An integrated water chiller operating under extreme conditions

Abstract

The utility model discloses an integral type water chilling unit under the operation of extreme working condition, including the fan of upper part, air -cooled finned -type condenser and the refrigerating unit of lower part, and the refrigerating unit is equipped with refrigerant circulation system and refrigerated water circulation system, refrigerant circulation system includes the compressor, air -cooled finned -type condenser, electronic expansion valve and evaporator that connect gradually, refrigerated water circulation system includes the buffer water tank, water pump and evaporator that connect gradually, electronic expansion valve is connected with drying filter cartridge, evaporator, and drying filter cartridge is connected with liquid storage tank, and evaporator is connected with gas -liquid separator, the utility model discloses using PWM and stepless regulation multidimension collaborative control, realizes stable operation when the energy efficiency of wide temperature field is suddenly reduced, in the high temperature side, and condensing fan adopts stepless speed regulation technology, and low temperature side is switched to PWM period regulation mode.

Description

Technical Field

[0001] This utility model relates to the field of refrigeration technology, and in particular to an integrated chiller unit that operates under extreme conditions. Background Technology

[0002] Air-cooled screw chillers are based on the principle of vapor compression refrigeration, achieving a refrigeration cycle through the coordinated action of a screw compressor, an air-cooled condenser, a throttling device, and an evaporator. The core workflow is as follows: the screw compressor compresses the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gas, which is then transported to the air-cooled condenser and cooled into a high-pressure liquid state through forced air convection. The liquid refrigerant, after being depressurized by the throttling device, enters the evaporator, absorbs heat from the chilled water, and vaporizes into a low-temperature, low-pressure gas, ultimately returning to the compressor to complete the cycle.

[0003] Existing technology, such as an outdoor cabinet for wind-cooled electronic equipment resistant to harsh environments (CN119031669A), discloses an outdoor cabinet for wind-cooled electronic equipment resistant to harsh environments. The cabinet body adopts a frame structure, and the outer surface skin is a continuous sealed structure. The front and rear doors are hinged to the cabinet body and locked with door locks. Conductive sealing strips are installed between the door frames and the cabinet body for sealing. The front door of the cabinet body is a ventilation and heat dissipation area, and the rear door of the cabinet body is a sealed area. The ventilation and heat dissipation area and the sealed area are separated by a back panel. Electronic equipment that needs to be cooled is installed in the ventilation and heat dissipation area, while components that do not need to be cooled are installed in the sealed area. The bottom of the ventilation and heat dissipation area is an air inlet, and the top of the cabinet body has an air outlet. This solves the problem of outdoor cabinets for electronic equipment that need to meet the requirements of open-type wind-cooling and heat dissipation and have good environmental adaptability.

[0004] However, when operating under extreme conditions, chiller units face two challenges: large temperature differences throughout the year and rain, snow, and sandstorms.

[0005] When there are large temperature differences throughout the year, air-cooled screw chiller units face systemic challenges. High temperatures cause condensing pressure to surge, leading to compressor discharge temperatures exceeding limits, increasing the risk of lubricating oil carbonization, and insufficient heat dissipation of electronic components causing control board malfunctions. Low temperatures cause a surge in lubricating oil viscosity, leading to refrigerant migration and liquid slugging, which can easily cause evaporator copper tubes to freeze and rupture, and metal materials to become embrittled, resulting in flange weld cracking. Throttling devices typically adjust the throttling degree based on the evaporator outlet superheat; excessively low condensing pressure interferes with this process, causing traditional PID control to lag, resulting in frequent compressor starts and stops or prolonged deviations from the high-efficiency range, accelerating wear on core components.

[0006] In rainy, snowy, and dusty environments, large particles such as sand and dust can easily clog the gaps between condenser fins, leading to reduced airflow and triggering high-pressure alarms. During heavy rainfall, water flow impacts the fins, causing aluminum foil to collapse and copper pipe welds to corrode and perforate. Simultaneously, rainwater seeps into the fan bearings, causing lubrication failure. Snow covering the fin surface forms an insulation layer, reducing the heat exchange temperature difference, and repeated freezing and expansion of melting snow can cause the fin's window-like structure to break. Sand and dust carry salt that adheres to the fin surface, forming an electrolyte with condensate and accelerating electrochemical corrosion. Sand and dust intrusion into the electrical control cabinet can cause short circuits in electrical components and increase contactor contact resistance. The combined effects of extreme weather conditions increase the unit's annual average failure rate and reduce energy efficiency.

[0007] Therefore, it is necessary to develop new integrated chiller units that operate under extreme conditions to overcome the above problems. Utility Model Content

[0008] Purpose of this utility model: To address the shortcomings and defects of existing technologies, this utility model provides an integrated chiller unit that operates under extreme conditions. It utilizes PWM and stepless speed control for multi-dimensional coordinated control, achieving stable operation even when energy efficiency drops sharply across a wide temperature range. On the high-temperature side, the condenser fan employs stepless speed regulation technology, dynamically adjusting its speed based on the condensing pressure sensor signal. The fan operates at high speed to enhance heat dissipation, ensuring stable condensing temperature and minimal pressure fluctuations. Simultaneously, the electronic expansion valve compensates for refrigerant flow, preventing the compressor discharge temperature from exceeding limits. On the low-temperature side, it switches to PWM periodic regulation mode, reducing the fan frequency to the lowest speed or intermittently starting and stopping to maintain condensing pressure and prevent excessive lubricating oil viscosity. Combined with the electronic expansion valve's closed-loop overheat control and compressor slide valve adjustment, it achieves evaporator-side antifreeze protection and precise cooling output.

[0009] Technical Solution: This utility model discloses an integrated chiller unit operating under extreme conditions, characterized in that it comprises an upper part consisting of a fan and an air-cooled finned condenser, and a lower part consisting of a refrigeration unit. The refrigeration unit is equipped with a refrigerant circulation system and a chilled water circulation system. The refrigerant circulation system includes a compressor, an air-cooled finned condenser, an electronic expansion valve, and an evaporator connected in sequence. The chilled water circulation system includes a buffer tank, a water pump, and an evaporator connected in sequence. The electronic expansion valve is connected to a drying filter cartridge and an evaporator, the drying filter cartridge is connected to a liquid storage tank, and the evaporator is connected to a gas-liquid separator.

[0010] The air-cooled finned condenser has a grid on the air inlet side, and the grid is a V-shaped dustproof grille.

[0011] The buffer water tank is equipped with an overflow outlet, a water inlet, and a sewage outlet.

[0012] The air-cooled finned condenser is equipped with a water inlet, a water outlet, and a water flow switch.

[0013] The air-cooled finned condenser is provided with louvers on its side.

[0014] Beneficial Effects: Compared with the prior art, this utility model has the following significant advantages: 1) High efficiency and energy saving: It integrates frequency conversion drive, electronic expansion valve and compressor load coordinated control. Based on multi-sensor data fusion and adaptive algorithm, it automatically identifies abnormal working conditions, switches to backup strategies to ensure continuous operation, quickly responds to load fluctuations, reduces energy consumption peak-valley difference, and maintains optimal efficiency under all working conditions. 2) Reliable operation: The system has built-in antifreeze, anti-overheating and anti-corrosion functions for extreme conditions, reducing the risk of system failure. By strengthening the speed regulation range of the condenser fan and selecting low-temperature resistant materials, it achieves a two-way balance between high-temperature heat dissipation and low-temperature antifreeze, which can adapt to various complex and changing operating environments and ensure stable operation and efficient cooling effect of the equipment.

[0015] This invention features a V-shaped dustproof grille installed on the air inlet side of the condenser, which separates PM50+ particles through inertial impaction and includes a quick-release structure for easy cleaning. A rain and snow guide is located at the top, and a drainage channel at the bottom directs rain and snow runoff away from the fin area. The grille and guide device are coated with epoxy resin, making them resistant to salt spray corrosion, reducing maintenance frequency and extending fin life. The system integrates a low-temperature lubricating oil heater and refrigerant migration suppression logic, supplemented by a liquid storage tank and a gas-liquid separator. Finally, an intelligent controller integrates multi-parameter prediction algorithms based on ambient temperature, pressure, flow rate, and other parameters to meet the reliable cooling needs of harsh environments such as deserts and polar regions. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model;

[0017] Figure 2 This is a diagram of the internal system of this utility model;

[0018] In the diagram, 1 is the fan; 2 is the air-cooled finned condenser; 3 is the overflow outlet; 4 is the water inlet; 5 is the water inlet; 6 is the water outlet; 7 is the gas-liquid separator; 8 is the grid; 9 is the flow switch; 10 is the evaporator; 11 is the liquid storage tank; 12 is the compressor; 13 is the water pump; and 14 is the louver. Detailed Implementation

[0019] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0020] This utility model discloses an integrated chiller unit operating under extreme conditions, comprising an upper fan 1, an air-cooled finned condenser 2, and a lower refrigeration unit. The refrigeration unit is equipped with a refrigerant circulation system and a chilled water circulation system. The refrigerant circulation system includes a compressor 12, an air-cooled finned condenser 2, an electronic expansion valve, and an evaporator 10 connected in sequence. The chilled water circulation system includes a buffer tank, a water pump 13, and an evaporator 10 connected in sequence. The electronic expansion valve is connected to a drying filter cartridge and the evaporator 10. The drying filter cartridge is connected to a liquid storage tank 11. The evaporator 10 is connected to a gas-liquid separator 7. The air-cooled finned condenser 2 has a grid 8 on its air inlet side, which is a V-shaped dustproof grille. The buffer tank has an overflow port 3, a water inlet 4, and a drain port. The air-cooled finned condenser 2 has a water inlet 5, a water outlet 6, and a flow switch 9. The air-cooled finned condenser 2 has louvers 14 on its side.

[0021] This integrated chiller unit operates under extreme conditions. In the refrigerant cycle, the low-temperature, low-pressure gaseous refrigerant first enters the compressor 12, where it is compressed into a high-temperature, high-pressure gas by rotor meshing. It then enters the air-cooled finned condenser 2, where a fan 1 drives forced convection cooling of the ambient air, causing the refrigerant to condense into a medium-temperature, high-pressure liquid. The liquid refrigerant flows through the electronic expansion valve, where its opening is adjusted to achieve adiabatic expansion, forming a low-temperature, low-pressure gas-liquid two-phase flow. This flow enters the shell-and-tube evaporator 10, absorbing heat from the chilled water and completely vaporizing. Finally, it returns to the compressor 12 to complete the cycle. The oil circuit system operates synchronously. The lubricating oil discharged from the compressor 12 is collected by an oil separator, cooled by an oil cooler, and then recirculated into the compressor bearings and rotor cavity for lubrication, ensuring low-wear operation of moving parts.

[0022] In the chilled water circulation, the ambient temperature chilled water in the buffer tank is driven by the water pump 13, flows through the evaporator 10, exchanges heat with the low temperature refrigerant and then the temperature drops to the required range. It is then delivered to the user-end equipment to absorb heat. After the temperature rises, the return water is filtered and purified and then re-enters the evaporator 10 for circulation. The system ensures that the heat exchange temperature difference in the evaporator 10 is within a reasonable range by adjusting the water flow rate, so as to avoid the risk of freezing.

[0023] This utility model relates to an integrated chiller unit that operates under extreme conditions. It adopts both frequency conversion regulation mode and PWM regulation mode. During operation, it detects the outdoor dry-bulb temperature and condensing temperature, automatically determines whether the switching conditions have been met, and automatically switches between frequency conversion regulation mode and PWM regulation mode.

[0024] In high-temperature environments, the variable frequency control mode is automatically switched. Fan 1 dynamically adjusts its speed according to the condensing pressure sensor signal, and runs at high speed to enhance heat dissipation, ensuring stable condensing temperature and small pressure difference fluctuations. At the same time, the opening of the electronic expansion valve is used to compensate for the refrigerant flow and prevent the discharge temperature of compressor 12 from exceeding the limit.

[0025] In low-temperature environments, the system automatically switches to PWM cycle adjustment mode. When the fan frequency is adjusted to the lowest fan speed, fan 1 switches to PWM adjustment and automatically switches to the initial duty cycle of 0.8, which means running for 4 minutes and then stopping for 1 minute. If the condensing pressure still drops according to this cycle, the duty cycle decreases; otherwise, the duty cycle increases. This, combined with the superheat closed-loop control of the electronic expansion valve and the adjustment of the compressor 12 slide valve, maintains the condensing pressure to prevent the lubricating oil viscosity from becoming too high, thus achieving evaporator-side antifreeze protection and precise output of cooling capacity.

[0026] The chilled water pump does not stop when the unit is in standby mode; after the unit stops, the chilled water pump and cooling fan shut down after a delay.

[0027] This utility model offers the following advantages: 1) High efficiency and energy saving: It integrates variable frequency drive, electronic expansion valve, and compressor load coordinated control. Based on multi-sensor data fusion and adaptive algorithms, it automatically identifies abnormal operating conditions, switches to backup strategies to ensure continuous operation, quickly responds to load fluctuations, reduces energy consumption peak-to-valley differences, and maintains optimal efficiency across all operating conditions. 2) Reliable operation: The system incorporates antifreeze, anti-overheating, and anti-corrosion functions for extreme conditions, reducing the risk of system failure. By enhancing the condenser fan speed range and selecting low-temperature resistant materials, it achieves a two-way balance between high-temperature heat dissipation and low-temperature antifreeze, adapting to various complex and changing operating environments and ensuring stable equipment operation and efficient cooling.

[0028] This invention features a V-shaped dustproof grille installed on the air inlet side of the condenser, which separates PM50+ particles through inertial impaction and includes a quick-release structure for easy cleaning. A rain and snow guide is located at the top, and a drainage channel at the bottom directs rain and snow runoff away from the fin area. The grille and guide device are coated with epoxy resin, making them resistant to salt spray corrosion, reducing maintenance frequency and extending fin life. The system integrates a low-temperature lubricating oil heater and refrigerant migration suppression logic, supplemented by a liquid storage tank and a gas-liquid separator. Finally, an intelligent controller integrates multi-parameter prediction algorithms based on ambient temperature, pressure, flow rate, and other parameters to meet the reliable cooling needs of harsh environments such as deserts and polar regions.

Claims

1. An integrated water chiller for operation in extreme conditions, characterized in that: The unit includes a fan (1) and an air-cooled finned condenser (2) in the upper part and a refrigeration unit in the lower part. The refrigeration unit is equipped with a refrigerant circulation system and a chilled water circulation system. The refrigerant circulation system includes a compressor (12), an air-cooled finned condenser (2), an electronic expansion valve and an evaporator (10) connected in sequence. The chilled water circulation system includes a buffer water tank, a water pump (13) and an evaporator (10) connected in sequence. The electronic expansion valve is connected to a drying filter cartridge and an evaporator (10). The drying filter cartridge is connected to a liquid storage tank (11). The evaporator (10) is connected to a gas-liquid separator (7).

2. The integrated water chiller operating under extreme conditions according to claim 1, wherein: The air-cooled finned condenser (2) is provided with a grid (8) on the air inlet side, and the grid (8) is a V-shaped dustproof grid.

3. The integrated water chiller operating under extreme conditions according to claim 1, wherein: The buffer tank is equipped with an overflow outlet (3), a water inlet (4), and a sewage outlet.

4. The integrated water chiller operating under extreme conditions of claim 1, wherein: The air-cooled finned condenser (2) is provided with a water inlet (5), a water outlet (6) and a water flow switch (9).

5. The integrated chiller unit operating under extreme conditions according to claim 1, characterized in that: The air-cooled finned condenser (2) is provided with louvers (14) on its side.

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