A cooling system combining evaporative condensation of outdoor unit of computer room with natural cold source

Abstract

This invention discloses a combined evaporative condensation and natural cold source cooling system for outdoor units in computer rooms, belonging to the field of computer room cooling equipment. The system features a vertical tower shell with a conical equal-volume water distributor, modular packing, a Teflon-coated film distributor, and a falling film heat exchanger arranged from top to bottom. A louvered air inlet is located between two heat exchangers in the shell, and a suspended, submerged refrigerant-cooled condensing coil is placed in a water tank below the air inlet. The water tank supplies water to the top water distributor via a single-path return water pipe and a circulating water pump. The shell has three independent maintenance ports for the fan, heat exchangers, and water tank. The conical water distributor achieves low-pressure, uniform water distribution, and the air inlet in the middle of the interlayer prevents the refrigerant coil from obstructing the air-cooling path, significantly reducing fan resistance. The system can switch between summer evaporative condensation and winter natural cooling single-pump operation modes for energy saving. The heat exchangers can be individually hoisted and disassembled without refrigerant recovery. The entire unit has a compact structure, simple maintenance, and significant energy-saving effect, suitable for computer room cooling above 0°C.

Description

Technical Field

[0001] This invention belongs to the field of computer room outdoor unit cooling technology, and in particular relates to a cooling system that combines evaporation and condensation with natural cold source for computer room outdoor units. Background Technology

[0002] Cooling of outdoor units in existing computer rooms typically uses cooling towers. Traditional cooling towers are mainly closed-loop cooling towers, which usually consist of an independent water distributor, evaporative cooling unit, condenser chiller, and corresponding piping connections. These types of cooling towers all rely on water distributors. Traditional water distributors are mainly of two types: spray nozzle type, which relies on the pressure provided by a water pump and has high energy consumption; and gravity pool type, which relies on its own gravity, distributing more water closer to the water pipe, which easily leads to uneven water distribution when the water volume changes. Moreover, regardless of whether it's a spray nozzle type or a gravity pool type, the closer to the water pipe inlet or the water pipe itself, the more water it receives, and the further away, the less water it receives, resulting in uneven water distribution. Because the structure of the water distributor occupies a large space in the cooling tower, the overall height of the cooling tower equipment is very high. Furthermore, the numerous connecting pipes between the evaporator / condenser and the water distributor make the linkage control relatively complex, resulting in high manufacturing costs for the entire system. In addition, the water distributor increases the power of the spray water pump, requiring continuous high-pressure water supply to achieve uniform water distribution through the falling film, leading to high energy consumption.

[0003] To address this, the improved cooling tower integrates the condenser coil and the cooling tower into a single unit, saving space. The evaporative cooling unit can produce high-temperature chilled water below the ambient wet-bulb temperature, which can be supplied to the end of the plate heat exchanger cooling room for return water. Simultaneously, it allows the mechanical refrigeration condensing temperature to remain below the ambient wet-bulb temperature. Considering winter operation and anti-freezing measures, a preheating device is added to the air inlet. Compared to traditional cooling towers, this improved cooling tower enhances the stability of the unit's cooling and solves the winter cooling and anti-freezing problems; however, its disadvantages include a complex structure, a large footprint, and the added preheating device further complicates the overall system structure, increasing both the footprint and piping, making maintenance more difficult.

[0004] Besides closed-circuit cooling towers, there are also composite cooling towers. Composite cooling towers do not use evaporative condensers, but instead use fluorinated refrigerant heat exchangers. In nuclear power projects or other similar projects where heat exchange components need to be frequently hoisted and maintained, the refrigerant needs to be recovered after the fluorinated refrigerant heat exchanger is installed and then disassembled, which is complicated. Traditional composite cooling towers are difficult to separate the two sets of heat exchangers.

[0005] A search of the closest prior art to this application revealed that prior to this application, patent publication number CN113266478A, entitled "A Composite Evaporative Cooling Closed-Loop Cooling Tower," disclosed a vertical tower body with an axial flow fan at the top, and packing, falling film heat exchange coils, and a bottom water tank arranged from top to bottom. The water tank contains a submerged fluorine-cooled condensing coil, and water is circulated and sprayed through a water pump. This cooling device can achieve a mechanical refrigeration operation mode, but this structure has high energy consumption and is difficult to maintain.

[0006] In summary, existing technologies lack an integrated computer room cooling system that simultaneously addresses issues such as uneven water distribution, high fan resistance, complex heat exchanger maintenance, and high energy consumption under high and low temperature conditions. Summary of the Invention

[0007] The purpose of this invention is to solve the technical problems of complex overall structure and high energy consumption caused by the use of water distributors in existing cooling towers, and to provide a cooling system for outdoor units in computer rooms. It combines evaporation and condensation with natural cold sources, achieves low-pressure uniform water distribution through a conical equal-volume water distributor, adopts a sandwich-type middle air intake and a submerged structure of refrigerant coils to reduce fan resistance, and is equipped with layered independent maintenance ports to achieve heat exchanger disassembly and assembly without refrigerant recovery, thereby reducing energy consumption. It is very suitable for use in southern regions, especially in areas where the winter temperature is above zero degrees Celsius.

[0008] The objective of this invention is achieved through the following technical solution: A cooling system combining evaporation and condensation with natural cold source for an outdoor unit in a computer room, comprising a vertical tower structure shell, a variable frequency axial flow fan located at the top of the shell, a packing area, a film distributor, a falling film heat exchanger, a refrigerant-water heat exchanger, a water storage tank, a water pump, and a return water pipe; it also includes an equal volume water distributor, wherein the equal volume water distributor, modular packing area, detachable film distributor, falling film heat exchanger, and water storage tank are sequentially assembled from top to bottom inside the shell; a louvered air inlet is provided on the side wall of the shell below the falling film heat exchanger and above the water storage tank cavity, and a refrigerant-water heat exchanger is located below the air inlet; the equal volume water distributor is a one-piece conical structure, wider at the top and narrower at the bottom, horizontally arranged directly below the fan, and the bottom of the equal volume water distributor has matrix-style equidistant water distribution holes, each corresponding one-to-one with the packing material in the packing area below; the falling film heat exchanger, modular packing area, removable film distributor, falling film heat exchanger, and water storage tank are also included; the falling film heat exchanger, modular packing area, removable film distributor, falling film heat exchanger, and water storage tank are also included; a louvered air inlet is provided on the side wall of the shell below the falling film heat exchanger and above the water storage tank cavity, and a refrigerant-water heat exchanger is located below the air inlet; the equal volume water distributor is a one-piece conical structure, wider at the top and narrower at the bottom, horizontally arranged directly below the fan, and the bottom of the equal volume water distributor has matrix-style equidistant water distribution holes, each corresponding one-to-one with the packing material in the packing area below; the falling film heat exchanger, modular packing area, removable film heat exchanger, falling film heat exchanger, falling film heat exchanger, falling film heat exchanger, falling film heat exchanger, falling film The membrane heat exchanger is composed of multiple independent loop serpentine water coils stacked horizontally, with staggered high-temperature water inlets and low-temperature water outlets. The high-temperature water inlet is connected to the chilled water supply system of the machine room. The fluoride-water heat exchanger is composed of multiple sets of bare tube serpentine refrigerant condensing coils stacked together, suspended and submerged in the water body of the storage tank by a support. The fluoride-water heat exchanger has parallel high-temperature refrigerant inlets and low-temperature refrigerant outlets, with the high-temperature refrigerant inlet connected to a refrigeration compressor. The storage tank is a closed cavity at the bottom of the shell, and the bottom of the storage tank is connected to the equal-volume water distributor at the top through a return water pipe. The water pump is installed on the return water pipe. The shell has three independent maintenance ports: the top fan maintenance port, the side and middle heat exchanger maintenance port, and the side and bottom water tank maintenance port.

[0009] Preferably, the inlet port of the equal-volume water distributor is connected to the return water pipe, and the inlet port is equipped with a detachable filter screen; several equal-volume water distribution bodies are evenly arranged on the base of the water distributor, and the water distribution holes are set at the bottom of the water distribution bodies, and the water distribution holes are chamfered at 45°; the chamfered plate is evenly distributed with funnel-shaped water distribution holes; the diameter of the water distribution holes is 8mm and the hole spacing is 45mm, which corresponds one-to-one with the lower modular packing, thereby reducing the spray water supply pressure, evenly distributing water, and reducing the overall height of the equipment.

[0010] Preferably, the packing area uses modified PVC oblique corrugated modular packing, with each packing block measuring 300×300mm and 0.4mm thick, and a stainless steel support grid is installed at the bottom of the packing.

[0011] Preferably, the vertical gap between the membrane distributor and the top coil of the falling film heat exchanger below is ≥10mm, and the horizontal gap between the membrane distributor and the edge of the coil is ≥5mm, to ensure that a complete and continuous water film without dry areas is formed outside the tube; the diameter of the water distribution holes of the membrane distributor is ≥6mm and the hole spacing is ≥30mm, and the flared structure reduces scale adhesion.

[0012] Preferably, the falling film heat exchanger has a total of 6 layers of horizontal serpentine coils, each layer of coils is an independent heat exchange loop, and stainless steel support bars are set between every 2 rows of coils; the falling film heat exchanger is arranged directly above the louvered air inlet, and external cold air passes through the air inlet from bottom to top through the falling film heat exchanger and forms counter-current evaporative heat exchange with the spray water.

[0013] Preferably, the louvered air inlet has a louver angle of 45°, and the inner side of the air inlet is equipped with a sliding rail detachable filter screen, which is convenient for external removal and cleaning of dust and impurities.

[0014] Preferably, the distance between the top coil of the fluorine-water heat exchanger and the water surface is ≥30mm, the distance between the bottom coil of the fluorine-water heat exchanger and the bottom of the water tank is ≥50mm, the vertical distance between the centers of two adjacent layers of coils in the fluorine-water heat exchanger is 25mm, and the minimum net distance between the outer walls of the tubes is 9mm, allowing free convection of the water without heat exchange dead zones; the fluorine-water heat exchanger is submerged and arranged below the air inlet, without occupying the air-cooling passage, and the fan only needs to overcome the air resistance of the packing and falling film heat exchanger, reducing the overall energy consumption of the unit, and the two sets of heat exchangers can be hoisted, disassembled and repaired separately without the need to recover refrigerant.

[0015] Preferably, the water storage tank is equipped with a sight glass and a built-in level gauge. The sight glass integrates water level, water temperature, and water turbidity monitoring modules. A drain outlet is opened at the bottom of the water storage tank. The level gauge, the sight glass, and the circulating water pump are linked by a controller. When the water level is too low, an external water source is automatically added to stabilize the circulating water volume.

[0016] Preferably, the water storage tank is a closed cavity at the bottom of the shell, with a sight glass facing the water storage tank and a level gauge installed inside the water storage tank.

[0017] Preferably, the top fan access port is equipped with a hinged safety lock cover, and the middle heat exchanger access port is symmetrically located on both sides of the falling film heat exchanger, allowing direct disassembly and cleaning of the film distributor and coils; lifting lugs are provided at the four corners of the unit, and a single row of coils can be independently pulled out for replacement without disassembling the entire unit.

[0018] The system has a dual-mode operation logic: In summer, the spray, fan, and refrigerant refrigeration circuit are turned on, the refrigerant-water heat exchanger completes the refrigerant condensation, and the falling film heat exchanger cools the chilled water in the machine room; in winter mode when the outdoor temperature is 0~15℃, the refrigerant refrigeration circuit is turned off, only the circulating water pump is run, and the fan can be stopped to rely on natural cold source for cooling; when the outdoor temperature is below 0℃, the drain pipe and water tank are drained to prevent freezing.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: a cooling system for outdoor unit evaporation and condensation combined with natural cold source in computer room has a compact and efficient overall structure and has the following advantages:

[0020] 1. Adopting a conical equal-volume water distributor, the upper wide and lower narrow conical shape combined with a 45-degree chamfered matrix water distribution hole eliminates water flow eddies, resulting in more uniform water distribution. It eliminates the need for high-pressure water pump supply, reducing water pump power consumption. The water distributor is also lower in height, reducing the overall tower height and making it more adaptable to machine room installation. It overcomes the shortcomings of uneven water distribution and high water pump energy consumption of existing cooling towers.

[0021] 2. The dual-combination heat exchange of falling film heat exchanger and fluorine-water heat exchanger integrates the fluorine-water heat exchanger with the water tank. The fluorine-water heat exchanger does not interfere with the fan's air cooling. The fan exhaust only passes through two layers of resistance components: the packing and the falling film heat exchanger. Compared with existing cooling towers, the fan's air pressure loss is significantly reduced, and the fan's energy consumption is reduced in summer. The two heat exchangers are isolated in separate areas, and the fluorine coils can be hoisted separately through the central maintenance port. Maintenance does not require refrigerant recovery, solving the problem of complex disassembly and assembly of existing heat exchangers.

[0022] 3. The system's vertical design results in higher utilization of the cooling tower packing area;

[0023] 4. The fan, falling film heat exchanger, and water storage tank can be inspected and maintained in separate areas. The single-row coil can be removed and replaced individually, reducing the average annual maintenance cost compared to traditional cooling tower units. It also features a single integrated vertical single-pipe water circulation system with a simplified pipe structure, lower manufacturing costs, and simple linkage control logic, making it suitable for mass promotion in small and medium-sized computer rooms. Attached Figure Description

[0024] Figure 1 This is a simplified schematic diagram of the cooling system of the present invention.

[0025] Figure 2 This is a simplified structural diagram of the film distributor in the cooling system of this invention.

[0026] Figure 3 This is a simplified structural diagram of the falling film heat exchanger in the cooling system of this invention.

[0027] Figure 4 This is a simplified top view of the fluorine-water heat exchanger in the cooling system of this invention.

[0028] Figure 5 This is a simplified front view of the fluorine-water heat exchanger in the cooling system of this invention.

[0029] Figure 6 This is a simplified structural diagram of a single equal-volume water distributor in the cooling system of this invention.

[0030] Figure 7 This is a simplified top view of a single equal-volume water distributor in the cooling system of this invention.

[0031] Figure 8 This is a schematic diagram showing the connection of the water storage tank, return water pipe and equal volume water distributor in this invention.

[0032] In the attached diagram: 1. Fan; 2. Equal volume water distributor; 3. Packing area; 4. Film distributor; 41. Water distribution hole; 5. Falling film heat exchanger; 51. High temperature water inlet; 52. Low temperature water outlet; 53. Falling film heat exchange coil; 6. Air inlet; 7. Water surface sight glass; 8. Fluorine-water heat exchanger; 81. High temperature refrigerant inlet; 82. Low temperature refrigerant outlet; 83. Fluorine-water heat exchange coil; 9. Water storage tank; 91. Water storage tank cavity; 10. Water pump; 11. Return water pipe. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] like Figure 1-8 As shown, a cooling system combining evaporation and condensation with natural cold source is used in computer room outdoor units. This system is suitable for use in southern regions where the outdoor temperature is above 0 degrees Celsius. It includes a shell, a fan 1, an equal-volume water distributor 2, a packing area 3, a film distributor 4, a falling film heat exchanger 5, a refrigerant-water heat exchanger 8, a water storage tank 9, and a water pump 10. The shell is a vertical tower structure. The fan 1 is located at the top of the shell and is the power source for air circulation in the entire system, drawing air upwards from the tower. The equal-volume water distributor is vertically positioned directly below the fan; the two are arranged vertically opposite each other, and the negative pressure generated by the fan's suction guides the air inside the tower upwards. The equal volume water distributor 2, the packing area 3, the film distributor 4, the falling film heat exchanger 5, the fluorine water heat exchanger 8, and the water storage tank 9 are arranged sequentially from top to bottom inside the shell. An air inlet 6 is provided on the side wall of the shell located between the falling film heat exchanger 5 and the fluorine water heat exchanger 8. The fluorine water heat exchanger 8 is placed inside the cavity 91 of the water storage tank 9. The bottom of the water storage tank 9 is connected to the equal volume water distributor 2 through a return water pipe 11, and a water pump 10 is provided on the return water pipe 11. The entire system only requires one return water pipe, which saves manufacturing and maintenance costs.

[0035] The outer shell is made of galvanized steel sheet, and the outer frame of the outer shell is made of square tubes welded together, which has corrosion resistance.

[0036] The fan is an EC variable frequency axial flow fan. The EC variable frequency motor can steplessly adjust the speed according to the ambient temperature and heat exchange load, which greatly reduces the energy consumption under variable operating conditions compared with the fixed frequency fan. The fan is positioned at the top and draws air upward to create negative pressure inside the tower. Cold air flows counter-currently from bottom to top through the heat exchange components through the central louvered air inlet, while spray water flows from top to bottom. The counter-current air-water heat exchange maximizes the heat exchange temperature difference. The fan is equipped with a separate access panel with a safety lock hinge on the top. The motor and impeller can be inspected by opening the cover without disassembling the heat exchange components on the upper part of the tower.

[0037] Among them: such as Figure 6 , Figure 7 As shown, the equal-volume water distributor 2 is horizontally positioned at the top of the housing, and each distributor has a conical structure that is wider at the top and narrower at the bottom; this conical structure buffers the water pump's flow, eliminates water eddies in the pipeline, and, in conjunction with the 45° chamfered horn-shaped water distribution holes, achieves low-pressure uniform water distribution, eliminating the need for high-pressure water supply and reducing the power consumption of the circulating water pump.

[0038] The equal-volume water distributor is integrally molded, with a square stainless steel base and a DN40 water inlet at the top. The base is evenly distributed with 24 equal-volume water distribution elements, each corresponding to a specific area of ​​the packing material below, eliminating localized dry zones and maximizing the utilization of the heat dissipation packing. The equal-volume water distribution inlets use 8mm diameter stainless steel holes spaced 45mm apart in an equidistant matrix. The holes have a 45° chamfer. These dimensions and hole spacing were determined through experimentation, providing optimal and effective eddy current prevention. Furthermore, the integrated, low-profile conical structure significantly reduces the height compared to traditional pool water distributors and sprinkler water distributors, lowering the overall tower height and making it suitable for installation in low-ceilinged machine rooms.

[0039] like Figure 8 As shown, the inlet port of the equal-volume water distributor 2 is connected to the return water pipe 11, and the other end of the return water pipe is connected to the water storage tank 9 at the bottom of the entire cooling device. A water pump 10 is installed on the return water pipe to pump the water from the storage tank back into the top of the entire cooling device, and then the water flows downwards after being divided by the equal-volume water distributor. A filter screen is installed at the inlet port of the equal-volume water distributor 2 to intercept impurities in the water tank, prevent clogging of the water distribution holes, and reduce the frequency of shutdown for cleaning.

[0040] The equal-volume water distributor evenly distributes the water delivered from the water pump through the return water pipe back to the lower cooling tower packing area, forming a water utilization cycle.

[0041] The packing area features a mesh structure, and the packing material within this area is modified PVC corrugated packing. Modified PVC is resistant to acid and alkali corrosion from the spray water, and the corrugated structure extends the contact path between the air and the spray water, enhancing pre-evaporation heat dissipation. The packing is 0.4mm thick and uses modular assembly, with each piece measuring 300×300mm. This thickness and size facilitate disassembly and cleaning, and also make it easier to replace the packing compared to traditional packing stacking methods. A stainless steel support grid with a 20mm spacing is installed at the bottom of the packing to prevent collapse and deformation under long-term water immersion, ensuring unobstructed water distribution and ventilation channels.

[0042] The packing area is vertically arranged below the equal volume water distributor and above the falling film heat exchanger. It receives and cools the high-temperature water falling from the equal volume water distributor. The integrated structure falling film heat exchanger can extend the contact path between water and air, enhance the heat dissipation effect, and is vertically connected with the upper equal volume water distributor and the lower falling film heat exchanger to form a continuous heat dissipation surface.

[0043] Wherein: the film distributor 4 is detachably connected to the bottom of the packing area 3. The film distributor is horizontally arranged above the falling film heat exchanger, receiving the spray water distributed by the cooling tower seasoning, and evenly spreading the water to the outer wall of the falling film heat exchanger below.

[0044] like Figure 2 As shown, the membrane distributor 4 is a perforated plate with evenly distributed water distribution holes 41. The diameter of each hole 41 is ≥6mm, the spacing between holes is ≥30mm, and the orifice has a flared opening structure, which prevents impurities in the water from accumulating at the orifice. The surface of the membrane distributor 4 is coated with Teflon, which effectively reduces scale adhesion and minimizes scaling and clogging on the pipe walls. The vertical installation gap between the membrane distributor and the top coil of the falling film heat exchanger below is ≥10mm, and the horizontal gap between the membrane distributor and the edge of the coil is ≥5mm. This reserved vertical and horizontal installation gap allows the spray water flow to completely cover the outer wall of all heat exchange coils, eliminating localized dry areas and ensuring continuous and complete water film heat exchange. Moreover, the membrane perforated plate can be disassembled and replaced separately. It can be pulled out for cleaning by opening the inspection port of the middle heat exchanger without draining the entire circulating water or shutting down the entire unit for maintenance, making maintenance more convenient.

[0045] The upper part of the entire cooling system consists of a fan, equal volume water distributor, packing area, and film distributor, forming a wind-water distribution heat dissipation assembly. All components are arranged vertically from top to bottom.

[0046] Among them: such as Figure 3 As shown, the falling film heat exchanger 5 includes a high-temperature water inlet 51, a low-temperature water outlet 52, and falling film heat exchange coils 53. The falling film heat exchange coils 53 are multiple sets of serpentine cold water heat exchange coils horizontally stacked and integrated, with each layer consisting of a row of coils and each row of coils having an independent circuit. The multiple independent circuits allow for the shutdown of some circuits as needed, adapting to low-load winter natural cooling conditions and reducing water-side flow loss; the staggered inlet and outlet ensure that the cold water flows through the pipes in full, without air blockage.

[0047] For example: a total of 6 rows are set up, with 6 layers stacked horizontally. Each row has 12 pipes arranged in a square pattern. Every 2 rows are equipped with a set of 304 stainless steel support bars. The stainless steel support bars eliminate the vibration of the coil caused by the fan exhaust and water flow impact, and prevent fatigue leakage of the pipe welds.

[0048] The horizontal serpentine coil, parallel tube bundle, and multiple parallel loops with water distribution and collection chambers at both ends create a structure that forces water to flow inside the tubes. A gravity-fed falling film water film surrounds the tubes, positioned above the air inlet. Cold air flows upward through the coil, scouring the tube bundle and creating counter-current evaporative heat exchange with the downward-flowing spray water, fully utilizing natural air cooling. Furthermore, the high-temperature water inlet 51 is located below the low-temperature water outlet 52, ensuring a continuous water film without dry zones. The falling film heat exchanger 5 is positioned directly above the air inlet 6, with the high-temperature water inlet 51 and low-temperature water outlet 52 arranged side-by-side on the same side of the casing. The high-temperature water inlet pipe 51 is connected to the cold water supply system.

[0049] The falling film heat exchanger is vertically arranged directly below the packing area and is the core heat exchange component of the chilled water system. The central symmetrical double inspection ports allow direct contact with the coils, and the independent brackets for the single-row coils can be quickly disassembled and pulled out. Maintenance and cleaning do not require emptying the chilled water system or recovering the chilled water medium.

[0050] The air inlet 6 is located on the side wall of the shell between the fluorine-water heat exchanger and the falling film heat exchanger section. The air inlet adopts a louvered structure with a 45° inclination angle, effectively preventing rainwater and fallen leaves from flowing back into the tower and protecting the lower fluorine-water heat exchange coils. A detachable sliding rail filter is installed inside the air inlet; the filter can be directly extracted and washed from the outside of the unit, eliminating the need to enter the tower to clean dust and reducing maintenance difficulty. External cold air enters the shell through the air inlet, passing through the falling film heat exchanger and packing area from bottom to top, and then forms a counter-current heat exchange with the spray water dispersed by the distributor. The air inlet is located in the interlayer between the two heat exchangers, with the fluorine-water heat exchanger completely arranged in the water tank below the air inlet, without occupying the air-cooled ventilation channel. The fan only needs to overcome the wind resistance of the packing and falling film heat exchanger, significantly reducing fan pressure loss and annual power consumption.

[0051] The falling film heat exchanger and the air inlet form the middle part of the entire cooling system, realizing heat exchange and ventilation.

[0052] Among them: such as Figure 4 , Figure 5 As shown, the fluorine-water heat exchanger 8 includes a high-temperature refrigerant inlet 81, a low-temperature refrigerant outlet 82, and a fluorine-water heat exchange coil 83. The fluorine-water heat exchange coil 83 is a horizontally stacked, serpentine refrigerant condensing coil with multiple bare tube structures. The refrigerant condensing coil is suspended and fixedly installed in the cavity 91 of the water storage tank by a bracket, and the entire refrigerant condensing coil is immersed in water.

[0053] Specifically, the tube bundles are arranged in a dense, layered configuration, with a total of 6 rows of horizontal heat exchange coils. These coils are stacked in multiple layers, with 11 heat exchange tubes per row, arranged in a neat rectangular pattern to maximize the use of the water tank space, increase the immersion heat exchange area, and ensure sufficient heat exchange between the refrigerant and the water. The vertical spacing between the centers of adjacent coils is 25mm, and the minimum vertical clearance between the outer walls of the coils is 9mm. Fluid convection gaps are reserved between the coils and between layers, allowing the circulating water in the tank to flow freely in all directions without dead zones, avoiding localized water temperature stratification, and ensuring uniform and stable refrigerant condensation heat exchange. This spacing is optimized for fluid distribution, maximizing the arrangement of the heat exchange tube bundles and improving overall heat exchange efficiency. It also ensures consistent immersion depth throughout the coils, resulting in uniform and unbiased heat exchange. The distance between the top-layer coil and the water surface is ≥30mm; the distance between the bottom-layer coil and the bottom of the tank is ≥50mm. Zero external exposure throughout; the micro-flow of circulating water in the water tank washes the outer wall of the coil, which can effectively remove heat exchange heat, resulting in uniform water temperature. The smooth outer wall of the tube is not prone to scaling, making it suitable for long-term immersion conditions and easy to clean and maintain.

[0054] The fluorine-water heat exchanger 8 is located directly below the air inlet 6. The high-temperature refrigerant inlet 81 and the low-temperature refrigerant outlet 82 are arranged side by side on the same side of the shell. The refrigerant inlet is connected to the refrigeration compressor. The coil does not contact the bottom plate and top surface of the water tank, eliminating the suspended dry area and localized overheating. Moreover, the entire coil is a bare tube structure without fins, avoiding scale buildup, dirt accumulation, corrosion, and aging under water immersion conditions. The bare tube structure without fins makes it less prone to scale buildup and dirt accumulation during long-term underwater immersion, and cleaning only requires flushing the bottom of the water tank. The entire refrigerant-water heat exchange coil is completely submerged in the water stored in the circulating water tank at the bottom of the unit. There is no falling film and no exposed coil, which significantly reduces the fan resistance. The refrigerant flows inside the coil and is completely immersed in the micro-flowing circulating water outside the coil. The refrigerant condenses through constant temperature heat exchange in the water, resulting in stable heat exchange, resistance to high temperatures and condensation, and high heat exchange efficiency. Moreover, with the fully submerged water heat exchange method, the refrigerant condensation temperature is lower than the outdoor air wet-bulb temperature, which greatly reduces the compressor condensation pressure in summer and reduces the main unit input power.

[0055] The fluorinated water heat exchanger, along with the water tank and water pump, forms the lower part of the cooling system, completing refrigeration, heat exchange, and water storage power. The fluorinated water heat exchanger shares a spray water system with the falling film heat exchanger above it. The sunken design of the fluorinated water heat exchanger and the air inlet located between the two heat exchangers reduce resistance to airflow heat exchange and facilitate the separation, hoisting, and maintenance of the heat exchangers. Furthermore, by integrating the fluorinated water heat exchanger and water tank into one unit, the fan resistance is only that of the falling film heat exchanger and the cooling tower packing area, resulting in lower operating energy consumption.

[0056] The water storage tank 9 is a closed cavity at the bottom of the shell, used to store water and provide a water source for the spray system. It has a drain outlet at the bottom. The integrated cavity reduces weld seams between the tank and the tower, preventing leaks. The drain outlet at the bottom allows for periodic removal of sediment and scale, extending the water replacement cycle. A sight glass 7 is positioned directly opposite the water storage tank 9. This sight glass integrates water level, temperature, and turbidity monitoring modules. Located in the lower liquid level area of ​​the water storage tank, it allows real-time observation of the water level in the spray system. The sight glass provides a direct view of the water level in the lower layer of the tank, while simultaneously monitoring the water level, temperature, and turbidity.

[0057] Among them, the water pump 10 adopts a stainless steel pump body and an engineering plastic impeller, with a rated flow rate of 6m³ / h; only a single return water pipe 11 is set to connect the bottom and top equal-volume water distributor of the water storage tank, with no additional parallel branches. The stainless steel pump body is resistant to circulating water corrosion, and the plastic impeller has low operating noise; the conical water distributor has a low-pressure water distribution design, requiring only a 0.75kW small-power water pump to meet the spray flow, which is significantly more energy-efficient than traditional high-pressure spray water pumps; in addition, the single-circuit water circulation pipeline reduces the number of valves, joints, and elbows, reduces the hydraulic resistance of the pipeline, reduces leakage points, simplifies the overall automatic control logic, and is suitable for batch standardized installation in small and medium-sized computer rooms.

[0058] In addition, to enhance monitoring capabilities, a level gauge 7 is installed inside the water storage tank 9. The level gauge provides more accurate information on the water level, and the dual monitoring system prevents the failure of a single sensor.

[0059] The sight glass, level gauge, and water pump are linked. A controller is set up in the entire cooling system. The level signal output terminal of the sight glass and level gauge is connected to the signal receiving terminal of the controller, and the signal output terminal of the controller is connected to the signal receiving terminal of the water pump. The water pump volume is controlled by the level signal detected by the sight glass and level gauge. When the water level is too low, the water pump can be turned up. In addition to drawing water from the water storage tank, the water pump is also connected to an external water pipe. When the water level is too low, it means that there is not enough water in the water storage tank. At this time, an external water source is needed to provide sufficient water to the entire system. Through the regulation of the sight glass and level gauge, the water level can be accurately controlled.

[0060] In addition, for ease of maintenance, multiple maintenance ports are provided, namely the top fan maintenance port located at the top of the shell near the fan, the middle heat exchanger maintenance port located on the side of the falling film heat exchanger, and the water storage tank maintenance port located at the bottom of the shell.

[0061] Top fan access port: Located next to the top fan of the unit, it uses a hinged cover with a safety lock, which can be opened directly to inspect the fan impeller and motor.

[0062] Central heat exchanger access port: Located on the side of the falling film heat exchanger, two symmetrical access ports are provided, corresponding to the front and rear sides of the coils respectively, allowing access to the unit for cleaning the coils and film distributor. The central heat exchanger access port can be the same opening as the air inlet, directly corresponding to the coils in the falling film heat exchanger, facilitating later-stage equipment maintenance and repair of the falling film heat exchanger.

[0063] Bottom water tank access port: Located on the bottom side of the unit, it facilitates cleaning impurities from the water tank and changing the water quality.

[0064] Lifting and maintenance are achieved as follows: Four lifting lugs are installed on the top of the unit, distributed at the four corners of the unit, which can be installed by overall lifting; the maintenance ports are all located on the side of the equipment operation passage, with a maintenance space of ≥800mm. The heat exchanger coil section can be accessed through the middle maintenance port. The coil support bracket can be quickly disassembled, and a single row of coils can be pulled out and replaced individually without disassembling the entire equipment.

[0065] The operation process of this cooling system is as follows:

[0066] During operation, the water pump draws water from the storage tank and delivers it to the top, where it enters the equal-volume water distributor. After equal-volume distribution, the water flows sequentially through the packing area, the film distributor, the falling film heat exchanger, and the fluoride-water heat exchanger, finally returning to the storage tank, completing the circulation of the spray system. The fan at the top draws air upwards through the air inlet. The cool air enters from the inlet and flows upwards, creating a counter-current with the downward flow of the spray water, thus dissipating heat through evaporation. The falling film heat exchanger is connected to an external chilled water system to cool the chilled water in the tubes. The refrigerant-water heat exchanger is connected to an external refrigeration system to condense the refrigerant in the tubes. High-temperature chilled water enters the tubes of the falling film heat exchanger 5 through the high-temperature water inlet 51, is cooled by the spray water, and flows out from the low-temperature water outlet 52. The high-temperature gaseous refrigerant discharged from the refrigeration compressor enters the tubes of the refrigerant-water heat exchanger 8 through the high-temperature refrigerant inlet 81, condenses and liquefies, and flows out from the low-temperature refrigerant outlet 82, completing the synchronous cooling of the two systems. Winter mode: When the outdoor temperature is 0-15℃, the spray system is turned on, the refrigerant refrigeration system is turned off, and the water pump and fan are turned on. The falling film heat exchanger is used to provide cooling for the indoor environment, reducing the unit's operating energy consumption. In areas where the outdoor temperature may be below 0℃, the water pump is turned off, the water in the pipes is drained, and only the fan is used to achieve air convection cooling, reducing energy consumption. In addition, the falling film heat exchanger and the fluorine water heat exchanger share the same spray water and air heat dissipation system; enabling one device to simultaneously perform the dual functions of process chilled water cooling and refrigeration unit condensation. The water level in the water tank is monitored in real time by the sight glass to ensure stable water supply from the water pump; the positions of each component are corresponding vertically, the pipelines are connected, and the power is linked to form an efficient and stable composite cooling system. Specific Implementation Example 1:

[0068] This embodiment of the unit consists of two operating logics: a summer evaporation-condensation mode and a winter natural cooling energy-saving mode. The design parameters, measured data, and supporting structural design for each operating condition are as follows:

[0069] I. Basic parameters of models using this cooling system are shown in Table 1:

[0070] Equipment Name 12 HP Evaporative Cooler Unit Model HMZFL012 Fresh air supply 20000 m³ / h External pressure 160 Pa Fluorine water heat exchanger heat exchange capacity 46.6 kW Falling film heat exchanger heat exchange 35 kW water pump flow rate 6 m³ / h EC fan power 3.2 kW Water pump power 0.75 kW Compressor power 15kW Unit dimensions (length × width × height) 1400mm×1090mm×2386mm quantity 1 unit

[0071] II. Operating Temperature Design and Dual-Mode Operation Data:

[0072] 1. The design parameters and measured operating data under standard evaporative cooling mode in summer are shown in Table 2:

[0073] Circulating water inlet temperature 32℃ 32.1℃ Circulating water outlet temperature 28℃ 27.8℃ Condensation temperature 35℃ 34.7℃ Fluorine water heat exchanger heat exchange capacity 46.6 kW 45.8 kW Falling film heat exchanger heat exchange 0 kW (pipeline valves closed, not involved in heat exchange) 0 kW Total power of unit auxiliary equipment 3.2kW fan + 0.75kW water pump 3.82 kW compressor input power 15 kW 14.6 kW Total system input power 18.95 kW 18.42 kW System COP 4.2 4.31

[0074] Implementation logic of energy-saving effect during summer operation:

[0075] The controller synchronously starts the EC variable frequency fan, circulating water pump, and refrigeration compressor; the water pump delivers water from the storage tank to the conical equal-volume water distributor for even distribution, and the water flows sequentially through the packing precooling, the film forming by the film distributor, and the surface spraying of the falling film heat exchanger, before falling back to the storage tank to completely immerse the fluorinated refrigeration coil; the high-temperature refrigerant is condensed and liquefied by the circulating water in the fluorinated water heat exchanger; the central louvered air inlet introduces outdoor cold air for counter-current heat dissipation from bottom to top.

[0076] Implementation Principle: A conical equal-volume water distributor distributes water evenly at low pressure; pre-evaporation of the packing material lowers the water temperature, reducing the heat exchange load on the falling film heat exchanger; a counter-current air-water jacketed air inlet design maximizes the temperature difference between air and spray water, achieving low-temperature water output; the refrigerant coils are fully submerged in the water tank for heat exchange, ensuring the condensation temperature is lower than the ambient wet-bulb temperature, reducing the compressor load; densely arranged multi-layered tubes provide ample submersion heat exchange area, meeting the condensation and heat dissipation needs of a 15kW compressor; in summer, the computer room's cooling capacity relies entirely on the refrigeration unit, with the chilled water circuit only as a backup, allowing for the shutdown of some coil circuits to reduce water flow resistance; the submerged refrigerant coils do not obstruct the air-cooling channel, reducing fan resistance, allowing a 3.2kW fan to meet 20,000 m³ / h requirements. Air volume requirements; low condensing temperature reduces compressor pressure ratio, and the measured main unit power consumption is lower than the design value; the superposition of multiple energy-saving structures such as dual heat exchange zones, low air resistance, and low-pressure spray reduces the total power consumption of the whole unit; the layout of the sandwich air inlet and the bottom-mounted refrigerant coil eliminates the obstruction of the air-cooling channel by the refrigerant coil, and the fan does not need to overcome the air resistance of the refrigerant coil. Under the same air volume, the fan power consumption is significantly lower than that of existing integrated evaporative cooling equipment; the conical water distributor provides low-pressure water supply, and the water pump power is only 0.75kW, further reducing the power consumption of auxiliary equipment.

[0077] 2. For winter operation, the outdoor temperature needs to be above 0℃. The design parameters and measured operating data for this condition are shown in Table 3:

[0078] Process water inlet temperature 24℃ 23.9℃ Process water outlet temperature 21℃ 20.8℃ Refrigerant condensation circuit Closure and suspension of operations Closure and suspension of operations Falling film water heat exchanger heat exchange 35 kW 34.2 kW Fluorine water heat exchanger heat exchange capacity 0 kW 0 kW Auxiliary equipment operating power 0.75kW (pump operation only) 0.71 kW System Integration COP 5.1 5.24

[0079] Winter operating logic: The controller cuts off the power supply to the refrigeration compressor and stops the operation of the refrigerant system; only the 0.75kW circulating water pump is started, and the fan is completely stopped when the outdoor temperature is low; the circulating water in the storage tank is sprayed onto the outer wall of the falling film heat exchanger through the conical water distributor, and the water is cooled by natural convection of the outdoor low temperature air, and then directly supplied to the terminal of the machine room.

[0080] The layered independent loop falling film heat exchanger features a large heat exchange area, achieving chilled water cooling solely through natural air cooling. This independent heat exchange structure completely decouples the cold source system, eliminating the need for mechanical refrigeration in winter. The air-water counter-current heat exchange structure fully utilizes the outdoor low-temperature natural cold source, eliminating the need to start the compressor for refrigeration. The two heat exchangers are designed independently in separate zones, allowing for complete disconnection of the refrigerant system and eliminating ineffective heat exchange losses. Modular packing combined with a large-gap film distributor ensures a complete water film, providing sufficient evaporative heat dissipation efficiency in low-temperature environments. The fan can be completely shut down and powered off, with only the spray water circulation remaining, eliminating fan idle-load energy consumption. A single low-pressure spray pipeline requires only a small-flow water pump to maintain film distribution, eliminating continuous power consumption from the fan and significantly reducing auxiliary energy consumption compared to the synchronous operation mode of traditional units with fans and pumps. All heat exchange components are independently detachable, allowing for the shutdown of some coil circuits under low-load conditions in winter, reducing water-side flow resistance.

[0081] When the outdoor ambient temperature is <0℃, the controller shuts off the circulating water pump, opens the drain port at the bottom of the water storage tank and the low-point drain valve of the pipeline to drain all the water in the pipeline and the water tank; the two heat exchangers are arranged independently in separate zones, and there are no water blind spots inside the coils, eliminating the risk of pipeline freezing and cracking at low temperatures.

[0082] 3. A year-round comparison of the 12HP HMZFL012 unit in this embodiment with a traditional integrated evaporative chiller of the same horsepower is shown in Table 4.

[0083] Summer operation Fluorine water heat exchange, with fans and water pumps working in tandem. Single heat exchanger structure, fan and water pump operate continuously. The interlayer design with a central air inlet and a submerged refrigerant coil water tank significantly reduces fan pressure loss; condensing temperature is reduced by 3°C, and heat exchange efficiency is improved by 7%. Winter operation Only the water pump is running; the fan is shut down and power is cut off. The fan and water pump must operate synchronously. The heat exchange system is divided into independent zones, the refrigerant refrigeration circuit can be completely shut down, there is no need for the fan to operate under forced conditions, and the ineffective power consumption of the fan is eliminated. Summer system total power 18.95kW 20.1kW The conical low-pressure water distributor reduces water pump power consumption, and the low-resistance structure reduces fan power consumption, resulting in an overall energy saving rate of 5.72%. Winter auxiliary equipment power 0.75kW 3.95kW The fan can be shut down, with only the spray water pump remaining operational; the energy efficiency of auxiliary equipment is 81.01%. Water outlet temperature control range Summer 28℃, Winter 21℃ The outlet water temperature is fixed, and the adjustability is poor in low-temperature conditions. The six-layer independent loop falling film heat exchanger allows for adjustment of the heat exchange area as needed, and the conical water distributor ensures stable heat exchange under full load by distributing water evenly. Structural form Dual heat exchange chambers, each zone operates independently. A single heat exchange chamber, its function cannot be separated. With three independent access panels and a structure that allows for individual coil installation, heat exchanger disassembly eliminates the need for refrigerant recovery, significantly reducing maintenance difficulty. Maintenance losses Components can be started and stopped on demand, resulting in low wear and tear. The machine operates at full load year-round, causing it to age relatively quickly. Annual maintenance costs reduced by approximately 40%

[0084] Based on Table 4, the energy-saving benefits of this embodiment can be derived.

[0085] Summer operating benefits: The condensing temperature of this unit is 3°C lower than that of traditional units, and the compressor input power consumption is reduced by about 8%. Based on 1200 hours of operation per summer and an industrial electricity price of 0.8 yuan / kWh, the annual electricity cost savings for the compressor alone are approximately 12,000 yuan. The energy-saving effect is due to the heat exchange of the fully submerged refrigerant coil in the water tank and the low-resistance fan structure with the sandwich air intake, which doubly reduces the power consumption of the refrigeration system.

[0086] Winter operating benefits: Traditional units operate with simultaneous operation of fans and water pumps in winter, while this unit only operates with a small-power water pump, eliminating the continuous power consumption of the 3.2kW fan; based on 800 hours of operation in natural cooling mode per winter, the annual electricity cost is saved by approximately 4,000 yuan. The core of the energy saving is the layered and zoned structure where the two heat exchange systems can be independently decoupled and the fan can be stopped.

[0087] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A cooling system combining evaporation and condensation with natural cold source for an outdoor unit in a computer room, comprising a vertical tower structure shell, a variable frequency axial flow fan located at the top of the shell, a packing area, a film distributor, a falling film heat exchanger, a fluoride-water heat exchanger, a water storage tank, a water pump, and a return water pipe; characterized in that: It also includes an equal volume water distributor, and the equal volume water distributor, modular packing area, detachable membrane distributor, falling film heat exchanger and water storage tank are assembled in sequence from top to bottom inside the shell; a louvered air inlet is opened on the side wall of the shell below the falling film heat exchanger and above the water storage tank cavity, and a fluoride water heat exchanger is installed below the air inlet; The equal volume water distributor is a cone-shaped structure that is wider at the top and narrower at the bottom, and is horizontally arranged directly below the fan. The bottom of the equal volume water distributor is provided with matrix-style equidistant water distribution holes, and the water distribution holes correspond one-to-one with the packing material in the packing area below. The falling film heat exchanger is composed of multiple independent loop serpentine water coils stacked horizontally, and is equipped with high-temperature water inlets and low-temperature water outlets arranged in a staggered manner. The high-temperature water inlet is connected to the chilled water supply system of the machine room. The fluorine-water heat exchanger is composed of multiple sets of smooth tube serpentine refrigerant condenser coils stacked together and suspended and submerged in the water inside the water tank by a support; the fluorine-water heat exchanger is equipped with a high-temperature refrigerant inlet and a low-temperature refrigerant outlet arranged in parallel, and the high-temperature refrigerant inlet is connected to an external refrigeration compressor; The water storage tank is a closed cavity at the bottom of the shell. The bottom of the water storage tank is connected to the equal volume water distributor at the top through a return water pipe. The water pump is installed on the return water pipe. The shell has three independent inspection ports: the top fan inspection port, the middle side heat exchanger inspection port, and the bottom side water tank inspection port.

2. The combined evaporative condensation and natural cold source cooling system for the outdoor unit of the computer room according to claim 1, characterized in that: The inlet port of the equal volume water distributor is connected to the return water pipe, and the inlet port is equipped with a detachable filter screen; several equal volume water distribution bodies are evenly arranged on the base of the water distributor, and the water distribution holes are set at the bottom of the water distribution bodies, and the water distribution holes are chamfered at 45°; the chamfered plate is evenly distributed with funnel-shaped water distribution holes.

3. The combined evaporative condensation and natural cold source cooling system for the outdoor unit of the computer room according to claim 1, characterized in that: The packing area uses modified PVC oblique corrugated modular packing, and a stainless steel support grid is installed at the bottom of the packing.

4. The combined evaporative condensation and natural cold source cooling system for the outdoor unit of the computer room according to claim 1, characterized in that: The vertical gap between the membrane distributor and the top coil of the falling film heat exchanger below is ≥10mm, and the horizontal gap between the membrane distributor and the edge of the coil is ≥5mm; the diameter of the water distribution holes of the membrane distributor is ≥6mm and the hole spacing is ≥30mm.

5. The combined evaporative condensation and natural cold source cooling system for the outdoor unit of the computer room according to claim 1, characterized in that: The falling film heat exchanger consists of 6 layers of horizontal serpentine coils, each layer of coils being an independent heat exchange loop, with stainless steel support bars installed between every two rows of coils. The falling film heat exchanger is positioned directly above the louvered air inlet, allowing external cold air to pass through the falling film heat exchanger from bottom to top through the air inlet and form counter-current evaporative heat exchange with the sprayed water.

6. The combined evaporative condensation and natural cold source cooling system for the outdoor unit of the computer room according to claim 5, characterized in that: The louvered air inlet has a louver angle of 45°, and a sliding rail-type detachable filter is installed on the inner side of the air inlet.

7. The combined evaporative condensation and natural cold source cooling system for the outdoor unit of the computer room according to claim 1, characterized in that: The distance between the top coil of the fluorine-water heat exchanger and the water surface is ≥30mm, the distance between the bottom coil of the fluorine-water heat exchanger and the bottom of the water tank is ≥50mm, the vertical distance between the centers of two adjacent layers of coils in the fluorine-water heat exchanger is 25mm, and the net distance between the outer walls of the tubes is ≥9mm.

8. The combined evaporative condensation and natural cold source cooling system for the outdoor unit of the computer room according to claim 1, characterized in that: The water storage tank is equipped with a sight glass and a built-in level gauge. The sight glass integrates water level, water temperature, and water turbidity monitoring modules. A drain outlet is opened at the bottom of the water storage tank. The level gauge, sight glass, and water pump are linked to a controller.

9. The combined evaporative condensation and natural cold source cooling system for the outdoor unit of the computer room according to claim 1, characterized in that: The water storage tank is a closed cavity at the bottom of the shell, with a sight glass facing the water level and a level gauge inside the tank.

10. The combined evaporative condensation and natural cold source cooling system for the outdoor unit of the computer room according to claim 1, characterized in that: The top fan inspection port is equipped with a hinged safety lock cover, the middle heat exchanger inspection port is symmetrically located on both sides of the falling film heat exchanger, and the four corners of the unit are equipped with lifting lugs.

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