Heat exchangers, flow path control methods for heat exchangers, readable storage media, and air conditioners

Abstract

This invention discloses a heat exchanger, a flow path control method for the heat exchanger, a readable storage medium, and an air conditioner. The heat exchanger includes a liquid collection pipe, a gas collection pipe, a gas-liquid separator, a separable module, a variable flow path module, and a fourth control valve. The gas end of the gas-liquid separator is connected to the gas collection pipe via a first pipe. The two ends of the separable module are connected to a liquid end of the gas-liquid separator and the liquid collection pipe via a second pipe and a third pipe, respectively. The two ends of the first heat exchange tube group in the variable flow path module are connected to the liquid collection pipe and another liquid end via a fourth pipe and a fifth pipe, respectively. A first solenoid valve is located on the fourth pipe, and a second solenoid valve is located on the seventh pipe. The first end of the third solenoid valve is connected to the end of the first solenoid valve furthest from the liquid collection pipe, and its second end is connected to the end of the second solenoid valve furthest from the other liquid end. The fourth control valve is located on the first pipe. This invention's technical solution can switch between different numbers of heat exchange flow paths between different operating modes and improve heat exchange efficiency.

Description

Technical Field

[0001] This invention relates to the field of heat exchanger technology, and particularly to a heat exchanger, a flow path control method for the heat exchanger, a readable storage medium, and an air conditioner using the heat exchanger. Background Technology

[0002] For existing heat pump air conditioner heat exchangers, the flow path is the same under various operating modes including cooling, heating, and different frequencies. However, numerous studies have shown that the optimal flow path for indoor and outdoor heat exchangers differs under these conditions. When the heat exchanger acts as a condenser, its pressure loss is relatively small, requiring fewer branch paths to increase refrigerant velocity and thus the heat transfer coefficient. When the heat exchanger acts as an evaporator, during medium- to high-frequency operation, the decrease in the logarithmic mean temperature difference caused by pressure loss has a dominant impact on heat transfer, compared to the effect of flow velocity on the heat transfer coefficient. In this case, more branch paths are needed to increase heat transfer. Consequently, it becomes impossible to adjust the heat exchanger flow path based on actual operating conditions for the same heat exchanger.

[0003] Existing technologies also include air conditioning heat exchangers that change the flow path during evaporation / condensation modes. However, existing heat exchangers are highly specific and have low modularity, making them difficult to adapt to large-capacity air conditioners with large heat exchange areas. Furthermore, during the evaporation process, the gaseous refrigerant still degrades the evaporation heat transfer coefficient, limiting the performance of heat exchangers and heat pumps (hot air blowers, heat pump water heaters). Summary of the Invention

[0004] The main objective of this invention is to propose a heat exchanger that aims to improve the problem of deterioration of the heat transfer coefficient by gaseous refrigerants and enhance the heat exchange effect.

[0005] To achieve the above objectives, the heat exchanger proposed in this invention includes:

[0006] Collection tube;

[0007] Gas collection tube;

[0008] A gas-liquid separator, comprising two liquid ends and one gas end, wherein the gas end is connected to the gas collecting pipe via a first pipeline;

[0009] A separable module, one end of which is connected to the liquid end of the gas-liquid separator via a second pipeline, and the other end of which is connected to the liquid collection pipe via a third pipeline;

[0010] A variable flow path module, comprising: a plurality of parallel first heat exchange tube groups, a plurality of parallel second heat exchange tube groups, a first solenoid valve, a second solenoid valve, and a third solenoid valve;

[0011] One end of the first heat exchange tube assembly is connected to the gas collecting pipe through the fourth pipe, and the other end is connected to the other liquid end through the fifth pipe; one end of the second heat exchange tube assembly is connected to the gas collecting pipe through the sixth pipe, and the other end is connected to the other liquid end through the seventh pipe.

[0012] The first solenoid valve is located in the fifth pipeline, and the second solenoid valve is located in the sixth pipeline; one end of the third solenoid valve is connected to the end of the first solenoid valve away from the gas collecting pipe, and the other end is connected to the end of the second solenoid valve away from the other liquid end; and

[0013] A fourth control valve is located on the first pipeline.

[0014] Optionally, the separable module includes multiple first separation flow paths, which are connected in parallel.

[0015] Optionally, the number of flow paths in the separable module is less than the maximum number of flow paths in the variable flow path module.

[0016] Optionally, the number of the first heat exchange tube group and the number of the second heat exchange tube group are equal, and a third solenoid valve is provided. The end of each first heat exchange tube group near the liquid collecting pipe is connected to one end of the third solenoid valve; the end of each second heat exchange tube group near the gas collecting pipe is connected to the other end of the third solenoid valve.

[0017] Optionally, the fourth control valve is a one-way valve, and the one-way valve is opened from the gas end to the gas collecting pipe.

[0018] Alternatively, the fourth control valve may be an electronic expansion valve.

[0019] Optionally, the heat exchanger further includes a common heat exchange tube assembly, one end of which is connected to the fourth pipeline and the other end of which is connected to the seventh pipeline.

[0020] The present invention also proposes a flow path control method based on the above-mentioned heat exchanger, wherein the heat exchanger is applied in a refrigeration system, and the flow path control method includes:

[0021] Obtain the operating mode of the heat exchanger and the load mode of the refrigeration system;

[0022] When the operating mode is evaporation mode, the fourth control valve is opened.

[0023] When the operating mode is condensation mode, the fourth control valve is closed.

[0024] When the load mode is the first load mode, the variable flow path module adopts the full flow path mode, that is, it controls the first solenoid valve and the second solenoid valve to be turned on, and controls the third solenoid valve to be turned off;

[0025] When the load mode is the second load mode, the variable flow path module adopts a half flow path mode, that is, it controls the first solenoid valve and the second solenoid valve to close and controls the third solenoid valve to open, wherein the first load is greater than the second load.

[0026] Optionally, the refrigeration system further includes a compressor, and the specific steps for obtaining the operating mode of the heat exchanger and the load mode of the refrigeration system include:

[0027] When the heat exchanger is in condensing mode, obtain the outdoor temperature T4 and the compressor operating frequency F1;

[0028] When the outdoor temperature T4 is greater than or equal to the first preset value a; or when the outdoor temperature is less than the first preset value a but greater than the second preset value b, and the compressor frequency F1 ≥ k*(Fmax+Fmin); or when the outdoor temperature is less than the second preset value b, and the compressor frequency F2 ≥ m*(Fmax+Fmin), the refrigeration system is set to the first load mode.

[0029] When the outdoor temperature T4 is less than the first preset value a and greater than or equal to the second preset value b, and the compressor frequency F1 < k*(Fmax+Fmin); or, when the outdoor temperature is less than the second preset value b, and the compressor frequency F2 < m*(Fmax+Fmin), the refrigeration system is set to the second load mode.

[0030] Where a is greater than b, k ranges from 1 / 3 to 5 / 8, m ranges from 5 / 8 to 7 / 8, Fmax is the maximum operating frequency of the compressor, and Fmin is the minimum operating frequency of the compressor.

[0031] Optionally, the range of the first preset value a is 26℃~35℃, and the range of the second preset value b is 10℃~25℃.

[0032] Optionally, when the fourth control valve is an electronic expansion valve, the flow path control method for the heat exchanger further includes:

[0033] Obtain the target operating frequency Fr of the refrigeration system;

[0034] Determine the magnitude of the target operating frequency Fr and the third preset value c;

[0035] If Fr≤c, the initial opening of the electronic expansion valve is set to the first opening A, and the holding time is t1; if Fr>c, the initial opening of the electronic expansion valve is set to the second opening B, and the holding time is t2.

[0036] Where c = l * (Fmax + Fmin), l ranges from 0.45 to 0.75, A is less than B, Fmax is the maximum operating frequency of the compressor, and Fmin is the minimum operating frequency of the compressor;

[0037] After initialization, the coil temperature and suction temperature of the condenser are detected every first preset time interval;

[0038] Determine the difference between the coil temperature and the suction temperature of the heat exchanger, and adjust the opening value of the electronic expansion valve according to the magnitude of the difference.

[0039] Optionally, the step of determining the difference between the coil temperature and the suction temperature of the heat exchanger, and adjusting the opening adjustment value of the electronic expansion valve according to the magnitude of the difference, specifically includes:

[0040] Let the difference be ∆T. If ∆T < -1.5, then the opening degree of the electronic expansion valve is increased by a first opening degree value E; if -1.5 < ∆T ≤ -0.5, then the opening degree of the electronic expansion valve is increased by a second opening degree value F.

[0041] If -0.5 < ∆T ≤ 0.5, then the opening degree of the electronic expansion valve remains unchanged;

[0042] If 0.5 < ∆T ≤ 1.5, then the opening degree of the electronic expansion valve is reduced by the third opening value - (F+1).

[0043] If ∆T>1.5, then the opening degree of the electronic expansion valve is reduced by the fourth opening degree value - (E+1).

[0044] Where E > F.

[0045] Optionally, the first preset time ranges from 30s to 300s, F ranges from 2P to 15P, and E ranges from 4P to 30P.

[0046] The present invention also proposes a readable storage medium storing a flow path control program for a heat exchanger, wherein when the flow path control program for the heat exchanger is executed by a processor, the flow path control program for the heat exchanger implements the steps of the flow path control method for the heat exchanger described above.

[0047] The present invention also proposes an air conditioner comprising any one of the heat exchangers described above.

[0048] Optionally, the air conditioner includes an outdoor unit, and the heat exchanger is disposed inside the outdoor unit.

[0049] In this invention, when the heat exchanger is used as an evaporator, the liquid phase change working fluid enters from the liquid collection pipe. It first undergoes preliminary evaporation through a separable module, then enters a gas-liquid separator for gas-liquid separation via the liquid end. The separated gas enters the first pipeline via the gas end, and after passing through the fourth control valve, it enters the gas collection pipe. The liquid portion enters the variable flow path module via another liquid end. This allows for timely separation of the gas portion after preliminary heat exchange, resulting in a higher heat transfer coefficient for the subsequent liquid portion and effectively enhancing the heat exchanger's heating effect. After entering the variable flow path module, the fluid splits into two paths. By activating the first solenoid valve, it flows along the fifth and seventh pipelines to the first and second heat exchange tube groups, respectively. After heat exchange in the first heat exchange tube group, the gaseous phase change working fluid flows to the fourth pipeline, and after heat exchange in the second heat exchange tube group, it flows to the sixth pipeline. By activating the second solenoid valve, the phase change working fluid can flow out from both the third and fourth pipelines and converge into the gas collection pipe. In this state, the number of flow paths for the phase change working fluid is the sum of the first and second heat exchanger tube groups, meaning there are more flow paths. This increases the heat exchange capacity in evaporation mode, further achieving a better heat exchange effect. When the heat exchanger is used as a condenser, the gaseous phase change working fluid enters from the gas collecting pipe. By opening the third solenoid valve and closing the first and second solenoid valves, the first and second heat exchanger tube groups are connected in series. The phase change working fluid flowing out of the gas collecting pipe flows to the gas-liquid separator after heat exchange with the first and second heat exchanger tube groups. This reduces the number of flow paths in condensation mode, increases the flow rate of the phase change working fluid, and thus increases the heat transfer coefficient. Furthermore, after passing through the separable module, it can achieve further recooling and subcooling, increasing heat exchange efficiency and again achieving a better heat exchange effect. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0051] Figure 1 This is a schematic diagram of the structure of the heat exchanger of the present invention when it is used as an evaporator in one embodiment;

[0052] Figure 2 for Figure 1 The diagram shows the structure of the heat exchanger when it is used as a condenser.

[0053] Figure 3 This is a schematic diagram of another embodiment of the heat exchanger of the present invention;

[0054] Figure 4 This is a schematic diagram of another embodiment of the heat exchanger of the present invention;

[0055] Figure 5 This is a schematic diagram of the flow path structure of the heat exchanger of the present invention when it is used as an evaporator and is in the first load mode (high load mode);

[0056] Figure 6 This is a schematic diagram of the flow path structure when the heat exchanger of the present invention is used as an evaporator and is in the second load mode (low load mode);

[0057] Figure 7 This is a schematic diagram of the flow path structure of the heat exchanger of the present invention when it is used as a condenser and is in the first load mode (high load mode).

[0058] Figure 8 This is a schematic diagram of the flow path structure of the heat exchanger of the present invention when it is used as a condenser and is in the second load mode (low load mode).

[0059] Explanation of icon numbers:

[0060]

[0061] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0062] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0063] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0064] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0065] This invention proposes a heat exchanger.

[0066] In embodiments of the present invention, such as Figure 1 and Figure 2 As shown, the heat exchanger proposed in this invention includes a liquid collecting pipe 100, a gas collecting pipe 200, a gas-liquid separator 700, a separable module 800, a variable flow path module, and a fourth control valve 540. The gas-liquid separator 700 includes two liquid ends (702, 703) and a gas end 701. The gas end 701 is connected to the gas collecting pipe 200 through a first pipe 610. One end of the separable module 800 is connected to one of the liquid ends 702 of the gas-liquid separator 700 through a second pipe 620, and the other end is connected to the liquid collecting pipe 100 through a third pipe 630.

[0067] The variable flow path module includes several parallel first heat exchange tube groups 300, several parallel second heat exchange tube groups 400, a first solenoid valve 510, a second solenoid valve 520, and a third solenoid valve 530; one end of the first heat exchange tube group 300 is connected to the gas collecting pipe 200 through a fourth pipe 640, and the other end is connected to the other liquid end 703 through a fifth pipe 650; one end of the second heat exchange tube group 400 is connected to the gas collecting pipe 200 through a sixth pipe 660, and the other end is connected to the other liquid end 703 through a seventh pipe 670; the first solenoid valve 510 is located on the fifth pipe 650, and the second solenoid valve 520 is located on the sixth pipe 660; one end of the third solenoid valve 530 is connected to the end of the first solenoid valve 510 away from the gas collecting pipe 200, and the other end is connected to the end of the second solenoid valve 520 away from the other liquid end 703; the fourth control valve 540 is located on the first pipe 610.

[0068] It should be noted that the phase change working fluid in the heat exchanger of the present invention can flow either from the liquid collecting pipe 100 to the gas collecting pipe 200, or from the gas collecting pipe 200 to the liquid collecting pipe 100. Therefore, the heat exchanger of the present invention can be adapted to air conditioners that have both cooling and heating functions. For example, when the air conditioner is in heating mode, it functions as an evaporator in the outdoor unit; or when the air conditioner is in cooling mode, it functions as a condenser in the outdoor unit. Of course, the heat exchanger can also be used in heat pump systems or other systems that perform cooling or heating.

[0069] For the refrigerant evaporation process inside a circular tube, the refrigerant flow pattern, with increasing dryness, is as follows: single-phase liquid flow, bubbly flow, slug flow, annular flow, mist flow, and single-phase gas flow. In the bubbly, slug, and annular flow regions, as the refrigerant dryness increases, the heat transfer coefficient on the inner surface of the tube increases due to the increase in the average flow velocity inside the tube. However, in the mist flow region, due to excessive refrigerant dryness, the liquid film on the inner surface of the tube is destroyed, leading to deteriorated heat transfer and a sharp decrease in the heat transfer coefficient, which greatly affects the heat exchange performance of the evaporator. Applying gas bypass evaporation technology can effectively reduce the area of ​​the mist flow region, thereby increasing the effective heat exchange area of ​​the heat exchanger. In the technical solution of this invention, the phase separation evaporator technology can reduce the average flow velocity of the refrigerant, thereby reducing the refrigerant-side resistance loss and improving the overall performance of the heat exchanger. Therefore, when the heat exchanger is in evaporation mode, a portion of the phase change refrigerant can be evaporated first through the separable module 800. Then, at the point where heat exchange efficiency deteriorates, the gaseous refrigerant after heat exchange is separated by the gas-liquid separator 700. The remaining liquid refrigerant continues to evaporate, thereby improving the problem of deteriorated evaporation heat transfer coefficient of the gaseous refrigerant and improving heat exchange effect and efficiency. That is, during heating, gaseous refrigerant can be extracted to improve the evaporation heat transfer coefficient, thereby improving the overall heat exchange efficiency. At the same time, the heat exchanger can achieve the effect of switching different numbers of flow paths when in different modes. It is understandable that when the heat exchanger is operating under high load, the decrease in logarithmic mean temperature difference caused by pressure loss has a dominant impact on the heat exchange capacity compared to the influence of flow rate on the heat transfer coefficient. In this case, we would like to use more flow paths to increase the heat exchange capacity. When the heat exchanger is in high-load operation mode, the first solenoid valve 510 and the second solenoid valve 520 are turned on, and the third solenoid valve 530 is turned off; when the heat exchanger is in low-load operation mode, the first solenoid valve 510 and the second solenoid valve 520 are turned off, and the third solenoid valve 530 is turned on.

[0070] Specifically, when the heat exchanger functions as an evaporator, the first solenoid valve 510 and the second solenoid valve 520 are both turned on, the third solenoid valve 530 is turned off, and the fourth control valve 540 is also turned on. The two ends of the first heat exchange tube assembly 300 are connected to the gas collecting pipe 200 and the gas-liquid separator 700 via the fourth pipe 640 and the fifth pipe 650, respectively. The two ends of the second heat exchange tube assembly 400 are connected to the gas collecting pipe 200 and the gas-liquid separator 700 via the sixth pipe 660 and the seventh pipe 670, respectively. If the liquid level is 00, the phase change working fluid entering from the liquid collection pipe 100 will first pass through the separable module 800. After preliminary evaporation and heat exchange, it will enter the gas-liquid separator 700. The gaseous working fluid will flow from the gas end 701 to the gas collection pipe 200, while the remaining liquid working fluid will flow in two separate paths. One path will flow sequentially through the fifth pipe 650 (including the first solenoid valve 510) and the first heat exchange tube group 300; the other path will flow through the seventh pipe 670 and the second heat exchange tube group 400. Then, after simultaneous heat exchange in the first heat exchange tube group 300 and the second heat exchange tube group 400, it will be converted into a gaseous state and will converge into the gas collection pipe 200 via the fourth pipe 640 and the sixth pipe 660 respectively. Therefore, when the heat exchanger is used as an evaporator, the gaseous working fluid after heat exchange can be separated in a timely manner, reducing the deterioration of the heat exchange performance of the liquid working fluid. When the number of the first heat exchange tube group 300 and the second heat exchange tube group 400 are defined as A and B respectively, the phase change working fluid can flow through (A+B) flow paths simultaneously in the variable flow path module. Here, the total number of the first heat exchange tube group 300 and the second heat exchange tube group 400 is at least 4, that is, the phase change working fluid flows through at least 4 flow paths simultaneously in the variable flow path module.

[0071] When the heat exchanger is used as a condenser, the flow rate of the phase change working fluid has a dominant effect on the heat exchange capacity. In this case, we want to use fewer flow paths to increase the heat transfer coefficient. Specifically, when the heat exchanger is used as a condenser, by shutting off the first solenoid valve 510 and the second solenoid valve 520, opening the third solenoid valve 530, and shutting off the fourth control valve 540, the high-temperature and high-pressure gaseous phase change working fluid entering from the gas collecting pipe 200 will only flow into the first heat exchange tube group 300 through the fourth pipe 640 for heat exchange, so that the phase change working fluid condenses into a liquid state. Next, since the first solenoid valve 510 on the fifth pipe 650, which is connected to the first heat exchange tube group 300, is in the closed state, the phase change working fluid will not flow from the fifth pipe 650 to the gas-liquid separator 700. Instead, it will enter the second heat exchange tube group 400 for further heat exchange, becoming more liquid phase change working fluid. Then, it will flow from the second heat exchange tube group 400 to the seventh pipe 670, and from the seventh pipe 670 to the gas-liquid separator 700. From the second heat exchange tube group 400, it will sequentially enter the fifth pipe 650 and the outlet pipe, and finally flow out from the outlet pipe. Therefore, when the heat exchanger is used as a condenser, and the number of the first heat exchange tube group 300 and the second heat exchange tube group 400 is defined as A and B respectively, the phase change working fluid can first flow simultaneously through the A main heat exchange path, and then simultaneously through the B subcooling path. It is understood that the number of the first heat exchange tube group 300 and the second heat exchange tube group 400 can be the same. When the number of the first heat exchange tube group 300 and the second heat exchange tube group 400 is the same, the number of heat exchange flow paths of the heat exchanger in the technical solution of the present invention when it is used as an evaporator is twice the number of heat exchange flow paths of the heat exchanger when it is used as a condenser.

[0072] This invention achieves the flow of phase change working fluid with different numbers of flow paths in different operating modes simply by adding three solenoid valves to the heat exchanger. By controlling the opening and closing of these three valves, the heat exchanger can have more flow paths when operating as an evaporator, thereby increasing heat exchange capacity and improving heat exchange performance during evaporation; and fewer flow paths when operating as a condenser, thereby increasing the flow rate of the phase change working fluid and improving heat exchange performance during condensation. Thus, the heat exchanger can adapt to different modes and maintain good heat exchange performance in all modes.

[0073] Furthermore, the first heat exchange tube group 300 and the second heat exchange tube group 400 in the heat exchanger of the present invention are both modular, which can adapt to large-capacity air conditioners with large heat exchange areas, as well as small-capacity air conditioners with small heat exchange areas, or air conditioners that focus on dehumidification, etc. That is, when a large heat exchange area is required under high-load mode, the number of the first heat exchange tube group 300 and / or the second heat exchange tube group 400 can be increased in parallel without adding other solenoid valve groups to achieve the effect of different heat exchange flow paths in different operating modes. Therefore, the heat exchanger of the present invention has strong modularity and versatility, simple control, low cost, can adapt to various different modes, and the number of the first heat exchange tube group 300 and / or the second heat exchange tube group 400 can be flexibly increased.

[0074] In this invention, when the heat exchanger is used as an evaporator, the liquid phase change working fluid enters from the liquid collection pipe 100. It first undergoes preliminary evaporation through the separable module 800, and then enters the gas-liquid separator 700 through the liquid end 703 for gas-liquid separation. The separated gas enters the first pipeline 610 through the gas end 701, and then enters the gas collection pipe 200 after passing through the fourth control valve 540. The liquid part enters the variable flow path module through another liquid end 702. In this way, after the preliminary heat exchange, the gas part can be separated out in time, resulting in a higher heat transfer coefficient for the subsequent liquid part and effectively enhancing the heating effect of the heat exchanger. After entering the variable flow path module, the flow splits into two paths. By activating the first solenoid valve 510, the fluid flows along the fifth pipe 650 and the seventh pipe 670 to the first heat exchange tube group 300 and the second heat exchange tube group 400, respectively. After heat exchange in the first heat exchange tube group 300, the gaseous phase change working fluid flows to the fourth pipe 640, and after heat exchange in the second heat exchange tube group 400, it flows to the sixth pipe 660. By activating the second solenoid valve 520, the phase change working fluid can flow out from both the third pipe 630 and the fourth pipe 640, and converge into the gas collecting pipe 200. In this state, the number of flow paths for the phase change working fluid is the sum of the number of flow paths in the first heat exchange tube group 300 and the second heat exchange tube group 400, i.e., a larger number of flow paths, thereby increasing the heat exchange capacity in evaporation mode and further achieving a better heat exchange effect. When the heat exchanger is used as a condenser, the gaseous phase change working fluid enters from the gas collecting pipe 200. By opening the third solenoid valve 530 and closing the first solenoid valve 510 and the second solenoid valve 520, the first heat exchange tube group 300 and the second heat exchange tube group 400 are connected in series. The phase change working fluid flowing out of the gas collecting pipe 200 flows to the liquid collecting pipe 100 after heat exchange with the first heat exchange tube group 300 and the second heat exchange tube group 400. This reduces the number of flow paths and increases the flow rate of the phase change working fluid in condensation mode, thereby increasing the heat transfer coefficient and achieving a better heat exchange effect.

[0075] Optionally, the separable module 800 includes a plurality of first separation flow paths 801, which are arranged in parallel.

[0076] In this embodiment, specifically, a separable module 800 is provided at the end of the liquid collection pipe 100 away from the first heat exchange tube group 300 and the second heat exchange tube group 400. The separable module 800 includes two parallel first separation flow paths 801. When the heat exchanger is used as an evaporator, the working fluid flow rate is reduced by increasing the flow path. After passing through the two first separation flow paths 801, the phase change working fluid enters the gas-liquid separator 700, so that part of the evaporated gas can be separated and enter the gas collection pipe 200 through the fourth control valve 540, while the remaining liquid continues to enter the variable flow path module for further evaporation. When the heat exchanger is used as a condenser, the phase change working fluid can undergo heat exchange again through the two first separation flow paths 801 after heat exchange in the first heat exchange tube group 300 and the second heat exchange tube group 400, and then be re-cooled, which can further improve the heat exchange efficiency.

[0077] Of course, in other embodiments, two or more first separation flow paths 801 can be arranged in parallel. Alternatively, in another embodiment, after the phase change working fluid passes through two first separation flow paths 801, it continues to pass through a second separation flow path 802 for heat exchange, i.e., it undergoes subcooling treatment, and then enters the liquid collection pipe 100. This can further improve heat exchange efficiency and heat exchange effect, and ensure that the phase change working fluid receives sufficient heat exchange, thereby improving heat exchange efficiency.

[0078] Optionally, the number of flow paths in the separable module 800 is less than the maximum number of flow paths in the variable flow path module.

[0079] In this embodiment, the separable module 800, serving as a module to improve the heat transfer coefficient at the deterioration point of the gaseous working fluid, should not have an excessively large number of parallel flow paths, which cannot exceed the number of flow paths in the variable flow path module, which serves as the primary heat exchange function. The total number of flow paths in the separable module 800 is less than the maximum number of flow paths in the variable flow path module. For example, the separable module 800 includes two first separation flow paths 801, which is less than the maximum number of flow paths (4) in the variable flow path module when it has two first heat exchange tube groups 300 and two second heat exchange tube groups 400. However, when the variable flow path module has a maximum of 5 or 6 flow paths, the number of flow paths in the separable module 800 can be 3 or 4, etc.

[0080] Of course, the length of a single flow path in the separable module 800 should not be too large, and cannot exceed the length of a single flow path in the variable flow path module, which serves as the main heat exchange function. Conversely, its length should not be too small, otherwise it will not effectively reduce the flow velocity and improve the heat transfer coefficient. The length of a single flow path in the separable module 800 is 0.15 to 0.55 times that of the variable flow path module, for example, 0.15, 0.2, 0.3, 0.4, or 0.5 times, which allows it to work in conjunction with the variable flow path module to achieve better heat exchange performance. Here, the optional length of a single flow path in the separable module 800 is 0.5 times that of the variable flow path module.

[0081] Optionally, the number of the first heat exchange tube group 300 and the second heat exchange tube group 400 are equal, and the third solenoid valve 530 is provided. The end of each first heat exchange tube group 300 near the liquid collecting pipe 100 is connected to one end of the third solenoid valve 530; the end of each second heat exchange tube group 400 near the gas collecting pipe 200 is connected to the other end of the third solenoid valve 530.

[0082] In this embodiment, by setting at least two first heat exchange tube groups 300, and by arranging at least two first heat exchange tube groups 300 in parallel, the number of flow paths when the heat exchanger is used as an evaporator can be increased, and the flow path length when the heat exchanger is used as a condenser can also be increased. It is understood that the number of first heat exchange tube groups 300 and the number of second heat exchange tube groups 400 can be the same or different. Here, when the number of first heat exchange tube groups 300 and second heat exchange tube groups 400 is the same and both are set to N, the number of flow paths when the heat exchanger is used as an evaporator is 2N, and the number of flow paths when the heat exchanger is used as a condenser is N, and the flow path length of each flow path is the same, which is beneficial to improving heat exchange efficiency and uniformity. Here, N is an integer, for example, it can be 1, 2, 3, 4, or 5, etc. In this case, the separable module 800 includes two first separation flow paths 801, which is less than the maximum number of flow paths of the variable flow path module.

[0083] By setting a third solenoid valve 530, the series and parallel operation of the first heat exchanger tube group 300 and the second heat exchanger tube group 400 can be controlled simply by opening and closing this third solenoid valve 530, which is simple and convenient and reduces the setup of the control program. Specifically, when the third solenoid valve 530 is opened, the module consisting of all parallel first heat exchanger tube groups 300 and the module consisting of all parallel second heat exchanger tube groups 400 can be connected in series, thereby reducing the number of flow paths for the phase change working fluid, which can be used when the heat exchanger is used as a condenser. When the third solenoid valve 530 is closed, all first heat exchanger tube groups 300 and all second heat exchanger tube groups 400 can be connected in parallel, thereby increasing the number of flow paths for the phase change working fluid, which can be used when the heat exchanger is used as an evaporator.

[0084] Of course, in other embodiments, at least two third solenoid valves 530 may be provided. Each third solenoid valve 530 is connected between a first heat exchange tube group 300 and a second heat exchange tube group 400, and when the heat exchanger is used as a condenser, the first heat exchange tube group 300 and the second heat exchange tube group 400 are connected in series. Then each third solenoid valve 530 controls a module composed of a first heat exchange tube group 300 and a second heat exchange tube group 400, thereby making the control of the number of flow paths of the entire heat exchanger more flexible, and also making the path of the phase change working fluid from the first heat exchange tube group 300 to the second heat exchange tube group 400 (or from the second heat exchange tube group 400 to the first heat exchange tube group 300) shorter. It can also avoid the situation where the entire heat exchanger cannot work when one of the third solenoid valves 530 is damaged.

[0085] Optionally, the fourth control valve 540 is a one-way valve, and the direction of conduction of the one-way valve is from the gas end 701 to the gas collection pipe 200; or, the fourth control valve 540 is an electronic expansion valve.

[0086] Combination Figure 1 and Figure 2 In this embodiment, the fourth control valve 540 is a one-way valve, which can only be opened in one flow direction and cannot be opened in the opposite direction. Therefore, by setting the fourth control valve 540 as a one-way valve, the procedure of setting other control units to control the opening and closing of the fourth control valve 540 can be eliminated. When the heat exchanger is used as an evaporator, the one-way valve can be opened, so that the gas in the gas-liquid separator 700 can enter the gas collecting pipe 200 through the one-way valve and the first pipeline 610. Of course, when the heat exchanger is used as a condenser, the one-way valve is not open. At this time, the second solenoid valve 520 is also not open. The phase change working fluid entering through the gas collecting pipe 200 can only flow to the fourth pipe 640 and enter the first heat exchange tube group 300. Moreover, when the phase change working fluid enters the gas-liquid separator 700 after passing through the variable flow path module, the pressure at the end of the one-way valve near the gas-liquid separator 700 is lower than that at the end near the gas collecting pipe 200. Therefore, the gas-liquid separator 700 does not work. Thus, the fluid enters the separable module 800 from the liquid end 702 at the lower end for recooling or subcooling, further improving the heat exchange effect.

[0087] Please refer to Figure 3In other embodiments, the fourth control valve 540 can also be an electronic expansion valve or a capillary tube. When the heat exchanger functions as an evaporator, the electronic expansion valve is activated and adjusted to a suitable opening degree, allowing the gaseous working fluid separated from the gas-liquid separator 700 to undergo appropriate pressure reduction before entering the gas collecting pipe 200 and then returning to the compressor 2000 for intake. When the heat exchanger functions as a condenser, the electronic expansion valve opening degree is set to zero. That is, the gas collecting pipe 200 does not enter the gas-liquid separator 700 through the first pipe 610, but instead undergoes heat exchange through the variable flow path module before flowing to the gas-liquid separator 700. At this time, the pressure of the phase change working fluid decreases after heat exchange, becoming less than the working fluid pressure exiting the gas collecting pipe 200. Therefore, it cannot pass through the electronic expansion valve for direct recooling or subcooling before entering the liquid collecting pipe 100.

[0088] Please combine Figure 4 Optionally, the heat exchanger further includes a common heat exchange tube assembly 900, one end of which is connected to a fourth pipe 640 and the other end of which is connected to a seventh pipe 670.

[0089] In this embodiment, based on the arrangement of the first solenoid valve 510 located in the fifth pipeline 650 and the second solenoid valve 520 located in the sixth pipeline 660, the heat exchanger also includes a common heat exchange tube assembly 900. One end of the common heat exchange tube assembly 900 is connected to the fourth pipeline 640, and the other end is connected to the seventh pipeline 670. This ensures that the common heat exchange tube assembly 900 is in a constantly flowing state and is not affected by the opening and closing of the first solenoid valve 510, the second solenoid valve 520, etc. That is, regardless of whether the first solenoid valve 510 and / or the second solenoid valve 520 are in the open or closed state, the common heat exchange tube assembly 900 can supply the phase change working fluid, allowing the phase change working fluid to flow from the inlet pipe to the outlet pipe.

[0090] Of course, in another embodiment, when the first solenoid valve 510 is located in the seventh pipeline 670 and the second solenoid valve 520 is located in the fourth pipeline 640, in this embodiment, the heat exchange tube assembly 900 is usually connected to the sixth pipeline 660 at one end and to the fifth pipeline 650 at the other end.

[0091] It is understandable that there can be one, two, or more commonly used heat exchanger tube groups 900. Let M be the number of commonly used heat exchanger tube groups 900, and N be the number of the first heat exchanger tube group 300 and the second heat exchanger tube group 400. Then, when the heat exchanger is used as an evaporator, the number of heat exchanger flow paths through which the phase change working fluid flows is (2N+M); when the heat exchanger is used as a condenser, the number of heat exchanger flow paths through which the phase change working fluid flows is (N+M). The values ​​of N and M can be the same or different, and both N and M are integers, taking values ​​of 1, 2, 3, 4, or 5, etc. Here, while using commonly used heat exchanger tube groups 900, the fourth control valve 540 is selected as an electronic expansion valve.

[0092] Furthermore, a one-way valve can be connected in series with the commonly used heat exchanger tube assembly 900. This one-way valve can control whether the commonly used heat exchanger tube assembly 900 can be supplied with the phase change working fluid. By limiting the conduction direction of the one-way valve to from the end near the liquid collecting pipe 100 to the end near the gas collecting pipe 200, it can be understood that the one-way valve only conducts when the heat exchanger is acting as an evaporator, and does not conduct when the heat exchanger is acting as a condenser. This results in the heat exchanger having more heat exchange flow paths in evaporation mode compared to condensation mode, thereby increasing the heat exchange capacity in evaporation mode due to the increased flow paths, and thus improving the heat exchange effect. It can be understood that in condensation mode, there are fewer heat exchange flow paths, which can increase the flow rate of the phase change working fluid, thereby increasing the heat transfer coefficient and also improving the heat exchange effect.

[0093] Optionally, the first heat exchanger tube group 300 can be a double-row heat exchanger tube group or a single-row heat exchanger tube group; and / or, the second heat exchanger tube group 400 can be a double-row heat exchanger tube group or a single-row heat exchanger tube group. Regardless of whether the first heat exchanger tube group 300 is a double-row or single-row heat exchanger tube group, it has two interconnected ports, each a conduit through which the phase change working fluid enters from one port and exits from the other. It is understood that when the first heat exchanger tube group 300 is a double-row heat exchanger tube group, it can be connected via an intermediate conduit through which the outlet of one of the two single-row heat exchanger tube groups is connected to the inlet of the other. Of course, the type of the second heat exchanger tube group 400 can be the same as or different from that of the first heat exchanger tube group 300, and the second heat exchanger tube group 400 can also be a double-row or single-row heat exchanger tube group.

[0094] The present invention also proposes an air conditioner, which includes a heat exchanger. The specific structure of the heat exchanger is as described in the above embodiments. Since the air conditioner adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0095] Furthermore, the air conditioner can be a split-type air conditioner, comprising an indoor unit and an outdoor unit connected by refrigerant pipes. Specifically, the indoor unit contains a first heat exchange module, and the outdoor unit contains a second heat exchange module. The first heat exchange module, the second heat exchange module, and the compressor 2000 are connected by refrigerant pipes to form a circulation loop. The heat exchanger in this invention can be located inside the indoor unit, serving as the first heat exchange module; or the heat exchanger can also be located inside the outdoor unit, serving as the second heat exchange module.

[0096] The present invention also proposes a flow path control method based on the above-mentioned heat exchanger, wherein the heat exchanger is applied in a refrigeration system, and the flow path control method includes:

[0097] Step S1: Obtain the operating mode of the heat exchanger and the load mode of the refrigeration system;

[0098] Step S2: When the operating mode is evaporation mode, control the fourth control valve 540 to open;

[0099] Step S3: When the operating mode is condensation mode, control the fourth control valve 540 to close;

[0100] Step S4: When the load mode is the first load mode, the variable flow path module adopts the full flow path mode, that is, it controls the first solenoid valve 510 and the second solenoid valve 520 to be turned on, and controls the third solenoid valve 530 to be turned off.

[0101] Step S5: When the load mode is the second load mode, the variable flow path module adopts a half flow path mode, that is, it controls the first solenoid valve 510 and the second solenoid valve 520 to close, and controls the third solenoid valve 530 to open, wherein the first load is greater than the second load.

[0102] In this embodiment, since the fourth control valve 540 controls the gas flow in the gas-liquid separator 700, when the heat exchanger is in evaporation mode, timely gas-liquid separation is required. Therefore, the fourth control valve 540 is opened, allowing the gaseous working fluid to enter the gas collecting pipe 200 through the fourth control valve 540. When the heat exchanger is in condensation mode, gas does not need to enter the gas-liquid separator 700 first, so the fourth control valve 540 is closed, allowing the phase change working fluid to undergo heat exchange and condensation through the variable flow path module. Therefore, it is necessary to obtain the operating mode of the heat exchanger to control the fourth control valve 540, thereby improving the heat transfer coefficient.

[0103] Understandably, regardless of whether the heat exchanger functions as an evaporator or a condenser, it has a first load mode and a second load mode, with the first load being greater than the second load. In the first load mode, the heat exchanger requires a larger number of heat exchange flow paths, thereby increasing the heat exchange capacity under higher load conditions and achieving better heat exchange performance. In the second load mode, however, fewer flow paths are needed, resulting in better flow rates and improved heat exchange performance. Therefore, it is necessary to control the first solenoid valve 510, the second solenoid valve 520, and the third solenoid valve 530 according to the load mode of the refrigeration system to achieve optimal heat exchange performance.

[0104] Please combine Figure 5 When the heat exchanger is used as an evaporator and is in the first load mode, the variable flow path adopts a full flow path mode. The first solenoid valve 510 and the second solenoid valve 520 are opened, and the third solenoid valve 530 is closed. The phase change working fluid can then flow in through the liquid collection pipe 100, pass through the separable module 800, and enter the gas-liquid separator 700. Part of the evaporated gas is separated and flows out through the fourth control valve 540. The liquid portion flows into the first heat exchange tube group 300 through the fifth pipe 650 and the first solenoid valve 510, and into the second heat exchange tube group 400 through the seventh pipe 670. The phase change working fluid flowing out of the first heat exchange tube group 300 flows into the gas collection pipe 200 through the fourth pipe 640, and the phase change working fluid flowing out of the second heat exchange tube group 400 flows into the gas collection pipe 200 through the sixth pipe 660 and the second solenoid valve 520.

[0105] Please refer to Figure 7 When the heat exchanger functions as a condenser and is in the first load mode, the phase change working fluid flows in through the gas collecting pipe 200, and then flows into the first heat exchange tube group 300 via the fourth pipe 640, and into the second heat exchange tube group 400 via the sixth pipe 660 and the second solenoid valve 520. The phase change working fluid flowing out of the first heat exchange tube group 300 flows into the gas-liquid separator 700 via the fifth pipe 650 and the first solenoid valve 510. The phase change working fluid flowing out of the second heat exchange tube group 400 flows into the gas-liquid separator 700 via the seventh pipe 670. In summary, as long as the heat exchanger is in the first load mode, the number of flow paths for the phase change working fluid is the sum of the first heat exchange tube group 300 and the second heat exchange tube group 400. The larger number of heat exchange flow paths increases the heat exchange capacity under higher load operating conditions, achieving a better heat exchange effect.

[0106] Please combine Figure 6When the heat exchanger is used as an evaporator and is in the second load mode, the phase change working fluid flowing out from the liquid collection pipe 100 improves the heat transfer coefficient after passing through the separable module 800 and the gas-liquid separator 700. After heat exchange through the second heat exchange tube group 400 and the first heat exchange tube group 300, it flows to the gas collection pipe 200. This also reduces the number of flow paths by half compared to the first load mode, thus meeting the requirement of increasing the heat transfer coefficient under a smaller load mode and achieving a better heat exchange effect.

[0107] Please refer to Figure 8 When the heat exchanger functions as a condenser and is in the second load mode, the phase change working fluid flowing from the gas collecting pipe 200 exchanges heat with the first heat exchange tube group 300 and the second heat exchange tube group 400 before flowing to the liquid collecting pipe 100. In this case, the number of flow paths is reduced by half compared to the first load mode. Therefore, regardless of whether it's evaporation or condensation mode, when the heat exchanger is in the second load mode, it adopts a semi-flow path mode. By closing the first solenoid valve 510 and the second solenoid valve 520, and only opening the third solenoid valve 530, the first heat exchange tube group 300 and the second heat exchange tube group 400 are connected in series. This reduces the number of flow paths in the low load mode, thereby increasing the flow rate of the phase change working fluid and meeting the requirement of increasing the heat transfer coefficient in the lower load mode, achieving a better heat exchange effect.

[0108] The heat exchanger in this invention achieves a variable number of heat exchange flow paths simply by adjusting the opening and closing of the first solenoid valve 510, the second solenoid valve 520, and the third solenoid valve 530. This allows the heat exchanger to have a corresponding number of heat exchange flow paths under different load modes, ensuring good heat exchange performance in all modes. Furthermore, by adjusting the opening and closing of the fourth control valve 540, the problem of heat transfer coefficient degradation in evaporation mode can be mitigated. The addition of the separable module 800 further reduces the working fluid flow rate, thereby further enhancing the heat exchange effect in conjunction with the multi-flow path mode. In other words, gaseous refrigerant can be extracted during heating, increasing the evaporative heat transfer coefficient and thus improving the overall heat exchange efficiency. In addition, the first heat exchange tube group 300 and the second heat exchange tube group 400 in this invention are modular, so the number of flow paths can be increased arbitrarily. Furthermore, when increasing or decreasing the number of flow paths, it is possible to achieve this without increasing the number of control valves. This results in a variety of heat exchange flow path variations for the heat exchanger, making control simple and cost-effective.

[0109] Please refer to Figure 7 and Figure 8 Optionally, the refrigeration system further includes a compressor 2000, and the specific steps for obtaining the operating mode of the heat exchanger and the load mode of the refrigeration system include:

[0110] Step S11: When the heat exchanger is in condensing mode, obtain the outdoor temperature T4 and the operating frequency F1 of the compressor 2000;

[0111] Step S12: When the outdoor temperature T4 is greater than or equal to the first preset value a; or when the outdoor temperature is less than the first preset value a but greater than the second preset value b, and the frequency F1 of the compressor 2000 is greater than k*(Fmax+Fmin); or when the outdoor temperature is less than the second preset value b, and the frequency F2 of the compressor 2000 is greater than m*(Fmax+Fmin), the refrigeration system is set to the first load mode;

[0112] Step S13: When the outdoor temperature T4 is less than the first preset value a and greater than or equal to the second preset value b, and the frequency F1 of the compressor 2000 is less than k*(Fmax+Fmin); or, when the outdoor temperature is less than the second preset value b, and the frequency F2 of the compressor 2000 is less than m*(Fmax+Fmin), the refrigeration system is set to the second load mode.

[0113] Where a is greater than b, k ranges from 1 / 3 to 5 / 8, m ranges from 5 / 8 to 7 / 8, Fmax is the maximum allowable operating frequency of compressor 2000, and Fmin is the minimum allowable operating frequency of compressor 2000.

[0114] In this embodiment, the heat exchanger is applied to a refrigeration system, such as an air conditioner, water heater, or refrigerator. Taking the application of the heat exchanger to the outdoor unit of an air conditioner as an example, when the heat exchanger acts as a condenser, the air conditioner operates in cooling mode. Higher ambient temperatures indicate a harsher environment, causing the heat exchanger to operate under a higher load. Alternatively, a higher compressor 2000 RPM frequency indicates a greater load, resulting in the heat exchanger operating under a higher load. Conversely, the heat exchanger operates under a lower load. In this invention, if the first load is greater than the second load, it indicates that the first load mode is a higher load mode, and the second load mode is a lower load mode. This invention determines the heat exchanger's mode by simultaneously acquiring the outdoor temperature T4 and the compressor 2000 RPM frequency F1, comprehensively considering both conditions, thus making the mode determination more accurate.

[0115] Specifically, when the outdoor temperature T4 is greater than or equal to a (where 26℃≤a≤35℃, for example, a can be 26℃, 27℃, 28℃, 29℃, 30℃, 31℃, 32℃, 33℃, 34℃ or 35℃, and further, a is preferably recommended to be 33℃), it indicates that the ambient temperature is very high. That is, when the air conditioner is in cooling mode, regardless of whether the compressor 2000's operating frequency is high or low, it indicates that the environmental conditions are very harsh. Therefore, the heat exchanger must be under a large load when it is running, and thus it can be determined that the heat exchanger is in the first load mode. When the outdoor temperature b≤T4<a is obtained (where 10℃≤b≤25℃, for example b can be 10℃, 11℃, 12℃, 13℃, 14℃, 15℃, 16℃, 17℃, 18℃, 19℃, 20℃, 21℃, 22℃, 23℃, 24℃ or 25℃, and b is preferably recommended to be 16℃), it indicates that the ambient temperature has improved. At this time, combined with the obtained compressor frequency F1 of 2000, the mode of the heat exchanger can be further determined. If the compressor 2000 frequency F1 ≥ k*(Fmax+Fmin), where 1 / 3 ≤ k ≤ 5 / 8, for example, k can be 1 / 3, 3 / 8, 1 / 2, or 5 / 8, and preferably 1 / 2; Fmax is the maximum allowable operating frequency of the compressor 2000, and Fmin is the minimum allowable operating frequency of the compressor 2000, then it proves that the compressor 2000 frequency is relatively high, and the heat exchanger is still in a high-load mode. Therefore, the heat exchanger is determined to be in the first load mode. When the outdoor temperature T4 < b, the outdoor temperature has further improved. If the compressor 2000 frequency F1 ≥ m*(Fmax+Fmin), where 5 / 8 ≤ m ≤ 7 / 8, for example, m can be 5 / 8, 2 / 3, 3 / 4, or 7 / 8, and preferably 2 / 3, then it proves that the compressor 2000 frequency has further increased, thus proving that the load is too heavy. At this time, regardless of the outdoor temperature, the heat exchanger is in a high-load mode, and therefore, the heat exchanger is determined to be in the first load mode.

[0116] When the heat exchanger is used as a condenser and is in the first load mode, the heat exchanger enters the full flow path mode. In this way, the number of flow paths of the phase change working fluid is the sum of the first heat exchange tube group 300 and the second heat exchange tube group 400. The large number of heat exchange flow paths increases the heat exchange capacity under the larger load operation mode and achieves better heat exchange effect.

[0117] Meanwhile, when the heat exchanger is used in the outdoor unit of an air conditioner as a condenser, if the outdoor temperature is not too harsh and the compressor frequency (2000 rpm) is not too high, it indicates that the heat exchanger is operating under a low load. Specifically, when b ≤ T4 < a and F1 < k*(Fmax + Fmin), the outdoor temperature is not too high, indicating that the environment is not too harsh, and the compressor frequency (2000 rpm) is also low, thus it can be determined that the heat exchanger is in a low load mode, i.e., the second load mode mentioned above. When T4 < b and F1 < m*(Fmax + Fmin), the outdoor temperature is very low, providing a naturally favorable environment for the operation of the heat exchanger. At the same time, the compressor frequency (2000 rpm) is not too high, therefore, the load on the heat exchanger is not too large, and it can also be determined that the heat exchanger is in a low load mode.

[0118] When the heat exchanger is in the second load mode, the semi-flow path mode is selected. At this time, the number of flow paths is reduced by half compared to the first load mode, which can meet the requirement of increasing the heat transfer coefficient under a smaller load mode and achieve better heat exchange effect.

[0119] Please refer to Figure 5 and Figure 6 Understandably, when a heat exchanger is used in a refrigeration system and acts as an evaporator, the outdoor unit of the air conditioner also includes a compressor 2000, which is connected to the heat exchanger. At this time, the outdoor temperature is T4 and the compressor 2000 frequency is F2. When T4 < c; or when c ≤ T4 < d and F2 ≥ k*(Fmax + Fmin); or when T4 > d and F2 ≥ m*(Fmax + Fmin), the heat exchanger is determined to be in the first load mode.

[0120] When c≤T4<d and F2<k*(Fmax+Fmin); or when T4>d and F2<m*(Fmax+Fmin), the heat exchanger is determined to be in the second load mode.

[0121] Where 0≤c≤6℃, 6℃≤d≤20℃, 1 / 3≤k≤5 / 8, and 5 / 8≤m≤7 / 8.

[0122] In this invention, the heat exchanger is used, for example, in the outdoor unit of an air conditioner, and the heat exchanger acts as an evaporator while the air conditioner is in heating mode. The lower the ambient temperature, the harsher the environment, and thus the heat exchanger operates under a higher load. Alternatively, a higher compressor frequency (2000 rpm) indicates a greater load, and the heat exchanger operates under a higher load. Conversely, the heat exchanger operates under a lower load. In this invention, if the first load mode is greater than the second load mode, it indicates that the first load mode is a higher load mode and the second load mode is a lower load mode. This invention determines the heat exchanger mode by simultaneously acquiring the outdoor temperature T4 and the compressor frequency (2000 rpm) F, that is, by comprehensively considering both conditions, thereby making the determination of the heat exchanger mode more accurate.

[0123] Specifically, when the outdoor temperature T4 is less than c (where 0 ≤ c ≤ 6℃, and c can be 0, 1℃, 2℃, 3℃, 4℃, 5℃, or 6℃, and preferably 5℃), it indicates that the ambient temperature is very low. This means that when the air conditioner is in heating mode, regardless of the compressor 2000's operating frequency, the environmental conditions are very harsh. Therefore, the heat exchanger will inevitably be under heavy load, and it can be determined that the heat exchanger is in its first load mode. When the outdoor temperature c ≤ T4 < d (where 6℃ ≤ d ≤ 20℃, and d can be 6℃, 7℃, 8℃, 9℃, 10℃, 11℃, 12℃, 13℃, 14℃, 15℃, 16℃, 17℃, 18℃, 19℃, or 20℃, and preferably 16℃), it indicates that the ambient temperature has improved. In this case, combined with the compressor 2000's frequency F2, the heat exchanger's mode can be further determined. If the compressor 2000 frequency F2 ≥ k*(Fmax + Fmin), where 1 / 3 ≤ k ≤ 5 / 8 (e.g., k can be 1 / 3, 3 / 8, 1 / 2, 5 / 8, and preferably 1 / 2), and Fmax is the maximum allowable operating frequency of the compressor 2000, and Fmin is the minimum allowable operating frequency, then the compressor 2000 frequency is high, meaning the heat exchanger is still under heavy load. Therefore, the heat exchanger is determined to be in the first load mode. When the outdoor temperature T4 > d, the outdoor temperature improves further. If the compressor 2000 frequency F2 ≥ m*(Fmax + Fmin), where 5 / 8 ≤ m ≤ 7 / 8 (e.g., m can be 5 / 8, 2 / 3, 3 / 4, 7 / 8, and preferably 2 / 3), then the compressor 2000 frequency increases further, indicating an overload. At this point, regardless of the outdoor temperature, the heat exchanger is under heavy load, and therefore, the heat exchanger is determined to be in the first load mode. At this point, the heat exchanger is set to full flow path mode, thereby improving the heat exchange effect.

[0124] In this invention, when a heat exchanger is used, for example, in the outdoor unit of an air conditioner as an evaporator, if it can simultaneously ensure that the outdoor temperature is not too harsh and the compressor 2000 frequency is not too high, then the heat exchanger is in a low-load mode. Specifically, when c≤T4<d and F<k*(Fmax+Fmin), the outdoor temperature is not too low, indicating that the environment is not too harsh, and the compressor 2000 frequency is also low, thus it can be determined that the heat exchanger is in a low-load mode, i.e., the second load mode mentioned above. When T4>d and F<m*(Fmax+Fmin), the outdoor temperature is very high, providing a naturally excellent environment for the operation of the heat exchanger, and the compressor 2000 frequency is not too high. Therefore, the load on the heat exchanger during operation is not too large, and it can also be determined that the heat exchanger is in a low-load mode.

[0125] When the heat exchanger is in the second load mode, the heat exchanger is selected as a semi-flow path mode, which can meet the requirement of increasing the heat transfer coefficient under a smaller load mode and achieve better heat exchange effect.

[0126] Furthermore, it is understandable that the refrigerant flow direction within the heat exchanger differs depending on its operating mode. By obtaining the refrigerant flow direction, the mode of operation of the heat exchanger can be indirectly determined, thereby providing a signal for the opening or closing status of each control valve. This is simple, convenient, and effectively improves control efficiency. In this embodiment, when the refrigerant flow direction is from the liquid collection pipe 100 to the gas collection pipe 200, the heat exchanger is determined to be in evaporation mode. Based on controlling the fourth control valve 540 to open, the first and second control valves can be controlled to have the same opening and closing status, while the third control valve is controlled to have the opposite status to the first control valve. When the refrigerant flow direction is from the gas collection pipe 200 to the liquid collection pipe 100, the heat exchanger is determined to be in condenser operation mode. Based on controlling the fourth control valve 540 to close, the first and second control valves can be controlled to have the same opening and closing status, while the third control valve is controlled to have the opposite status to the first control valve.

[0127] In other embodiments, air conditioners that simultaneously provide cooling and heating typically include a four-way valve, which exhibits different states in cooling and heating modes. By monitoring the state of the four-way valve, it is possible to determine whether the air conditioner is in cooling or heating mode, and subsequently send a signal to the heat exchanger to cause it to operate in the appropriate mode, i.e., to switch to evaporation or condensation mode.

[0128] Optionally, when the fourth control valve 540 is an electronic expansion valve, the flow path control method for the heat exchanger further includes:

[0129] Step S6: Obtain the target operating frequency Fr of the refrigeration system;

[0130] Step S7: Determine the magnitude of the target operating frequency Fr and the third preset value c;

[0131] Step S8: If Fr≤c, then set the initial opening of the electronic expansion valve to the first opening A and maintain it for t1; if Fr>c, then set the initial opening of the electronic expansion valve to the second opening B and maintain it for t2.

[0132] Where c = l * (Fmax + Fmin), l ranges from 0.45 to 0.75, A is less than B, Fmax is the maximum operating frequency of compressor 2000, and Fmin is the minimum operating frequency of compressor 2000;

[0133] Step S9: After initialization, the coil temperature T3 of the condenser and the suction temperature Tx of the compressor 2000 are detected every first preset time interval;

[0134] Step S10: Determine the difference between the coil temperature T3 and the suction temperature Tx of the heat exchanger, and adjust the opening adjustment value of the electronic expansion valve according to the magnitude of the difference.

[0135] In this embodiment, when the fourth control valve 540 is an electronic expansion valve, in order to enhance the heating effect, the electronic expansion valve is opened when the heat exchanger is in evaporation mode. The initial opening degree and holding time of the electronic expansion valve are set according to the target operating frequency of the refrigeration system, thereby effectively saving energy and improving the efficiency of gas-liquid separation.

[0136] Specifically, the target operating frequency is compared with a third preset value c. Here, the third preset value is the ratio of the sum of the maximum and minimum operating frequencies of the compressor 2000. The ratio coefficient l ranges from 0.45 to 0.75, for example, 0.5, 0.6, or 0.7. In a preferred embodiment, the ratio coefficient is selected as 0.5, so that the target operating frequency is compared with half of the sum of Fmax and Fmin, which can best reflect the load mode of the refrigeration system. This allows for more accurate initial control of the opening and holding time of the electronic expansion valve, thereby improving heat exchange efficiency.

[0137] Specifically, the heat exchanger is in heating mode. Combined with the obtained frequency Fr of compressor 2000, the operating mode of the heat exchanger is further determined. If the target operating frequency Fr of compressor 2000 is ≤ c, it indicates that the target operating frequency of compressor 2000 is low, meaning the heat exchanger may be operating under low load. Therefore, the opening degree of the electronic expansion valve can be set to a relatively small first opening degree A. Here, A ranges from 20P to 100P, for example, 30P, 40P, 50P, 60P, 70P, 80P, 90P, etc., preferably 50P. The holding time is t1, ranging from 2min to 15min, for example, 3min, 4min, 5min, 6min, 8min, 10min, 12min, etc. In a preferred embodiment, t1 is set to 5min, thereby effectively saving energy and improving heat exchange efficiency while meeting low load requirements. If Fr > c, it indicates that the compressor 2000 target operating frequency is high, and the heat exchanger may be operating under high load. Therefore, the initial opening degree of the electronic expansion valve is set to the second opening degree B, and the range of B is 50P~150P, such as 50P, 60P, 70P, 80P, 90P, 100P, 120P, 140P, etc. In a preferred embodiment, the second opening degree B is selected as 80P, and the holding time is t2, and the range of t2 is 1min~15min, such as 2min, 3min, 4min, 5min, 6min, 8min, 10min, 12min, etc. Preferably, t2 is selected as 2min, so as to ensure the heat exchange effect while meeting the high load requirements.

[0138] After initial setup, to further improve heat exchange efficiency and energy saving during subsequent operation of the heat exchanger, the opening of the fourth control valve 540 can be adjusted periodically based on the difference between the temperature T3 at the center of the heat exchanger coil and the suction temperature Tx of the compressor 2000. It is understood that the temperature T3 at the center of the outdoor unit's coil represents the pressure value during heat exchange. When the air conditioner is in heating mode, the heat exchanger is in evaporation mode. To effectively protect the compressor 2000, the suction superheat of the compressor 2000 should not be too low, nor too high, otherwise it will affect the operating conditions. Therefore, the difference between the temperature at the center of the heat exchanger coil and the suction temperature of the compressor 2000 needs to be maintained within a dynamic equilibrium range to improve the heat exchanger's performance.

[0139] Optionally, the step of determining the difference between the coil temperature T3 of the heat exchanger and the suction temperature Tx of the compressor 2000, and adjusting the opening adjustment value of the electronic expansion valve according to the magnitude of the difference, specifically includes:

[0140] Step S101: Let the difference be ∆T. If ∆T < -1.5, then increase the opening of the electronic expansion valve by a first opening value E; if -1.5 < ∆T ≤ -0.5, then increase the opening of the electronic expansion valve by a second opening value F.

[0141] Step S102: If -0.5 < ∆T ≤ 0.5, then control the opening degree of the electronic expansion valve to remain unchanged;

[0142] Step S103: If 0.5 < ∆T ≤ 1.5, then control the opening of the electronic expansion valve to decrease by the third opening value - (F+1).

[0143] Step S104: If ∆T > 1.5, then control the opening of the electronic expansion valve to decrease by the fourth opening value - (E+1).

[0144] Where E > F, optionally, the first preset time ranges from 30s to 300s, F ranges from 2P to 15P, and E ranges from 4P to 30P.

[0145] In this embodiment, the difference between the two is set to ∆T. If ∆T < -1.5, it means that the coil temperature of the heat exchanger is lower than the suction temperature and the difference between the two is large. At this time, the suction superheat is large. Therefore, it is necessary to increase the opening of the electronic expansion valve. The corresponding first opening value is E (E can be selected from 4P to 30P, for example, 5P, 6P, 7P, 8P, 10P, 15P, 20P, 25P, 30P, etc., preferably 8P). This will saturate the refrigerant at the evaporator outlet, increase the evaporation temperature, decrease the suction temperature, and reduce the effective suction superheat, thereby improving the heat exchange effect. Of course, if -1.5 < ∆T ≤ -0.5, then the corresponding intake superheat is not very large. The opening of the electronic expansion valve can be increased by a second opening value F. Here, the value of F is less than E, and its range can be 2P~15P, for example, 4P, 5P, 7P, 8P, 10P, 15P, etc., preferably 4P, so as to ensure an effective and appropriate intake superheat and improve the heat exchange effect.

[0146] Understandably, when the difference between the two is equal, i.e. -0.5 < ∆T ≤ 0.5, the opening of the electronic expansion valve can be kept constant.

[0147] Of course, when 0.5 < ∆T ≤ 1.5, or ∆T > 1.5, it means that the coil temperature of the heat exchanger is greater than the suction temperature, and the difference between the two is large. In this case, it is necessary to reduce the opening of the electronic expansion valve. In the former case, the reduction value is smaller than that in the latter case. That is, when 0.5 < ∆T ≤ 1.5, the opening of the electronic expansion valve is reduced by the third opening value (F+1), preferably 5P. When ∆T > 1.5, the opening of the electronic expansion valve is reduced by the fourth opening value (E+1), preferably 9P, so as to ensure an effective and appropriate suction superheat and improve the heat exchange effect.

[0148] The present invention also provides a readable storage medium storing a flow path control program for a heat exchanger, wherein when the flow path control program for the heat exchanger is executed by a processor, the flow path control program for the heat exchanger implements the steps of the above-described flow path control method for the heat exchanger.

[0149] Specific embodiments of the readable storage medium of the present invention can be found in the various embodiments of the flow path control method for the heat exchanger described above, and will not be repeated here.

[0150] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A flow path control method for a heat exchanger, wherein the heat exchanger is used in a refrigeration system, characterized in that, The heat exchanger includes: Collection tube; Gas collection tube; A gas-liquid separator, comprising two liquid ends and one gas end, wherein the gas end is connected to the gas collecting pipe via a first pipeline; A separable module, one end of which is connected to the liquid end of the gas-liquid separator via a second pipeline, and the other end of which is connected to the liquid collection pipe via a third pipeline; A variable flow path module, comprising: a plurality of parallel first heat exchange tube groups, a plurality of parallel second heat exchange tube groups, a first solenoid valve, a second solenoid valve, and a third solenoid valve; One end of the first heat exchange tube assembly is connected to the gas collecting pipe through the fourth pipe, and the other end is connected to the other liquid end through the fifth pipe; one end of the second heat exchange tube assembly is connected to the gas collecting pipe through the sixth pipe, and the other end is connected to the other liquid end through the seventh pipe. The first solenoid valve is located in the fifth pipeline, and the second solenoid valve is located in the sixth pipeline; one end of the third solenoid valve is connected to the end of the first solenoid valve away from the gas collecting pipe, and the other end is connected to the end of the second solenoid valve away from the other liquid end; and The fourth control valve is located on the first pipeline; The flow path control method includes: Obtain the operating mode of the heat exchanger and the load mode of the refrigeration system; When the operating mode is evaporation mode, the fourth control valve is opened. When the operating mode is condensation mode, the fourth control valve is closed. When the load mode is the first load mode, the variable flow path module adopts the full flow path mode, that is, it controls the first solenoid valve and the second solenoid valve to be turned on, and controls the third solenoid valve to be turned off; When the load mode is the second load mode, the variable flow path module adopts a half flow path mode, that is, it controls the first solenoid valve and the second solenoid valve to close and controls the third solenoid valve to open, wherein the first load is greater than the second load; When the fourth control valve is an electronic expansion valve, the flow path control method for the heat exchanger further includes: Obtain the target operating frequency Fr of the refrigeration system; Determine the magnitude of the target operating frequency Fr and the third preset value c; If Fr≤c, the initial opening of the electronic expansion valve is set to the first opening A, and the holding time is t1; if Fr>c, the initial opening of the electronic expansion valve is set to the second opening B, and the holding time is t2. Where c = l * (Fmax + Fmin), l ranges from 0.45 to 0.75, A is less than B, Fmax is the maximum operating frequency of the compressor, and Fmin is the minimum operating frequency of the compressor; After initialization, the coil temperature and suction temperature of the heat exchanger are detected every first preset time interval; Determine the difference between the coil temperature and the suction temperature of the heat exchanger, and adjust the opening value of the electronic expansion valve according to the magnitude of the difference.

2. The flow path control method for a heat exchanger as described in claim 1, characterized in that, The separable module includes multiple first separation flow paths, which are connected in parallel.

3. The flow path control method for a heat exchanger as described in claim 2, characterized in that, The number of flow paths in the separable module is less than the maximum number of flow paths in the variable flow path module.

4. The flow path control method for a heat exchanger as described in any one of claims 1 to 3, characterized in that, The number of the first heat exchange tube group and the second heat exchange tube group are equal. A third solenoid valve is provided. The end of each first heat exchange tube group near the liquid collecting pipe is connected to one end of the third solenoid valve. The end of each second heat exchange tube group near the gas collecting pipe is connected to the other end of the third solenoid valve.

5. The flow path control method for a heat exchanger as described in any one of claims 1 to 3, characterized in that, The fourth control valve is a one-way valve, and the one-way valve is open from the gas end to the gas collecting pipe. Alternatively, the fourth control valve may be an electronic expansion valve.

6. The flow path control method for a heat exchanger as described in any one of claims 1 to 3, characterized in that, The heat exchanger also includes a common heat exchange tube assembly, one end of which is connected to the fourth pipeline and the other end of which is connected to the seventh pipeline.

7. The flow path control method for a heat exchanger as described in any one of claims 1 to 3, characterized in that, The refrigeration system also includes a compressor, and the specific steps for obtaining the operating mode of the heat exchanger and the load mode of the refrigeration system include: When the heat exchanger is in condensing mode, obtain the outdoor temperature T4 and the compressor operating frequency F1; When the outdoor temperature T4 is greater than or equal to the first preset value a; or when the outdoor temperature is less than the first preset value a but greater than the second preset value b, and the compressor frequency F1 ≥ k*(Fmax+Fmin); or when the outdoor temperature is less than the second preset value b, and the compressor frequency F1 ≥ m*(Fmax+Fmin), the refrigeration system is set to the first load mode. When the outdoor temperature T4 is less than the first preset value a and greater than or equal to the second preset value b, and the compressor frequency F1 < k*(Fmax+Fmin); or, when the outdoor temperature is less than the second preset value b, and the compressor frequency F1 < m*(Fmax+Fmin), the refrigeration system is set to the second load mode. Where a is greater than b, k ranges from 1 / 3 to 5 / 8, m ranges from 5 / 8 to 7 / 8, Fmax is the maximum operating frequency of the compressor, and Fmin is the minimum operating frequency of the compressor.

8. The flow path control method for a heat exchanger as described in claim 7, characterized in that, The first preset value a ranges from 26℃ to 35℃, and the second preset value b ranges from 10℃ to 25℃.

9. The flow path control method for a heat exchanger as described in any one of claims 1 to 3, characterized in that, The step of determining the difference between the coil temperature and the suction temperature of the heat exchanger, and adjusting the opening value of the electronic expansion valve according to the magnitude of the difference, specifically includes: Let the difference be ∆T. If ∆T < -1.5, then the opening degree of the electronic expansion valve is increased by a first opening degree value E; if -1.5 < ∆T ≤ -0.5, then the opening degree of the electronic expansion valve is increased by a second opening degree value F. If -0.5 < ∆T ≤ 0.5, then the opening degree of the electronic expansion valve remains unchanged; If 0.5 < ∆T ≤ 1.5, then the opening degree of the electronic expansion valve is reduced by the third opening value - (F+1). If ∆T>1.5, then the opening degree of the electronic expansion valve is reduced by the fourth opening degree value - (E+1). Where E > F.

10. The flow path control method for a heat exchanger as described in claim 9, characterized in that, The first preset time ranges from 30s to 300s, F ranges from 2P to 15P, and E ranges from 4P to 30P.

11. A readable storage medium, characterized in that, The readable storage medium stores a flow path control program for a heat exchanger, which, when executed by a processor, implements the steps of the flow path control method for a heat exchanger as described in any one of claims 1 to 10.

12. An air conditioner, characterized in that, The heat exchanger includes one capable of performing the flow path control method for the heat exchanger as described in any one of claims 1 to 10.

13. The air conditioner as described in claim 12, characterized in that, The air conditioner includes an outdoor unit, and the heat exchanger is located inside the outdoor unit.

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