A heat pump unit with a new type of V-shaped fin

Abstract

The application provides a heat pump unit with V-shaped fins, comprising a V-shaped fin, a four-way valve, a compressor, a double-pipe heat exchanger, a central electronic expansion valve, a plurality of electronic valves and a controller connected in sequence through refrigerant circulation pipelines; the V-shaped fin comprises three sub-fins, each sub-fin is connected with the four-way valve through an electronic valve, and three electronic valves share a pipeline with one end of the four-way valve; four valves of the four-way valve are connected with the V-shaped fin, an exhaust pipe of the compressor, an air suction pipe of the compressor and the double-pipe heat exchanger respectively; one end of the central electronic expansion valve is connected with the double-pipe heat exchanger, and the other end is connected with three sub-fins of the V-shaped fin respectively; the controller is used for obtaining the operating condition of the unit and regulating and controlling the operation of the unit. The heat pump unit can relieve the icing phenomenon at the bottom of the traditional V-shaped fin in the defrosting mode, and optimize the energy utilization efficiency of the unit under partial load.

Description

Technical Field

[0001] This invention relates to the field of air conditioning heat pump systems, and in particular to a heat pump unit employing a novel V-shaped fin. Background Technology

[0002] Existing traditional heat pump air conditioners using V-shaped fins have structural limitations. In heating mode, the utilization rate of the bottom of the V-shaped fins is low. When the finned heat exchanger is under partial load, that is, when the output power of the finned heat exchanger is less than the rated power, the high-temperature gas generated at this time expands due to the high temperature. Therefore, most of the high-temperature gas is concentrated in the upper and middle fins, resulting in low utilization of the bottom fins. If the amount of low-temperature refrigerant flowing through all parts of the V-shaped fins is made uniform, some low-temperature refrigerant will be wasted in the bottom fins. In defrosting mode, less high-temperature refrigerant passes through the bottom of the fins, and water flows to the bottom of the fins. In ultra-low temperature environments, water may freeze at the bottom of the fins before it flows out. This freezing is extremely difficult to remove and will affect the overall lifespan of the unit. Summary of the Invention

[0003] To address the aforementioned issues, this invention provides a heat pump unit employing a novel V-shaped fin design. Simultaneously, it improves the structure and logic control of existing heat pump units, enabling them to solve the bottom icing problem during the defrosting process of low-temperature heat pump air conditioners and optimize the unit's energy utilization efficiency under partial load.

[0004] This invention is achieved through the following technical solution:

[0005] On one hand, this invention provides a heat pump unit employing a novel V-shaped fin, comprising, in sequence via refrigerant circulation piping, V-shaped fins, a four-way valve, a compressor, a shell-and-tube heat exchanger, a central electronic expansion valve, multiple electronic valves, and a controller.

[0006] The V-shaped fin includes three sub-fins, each sub-fin is connected to the four-way valve through an electronic valve, and the three electronic valves share a common pipe at the end connected to the four-way valve.

[0007] The four valves of the four-way valve are respectively connected to the V-shaped fins, the compressor exhaust pipe, the compressor gas collecting pipe and the shell-and-tube heat exchanger.

[0008] One end of the central electronic expansion valve is connected to the shell-and-tube heat exchanger, and the other end is connected to the three sub-fins of the V-shaped fins.

[0009] The controller is used to acquire the unit's operating status and regulate the unit's operation.

[0010] Furthermore, the three fins are divided into a first fin, a second fin, and a third fin;

[0011] The central electronic expansion valve is further connected to the first fin by an electronic valve 4, and to the second fin by an electronic valve 5. The central electronic expansion valve is further connected to the third fin by an electronic valve 6.

[0012] Furthermore, a liquid separator is provided between the first fin and the electronic valve 4, between the second fin and the electronic valve 5, and between the third fin and the electronic valve 6. The liquid separator is used to separate multiple capillaries, which are evenly distributed in different parts of the corresponding fins.

[0013] Furthermore, each of the aforementioned fins is also provided with an air collecting pipe.

[0014] The gas collecting pipe can guide the flow of refrigerant, optimize the flow path structure, improve the efficiency of refrigerant flow, and accelerate refrigerant circulation.

[0015] Furthermore, each of the sub-fins is provided with a coil temperature head, which is connected to the controller and is used to detect the coil temperature of the corresponding sub-fin.

[0016] Furthermore, the controller adjusts the opening degree of the electronic valve through the following steps:

[0017] Obtain the current operating mode of the heat pump unit;

[0018] If the heat pump unit is in defrost mode, adjust the opening of electronic valve 1, electronic valve 2, and electronic valve 3 so that the opening of electronic valve 1, electronic valve 2, and electronic valve 3 is arranged from small to large.

[0019] If the heat pump unit is in heating mode, the current operating frequency H and cumulative operating time t of the compressor are obtained, and the current operating frequency H and cumulative operating time t of the compressor are compared with preset conditions. Based on the comparison results, the opening degree of electronic valve 4, electronic valve 5 and electronic valve 6 are adjusted.

[0020] Furthermore, when the heat pump unit is in heating mode, its electronic valve adjustment method specifically includes:

[0021] Obtain the compressor's current operating frequency H and cumulative operating time t, and compare the compressor's current operating frequency H with a preset frequency threshold H1, and compare the compressor's cumulative operating time t with a first preset operating time t1;

[0022] If the compressor's cumulative running time t is greater than the first preset running time, the compressor's current frequency H is less than the preset frequency threshold H1, and the compressor's cumulative running time t is less than the second preset running time t2, the unit enters a partially compliant state control logic.

[0023] Obtain the coil temperature T1, T2, and T3 of the first fin.

[0024] When T1 is satisfied simultaneously<T3,T3> When T2 and T3-T1 < 1, adjust the opening of electronic valves 4, 5, and 6 according to the actual load demand.

[0025] Furthermore, before comparing the compressor's cumulative running time t with the first preset running time t1, the following must also be satisfied:

[0026] During the cumulative running time t of the compressor, the current operating frequency H of the compressor is always greater than the preset frequency threshold H1.

[0027] Furthermore, the actual load requirement in the control method is determined by a preset temperature.

[0028] In summary, this invention improves the structure and logic control of existing heat pump units by dividing the V-shaped fins into three sub-fins. Each sub-fin is connected to the four-way valve via an electronic valve, and the three electronic valves share a common pipe at the end connected to the four-way valve. When the operating state of the heat pump unit meets preset conditions, the opening degree of the corresponding electronic valve is adjusted in a gradient manner. This solves the problem of bottom icing during defrosting in traditional V-shaped fin low-temperature heat pump air conditioners and optimizes the energy utilization efficiency of the unit under partial load.

[0029] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description

[0030] Figure 1 A structural block diagram of a heat pump unit using a novel V-shaped fin is provided for this invention;

[0031] Figure 2 The present invention provides a flowchart of a controller for adjusting the opening of an electronic valve in a heat pump unit employing a novel V-shaped fin.

[0032] Reference numerals: 10: First fin; 11: Second fin; 12: Third fin. Detailed Implementation

[0033] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of this invention. The singular forms “a,” “the,” and “the” used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that, unless otherwise stated, “a plurality” means two or more; and the term “and / or” as used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0034] In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. In the description of the present invention, it should be understood that the terms "first," "second," "third," etc., are used only for distinction and not to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0035] In air conditioning heat pump systems, finned heat exchangers are commonly used. Fins are metal sheets with high thermal conductivity added to the surface of the heat exchange device to increase the heat exchange surface area. Traditional fin types are divided into V-shaped fins and W-shaped fins, etc. V-shaped fins have a larger heat dissipation area and space and dissipate heat faster. However, they have energy consumption problems and are prone to ice formation at the bottom of the fins during defrosting, which affect the performance of air conditioning heat pump systems. To solve this problem, the inventor has proposed the following solution to address the above issues.

[0036] Please refer to Figure 1 , Figure 2 , Figure 1 A structural block diagram of a heat pump unit using a novel V-shaped fin is provided for this invention; Figure 2 The present invention provides a flowchart of a controller adjusting the opening of an electronic valve in a heat pump unit employing a novel V-shaped fin, wherein the heat pump unit employing the novel V-shaped fin includes:

[0037] The following components are connected sequentially via refrigerant circulation piping: V-fins, four-way valve, compressor, shell-and-tube heat exchanger, central electronic expansion valve, multiple electronic valves and controllers (not shown in the figure);

[0038] The V-shaped fin includes three sub-fins, each sub-fin is connected to the four-way valve through an electronic valve, and the three electronic valves share a common pipe at the end connected to the four-way valve.

[0039] The four valves of the four-way valve are respectively connected to the V-shaped fins, the compressor exhaust pipe, the compressor gas collecting pipe and the shell-and-tube heat exchanger.

[0040] One end of the central electronic expansion valve is connected to the shell-and-tube heat exchanger, and the other end is connected to the three sub-fins of the V-shaped fins.

[0041] The controller is used to acquire the unit's operating status and regulate the unit's operation.

[0042] The inventors first improved the V-shaped fin structure of the heat pump system by splitting a single V-shaped fin into three sub-fin parts. Each sub-fin is equipped with a gas collecting pipe and a liquid distributing pipe, and an electronic valve is installed in front of the liquid distributing head. The three sub-fins are fixed by a fixing device. Then, the first sub-fin 10 is connected to the electronic valve 1, the second sub-fin 11 is connected to the electronic valve 2, and the third sub-fin 12 is connected to the electronic valve 3. The other ends of the electronic valves 1, 2, and 3 share a common pipe and are connected to the four-way valve.

[0043] At this point, the unit can obtain the unit's operating mode through the controller. After detecting the unit's operating status, it is determined whether the unit's operating status meets the preset conditions. If it does, electronic valves 1, 2, and 3 open. In defrost mode, electronic valves 1, 2, and 3 obtain high-temperature refrigerant from the compressor through the four-way valve. The high-temperature refrigerant flows into the corresponding fins through electronic valves 1, 2, and 3 respectively, avoiding the problem of water freezing at the bottom of the fins in ultra-low temperature environments due to water flowing to the bottom of the fins.

[0044] In another embodiment, the inventors further improved the heat pump system by adding an electronic valve 4 between the central electronic expansion valve and the first sub-fin 10, an electronic valve 5 between the central electronic expansion valve and the second sub-fin 11, and an electronic valve 6 between the central electronic expansion valve and the third sub-fin 12.

[0045] The unit's operating mode is obtained through the controller, and the opening of the fourth, fifth, and electronic valves 6 is adjusted according to the operating mode. In the traditional V-shaped fin structure, in the heating mode, the high-temperature gas generated expands due to its high temperature, so most of the high-temperature gas is concentrated in the upper and middle fins. Therefore, the utilization rate of the bottom fins is not high, but the lower fins cannot be removed. When the heat exchange of the upper and middle fins is insufficient, the lower fins need to supplement it. In this invention, the original V-shaped fin structure is divided into three smaller sub-fins, each connected to one of three electronic valves. In heating mode, the controller controls the opening of these three electronic valves, ensuring that the opening of electronic valve 5 (connected to the second sub-fin 11) and electronic valve 6 (connected to the third sub-fin 12) is greater than the opening of electronic valve 4 (connected to the first sub-fin 10). This controls the flow of low-temperature refrigerant to the second and third sub-fins 11 and 12, allowing for sufficient evaporation and improving the evaporation efficiency of the finned heat exchanger under partial load. Without this control, the refrigerant flows to the first sub-fin 10, resulting in lower evaporation efficiency due to reduced airflow at the bottom, thus lowering the unit's energy efficiency. Therefore, this structure alleviates the energy consumption problem of traditional V-shaped fins in heating mode.

[0046] In another embodiment, a distributor is provided between the first fin 11 and the electronic valve 4, between the second fin 11 and the electronic valve 5, and between the third fin 12 and the electronic valve 6. The distributor is used to separate multiple capillaries, which are evenly distributed at different locations on the corresponding fins. This ensures that when the electronic valves 4, 5, and 6 are opened, the refrigerant can reach all parts of the fins evenly, improving cooling efficiency.

[0047] However, the above structural improvements can only provide coarse adjustments to the operating status of the heat pump system. For air conditioning units with higher precision requirements, the effect is not significant. Therefore, based on the improved heat pump unit, the inventors have also proposed a method for adjusting the opening of the electronic valve in a heat pump unit using a novel V-shaped fin. This method accurately adjusts the opening based on the unit's operating status rather than its operating mode. Specifically, the method includes:

[0048] S10: Obtain the current operating mode of the heat pump unit.

[0049] S20: If the heat pump unit is in defrost mode, adjust the opening of electronic valve 1, electronic valve 2, and electronic valve 3 so that the opening of electronic valve 1, electronic valve 2, and electronic valve 3 is arranged from large to small.

[0050] This allows the high-temperature refrigerant to pass through the four-way valve and enter the first fin in large quantities via electronic valve 1 in defrost mode, thus solving the problem of ice formation at the bottom of the fins.

[0051] S22: If the heat pump unit is in heating mode, obtain the current operating frequency H and cumulative operating time t of the compressor of the unit, and compare the current operating frequency H and cumulative operating time t of the compressor of the unit with preset conditions. Based on the comparison results, adjust the opening degree of electronic valve 4, electronic valve 5 and electronic valve 6.

[0052] In another preferred embodiment, when the heat pump unit is in heating mode, the method for adjusting its expansion valve specifically includes:

[0053] S22A: Obtain the current operating frequency H and the cumulative operating time t of the compressor, and compare the current operating frequency H of the compressor with the preset frequency threshold H1, and compare the cumulative operating time t of the compressor with the first preset operating time t1.

[0054] In the heat pump unit used in this invention, the preset threshold frequency of the unit is 60 Hz, and the first preset running time t1 is 5 minutes. The preset threshold frequency and the first preset running time are the comprehensive performance coefficient of the test model and the threshold of the compression frequency under partial load. Taking into account the operating status of the unit, it is determined whether it is necessary to separately control the opening degree of electronic valves 4, 5, and 6.

[0055] S22B: If the compressor's cumulative running time t is greater than the first preset running time, the compressor's current frequency H is less than the preset frequency threshold H1, and the compressor's cumulative running time t is less than the second preset running time t2, the unit enters a state control logic that meets certain conditions.

[0056] S22C: Obtain the coil temperature T1, T2, and T3 of the first fin 1011; when T1 is satisfied simultaneously...<T3,T3> When T2 and T3-T1 < 1, adjust the opening of electronic valves 4, 5, and 6 according to the actual load demand.

[0057] The actual load demand is determined directly by the temperature set by the user, and the unit operates according to the set temperature after the user sets the temperature.

[0058] In another embodiment, the compressor's cumulative running time t must also satisfy the following condition before being compared with the first preset running time t1:

[0059] During the cumulative running time t of the compressor, the current operating frequency H of the compressor is always greater than the preset frequency threshold H1.

[0060] Frequency directly reflects the operating status of the unit. After the unit is running stably, it will adjust the frequency according to different load demands to achieve energy saving. Combined with the running time, the variable frequency unit needs a frequency ramp-up process from startup to stable operation. The unit is unstable during the frequency ramp-up process, so it is necessary to coordinate with the running time to prevent the unit from entering partial load logic control during the frequency ramp-up phase. The setting value of t' (the minimum cumulative stable running time of the unit) varies from manufacturer to manufacturer and is not fixed.

[0061] In summary, this invention improves the structure and logic control of existing heat pump units by dividing the V-shaped fins into three sub-fins. Each sub-fin is connected to the four-way valve via an electronic valve, and the three electronic valves share a common pipe at the end connected to the four-way valve. When the operating state of the heat pump unit meets preset conditions, the opening degree of the corresponding electronic valve is adjusted in a gradient manner. This solves the problem of bottom icing during defrosting in traditional V-shaped fin low-temperature heat pump air conditioners and optimizes the energy utilization efficiency of the unit under partial load.

[0062] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and the present invention also intends to include these modifications and variations.

Claims

1. A heat pump unit employing V-shaped fins, comprising, in sequence via refrigerant circulation piping, V-shaped fins, a four-way valve, a compressor, a shell-and-tube heat exchanger, a central electronic expansion valve, multiple electronic valves, and a controller, characterized in that: The V-shaped fin includes three sub-fins, namely a first sub-fin, a second sub-fin, and a third sub-fin; the first sub-fin is connected to electronic valve 1, the second sub-fin is connected to electronic valve 2, and the third sub-fin is connected to electronic valve 3; the other ends of electronic valves 1, 2, and 3 share a common pipe connected to the four-way valve; each sub-fin is equipped with a coil temperature sensor, which is connected to the controller and is used to detect the coil temperature of the corresponding sub-fin; The four valves of the four-way valve are respectively connected to the V-shaped fins, the compressor's exhaust pipe, the compressor's suction pipe, and the shell-and-tube heat exchanger. One end of the central electronic expansion valve is connected to the shell-and-tube heat exchanger, and the other end is connected to the three sub-fins of the V-shaped fins respectively; the central electronic expansion valve also includes an electronic valve 4 between the central electronic expansion valve and the first fin, an electronic valve 5 between the central electronic expansion valve and the second fin, and an electronic valve 6 between the central electronic expansion valve and the third fin. The controller is used to acquire the unit's operating status and to control the opening degree of the electronic valve through an adjustment method, specifically through the following steps: Obtain the current operating mode of the heat pump unit; If the heat pump unit is in defrost mode, adjust the opening of electronic valve 1, electronic valve 2, and electronic valve 3 so that the opening of electronic valve 1, electronic valve 2, and electronic valve 3 is arranged from small to large. If the heat pump unit is in heating mode, obtain the current operating frequency H and the cumulative operating time t of the compressor, compare the current operating frequency H of the compressor with the preset frequency threshold H1, and compare the cumulative operating time t of the compressor with the first preset operating time t1. If the compressor's cumulative running time t is greater than the first preset running time, the compressor's current frequency H is less than the preset frequency threshold H1, and the compressor's cumulative running time t is less than the second preset running time t2, the unit enters the partial load state control logic. Obtain the coil temperature T1 of the first fin, the coil temperature T2 of the second fin, and the coil temperature T3 of the third fin. When T1 is satisfied simultaneously<T3,T3> When T2 and T3-T1 < 1, adjust the opening of electronic valves 4, 5, and 6 according to the actual load demand.

2. A heat pump unit employing V-shaped fins according to claim 1, characterized in that: A liquid separator is provided between the first fin and the electronic valve 4, between the second fin and the electronic valve 5, and between the third fin and the electronic valve 6. The liquid separator is used to separate multiple capillaries, which are evenly distributed in different parts of the corresponding fin.

3. A heat pump unit employing V-shaped fins according to claim 2, characterized in that: Each of the aforementioned fins is also provided with an air collecting pipe.

4. A heat pump unit employing V-shaped fins according to claim 3, characterized in that, Before the controller compares the compressor's cumulative running time t with the first preset running time t1, it must also satisfy the following: During the cumulative running time t of the compressor, the current operating frequency H of the compressor is always greater than the preset frequency threshold H1.

5. A heat pump unit employing V-shaped fins according to claim 4, characterized in that: The actual load requirement in the adjustment method is determined by a preset temperature.

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