A semiconductor refrigeration preservation system and method for a buoy nutrient salt analyzer

Abstract

The application provides a buoy nutrient salt analyzer semiconductor refrigeration system and method, comprising: a modular refrigeration reagent bin, a reagent containing cavity with a heat preservation structure; a distributed thermoelectric refrigeration array composed of multiple semiconductor refrigeration pieces, the cold end of which is connected with a cold end heat exchanger, and the hot end is connected with a hot end heat exchanger; a closed circulation pipeline system, which is connected with the hot end heat exchanger and the underwater heat exchanger, and is connected with the heat exchange coil in the reagent bin and the cold end heat exchanger; an adjustable voltage power supply, which provides continuous and stable direct current voltage to the semiconductor refrigeration piece; a sensor, which collects environmental temperature parameters; a controller, which sends a control signal to the adjustable voltage power supply to dynamically adjust the output voltage according to the sensor signal, and performs intermittent refrigeration control based on a preset temperature threshold. The application is designed in cooperation with deep sea water cooling through distributed low current driving, the temperature difference of the refrigeration piece is locked in the high energy efficiency area, and the motionless component architecture is adopted to adapt to the harsh sea conditions.

Description

Technical Field

[0001] This invention relates to the field of refrigeration equipment and systems, and in particular to a semiconductor refrigeration and cold preservation system and method for a buoy nutrient analyzer. Background Technology

[0002] Marine in-situ nutrient analyzers are core equipment for global climate change research, marine biogeochemical cycle monitoring, and nearshore environmental pollution early warning. They automatically complete underwater sampling, reagent mixing, colorimetric reaction, and photoelectric detection to achieve long-term continuous monitoring of key elements such as nitrates, nitrites, phosphates, and silicates. Wet chemical analysis based on national standard protocols offers advantages such as high precision, low detection limits, and strong anti-interference in complex marine environments. However, it is highly dependent on the physicochemical stability of active reagents; reagents must be strictly stored at a constant temperature of 2-8℃, otherwise they will prematurely deactivate, leading to nonlinear shifts in the calibration curve and serious measurement errors. Currently, the original reagent compartments of such analyzers worldwide lack active refrigeration. In low- and mid-latitude seas or during summer conditions, the lack of temperature control in the design causes rapid reagent deactivation, failing to meet the long-term deployment requirements of tropical and subtropical seas.

[0003] On offshore buoys or platforms, traditional compressor systems rely on lubricating oil circulation and stable refrigerant flow. However, in severe sea conditions such as typhoons, the buoy's violent multi-axial swaying can prevent the lubricating oil from returning due to gravity imbalance, leading to dry friction burnout of mechanical components and irreversible system failure. Therefore, the only feasible non-compressor cooling method is semiconductor cooling. However, existing semiconductor cooling solutions mostly use air cooling, which easily generates heat accumulation at the hot end under high temperatures. Excessive temperature difference between the hot and cold ends causes a sharp drop in cooling efficiency, requiring the system to operate continuously under overload, resulting in a surge in energy consumption. Simultaneously, high-speed fans are highly susceptible to salt deposition, scaling, and corrosion in the high-salt-spray, high-humidity marine atmosphere, becoming the most vulnerable link in the long-term operation of the system.

[0004] In addition, offshore buoys are typical "energy islands," with extremely high maintenance costs in the open ocean. High energy consumption operation leads to frequent starting of diesel generators, increasing mechanical wear and the risk of failure.

[0005] To address the aforementioned issues, this invention proposes a cold-insulated reagent storage system capable of adapting to extreme operating conditions of marine buoys. By eliminating the need for easily damaged compressors and fans, it solves the heat dissipation problem of semiconductor cooling chips in high-temperature environments, reducing system energy consumption and enabling long-term unattended monitoring of nutrient analyzers in tropical and subtropical seas. Summary of the Invention

[0006] To address the problems existing in current semiconductor cooling solutions for marine buoys, this invention provides a semiconductor cooling and cold preservation system and method for a buoy nutrient analyzer.

[0007] According to one objective of the present invention, the present invention provides a modular cold-insulated reagent compartment system for a marine buoy nutrient analyzer, comprising:

[0008] A modular cold-insulating reagent compartment has a reagent-containing cavity inside. The cold-insulating reagent compartment has a heat-insulating structure and a heat exchange coil inside.

[0009] A thermoelectric cooling array is composed of one or more semiconductor cooling chips, each of which has a cold end connected to a cold end heat exchanger and a hot end connected to a hot end heat exchanger.

[0010] The system includes a cold water circulation pipeline and a heat dissipation circulation pipeline. The heat dissipation circulation pipeline is connected in sequence to the hot end heat exchanger and an underwater heat exchanger for deployment at a predetermined depth underwater. The cold water circulation pipeline is connected in sequence to the cold end heat exchanger and the heat exchange coil. Both the cold water circulation pipeline and the heat dissipation circulation pipeline are equipped with circulation pumps.

[0011] An adjustable power supply, whose power output terminal is electrically connected to the thermoelectric cooling array, is used to provide a continuous and stable DC voltage to the semiconductor cooling chip;

[0012] A sensor is installed on the cold water circulation pipe or the heat dissipation circulation pipe to collect the temperature parameters of the circulating medium.

[0013] The controller has its input terminal connected to the sensor and its output terminal connected to the control input terminal of the adjustable power supply. The controller sends a control signal to the adjustable power supply according to the signal from the sensor to dynamically adjust the output voltage and performs intermittent cooling control based on a preset temperature threshold.

[0014] Preferably, the adjustable power supply is an adjustable switching power supply, and the control signal is an analog voltage signal.

[0015] Preferably, the circulating pump is a sealless magnetic drive pump, and the underwater heat exchanger is a metal heat exchange tube.

[0016] Preferably, the cold water circulation pipeline or the heat dissipation circulation pipeline is further provided with a buffer water tank for temporarily storing the circulating water. The buffer water tank is connected in series in the pipeline, and the sensor is deployed in the buffer water tank or the circulation pipeline.

[0017] The inlet and outlet of the buffer tank are respectively located at its top and bottom, with the inlet located below the surface of the circulating water.

[0018] Preferably, the modular cold-insulating reagent compartment includes a general-purpose cold-insulating compartment body and a customized interface module;

[0019] The bottom interface size and sealing structure of the customized interface module are designed to be replaceable.

[0020] Preferably, the cold reagent compartment is equipped with a reagent rack that can be pulled out as a whole, and the reagent rack is connected to the cold reagent compartment by a detachable interface.

[0021] Preferably, the system further includes a satellite data acquisition and communication module, which is connected to the controller and is used to remotely transmit the collected temperature parameters and system operating status data to the ground receiving end, and to receive remote control commands to perform start-up and shutdown operations on the thermoelectric cooling array and / or the circulating pump, as well as modify the preset temperature threshold.

[0022] A refrigeration control method based on the above system is also provided, comprising the following steps:

[0023] The temperature parameters of the circulating medium are collected in real time by sensors;

[0024] Preset the upper and lower limits of the target temperature;

[0025] When the detected actual temperature reaches or exceeds the upper limit value, the controller sends a control signal to the adjustable power supply, causing the adjustable power supply to output a continuous DC voltage, driving the thermoelectric cooling array to start cooling, and simultaneously starting the circulation pump.

[0026] During the cooling process, the controller adjusts the amplitude of the control signal in real time according to the temperature change trend to change the voltage output to the semiconductor cooling chip;

[0027] When the detected actual temperature drops to or below the lower limit value, the controller shuts off the output of the adjustable power supply, causing the thermoelectric cooling array to stop cooling.

[0028] Repeat the steps above.

[0029] Preferably, the upper limit is 7°C and the lower limit is 5°C.

[0030] Preferably, the control signal is an analog voltage signal of 0-5V;

[0031] The amplitude of the continuous DC voltage output by the adjustable power supply changes accordingly based on the amplitude of the control signal.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] This invention, through the synergistic design of a distributed low-current drive matrix and a deep-seawater cooling circuit, locks the temperature difference between the two ends of the semiconductor refrigeration chip within a high-efficiency linear region, significantly improving the cooling energy efficiency ratio and reducing system energy consumption.

[0034] This invention uses a shaftless magnetic drive pump to replace the traditional compressor and cooling fan, realizing the physical staticization of the refrigeration system, greatly reducing mechanical wear points and motion failure points, and can withstand strong typhoon vibrations, high-frequency turbulence and large-angle tilting conditions, ensuring structural stability and continuous operation under complex sea conditions.

[0035] This invention utilizes a pressure-position mode composite control algorithm based on thermal inertia to transform the traditional continuous high-frequency operation into an intermittent, low-current, high-efficiency working mode by taking advantage of the high specific heat capacity of the reagent itself. This significantly reduces system energy consumption and extends the service life of power components.

[0036] This invention employs a modular, cold-insulated reagent compartment structure, expanding reagent storage capacity and directly matching the long-term unattended monitoring cycle at sea. Through a combination of a universal cold-insulated compartment and customized interface modules, it achieves in-situ compatibility with multiple brands of analyzers without altering the original main structure of mainstream nutrient analyzers. Simultaneously, the reagent rack features a fully removable design, enabling rapid replenishment and batch replacement of reagents without interrupting the cooling circulation pipeline, thus shortening on-site operation time in extreme marine environments.

[0037] This invention effectively suppresses the activity decay of reagents during storage through precise active temperature control, ensuring the rigor and scientific nature of marine monitoring data.

[0038] This invention also integrates a satellite communication module, which supports real-time monitoring of system operating parameters and can dynamically adjust the temperature control threshold through remote commands, thus realizing fully remote intelligent control of the system.

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0040] Figure 1 This is an overall schematic diagram of a modular cold-insulated reagent compartment system for a marine buoy nutrient analyzer as described in this invention;

[0041] Figure 2 This is a cross-sectional schematic diagram of the cold reagent compartment in the modular cold reagent compartment system of the marine buoy nutrient analyzer described in this invention;

[0042] Figure 3 This is a schematic diagram of the overall cold reagent compartment in the modular cold reagent compartment system of the marine buoy nutrient analyzer described in this invention;

[0043] Figure 4 This is a schematic diagram of a distributed thermoelectric refrigeration array in a modular cold-insulating reagent storage system for a marine buoy nutrient analyzer as described in this invention.

[0044] Figure 5This is a schematic diagram of the interior (integrated support frame) of the buoy compartment in the modular cold-insulated reagent compartment system of the marine buoy nutrient analyzer described in this invention;

[0045] Figure 6 This is a schematic diagram of the external part (mooring rack) of the modular cold-insulated reagent tank system for a marine buoy nutrient analyzer described in this invention. Detailed Implementation

[0046] The following description is intended to provide a detailed account of the invention so that those skilled in the art can implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0047] This embodiment provides a modular cold-insulated reagent compartment 100 system for marine buoy nutrient analyzers. This system solves the industry gap of energy efficiency collapse, data drift and poor survivability of in-situ monitoring equipment in extreme marine environments by constructing a deep integrated architecture of "utilizing natural cold sources in deep seawater" and "TEC pressure regulation linkage refrigeration-cold storage".

[0048] See Figures 1 to 3 The system includes a modular cold reagent compartment 100, which has a reagent holding cavity inside. The cold reagent compartment 100 has a thermal insulation structure. In a preferred embodiment, the compartment structure is a double-layer sandwich shell 101 made of PVC material. The double-layer sandwich shell 101 includes an inner shell 106 and an outer shell 107. A core layer is provided between the inner shell 106 and the outer shell 107. The core layer is filled with a 20mm thick high-density polyurethane foam material 102. The outer surface of the compartment is coated with a high-reflectivity infrared reflective layer and an anti-salt spray fluorocarbon coating. The cold reagent compartment 100 also includes a waterproof and thermally insulated cover 104. The waterproof and thermally insulated cover 104 is closable and connected to the end of the double-layer sandwich shell 101. The inner side of the waterproof and thermally insulated cover 104 also has a thermal insulation structure. See [link to relevant documentation]. Figure 2 The insulation layer 105 in the insulation cover not only effectively shields against heat radiation exceeding 40°C at sea, but also utilizes the thermal inertia of a large-capacity reagent and 5L of cooling water to construct a "cold storage physical buffer pool," providing a stable physical carrier for the subsequent intermittent cooling logic of the "pressure regulation-position mode." Furthermore, this system increases the reagent storage space to more than six times the original built-in volume of the analyzer. This design directly matches the 3-4 month continuous unattended monitoring cycle at sea, resolving the core contradiction between long-cycle monitoring tasks and limited reagent storage capacity from a physical capacity perspective.

[0049] See Figure 1 and 4The system also includes a distributed thermoelectric cooling array 200, composed of multiple thermoelectric coolers 201. The cold end of each thermoelectric cooler 201 is connected to a cold-end heat exchanger 202, which is thermally coupled to the cold reagent chamber 100. The hot end is connected to a hot-end heat exchanger 203. In a preferred embodiment, the cooling module 204 uses a distributed array layout consisting of eight thermoelectric coolers 201, each with a power of 18W. The system is designed with a total power reserve of 144W, with actual operation requiring only approximately 90W in summer and 30W in winter. This distributed structure possesses strong redundancy and resilience. Even in harsh conditions where up to three thermoelectric coolers fail unexpectedly, the remaining five coolers can still maintain effective cooling through dynamic voltage adjustment, ensuring the continuity of monitoring tasks during unmanned operations at sea. The cold reagent compartment 100 is equipped with a heat exchange coil 108, which has a heat exchange coil inlet 109 and a heat exchange coil outlet 110. The heat exchange coil inlet 109 is connected to the outlet of the cold end heat exchanger 202, and the heat exchange coil outlet 110 is connected to the inlet of the cold end heat exchanger 202.

[0050] The system also includes an adjustable power supply, whose power output terminal is electrically connected to the distributed thermoelectric cooling array 200, for providing a continuous and stable DC voltage to the thermoelectric cooler 201. In a preferred embodiment, the adjustable power supply is an adjustable switching power supply, and the control signal is an analog voltage signal. Specifically, the hardware structure is centered on the adjustable switching power supply, with external sensors and a microcontroller unit (MCU). The control output terminal of the MCU is connected to the control input terminal of the adjustable switching power supply, for sending a 0-5V analog control signal to it; the power output terminal of the adjustable switching power supply is connected to the thermoelectric cooler 201 (TEC), for providing a smooth DC voltage of a specific amplitude to the TEC. Traditional solutions use a fixed 24V voltage combined with pulse width modulation (PWM) technology, adjusting the duty cycle to output an equivalent voltage (e.g., 50% duty cycle equivalent to 12V). However, since the Joule heat of semiconductor components is proportional to the square of the current, the high-amplitude peak current in the square wave waveform generates instantaneous Joule heat at the moment of conduction, resulting in high overall useless heat loss and low cooling efficiency. To address the aforementioned technical issues, the MCU of this invention calculates the required cooling power based on the air and water temperature data fed back by the sensors, and sends a corresponding 0-5V analog signal to the adjustable switching power supply. The adjustable switching power supply responds to the analog signal, dynamically adjusting and outputting a continuous and stable DC voltage amplitude (e.g., a steady-state 12V DC voltage) that matches the required power. Since the current output to the TEC is a constant and continuous DC current, the peak current heating caused by square wave pulses is eliminated. Under the premise of providing the same cooling power, the Joule heating generated by the TEC itself due to the current square effect is significantly reduced, thus reducing system energy consumption and improving the cooling energy efficiency ratio.

[0051] See Figure 1 The system comprises two independent closed-loop circulation systems: a cold water circulation pipeline 307 and a heat dissipation circulation pipeline 308. The heat dissipation circulation pipeline is sequentially connected to the hot-end heat exchanger 203 and an underwater heat exchanger 302 deployed at a predetermined depth underwater, used to carry the heat from the hot-end heat exchanger 203 to the deep seawater for dissipation. The cold water circulation pipeline is sequentially connected to the cold-end heat exchanger 202 and a heat exchange coil 108 disposed inside the cold-insulating reagent chamber 100, used to transport the cooling capacity generated by the cold-end heat exchanger 202 to the cold-insulating reagent chamber 100. Both the cold water circulation pipeline and the heat dissipation circulation pipeline are equipped with circulation pumps 300. The circulation pipelines can be made of silicone rubber and filled with a circulating medium.

[0052] In a preferred embodiment, the circulating pump is a seal-free magnetically driven pump, and the underwater heat exchanger is a metal heat exchange tube. Specifically, the underwater heat exchanger is a copper heat exchange tube deployed at a depth of 15-25 meters below the sea surface. The circulating medium is ultrapure water, with trace amounts of 1227 bactericide (dodecyl dimethyl benzyl ammonium chloride) and a small amount of defoamer (1 / 10,000) added to inhibit microbial growth, prevent slime formation, and eliminate bubbles, respectively. Because the system is completely closed, the circulating medium does not volatilize, and no additional liquid replenishment is required during operation. The underwater heat exchange copper tube is made entirely of copper, utilizing the natural antibacterial properties of copper ions to prevent marine organisms from adhering to the surface. In actual maintenance, the underwater heat exchange copper tube only needs to be brought to the surface for surface cleaning every preset maintenance cycle (e.g., 3 months). The heat exchange coil 108 inside the reagent compartment is made of 316L stainless steel. This architecture achieves physical staticization of the refrigeration system, significantly reducing mechanical wear points and motion failure points, and providing up to 20,000 hours of maintenance-free time, ensuring structural stability and operational continuity under complex sea conditions.

[0053] The technical effects of this invention and its comparison with traditional air-cooling methods are as follows: In an environment where the surface seawater temperature is 28°C in summer, the underwater heat exchange copper pipe deployed 20 meters below the sea surface can maintain the water temperature in the heat dissipation circulation pipeline at 22°C. When the target cooling temperature is set at 5°C, the actual heat exchange temperature difference between the two ends of the TEC is only 17°C. This temperature difference is within the TEC's high-efficiency cooling linear range, which can meet the high-efficiency cooling requirements in summer. In contrast, in traditional air-cooling solutions, the extreme temperature inside the buoy cabin can reach as high as 48°C in summer. At this temperature, a large heat exchange temperature difference exceeding 40°C will cause difficulty in heat dissipation at the hot end of the TEC, resulting in a significant decrease in cooling efficiency.

[0054] As a preferred embodiment, see [link to preferred embodiment]. Figure 1 and 5 A buffer tank 301 is also provided on the cold water circulation pipeline. The buffer tank is connected in series in the cold water circulation pipeline and is used to temporarily store circulating water. The inlet and outlet of the buffer tank are respectively located at its top and bottom. Specifically, the buffer tank adopts a tall and narrow configuration and uses a top-inlet and bottom-outlet flow path design to allow for self-venting of air bubbles, thereby effectively eliminating air bubbles generated by pressure fluctuations and reducing cavitation caused by air bubbles entering the magnetic pump and affecting the pump impeller. In addition, under high sea state swaying conditions, as long as the tilt angle does not exceed 50°, the water inlet at the bottom of the buffer tank is always located below the circulating water surface, preventing air from entering the submersible pump and causing airlock. The buffer tank also provides thermal inertia buffer for the system, which, together with the on-off control, significantly reduces the start-stop frequency of the power components and extends the service life of the equipment. In this embodiment, the circulation pump is built into the buffer tank, and the circulation pump is a submersible magnetic pump.

[0055] The system also includes sensors to collect ambient temperature parameters. Specifically, the sensors are used to detect the current ambient air and water temperature signals in real time and transmit the signals to the MCU.

[0056] The system also includes a controller, whose input is connected to the sensor and whose output is connected to the control input of the adjustable power supply. The controller sends control signals to the adjustable power supply based on the sensor signals to dynamically adjust the output voltage and performs intermittent cooling control based on a preset temperature threshold. In a preferred embodiment, the controller is a microcontroller unit (MCU), which serves as the control brain of the entire system, responsible for closed-loop control: first, it reads analog / digital signals such as air temperature and water temperature transmitted from the sensor; then, it runs a control algorithm internally to calculate the most reasonable cooling power; finally, it converts this into a 0-5V analog control signal and sends it to the adjustable switching power supply in real time.

[0057] In a preferred embodiment, the modular cold-insulating reagent compartment 100 includes a universal cold-insulating compartment body and a customized interface module; the bottom interface size and sealing structure of the customized interface module are designed to be replaceable. Specifically, the cold-insulating reagent compartment 100 adopts a modular and in-situ adaptable design in its structure. Without changing the original main structure of mainstream nutrient analyzers (such as WIZ, Clearwater, etc.), seamless in-situ compatibility is achieved through customized fine-tuning of the bottom interface. The cold-insulating reagent compartment 100 is composed of a universal cold-insulating compartment body and a customized interface module. The universal cold-insulating compartment body has a standardized reagent containing chamber, thermoelectric cooling (TEC) components, and the aforementioned deep seawater cooling circuit. Its core electrical control and temperature control logic remain consistent, forming a standardized module. The fluid and physical interfaces at the bottom of the compartment body adopt a discrete orifice array layout to match the inlet and outlet pipelines of the analyzer. Specific physical interface parameters (such as the outer diameter of the slot, the diameter of the fluid orifice distribution circle, and the position of the positioning pin hole) are designed with equal-dimensional mapping based on the original reagent compartment base standard of the analyzer to be adapted. Addressing the differences in mechanical clamping methods and sealing forms between different manufacturers or models of analyzers, this invention achieves precise adaptation by fine-tuning the geometric dimensions of the outlet end face and replacing the sealing element type, eliminating the need for complex independent adapter modules and maintaining high structural reliability: for instruments using high-pressure local sealing, an annular mounting groove for accommodating O-rings is machined inside the outlet; for instruments using surface-contact low-pressure sealing, the outlet end face is adjusted to a smooth configuration for fitting a planar sealing gasket. Through the above modular and interface fine-tuning design, the cold reagent compartment 100 of this invention can directly replace the non-cold reagent compartment 100 of the original instrument in extreme conditions such as marine buoys.

[0058] As a preferred embodiment, see [link to preferred embodiment]. Figure 2The cold reagent compartment 100 is equipped with a reagent rack 103 that can be completely removed. The reagent rack 103 is connected to the cold reagent compartment 100 via a detachable interface. Specifically, the outer shell 107 of the cold reagent compartment 100 and the internal reagent rack 103 adopt a standardized universal interface design. A fixing rod 111 is provided in the middle of the reagent rack 103. The reagent compartment interface is inserted into the instrument host and fixed by the central fixing rod 111. When the chemical reagents in the compartment are depleted and need to be replenished, maintenance personnel do not need to disassemble the entire cold reagent compartment 100 or disconnect the cooling circulation pipeline. They only need to pull the reagent rack 103 out from the outer shell 107 as a whole, and then push in a standardized reagent rack 103 of the same specification pre-loaded with freshly prepared reagents and lock it in place to complete the rapid replenishment and batch replacement of reagents. This process greatly shortens the on-site operation time in extreme marine environments and improves the in-situ maintenance convenience of the buoy system.

[0059] This invention also provides a refrigeration control method based on the above system. The control algorithm of this invention organically combines "on-off switching control" with "dynamic voltage regulation (voltage adjustment)". "On-off mode" refers to on-off control (or dual-position control, switch control), the core feature of which is setting a target temperature range consisting of an upper temperature limit and a lower temperature limit. When the temperature of the controlled medium reaches or exceeds the upper limit, the control system drives the refrigeration circuit to start; when the temperature drops to the lower limit, the control system drives the refrigeration circuit to stop; within the range between the upper and lower limits, the system state remains stable or is in a buffer transition state. This invention chooses on-off control instead of continuous PID control because the deep seawater cooling circuit of this invention integrates power components such as a magnetic circulation pump. If a traditional high-frequency regulation scheme is used, the power components will have their service life severely shortened due to frequent induced electromotive force impacts and mechanical wear caused by frequent switching or operation under excessively low power conditions. Therefore, this invention, through on-off control, combined with a buffer water tank (such as a 5L water tank) installed in the circuit, provides thermal inertia buffering for the system, thereby significantly reducing the start-stop frequency of the power components and extending the service life of the equipment.

[0060] The specific steps of the control method are as follows: Step 1, parameter initialization and range setting: The upper and lower limits of the target temperature are preset in the MCU. As a preferred embodiment, the upper temperature limit is set to 7℃ and the lower temperature limit to 5℃. Step 2, temperature signal acquisition: Ambient temperature parameters are acquired in real time through sensors, specifically through temperature sensors deployed in the buffer tank or circulation pipeline to acquire the actual water temperature of the current cooling circuit. Step 3, on-off state judgment and voltage regulation execution: When the detected actual temperature reaches or exceeds the upper limit, the controller sends a control signal to the adjustable voltage power supply, causing the adjustable voltage power supply to output a continuous DC voltage, driving the distributed thermoelectric cooling array 200 to start cooling, and simultaneously starting the circulation pumps in the cold water circulation pipeline and the heat dissipation circulation pipeline. Specifically, when the detected actual return water temperature is ≥7℃, the system determines that the upper limit is triggered. At this time, the MCU controls the magnetic circulation pump to start, and simultaneously runs the voltage regulation logic: the MCU sends a corresponding 0-5V analog signal to the adjustable voltage switching power supply according to the difference between the current water temperature and the target temperature, dynamically adjusting the DC voltage amplitude output to the TEC, so that the TEC starts cooling with optimal power. Step four: During the cooling process, the controller adjusts the amplitude of the control signal in real time according to the temperature change trend to change the voltage output to the thermoelectric cooler 201. In a preferred embodiment, the amplitude of the continuous DC voltage output by the adjustable power supply changes accordingly based on the amplitude of the control signal. Specifically, during the dynamic process of the actual water temperature continuously decreasing from 7°C to 5°C, the MCU fine-tunes the DC voltage amplitude in real time according to the temperature drop curve to maintain efficient cooling, and the cooling circulation pump remains on. Step five: When the detected actual temperature drops to or below the lower limit, the controller shuts off the output of the adjustable power supply, causing the distributed thermoelectric cooling array 200 to stop cooling. Specifically, when the actual water temperature is ≤5°C, the system determines that the lower limit has been triggered. At this time, the MCU outputs a control signal to shut off the power supply to the TEC, and the system enters a buffer phase of natural temperature recovery. Step six: Repeat the above steps to achieve intermittent cooling control based on thermal inertia. Specifically, until the water temperature rises again to ≥7°C, the system jumps back to the startup phase. Throughout the process, the cooling water circulation pump remains running. This composite logic significantly improves the system's energy efficiency ratio, reducing power consumption by more than 60% compared to traditional monolithic solutions.

[0061] As a preferred embodiment, see [link to preferred embodiment]. Figure 5The internal components of the system are assembled using a three-layer integrated support frame 305. From top to bottom, the first layer houses the electronic control system 303, including a microcontroller unit (MCU) and an adjustable voltage switching power supply; the second layer houses the cooling module 204, including a distributed thermoelectric cooling array 200 composed of eight 18W semiconductor cooling chips 201 and aluminum heat exchange fins; the third layer houses a 5L buffer water tank 301 with a built-in magnetic circulation pump. The exterior of the three-layer support frame is wrapped with a polyurethane foam insulation layer with a thickness of not less than 30mm to prevent heat exchange with the ambient air inside the buoy cabin. This skid-mounted structure achieves compact integration of core components and efficient thermal insulation.

[0062] The following detailed description of the assembly, deployment, operation, and maintenance process of the present invention is based on a specific embodiment. Step one: Skid-mounted module assembly and integrated thermal insulation frame mounting: Four mounting and positioning holes with a diameter of Φ12mm are opened on the bottom surface of the three-layer integrated bracket 305 to achieve rapid positioning and rigid installation within the buoy compartment. The core refrigeration cycle components of the system (including the microcontroller unit MCU, adjustable voltage switching power supply, TEC array composed of eight 18W semiconductor cooling chips 201, aluminum heat exchange plates, and magnetic circulation pump) are uniformly assembled and fixed on the three-layer integrated frame to form a portable small skid-mounted structure. All exposed non-heat exchange surfaces that experience temperature differences during operation, including the sides of the TEC array and the non-adhesive surfaces of the aluminum heat exchange plates, are entirely coated with a polyurethane foam layer with a thickness of not less than 30mm to block heat exchange with the ambient air inside the buoy compartment; while the cold water magnetic circulation pump and 5L water tank are placed in a high-density flame-retardant insulation box with a wall thickness of 4cm. Step Two, Rigid Fixing and Anti-Loosening Seismic Deployment Inside the Buoy: A steel base is welded and fixed to the internal floor of the buoy hull, and four M8×1.5 bolts with a height of 30mm are vertically welded to the base. The skid-mounted structure assembled in Step One is hoisted onto the fixed base 304, ensuring that the four Φ12mm mounting holes at the bottom of the bracket pass precisely through the corresponding bolts. Then, anti-backflow flange nylon nuts are sequentially inserted and tightened to ensure that the system does not shift under extreme sea conditions and vibrations. The two sets of circulating water pipes (including cold water circulation pipes and heat dissipation circulation pipes) are guided and passed through the pre-reserved penetration holes in the buoy hull wall. After the pipes pass through, rigid polyurethane foam is used to fill and seal the penetration holes to achieve moisture-proof, waterproof, and flood-proof standards. Step 3: High-efficiency thermal insulation and fluid loop connection for pipelines: For Φ12mm silicone circulation pipelines exposed to air above the water surface, an aluminum foil-reinforced nitrile rubber (NBR) insulation pipe with an inner diameter of 13mm and an outer diameter of 53mm is installed on its outer wall to prevent high ambient temperatures from damaging the cooling capacity of the liquid inside the pipe. See also Figure 6The modular cold-insulating reagent compartment 100 and analytical instrument 309 (such as a WIZ analyzer) are integrated and placed on the mooring rack 310, and mechanically fixed using snap-fit ​​fittings 311, which include metal clips and nylon clips. After fixing, the cold water circulation pipeline is connected to the corresponding fluid inlet and outlet of the cold-insulating reagent compartment 100. The inlet and outlet of the heat dissipation circulation pipeline are connected to underwater heat exchange copper pipes with matching outer diameters. Subsequently, the mooring rack is lowered to the safety well and suspended on the water surface, with the heat exchange copper pipes naturally submerged at a depth of 20 meters. Step four, media filling and closed-loop system purification: Before starting the system, the circulating media is filled into the closed-loop circulation system. The circulating media is ultrapure water, with 0.1% concentration of 1227 bactericide added by mass. This ratio, while ensuring the heat capacity of the liquid, can efficiently destroy the cell walls of microorganisms, prevent the formation of biological slime on the inner walls of the pipeline and copper pipes, and ensure that the heat transfer coefficient does not decrease. Step 5, Intelligent Control Start-up and Steady-State Cooling Operation: The buoy power supply system is started, and the control system MCU is powered on. The system reads the current ambient air and water temperature through temperature sensors. Since the initial actual water temperature is ≥7℃, the upper limit threshold is triggered. The MCU controls the magnetic circulation pump to start, and simultaneously outputs a full 5V analog signal to the adjustable switching power supply. The switching power supply then outputs a steady-state continuous DC voltage to drive the TEC array at full power cooling, and the cooling water temperature drops rapidly. When the actual water temperature drops to the target range (e.g., 5~7℃), the MCU switches to maintenance control. Based on the monitored temperature rise curve, the output analog signal is dynamically fine-tuned (e.g., fluctuating between 2.5~4V) to ensure the switching power supply outputs an equivalent steady-state low DC voltage, allowing the system to operate in the high-efficiency linear region. When the 5℃ stop line is reached, the system automatically disconnects the TEC power supply and enters an intermittent buffer phase. Step Six, Periodic Maintenance Process: During the long-term operation of the system at sea, maintenance personnel will use a buoy maintenance window to lift the underwater heat exchange copper pipe, suspended 20 meters below the sea surface, from the safety well every preset period (e.g., every 3 months). A soft brush will be used to physically clean any adhering substances or trace algae on the surface of the copper pipe. After cleaning, the pipe will be lowered back to 20 meters below the sea surface. Because the system is fully enclosed and uses silicone tubing, no water tank replenishment is required during maintenance. Furthermore, when the chemical reagents in the tank are depleted and need to be replenished, maintenance personnel do not need to disassemble the entire cold-insulated reagent compartment 100 or disconnect the cooling circulation pipeline. They only need to pull the reagent rack 103 out of the outer shell 107, then push in a standardized reagent rack 103 pre-loaded with freshly prepared reagents and lock it in place, thus completing rapid replenishment and batch replacement of reagents.

[0063] The system described in this invention achieves the following technical effects, and COP test data shows that:

[0064] In the actual test of the heat box, under summer conditions (air temperature 48.5℃, simulated heat exchange seawater temperature 28℃, target water tank water temperature 5℃), the theoretical energy required is 481kJ (0.134kW·h), the actual electrical energy consumed is 0.220kW·h, and the COP is 0.6.

[0065] Under winter operating conditions (air temperature 12℃, simulated heat exchange seawater temperature 12℃, target water tank water temperature 5℃), the theoretical energy required is 188kJ (0.052kW·h), the actual electrical energy consumed is 0.037kW·h, and the COP is 1.4.

[0066] Regarding cold insulation performance, the refrigeration cycle system described in this invention has been successfully installed on a marine buoy and has been operating continuously for six months. During actual marine environmental operations in autumn, winter, and spring, the system accumulated a series of measured data, including the ambient temperature inside the buoy chamber, seawater temperature, and the temperatures of the refrigerated water outlet and return. Under these actual operating conditions, the highest temperature inside the buoy chamber reached over 30°C, and all core components of the system operated stably, with the cold insulation effect meeting design specifications. Regarding biofouling prevention, the heat exchange copper tubes, when submerged to a depth of 20 meters, exhibited excellent biofouling resistance. After six months of continuous operation, only verdigris appeared on the surface, with no biofouling observed; in contrast, stainless steel showed significant biofouling.

[0067] For remote intelligent control, see [link / reference]. Figure 1 The system of this invention integrates a satellite data acquisition and communication module 306, which is connected to the controller. This module supports real-time monitoring of return water temperature, cabin temperature, and system tilt angle, and dynamically adjusts the temperature control threshold via remote satellite AT commands, achieving optimal dynamic energy allocation when the power system alarms. During actual operation at sea, all data can be remotely transmitted to the ground receiving end via the data acquisition module and satellite; simultaneously, the ground control end can remotely send control commands to execute remote start-up and shutdown operations of the cabin refrigeration equipment (including thermoelectric refrigeration arrays and / or circulating pumps), and can remotely modify the system's target cooling temperature, realizing fully remote intelligent control of the system.

[0068] In summary, this invention, through the synergistic design of a distributed low-current drive matrix and a deep-seawater cooling circuit, locks the temperature difference across the TEC terminals within a high-efficiency linear range, achieving a high energy efficiency ratio (COP) of >0.6 in summer and >1.4 in winter. Through a componentless architecture and a materials-based self-cleaning mechanism, it achieves high reliability, withstanding category 12 typhoons and requiring no maintenance for up to 20,000 hours. The voltage-position mode composite control algorithm based on thermal inertia reduces power consumption by over 60% compared to traditional solutions. Modular adaptation and a quick-release reagent rack (103) design enable in-situ, non-destructive replacement of multi-brand analyzers and rapid reagent replacement. The system has been successfully installed on a marine buoy and has been operating continuously for six months, achieving the designed cooling performance. Actual test reagent shelf life exceeded four months, ensuring the rigor and scientific validity of marine monitoring data.

[0069] The embodiments described above are only used to illustrate the technical ideas and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The scope of patent application of the present invention should not be limited by these embodiments. That is, any equivalent changes or modifications made in accordance with the spirit disclosed in the present invention still fall within the patent scope of the present invention.

Claims

1. A modular cold-insulated reagent compartment system for a marine buoy nutrient analyzer, characterized in that, include: A modular cold-insulating reagent compartment has a reagent-containing cavity inside. The cold-insulating reagent compartment has a heat-insulating structure and a heat exchange coil inside. A thermoelectric cooling array is composed of one or more semiconductor cooling chips, each of which has a cold end connected to a cold end heat exchanger and a hot end connected to a hot end heat exchanger. The system includes a cold water circulation pipeline and a heat dissipation circulation pipeline. The heat dissipation circulation pipeline is connected in sequence to the hot end heat exchanger and an underwater heat exchanger for deployment at a predetermined depth underwater. The cold water circulation pipeline is connected in sequence to the cold end heat exchanger and the heat exchange coil. Both the cold water circulation pipeline and the heat dissipation circulation pipeline are equipped with circulation pumps. An adjustable power supply, whose power output terminal is electrically connected to the thermoelectric cooling array, is used to provide a continuous and stable DC voltage to the semiconductor cooling chip; A sensor is installed on the cold water circulation pipe or the heat dissipation circulation pipe to collect the temperature parameters of the circulating medium. The controller has its input terminal connected to the sensor and its output terminal connected to the control input terminal of the adjustable power supply. The controller sends a control signal to the adjustable power supply according to the signal from the sensor to dynamically adjust the output voltage and performs intermittent cooling control based on a preset temperature threshold.

2. The system according to claim 1, characterized in that, The adjustable voltage power supply is an adjustable voltage switching power supply, and the control signal is an analog voltage signal.

3. The system according to claim 1, characterized in that, The circulating pump is a sealless magnetic drive pump, and the underwater heat exchanger is a metal heat exchange tube.

4. The system according to claim 1, characterized in that, The cold water circulation pipeline or the heat dissipation circulation pipeline is also equipped with a buffer water tank for temporarily storing circulating water. The buffer water tank is connected in series in the pipeline, and the sensor is deployed in the buffer water tank or the circulation pipeline. The inlet and outlet of the buffer tank are respectively located at its top and bottom, with the inlet located below the surface of the circulating water.

5. The system according to claim 1, characterized in that, The modular cold-insulated reagent compartment includes a general-purpose cold-insulated compartment body and a customized interface module; The bottom interface size and sealing structure of the customized interface module are designed to be replaceable.

6. The system according to claim 1, characterized in that, The cold reagent compartment is equipped with a reagent rack that can be pulled out as a whole, and the reagent rack is connected to the cold reagent compartment by a detachable interface.

7. The system according to claim 1, characterized in that, The system also includes a satellite data acquisition and communication module, which is connected to the controller and is used to remotely transmit the collected temperature parameters and system operating status data to the ground receiving end, and to receive remote control commands to perform start-up and shutdown operations on the thermoelectric cooling array and / or the circulating pump, as well as modify the preset temperature threshold.

8. A cooling control method based on the system according to any one of claims 1 to 7, characterized in that, Includes the following steps: The temperature parameters of the circulating medium are collected in real time by sensors; Preset the upper and lower limits of the target temperature; When the detected actual temperature reaches or exceeds the upper limit value, the controller sends a control signal to the adjustable power supply, causing the adjustable power supply to output a continuous DC voltage, driving the thermoelectric cooling array to start cooling, and simultaneously starting the circulation pump. During the cooling process, the controller adjusts the amplitude of the control signal in real time according to the temperature change trend to change the voltage output to the semiconductor cooling chip; When the detected actual temperature drops to or below the lower limit value, the controller shuts off the output of the adjustable power supply, causing the thermoelectric cooling array to stop cooling. Repeat the steps above.

9. The method according to claim 8, characterized in that, The upper limit is 7°C and the lower limit is 5°C.

10. The method according to claim 8, characterized in that, The control signal is an analog voltage signal of 0-5V; The amplitude of the continuous DC voltage output by the adjustable power supply changes accordingly based on the amplitude of the control signal.

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