An air conditioner main unit of a bottom plate provided with a folded line type finned tube heat exchanger assembly of a supply air slot

Abstract

This invention belongs to the field of high-efficiency and energy-saving air conditioning technology, and discloses an air conditioning unit with a zigzag-shaped finned tube heat exchanger assembly with a base plate providing a makeup air slot. The unit includes a housing, a finned tube heat exchanger assembly, an air conditioning compressor, a gas-liquid separator, and a fan. The finned tube heat exchanger assembly consists of at least two flat-plate finned tube heat exchangers. The finned tube heat exchanger assembly is located on the air inlet side of the housing. A heightening bracket for mounting the finned tube heat exchanger assembly is provided at the bottom of the housing. At least one makeup air slot is provided on the base plate at the air inlet of the housing, connecting to the space below the base plate. The space extended by the heightening bracket at the bottom of the finned tube heat exchanger assembly connects with the makeup air slot, forming the bottom air inlet channel of the air conditioning unit. This invention improves the vertical uniformity of heat exchanger ventilation; constructs a high-efficiency heat exchange airflow structure for the air conditioning unit, increasing the unit's energy density; and creates conditions for constructing a side-inlet / side-outlet airflow structure to match the external facade of the equipment platform.

Description

Technical Field

[0001] This invention belongs to the field of high-efficiency and energy-saving air conditioning technology, and more specifically, relates to an air conditioning unit with a zigzag finned tube heat exchanger assembly with a base plate having a makeup air slot. Background Technology

[0002] Air conditioning is the most important energy-consuming device in a building and a key focus of building energy conservation.

[0003] The external heat exchanger module of current commercial air conditioning units has evolved from "shell and tube heat exchanger + cooling tower" to air surface cooler. "Finned tube heat exchanger + top-outlet axial fan" has become the standard configuration of external heat exchanger module of commercial air conditioning units. Multi-split units and air-cooled water chiller modules with "finned tube heat exchanger + top-outlet axial fan" as the basic type have gotten rid of the dependence on cooling tower and water source, and improved the environmental adaptability and cooling energy efficiency of air conditioning units.

[0004] The prior art discloses a heat exchanger and an air conditioner having the same (CN114963817A). The heat exchanger includes a core, which includes multiple stacked and spaced partition plates. A flow channel is formed between two adjacent partition plates. The flow channel includes hot channels and cold channels that are alternately arranged along the arrangement direction of the multiple partition plates. A refrigerant fluid flows in the hot channel and a refrigerant fluid flows in the cold channel. The refrigerant fluid and the refrigerant fluid exchange heat in the core. A first partition is provided in the cold channel to change the flow direction of the refrigerant fluid, thereby increasing the flow path of the refrigerant.

[0005] The vertical unevenness of ventilation and heat exchange in the existing multi-split outdoor unit (air conditioning main unit) based on the "finned tube heat exchanger + top-outlet axial flow fan" has been a persistent problem for manufacturers and users.

[0006] The following is a description of the on-site environment and test results of a multi-split air conditioning system performance test organized by the School of Thermal Power Engineering of a certain university: Three outdoor units of a VRV air conditioning system (SANYO ECOi series) were arranged in a straight line on a 0.278-meter-high concrete platform. The maintenance side of each unit was 1.303 meters from the exterior wall. The three units were numbered 1, 2, and 3 from left to right; the distance between units 1 and 2 was 0.426 meters, and the distance between units 2 and 3 was 0.445 meters. The test showed that due to the different vertical distances of the external heat exchangers from the top fan intake, the friction resistance varied greatly. The pressure difference between the inside and outside of the air side of the top finned tubes of the external heat exchangers was significantly greater than that at the bottom. Vertical non-uniformity in ventilation and heat exchange was observed in all three external heat exchangers, particularly severe in units 1 and 3: the ventilation velocity at the top of the external heat exchanger was more than twice the ventilation velocity at the bottom.

[0007] An air conditioner is essentially a "heat transporter." Based on the reverse Carnot cycle principle, it transfers heat from the low-temperature heat source (evaporation or condensation) of the refrigerant in the evaporator and condenser of the refrigeration system through phase change (evaporation or condensation). This is the sole reason for the existence of air conditioners. However, uneven ventilation and heat exchange in an air conditioner's heat exchanger, which essentially means localized inefficient heat exchange or even heat exchange failure, will lead to an imbalance in the refrigerant phase change within the copper pipes of the heat exchanger's various branches. This affects the complete vaporization and necessary superheating of the refrigerant at the evaporator's total outlet, and the complete liquefaction and necessary subcooling of the refrigerant gas at the condenser's total outlet. This reduces evaporation pressure, increases condensation pressure, distorts the operating conditions of the refrigeration and air conditioning system, affects the efficiency of "heat transport," and may even endanger the safety of the air conditioning system's compressor.

[0008] Therefore, how to solve the vertical unevenness of ventilation and heat exchange in the existing top-discharge air conditioning unit, which is "stronger at the top and weaker at the bottom", has become a major technical challenge. Summary of the Invention

[0009] To solve the aforementioned problems in the prior art, the present invention provides an air conditioning unit with a zigzag finned tube heat exchanger assembly having a base plate with a makeup air slot.

[0010] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0011] An air conditioning unit with a zigzag-shaped finned tube heat exchanger assembly with a base plate having a make-up air slot includes a housing, an air conditioning compressor, a gas-liquid separator, and a fan.

[0012] The finned tube heat exchanger assembly consists of at least two flat-plate finned tube heat exchangers; or a V-shaped finned tube heat exchanger formed by bending flat-plate finned tube heat exchangers; or a combination of a flat-plate finned tube heat exchanger and the V-shaped finned tube heat exchanger formed by bending flat-plate finned tube heat exchangers; the cross-section of the finned tube heat exchanger assembly perpendicular to the long side of the fins is a broken line type.

[0013] The long side of the fins of the flat plate finned tube heat exchanger is set in the vertical direction or close to the vertical direction.

[0014] The finned tube heat exchanger assembly is located at the air inlet of the shell and forms a negative pressure chamber of the heat exchanger assembly with at least a portion of the shell, which is connected to the heat exchange air path of the finned tube heat exchanger assembly.

[0015] The bottom of the housing is provided with a heightening bracket for installing the finned tube heat exchanger assembly; the bottom plate at the air inlet of the housing is provided with at least one air supply slot that connects to the space below the bottom plate. The space expanded by the heightening bracket at the bottom of the finned tube heat exchanger assembly is connected to the air supply slot and connected to the atmospheric environment outside the outer facade of the equipment platform, forming the bottom air intake channel of the air conditioning unit.

[0016] Furthermore, the air supply slot provided on the base plate, which connects to the space below the base plate, is positioned opposite to the finned tube heat exchanger in the negative pressure chamber of the heat exchanger assembly, and matches the zigzag edge line on the outer side of the finned tube heat exchanger assembly.

[0017] Furthermore, the finned tube heat exchanger assembly has a V-shaped or N-shaped cross-section perpendicular to the long side of the fins, or is composed of at least two finned tube heat exchangers with a V-shaped cross-section perpendicular to the long side of the fins arranged continuously.

[0018] Furthermore, the cross-section of the finned tube heat exchanger assembly perpendicular to the long side of the fins is W-shaped; preferably, the apex angle α of the V-shaped finned tube heat exchanger is 15° to 110°.

[0019] Furthermore, the bottom plate, side plate, back plate, top plate of the shell and the finned tube external heat exchanger assembly are combined to form the negative pressure chamber of the heat exchanger assembly; the finned tube heat exchanger assembly is the air inlet of the negative pressure chamber of the heat exchanger assembly.

[0020] Furthermore, an air outlet for the negative pressure chamber of the heat exchanger assembly is provided on the top plate at a location away from the finned tube heat exchanger assembly; a fan is provided at the air outlet of the negative pressure chamber of the heat exchanger assembly.

[0021] Furthermore, the heat exchanger assembly has an exhaust chamber at the negative pressure chamber outlet, and the exhaust port of the exhaust chamber is located on the same side as the air inlet inside the housing.

[0022] Furthermore, the exhaust port of the exhaust cavity faces the short side of the air conditioner unit housing.

[0023] Furthermore, the area below the air outlet of the negative pressure chamber of the heat exchanger assembly, adjacent to the back plate, is a ventilation blind zone; the refrigerant circuit components, including the air conditioning compressor, gas-liquid separator, four-way valve, expansion valve, and electrical box, are located in the ventilation blind zone inside the negative pressure chamber.

[0024] Furthermore, the gas-liquid separator, air conditioning compressor, four-way valve, heat exchanger assembly, expansion valve, and refrigerant pipeline of the indoor unit of the air conditioner are sequentially connected to form a refrigerant circulation loop of the air conditioning system.

[0025] Furthermore, the side plate at the air inlet of the housing is provided with several through holes for ventilation of the finned tube heat exchanger assembly; the through holes and the air inlet of the housing constitute the air inlet channel of the finned tube heat exchanger assembly.

[0026] Furthermore, the fan is an axial flow fan or a centrifugal fan.

[0027] Furthermore, the height of the finned tube heat exchanger is 1–1.5 m. The height of the air conditioning unit (excluding the exhaust chamber) is 1.5–2 m.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The beneficial effects of the air conditioning unit of the zigzag finned tube heat exchanger assembly with a base plate equipped with a makeup air slot according to the present invention include:

[0030] ① Improved the vertical uniformity of heat exchanger ventilation.

[0031] This invention addresses the vertical unevenness of ventilation and heat exchange in the finned tube heat exchanger of the top-discharge air conditioning unit, characterized by "stronger at the top and weaker at the bottom." By raising the base plate of the heat exchanger with a heightening bracket, an air supply slot is provided on the base plate at the air inlet of the shell, which matches the bottom foot of the V-shaped finned tube heat exchanger. The air supply slot, together with the side air inlet of the air conditioning unit, supplies air to the finned tube heat exchanger assembly.

[0032] The present invention provides fresh air to the bottom finned tubes of the finned tube heat exchanger assembly through an air supply slot. The location where the air flows into the finned tube heat exchanger is relatively short from the fan intake, resulting in low friction resistance. Furthermore, the airflow direction is upward, consistent with the vertical fin gap direction, eliminating the local resistance caused by lateral airflow turning into the fin gap. This provides the dual advantages of air supply location and direction. The fresh air supplied from the bottom air supply slot increases the fresh air supply to the bottom finned tube heat exchanger, enhances ventilation and heat exchange in the bottom area of ​​the finned tube heat exchanger assembly, and improves the vertical uniformity of ventilation and heat exchange in the finned tube heat exchanger assembly.

[0033] ② Construct a high-efficiency heat exchange air path structure for the air conditioning unit to improve its energy density.

[0034] The present invention adopts an aerodynamic layout with medium-speed air intake in the lower middle part of the short side and high-speed air exhaust at the top, and incorporates the main sections of the air intake and exhaust channels of the finned tube heat exchanger assembly into the air conditioning unit.

[0035] This invention uses a horizontal V-shaped finned tube heat exchanger as the basic unit of the external heat exchanger assembly of the air conditioning unit. Within the limited space of the air conditioning unit, multiple horizontal V-shaped finned tube heat exchangers are continuously arranged parallel to the air inlet surface of the air conditioning unit. A large area of ​​finned tube heat exchanger assembly ventilation surface is obtained by spreading the finned tube heat exchanger assembly along the air inlet surface of the multiple horizontal V-shaped finned tube heat exchangers. A huge area of ​​finned heat transfer surface is obtained by spreading the finned tube heat exchanger assembly ventilation surface a second time.

[0036] 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 airflow slows down and disperses, passing through multiple V-shaped finned tube heat exchangers with a large total ventilation cross-section and a huge total heat exchange area S at a low speed of less than 1.6 m / s and low resistance. After heat exchange, the airflow flows into the negative pressure chamber and converges towards the fan intake under the negative pressure of the fan. After being accelerated and pressurized by the fan, the airflow is finally discharged from the exhaust chamber at a high speed of about 8 m / s.

[0037] The air conditioning unit in this embodiment adopts the above-mentioned aerodynamic layout and airflow structure. In the chain process of medium-speed airflow into the heat exchanger → dispersed deceleration → heat exchange on the huge heat exchange area S of the total ventilation surface → convergence acceleration → fan pressurization → high-speed discharge, the airflow takes the fan as the power source, the negative pressure chamber as the core, and the area with the huge continuous arrangement of V-shaped heat exchanger fins as the lowest speed zone. It completes one fan pressurization and two static pressure-dynamic pressure conversions before and after the fan, which is efficient and smooth, and constructs an efficient heat exchange airflow structure inside the air conditioning unit.

[0038] The present invention's air conditioning unit unfolds a huge finned tube heat exchanger assembly and ventilation surface, and then unfolds a huge finned heat exchange area S on the huge ventilation surface, which reduces the heat transfer temperature difference ΔT of the heat exchanger body, reduces the condensing pressure and increases the evaporating pressure, increases the refrigerant circulation, evaporator heat absorption and condenser heat release, and also effectively controls the volume of the air conditioning unit, increases the energy density of the air conditioning unit, and prepares the preconditions for improving the energy density of the equipment platform.

[0039] ③ Facilitate air conditioner unit inspection and repair

[0040] 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 assembly, close to the back plate. Furthermore, the back plate of the negative pressure chamber of the heat exchanger assembly is located on the short side of the air conditioning unit. When the air conditioning unit is installed on the equipment platform, the back plate of the negative pressure chamber of the heat exchanger assembly faces the maintenance passage on the inner side of the equipment platform.

[0041] 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 invention facilitates inspection and maintenance: when a malfunction occurs, the back panel of the negative pressure chamber of the heat exchanger assembly can be opened through the maintenance channel on the inside of the equipment 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.

[0042] ④ This created conditions for constructing a side-inlet, side-outlet airflow structure to complement the exterior facade of the equipment platform.

[0043] The classic top-discharge central air conditioning unit is tailor-made for rooftop terrace scenarios; moving it from the rooftop terrace to the middle floor equipment platform of the building requires an innovative combination of the air duct of the top-discharge air conditioning unit and the exterior facade of the equipment platform.

[0044] This invention addresses the practical application scenarios where the height of finned tube heat exchangers is limited to approximately 1.2m and the overall height of the main unit is limited to approximately 1.7m in order to control the vertical unevenness of ventilation in central air conditioning units, and where the net height of the equipment floor in high-rise and super high-rise buildings where the central air conditioning unit is installed reaches more than 4m. It 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 intake and exhaust ports set in the same direction and on the same side, and the air intake area: 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 multiple heat exchanger assemblies set along the long side, thus utilizing the idle space at the top of the equipment platform.

[0045] This invention is not only compact in structure, but also features air conditioning unit exhaust and air inlet arranged 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 the side-inlet and side-outlet air path structure of the air conditioning unit in conjunction with the exterior facade of the equipment platform.

[0046] Under the design concept of air conditioner unit air intake area: exhaust area ≈ 2:1, the exhaust speed reaches 2 times the intake speed and the exhaust dynamic pressure head reaches 4 times the intake dynamic pressure head. This effectively improves the exhaust speed and kinetic energy of the air conditioner unit's external heat exchanger, and effectively improves the range and diffusion dilution effect of the air conditioner unit's exhaust jet penetrating the outer facade of the equipment platform and entering the ambient atmosphere. Attached Figure Description

[0047] Figure 1 A three-dimensional structural diagram of the air conditioning unit of the zigzag finned tube heat exchanger assembly with a makeup air slot on the base plate in Example 1;

[0048] Figure 2 A schematic diagram of the airflow operation of the air conditioning unit of the zigzag finned tube heat exchanger assembly with a makeup air slot on the base plate in Example 1;

[0049] Figure 3 A top view of the airflow diagram of the air conditioning unit of the zigzag finned tube heat exchanger assembly with a makeup air slot on the bottom plate in Example 1;

[0050] Figure 4 A side view of the air conditioning unit of the zigzag finned tube heat exchanger assembly with a make-up air slot on the base plate in Example 1;

[0051] Figure 5 for Figure 4 Three horizontal sectional views;

[0052] Figure 6 A schematic diagram of the refrigeration system principle of a horizontal V-shaped finned tube heat exchanger with a makeup air slot on the base plate and a continuously arranged air conditioning unit.

[0053] Figure 7 A three-dimensional structural diagram of a horizontal V-shaped finned tube heat exchanger;

[0054] Figure 8 A three-dimensional structural diagram of a finned tube heat exchanger assembly;

[0055] Figure 9 A horizontal V-shaped finned tube heat exchanger with a makeup air slot on the base plate is continuously arranged in an air conditioning unit. When the unit is running, the "fin planer" at the fin gap inlet intercepts the incoming airflow, slows it down, and then it enters the fin gap for heat exchange before being discharged.

[0056] Figure 10 This diagram illustrates the total temperature difference between the condenser body and the evaporator body, which is the sum of the three temperature differences: the condenser body heat transfer temperature difference, the high-temperature and low-temperature heat source temperature difference, and the evaporator body heat transfer temperature difference.

[0057] Figure 11 The diagram illustrates the pressure-enthalpy relationship of a refrigeration cycle, which is a schematic diagram of the refrigeration cycle. This is because the increase in the total heat exchange area of ​​the external heat exchangers of a refrigeration and air conditioning system leads to an increase in evaporation pressure, resulting in an increase in the heat absorbed by the refrigerant per unit mass, a decrease in compression work, an increase in COP, an increase in the refrigerant circulation volume, and an increase in the heat absorbed by the evaporator and the heat released by the condenser.

[0058] Figure 12 This is a schematic diagram showing the relationship between the air intake and exhaust areas on the exterior of the equipment platform. Detailed Implementation

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] Example 1

[0064] like Figure 1-6 As shown, an air conditioning unit with a zigzag finned tube heat exchanger assembly with a base plate having a make-up air slot includes a housing, a finned tube heat exchanger assembly, an air conditioning compressor 121, a gas-liquid separator 126, and a fan 38.

[0065] The finned tube heat exchanger assembly is located on the air inlet 125 of the shell.

[0066] The bottom plate, side plate, back plate, top plate of the shell and the finned tube external heat exchanger assembly are combined to form the negative pressure chamber 124 of the heat exchanger assembly; the finned tube heat exchanger assembly is the air inlet of the negative pressure chamber 124 of the heat exchanger assembly.

[0067] An air outlet for the negative pressure chamber 124 of the heat exchanger assembly is provided on the top plate at a location away from the finned tube heat exchanger assembly; a fan 38 is installed at the air outlet of the negative pressure chamber 124 of the heat exchanger assembly.

[0068] like Figure 3 As shown, the air outlet of the negative pressure chamber 124 of the heat exchanger assembly 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 inside the housing.

[0069] The exhaust port 331 of the exhaust cavity 33 faces the short side of the air conditioner unit housing.

[0070] like Figure 1-2 As shown, the bottom of the housing is provided with a heightening bracket 136 for installing the finned tube heat exchanger assembly; the bottom plate at the air inlet 125 of the housing is provided with three make-up air slots 141 that connect to the space below the bottom plate. The space expanded by the heightening bracket 126 at the bottom of the finned tube heat exchanger assembly is connected to the make-up air slots 141 and connected to the atmospheric environment outside the outer facade 1 of the equipment platform, forming the air inlet channel 135 at the bottom of the air conditioning unit.

[0071] The air supply slot 141, which connects to the space below the base plate, is set opposite to the finned tube heat exchanger in the negative pressure chamber 124 of the heat exchanger assembly and matches the zigzag edge line on the outer side of the finned tube heat exchanger assembly.

[0072] like Figure 1-2 As shown, the area below the air outlet of the negative pressure chamber 124 of the heat exchanger assembly, 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, and electrical box, are located within this ventilation blind zone inside the negative pressure chamber 124 of the heat exchanger assembly.

[0073] The gas-liquid separator 126, the air conditioning compressor 121, the four-way valve, the heat exchanger assembly, the expansion valve, and the refrigerant pipeline of the indoor unit of the air conditioner are connected in sequence to form the refrigerant circulation loop of the air conditioning system.

[0074] The side plate at the air inlet 125 of the shell is provided with several through holes 138 for ventilation of the finned tube heat exchanger assembly; the through holes 138 and the air inlet 125 of the shell constitute the air inlet channel 135 of the finned tube heat exchanger assembly.

[0075] Fan 38 is either an axial flow fan or a centrifugal fan.

[0076] like Figure 7-9 As shown, the finned tube heat exchanger assembly of this embodiment consists of four flat-plate finned tube heat exchangers 37; or it consists of two continuously arranged V-shaped finned tube heat exchangers 40 with cross-sections perpendicular to the long side of the fins. The V-shaped finned tube heat exchanger 40 consists of two flat-plate finned tube heat exchangers 37.

[0077] like Figure 10 As shown, the flat plate 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.

[0078] The cross-section of the finned tube heat exchanger assembly perpendicular to the long side of the fins is a broken line, or more specifically, a W-shaped section.

[0079] The long side of the fins in the flat plate finned tube heat exchanger 37 is set in the vertical direction or close to the vertical direction.

[0080] The apex angle α of the V-shaped finned tube heat exchanger is 15° to 110°.

[0081] As an optional implementation, the apex angle α of the V-shaped finned tube heat exchanger is 30° to 90°.

[0082] As an optional implementation, the apex angle α of the V-shaped finned tube heat exchanger is 30° to 60°.

[0083] like Figure 9 As shown, the finned tube heat exchanger assembly has one side perpendicular to the fin section as the air inlet side and the other side as the air outlet side; the air outlet side belongs to the negative pressure chamber area of ​​the heat exchanger assembly.

[0084] The incident surface of the inlet airflow is each flat finned tube heat exchanger in the finned tube heat exchanger assembly. The angle between the inlet airflow and the tip of each finned plate 110 on each flat finned tube heat exchanger 37 is an obtuse angle β. The obtuse angle β is 97.5° to 145°. The inlet airflow strikes the tip of each finned plate 110 in the finned tube heat exchanger assembly 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 assembly.

[0085] The airflow rate entering each fin gap d is equal to the airflow intercepted by the vertical distance δ between the tips of the front and rear fin plates of the flat plate finned tube heat exchanger in the air inlet section.

[0086] δ=d·sinα / 2, where α is the apex angle of the V-shaped finned tube heat exchanger;

[0087] 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.

[0088] In one specific implementation, the airflow velocity between the fins is 1 / 3 of the inlet velocity, corresponding to a vertex angle α of 39° and an incident obtuse angle β of 109.5° for the V-shaped finned tube heat exchanger.

[0089] The core objective of optimizing refrigeration (heat pump) air conditioning units in different application scenarios remains "reducing condensing pressure and increasing evaporating pressure": reducing refrigeration condensing pressure can directly reduce the compressor's compression work; while increasing the heat pump heating evaporating pressure (evaporating temperature) means increasing the refrigerant circulation, increasing the evaporator's heat absorption, increasing the condenser's heat release, and reducing the compression ratio and compressor discharge temperature.

[0090] In this embodiment, evaporation pressure (evaporation temperature) is taken as the first factor of the refrigeration and air conditioning system. This is because evaporation pressure determines the density of the low-pressure refrigerant gas drawn into the compressor and the compressor's compression ratio. If the evaporation pressure of the heat exchanger (evaporator) of the heat pump air conditioner unit increases from 5 kg to 6 kg in winter, the system's refrigerant circulation, evaporator heat absorption, and condenser heat release will all increase by about 20% simultaneously, and the compressor's compression ratio and compressor discharge temperature will also drop accordingly.

[0091] This embodiment analyzes the relationship between the heat transfer capacity Q of finned tube heat exchangers such as air conditioner evaporators and condensers and the overall heat transfer coefficient K, heat transfer area S, and the heat transfer temperature difference Δt between refrigerant and air, expressed as Q = K × S × Δt. It proposes the technical judgment that "the key factors for improving the evaporation pressure of the current air conditioning unit, reducing the condensation pressure, improving the heat transfer capacity Q of the external heat exchanger of the air conditioning unit, and improving the COP of the refrigeration and air conditioning system lie in increasing the total heat transfer area S of the finned tube heat exchanger."

[0092] This embodiment expands the heat exchange area of ​​the evaporator / condenser, which not only increases the heat exchange capacity of the heat exchanger but also improves the performance of the refrigeration and air conditioning system. Expanding the heat exchange area and reducing the heat exchange temperature difference are not only objective requirements for the iterative upgrade of heat exchangers but also core requirements for the iterative upgrade of large-scale refrigeration and air conditioning systems constructed with the participation of heat exchangers.

[0093] like Figure 10 As shown, the difference between condensing temperature and evaporating temperature (T2-t2) is the fundamental factor determining the core indicator COP of the refrigeration and air conditioning system. A higher (T2-t2) will result in a lower COP, and vice versa. The COP of the refrigeration and air conditioning system is inversely related to the difference between condensing temperature and evaporating temperature (T2-t2). The difference between condensing temperature and evaporating temperature (T2-t2) is the sum of three temperature differences: the condenser body heat transfer temperature difference (T2-T1), the high-temperature heat source and low-temperature heat source temperature difference (T1-t1), and the evaporator body heat transfer temperature difference (t1-t2). Therefore, given that the temperature difference between the high-temperature heat source and the low-temperature heat source (T1-t1) is an objective reality that cannot be changed, the innovative reduction of the heat transfer temperature difference between the condenser body (T2-T1) and the evaporator body (t1-t2) is the only way to reduce the difference between the condensing temperature and the evaporating temperature (T2-t2) in the air conditioning heat pump system. This is the only way to reduce the system condensing pressure (condensing temperature), increase the system evaporating temperature (evaporating pressure), increase the system refrigerant circulation, increase the heat absorption of the evaporator and the heat release of the condenser, and increase the COP of the refrigeration and air conditioning system.

[0094] like Figure 11 As shown, this invention reduces the body heat transfer temperature difference between the evaporator and condenser by increasing the total heat transfer area S of the finned tube heat exchanger, thereby increasing the evaporation pressure and decreasing the condensation pressure. This achieves the goals of increasing refrigerant circulation, evaporator heat absorption, condenser heat release, and the COP of the refrigeration system. The technical effect of increasing the total heat transfer area of ​​the external heat exchanger is particularly evident in the improvement of the evaporation temperature and evaporation pressure of the evaporator.

[0095] Evaporation pressure is the primary factor in heat pump systems, and its impact on the performance of refrigeration and heat pump systems is as follows: Figure 2 As shown (the vertical axis represents condensation pressure, and the horizontal axis represents enthalpy; 1-2-3-4 in the figure represents the original circulation path, and 1-2-3'-4 represents the circulation path of this invention):

[0096] (1) The increase in evaporation pressure (P1→P1') directly leads to an increase in the heat absorbed by the refrigerant per unit mass in the refrigeration system (h4'-h4) and a decrease in the compressor's compression work (h4'-h4), thereby improving the energy efficiency ratio;

[0097] (2) The increase in evaporation pressure (P1→P1') also directly leads to an increase of approximately (P1' / P1-1)×100% in the refrigerant circulation of the fixed frequency heat pump system, resulting in an increase of approximately (P1' / P1-1)×100% in the heat absorption power of the evaporator and the heating power of the condenser.

[0098] (3) Increased evaporation pressure also directly leads to a decrease in compression ratio and a decrease in compressor exhaust temperature, effectively inhibiting the deterioration of lubricating oil and the degradation of compressor motor insulation performance.

[0099] When the finned tube heat exchanger assembly of the present invention is running, the microscopic process of airflow entering and exiting the fin gap and flowing at low speed in the fin gap is the central link of the airflow field of the finned tube heat exchanger assembly.

[0100] like Figure 9 As shown, 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.

[0101] In this embodiment, the air conditioning unit is applicable to scenarios where the air conditioning unit location is changed from an open outdoor platform to a semi-enclosed equipment platform under the conditions of a building distributed energy system; the air inlet and outlet air field of the air conditioning unit is changed from a classic hemispherical three-dimensional open space to a semi-enclosed outer corridor equipment platform with one side open.

[0102] In current refrigeration and air conditioning systems, the widespread use of corrugated fins, slotted fins, and internally threaded copper tubes in finned tube heat exchangers such as evaporators and condensers has brought the overall heat transfer coefficient K of the external heat exchanger of the air conditioning unit close to its peak value, and the marginal effect of further optimizing the K value has sharply decreased. However, under specific low-temperature and high-temperature heat source scenarios, that is, under the specific conditions where the temperature, humidity, and other thermophysical properties of the high-temperature and low-temperature media in which the condenser and evaporator operate are determined, increasing the ΔT between the low-temperature medium between the evaporator fins (e.g., low-temperature indoor air in summer) and the refrigerant in the copper tubes will inevitably lower the evaporation temperature and evaporation pressure. On the other hand, increasing the ΔT between the high-temperature and high-pressure refrigerant gas in the condenser copper tubes and the high-temperature medium between the fins (e.g., high-temperature ambient air in summer) will inevitably raise the condensation pressure and condensation temperature. Therefore, increasing the heat transfer temperature difference ΔT of the heat exchanger body, such as the evaporator and condenser, impairs the refrigerant circulation, heat absorption capacity, heat release capacity, and COP of the entire refrigeration system.

[0103] This embodiment focuses on the problem of heat exchanger ventilation and heat transfer uniformity. Based on the technology of "increasing the total heat transfer area of ​​the heat exchanger to improve the evaporation pressure of the air conditioning system, reduce the condensation pressure, and improve the heat exchange capacity," it improves the ventilation and heat transfer uniformity of the heat exchanger by expanding the heat transfer area of ​​the finned tube heat exchanger. This embodiment also features systematic innovation in the structure of the external heat exchanger of the air conditioning unit and the airflow path structure of the external heat exchanger.

[0104] ① Constructing an external heat exchanger assembly

[0105] In this embodiment, a horizontal V-shaped finned tube heat exchanger is used as the basic unit. Finned tube heat exchanger assemblies are continuously arranged parallel to the air inlet of the air conditioning unit, thus constructing an air conditioning unit finned tube heat exchanger assembly with a large area of ​​external heat exchanger assembly ventilation surface and a huge area of ​​finned heat transfer surface. Furthermore, the main section of the air inlet channel of the finned tube heat exchanger assembly is incorporated into the air conditioning unit, reducing the traditional external air inlet and outlet channels of the air conditioning unit.

[0106] ② Remodeling the air inlet of the finned tube heat exchanger assembly

[0107] In this embodiment, within the limited internal space of the air conditioning unit, multiple horizontal V-shaped finned tube heat exchangers are deployed along their air inlet surfaces to obtain a large area of ​​finned tube heat exchanger assembly ventilation surface. Further deployment on this large area creates a massive finned heat transfer surface, effectively expanding the total finned heat transfer area of ​​the external heat exchanger assembly of the air conditioning unit. During operation, the airflow is driven by negative pressure in the negative pressure chamber, continuously dispersing the incoming airflow. Multiple fin planers are used to progressively plan the incoming airflow, reducing the incoming air velocity and reshaping the air inlet field of the external heat exchanger assembly.

[0108] ③ Set up an air supply slot that fits the bottom of the V-shaped finned tube.

[0109] This embodiment addresses the vertical "stronger at the top and weaker at the bottom" unevenness in ventilation and heat exchange of the external heat exchanger of the top-discharge air conditioning unit by raising the finned tube heat exchanger assembly and setting an air supply slot on the bottom plate of the finned tube heat exchanger assembly that matches the bottom foot of the V-shaped finned tube; the air supply slot and the side air inlet of the air conditioning unit work together to supply air to the finned tube heat exchanger assembly.

[0110] In this embodiment, the air supply slot provides fresh air to the bottom finned tubes of the finned tube heat exchanger assembly. The location where the air flows into the finned tube heat exchanger is relatively close to the fan intake, resulting in low friction resistance. Furthermore, the airflow direction is upward, consistent with the vertical fin gap direction, eliminating the local resistance caused by lateral airflow turning into the fin gap. This provides the dual advantages of air inlet location and direction. The fresh air supplied from the bottom air supply slot increases the fresh air supply to the bottom finned tube heat exchanger, enhances ventilation and heat exchange in the bottom area of ​​the finned tube heat exchanger assembly, and improves the vertical uniformity of ventilation and heat exchange in the finned tube heat exchanger assembly.

[0111] This embodiment achieves a systematic innovation in the structure of the finned tube heat exchanger assembly of the air conditioning unit and the airflow structure of the finned tube heat exchanger assembly. It constructs a finned tube heat exchanger assembly with a large ventilation surface and a huge heat exchange surface, reshapes the air inlet field of the finned tube heat exchanger assembly, and sets a makeup air slot that fits the bottom of the V-shaped finned heat exchanger. This expands S, improves the uniformity of ventilation and heat exchange, reduces the heat transfer temperature difference ΔT of the heat exchanger body, and increases the evaporation pressure of the air conditioning system while reducing the condensation pressure.

[0112] like Figure 6 As shown, in this embodiment, the air conditioning unit places the compressor, four-way valve, expansion valve, gas-liquid separator, and other refrigeration circuit components in the lower middle part of the negative pressure chamber of the heat exchanger assembly, close to the back plate of the negative pressure chamber. This area is precisely the ventilation blind spot of the negative pressure chamber of the heat exchanger assembly. These components, together with the finned tube heat exchanger, refrigerant connecting pipe, indoor unit heat exchanger, and other components, form a refrigeration and air conditioning circulation loop in the order of compressor-four-way valve-condenser-expansion valve-evaporator-four-way valve-gas-liquid separator-compressor. The compressor, acting as the power source for the refrigeration cycle, establishes high and low pressure states for the refrigerant in the condenser and evaporator pipes, respectively. This drives the refrigerant to circulate and undergo repeated phase changes within the refrigeration cycle to achieve "heat transfer." Specifically, the refrigerant liquid absorbs heat as it evaporates within the evaporator pipes, and then absorbs heat from the low-temperature ambient air flowing between the fins through the large heat-absorbing area S of the copper tubes. Conversely, the high-temperature, high-pressure refrigerant gas releases heat as it condenses within the condenser pipes, and then releases heat to the high-temperature ambient air flowing between the fins through the large heat-releasing area S of the copper tubes. This process achieves the migration of heat from the low-temperature environment where the evaporator is located to the high-temperature environment where the condenser is located.

[0113] like Figure 12As shown, during the operation of the air conditioning unit in this embodiment, the fan in the negative pressure chamber of the heat exchanger assembly draws air from the negative pressure chamber connected to its air intake, creating negative pressure within the chamber. This negative pressure pulls the air outside the finned tube heat exchanger at a medium speed of approximately 4 m / s through the vertical air inlet and bottom air supply slot of the unit into the heat exchanger assembly inside the unit. After entering the heat exchanger assembly of the air conditioning unit, the outside air is dispersed and decelerated, flowing towards the finned tube heat exchanger assembly with its large total ventilation cross-section and huge fin area. It flows through the gaps between the fins at a low speed and low resistance of less than 1.6 m / s, achieving heat exchange between the ambient air and the refrigerant in the heat exchange tube 115. After heat exchange, the air entering the negative pressure chamber is then gathered and accelerated, flowing into the fan air intake with the lowest pressure. It is then pressurized and accelerated by the fan, passing through the exhaust chamber and discharged outward at a high speed of more than 8 m / s.

[0114] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present 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 with a zigzag-shaped finned tube heat exchanger assembly having a base plate with a makeup air slot, characterized in that, Includes the shell, finned tube heat exchanger assembly, air conditioning compressor, gas-liquid separator and fan; The finned tube heat exchanger assembly consists of a V-shaped finned tube heat exchanger composed of at least two flat-plate finned tube heat exchangers; or a V-shaped finned tube heat exchanger formed by bending a flat-plate finned tube heat exchanger; or a combination of a flat-plate finned tube heat exchanger and the V-shaped finned tube heat exchanger formed by bending a flat-plate finned tube heat exchanger; the cross-section of the finned tube heat exchanger assembly perpendicular to the long side of the fin is a broken line type. The long side of the fins in the flat plate finned tube heat exchanger is arranged vertically. The finned tube heat exchanger assembly is located at the air inlet of the shell and, together with the bottom plate, side plate, back plate, top plate of the shell and the finned tube external heat exchanger assembly, forms the negative pressure chamber of the heat exchanger assembly; the finned tube heat exchanger assembly serves as the air inlet of the negative pressure chamber of the heat exchanger assembly. The bottom of the housing is provided with a heightening bracket for installing the finned tube heat exchanger assembly; the bottom plate at the air inlet of the housing is provided with at least one air supply slot that connects to the space below the bottom plate; the space expanded by the heightening bracket at the bottom of the finned tube heat exchanger assembly is connected to the air supply slot and connected to the atmospheric environment outside the outer facade of the equipment platform, forming the bottom air intake channel of the air conditioning unit. The side of the finned tube heat exchanger assembly perpendicular to the fins is the air inlet side, and the other side is the air outlet side; the air outlet side belongs to the negative pressure chamber area of ​​the heat exchanger assembly. The incident surface of the airflow is each finned tube heat exchanger in the finned tube heat exchanger assembly. The angle between the airflow and the tip of each finned tube heat exchanger is an obtuse angle β. The airflow impacts the tip of each finned tube heat exchanger assembly at an obtuse angle β, is reflected by the fin tip, enters the fin gap, and flows into the negative pressure chamber of the heat exchanger assembly. The obtuse angle β is 97.5° to 145°; The airflow rate entering each fin gap d is equal to the airflow intercepted by the vertical distance δ between the tips of the front and rear fin plates of the finned tube heat exchanger in the air inlet section; δ=d·sinα / 2, where α is the apex angle of the V-shaped finned tube heat exchanger.

2. The air conditioning unit of the zigzag finned tube heat exchanger assembly with a base plate provided with a make-up air slot as described in claim 1, characterized in that, The air supply slot provided on the base plate, which connects to the space below the base plate, is positioned opposite to the finned tube heat exchanger in the negative pressure chamber of the heat exchanger assembly, and matches the zigzag edge line on the outer side of the finned tube heat exchanger assembly.

3. The air conditioning unit of the zigzag finned tube heat exchanger assembly with a base plate provided with a make-up air slot as described in claim 1, characterized in that, The finned tube heat exchanger assembly has a V-shaped or N-shaped cross-section perpendicular to the long side of the fins, or is composed of at least two finned tube heat exchangers with a V-shaped cross-section perpendicular to the long side of the fins arranged continuously.

4. The air conditioning unit of the zigzag finned tube heat exchanger assembly with a base plate provided with a make-up air slot as described in claim 1, characterized in that, The cross-section of the finned tube heat exchanger assembly perpendicular to the long side of the fins is W-shaped.

5. The air conditioning unit of the zigzag finned tube heat exchanger assembly with a base plate provided with a make-up air slot as described in claim 1, characterized in that, An air outlet for the negative pressure chamber of the heat exchanger assembly is provided on the top plate at a distance away from the finned tube heat exchanger assembly; a fan is provided at the air outlet of the negative pressure chamber of the heat exchanger assembly.

6. The air conditioning unit of the zigzag finned tube heat exchanger assembly with a base plate provided with a makeup air slot as described in claim 5, characterized in that, The heat exchanger assembly has an exhaust chamber at the negative pressure chamber outlet, and the exhaust port of the exhaust chamber is located on the same side as the air inlet inside the housing.

7. The air conditioning unit of the zigzag finned tube heat exchanger assembly with a base plate provided with a make-up air slot as described in claim 6, characterized in that, The exhaust port of the exhaust chamber faces the short side of the air conditioner unit housing.

8. The air conditioning unit of the zigzag finned tube heat exchanger assembly with a base plate provided with a make-up air slot as described in claim 1, characterized in that, The area below the air outlet of the heat exchanger assembly's negative pressure chamber, adjacent to the back plate, is a ventilation blind zone; the refrigerant circuit components, including the air conditioning compressor, gas-liquid separator, four-way valve, expansion valve, and electrical box, are located inside the negative pressure chamber in this ventilation blind zone. The gas-liquid separator, air conditioning compressor, four-way valve, heat exchanger assembly, expansion valve, and refrigerant pipeline of the indoor unit of the air conditioner are connected in sequence to form the refrigerant circulation loop of the air conditioning system.

9. The air conditioning unit of the zigzag finned tube heat exchanger assembly with a base plate provided with a make-up air slot as described in claim 1, characterized in that, The side plate at the air inlet of the shell is provided with several through holes for ventilation of the finned tube heat exchanger assembly; the through holes and the air inlet of the shell constitute the air inlet channel of the finned tube heat exchanger assembly.

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