A finned tube heat exchanger, an air conditioning main unit and an air conditioning main unit system, and an air conditioning equipment platform

Abstract

This invention belongs to the fields of high-efficiency energy-saving air conditioning technology and green building, and discloses a finned tube heat exchanger, its air conditioning unit and system, and an air conditioning equipment platform. The finned tube heat exchanger has a U-shaped horizontal cross-section, with the two sides of the U being the long sides and the bottom side being the short side; the length ratio of the long side to the short side is 2-6:1. The air conditioning unit includes a finned tube heat exchanger, a compressor, a gas-liquid separator, and a fan, etc.; the air conditioning unit has an outer frame. The air conditioning system includes at least two air conditioning units arranged side-by-side, with an outward-opening V-shaped air duct formed between the finned tube heat exchangers of adjacent air conditioning units. The air conditioning equipment platform includes equipment space for setting up the air conditioning system and the air conditioning system itself. This invention constructs a flexible and efficient heat exchange airflow structure for the air conditioning unit; facilitates the inspection and maintenance of the air conditioning unit; and creates conditions for constructing a side-inlet, side-outlet airflow structure to match the exterior facade of the equipment platform.

Description

Technical Field

[0001] This invention belongs to the fields of high-efficiency energy-saving air conditioning technology and green building, and more specifically, relates to a finned tube heat exchanger and its air conditioning unit and air conditioning unit system, and air conditioning equipment platform. Background Technology

[0002] Finned tube heat exchangers are mainly composed of multiple rows of fins and multiple rows of copper tubes passing through the fins. The inside of the copper tubes is the refrigerant side, and the space between the fins outside the copper tubes is the air side. Air passes through the outside of the finned tube heat exchanger, thereby exchanging heat with the refrigerant side.

[0003] (This prior art solution appears to describe a detachable plate heat exchanger rather than a finned tube heat exchanger.) The prior art finned tube heat exchanger CN212158280U discloses a finned tube heat exchanger comprising multiple heat exchange tubes and multiple fins. Each fin has multiple tube holes, and the multiple fins are spaced apart along the thickness direction of the fin. Multiple heat exchange tubes are respectively inserted into the multiple tube holes of each fin. The longitudinal spacing of adjacent heat exchange tubes on the fin is St, and the spacing of adjacent fins in the thickness direction of the fin is Fp, where 16 mm ≤ St ≤ 18 mm, and 1.1 mm ≤ Fp < 1.3 mm. This patent increases the width of the fins, thereby increasing the number of bridging slots on the fins. In addition to increasing the heat transfer area, it also enhances the turbulence of the air by the fins, improving the convective heat transfer intensity. This patent achieves a compact structure and improved heat exchange performance for finned tube heat exchangers by limiting the longitudinal spacing of the centers of adjacent heat exchange tubes to between 16 mm (inclusive) and 18 mm (inclusive), and the spacing of adjacent fins in the thickness direction to between 1.1 mm (inclusive) and 1.3 mm (exclusive). However, this solution fails to effectively increase the fin heat exchange area S, reduce the heat transfer temperature difference Δt within the heat exchanger body, increase the evaporation pressure, and reduce the condensation pressure.

[0004] The existing finned tube heat exchangers, air conditioning units, and the structural relationship between the air conditioning units and the external corridor equipment platform still have many technical problems, including:

[0005] 1) Finned tube heat exchangers have small ventilation surfaces and small fin heat exchange areas, resulting in poor heat exchange performance.

[0006] 2) The energy density of the air conditioning unit platform is low.

[0007] The power density of current air conditioning main units, calculated based on their floor area, generally exceeds 40 kW / ㎡, while the power density of the current air conditioning main unit equipment platform is generally only about 11.6 kW / ㎡. This means that the floor area occupied by the air conditioning main unit's air inlet and outlet ducts, maintenance passages, and ventilation blind spots on the platform is more than 2.4 times the floor area of ​​the air conditioning main unit itself. The current air conditioning main unit equipment platform occupies too much floor area, generally exceeding 1.5% of the total building area, which has become a prominent problem in building HVAC design.

[0008] 3) The equipment platform occupies too much horizontal width of the building facade.

[0009] The current air conditioning unit and equipment platform have an unreasonable air intake and exhaust structure, low utilization of depth and top space, and excessive occupation of the building facade's horizontal width by the equipment platform. In existing high-rise buildings, equipment floors are set approximately every 12 floors, with the surrounding corridors entirely occupied by the air conditioning unit's air intake and exhaust vents. Figure 4 As shown, the width of a building facade is the second most important resource in a building's performance index, after the building area. In high-rise and super high-rise buildings, the air conditioning unit platforms compete for the width of the building facade, occupying too much of the horizontal width. This obstructs the visual communication between the interior space of the same floor and the external environment, and has become a prominent problem in building HVAC design. Summary of the Invention

[0010] To address the aforementioned problems in the prior art, this invention innovates the structure of the external heat exchanger module of the central air conditioning unit and the spatial structural relationship between the central air conditioning unit and the building, providing a finned tube heat exchanger.

[0011] Another object of the present invention is to provide an air conditioning unit and an air conditioning unit system thereof;

[0012] Another objective of this invention is to provide an air conditioning unit equipment platform.

[0013] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0014] A finned tube heat exchanger, wherein the horizontal cross-section of the finned tube heat exchanger is U-shaped, the two sides of the U-shaped finned tube heat exchanger are long sides, and the bottom side is a short side; the length ratio of the long side to the short side is 2 to 6:1.

[0015] Furthermore, the fins are arranged vertically and horizontally; the length ratio of the long side to the short side is 3 to 4:1.

[0016] Furthermore, one side of the cross-section of the finned tube heat exchanger perpendicular to the long side of the fins is the air inlet side of the heat exchanger, and the other side is the air outlet side of the heat exchanger; the air outlet side belongs to the negative pressure chamber area of ​​the heat exchanger.

[0017] The air inlet surface is a finned tube heat exchanger, and the angle between the air inlet and the tip of each finned tube heat exchanger is an obtuse angle; the obtuse angle β is 97.5°~135°.

[0018] The incoming airflow strikes the tip of each fin in the finned tube heat exchanger at an obtuse angle β, and is reflected by the fin tip into the fin gap and flows into the negative pressure chamber of the heat exchanger.

[0019] Furthermore, the airflow rate entering each fin gap d is equal to the airflow intercepted by the vertical distance δ between the tips of the two finned plates at the front and rear of the finned tube heat exchanger on the air inlet section.

[0020] δ=d·sinα / 2, where α is the apex angle α of the extension line of the long side of the heat exchanger;

[0021] Preferably, the apex angle α of the extended long side of the heat exchanger is 15° to 110°.

[0022] More preferably, the apex angle α of the extended long side of the heat exchanger is 30° to 90°.

[0023] More preferably, the apex angle α of the extended long side of the heat exchanger is 30° to 60°.

[0024] The vertical distance δ between the tips of the front and rear finned tube heat exchangers on the air inlet section is between 0.13d and 0.7d; preferably, the airflow velocity between the fins is 1 / 3 of the air inlet velocity, and the apex angle α corresponding to the extension line of the long side of the heat exchanger is 39° and the obtuse angle β is 109.5°.

[0025] An air conditioning unit, wherein the finned tube heat exchanger, an air conditioning compressor, a gas-liquid separator, a four-way valve, an expansion valve, an electrical box, and a fan are disposed within the housing of the air conditioning unit;

[0026] The finned tube heat exchanger and at least part of the shell together form a negative pressure chamber that connects to the heat exchange air path of the finned tube heat exchanger.

[0027] Furthermore, at least two fans are installed above the finned tube heat exchanger along its long side.

[0028] Furthermore, the fan is an axial flow fan or a centrifugal fan; preferably, the fan is a backward-curved external rotor centrifugal fan.

[0029] Furthermore, the air conditioning compressor, gas-liquid separator, four-way valve, expansion valve, and electrical box are located in the lower-middle ventilation blind zone of the negative pressure chamber of the finned tube heat exchanger, near the back panel of the air conditioning unit.

[0030] An air conditioning unit system includes at least two air conditioning units arranged side by side, with an outward-facing V-shaped air duct formed between the finned tube heat exchangers of adjacent air conditioning units, the opening of the V-shaped air duct facing the opposite direction to the opening of the U-shaped finned tube heat exchanger.

[0031] Furthermore, the distance d between adjacent air conditioning units is 3 to 20 cm.

[0032] Furthermore, the included angle γ of the V-shaped air duct is 50° to 120°.

[0033] An air conditioning unit platform is provided, wherein at least one set of air conditioning unit systems is arranged horizontally within the platform; the platform has an exterior facade for ventilation, and the bottom edge of the U-shaped finned tube heat exchanger of the air conditioning unit system is close to the exterior facade; an exhaust cavity is provided above the air conditioning unit, and the exhaust port of the exhaust cavity is located and / or close to the exterior facade.

[0034] Furthermore, an exhaust area and an air inlet area are provided on the facade; the exhaust area on the facade corresponds to the exhaust cavity of the air conditioning unit, and the air inlet area on the facade corresponds to the air inlet of the air conditioning unit.

[0035] Furthermore, the exhaust areas on the facade are continuously arranged in the upper part of the facade, and the air inlet areas on the facade are continuously arranged in the middle and lower parts of the facade. The boundary between the exhaust areas and the air inlet areas of the facade is a horizontal straight line or the boundary line is close to a horizontal straight line.

[0036] Furthermore, the area of ​​the exhaust zone on the facade is 25% to 50% of the facade area used for ventilation.

[0037] Furthermore, the back panel of the air conditioning unit and the inner wall of the equipment platform form a three-in-one passage for pedestrians, maintenance, and installation of copper pipes and cable trays for the air conditioning system.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] ① Construct a high-efficiency heat exchange air path structure for the external heat exchanger of the air conditioning unit to improve the unit's energy density.

[0040] In this embodiment, the air conditioning unit adopts an aerodynamic layout with medium-speed air intake on the lower middle part of the short side and high-speed air exhaust at the top, incorporating the main sections of the air intake and exhaust channels of the external heat exchanger into the air conditioning unit.

[0041] This invention achieves a large-area heat exchanger ventilation surface by unfolding along the air inlet surface of the deep U-shaped finned tube heat exchanger within the limited space of the air conditioning unit, and then further unfolding on the large-area heat exchanger ventilation surface to obtain a huge-area finned heat transfer surface.

[0042] In this invention, the external airflow enters the air conditioning unit at a medium speed of about 4 m / s. Inside the air conditioning unit, the incoming airflow is incident on the rear fins of the fin gap at an obtuse angle. The incoming airflow, which is cut off by the rear fin planer, enters the fin gap, decelerates and disperses, and passes through the deep U-shaped finned tube heat exchanger, which has a large total ventilation cross-section and a huge total heat exchange area S, at a low speed of about 1.6 m / s for heat exchange. After heat exchange, it flows into the negative pressure chamber and converges towards the fan intake under the negative pressure traction of the external heat exchanger fan. After being accelerated and pressurized by the fan, it is finally discharged from the exhaust chamber at a high speed of about 8 m / s.

[0043] The air conditioning unit of this invention features a large external heat exchanger ventilation surface, which in turn expands a massive fin heat exchange area S on the large ventilation surface. This reduces the heat transfer temperature difference Δt of the heat exchanger body, lowers the condensing pressure and increases the evaporating pressure, increases the refrigerant circulation, evaporator heat absorption, and condenser heat release, while also effectively controlling the unit's volume and increasing the unit's energy density. This provides the prerequisite for improving the energy density of the equipment platform.

[0044] ② Facilitate air conditioner unit inspection and repair

[0045] This invention centrally positions all refrigerant circuit components, such as the compressor, gas-liquid separator, four-way valve, expansion valve, and electrical box, in the ventilation blind zone of the lower middle part of the negative pressure chamber of the heat exchanger, close to the back plate. The back plate of the negative pressure chamber is located on the short side of the main unit, and when the air conditioning main unit is installed on the equipment platform, the back plate of the negative pressure chamber of the external heat exchanger faces the maintenance passage on the inside of the platform.

[0046] The components that may malfunction in an air conditioning unit are usually moving parts of the refrigerant circuit, such as the compressor, four-way valve, expansion valve, and electrical box, as well as circuit components such as contactors, controllers, sensors, and fans. The structural design of the air conditioning unit in this embodiment facilitates inspection and maintenance: when a malfunction occurs, the back panel of the negative pressure chamber of the external heat exchanger can be opened through the maintenance channel on the inside of the platform. The refrigerant circuit components that may malfunction, such as the compressor, four-way valve, expansion valve, electrical box, and fan, are clearly visible, making inspection and maintenance very convenient and solving the inherent inspection and maintenance problems of air conditioning units.

[0047] ③ This created conditions for constructing a side-inlet, side-outlet airflow structure to complement the exterior facade of the equipment platform.

[0048] The classic top-discharge central air conditioning unit is tailor-made for rooftop terrace scenarios; moving the equipment from the rooftop terrace to the middle floor of the building requires an innovative combination of the air duct of the top-discharge air conditioning unit and the exterior facade of the platform.

[0049] This invention establishes an aerodynamic layout of "medium-speed air intake in the lower part of the main unit, high-speed air exhaust in the top exhaust cavity, with the air inlet and exhaust outlets set in the same direction and on the same side, and the ratio of air intake area to exhaust area ≈ 2:1". An "exhaust cavity" with an exhaust cross-sectional area of ​​approximately 1 / 2 of the air intake surface is set at the top of the negative pressure cavity of the external heat exchanger set along the long side, thus utilizing the unused space at the top of the equipment platform. This embodiment is not only compact in structure, but also has air inlet and exhaust outlets of the air conditioning main unit set in the same direction, on the same side, and vertically, which prepares the conditions for installation on the equipment platform adjacent to the exterior facade and for constructing a smooth airflow structure with the air conditioning main unit's side intake and side exhaust in coordination with the equipment platform's exterior facade.

[0050] In this embodiment, under the design concept of air inlet area: exhaust area ≈ 2:1, the exhaust speed reaches twice the inlet speed and the exhaust dynamic pressure head reaches four times the inlet dynamic pressure head. This effectively improves the exhaust speed and kinetic energy of the air conditioner's external heat exchanger, and effectively improves the range and diffusion dilution effect of the air conditioner's exhaust jet penetrating the outer facade of the equipment platform and entering the ambient atmosphere.

[0051] ④ Reduce the horizontal width of the equipment floor facade occupied by the air inlet and outlet surfaces of the air conditioning unit.

[0052] The width of a building facade is a crucial resource in the building index system, second only to the building area. Currently, the air conditioning unit's air inlet and outlet surfaces occupy too much of the horizontal width of the building's equipment floor facade, which obstructs ventilation, lighting, and visual communication between the interior space and the external environment on the same floor. This has become a prominent problem in building HVAC design.

[0053] This embodiment improves the power density of the air conditioning unit by reorganizing the internal external heat exchanger and the air inlet and outlet paths of the external heat exchanger. As a result, it significantly reduces the floor space occupied by the equipment platform under the same building heat load conditions, and significantly reduces the horizontal width of the building equipment floor facade occupied by the air inlet and outlet surfaces of the air conditioning unit, thus ensuring ventilation, lighting and visual communication between the internal space of the same floor and the external environment. Attached Figure Description

[0054] Figure 1 A three-dimensional structural diagram of a deep U-shaped finned tube heat exchanger;

[0055] Figure 2 A horizontal cross-sectional view of the air conditioner unit during operation, showing how the "fin planer" at the fin gap inlet intercepts the incoming airflow, performs a stepped planing to slow it down, and then flows into the fin gap to complete heat exchange with the fins before being discharged from the fin gap.

[0056] Figure 3 A three-dimensional view of an air conditioning unit using a deep U-shaped finned tube heat exchanger;

[0057] Figure 4 This is a vertical sectional view of the negative pressure chamber structure of an air conditioning unit using a deep U-shaped finned tube heat exchanger.

[0058] Figure 5 This is a top view of the negative pressure chamber structure of an air conditioning unit using a deep U-shaped finned tube heat exchanger;

[0059] Figure 6 Schematic diagram of an air conditioning system using a deep U-shaped finned tube heat exchanger main unit;

[0060] Figure 7 A vertical sectional view of an air conditioning unit using a deep U-shaped finned tube heat exchanger during operation;

[0061] Figure 8 A top view of an air conditioning unit using a deep U-shaped finned tube heat exchanger in operation;

[0062] Figure 9 This is a structural diagram of the air conditioning unit system;

[0063] Figure 10 This is a vertical sectional view of the air conditioning unit structure of the deep U-shaped finned tube heat exchanger using a backward-inclined external rotor centrifugal fan in Example 2.

[0064] Figure 11 This is a vertical sectional view of the air conditioning unit of the deep U-shaped finned tube heat exchanger using a backward-inclined external rotor centrifugal fan in Example 2.

[0065] Figure 12 A vertical sectional view of the air conditioning unit platform operating with a deep U-shaped finned tube heat exchanger;

[0066] Figure 13 This is a top view of a heavy-duty equipment platform for an air conditioning unit that uses a deep U-shaped finned tube heat exchanger.

[0067] Figure 14 Top view of a heavy-duty equipment platform operating with an air conditioning unit using a deep U-shaped finned tube heat exchanger;

[0068] Figure 15 This is a schematic diagram showing the relationship between the air intake area and the air exhaust area on the exterior facade. Detailed Implementation

[0069] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the described embodiments without creative effort are within the scope of protection of this application.

[0070] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0071] In the description of this invention, it should be understood that the terms "lateral", "longitudinal", "length", "up", "down", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0072] Definition: An external corridor-type equipment room platform, defined as the direction perpendicular to the external facade of the external corridor-type equipment platform as longitudinal, and the direction parallel to the external facade of the external corridor-type equipment platform as transverse.

[0073] Example 1

[0074] like Figure 1-2 As shown, a finned tube heat exchanger has an air inlet surface that expands to obtain a large area of ​​heat exchanger ventilation surface. The air inlet surface is then expanded again to obtain a huge area of ​​finned heat transfer surface, thereby effectively increasing the finned heat transfer area S, reducing the heat transfer temperature difference Δt of the heat exchanger body, increasing the evaporation pressure, and reducing the condensation pressure.

[0075] A finned tube heat exchanger, wherein the horizontal cross-section of the finned tube heat exchanger 37 is U-shaped, with the two sides of the U-shape being long sides 155 and the bottom side being a short side 156; the length ratio of the long side 155 to the short side 156 is 2 to 6:1.

[0076] The finned plate 110 is vertically arranged and arranged along the horizontal direction.

[0077] The finned tube heat exchanger 37 is equipped with a refrigerant path 134 and a lotus-shaped gas collection pipe 133.

[0078] The finned tube heat exchanger includes finned plates 110 and heat exchange tubes 115; multiple parallel finned plates 110 with a certain distance between them form a fin group; and the heat exchange tubes 115 pass through the finned plates 110 in a direction perpendicular to the plane of the finned plates 110.

[0079] In one specific implementation, the length ratio of the long side 155 to the short side 156 is 3 to 4:1.

[0080] The finned tube heat exchanger 37 has an air inlet side on one side of the cross section perpendicular to the long side of the fins, and an air outlet side on the other side; the air outlet side belongs to the negative pressure chamber 124 area of ​​the heat exchanger.

[0081] The air inlet surface is a finned tube heat exchanger, and the angle between the air inlet and the tip of each finned plate 110 on the finned tube heat exchanger 37 is an obtuse angle β; the obtuse angle β is 97.5°~135°;

[0082] The incoming airflow impacts the tip of each fin plate 110 in the finned tube heat exchanger 37 at an obtuse angle β, and is reflected by the fin tip plate 110 into the fin gap and flows into the negative pressure chamber 124 of the heat exchanger.

[0083] The airflow rate entering each fin gap d is equal to the airflow intercepted by the vertical distance δ between the tips of the two finned plates 110 at the front and rear of the finned tube heat exchanger on the air inlet section.

[0084] δ=d·sinα / 2, where α is the apex angle α of the extension line of the long side of the heat exchanger;

[0085] As an optional implementation, the apex angle α of the extended long side of the heat exchanger is 15° to 110°.

[0086] As an optional implementation, the apex angle α of the extended long side of the heat exchanger is 30° to 90°.

[0087] As an optional implementation, the apex angle α of the extended long side of the heat exchanger is 30° to 60°.

[0088] The vertical distance δ between the tips of the front and rear finned plates 110 of the finned tube heat exchanger 37 on the air inlet section is between 0.13d and 0.7d.

[0089] In one specific implementation, the airflow velocity between the fins is 1 / 3 of the inlet velocity, and the apex angle α corresponding to the extension line of the long side of the heat exchanger is 39° and the obtuse angle of incidence β is 109.5°.

[0090] The finned tube heat exchanger 37 has a deep U-shaped horizontal cross section, with the two sides of the U-shape being longitudinal and the bottom side being transverse.

[0091] In this embodiment, the microscopic process of airflow entering and exiting the fin plate gap and flowing at low speed in the fin plate gap is the central link.

[0092] At the airflow inlet section EE, the medium-speed airflow of about 4 m / s, flowing in from the outer facade of the equipment platform, is propelled in a uniform laminar flow to the fin gap inlet section FF. At FF, the airflow line forms an obtuse angle β with the fin behind the gap. The fin behind the gap acts as a "planer," "planing" a piece of airflow from the main airflow and inserting it into the fin gap. At FF, the main airflow "planed" out by the tip of the "fin planer" is intercepted and impacts the tip of the "planer" on the fin behind the gap at an obtuse angle β. After being reflected by the fin in front of the gap, it diffuses and decelerates in the fin gap. The airflow of about 1.5 m / s, which has been decelerated by the collision and diffusion, is pulled by the negative pressure of the negative pressure chamber and overcomes the resistance of the fin gap channel to flow out of the fin channel. The low-speed airflow that reaches the fin gap outlet section GG is accelerated again to a medium-speed airflow of about 4 m / s under the negative pressure of the negative pressure chamber and converges and is discharged at the HH section.

[0093] Example 2

[0094] like Figure 3-8 As shown, an air conditioning unit is provided with a finned tube heat exchanger 37 as described in Embodiment 1, as well as an air conditioning compressor 121, a gas-liquid separator 126, a four-way valve, an expansion valve, an electrical box, and a fan 38, etc.

[0095] The finned tube heat exchanger 37, together with part of the shell, forms a negative pressure chamber 124 that connects to the heat exchange air path of the finned tube heat exchanger.

[0096] Specifically, the bottom plate, side plate, back plate 39, top plate and finned tube heat exchanger 37 of the shell are combined to form the negative pressure chamber 124 of the heat exchanger.

[0097] At least three fans 38 are installed above the finned tube heat exchanger 37 along the long side.

[0098] Fan 38 is an axial flow fan.

[0099] The air outlet of the negative pressure chamber 124 of the heat exchanger is provided with an exhaust chamber 33, and the exhaust port 331 of the exhaust chamber 33 is located on the same side as the air inlet 125 of the shell.

[0100] The exhaust port 331 of the exhaust cavity 33 faces the short side of the air conditioner unit housing.

[0101] The area below the air outlet of the negative pressure chamber 124 of the heat exchanger, adjacent to the back plate, is a ventilation blind zone; the refrigerant circuit components, including the air conditioning compressor 121, gas-liquid separator 126, four-way valve, expansion valve, electrical box, etc., are located in the ventilation blind zone inside the negative pressure chamber 124 of the heat exchanger.

[0102] like Figure 9As shown, an air conditioning unit system includes at least two air conditioning units arranged side by side. A V-shaped air duct 157 with an outward opening is formed between the finned tube heat exchangers 37 of adjacent air conditioning units. The opening of the V-shaped air duct 157 faces the opposite direction to the opening of the U-shaped finned tube heat exchanger 37.

[0103] The distance d between adjacent air conditioning units is 3 to 20 cm.

[0104] The included angle γ of the V-shaped air duct 157 is 50° to 120°.

[0105] The air conditioning unit in this embodiment embodies the concept of a building distributed energy system where the air conditioning unit is removed from the building roof and moved into the ordinary floors. It is designed for application scenarios with an open-sided corridor-style equipment platform on the ordinary floors. With the goal of maximizing the air intake and exhaust potential and ventilation and heat exchange potential of the equipment platform's exterior facade, the structure of the air conditioning unit is innovatively designed.

[0106] ①Use deep U-shaped finned tube heat exchangers

[0107] The air conditioning unit adopts a finned tube heat exchanger with a deep U-shaped horizontal cross section. The two sides of the U-shaped finned tube heat exchanger are the long sides, which are longitudinal, and the bottom side is the short side, which is transverse. Fans are installed along the longitudinal long side of the U-shape, and at least two fans are installed.

[0108] On the equipment platform, the short side of the air conditioning unit is set parallel to the facade, achieving the goal of "occupying less facade space and exploring the depth of the equipment platform".

[0109] This embodiment starts from the heat exchange capacity Q = K × S × Δt of the external heat exchanger. Within the limited space of the air conditioning unit, a deep U-shaped finned tube heat exchanger is arranged vertically. The heat exchanger ventilation surface is obtained by spreading it along the air inlet surface of the deep U-shaped finned tube heat exchanger. The finned tube heat exchanger is then spread out again on the large area of ​​the heat exchanger ventilation surface to obtain a huge area of ​​finned heat transfer surface. This effectively expands the finned heat transfer area S of the external heat exchanger of the air conditioning unit, reduces the heat transfer temperature difference Δt of the heat exchanger body, increases the evaporation pressure and reduces the condensation pressure.

[0110] ② Use a "fin planer" to plan the intake airflow.

[0111] The rear panel of the air conditioning unit has a lateral width greater than the width of the front edge (bottom edge) of the U-shaped finned tube heat exchanger. The side of the U-shaped finned tube heat exchanger forms an acute angle with the longitudinal airflow line. The fins of the side finned tube heat exchanger act as "fin planers," evenly "planing" the finned airflow from the airflow entering the air conditioning unit and allowing it to flow into the fin gaps. On the equipment platform, an outward-opening V-shaped air duct is formed between adjacent units. The V-shaped air duct and the opening of the U-shaped finned tube heat exchanger face opposite directions, creating a complementary reverse design. The fin planers on two adjacent U-shaped finned tube heat exchangers better distribute the airflow entering from the external facade.

[0112] ③ Innovative design of refrigeration circuit

[0113] In this embodiment, the refrigeration circuit components such as the compressor, four-way valve, expansion valve, and gas-liquid separator are innovatively placed in the lower middle part of the negative pressure chamber of the deep U-shaped finned tube heat exchanger, close to the back plate of the negative pressure chamber. This area is exactly the ventilation blind zone of the negative pressure chamber of the external heat exchanger.

[0114] These components, along with the external heat exchanger, refrigerant connecting pipes, indoor unit heat exchanger, and other assemblies, form a refrigeration and air conditioning cycle loop in the order of compressor-four-way valve-condenser-expansion valve-evaporator-four-way valve-gas-liquid separator-compressor. The compressor, as the power source of the refrigeration cycle loop, establishes high and low pressure states for the refrigerant in the condenser and evaporator pipes, driving the refrigerant to circulate and undergo repeated phase changes in the refrigeration cycle loop to achieve "heat transfer." Specifically, the refrigerant liquid absorbs heat through evaporation in the evaporator pipes and then absorbs heat from the low-temperature ambient air flowing between the fins through the large heat absorption area S of the copper pipes. The high-temperature, high-pressure refrigerant gas releases heat through condensation in the condenser pipes and then releases heat to the high-temperature ambient air flowing between the fins through the large heat release area S of the copper pipes. This achieves the migration of heat from the low-temperature environment where the air conditioner evaporator is located to the high-temperature environment where the condenser is located.

[0115] This embodiment uses an air conditioning unit with a deep U-shaped finned tube heat exchanger and an exhaust chamber;

[0116] In this embodiment, when the air conditioning unit system is running, the fan in the negative pressure chamber of the deep U-shaped finned tube heat exchanger draws air from the chamber connected to its air intake, creating negative pressure within the chamber. This negative pressure draws ambient air from outside the external heat exchanger into the air conditioning unit at a medium speed of approximately 4 m / s. After entering the air conditioning unit, the air disperses and slows down, flowing towards the deep U-shaped finned tube heat exchanger, which has a large ventilation cross-section and a large total fin area. It then flows through the fin gaps of the deep U-shaped finned tube heat exchanger at a low speed and low resistance of less than 1.6 m / s, achieving heat exchange between the ambient air and the refrigerant inside the copper tubes of the external heat exchanger. After heat exchange, the ambient air enters the negative pressure chamber, then converges and accelerates, flowing into the fan intake with the lowest pressure. It is then pressurized by the fan and discharged outwards at a high speed of over 8 m / s through the exhaust chamber.

[0117] Example 3

[0118] like Figure 10-11 As shown, this embodiment discloses an air conditioning unit. The difference between this embodiment and embodiment 2 is that the fan adopts a backward-inclined external rotor centrifugal fan.

[0119] This embodiment has all the advantages of embodiment 2, and due to the use of a backward-inclined external rotor centrifugal fan, the airflow is more powerful and the ventilation efficiency is higher; by vertically staggering the backward-inclined external rotor centrifugal fan, the number of centrifugal fans can be arranged according to the total width of the air inlet of multiple centrifugal fans being equal to the longitudinal length of the external heat exchanger, and multiple fans can be set to meet the air volume requirements.

[0120] In the specific implementation of this embodiment, both this embodiment and Embodiment 2 are innovative air conditioning units with external heat exchanger air paths. Both adopt an aerodynamic layout of medium-speed air intake on the lower middle part of the short side and high-speed air exhaust at the top, incorporating the main sections of the external heat exchanger's air intake and exhaust channels inside the air conditioning unit. Both utilize the limited space of the air conditioning unit to obtain a large area of ​​heat exchanger ventilation surface by extending along the air intake surface of the deep U-shaped finned tube heat exchanger, and then further extending on this large area to obtain a huge area of ​​finned heat transfer surface. Both involve external airflow from the air conditioning unit... The airflow enters the air conditioning unit at a medium speed of about 4 m / s. Inside the unit, the airflow enters the rear fins of the fin gap at an obtuse angle. The airflow that is cut off by the rear fin planer enters the fin gap, slows down and disperses, and passes through the deep U-shaped finned tube heat exchanger, which has a large total ventilation cross-section and a huge total heat exchange area S, at a low speed of about 1.6 m / s for heat exchange. After heat exchange, it flows into the negative pressure chamber and converges towards the fan intake under the negative pressure of the external heat exchanger fan. After being accelerated and pressurized by the fan, it is finally discharged from the exhaust chamber at a high speed of about 8 m / s.

[0121] Example 4

[0122] like Figure 12-15 As shown, an air conditioning unit equipment platform is provided, and a row of air conditioning unit systems of embodiment 2 or 3 are arranged horizontally within the equipment platform.

[0123] This embodiment employs a heavy-duty equipment platform with horizontally grouped heavy-duty air conditioning units using deep U-shaped finned tube heat exchangers. The exterior facade of the equipment platform is a crucial resource, as important as the platform's surface area. Enhancing the air intake velocity in the air inlet area to a medium speed (above 4 m / s) and controlling the exhaust velocity in the exhaust area to a moderately high speed (not exceeding 12 m / s) are prerequisites for the platform to achieve "heavy load" operation. The positional relationship, area ratio, and energy intensity relationship between the air intake and exhaust areas on the facade are reorganized. Furthermore, the heavy-duty air conditioning units described in embodiments 2 / 3 are used to construct a high-strength, high-efficiency air intake and exhaust facade for the equipment platform, significantly increasing its power density.

[0124] The equipment platform has an exterior facade 1 for ventilation. The bottom edge (i.e., the short side 156) of the U-shaped finned tube heat exchanger 37 of the air conditioning unit system is close to the exterior facade 1. An exhaust chamber 33 is provided above the air conditioning unit, and the exhaust port 331 of the exhaust chamber 33 is close to the exterior facade 1.

[0125] The exterior facade 1 has an exhaust area 132 and an air intake area 34; the exhaust area 132 on the exterior facade 1 corresponds to the air conditioner unit exhaust port 331, and the air intake area 34 on the exterior facade 1 corresponds to the air conditioner unit air intake port 125.

[0126] The exhaust zones 132 on the exterior facade are continuously arranged on the upper part of the facade, and the air intake zones 34 on the exterior facade are continuously arranged on the middle and lower parts of the facade. The boundary between the exhaust zones and the air intake zones of the exterior facade 1 is a horizontal straight line or a boundary line that is close to a horizontal straight line.

[0127] The area of ​​the exhaust zone 132 on facade 1 is 25% to 50% of the facade area used for ventilation. Facades used for ventilation refer to facades where airflow enters and exits.

[0128] The back panel 39 of the air conditioning unit and the inner wall 2 of the equipment platform form a three-in-one passage 51 for pedestrians, maintenance, and installation of air conditioning system copper pipes and cable trays.

[0129] The refrigerant connection pipe 81 or the chilled water connection pipe is installed on the cable tray 8. The air conditioning unit is connected to the indoor air conditioning units or fan coil units of each floor and area of ​​the building through the refrigerant connection pipe 81 or the chilled water connection pipe. The air conditioning unit module works together with the indoor units / fan coil units to cool (heat) the indoor space of the building.

[0130] In this embodiment, the air conditioning unit and the indoor heat exchanger 127 are connected to form an air conditioning system.

[0131] This embodiment uses an equipment platform, with the vertical facade as the longitudinal direction and the parallel facade as the transverse direction;

[0132] This embodiment adopts a dense arrangement of heavy-duty air conditioning units along the horizontal direction of the equipment platform, and centralizes the exhaust vents of multiple air conditioning units that are isolated on the traditional equipment platform, effectively integrating the resources of the air intake and exhaust areas on the exterior facade, and effectively reducing the boundary length between the exhaust area and the air intake area.

[0133] In this embodiment, on the equipment platform, an outward-facing V-shaped air duct is formed between adjacent main units. The V-shaped air duct and the opening of the U-shaped finned tube heat exchanger face opposite directions, forming a reverse complementary design. The fin planers on the two adjacent U-shaped finned tube heat exchangers better distribute the incoming airflow from the outer facade of the equipment platform.

[0134] In this embodiment, a high-speed exhaust zone is set at the top of the equipment platform's exterior facade, and a large-area medium-speed air intake zone is set in the middle and lower part. The air intake zone and exhaust zone are designed to complement each other, with the area outside the exhaust zone being the air intake zone, thereby expanding the cross-sectional area of ​​the air intake zone and constructing a low-resistance, high-efficiency air intake and exhaust facade for the equipment platform.

[0135] In this embodiment, when the heavy-duty equipment platform with horizontally grouped heavy-duty air conditioning units using deep U-shaped finned tube heat exchangers is in operation, the fans in the negative pressure chambers of the external heat exchangers of each air conditioning unit operate, drawing out the air from the negative pressure chambers of their respective connected deep U-shaped finned tube heat exchangers. This creates negative pressure within the negative pressure chambers, drawing ambient air through the outer facade of the equipment platform into the interior of the air conditioning units. After the ambient air enters the air conditioning units, the incoming airflow enters the rear fins of the fin gap at an obtuse angle β. The incoming airflow, which is then cut off by the rear fin planer blades, enters the air conditioning unit... The air enters the gap between the fins, decelerates and disperses, and passes at low speed through the deep U-shaped finned tube heat exchanger, which features a large total ventilation cross-section and a huge total heat exchange area. After heat exchange, the ambient air flows into the negative pressure chamber and, under the negative pressure traction of the external heat exchanger fan, converges towards the fan intake. It is then pressurized by the fan and passes through the exhaust chamber, passing through the top of the equipment platform's exterior facade, and is injected into the ambient atmosphere at high speed for diffusion and dilution. In this embodiment, the exhaust velocity is ≥ 2 times the intake velocity, and the exhaust airflow, with more than 4 times the kinetic energy of the intake airflow, is injected into the atmospheric environment in the form of a jet, resulting in good diffusion and dilution effects.

[0136] The advantages of this embodiment, which uses a heavy-duty equipment platform with horizontally grouped heavy-duty air conditioning units and deep U-shaped finned tube heat exchangers, include:

[0137] ① Construct a low-resistance, high-efficiency air intake and exhaust facade for the equipment platform.

[0138] In this embodiment, the exterior of the equipment platform is a resource of equal importance to the area of ​​the equipment platform itself. The air intake velocity in the air intake area of ​​the equipment platform exterior is increased to medium speed (above 4m / s) and the exhaust velocity in the exhaust area is controlled at a moderately high speed (around 8m / s) as a prerequisite for the equipment platform to achieve "heavy load". The positional relationship, area ratio relationship and energy intensity relationship of the air intake and exhaust surfaces on the exterior are reorganized.

[0139] This embodiment adopts a dense arrangement of heavy-duty air conditioning units along the horizontal direction of the equipment platform, and centralizes the exhaust vents of multiple air conditioning units that are isolated on the traditional equipment platform, effectively integrating the resources of the air intake and exhaust areas on the exterior facade, and effectively reducing the boundary length between the exhaust area and the air intake area.

[0140] In this embodiment, a horizontal V-shaped air duct with an opening pointing towards the outer facade is formed between adjacent main units on the equipment platform. The V-shaped air duct on the equipment platform and the opening of the U-shaped finned tube heat exchanger face opposite directions, which is a reverse complementary design. The fin planers on the two adjacent U-shaped finned tube heat exchangers can better distribute the airflow from the outer facade of the equipment platform.

[0141] In this embodiment, a high-speed exhaust zone is set at the top of the equipment platform's exterior facade, and a large-area medium-speed air intake zone is set in the middle and lower part; the air intake zone and exhaust zone are designed to complement each other, with the entire area outside the exhaust zone being the air intake zone, thus expanding the cross-sectional area of ​​the air intake zone.

[0142] This embodiment constructs a high-strength and high-efficiency equipment platform air intake and exhaust facade, laying the foundation for significantly increasing the power density of the equipment platform.

[0143] ②Reduce the footprint of the equipment platform and the width of the building facade.

[0144] This embodiment employs the heavy-duty air conditioning unit described in Embodiments 2 and 3. Within the limited space of the air conditioning unit, a huge area of ​​finned heat transfer surface is further expanded on the ventilation surface of the deep U-shaped large-area finned tube heat exchanger. This effectively increases the total heat transfer area of ​​the fins of the external heat exchanger of the air conditioning unit, reduces the heat transfer temperature difference of the heat exchanger body, increases the evaporation pressure and reduces the condensation pressure, thus forming the characteristics of heavy-duty operation. In this embodiment, in the chain process of medium-speed airflow into the external heat exchanger → dispersion and deceleration → massive heat exchange on the huge ventilation surface → convergence and acceleration → fan pressurization → high-speed discharge, the fan is used as the power source and the area at the massive heat exchanger fins is the lowest airflow velocity zone. This constructs an efficient heat exchange airflow structure inside the air conditioning unit, reflecting the heavy-duty characteristics of the air conditioning unit.

[0145] This embodiment, based on an air conditioning unit with heavy-duty characteristics, innovates the equipment platform layout by incorporating an external heat exchanger fresh air duct within the air conditioning unit, utilizing the unused space at the top of the equipment platform for exhaust duct functions, reducing the lateral spacing between air conditioning units, and combining pedestrian walkways, maintenance walkways, and copper pipe cable tray passages into a single unit. This significantly reduces the floor space occupied by ineffective and inefficient spaces and ventilation blind spots on the equipment platform, increasing the average cooling and heating power density (i.e., cooling and heating capacity per unit area) of the equipment platform from approximately 11.6 kW / m² to over 25 kW / m², a substantial increase of over 100%. Under the same cooling load, it saves half of the equipment platform floor space.

[0146] This embodiment significantly reduces the footprint of the equipment platform under the same building heat load conditions by reorganizing the internal external heat exchanger and the air inlet and outlet paths of the external heat exchanger, reorganizing the spatial structural relationship between the air conditioning unit and the equipment platform, and reorganizing the relationship between the air inlet area and the exhaust area on the exterior facade of the equipment platform. It also significantly reduces the lateral width of the building equipment floor facade occupied by the air inlet and outlet areas of the air conditioning unit, effectively ensuring ventilation, lighting, and visual communication between the interior space of the same floor and the external environment.

[0147] ③ Facilitate air conditioner unit inspection and repair

[0148] In this embodiment, the air conditioning unit integrates the compressor, gas-liquid separator, four-way valve, expansion valve, electrical box, fan, and other refrigerant circuit components into the negative pressure chamber of the heat exchanger.

[0149] This embodiment positions the back panel of the negative pressure chamber of the air conditioner's heat exchanger facing the maintenance channel inside the equipment platform, facilitating the inspection and maintenance of the air conditioner. When a fault occurs, opening the back panel of the negative pressure chamber of the air conditioner's external heat exchanger through the maintenance channel inside the equipment platform provides a clear view of potentially faulty components such as the compressor, gas-liquid separator, four-way valve, expansion valve, electrical box, and fan, making inspection and maintenance extremely convenient. This embodiment solves the inherent inspection and maintenance difficulties of air conditioners. Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the invention and are not intended to limit the implementation of the invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An air conditioning unit, characterized in that, The air conditioning unit is equipped with a finned tube heat exchanger, an air conditioning compressor, a gas-liquid separator, a four-way valve, an expansion valve, an electrical box, and a fan inside its casing. The bottom plate, side plate, back plate, top plate of the shell and the finned tube heat exchanger are combined to form the negative pressure chamber of the heat exchanger; The horizontal cross-section of the finned tube heat exchanger is U-shaped, with the two sides of the U-shaped finned tube heat exchanger being the long sides and the bottom side being the short side; the length ratio of the long side to the short side is 2 to 6:

1. The finned tube heat exchanger has an air inlet side on one side of the cross-section perpendicular to the long side of the fins, and an air outlet side on the other side; the air outlet side belongs to the negative pressure chamber area of ​​the heat exchanger. The air inlet surface is a finned tube heat exchanger, and the angle between the air inlet and the tip of each finned tube heat exchanger is an obtuse angle; the obtuse angle β is 97.5°~135°. The incoming airflow strikes the tip of each fin plate in the finned tube heat exchanger at an obtuse angle β, and is reflected by the fin tip plate into the fin gap and flows into the negative pressure chamber of the heat exchanger. The airflow rate entering each fin gap d is equal to the airflow intercepted by the vertical distance δ between the tips of the two finned plates at the front and rear of the finned tube heat exchanger on the air inlet section. δ=d·sinα / 2, where α is the apex angle α of the extension line of the long side of the heat exchanger; The vertical distance δ between the tips of the front and rear finned tube heat exchangers on the air inlet section is between 0.13d and 0.7d.

2. The air conditioning unit according to claim 1, characterized in that, The fins are arranged vertically and horizontally; the ratio of the length of the long side to the length of the short side is 3 to 4:

1.

3. The air conditioning unit according to claim 1, characterized in that, The airflow velocity between the fins is 1 / 3 of the inlet velocity, corresponding to a vertex angle α of 39° and an obtuse angle β of 109.5° along the extended long side of the heat exchanger.

4. The air conditioning unit according to claim 1, characterized in that, At least two fans are installed above the finned tube heat exchanger along its long side.

5. The air conditioning unit according to claim 1, characterized in that, The fan is either an axial flow fan or a centrifugal fan.

6. The air conditioning unit according to claim 1, characterized in that, The air conditioning compressor, gas-liquid separator, four-way valve, expansion valve, and electrical box are located in the lower middle ventilation blind area of ​​the negative pressure chamber of the finned tube heat exchanger, near the back panel of the air conditioning unit.

7. An air conditioning unit system, characterized in that, It includes at least two air conditioning units as described in any one of claims 1 to 6, the air conditioning units are arranged side by side, and an outward-facing V-shaped air duct is formed between the finned tube heat exchangers of adjacent air conditioning units, the opening of the V-shaped air duct is opposite to the opening of the U-shaped finned tube heat exchanger.

8. The air conditioning unit system according to claim 7, characterized in that, The distance d between adjacent air conditioning units is 3 to 20 cm.

9. The air conditioning unit system according to claim 7, characterized in that, The included angle γ of the V-shaped air duct is 50° to 120°.

10. An air conditioning unit equipment platform, characterized in that, At least one set of the air conditioning host system of claim 7 is arranged horizontally inside the equipment platform; the equipment platform has an exterior facade for ventilation, and the bottom edge of the U-shaped finned tube heat exchanger of the air conditioning host system is close to the exterior facade; an exhaust cavity is provided above the air conditioning host, and the exhaust port of the exhaust cavity is located and / or close to the exterior facade.

11. The air conditioning unit equipment platform according to claim 10, characterized in that, The exterior facade is provided with an exhaust area and an air inlet area; the exhaust area on the exterior facade corresponds to the exhaust cavity of the air conditioning unit, and the air inlet area on the exterior facade corresponds to the air inlet of the air conditioning unit.

12. The air conditioning unit platform according to claim 11, characterized in that, The exhaust zones on the facade are continuously arranged on the upper part of the facade, and the air intake zones on the facade are continuously arranged on the middle and lower parts of the facade.

13. The air conditioning unit equipment platform according to claim 11, characterized in that, The area of ​​the exhaust zone on the facade is 25% to 50% of the facade area used for ventilation.

14. The air conditioning unit platform according to claim 10, characterized in that, The back panel of the air conditioning unit and the inner wall of the equipment platform form a three-in-one passage for pedestrians, maintenance, and installation of copper pipes and cable trays for the air conditioning system.

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