Photovoltaic-Ice Storage Cooling Environment Control System and Control Method for Dairy Cow Sheds

Abstract

This invention discloses a photovoltaic-ice storage environmental control system and its control method for dairy cow sheds, belonging to the field of intelligent environmental regulation and comprehensive utilization of renewable energy in large-scale livestock and poultry farming. The system includes a power supply end, a cooling and storage end, an air supply end, and a monitoring and control end. The power supply end, including photovoltaic modules on the dairy cow shed roof, drives the cooling and storage end, utilizing the latent heat of phase change of ice to store cold energy. The monitoring and control end dynamically switches between five operating modes based on real-time THI (Heat Stress Index), photovoltaic output, and ice storage capacity. It also incorporates weather forecasts for predictive ice storage scheduling, prioritizing photovoltaic power generation and using surplus electricity for ice making. The cold energy is precisely delivered to the dairy cow activity area via fan coil units. This invention significantly improves renewable energy utilization, reduces grid power consumption, reduces heat stress in dairy cows, and enhances milk production stability. It is suitable for environmental regulation in large-scale dairy cow sheds in high-temperature and high-humidity areas.

Description

Technical Field

[0001] This invention relates to the field of intelligent environmental control and comprehensive utilization of renewable energy in large-scale livestock and poultry farming, specifically to a photovoltaic-ice storage cooling environment control system and its control method for dairy cow sheds. Background Technology

[0002] The sustained high temperature and humidity in summer can easily cause heat stress in dairy cows, leading to a significant decrease in feed intake and feed conversion rate, impaired reproductive performance, and reduced immune function. In severe cases, it can even cause death, directly affecting the breeding safety and economic benefits of large-scale dairy farms. Currently, the commonly used summer environmental control measures in large-scale dairy barns mainly include mechanical ventilation, spray cooling, evaporative cooling pads with negative pressure fans, and air cooler duct cooling. However, none of these methods can simultaneously meet the needs of cooling, humidity control, low energy consumption, and animal welfare in dairy barns in hot and humid areas.

[0003] Existing photovoltaic (PV) + ice storage cooling technologies and systems are mainly used in residential and commercial buildings. Direct application in dairy barn scenarios faces three major technical bottlenecks: First, existing PV-ice storage systems rely on peak-valley electricity price arbitrage, generally employing an "ice-making at night during off-peak hours and ice-melting during daytime peak hours" operating mode. However, the peak heat stress levels in dairy barns and the peak PV output highly overlap during the high-temperature daytime hours. The traditional mode cannot maximize the self-consumption of PV power, instead resulting in ineffective consumption of high-priced daytime peak electricity, failing to simultaneously achieve the dual goals of controlling heat stress in dairy cows and reducing energy costs. Second, the control strategy is disconnected from the physiological needs of dairy cows: existing systems... Using only ambient temperature, electricity price, and photovoltaic output as the sole basis for regulation, without combining it with the core evaluation indicator of dairy cow heat stress—the temperature and humidity index (THI)—for coordinated decision-making, can easily lead to problems such as insufficient cooling causing severe heat stress in dairy cows, or excessive cooling causing energy waste. It is impossible to achieve deep coupling between breeding needs and the cooling system. Third, the terminal system has poor adaptability to the cowshed scenario: the existing air conditioning terminals cannot adapt to the needs of open large spaces and differentiated cooling in different areas of dairy cowsheds. The air delivery targeting is poor, and it is impossible to achieve precise cooling for core activity areas such as cows' beds and feeding areas. The ineffective loss of cooling capacity is serious, which further reduces the energy efficiency and practicality of the system.

[0004] To address the shortcomings of existing technologies, there is an urgent need to develop a photovoltaic-ice storage cooling environment control scheme that adapts to the needs of large-scale dairy farming, maximizes the self-generation and self-consumption of photovoltaic power, and combines precise control with physiological indicators of dairy cow heat stress. This scheme would achieve low-carbon, efficient, and precise prevention and control of dairy cow heat stress without significantly increasing farming costs. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a photovoltaic-ice storage cooling environment control system and its control method for dairy cow sheds. This system solves the technical problems of poor cooling effect, insufficient precision, significant humidity interference, high operating costs, and poor adaptability of photovoltaic-ice storage cooling systems to dairy farming scenarios. It utilizes large-scale idle rooftop resources in dairy cow sheds to install photovoltaic arrays, with the core objective of maximizing self-consumption of photovoltaic power generation. The system uses an ice storage cooling system to store surplus photovoltaic power, replacing traditional high-cost, high-pollution chemical energy storage batteries. A three-dimensional collaborative intelligent control strategy is constructed, prioritizing the dairy cow heat stress index (THI) level, using photovoltaic power supply capacity as the core basis, and employing ice storage capacity as a buffer redundancy. This is complemented by a targeted and precise air delivery system adapted to the large space of dairy cow sheds, accurately delivering cooling energy to the core activity areas of the dairy cows. Ultimately, this achieves low-carbon, energy-saving, efficient, and precise prevention and control of dairy cow heat stress.

[0006] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows: This invention provides a photovoltaic-ice storage cooling environment control system for dairy cow sheds. The environmental control system includes: a power supply end, a cooling and cold storage end, an air supply end, and a monitoring and control end; The monitoring and control terminal is bidirectionally connected to the power supply terminal, the cooling and cold storage terminal, and the air supply terminal, respectively, and serves as the central control hub of the system. The power supply input terminal of the cooling and cold storage terminal is electrically connected to the power supply terminal, and the power supply terminal generates electrical energy to drive the cooling and cold storage terminal. The cold air output terminal of the cooling and cold storage terminal is sealed to the air supply terminal through an air supply duct. The power supply end includes a photovoltaic unit 2 and a power grid unit 4 connected by a frequency converter 5, which together supply power to the cooling and cold storage end; the photovoltaic unit includes a photovoltaic panel 2 installed on the roof of the cowshed 1, the photovoltaic panel 2 is connected to an integrated inverter 3, which converts the DC power generated by the photovoltaic panel 2 into AC power; the integrated inverter 3 and the power grid unit 4 supply power to the cooling and cold storage end via the frequency converter 5; the power supply end has a built-in photovoltaic output acquisition unit for collecting photovoltaic output data. The refrigeration and cold storage end includes a compressor 6, a condenser 7, a throttle valve 8, an evaporator 9, a cooling tower 10, a cooling pump 11, an ice storage tank 12, a plate heat exchanger 13, a chilled water pump 14, a fan coil unit 15, an ethylene glycol circulation pump 17, and an electric three-way diverter valve 18. The compressor 6 of the refrigeration and cold storage end is electrically connected to the frequency converter 5. The compressor 6, condenser 7, throttle valve 8, and evaporator 9 are connected in sequence through pipes to form a dual-condition refrigeration unit 16, forming a refrigerant circulation loop. The condenser 7, cooling tower 10, and cooling pump 11 are connected in sequence through pipes to form a closed loop, forming a cooling water circulation loop. The evaporator 9 is connected to the electric three-way diverter valve 18, and the two outlets of the electric three-way diverter valve 18 are connected in parallel. The cooling supply branch and ice storage branch are configured as follows: the cooling supply branch is connected to the ethylene glycol side inlet of the plate heat exchanger 13, and the ice storage branch is connected to the heat exchange coil inlet of the ice storage tank 12; the outlet of the ethylene glycol side of the plate heat exchanger 13 and the outlet of the heat exchange coil of the ice storage tank 12 merge and then flow back to the evaporator 9 via the ethylene glycol circulation pump 17, forming an ethylene glycol refrigerant circulation loop; the chilled water side of the plate heat exchanger 13, the chilled water pump 14, and the fan coil unit 15 are connected in sequence through pipes to form a closed loop, constituting an air conditioning chilled water circulation loop; the controlled end of the electric three-way diverter valve 18 is bidirectionally connected to the monitoring and control end for dynamically distributing the flow direction and flow rate of the low-temperature ethylene glycol solution; the refrigeration and cold storage end is equipped with an ice storage sensor acquisition unit for collecting ice storage data; The air supply end includes a perforated air duct 20 located above the cow bed 21; the perforated air duct 20 is connected to the cold air outlet of the fan coil unit 15 of the refrigeration and cold storage end, and delivers low-temperature air to the cow bed 21 through the perforated air duct 20. The monitoring and control terminal includes a signal acquisition unit and a control output unit. The signal acquisition unit is connected to temperature sensors, relative humidity sensors, solar radiation sensors, ice storage sensor acquisition units and photovoltaic power acquisition units that are distributed inside and outside the cow shed. It is used to collect environmental parameters inside and outside the dairy cow shed in real time, and calculate and classify the temperature and humidity index (THI) based on the collected temperature and relative humidity data. ; Where T is temperature in Celsius; RH is relative humidity percentage; The control output unit includes an EMS energy management control component and an industrial communication component, which are bidirectionally connected to the controlled ends of the power supply end and the refrigeration and cold storage end, respectively. It generates and issues control commands based on THI level, photovoltaic output data, and ice storage data, thereby controlling the power supply end to switch power supply modes and the refrigeration and cold storage end to switch operating modes, adapting to different dairy shed cooling scenarios.

[0007] Preferred, The perforated duct 20 is provided with an array of holes with gradually varying diameters and spacings along its length to achieve approximately constant airflow. The duct wall of the perforated duct 20 is provided with an array of holes with gradually varying diameters and spacings along its length, and the opening direction is at a 15° angle to the vertical direction towards the cow bed 21. Each perforated duct 20 has a double-layer insulation structure, with an insulation interlayer between the inner and outer layers to reduce the cold bridge effect. The perforated duct 20 is equipped with a replaceable perforated plate or an adjustable air outlet sleeve to adapt to the heat and humidity load of cattle sheds in different areas. The perforated duct 20 has a drainage hole at its lowest point, which is connected to the ground drainage ditch through a flexible hose to prevent condensation from dripping onto the cow's body.

[0008] This invention also provides a photovoltaic-ice storage cooling environment control method for dairy barns, based on the aforementioned control system. The power supply modes at the power supply end include photovoltaic power generation, photovoltaic power generation + grid power supply, and grid power supply. The refrigeration and cold storage terminal operation modes include refrigeration + ice storage, refrigeration, refrigeration + ice melting, ice storage, and ice melting; The THI classification levels are: low, medium, and high, corresponding to no, mild, and moderate to severe heat stress states in dairy cows, respectively. When the THI level is low, the monitoring and control terminal adjusts the power supply to "photovoltaic power generation" mode, supplying power solely to the photovoltaic units. When the photovoltaic power is sufficient and a warning of a THI level increase is received, the cooling and cold storage terminal is adjusted to ice storage mode. If the THI level is predicted to rise to mild heat stress, ice storage is maintained until the ice storage volume reaches the upper limit of the conventional ice storage target. If the THI level is predicted to rise to moderate to severe heat stress, ice storage is maintained until the ice storage volume reaches the lower limit of the preventive ice storage target. When the photovoltaic power is sufficient, a warning of a THI level increase is received, and the ice storage volume has not reached the lower limit of the conventional ice storage target, the cooling and cold storage terminal is adjusted to ice storage mode until the ice storage volume reaches the lower limit of the conventional ice storage target, then the cooling and cold storage terminal is adjusted to standby mode. When the photovoltaic power is insufficient, the cooling and cold storage terminal is adjusted to standby mode. When the THI (Total Hidden Heat) level is medium, the monitoring and control terminal first determines whether the photovoltaic power is sufficient. If the photovoltaic power is sufficient and a THI level escalation warning is received, the power supply terminal is adjusted to "Photovoltaic Power Generation" mode, with the photovoltaic units supplying power independently. Simultaneously, it is determined whether the ice storage capacity has reached the lower limit of the preventive ice storage target. If the ice storage capacity has not reached the target, the cooling and cold storage terminal is adjusted to "Cooling" or "Cooling + Ice Storage" mode to prioritize meeting the real-time cooling needs of the cattle shed. Excess cooling capacity is used for ice storage until the ice storage capacity reaches the preventive ice storage target. Then, the cooling and cold storage terminal is adjusted to "Cooling" mode. If the photovoltaic power is sufficient and there is no THI level escalation warning, the power supply terminal is adjusted to "Photovoltaic Power Generation" mode, with the photovoltaic units supplying power independently. Simultaneously, it is determined whether the ice storage capacity has reached the target. If the ice storage capacity falls below the lower limit of the conventional ice storage target, the cooling and cold storage end is adjusted to "cooling" or "cooling + ice storage" mode to prioritize meeting the real-time cooling needs of the cattle shed. Excess cooling capacity is used for ice storage until the ice storage capacity reaches the upper limit of the conventional ice storage target. Then, the cooling and cold storage end is adjusted to "cooling" mode. If the photovoltaic power is insufficient, it is determined whether the ice storage capacity is greater than the minimum safe ice storage capacity. If the ice storage capacity is greater than the minimum safe ice storage capacity, the cooling and cold storage end is adjusted to "cooling + ice melting" or "ice melting" mode to prioritize using ice storage to supplement the cooling capacity gap. If the ice storage capacity is less than or equal to the minimum safe ice storage capacity, the power supply end is adjusted to "photovoltaic power generation + grid power supply" mode, and the cooling and cold storage end is adjusted to "cooling" mode to ensure the basic cooling needs of the cattle shed. When THI is at an advanced level, the monitoring and control terminal first determines whether the photovoltaic power is sufficient. If the photovoltaic power is sufficient, the power supply terminal is adjusted to the "photovoltaic power generation" mode, and the photovoltaic units supply power independently. Simultaneously, the ice storage status is determined: the cooling and cold storage terminal is adjusted to the cooling mode. If there is a surplus in the real-time cooling load, ice storage is added simultaneously until the ice storage reaches the preventive ice storage target. If there is still a cooling gap under extreme high load, the "ice melting" mode is activated to provide supplementary cooling. If the photovoltaic power is insufficient, the power supply terminal is adjusted to the "photovoltaic power generation + grid power supply" mode, with the photovoltaic units supplying power first, and the power gap being filled by the grid. Simultaneously, the ice storage status is determined: if the ice storage is greater than the minimum safe ice storage, the cooling and cold storage terminal is adjusted to the "cooling + ice melting" mode or the "ice melting" mode to maximize the use of cold storage to supplement the cooling gap and reduce grid power consumption. If the ice storage is less than or equal to the minimum safe ice storage, the cooling and cold storage terminal is adjusted to the cooling mode to ensure the cooling needs of the cattle shed under severe heat stress.

[0009] Preferred, The operation mode of the refrigeration and cold storage end is controlled by the monitoring and control terminal, as follows: When the dual-mode main unit 16 is in operation, the power supply drives the compressor 6 to compress the refrigerant to a high-temperature, high-pressure gaseous state and then it enters the condenser 7. After being cooled by the cooling water circulated by the cooling pump 11 and the cooling tower 10, the refrigerant condenses into a high-pressure liquid state. After being throttled by the expansion valve 8, the pressure is reduced to a low-temperature, low-pressure gas-liquid mixture, which enters the evaporator 9 to absorb heat and cool the ethylene glycol solution in the evaporator. The monitoring and control terminal dynamically distributes the flow direction of the low-temperature ethylene glycol solution through the electric three-way diverter valve 18, and controls the refrigeration and cold storage terminal to switch between the following operating modes: When the system is in "ice storage" mode, the monitoring and control terminal controls the cooling pump 11 and cooling tower 10 to run synchronously. The electric three-way diversion valve 18 shuts off the cooling supply branch and opens the ice storage branch. The ethylene glycol circulation pump 17 drives all the low-temperature ethylene glycol to flow into the ice storage tank 12. Through heat exchange, the water outside the coil freezes, and all the photovoltaic power is converted into cold energy and stored in the form of ice, thus completing ice making and cold storage. When the system is in "cooling + ice storage" mode, the monitoring and control terminal controls the dual-mode host 16, cooling pump 11, cooling tower 10, ethylene glycol circulation pump 17, chilled water pump 14 and fan coil unit 15 to operate synchronously. The electric three-way diversion valve 18 simultaneously opens the cooling supply branch and the ice storage branch. The low-temperature ethylene glycol prepared by the evaporator 9 prioritizes the flow of the cooling supply branch, enters the plate heat exchanger 13 to prepare chilled water, and supplies cooling to the cattle shed through the fan coil unit 15. The low-temperature ethylene glycol that exceeds the real-time cooling demand enters the ice storage branch and enters the metal coil of the ice storage tank 12, causing the water outside the coil to freeze, completing the ice making and cold storage, and converting the remaining photovoltaic power into the latent heat of phase change of ice. When the system is in "cooling" mode, the electric three-way diversion valve 18 closes the ice storage branch and opens the cooling supply branch. All low-temperature ethylene glycol cooling branches prepare low-temperature chilled water through the plate heat exchanger 13, and then supply cooling to the cattle shed through the fan coil unit 15. When the system is in "cooling" mode, the monitoring and control terminal controls the dual-mode host 16, cooling pump 11, cooling tower 10, ethylene glycol circulation pump 17, chilled water pump 14 and fan coil unit 15 to operate synchronously. The electric three-way diversion valve 18 shuts off the ice storage branch and opens the cooling branch. All low-temperature ethylene glycol cooling branches prepare low-temperature chilled water through plate heat exchanger 13, and then supply cooling to the cattle shed through fan coil unit 15. When the system is in "cooling + ice melting" mode, the monitoring and control terminal controls the dual-mode main unit 16, cooling pump 11, cooling tower 10, ethylene glycol circulation pump 17, chilled water pump 14 and fan coil unit 15 to operate synchronously. The electric three-way diversion valve 18 opens the cooling supply branch and the ice storage branch. The low-temperature ethylene glycol directly supplied by the dual-mode main unit 16 enters the cooling supply branch and the ice storage branch simultaneously through the electric three-way diversion valve 18. The low-temperature ethylene glycol after melting and cooling in the ice storage tank 12 merges with the ethylene glycol after heat exchange in the cooling supply branch and flows back to the evaporator 9 through the ethylene glycol circulation pump 17, jointly providing cooling for the cattle shed.

[0010] When the system is in "ice melting" mode, the dual-mode main unit 16 stops running, and only the ethylene glycol circulation pump 17, chilled water pump 14, and fan coil unit 15 are started. The ethylene glycol circulation pump 17 drives the ethylene glycol solution into the ice storage tank 12, where it is cooled into a low-temperature ethylene glycol solution by absorbing the cold energy from the melting ice. The low-temperature ethylene glycol is then sent to the plate heat exchanger 13 via the ethylene glycol circulation pump 17 to prepare low-temperature chilled water, which is then supplied to the cattle shed for cooling via the fan coil unit 15. The ethylene glycol that has been heated by heat exchange flows back to the ethylene glycol circulation pump 17, forming an independent closed loop for ice melting and cooling.

[0011] Preferred, The THI classification is as follows: THI<72 is low, 72≤THI<79 is medium, and THI≥79 is high, corresponding to no, mild, and moderate to severe heat stress states in dairy cows, respectively.

[0012] Preferred, Sufficient photovoltaic power is defined as real-time output power of the photovoltaic unit ≥ 60% of the rated operating power of the cooling and cold storage end; insufficient photovoltaic power is defined as real-time output power of the photovoltaic unit < 60% of the rated operating power of the cooling and cold storage end. With the rated maximum ice storage capacity of the ice storage pool as 100%, the entire range of ice storage capacity is divided into three control threshold ranges, as follows: Level 1 lower limit safety control range: 0% ≤ ice storage capacity < 20%, of which 15% is the minimum safe ice storage critical value, which is the lower limit protection threshold for ice melting and cooling, used for safety protection control when the ice storage capacity is too low; Level 2 daily control range: 20% ≤ ice storage capacity < 90%, of which 60%~80% is the target ice storage range for normal operating conditions, used for cold storage capacity regulation under normal operating conditions; Level 3 extreme operating condition preventive control range: 90% ≤ ice storage capacity ≤ 100%, used for early cold storage control in extreme high temperature warning and continuous high radiation conditions.

[0013] Preferred, The target ice storage capacity can be adjusted based on the herd's lactation cycle, stocking density, and milk production rhythm.

[0014] Preferred, Based on weather forecasts of temperature and humidity data and photovoltaic power generation prediction data, the monitoring and control system calculates the THI (Heat Intake) trend in dairy barns within a set time period. When a predicted increase in THI is expected, the target ice storage capacity is adjusted upwards within the set timeframe: if the predicted THI increases to mild heat stress, the target ice storage capacity is adjusted to 80% of the upper limit of the regular ice storage target; if the predicted THI increases to moderate to severe heat stress / extreme high temperature conditions, the target ice storage capacity is adjusted to 90% of the lower limit of the preventative ice storage target; if the predicted THI decreases to below the low-level heat stress threshold in the future, the target ice storage capacity is adjusted downwards to 60% of the lower limit of the regular ice storage target. When it is predicted that the THI (Heat Intake) of the dairy barn will remain in a stable state of heat stress for a set period of time, and the predicted output of photovoltaic power generation during the corresponding period is continuously lower than 30% of the rated power of the cooling and cold storage end, the monitoring and control terminal will lower the target ice storage capacity to 60% of the lower limit of the conventional ice storage target to reduce system energy consumption; after the target ice storage capacity is lowered, the real-time ice storage capacity shall not be lower than the minimum safe ice storage capacity.

[0015] Preferred, The control method is based on the photovoltaic power generation period and the real-time heat load of the cattle shed, and the monitoring and control terminal performs differentiated operation and control according to the season. Specifically: Summer operating conditions: During the daytime when the solar radiation intensity is at a medium / high level, the system will prioritize switching to the "photovoltaic power generation" mode, driving the cooling and cold storage end to simultaneously execute the "cooling + ice storage" mode—prioritizing the real-time cooling demand of the cattle shed. Any remaining cooling capacity of the cooling and cold storage end beyond the real-time cooling demand will be used for ice production and cold storage in the ice storage tank. During the nighttime when there is no effective solar radiation, the cold storage capacity of the ice storage tank will be used to execute the "ice melting + cooling" mode. Only when the ice storage capacity is less than or equal to the minimum safe ice storage capacity and the temperature and humidity index (THI) of the cattle shed exceeds the medium heat stress threshold will the "grid power supply" be supplemented to drive the cooling. Transitional season operating conditions: When the real-time THI of the cattle shed reaches the medium level or above, ice storage is only added during the day when the photovoltaic power is sufficient and there is a surplus in cooling demand, and the dual-condition main unit is stopped at night. Winter operating conditions: Stop the ice-making and refrigeration operation of the cold storage end, and only regulate the ambient temperature and humidity through the cattle shed ventilation system. When the relative humidity in the shed is >80%, the dehumidification mode can be turned on for a short time.

[0016] Preferred, The control thresholds for the cowshed environment in the control method are as follows: the environmental temperature control threshold for the cowshed activity area can be set from 8℃ to 26℃ according to the breed of dairy cow and the lactation cycle, of which the upper limit for heat stress prevention and control is 26℃ and the lower limit for low temperature protection is 8℃; the target for relative humidity control in the cowshed environment is 50% to 75%.

[0017] The beneficial effects of this invention are: (1) Resource and environmental benefits: Improve resource utilization and achieve low-carbon aquaculture. The system makes full use of the idle rooftop resources of dairy sheds to install photovoltaic arrays without requiring additional land use, thus significantly improving land resource utilization. The system uses clean photovoltaic power as the main energy source, which can significantly reduce fossil energy consumption and carbon emissions in the breeding process, in line with the policy orientation of green and low-carbon development in the large-scale breeding industry. (2) System reliability benefits: Constructing multi-dimensional buffer redundancy ensures the continuity and stability of cooling supply. The ice storage system enables the storage of cold energy from photovoltaic power, solving the inherent defects of randomness, volatility, and intermittency in photovoltaic power generation. It does not rely on grid absorption, avoiding the impact of photovoltaic grid connection on the grid. At the same time, it replaces traditional chemical energy storage batteries, avoiding the problems of high cost, short life and high pollution of batteries. By setting a minimum safe ice storage threshold, emergency cold energy redundancy is reserved for scenarios such as extreme high temperature, sudden photovoltaic interruption, and grid failure, ensuring the continuity of heat stress prevention and control for dairy cows. (3) Core energy-saving benefits: Maximizes self-consumption of photovoltaic power generation and significantly reduces grid power consumption and operating costs. Using ice storage technology can effectively reduce the operating costs of air conditioning, optimize the matching of power supply and demand, use photovoltaic power generation systems to drive the system, utilize solar energy, improve the utilization rate of renewable energy, reduce electricity costs, and at the same time, ice storage systems can store the electricity generated by photovoltaic power generation, replacing costly and environmentally unfriendly batteries, and significantly reducing unnecessary grid power consumption. (4) Stability benefits: Pre-emptive ice making by predictive scheduling can alleviate peak loads during high-temperature periods, avoid cooling fluctuations, and improve the stability of the indoor environment; (5) Intelligent control benefits: It realizes fully closed-loop unmanned operation and reduces operation and maintenance costs. The monitoring and control terminal enables fully closed-loop intelligent control, including environmental parameter acquisition, THI calculation, strategy matching, equipment regulation, and effect verification. It can dynamically adjust the operating strategy according to the season, weather, photovoltaic output, and dairy cow heat stress status without manual intervention, which greatly reduces the difficulty of system operation and maintenance and labor costs. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 A schematic diagram of the operation of a photovoltaic-ice storage cooling system for a dairy cow shed; Figure 2 A floor plan of the dairy barn after the installation of the photovoltaic-ice storage cooling system; Figure 3 A schematic diagram of the cowshed facade after the installation of the photovoltaic-ice storage cooling system; Figure 4 A partial schematic diagram of the cow shed after the installation of the photovoltaic-ice storage cooling system; Figure 5 Flowchart of the operation and control strategy for the photovoltaic-ice storage cooling system in a dairy shed.

[0019] Explanation of reference numerals in the attached figures: 1. Cow shed; 2. Photovoltaic panel; 3. Reverse control unit; 4. Power grid unit; 5. Frequency converter; 6. Compressor; 7. Condenser; 8. Throttling valve; 9. Evaporator; 10. Cooling tower; 11. Cooling pump; 12. Ice storage tank; 13. Plate heat exchanger; 14. Chilled water pump; 15. Fan coil unit; 16. Dual-mode main unit; 17. Ethylene glycol circulation pump; 18. Electric three-way diverter valve; 19. Monitoring and control terminal; 20. Perforated duct; 21. Cow bedding; 22. Refrigeration unit. Detailed Implementation

[0020] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the following embodiments are given for illustrative purposes only and are not intended to limit the scope of the present invention. Those skilled in the art can make various modifications and substitutions to the present invention without departing from its spirit and essence.

[0021] This invention provides a photovoltaic-ice storage cooling environment control system for dairy cow sheds and its operation method. Photovoltaic power generation is achieved by laying photovoltaic panels on the roof of the dairy cow shed. The photovoltaic modules drive the compressor to produce cold air, which is then used to store the cold energy by utilizing the latent heat of phase change of ice. The cold energy is then released and precisely delivered to the cows' beds through perforated ducts, providing low-temperature air to the cow shed. This results in low-carbon, energy-saving, efficient, and precise cooling of the dairy cow shed.

[0022] 1. Overall Structure of Photovoltaic-Ice Storage Cooling Environment Control System for Dairy Cow Sheds like Figure 1 As shown, this invention provides a photovoltaic-ice storage cooling environment control system and its control method for a dairy cow shed. The system includes a power supply end, a cooling and storage end, an air supply end, and a monitoring and control end. The monitoring and control end serves as the central control hub of the system. Its communication ports are bidirectionally connected to the power supply end, cooling and storage end, and air supply end, respectively. Data interaction with these ends is achieved through industrial Ethernet and RS485 industrial bus. This allows for the collection of system operation data, core calculations and strategy generation, and the issuance of linkage control commands to each end, forming a closed-loop control. The power input end of the cooling and storage end is electrically connected to the power supply end, and the cold air output end of the cooling and storage end is connected to the heat exchange components of the air supply end through an air supply duct, providing cooling capacity to the air supply end. The signal acquisition end of the monitoring and control end is communicatively connected to sensor units inside and outside the dairy cow shed.

[0023] The power supply side includes a photovoltaic unit and a grid unit 4 connected via a frequency converter 5, which together supply power to the cooling and cold storage end. The photovoltaic unit includes multiple photovoltaic panels 2 fixedly installed on the roof of the cowshed 1 via brackets to convert solar energy into DC power. The power output of the photovoltaic panels 2 is electrically connected to the DC input of the inverter 3, which converts the DC power generated by the photovoltaic panels 2 into AC power. The AC side of the inverter 3 is simultaneously connected to the grid unit 4 and the input of the frequency converter 5 to supply power to the cooling and cold storage end, realizing a power supply strategy of photovoltaic priority and grid power as a backup. It prioritizes the consumption of photovoltaic self-generated energy and only supplements grid power supply when photovoltaic output is insufficient. The output of the frequency converter 5 is electrically connected to the compressor 6 of the cooling and cold storage end to adjust the operating frequency and output power of the compressor 6 to match the real-time load demand of the system. The cowshed 1 is an open cowshed, including a roof, supporting structure and open side walls, which is suitable for the needs of large-scale dairy farming.

[0024] The refrigeration and cold storage end includes a dual-condition refrigeration unit 16, a cooling tower 10, a cooling pump 11, an ice storage tank 12, a plate heat exchanger 13, a chilled water pump 14, a fan coil unit 15, an ethylene glycol circulation pump 17, and an electric three-way diverter valve 18. The dual-condition refrigeration unit 16 has a built-in compressor 6, a condenser 7, a throttling valve 8, and an evaporator 9. The ice storage tank 12 is located on both sides of the gable walls of the cowshed 1. The dual-condition refrigeration unit 16, the cooling pump 11, the plate heat exchanger 13, the chilled water pump 14, the ethylene glycol circulation pump 17, and the electric three-way diverter valve 18 are integrated and installed in the refrigeration unit casing 22 next to the ice storage tank 12. The cooling tower 10 is located in a well-ventilated open area outside the refrigeration unit casing 22 to dissipate heat from the dual-condition refrigeration unit 16.

[0025] The refrigeration and cold storage end is equipped with four independent closed-loop circuits that are coupled together by plate heat exchangers, as detailed below: 1) Cooling water circulation loop: The cooling water outlet of the condenser 7 is connected to the water inlet of the cooling tower 10, the water outlet of the cooling tower 10 is connected to the water inlet of the cooling pump 11, and the water outlet of the cooling pump 11 is connected to the cooling water inlet of the condenser 7, so as to provide circulating cooling water for refrigerant condensation. 2) Refrigerant circulation loop: Compressor 6, condenser 7, expansion valve 8, and evaporator 9 are connected in sequence through pipes to form ice storage dual-condition main unit 16; Low-temperature and low-pressure gaseous refrigerant is compressed into high-temperature and high-pressure gaseous state by compressor 6 and sent into condenser 7. After being cooled by cooling water provided by cooling tower 10 and cooling pump 11, it is condensed into high-pressure liquid refrigerant. Then, it is throttled and depressurized by expansion valve 8 into a low-temperature and low-pressure gas-liquid mixture. After entering evaporator 9 to absorb heat and refrigerate, it returns to compressor 6 to complete the cycle; 3) Ethylene glycol refrigerant circuit: The ethylene glycol side outlet of the evaporator 9 is connected to the inlet of the electric three-way diverter valve 18. The two outlets of the electric three-way diverter valve 18 correspond to the parallel cooling branch and the ice storage branch, respectively: the cooling branch is connected to the ethylene glycol side inlet of the plate heat exchanger 13, and the ice storage branch is connected to the inlet of the heat exchange coil inside the ice storage tank 12; after the outlets of the plate heat exchanger 13 and the heat exchange coil of the ice storage tank 12 merge, the water flows back to the ethylene glycol side inlet of the evaporator 9 via the ethylene glycol circulation pump 17. A closed loop is formed under the main unit's operating conditions; under the ice-melting condition, the dual-condition refrigeration main unit 16 stops, and the ethylene glycol refrigerant circuit independently forms a closed loop of cold extraction from the ice storage tank 12 → plate heat exchanger 13 → ethylene glycol circulation pump 17 → ice storage tank 12; the refrigerant in the evaporator 9 absorbs heat and cools down the ethylene glycol solution to a low temperature of -5℃ to -2℃; the low-temperature ethylene glycol is dynamically distributed to the cooling supply branch and the ice storage branch through the electric three-way diversion valve 18, and the ethylene glycol that has been heated by heat exchange is pressurized and sent back to the evaporator 9 through the ethylene glycol circulation pump 17 to complete the cycle.

[0026] 4) Air Conditioning Chilled Water Circulation Loop: The chilled water outlet of plate heat exchanger 13 is connected to the inlet of chilled water pump 14, the outlet of chilled water pump 14 is connected to the inlet of fan coil unit 15, and the outlet of fan coil unit 15 is connected to the chilled water inlet of plate heat exchanger 13, forming a closed loop. Low-temperature ethylene glycol exchanges heat with the air conditioning chilled water in plate heat exchanger 13, cooling the chilled water to 7℃~10℃; the low-temperature chilled water is sent to fan coil unit 15 via chilled water pump 14, exchanges heat with the air in cowshed 1 for cooling, and then the heated chilled water returns to plate heat exchanger 13, completing the circulation.

[0027] like Figure 2 , 3 As shown in Figure 4, the air supply end includes a perforated duct 20, which is suspended above the cow bed 21 at the middle position. The air inlet of the perforated duct 20 is sealed to the air outlet of the fan coil unit 15, and is used to deliver low-temperature cold air into the cow shed 1. The wall of the perforated duct 20 is provided with an array of holes with gradually changing diameter and spacing along its length. The opening direction is at a 15° angle to the vertical direction towards the cow bed 21, so as to achieve an approximately constant air velocity along the length of the perforated duct, and the jet radiation range completely covers the area of ​​the cow bed 21. Each section of the perforated duct 20 is equipped with a replaceable perforated plate or an adjustable perforated sleeve, which can flexibly adjust the air outlet parameters according to the heat and humidity load of different areas of the cow shed to achieve targeted and precise cooling.

[0028] The monitoring and control system includes temperature and relative humidity sensors distributed throughout the barn. It calculates and classifies the heat stress index (THI) of the dairy barn based on temperature and relative humidity.

[0029] The photovoltaic-ice storage cooling environment control system and its control method in the dairy barn are as follows: 1. Sensing and THI computing Data fusion: Temperature and humidity sensors are deployed at 200~300 m² / point, with an installation height of 1.5~2.0 m, and the number of points is increased at both ends of the bed; median filtering, outlier removal (e.g., 3σ criterion) and redundancy consistency verification are performed on the raw temperature and humidity data.

[0030] THI is calculated based on temperature and relative humidity, using the following formula: ; Where T represents temperature in Celsius; RH represents relative humidity percentage. It is divided into three levels: low, medium, and high, corresponding to no, mild, and moderate-to-severe heat stress states in dairy cows, respectively.

[0031] The THI grading threshold is adjusted according to the breed / lactation stage.

[0032] 2. Multi-mode control strategy Power supply modes: photovoltaic power generation, photovoltaic power generation + grid power supply, grid power supply.

[0033] Refrigeration and cold storage end operation modes: refrigeration + ice storage, refrigeration, refrigeration + ice melting, ice storage, ice melting.

[0034] like Figure 5 The diagram shown is a flowchart of the operation and control strategy of the photovoltaic-ice storage cooling system in a dairy shed.

[0035] We define THI < 72 as low level, 72 ≤ THI < 79 as medium level, and THI ≥ 79 as high level.

[0036] When the THI level is low, the monitoring and control terminal adjusts the power supply to "photovoltaic power generation" mode, supplying power solely to the photovoltaic units. When photovoltaic power is sufficient and a THI level increase warning is received, the cooling and cold storage terminal is adjusted to ice storage mode. If the THI level is predicted to rise to mild heat stress, ice storage is maintained until the ice storage volume reaches the upper limit of the conventional ice storage target. If the THI level is predicted to rise to moderate to severe heat stress, ice storage is maintained until the ice storage volume reaches the lower limit of the preventive ice storage target. When photovoltaic power is sufficient, there is no THI level increase warning, and the ice storage volume has not reached the lower limit of the conventional ice storage target, the cooling and cold storage terminal is adjusted to ice storage mode until the ice storage volume reaches the lower limit of the conventional ice storage target, then the cooling and cold storage terminal is adjusted to standby mode. When photovoltaic power is insufficient, the cooling and cold storage terminal is adjusted to standby mode. When the THI (Total Hidden Heat) level is medium, the monitoring and control terminal first determines whether the photovoltaic power is sufficient. If the photovoltaic power is sufficient and a THI level escalation warning is received, the power supply terminal is adjusted to "Photovoltaic Power Generation" mode, with the photovoltaic units supplying power independently. Simultaneously, it is determined whether the ice storage capacity has reached the lower limit of the preventive ice storage target. If the ice storage capacity has not reached the target, the cooling and cold storage terminal is adjusted to "Cooling" or "Cooling + Ice Storage" mode to prioritize meeting the real-time cooling needs of the cattle shed. Excess cooling capacity is used for ice storage until the ice storage capacity reaches the preventive ice storage target. Then, the cooling and cold storage terminal is adjusted to "Cooling" mode. If the photovoltaic power is sufficient and there is no THI level escalation warning, the power supply terminal is adjusted to "Photovoltaic Power Generation" mode, with the photovoltaic units supplying power independently. Simultaneously, it is determined whether the ice storage capacity has reached the target. If the ice storage capacity falls below the lower limit of the conventional ice storage target, the cooling and cold storage end is adjusted to "cooling" or "cooling + ice storage" mode to prioritize meeting the real-time cooling needs of the cattle shed. Excess cooling capacity is used for ice storage until the ice storage capacity reaches the upper limit of the conventional ice storage target. Then, the cooling and cold storage end is adjusted to "cooling" mode. If the photovoltaic power is insufficient, it is determined whether the ice storage capacity is greater than the minimum safe ice storage capacity. If the ice storage capacity is greater than the minimum safe ice storage capacity, the cooling and cold storage end is adjusted to "cooling + ice melting" or "ice melting" mode to prioritize using ice storage to supplement the cooling capacity gap. If the ice storage capacity is less than or equal to the minimum safe ice storage capacity, the power supply end is adjusted to "photovoltaic power generation + grid power supply" mode, and the cooling and cold storage end is adjusted to "cooling" mode to ensure the basic cooling needs of the cattle shed. When THI is at an advanced level, the monitoring and control terminal first determines whether the photovoltaic power is sufficient. If the photovoltaic power is sufficient, the power supply terminal is adjusted to the "photovoltaic power generation" mode, and the photovoltaic units supply power independently. Simultaneously, the ice storage status is determined: the cooling and cold storage terminal is adjusted to the cooling mode. If there is a surplus in the real-time cooling load, ice storage is added simultaneously until the ice storage reaches the preventive ice storage target. If there is still a cooling gap under extreme high load, the "ice melting" mode is activated to provide supplementary cooling. If the photovoltaic power is insufficient, the power supply terminal is adjusted to the "photovoltaic power generation + grid power supply" mode, with the photovoltaic units supplying power first, and the power gap being filled by the grid. Simultaneously, the ice storage status is determined: if the ice storage is greater than the minimum safe ice storage, the cooling and cold storage terminal is adjusted to the "cooling + ice melting" mode or the "ice melting" mode to maximize the use of cold storage to supplement the cooling gap and reduce grid power consumption. If the ice storage is less than or equal to the minimum safe ice storage, the cooling and cold storage terminal is adjusted to the cooling mode to ensure the cooling needs of the cattle shed under severe heat stress.

[0037] 3. Specific workflow of refrigeration and cold storage end operation mode The monitoring and control system dynamically adjusts five operating modes of the refrigeration and cold storage end based on the real-time THI level of the dairy shed, the real-time output of the photovoltaic units, and the real-time ice storage capacity of the ice storage tank. These modes include "refrigeration + ice storage", "refrigeration", "refrigeration + ice melting", "ice storage", and "ice melting", as detailed below: 1) "Ice Storage" Mode Triggering condition: Photovoltaic power is sufficient, but ice storage capacity does not meet the standard.

[0038] Workflow: The monitoring and control terminal issues a command to start the dual-mode host 16 (switching to ice storage mode), and simultaneously operate the cooling pump 11, cooling tower 10, and ethylene glycol circulation pump 17. At the same time, the electric three-way diversion valve 18 is adjusted to completely shut off the cooling supply branch and open the ice storage branch. The -5℃~-2℃ low-temperature ethylene glycol solution prepared by the dual-mode host 16 enters the ice storage branch and flows into the metal coil in the ice storage tank 12. Through heat exchange, the water outside the coil freezes, and all photovoltaic power is converted into cold energy and stored in the form of ice, completing the ice-making and cold storage process. The fan coil unit 15 and chilled water pump 14 stop operating, and no cooling is supplied to the cowshed 1 throughout the process.

[0039] 2) "Refrigeration + Ice Storage" Mode Triggering conditions: When THI is at medium or high level, photovoltaic power is sufficient, and ice storage capacity has not reached the target lower limit for the corresponding conditions.

[0040] Workflow: The monitoring and control terminal controls the dual-mode host 16 to start, and the cooling pump 11, cooling tower 10, ethylene glycol circulation pump 17, chilled water pump 14 and fan coil unit 15 to run synchronously. The electric three-way diversion valve 18 is adjusted to simultaneously connect the cooling supply branch and the ice storage branch. The low-temperature ethylene glycol prepared by the evaporator 9 prioritizes the flow of the cooling supply branch and enters the plate heat exchanger 13 to exchange heat with the chilled water to prepare chilled water at 7℃~10℃. The chilled water is supplied to the cowshed 1 through the fan coil unit 15. The low-temperature ethylene glycol that exceeds the real-time cooling demand enters the metal coil of the ice storage tank 12 through the ice storage branch, causing the water outside the coil to freeze, completing the ice-making and cold storage, and converting the surplus photovoltaic power into the latent heat of phase change of ice for storage.

[0041] 3) "Cooling" mode Triggering conditions: When THI is at medium or high level, photovoltaic power is sufficient, and ice storage capacity has reached the standard; or under extreme high temperature conditions, priority should be given to ensuring the cooling needs of cattle shed 1.

[0042] Workflow: The monitoring and control terminal starts the dual-mode main unit 16, and the cooling pump 11, cooling tower 10, ethylene glycol circulation pump 17, chilled water pump 14 and fan coil unit 15 operate synchronously; the electric three-way diversion valve 18 is adjusted to close the ice storage branch and open the cooling branch. All the low-temperature ethylene glycol cooling branches prepared by the dual-mode main unit 16 are processed into low-temperature chilled water by the plate heat exchanger 13, and then sent to the fan coil unit 15 by the chilled water pump 14 to supply cooling to the cowshed 1.

[0043] 4) "Refrigeration + Ice Melting" Mode Triggering conditions: When THI is at medium or high level, photovoltaic power is insufficient, and ice storage capacity is greater than the minimum safe ice storage capacity, the cooling demand cannot be met by relying solely on the dual-condition main unit 16.

[0044] Workflow: The monitoring and control terminal controls the dual-mode refrigeration unit 16 to start, and the cooling pump 11, cooling tower 10, ethylene glycol circulation pump 17, chilled water pump 14 and fan coil unit 15 to run synchronously; the electric three-way diversion valve 18 is adjusted to simultaneously open the cooling supply branch and the ice storage branch. The low-temperature ethylene glycol directly supplied by the dual-mode refrigeration unit 16 enters the cooling supply branch and the ice storage branch simultaneously through the electric three-way diversion valve 18. The low-temperature ethylene glycol after melting ice in the ice storage tank 12 and exchanging heat with the ethylene glycol after heat exchange in the cooling supply branch are combined and returned to the evaporator 9 through the ethylene glycol circulation pump 17, jointly providing cooling for the cattle shed.

[0045] 5) "Ice Melting" Mode Triggering conditions: When THI is in medium or high level, photovoltaic power is insufficient, ice storage capacity is greater than the minimum safe ice storage capacity, and photovoltaic power is insufficient to support the cooling power requirements of the dual-condition host 16.

[0046] Workflow: The monitoring and control terminal completely stops the dual-mode refrigeration unit 16, only starting the ethylene glycol circulation pump 17, chilled water pump 14, and fan coil unit 15; the ethylene glycol circulation pump 17 drives the ethylene glycol solution into the metal coil inside the ice storage tank 12, where it is cooled into a low-temperature ethylene glycol solution by absorbing the cold energy from the melting ice; the low-temperature ethylene glycol flows out of the ice storage tank 12 and is sent to the plate heat exchanger 13 to exchange heat with the chilled water to prepare low-temperature chilled water, which is then supplied to the cowshed 1 for cooling via the fan coil unit 15; the ethylene glycol solution, after being heated by heat exchange, flows back to the ethylene glycol circulation pump 17, forming an independent ice melting and cooling closed loop, which does not require starting the main unit and can reduce mains power consumption.

[0047] 4. Predictive scheduling and target ice storage This system achieves coordinated ice storage scheduling based on heat stress prediction and photovoltaic output forecasting through a monitoring and control terminal. With the core principles of prioritizing heat stress prevention and control in dairy cows and maximizing photovoltaic self-consumption, it dynamically adjusts the target ice storage capacity, as detailed below: 4.1 Prediction Basis and Time Dimension The monitoring and control terminal connects to the meteorological numerical forecasting platform and the photovoltaic power output prediction model to obtain hourly weather forecast data (temperature, relative humidity, total solar irradiance, and cloudy / sunny status) for the farm area for the next 6 to 48 hours. Simultaneously, it completes two core predictions: hourly THI trend prediction for the dairy shed and hourly photovoltaic power output prediction. The photovoltaic power output prediction model uses an hourly power output prediction formula suitable for the farm's photovoltaic array, as shown in equation (2): ; in: Predicted output of photovoltaic array at any time, in kW; Rated installed capacity of photovoltaic array, kW; Real-time measured / predicted total solar irradiance, W / m 2 ; Standard test conditions: Irradiation intensity (1000 W / m²) 2 (publicly known fixed value); Photovoltaic module power temperature coefficient (constant, taken as -0.38 % / ℃); The surface temperature of the photovoltaic module at any given time, in °C; Let t be the ambient temperature, in °C; : Overall efficiency of photovoltaic system (including losses of integrated inverter and controller, valued at 0.85~0.92).

[0048] 4.2 Dynamic Regulation Rules for Target Ice Storage Capacity With the rated maximum ice storage capacity of the ice storage pool as 100%, the entire range of ice storage capacity is divided into three control threshold ranges, as follows: Level 1 lower limit safety control range: 0% ≤ ice storage capacity < 20%, of which 15% is the minimum safe ice storage critical value, which is the lower limit protection threshold for ice melting and cooling, used for safety protection control when the ice storage capacity is too low; Level 2 daily control range: 20% ≤ ice storage capacity < 90%, of which 60%~80% is the target ice storage range for normal operating conditions, used for cold storage capacity regulation under normal operating conditions; Level 3 extreme operating condition preventive control range: 90% ≤ ice storage capacity ≤ 100%, used for early cold storage control in extreme high temperature warning and continuous high radiation conditions.

[0049] Implement differentiated regulation based on forecast results: When it is predicted that the THI (Heat Stress) in the dairy barn will rise across different levels (from no heat stress to mild heat stress, or from mild heat stress to moderate to severe heat stress) within the next 6 to 48 hours, or when it is predicted that the ambient temperature will be ≥35℃, an extreme high temperature condition, the monitoring and control terminal will adjust the target ice storage capacity 2 to 6 hours in advance: when the THI is predicted to rise across different levels to mild heat stress, the target ice storage capacity will be adjusted to 80% of the upper limit of the regular ice storage target; when the THI is predicted to rise across different levels to moderate to severe heat stress / extreme high temperature condition, the target ice storage capacity will be adjusted to 90% of the lower limit of the preventive ice storage target. Priority will be given to using the remaining photovoltaic power at the current time to complete the ice making in advance. Only when the photovoltaic power is insufficient and the THI will drop below the low-level heat stress threshold will the target ice storage capacity be adjusted to 60% of the lower limit of the regular ice storage target to reduce unnecessary ice making energy consumption. When it is predicted that the THI of the dairy shed will remain stable in a state without heat stress (THI < 72) for the next 6 to 48 hours, and the predicted output of photovoltaic power generation during the corresponding period will be continuously lower than 30% of the rated power of the cooling and cold storage end (under cloudy / low temperature and low light conditions), the monitoring and control terminal will lower the target ice storage capacity to 60% of the lower limit of the conventional ice storage target, stop unnecessary ice storage operations, and reduce system energy consumption; after the target ice storage capacity is lowered, the real-time ice storage capacity shall not be lower than 15% of the minimum safe ice storage capacity to ensure emergency cooling capacity redundancy.

[0050] 4.3 Fine-tuning based on cattle herd characteristics The monitoring and control system can fine-tune the target ice storage capacity and environmental control thresholds based on the herd's lactation cycle, stocking density, and milk production rhythm. For cows in peak lactation and high-producing cows, whose sensitivity to heat stress is significantly higher than that of dry cows and low-producing cows, the target ice storage amount can be increased by 10% to 20% 2 to 6 hours before the peak lactation period, and the temperature control threshold in the barn can be lowered by 1 to 2°C to reserve cold energy in advance and avoid the decrease in milk production caused by heat stress during the lactation period. For high-density cattle sheds with a stocking density of ≥80 head / 1,000 square meters, the target ice storage capacity can be increased by 5% to 10% 2 to 4 hours in advance to match the higher heat load requirements.

[0051] 5. Seasonal Multi-mode Summer operating conditions: During the daytime when the solar radiation intensity is at the medium / high level, the system will prioritize switching to photovoltaic power generation mode, driving the cooling and cold storage end to simultaneously execute the "cooling + ice storage" mode—prioritizing the real-time cooling demand of the cattle shed. Any excess cooling capacity of the cooling and cold storage end beyond the real-time cooling demand will be used entirely for ice production and cold storage in the ice storage tank. During the nighttime when there is no effective solar radiation, the system will prioritize using the cold storage capacity of the ice storage tank to execute the "ice melting + cooling" mode. Only when the ice storage capacity is less than or equal to the minimum safe ice storage capacity and the temperature and humidity index (THI) of the cattle shed exceeds the medium heat stress threshold will the mains power be used to drive the cooling. Winter operation: Ice making and refrigeration at the cold storage end are stopped. The ambient temperature and humidity are regulated only through the ventilation system of the cattle shed. When the relative humidity in the shed is >80%, the dehumidification mode can be activated for a short time. The dehumidification mode is achieved through the coordinated operation of fan coil unit 15, air conditioning chilled water circulation loop, ethylene glycol refrigerant circulation loop, dual-condition refrigeration unit 16, electric three-way diverter valve 18 and monitoring and control terminal. The low-temperature heat exchange coil of fan coil unit 15 is used to condense and dehumidify the high humidity air in the cattle shed. Low-temperature chilled water is continuously supplied by the air conditioning chilled water circulation loop. The ethylene glycol refrigerant loop and the dual-condition refrigeration unit provide cooling support for dehumidification. The monitoring and control terminal regulates the cooling supply through electric three-way diverter valve 18 to achieve dehumidification operation in different scenarios.

[0052] Transitional season operating conditions: When the real-time THI of the cattle shed reaches medium or above, cooling is turned on as needed based on the daytime photovoltaic output. Ice storage is only added when the photovoltaic power is sufficient and the cooling demand is in surplus. At night, the environment is regulated by the ventilation system to reduce unnecessary mains power cooling and ice storage operations.

[0053] 6. Emergency Response and Troubleshooting The monitoring and control terminal is equipped with a multi-condition emergency and fault handling mechanism. When any of the following trigger conditions occur, it will automatically enter the emergency operation mode: (1) the real-time THI of the dairy cow house is ≥88 (severe heat stress safety threshold) or the ambient dry bulb temperature is ≥35℃, which is an extreme high temperature condition; (2) the core sensing equipment (temperature and humidity, solar radiation, ice storage sensor) malfunctions or data is abnormal; (3) the photovoltaic system output is abnormally interrupted or the power grid power supply is faulty / limited.

[0054] In emergency mode, heat stress prevention and control in dairy cows is the highest priority, and the following control strategies are implemented: Temporarily lift the restrictions on grid connection to the mains, prioritize the full-load operation of the refrigeration system, and implement maximum cooling capacity to reduce the temperature until the THI in the building drops to a safe range; Enable sensor redundancy backup and safety default values: When a single sensor fails, automatically switch to redundant sensor data in the same area; when the sensor data for the entire area is abnormal, enable historical safety default values ​​for the same season and time period to ensure basic system operation. When the photovoltaic system is operating normally, the photovoltaic power generation mode is still prioritized. Only when the photovoltaic output cannot meet the minimum cooling load will the grid power supply be supplemented to minimize grid power consumption.

[0055] When the indoor THI and temperature drop below the safe threshold and stably meet the hysteresis range and minimum residence time, the system automatically exits the emergency mode and resumes the normal mains power limiting strategy and normal operation logic.

[0056] 7. Terminal air supply and equipment protection structure The perforated duct 20 at the air supply end has a double-layer insulation structure. A closed-cell insulation interlayer is set between the inner and outer layers of the perforated duct to block the transfer of cold bridges and reduce the loss of cold energy. A continuous condensation collection channel is set at the bottom of the perforated duct along its length. Drainage holes are evenly opened at the bottom of the collection channel. The drainage holes are connected to the drainage ditch on the ground of the cowshed through a food-grade drainage hose. The condensate on the inner wall of the perforated duct can be concentrated and drained to the outside of the cowshed, which completely avoids the condensation dripping onto the cows or the bedding area 21, reducing the risk of limb and hoof diseases and mastitis in dairy cows and meeting the environmental hygiene requirements of dairy farming.

[0057] The installation areas of core equipment such as ice storage tank 12, dual-mode main unit 16, and chilled water pump 14 are equipped with washable waterproof curtains and ground drainage ditches to prevent water accumulation. The enclosure protection level of all electrical equipment is no less than IP54, which is suitable for dairy farms with high humidity, high dust, and the need for regular cleaning, ensuring long-term stable operation of the equipment.

[0058] 8. Adjustable range of core parameters The monitoring and control terminal has a built-in fully adjustable configuration module, which can flexibly adjust control parameters according to dairy cow breed, lactation cycle, farm climate characteristics, and power grid policies. The adjustable range of core parameters is as follows: Temperature control threshold for cowshed environment: comfortable temperature range of 5~26℃, which can be flexibly adjusted according to the breed of dairy cow and lactation cycle; The target for relative humidity control inside the building is 50%~75%. When the relative humidity inside the building is >85%, priority should be given to increasing the ventilation volume at the air supply end for dehumidification. Solar radiation intensity classification thresholds: <300 W / m² is low radiation level, 300~600 W / m² is medium radiation level, and ≥600 W / m² is high radiation level. On-site calibration can be completed according to the altitude and climate characteristics of the site. 9. Core control algorithm for monitoring and control terminal 9.1 Mode switching anti-shake mechanism The monitoring and control system is equipped with mode switching hysteresis debounce and minimum dwell time control to avoid frequent system mode switching caused by fluctuations in indoor temperature and humidity and photovoltaic output, ensuring a stable dairy barn environment and extending equipment lifespan. Adjustable hysteresis range: temperature hysteresis 1~2℃, THI hysteresis 2~3 units; The minimum dwell time after a single mode switch is adjustable from 10 to 15 minutes.

[0059] 9.2 Accurate Algorithm for Estimating Ice Storage Capacity The monitoring and control system employs a combined estimation method of liquid level sensing and transient thermal response to accurately calculate the real-time ice filling rate of the ice storage tank: Solid-liquid mixed liquid level data of the ice storage tank is acquired through ultrasonic / differential pressure liquid level sensors to perform a preliminary estimation of the ice filling rate; the actual cooling capacity of the ice storage tank is calculated by using the transient heat transfer response to system load changes; Kalman filtering is performed on the two sets of data to eliminate measurement errors from single-sensor methods, providing accurate data support for dynamic control of ice storage capacity and switching between ice melting and ice making modes, and precisely matching the cooling capacity requirements for heat stress prevention and control in dairy cows.

[0060] 9.3 Photovoltaic-Cooling Coordinated Droop Control Strategy The monitoring and control terminal controls the photovoltaic inverter integrated unit 3 and the compressor 6, and adopts a droop control strategy that adaptively adjusts according to the real-time output of the photovoltaic system: under the priority of photovoltaic power generation, the operating frequency and evaporation temperature of the compressor 6 are dynamically limited according to the real-time available output of the photovoltaic system, so that the load of the refrigeration system matches the available output of the photovoltaic system in real time, maximizes the absorption of photovoltaic power on the roof of the dairy barn, minimizes the probability of grid connection, and aligns with the core objective of maximizing the self-generation and self-consumption of photovoltaic power in the system.

[0061] Other facilities in the cattle shed, such as manure removal, feeding, and drinking water, are installed in accordance with those in a regular cattle shed.

[0062] This invention is an energy-saving, efficient, and precise cattle shed cooling system and control method, which is suitable for widespread application.

[0063] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0064] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A photovoltaic-ice storage cooling environment control system for dairy barns, characterized in that, The environmental control system includes: a power supply end, a cooling and cold storage end, an air supply end, and a monitoring and control end; The monitoring and control terminal is bidirectionally connected to the power supply terminal, the cooling and cold storage terminal, and the air supply terminal, respectively, and serves as the central control hub of the system. The power supply input terminal of the cooling and cold storage terminal is electrically connected to the power supply terminal, and the power supply terminal generates electrical energy to drive the cooling and cold storage terminal. The cold air output terminal of the cooling and cold storage terminal is sealed to the air supply terminal through an air supply duct. The power supply end includes a photovoltaic unit and a power grid unit (4) connected by a frequency converter (5), which together supply power to the cooling and cold storage end; the photovoltaic unit includes a photovoltaic panel (2) installed on the roof of the cowshed (1), the photovoltaic panel (2) is connected to an inverter control unit (3), which converts the DC power generated by the photovoltaic panel (2) into AC power; the inverter control unit (3) and the power grid unit (4) supply power to the cooling and cold storage end via the frequency converter (5); the power supply end has a built-in photovoltaic power acquisition unit for collecting photovoltaic power data; The refrigeration storage end includes a compressor (6), a condenser (7), a throttle valve (8), an evaporator (9), a cooling tower (10), a cooling pump (11), an ice storage tank (12), a plate heat exchanger (13), a chilled water pump (14), a fan coil unit (15), an ethylene glycol circulation pump (17), and an electric three-way diverter valve (18); the compressor (6) of the refrigeration storage end is electrically connected to the frequency converter (5); the compressor (6), condenser (7), throttle valve (8), and evaporator (9) are connected in sequence through pipes to form a dual-condition refrigeration host (16), forming a refrigerant circulation loop; the condenser (7), cooling tower (10), and cooling pump (11) are connected in sequence through pipes to form a closed loop, forming a cooling water circulation loop; the evaporator (9) is connected to the electric three-way diverter valve (18), and the electric three-way diverter valve (18) is connected to the evaporator (9). The two outlets of 18) are respectively connected to the parallel cooling branch and the ice storage branch: the cooling branch is connected to the ethylene glycol side inlet of the plate heat exchanger (13), and the ice storage branch is connected to the heat exchange coil inlet of the ice storage tank (12); after the outlet of the ethylene glycol side of the plate heat exchanger (13) and the outlet of the heat exchange coil of the ice storage tank (12) merge, they flow back to the evaporator (9) through the ethylene glycol circulation pump (17) to form an ethylene glycol refrigerant circulation loop; the chilled water side of the plate heat exchanger (13), the chilled water pump (14), and the fan coil unit (15) are connected in sequence through pipes to form a closed loop, constituting an air conditioning chilled water circulation loop; the controlled end of the electric three-way diverter valve (18) is bidirectionally connected to the monitoring and control end for dynamically distributing the flow direction and flow rate of the low-temperature ethylene glycol solution; the refrigeration storage end is equipped with an ice storage sensor acquisition unit for collecting ice storage data; The air supply end includes a perforated air duct (20) located above the cow bed (21); the perforated air duct (20) is connected to the cold air outlet of the fan coil unit (15) of the refrigeration and cold storage end, and delivers low-temperature air to the cow bed (21) through the perforated air duct (20). The monitoring and control terminal includes a signal acquisition unit and a control output unit. The signal acquisition unit is connected to temperature sensors, relative humidity sensors, solar radiation sensors, ice storage sensor acquisition units and photovoltaic power acquisition units that are distributed inside and outside the cow shed. It is used to collect environmental parameters inside and outside the dairy cow shed in real time, and calculate and classify the temperature and humidity index (THI) based on the collected temperature and relative humidity data. ; Where T is temperature in Celsius; RH is relative humidity percentage; The control output unit includes an EMS energy management control component and an industrial communication component, which are bidirectionally connected to the controlled ends of the power supply end and the refrigeration and cold storage end, respectively. It generates and issues control commands based on THI level, photovoltaic output data, and ice storage data, thereby controlling the power supply end to switch power supply modes and the refrigeration and cold storage end to switch operating modes, adapting to different dairy shed cooling scenarios.

2. The photovoltaic-ice storage cooling environment control system for dairy barns according to claim 1, characterized in that, The perforated duct (20) is provided with an array of holes with gradually changing diameter and spacing along its length to achieve approximately constant airflow. The duct wall of the perforated duct (20) is provided with an array of holes with gradually changing diameter and spacing along its length, and the opening direction is at a 15° angle to the vertical direction towards the cow bed (21). Each perforated duct (20) has a double-layer insulation structure with an insulation interlayer between its inner and outer layers to reduce the cold bridge effect. The perforated air duct (20) is equipped with a replaceable perforated plate or an adjustable air outlet sleeve to adapt to the heat and humidity load of cattle sheds in different areas. The lowest point of the perforated duct (20) is provided with a drainage hole, which is connected to the ground drainage ditch through a flexible hose to prevent condensation from dripping onto the cow's body.

3. A method for controlling the photovoltaic-ice storage cooling environment in a dairy barn, based on the control system described in any one of claims 1-2, characterized in that, The power supply modes at the power supply end include photovoltaic power generation, photovoltaic power generation + grid power supply, and grid power supply. The refrigeration and cold storage terminal operation modes include refrigeration + ice storage, refrigeration, refrigeration + ice melting, ice storage, and ice melting; The THI classification levels are: low, medium, and high, corresponding to no, mild, and moderate to severe heat stress states in dairy cows, respectively. When the THI level is low, the monitoring and control terminal adjusts the power supply to "photovoltaic power generation" mode, supplying power solely to the photovoltaic units. When the photovoltaic power is sufficient and a warning of a THI level increase is received, the cooling and cold storage terminal is adjusted to ice storage mode. If the THI level is predicted to rise to mild heat stress, ice storage is maintained until the ice storage volume reaches the upper limit of the conventional ice storage target. If the THI level is predicted to rise to moderate to severe heat stress, ice storage is maintained until the ice storage volume reaches the lower limit of the preventive ice storage target. When the photovoltaic power is sufficient, there is no warning of a THI level increase, and the ice storage volume has not reached the lower limit of the conventional ice storage target, the cooling and cold storage terminal is adjusted to ice storage mode until the ice storage volume reaches the lower limit of the conventional ice storage target, then the cooling and cold storage terminal is adjusted to standby mode. When the photovoltaic power is insufficient, the cooling and cold storage terminal is adjusted to standby mode. When the THI (Total Hidden Heating) level is at the intermediate level, the monitoring and control terminal first determines whether the photovoltaic power is sufficient. If the photovoltaic power is sufficient and a THI level escalation warning is received, the power supply terminal is adjusted to "Photovoltaic Power Generation" mode, with the photovoltaic units supplying power independently. Simultaneously, it is determined whether the ice storage capacity has reached the lower limit of the preventive ice storage target. If the ice storage capacity has not reached the target, the cooling and cold storage terminal is adjusted to "Cooling" or "Cooling + Ice Storage" mode to prioritize meeting the real-time cooling needs of the cattle shed. The remaining cooling capacity is used for ice storage until the ice storage capacity reaches the preventive ice storage target. Then, the cooling and cold storage terminal is adjusted to "Cooling" mode. If the photovoltaic power is sufficient and there is no THI level escalation warning, the power supply terminal is adjusted to "Photovoltaic Power Generation" mode, with the photovoltaic units supplying power independently. Simultaneously, it is determined whether the ice storage capacity has reached the target. If the ice storage capacity falls below the lower limit of the conventional ice storage target, the cooling and cold storage end is adjusted to "cooling" or "cooling + ice storage" mode to prioritize meeting the real-time cooling needs of the cattle shed. Excess cooling capacity is used for ice storage until the ice storage capacity reaches the upper limit of the conventional ice storage target. Then, the cooling and cold storage end is adjusted to "cooling" mode. If the photovoltaic power is insufficient, it is determined whether the ice storage capacity is greater than the minimum safe ice storage capacity. If the ice storage capacity is greater than the minimum safe ice storage capacity, the cooling and cold storage end is adjusted to "cooling + ice melting" or "ice melting" mode to prioritize using ice storage to supplement the cooling capacity gap. If the ice storage capacity is less than or equal to the minimum safe ice storage capacity, the power supply end is adjusted to "photovoltaic power generation + grid power supply" mode, and the cooling and cold storage end is adjusted to "cooling" mode to ensure the basic cooling needs of the cattle shed. When THI is at an advanced level, the monitoring and control terminal first determines whether the photovoltaic power is sufficient. If the photovoltaic power is sufficient, the power supply terminal is adjusted to the "photovoltaic power generation" mode, and the photovoltaic units supply power independently. Simultaneously, the ice storage status is determined: the cooling and cold storage terminal is adjusted to the cooling mode. If there is a surplus in the real-time cooling load, ice storage is added simultaneously until the ice storage reaches the preventive ice storage target. If there is still a cooling gap under extreme high load, the "ice melting" mode is activated to provide supplementary cooling. If the photovoltaic power is insufficient, the power supply terminal is adjusted to the "photovoltaic power generation + grid power supply" mode, with the photovoltaic units supplying power first, and the power gap being filled by the grid. Simultaneously, the ice storage status is determined: if the ice storage is greater than the minimum safe ice storage, the cooling and cold storage terminal is adjusted to the "cooling + ice melting" mode or the "ice melting" mode to maximize the use of cold storage to supplement the cooling gap and reduce grid power consumption. If the ice storage is less than or equal to the minimum safe ice storage, the cooling and cold storage terminal is adjusted to the cooling mode to ensure the cooling needs of the cattle shed under severe heat stress.

4. The control method according to claim 3, characterized in that, The operation mode of the refrigeration and cold storage end is controlled by the monitoring and control terminal, as follows: When the dual-mode host (16) is in operation, the power supply drives the compressor (6) to compress the refrigerant to a high temperature and high pressure gaseous state and then enters the condenser (7). After being cooled by the cooling water circulated by the cooling pump (11) and cooling tower (10), the refrigerant condenses into a high pressure liquid state. After being throttled by the throttling valve (8), the pressure is reduced to a low temperature and low pressure gas-liquid mixture, which enters the evaporator (9) to absorb heat and cool down the ethylene glycol solution in the evaporator. The monitoring and control terminal dynamically distributes the flow direction of the low-temperature ethylene glycol solution through an electric three-way diverter valve (18), and controls the refrigeration and cold storage terminal to switch between the following operating modes: When the system is in "ice storage" mode, the monitoring and control terminal controls the cooling pump (11) and cooling tower (10) to run synchronously. The electric three-way diversion valve (18) shuts off the cooling branch and opens the ice storage branch. The ethylene glycol circulation pump (17) drives all the low-temperature ethylene glycol to flow into the ice storage tank (12). Through heat exchange, the water outside the coil freezes, and all the photovoltaic power is converted into cold energy and stored in the form of ice, thus completing ice making and cold storage. When the system is in the "cooling + ice storage" mode, the monitoring and control terminal controls the dual-condition host (16), cooling pump (11), cooling tower (10), ethylene glycol circulation pump (17), chilled water pump (14) and fan coil unit (15) to operate synchronously. The electric three-way diversion valve (18) simultaneously connects the cooling supply branch and the ice storage branch. The low-temperature ethylene glycol prepared by the evaporator (9) prioritizes the flow of the cooling supply branch and enters the plate heat exchanger (13) to prepare chilled water. It is then supplied to the cowshed for cooling through the fan coil unit (15). The low-temperature ethylene glycol that exceeds the real-time cooling demand enters the ice storage branch and enters the metal coil of the ice storage tank (12), causing the water outside the coil to freeze, thus completing the ice making and cold storage, and converting the remaining photovoltaic power into the latent heat of phase change of ice. When the system is in "cooling" mode, the monitoring and control terminal controls the dual-condition host (16), cooling pump (11), cooling tower (10), ethylene glycol circulation pump (17), chilled water pump (14) and fan coil unit (15) to run synchronously. The electric three-way diversion valve (18) shuts off the ice storage branch and opens the cooling branch. All low-temperature ethylene glycol cooling branches prepare low-temperature chilled water through plate heat exchanger (13) and then supply cooling to the cowshed through fan coil unit (15). When the system is in the "cooling + ice melting" mode, the monitoring and control terminal controls the dual-condition host (16), cooling pump (11), cooling tower (10), ethylene glycol circulation pump (17), chilled water pump (14) and fan coil unit (15) to run synchronously. The electric three-way diversion valve (18) opens the cooling branch and the ice storage branch. The low-temperature ethylene glycol directly supplied by the dual-condition host (16) enters the cooling branch and the ice storage branch simultaneously through the electric three-way diversion valve (18). The low-temperature ethylene glycol after melting ice in the ice storage tank (12) and the ethylene glycol after heat exchange through the cooling branch merge and flow back to the evaporator (9) through the ethylene glycol circulation pump (17) to jointly provide cooling for the cattle shed. When the system is in "ice melting" mode, the dual-mode main unit (16) stops running and only the ethylene glycol circulation pump (17), chilled water pump (14) and fan coil unit (15) are started. The ethylene glycol circulation pump (17) drives the ethylene glycol solution into the ice storage tank (12), and is cooled into a low-temperature ethylene glycol solution by absorbing the cold energy of the melting ice layer. The low-temperature ethylene glycol is sent to the plate heat exchanger (13) through the ethylene glycol circulation pump (17) to prepare low-temperature chilled water, which is then supplied to the cattle shed for cooling through the fan coil unit (15). The ethylene glycol that has been heated by heat exchange flows back to the ethylene glycol circulation pump (17), forming an independent ice melting and cooling closed loop.

5. The control method according to claim 3, characterized in that, The THI classification is as follows: THI<72 is low, 72≤THI<79 is medium, and THI≥79 is high, corresponding to no, mild, and moderate to severe heat stress states in dairy cows, respectively.

6. The control method according to claim 3, characterized in that, Sufficient photovoltaic power is defined as real-time output power of the photovoltaic unit ≥ 60% of the rated operating power of the cooling and cold storage end; insufficient photovoltaic power is defined as real-time output power of the photovoltaic unit < 60% of the rated operating power of the cooling and cold storage end. With the rated maximum ice storage capacity of the ice storage tank as 100%, the entire ice storage capacity range is divided into three control threshold ranges, as follows: Level 1 lower limit safety control range: 0% ≤ ice storage capacity < 20%, of which 15% is the minimum safe ice storage critical value, which is the lower limit protection threshold for ice melting and cooling, used for safety protection and control when the ice storage capacity is too low; Level 2 daily control range: 20% ≤ ice storage capacity < 90%, of which 60%~80% is the target ice storage range for normal operating conditions, used for cold storage capacity regulation under normal operating conditions; Level 3 extreme working condition preventive control range: 90%≤ice storage capacity≤100%, used for early warning of extreme high temperature and advance cold storage control under continuous high radiation conditions.

7. The control method according to claim 6, characterized in that, The target ice storage capacity can be adjusted based on the herd's lactation cycle, stocking density, and milk production rhythm.

8. The control method according to claim 3, characterized in that, Based on weather forecasts of temperature and humidity data and photovoltaic power generation prediction data, the monitoring and control system calculates the THI (Heat Intake) trend in dairy barns within a set time period. When a predicted increase in THI is expected, the target ice storage capacity is adjusted upwards within the set timeframe: if the predicted THI increases to mild heat stress, the target ice storage capacity is adjusted to 80% of the upper limit of the regular ice storage target; if the predicted THI increases to moderate to severe heat stress / extreme high temperature conditions, the target ice storage capacity is adjusted to 90% of the lower limit of the preventative ice storage target; if the predicted THI decreases to below the low-level heat stress threshold in the future, the target ice storage capacity is adjusted downwards to 60% of the lower limit of the regular ice storage target. When it is predicted that the THI (Heat Intake) of the dairy barn will remain in a stable state of heat stress for a set period of time, and the predicted output of photovoltaic power generation during the corresponding period is continuously lower than 30% of the rated power of the cooling and cold storage end, the monitoring and control terminal will lower the target ice storage capacity to 60% of the lower limit of the conventional ice storage target to reduce system energy consumption; after the target ice storage capacity is lowered, the real-time ice storage capacity shall not be lower than the minimum safe ice storage capacity.

9. The control method according to claim 3, characterized in that, The control method is based on the photovoltaic power generation period and the real-time heat load of the cattle shed, and the monitoring and control terminal performs differentiated operation and control according to the season. Specifically: Summer operating conditions: During the daytime when the solar radiation intensity is at a medium / high level, the system will prioritize switching to the "photovoltaic power generation" mode, driving the cooling and cold storage end to simultaneously execute the "cooling + ice storage" mode—prioritizing the real-time cooling demand of the cattle shed. Any remaining cooling capacity of the cooling and cold storage end beyond the real-time cooling demand will be used for ice production and cold storage in the ice storage tank. During the nighttime when there is no effective solar radiation, the cold storage capacity of the ice storage tank will be used to execute the "ice melting + cooling" mode. Only when the ice storage capacity is less than or equal to the minimum safe ice storage capacity and the temperature and humidity index (THI) of the cattle shed exceeds the medium heat stress threshold will the "grid power supply" be supplemented to drive the cooling. Transitional season operating conditions: When the real-time THI of the cattle shed reaches the medium level or above, ice storage is only added during the day when the photovoltaic power is sufficient and there is a surplus in cooling demand, and the dual-condition main unit is stopped at night. Winter operating conditions: Stop the ice-making and refrigeration operation of the cold storage end, and only regulate the ambient temperature and humidity through the cattle shed ventilation system. When the relative humidity in the shed is >80%, the dehumidification mode can be turned on for a short time.

10. The control method according to claim 3, characterized in that, The control thresholds for the cowshed environment in the control method are as follows: the environmental temperature control threshold for the cowshed activity area can be set from 8℃ to 26℃ according to the breed of dairy cow and the lactation cycle, of which the upper limit for heat stress prevention and control is 26℃ and the lower limit for low temperature protection is 8℃; the target for relative humidity control in the cowshed environment is 50% to 75%.

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