Indoor heat exchange unit having windward side margin area

Abstract

The utility model discloses an indoor heat exchange unit with windward side blank area belongs to heat exchange technical field for realizing the heat exchange of first fluid and second fluid, aims at solving the problem of first fluid air intake uneven, heat exchange efficiency is limited because of the traditional heat exchange unit causes coil full cloth, this heat exchange unit includes the body, and the body is by a plurality of mutually separate interval and parallel arrangement's fin, and the disc pipe component that penetrates the fin, supplies second fluid in with first fluid flow direction intersection direction flow -through constitutes, the body has total thickness D along the X -axis direction of first fluid flow direction, and divides into windward side blank area X1 section and disc pipe arrangement area X2 section along the X -axis, wherein X1 section width is 1 / 4 to 1 / 2 of D, and X2 section width is 1 / 2 to 3 / 4 of D, and disc pipe component only is established in X2 section, and the uniformity of first fluid air intake is optimized through windward side blank design, reduces air resistance and wake interference, effectively promotes heat exchange efficiency, and simplifies disc pipe layout to reduce material cost simultaneously.

Description

Technical Field

[0001] This utility model relates to the field of heat exchange technology for parking air conditioning, specifically to an optimized evaporator structure for use in the cooling mode of parking air conditioning. Background Technology

[0002] A parking air conditioner is an air conditioner that operates on a battery while the vehicle is parked and waiting or resting. It is mainly used in large vehicles such as trucks, RVs, and buses. It does not rely on the vehicle's engine for power and can be directly connected to the vehicle's battery. It can work normally even when the engine is off. It uses a DC 12V / 24V / 36V vehicle battery for power supply. The cooling system usually uses safe and environmentally friendly R134a refrigerant. The main structural forms are split type and integrated type. The integrated parking air conditioner is installed on the top above the driver's cab. It has a high degree of integration and does not require drilling.

[0003] Parking air conditioner evaporators typically have a fin spacing of 1.2-2mm, using dense fins to increase the heat exchange area. The fin design is primarily corrugated, with the mainstream design combining copper tubes and aluminum foil fins. Copper tubes provide high thermal conductivity, while aluminum foil fins expand the heat exchange area and are less expensive. Parking air conditioner evaporators generally employ a design where coils are continuously arranged along the airflow direction, such as a conventional three-row coil configuration, with the coils covering the entire airflow side.

[0004] Parking air conditioners are characterized by their small parking space and independent low-power consumption. Traditional air conditioning heat exchangers are not very effective in the field of parking air conditioning heat exchange technology, so it is necessary to improve the indoor heat exchange unit of parking air conditioners. Utility Model Content

[0005] To address the above problems, this utility model provides an indoor heat exchange unit with a windward blank area, which enables heat exchange between a first fluid and a second fluid. The unit includes a body comprising multiple fins and a coil assembly inserted within the fins. Multiple fins are spaced apart from each other and arranged in parallel to form a space for the first fluid to flow. A coil assembly comprising a plurality of heat-conducting tubes extending through the plurality of fins and supplying a second fluid in a direction intersecting with the direction of flow of a first fluid. The body has a total thickness D along the X-axis direction of the first fluid flow direction, and is divided into a windward blank area X1 section and a coil arrangement area X2 section along the X-axis direction. The width of the windward blank area X1 section is 1 / 4 to 1 / 2 of the total thickness D, and the width of the coil arrangement area X2 section is 1 / 2 to 3 / 4 of the total thickness D.

[0006] This technical solution effectively avoids the airflow congestion problem caused by traditional evaporators being fully covered with coils by dividing the air intake area (X1) along the X-axis of the main body into a blank area with a width of 1 / 4 to 1 / 2 of the total thickness (D). Furthermore, the coil assembly is only installed in the coil arrangement area (X2). Because no coils are installed in section X1, the friction resistance of the airflow through the main body is reduced. This also solves the problem of poor airflow caused by the windward baffle of the parking air conditioner's water inlet obstructing the lower part of the indoor heat exchange unit. The blank space in section X1 guides airflow to more smoothly cover the lower area of ​​the main body, improving air intake capacity and significantly improving the performance of the indoor heat exchange unit of the parking air conditioner.

[0007] Preferably, the width of the windward blank area X1 is 1 / 3 of the total thickness D, and the width of the coil arrangement area X2 is 2 / 3 of the total thickness D. More preferably, at least two rows of coils are arranged along the X-axis within the coil arrangement area X2, each row containing branch A and branch B, with the two branches arranged alternately within each row. Each coil within the coil arrangement area X2 includes branch A (top inlet, bottom outlet) and branch B (bottom inlet, top outlet), with the two branches arranged alternately along the height direction, ensuring that the refrigerant flow direction of adjacent pipes in the same row is opposite and / or the temperature gradient is complementary.

[0008] Preferably, the two rows of coils within the X2 section of the coil arrangement area are staggered in the two adjacent pipe channels in the vertical direction. This avoids continuous obstruction and wake problems caused by channel alignment after the airflow passes through the previous row of coils. Compared to channel alignment, the staggered design makes the airflow path smoother, reduces the wake area by 30%-40%, and lowers the overall wind resistance of the evaporator.

[0009] The beneficial effects of this application will be further explained in specific embodiments. Attached Figure Description

[0010] Figure 1 The three-dimensional view of the parking air conditioner in this utility model after removing part of the upper cover; Figure 2 for Figure 1 The 3D view of the parking air conditioner after removing the evaporator has been further enhanced. Figure 3 This is a perspective view of the indoor heat exchange unit of the parking air conditioner in this utility model; Figure 4 for Figure 3 Perspective view; Figure 5 for Figure 3 The left view; Figure 6 This is a first perspective view of the coil of the indoor heat exchange unit of the parking air conditioner in this utility model; Figure 7This is a second perspective view of the coil of the indoor heat exchange unit of the parking air conditioner in this utility model. Detailed Implementation

[0011] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0012] The parking air conditioner operates on the same principle as a conventional air conditioner. An indoor heat exchange unit 2, an indoor fan 3, a compressor 6, an outdoor heat exchange unit 5, an expansion valve, and a controller are installed on the base 1, forming a heat pump circulation system. The indoor heat exchange unit 2 and the outdoor heat exchange unit 5 can be selectively used as condensers or evaporators, respectively. When the indoor heat exchange unit 2 acts as a condenser, the parking air conditioner operates in heating mode; when the indoor heat exchange unit 2 acts as an evaporator, the parking air conditioner operates in cooling mode. On the outdoor side, due to the action of the outdoor fan 4, airflow from the outside environment is introduced through the outdoor air inlet, passes upwards through the outdoor heat exchange unit 5, and is further discharged upwards from the outdoor fan 4, completing the heat exchange between the outdoor air and the heat exchanger.

[0013] A water receiving trough is provided on the base 1. The water receiving trough has a windward baffle 8 and a leeward baffle 9, and a water guiding space between them. The water receiving trough is also provided with a support rib 10. The bottom of the indoor heat exchange unit 2 rests on the support rib 10 of the water receiving trough. When the indoor heat exchange unit 2 acts as an evaporator, the parking air conditioner operates in cooling mode. The refrigeration system of the parking air conditioner compresses the refrigerant into a high-temperature, high-pressure gas through the compressor. After being dissipated by the outdoor heat exchange unit 5, which acts as a condenser, it becomes a low-temperature, high-pressure liquid. The low-temperature, high-pressure liquid enters the indoor heat exchange unit 2, which acts as an evaporator, through the expansion valve or throttle valve and the air intake pipe 27. In the evaporator, it rapidly depressurizes and evaporates, absorbing a large amount of heat, causing the temperature of the evaporator fins and coils to drop below the air dew point, typically 5°C to 10°C. Water vapor in the air condenses upon contact with the condenser. During this process, the indoor fan 3 blows hot, humid air from the cab across the evaporator fins. When the humid air comes into contact with the low-temperature evaporator surface, the temperature of the water vapor in the air rapidly drops below the dew point temperature, and the water vapor loses heat and condenses into liquid water. As the indoor heat exchange unit 2, acting as the evaporator, operates, the condensed water droplets adhere to the fin surface of the indoor heat exchange unit 2, gradually accumulating into water droplets that flow down the fins and drip into the water collection tank of the base 1. The bottom of the water collection tank has a drain hole and a drain pipe to lead the condensate outside the vehicle for discharge, typically dripping onto the ground or under the vehicle.

[0014] In the entire unit, indoor heat exchange unit 2 is placed vertically. The condensate produced collects downwards due to gravity. However, the fin spacing is typically only 1.4-2mm, making it easy for liquid water to form a "water film" or "water droplet bridge" between the fins. This reduces the cross-sectional area of ​​the airflow channel, significantly increasing airflow resistance. Ultimately, this results in a much lower actual airflow rate in the lower half of the fins compared to the upper half. Based on the heat calculation formula related to specific heat capacity: Q = cmΔt, where c is the specific heat capacity of air, m is the mass flow rate, and Δt is the temperature difference. Since the heat exchange rate is positively correlated with the air volume, the lower section cannot fully exchange heat with the low-temperature fins due to insufficient air volume, resulting in an uneven heat exchange phenomenon of "strong at the top and weak at the bottom". Because the fan power is usually lower when the vehicle is parked than when it is in motion, the air volume reserve is insufficient and it is more susceptible to the effects of condensate. This problem is particularly prominent in parking air conditioners.

[0015] Improve refrigerant flow This invention designs an airflow path of "dual intake branch pipes penetrating the entire fin area and crossing each other," allowing the airflow from both ends of the evaporator to penetrate the entire height of the fin area before converging and exiting. The specific structure is as follows: The first branch pipe 21, referred to as branch A, enters from the top and exits from the bottom in the indoor heat exchange unit 2, and runs through the entire area. The first air inlet branch pipe 23 at the air inlet end of branch A is connected to the air inlet pipe 27. Branch A adopts a conventional coiled structure. After entering horizontally from the top of the indoor heat exchange unit 2, it repeatedly coils downwards along the vertical direction of the evaporator. The number of coils is adapted to the height of the indoor heat exchange unit 2 to ensure that branch A can cover the entire height of the indoor heat exchange unit 2. The second branch pipe 22, referred to as branch B, enters from the bottom and exits from the top in the indoor heat exchange unit 2. The branch pipe structure is symmetrical to that of branch A. After entering horizontally from the bottom of the evaporator, it repeatedly coils upwards in the vertical direction.

[0016] The first return air branch pipe 25, which is led out from the lower end of the indoor heat exchange unit 2 by the first branch pipe 21, merges with the second return air branch pipe 26, which is led out from the upper end of the indoor heat exchange unit 2 by the second branch pipe 22, and then forms a return air pipe 28. This forms an indoor heat exchange unit 2 with "dual branches running through the entire area and cross-circulation", achieving uniform heat exchange. The aforementioned indoor heat exchange unit 2 breaks away from the traditional segmented coverage mode of evaporators, which is a technical bias of segmented small branch circulation. Branch B enters from the bottom and exits from the top, and the airflow acts on the fins throughout the entire height range of the indoor heat exchange unit 2. Since it first enters from the bottom of the indoor heat exchange unit 2, it compensates for the insufficient heat exchange caused by the accumulation of condensate in the lower half of the evaporator, which affects the airflow. Branch A enters from the top and exits from the bottom, and the airflow covers the upper half of the indoor heat exchange unit 2 while extending downward to the bottom area. It forms a cross coverage with the refrigerant airflow of branch B in the middle and lower parts of the evaporator, eliminating the airflow blind spots at the segmented connection of the traditional evaporator and reducing the difference in airflow throughout the entire area. Priority is given to using three temperature sensors to monitor the temperature of the evaporator in real time across the entire area (bottom, middle, and top), and installing a diversion valve in the intake pipe 27 to distribute and control the refrigerant flow in branch A and branch B, ensuring the temperature field of the entire indoor heat exchange unit 2 remains stable, forming a closed-loop control system of "monitoring-regulation".

[0017] Improve coil layout In the cooling mode, the core heat exchange component of the parking air conditioner's indoor heat exchange unit is the evaporator. This evaporator is usually defined along the airflow direction as "front air → outlet air direction", that is, the X-axis direction, and multiple rows of coils are arranged to increase the heat exchange capacity by increasing the heat exchange area.

[0018] There is a common technical bias in existing technologies, which assumes that the coils should fill the X-axis thickness region of the evaporator as much as possible, i.e., maximizing the heat exchange capacity by maximizing the number of coil rows. For example, in a conventional three-row coil design, the first, second, and third rows of coils are arranged sequentially along the X-axis. However, in practical applications, it has been found that the above three-row coil design has two major drawbacks: The first issue is wake interference. When the airflow passes through the first row of coils near the windward side, a low-speed turbulent wake zone is formed in the leeward area of ​​the pipe. The airflow velocity in this wake zone is uneven and the heat transfer coefficient is reduced, which greatly reduces the actual heat transfer efficiency of the second and third rows of coils. Secondly, there is the problem of insufficient air intake. The indoor heat exchange unit 2 needs to be fixed in the water collection tank. The vertical height of the water collection tank's windward baffle 8 will block the lower area of ​​the evaporator, resulting in a lower airflow velocity in this area compared to the middle and upper sections. The lower piping of the first row of coils is located in this low air intake zone, and its heat exchange efficiency is only 30% of that of the middle and upper piping. Furthermore, the wake generated by the inefficient piping will further deteriorate the heat exchange environment of the second and third rows of coils. The aforementioned defects result in the parking air conditioning indoor heat exchange unit appearing to have a large heat exchange area, but in reality, the effective heat exchange area utilization rate is low, while also increasing material costs and wind resistance and noise. This embodiment proposes a second important utility model concept: removing the first row of coils in the existing design, retaining only the second and third rows of coils, and reserving a coil-free area of ​​a specific width on the windward side of the evaporator's X-axis thickness direction. The specific technical solution is as follows: The total thickness of the indoor heat exchange unit of the parking air conditioner along the X-axis is defined as D, and it is divided into the windward blank area X1 section and the coil arrangement area X2 section. The width of the X1 section is 1 / 4 to 1 / 2 of D, and the width of the X2 section is 1 / 2 to 3 / 4 of D. Preferably, the width of the X1 section is 1 / 3 of D.

[0019] It is understandable that the width of X1 segment being 1 / 4 of D corresponds to the existing technology of evaporators having four rows of coils. According to the utility model concept of this embodiment, the first row of coils can be removed, and the width of the blank area X1 on the windward side corresponding to the first row of coils is 1 / 4 of D; of course, two rows of coils can also be removed, in which case the width of the blank area X1 on the windward side is 1 / 2 of D.

[0020] After the improvement, the parking air conditioning indoor heat exchange unit only has multiple sets of coils arranged in parallel along the X-axis direction within the X2 section, such as... Figure 1 The second and third columns of coils are in the section, while no coils are installed in the X1 section. The blank area of ​​section X1 and the shielding area of ​​the water receiving trough windward baffle form a matching structure. By leaving blank areas, the resistance of airflow before passing through the coil is reduced, and the uniformity of air intake in the lower part of the evaporator is improved.

[0021] A further preferred approach is to further increase the effective heat exchange area based on the aforementioned "removal of the first row of coils and reservation of a blank area on the windward side". At the same time, considering both performance and cost, the evaporator fin structure is optimized, reducing the fin spacing from 1.4mm to 1.2mm in the existing technology. By increasing the fin arrangement density, the heat exchange area loss caused by removing the first row of coils is compensated. Since the fins are made of aluminum, while the removed first row of coils is made of copper, and the price of copper is much higher than that of aluminum, even with the increase in the amount of fins, the overall material cost of the evaporator is still lower than that of the conventional three-row coil scheme, achieving the dual effect of replenishing the heat exchange area and further reducing costs. Combining the aforementioned cross-intake and exhaust arrangement of the two independent refrigerant branches, each of the second and third coil rows contains pipes for branch A and branch B, with the two branches arranged alternately within each coil row. Therefore, the technical problems of insufficient air intake and temperature gradient between the upper and lower parts of the evaporator are comprehensively solved.

[0022] Furthermore, the existing evaporator does not require a core structural reconstruction. The original horizontal pipe channel 30 can still be used, continuing the original horizontal pipe channel of the evaporator. That is, along the Z-axis, after removing the first row of coils, only the horizontal channel corresponding to the original first row is left empty. The second and third rows of coils still use the original channels and fin hole positions, without the need to adjust the channel size or add a new fixing structure. For branches A and B, the adjustment of the "top in, bottom out" branch A and "bottom in, top out" branch B is achieved only by changing the vertical connection method of the coils in the original horizontal channel. The original evaporator has reserved space for pipe turning in the vertical direction. The turning of branches A and B can be directly achieved by connecting the bends, without the need to add a turning structure or change the fin arrangement.

[0023] Compared to reconstructing the evaporator frame, this technical solution allows for maximum reuse of core components such as the fin forming mold and the frame stamping mold. Only the A / B branch hole positions need to be marked on the fin mold without altering the mold cavity. The production line adjustment cycle is short, and it can be directly integrated into existing mass production lines without requiring production shutdowns. Furthermore, the optimized solution's evaporator dimensions, refrigerant inlet / outlet, and fixing hole positions are completely identical to the original evaporator, allowing for direct replacement of existing parking air conditioner evaporators. Aftermarket modifications require no changes to the air conditioning unit, fan, or other peripheral components, facilitating widespread adoption.

[0024] It should be noted that the specific parameter values ​​given in this embodiment should not be construed as limiting the claims, but are used to illustrate the feasibility of the technical solution given in this embodiment.

[0025] In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, without necessarily requiring or implying any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0026] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An indoor heat exchange unit with a windward blank area, which enables heat exchange between a first fluid and a second fluid, comprising a body including a plurality of fins and a coil assembly inserted in the fins. Multiple fins are spaced apart from each other and arranged in parallel to form a space for the first fluid to flow. A coil assembly comprising a plurality of heat-conducting tubes extending through the plurality of fins and supplying a second fluid in a direction intersecting with the direction of flow of a first fluid. Its features are: The body has a total thickness D along the X-axis direction of the first fluid flow direction, and is divided into a windward blank area X1 section and a coil arrangement area X2 section along the X-axis direction. The width of the windward blank area X1 section is 1 / 4 to 1 / 2 of the total thickness D, and the width of the coil arrangement area X2 section is 1 / 2 to 3 / 4 of the total thickness D.

2. The indoor heat exchange unit with a windward side blank area according to claim 1, characterized in that, The width of the windward blank area X1 section is 1 / 3 of the total thickness D, and the width of the coil arrangement area X2 section is 2 / 3 of the total thickness D.

3. The indoor heat exchange unit with a windward side blank area according to claim 1, characterized in that, Within the X2 section of the coil arrangement area, at least two rows of coils are arranged along the X-axis. Each row contains pipes for branch A and branch B, and the two branches are arranged alternately within each row of coils.

4. The indoor heat exchange unit with a windward side blank area according to claim 1, characterized in that, Multiple fins are spaced apart from each other, with the spacing being 1.2-1.4 mm.

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