phase to absorb acoustic power), the acoustic power flows from the first end through the regenerator to the second end, and the thermoacoustic heat pump pumps heat in this direction. By reversing the master-slave roles of the two devices, i.e., reversing the direction of acoustic power flow, the high-temperature end and the low-temperature end are interchanged, and the system switches from cooling mode to heating mode, and vice versa. The above switching is achieved only by adjusting the amplitude and relative phase of the two driving currents, without changing the mechanical structure, and the ammonia-water side passage always remains completely static. The embodiment using a single thermoacoustic conversion device is suitable for occasions where it is fixed to operate in cooling mode (or heating mode).

[0071] The coefficient of performance (COP) of a thermoacoustic heat pump is:

[0072] COP h =Q h / W input ;

[0073] Among them, COP h Q is the coefficient of performance for heating. h W is the heat released into the ammonia solution. input This refers to the input electrical power.

[0074] For example, when the electrical power input is 500W, the COP of the thermoacoustic heat pump is... h Approximately 1.5 to 2.0, corresponding to the heat Q released into the ammonia solution. h =750W to 1000W, a temperature difference of about 15 to 25°C can be established at both ends of the regenerator.

[0075] In some embodiments, the ammonia circulation loop is mechanically coupled to the acoustic flow effect in the thermoacoustic working cavity through a flexible coupling element to achieve circulation drive. The flexible coupling element can be a metal bellows or an elastic diaphragm, located at the interface between the thermoacoustic working cavity and the ammonia passage.

[0076] It should be noted that the physical mechanism of acoustic flow-driven liquid circulation in this invention is not to allow the direct current mass flow of gas to penetrate the flexible coupling element, but rather to utilize the rectification effect generated by the asymmetric acoustic structure to achieve the following working process: On the gas side, the working gas in the thermoacoustic working cavity oscillates reciprocally under electrical drive. Due to the asymmetric acoustic coupling structure (e.g., a tapered tapered-expanding cross-section section, an asymmetric bend section, or a unidirectional resistance differential structure) set in the gas cavity, the gas experiences different flow resistances in the forward and reverse half-cycles (similar to the valveless rectification principle in the field of microfluidics). The flow rates in the forward and reverse directions are unequal in each oscillation cycle, and after time averaging, a directional net mass flow rate, i.e., DC acoustic flow, is generated on the gas side, and a time-averaged net pressure difference is established at both ends of the asymmetric section.

[0077] It should be noted that the manifestation of the gas-side DC acoustic flow depends on the acoustic topology of the thermoacoustic working cavity. When the thermoacoustic working cavity adopts a loop-type (traveling wave-type) acoustic path, the directional net mass flow can actually circulate along the gas loop, v gas_DC This refers to the time-averaged net mass flow velocity across the loop cross-section. When the thermoacoustic working cavity section uses a linear, sealed cavity, according to the law of mass conservation, the time-averaged net mass flow at any cross-section is zero under steady state. The rectifying tendency generated by the asymmetric structure is blocked by the cavity's sealing property, transforming into the time-averaged net pressure difference Δp between the two ends of the asymmetric section. DC Its value can be estimated as Δp based on the equivalent acoustic impedance voltage drop of the blocked acoustic flow. DC ≈ρ gas ×c gas ×v gas_DC (Based on the parameter values ​​in the flow rate estimation example below, it is approximately on the order of 1.3 kPa). This net pressure difference acts on the two flexible coupling elements, causing a definite offset in their average operating point.

[0078] Regardless of the topology used, the directional net circulation on the liquid side is achieved through a valveless rectification mechanism consisting of oscillating volume displacement with a defined amplitude and phase difference between two flexible coupling elements, combined with asymmetric flow resistance elements on the liquid side. The DC acoustic flow or net pressure difference on the gas side only serves to enhance the determinism of the rectification direction. Therefore, the velocity estimation formula chain presented below can be used as a preliminary engineering estimate under both topologies, with the final correction η determined by experimental calibration. coupling Then determine the actual circulation flow rate.

[0079] In some embodiments, a first flexible coupling element and a second flexible coupling element are provided between the ammonia water circulation loop and the thermoacoustic working cavity section. The two elements are located at the upstream and downstream ends of the asymmetric acoustic structure, respectively, and their liquid sides are connected to the first position point and the second position point on the ammonia water circulation loop, respectively.

[0080] Since the sealed flexible coupling element does not transmit net volumetric flow, the directional net circulation on the liquid side is not directly maintained by the time-averaged static pressure difference, but is achieved through an oscillating rectification mechanism. That is, under the action of acoustic oscillation, the two flexible coupling elements undergo reciprocating elastic deformation at the operating frequency (oscillation amplitude is on the order of micrometers to millimeters). Due to the asymmetric acoustic structure, the sound pressure amplitude and phase at both ends are different, and there is a definite amplitude difference and phase difference between the oscillating volume displacement of the two flexible coupling elements. At the same time, an asymmetric liquid-side flow resistance element, such as a converging-expanding nozzle / diffuser structure, is set in the liquid pipe section between the first and second position points in the ammonia loop, so that the flow resistance of the liquid is not equal in the two flow directions.

[0081] Two oscillating volume displacement sources with a phase difference, in conjunction with the liquid-side flow resistance asymmetric element, constitute a dual-chamber valveless pump structure: in each oscillation cycle, the volume of liquid discharged in the low-resistance direction is greater than the volume of liquid drawn back in the high-resistance direction, and the net difference in cycles, after time averaging, forms a continuous net circulating flow in a single direction along the loop. The time-averaged net pressure difference established by the gas-side asymmetric acoustic structure causes a definite bias in the average operating point of the two flexible coupling elements, further enhancing the directional certainty of the rectification. In an alternative embodiment, only one flexible coupling element can be used, with a rigid wall at the other end. The reciprocating volume displacement of a single flexible coupling element, combined with the liquid-side flow resistance asymmetric pipe section, constitutes a single-chamber valveless diaphragm pump, also achieving directional net flow, with a net flow rate approximately half that of the dual-chamber configuration.

[0082] It should be further noted that the average pressure of the gaseous working medium in the thermoacoustic working chamber is usually higher than the liquid operating pressure of the ammonia water circulation loop, and there is a static pressure difference on both sides of the flexible coupling element.

[0083] To ensure that the flexible coupling element maintains its oscillation transmission capability while withstanding static pressure difference, any of the following methods can be used:

[0084] Method 1: The flexible coupling element adopts a multi-layer metal diaphragm structure supported by a perforated rigid backplate. The static pressure difference is borne by the perforated backplate. The diaphragm undergoes only minor amplitude elastic deformation in the local area corresponding to the perforations in the backplate to transmit the oscillating volume displacement. The perforation ratio and aperture of the backplate are determined according to the required transmission efficiency η. coupling Design finalized;

[0085] Method 2: The ammonia water circulation loop is designed as a pressurized closed loop. The liquid static pressure is maintained at a level close to the average gas pressure through a diaphragm accumulator, and the dissolution and mixing unit is designed accordingly as a pressure vessel.

[0086] Method 3: In small-scale applications where power density requirements are not high, the average gas pressure is reduced to a level close to the operating pressure of the liquid circuit (e.g., 0.3 to 0.5 MPa), and the sound pressure ratio or the cross-sectional area of ​​the thermoacoustic working chamber is increased accordingly to maintain the required heat transport power and circulation drive capability. None of the above methods introduce any mechanical moving parts or dynamic sealing structures on the ammonia water side.

[0087] The average circulating velocity of ammonia water generated by acoustic flow is estimated in the following two steps.

[0088] First, determine the time-averaged acoustic velocity on the gas side: v gas_DC =K DC ×u1 2 / c gas ,

[0089] Where K DCK is the rectification coefficient of the asymmetric acoustic coupling structure, dimensionless, and depends on the geometric parameters of the asymmetric structure: for helium working fluid, 1000Hz oscillation frequency, and a sound pressure ratio of 10%, when the half-angle of the tapered variable cross-section is between 5° and 12°. DC Typical values ​​range from 0.03 to 0.10. Those skilled in the art can determine the specific structural parameters and K through acoustic impedance network simulation or experimental calibration. DC The correspondence; u1=p1 / (ρ gas ×c gas The amplitude of the gas acoustic velocity is denoted as v. The liquid-side flow velocity is determined as v. liquid =η coupling ×v gas_DC ×(A gas / A liquid ), where η coupling The product of the deformation transfer efficiency and the liquid-side valveless rectification efficiency of the flexible coupling element is characterized by a typical value of 0.5 to 0.7 for metal bellows, and the value is corrected by experimental calibration.

[0090] For example, let K DC =0.072 (half-angle of cone 8°), η coupling =0.6, p1=300kPa, ρ gas =4.8kg / m 3 (3MPa helium), c gas =1000m / s, A gas / A liquid =0.5. Therefore, u1 = 300000 / (4.8 × 1000) = 62.5 m / s; v gas_DC =0.072×62.5 2 / 1000≈0.281m / s; v liquid =0.6×0.281×0.5≈0.084m / s. For an ammonia water circulation pipeline with an inner diameter of 40mm, the corresponding volumetric flow rate is approximately 0.084×π×0.02 2 ×60000≈6.3L / min, which can meet the circulation requirements of a medium-sized ammonia water preparation plant; in situations requiring a lower circulation flow rate, the flow rate can be reduced by decreasing A. gas / A liquid The ratio or a lower K value should be selected. DC The mild asymmetric structure of the value reduces the circulation rate.

[0091] In this embodiment, the physical effectiveness and energy conversion efficiency of the heat pump cycle are ensured by completing the thermoacoustic heat pump effect in a highly compressible gas and transferring it to the ammonia water through a static heat exchange wall. The acoustic flow driving force is transferred to the ammonia water side via a flexible coupling element, achieving a liquid circulation drive without dynamic seals. Both functions are generated by the same oscillating heat flow; the automatic strengthening of the circulation as the heating intensity increases is beneficial for temperature uniformity, demonstrating the technical advantage of unifying dual functions.

[0092] Step S103: Determine the target electrical power value based on the target temperature information and the current temperature information of the ammonia water.

[0093] like Figure 3 As shown, the target temperature T of the ammonia solution is obtained. target and the current temperature T current Calculate the temperature deviation:

[0094] ΔT=T target -T current

[0095] Where ΔT is the temperature deviation, T target For the target temperature, T current This is the current temperature.

[0096] The target electrical power value is determined using electrical power-thermoacoustic effect mapping information. This mapping information includes the correspondence between the electrical power input value and the thermoacoustic oscillation intensity (determined by the electroacoustic transduction efficiency), as well as the mapping relationship between the thermoacoustic oscillation intensity and the temperature regulation capability and cycle drive capability (determined by thermoacoustic physics and coupling structure).

[0097] In some embodiments, the target power value is determined using a PID control strategy:

[0098] P target =K p ×ΔT+K i ×∫ΔTdt+K d ×dΔT / dt

[0099] Among them, P target K is the target electrical power value. p For proportional gain, K i For integral gain, K d This is the differential gain.

[0100] For example, let the target temperature T target =35℃, current temperature T current =28℃, temperature deviation ΔT=7℃. Let K p =70W / ℃, then the proportional term contribution is 490W. After integrating the integral and differential corrections, the target power value P is determined. target =520W.

[0101] In some embodiments, the current circulation flow rate information v of the ammonia water is also obtained. current and target circulation velocity information v target The target electrical power value is determined using a weighted optimization strategy based on temperature and flow rate deviations. The objective function for the weighted optimization is:

[0102] J(P)=w T ×(T(P)-T target ) 2 +w v ×(v(P)-v target ) 2

[0103] Where J(P) is the optimization objective function, w T w is the temperature deviation weighting coefficient. v is the flow velocity deviation weighting coefficient, T(P) is the steady-state temperature response corresponding to the electric power P, and v(P) is the steady-state circulating flow velocity corresponding to the electric power P.

[0104] The mapping relationship between T(P) and v(P) is established as follows.

[0105] Circulating velocity mapping v(P): due to v gas_DC With u1 2 Proportional, u1 is proportional to p1, while under acoustic resonance conditions p1 2 It is approximately proportional to the input electrical power P, therefore v(P) = K v The relationship between ×P and the proportionality coefficient K is approximately linear. v It is obtained through system calibration or by calculation according to the aforementioned formula chain.

[0106] The steady-state temperature mapping T(P) is determined by the heat balance equation of the ammonia water loop:

[0107] COP h ×P+Q dissolution =UA loss ×(T steady -T ambient )+Q process .

[0108] Q dissolution UA is the exothermic rate of ammonia dissolution. loss Q is the overall heat dissipation coefficient of the system. process Given the heat load of other processes, we can solve for T(P) = T ambient +(COP h ×P+Q dissolution -Q process ) / UA loss .

[0109] COP h An approximate constant can be taken near the current operating point; UA loss With Q dissolution It can be identified and calibrated through the system.

[0110] When the system is running in cooling mode, the COP in the equation h The inversion of term ×P is −COP. c ×P. In some embodiments, instead of using an analytical model, small power steps (e.g., ±5% of the current power) can be applied periodically during operation, and the steady-state changes in temperature and flow rate can be recorded. The linear approximate slope of the mapping relationship can be updated online to adapt to slow changes in operating conditions.

[0111] The target electrical power value is determined by minimizing J(P). When there is a conflict between the electrical power demand corresponding to temperature deviation and the electrical power demand corresponding to flow rate deviation, the primary process objective is prioritized based on a preset process priority weighting factor. For example, when temperature control is more important in the initial stage of ammonia dissolution, w is set... T / w v =5:1, adjusted to w when the cycle is more important in the homogenization stage. T / w v =1:3.

[0112] In this embodiment, the target power value is determined by a weighted optimization strategy, which solves the problem of potential conflict between the two targets in the single-input dual-output control architecture. This enables the system to flexibly allocate control resources according to the priority of different stages of the process, and achieve the optimal control effect under all operating conditions.

[0113] Step S104: Adjust the electrical power of the input thermoacoustic conversion device to the target electrical power value, so as to simultaneously regulate the temperature regulation rate and circulation flow rate by controlling the intensity of thermoacoustic oscillation.

[0114] The output of the power adjustment unit is adjusted to the target power value determined in step S103. When the power increases, the acoustic pressure amplitude generated by the thermoacoustic conversion device increases, the intensity of the oscillating heat flow increases, the heat transport rate of the heat pump effect accelerates, and the circulating driving force generated by the acoustic flow effect increases.

[0115] like Figure 5 As shown, the relationship between electrical power P and the temperature regulation rate dT / dt and the circulation velocity v is: the temperature regulation capability (heat transport power) is approximately proportional to the electrical power Q. h =COP h ×P; The circulating flow velocity is proportional to the square of the sound pressure amplitude, and the sound pressure amplitude is proportional to the square root of the electrical power. Therefore, the circulating flow velocity v and the electrical power P are approximately linearly related.

[0116] In some embodiments, when the target electrical power value is below the minimum power threshold P required to maintain effective thermoacoustic oscillations... min In this case, maintain the electrical power at P min For example, P min =30W. When the target power is calculated to be 15W, the actual output is maintained at 30W to maintain oscillation stability and cycle continuity.

[0117] In some embodiments, when the target power value exceeds the system rated power P max In this case, limit the power to P max It also issues a warning signal indicating insufficient system capacity. For example, P max =800W. When the target power is calculated to be 950W, the actual output is limited to 800W and an auxiliary means are required.

[0118] In this embodiment, the temperature regulation rate and circulation flow rate are synchronously controlled by adjusting the electrical power, and the minimum power constraint and maximum power constraint ensure the system stability and safety, respectively.

[0119] Optional step S105: resonant frequency adaptive tracking.

[0120] like Figure 4 As shown, when changes in operating conditions cause the acoustic resonant frequency of the thermoacoustic working cavity to drift, the driving frequency is adaptively adjusted.

[0121] Factors affecting the resonant frequency include: changes in the gas temperature distribution within the thermoacoustic working cavity (affecting local sound velocity), and the influence of changes in the heat exchanger section wall temperature on the gas-side temperature boundary conditions.

[0122] For example, when the average temperature of helium gas in the thermoacoustic working chamber increases from 300K to 320K, the sound velocity changes from approximately 1000m / s to approximately 1033m / s, corresponding to a resonant frequency drift of about 3.3%. When the concentration and / or temperature of ammonia changes, on the one hand, the exothermic intensity of ammonia dissolution varies with concentration and dissolution rate; on the other hand, the heat exchange temperature difference between ammonia and the heat exchanger wall changes with ammonia temperature. Both of these factors lead to changes in the heat exchanger wall temperature, which in turn alters the temperature and sound velocity distribution of the gaseous working fluid within the thermoacoustic working chamber, ultimately manifesting as a drift in the acoustic resonant frequency. Therefore, adaptive adjustment of the driving frequency can track the resonant frequency drift caused by changes in ammonia concentration and / or temperature, maintaining the resonant operating state.

[0123] The adaptive adjustment process includes: by monitoring the impedance change of the thermoacoustic conversion device or the sound pressure amplitude response detected by the sound pressure sensor, performing a small-range frequency sweep around the current driving frequency, and determining the frequency corresponding to the maximum sound pressure amplitude (or minimum impedance) as the updated resonant frequency.

[0124] In some embodiments, the frequency sweep range is set to ±3% of the current resonant frequency, the sweep step size is 1Hz, and a frequency check is performed every 120 seconds. For example, if the current resonant frequency is 1000Hz and the sweep range is 970Hz to 1030Hz, if the maximum sound pressure amplitude is detected at 1015Hz, the driving frequency is updated to 1015Hz.

[0125] In this embodiment, the resonant frequency adaptive tracking mechanism ensures that the system always maintains the highest efficiency operating point as operating conditions change, thus avoiding a decrease in energy conversion efficiency caused by deviation from resonance.

[0126] like Figure 6 As shown in the figure, an embodiment of the present invention provides a temperature control device for an ammonia preparation apparatus, which includes the following functional modules.

[0127] The oscillation establishment module is used to control the electrical power input to the thermoacoustic conversion device to establish an oscillating heat flow in the gaseous working medium of the thermoacoustic working cavity. This module corresponds to the function of step S101 in the method embodiment.

[0128] The dual-function module includes a thermal coupling submodule and a mechanical coupling submodule. The thermal coupling submodule transfers the thermoacoustic heat pump effect to the ammonia water through the heat exchange wall to achieve temperature regulation. The mechanical coupling submodule transfers the acoustic flow effect to the ammonia water through a flexible coupling element to achieve circulation drive. This module corresponds to the function in step S102.

[0129] The power determination module is used to determine the target power value based on the target temperature information and the current temperature information. It includes a mapping relationship query submodule and a weighted optimization submodule. This module corresponds to the function in step S103.

[0130] The power regulation execution module is used to regulate the electrical power to the target electrical power value and execute the upper and lower power limit constraints. This module corresponds to the function in step S104.

[0131] The frequency adaptive module is used to track the resonant frequency drift of the thermoacoustic working cavity and adjust the driving frequency. This module corresponds to the function in step S105.

[0132] like Figure 7 As shown, an embodiment of the present invention provides an electronic device, including a memory, a processor, a communication interface, and a bus system.

[0133] The memory is used to store program instructions and running data, including the electric power-thermoacoustic effect mapping table, PID control parameters, weighted optimization parameters, minimum power threshold, historical data of resonant frequency, etc.

[0134] The processor is connected to the memory via a bus and is configured to read and execute program instructions to implement the steps of the temperature control method described above. The processor can be a digital signal processor, a microcontroller, or an industrial PLC.

[0135] The communication interface is used to acquire measurement data from temperature sensors, flow rate sensors, and pressure sensors, and to output power control commands and frequency control commands to the power amplifier.

[0136] like Figure 8 As shown, this embodiment of the invention provides an ammonia water preparation device. The device includes a dissolving and mixing unit and a temperature control system. The dissolving and mixing unit includes a dissolving tank, an ammonia gas inlet pipe, and a pure water inlet pipe.

[0137] The ammonia water circulation loop of the temperature control system is connected to the dissolving tank. Ammonia water flows out from the bottom of the dissolving tank, and after being regulated by the thermoacoustic temperature control section (including the thermoacoustic working cavity section and its heat exchange wall and flexible coupling element) in the circulation loop, it flows back from the top of the dissolving tank. At the same time, the circulation flow maintained by the acoustic-fluid coupling ensures the uniform mixing of the solution concentration.

[0138] In the thermoacoustic working chamber of the temperature control system, the heat exchanger section (low-temperature side) that comes into thermal contact with ammonia water is located in the ammonia water passage of the circulating loop; the heat exchanger section (high-temperature side) that comes into thermal contact with the external heat dissipation loop is connected to the plant's circulating cooling water system or outdoor finned radiators via metal pipes. In the scenario of ammonia water preparation for denitrification in thermal power plants, the existing circulating cooling water of the power plant can be used as the heat dissipation medium for the thermoacoustic heat pump, eliminating the need for additional heat dissipation facilities.

[0139] In some embodiments, the ammonia preparation device is used in the denitrification system of a thermal power plant to prepare ammonia water with a mass concentration of 20% to 25% as a reducing agent for SCR denitrification. The process requires the ammonia water temperature to be maintained within the range of 20°C to 40°C, and the circulation flow rate to meet the requirements for homogenization. The thermoacoustic temperature control system with no moving parts eliminates the risk of seal failure of traditional circulating pumps in an ammonia environment.

[0140] In some embodiments, the ammonia preparation apparatus is used for preparing cleaning solutions in semiconductor manufacturing. The ammonia flow path, with no moving parts, avoids metal particle contamination from mechanical pumps, and the absence of dynamic seals eliminates the impact of ammonia leakage on the cleanroom environment.

[0141] The various embodiments of this invention can be freely combined as needed. The computer program product of this invention includes a computer-readable storage medium storing program code, and the instructions contained in the program code can be used to execute the above-described methods. The storage medium can be a non-transitory storage medium, including flash memory, hard disk, optical disk, etc.

[0142] The sequence numbers of the steps in this invention are for ease of description only and are not intended to limit the order in which the steps are executed. Specifically, the resonant frequency adaptive tracking in step S105 can be executed in parallel with steps S103 and S104.

[0143] The above description is merely a specific embodiment of the present invention. All equivalent substitutions and improvements made based on the technical solution of the present invention should fall within the protection scope of the present invention. For example, replacing the linear motor driven transducer with a piezoelectric ceramic driven or magnetostrictive driven transducer, replacing the helium working fluid with nitrogen or argon, replacing the wire mesh stack regenerator with a parallel plate regenerator, replacing the metal bellows flexible coupling with an elastic diaphragm coupling, and replacing PID control with fuzzy control or model predictive control are all equivalent substitutions that do not depart from the core concept of the present invention.

Claims

1. A temperature control method for an ammonia water preparation device based on thermoacoustic effect, characterized in that, include: Electrical power is input to the electrically driven thermoacoustic converter device installed in the ammonia water circulation loop to establish an oscillating heat flow in the ammonia water circulation loop; The temperature of ammonia in the ammonia circulation loop is regulated by the thermoacoustic heat pump effect of the oscillating heat flow, and the ammonia is driven to circulate in a directional manner in the ammonia circulation loop by the acoustic flow effect of the oscillating heat flow. The target power value is determined based on the target temperature information and the current temperature information of the ammonia water; The electrical power input to the thermoacoustic conversion device is adjusted to the target electrical power value, so as to simultaneously regulate the temperature regulation rate and circulation flow rate by controlling the thermoacoustic oscillation intensity; The temperature regulation and the directional circulation flow are simultaneously achieved through the same oscillating heat flow established by the thermoacoustic conversion device. The fluid passage in the ammonia water circulation loop that comes into contact with the ammonia water is a static fluid passage without mechanical moving parts or dynamic sealing structures. Determining the target electrical power value based on the target temperature information and the current temperature information of the ammonia water includes: using electrical power-thermoacoustic effect mapping information, and based on the temperature deviation between the target temperature information and the current temperature information, determining the target electrical power value that makes the temperature deviation tend to zero. The electrical power-thermoacoustic effect mapping information includes: the correspondence between the electrical power input value and the thermoacoustic oscillation intensity, and the mapping relationship between the thermoacoustic oscillation intensity and the temperature regulation capability.

2. The method as described in claim 1, characterized in that, The step of determining the target power value based on the target temperature information and the current temperature information of the ammonia water further includes: Obtain the current circulation flow rate information and target circulation flow rate information of the ammonia water; The target electrical power value is determined using a weighted optimization strategy based on the temperature deviation and flow rate deviation. The weighted optimization strategy includes: constructing an optimization function with the sum of temperature deviation weighting terms and flow rate deviation weighting terms as the objective, and determining the electric power value corresponding to the minimum value of the optimization function as the target electric power value; When there is a conflict between the power demand corresponding to the temperature deviation and the power demand corresponding to the flow rate deviation, it is determined that the power demand corresponding to the main process objective should be satisfied first according to the preset process priority weighting factor.

3. The method as described in claim 1, characterized in that, The step of inputting electrical power into the electrically driven thermoacoustic converter device disposed in the ammonia water circulation loop to establish an oscillating heat flow in the ammonia water circulation loop includes: The acoustic resonant frequency of the thermoacoustic working cavity section in the ammonia water circulation loop is used as the driving frequency of the electric power to drive the thermoacoustic conversion device to work at the resonant frequency to establish the oscillating heat flow. The method further includes: If the acoustic resonant frequency drifts due to changes in the concentration and / or temperature of the ammonia solution, the driving frequency is adaptively adjusted to track the drift of the acoustic resonant frequency and maintain the resonant operating state. The adaptive adjustment includes: by monitoring the sound pressure amplitude response of the oscillating heat flow, determining the frequency corresponding to the current maximum sound pressure amplitude as the updated acoustic resonant frequency.

4. The method as described in claim 1, characterized in that, The method of using the acoustic flow effect of the oscillating heat flow to drive the ammonia water to directional circulate in the ammonia water circulation loop includes: The ammonia water circulation loop is provided with an asymmetric acoustic structure, which causes the oscillating heat flow to generate a time-averaged net flow in a single direction in the ammonia water circulation loop. The method further includes: If the target electrical power value is lower than the minimum power threshold required to maintain effective thermoacoustic oscillation, it is determined that the electrical power will be maintained at the minimum power threshold in order to maintain the stability of the oscillating heat flow and the continuity of the directional circulating flow.

5. The method as described in claim 1, characterized in that, The ammonia water circulation loop includes a regenerator section and a heat exchanger section; The method of regulating the temperature of ammonia in the ammonia circulation loop by utilizing the thermoacoustic heat pump effect of the oscillating heat flow includes: When the oscillating heat flow passes through the regenerator section, it generates net heat transport along the oscillation direction through the periodic compression and expansion of the fluid micro-elements in the regenerator section and the reciprocating heat exchange with the solid matrix of the regenerator section, thus establishing a temperature difference at both ends of the regenerator section. The heat exchanger section transfers the heat corresponding to the temperature difference to the ammonia water or extracts heat from the ammonia water, thereby achieving the heating or cooling of the ammonia water.

6. A temperature control system for an ammonia water preparation apparatus, characterized in that, The method described in any one of claims 1 to 5 includes: The ammonia water circulation loop is used to contain and guide the circulation flow of ammonia water. The fluid passage part in the ammonia water circulation loop that comes into contact with ammonia water is a static fluid passage without mechanical moving parts or dynamic sealing structure. An electrically driven thermoacoustic conversion device is disposed in the ammonia water circulation loop and is used to establish an oscillating heat flow in the ammonia water circulation loop under the drive of electric power. The oscillating heat flow regulates the temperature of the ammonia water through the thermoacoustic heat pump effect and drives the ammonia water to circulate in a directional manner in the ammonia water circulation loop through the acoustic flow effect. An electric power adjustment unit is used to determine a target electric power value based on the target temperature information and current temperature information of the ammonia water, and adjust the electric power input to the thermoacoustic conversion device to the target electric power value to control the intensity of thermoacoustic oscillation; The temperature regulation and the directional circulating flow are simultaneously achieved through the same oscillating heat flow established by the thermoacoustic conversion device; the electric power regulation unit uses electric power-thermoacoustic effect mapping information to determine the target electric power value based on the temperature deviation between the target temperature information and the current temperature information; the electric power-thermoacoustic effect mapping information includes: the correspondence between the electric power input value and the thermoacoustic oscillation intensity, and the mapping relationship between the thermoacoustic oscillation intensity and the temperature regulation capability.

7. The system as described in claim 6, characterized in that, The thermoacoustic conversion device is any one of a linear motor driven transducer, an electric loudspeaker driven transducer, or a piezoelectric ceramic driven transducer. The ammonia water circulation loop includes a regenerator section and a heat exchanger section. The regenerator section is used to generate net heat transport along the oscillation direction under the action of the oscillating heat flow, and the heat exchanger section is used to exchange heat between the ammonia water and an external heat source or cold source. The ammonia water circulation loop is also provided with an asymmetric acoustic structure, which is used to generate a time-averaged net flow in a single direction to achieve the directional circulation flow. The system also includes a temperature sensor and a flow rate sensor, which are used to acquire the current temperature information and the current circulation flow rate information, respectively, and feed them back to the power regulation unit.

8. An electronic device, characterized in that, include: Memory; And a processor coupled to the memory, the processor being configured to perform the method as described in any one of claims 1 to 5 based on instructions stored in the memory.

9. An ammonia water preparation apparatus, characterized in that, include: The dissolution and mixing unit is used to mix ammonia gas with water to prepare ammonia water; The temperature control system of the ammonia preparation apparatus as described in claim 6 or 7, wherein the ammonia circulation loop of the temperature control system is connected to the dissolution and mixing unit, and is used to regulate the temperature and drive the circulation of the ammonia in the dissolution and mixing unit.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method as described in any one of claims 1 to 5.

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