A precise control method for outdoor fans of multi-split air conditioners

Abstract

The invention discloses a method for accurately controlling an outdoor fan of a multi-split air conditioner, comprising the following steps: step 1) determining the initial gear of the outdoor fan; step 2) the outdoor fan selects a control scheme according to the ambient temperature; step 3) when the ambient temperature T4>A, the fan selection scheme 1 controls the gear of the fan by the condensation temperature and the condensation pressure; when the ambient temperature T4<B, the fan selection scheme 2 controls the gear of the fan by the temperature difference between the ambient temperature T4 and the condenser temperature T3; when the ambient temperature T4 is between A and B, the outdoor fan maintains the initial gear operation. In this way, the air conditioner can more accurately control the fan speed in the heating mode, avoid rapid frosting caused by excessive fan speed, and improve the heating comfort and energy saving and consumption reduction.

Description

Technical Field

[0001] The invention relates to the field of multi-split air conditioners, and in particular to a precise control method for an outdoor fan of a multi-split air conditioner. Background Art

[0002] At present, there are two main methods for controlling outdoor fans of multi-split air conditioners on the market: one is outdoor environment control; the other is target high voltage control.

[0003] The patent document with publication number CN109210673B discloses a control method, device and air-conditioning system for an outdoor fan, which obtains industrial control parameter information; determines a target high pressure value according to the industrial control parameter information; determines a target saturation temperature value according to the target high pressure value; and controls the operating parameters of the outdoor fan according to the target saturation temperature value, so that the difference between the high pressure saturation temperature value of the system to which the outdoor fan belongs and the target saturation temperature value is within a preset accuracy range, thereby achieving precise control of the high pressure.

[0004] In the prior art, when the air conditioner is in cooling mode, the control method of the outdoor fan in the prior art can be used for control. However, when the air conditioner is in heating mode, especially in low-temperature heating mode, when the exhaust superheat of the compressor fluctuates, the high-pressure saturation temperature value of the system is prone to fluctuate, thereby affecting the control effect of the fan; simple high-pressure control may cause the air conditioner to frost faster, and frosting will also affect the high-pressure saturation temperature value of the system, thereby affecting the control effect of the fan, and failing to achieve the purpose of precise control. Summary of the invention

[0005] In order to solve the problem of low fan control accuracy in the heating mode of the air conditioner in the prior art, the purpose of the present invention is to provide a method for accurately controlling the outdoor fan of a multi-split air conditioner. The initial wind speed is determined by the ambient temperature, and the control scheme of the subsequent wind speed is selected. The fan speed of the multi-split air conditioner can be controlled more accurately in the heating mode, avoiding rapid frosting caused by excessive fan speed, while improving the heating comfort and energy saving.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solution: The specific control of the fan is as follows:

[0007] Step 1) determining the initial gear position of the outdoor fan;

[0008] Step 2) The outdoor fan selects a control scheme according to the ambient temperature;

[0009] Step 3) When the ambient temperature T4>A, fan selection scheme 1 controls the fan gear by the condenser temperature T3 and the condensing pressure; when the ambient temperature T4<B, fan selection scheme 2 controls the fan gear by the temperature difference between the ambient temperature T4 and the condenser temperature T3; when the ambient temperature T4 is between A and B, the outdoor fan maintains the initial gear operation.

[0010] Preferably, in step 1), the initial wind speed of the fan is determined by the ambient temperature T4 and the operating capacity of the outdoor unit.

[0011] As a preference, a specific manner of determining the initial wind speed is as follows: the lower the ambient temperature T4, the larger the initial wind speed; and the greater the operating capacity of the outdoor unit, the larger the initial wind speed.

[0012] Preferably, the specific control scheme of scheme one in step 3) is: after the fan runs at the initial wind speed for M minutes, when the condenser temperature T3≥C and the condensing pressure≤D, the wind speed of the fan is increased by one level; when the condenser temperature T3≥E and the condensing pressure≥F, the wind speed of the fan is decreased by one level; when the condenser temperature T3<G and the condensing pressure<F, the wind speed of the fan is increased by one level; under other conditions, the wind speed of the fan remains unchanged.

[0013] Preferably, the specific control scheme of scheme 2 described in step 3) is: after the fan runs at the initial wind speed for M minutes, if the temperature value of the ambient temperature T4 is always greater than H within M minutes when the fan runs at the initial wind speed, the gear of the fan is controlled by the temperature difference between the ambient temperature T4 and the condenser temperature T3; otherwise, the fan continues to run at the initial gear.

[0014] Preferably, the specific process of controlling the gear of the fan by the temperature difference between the ambient temperature T4 and the condenser temperature T3 is: when the ambient temperature T4-condenser temperature T3<I, the wind speed of the fan is reduced by one level; when I≤ambient temperature T4-condenser temperature T3<G, the wind speed of the fan remains unchanged; when G≤ambient temperature T4-condenser temperature T3<K, the wind speed is increased by one level; when the ambient temperature T4-condenser temperature T3≥K, the wind speed of the fan is increased by two levels.

[0015] Preferably, when the ambient temperature T4-condenser temperature T3<I, and the exhaust superheat degree is<L, the wind speed of the fan remains unchanged until the exhaust superheat degree is ≥N, at which time the wind speed of the fan can be reduced.

[0016] Preferably, when the ambient temperature T4-the condenser temperature T3<I, the ambient temperature T4≥0°C, and the condenser temperature T3<0°C, the wind speed of the fan remains unchanged.

[0017] The beneficial effects of the technical solution of the present invention are: improving the control of the fan of the multi-split air conditioner in the heating mode, from the determination of the initial wind speed to the adjustment of the subsequent wind speed, both of which can avoid rapid frosting caused by excessive fan speed; and controlling the air conditioner frosting from multiple aspects such as exhaust superheat, condensing pressure, and condenser temperature, thereby improving the precise heat exchange of the air conditioner condenser, ensuring the stable operation of the air conditioner while improving the heating comfort and energy saving and consumption reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram showing the difference between Scheme 1 and Scheme 2;

[0019] Figure 2 This is the control diagram of Scheme 2;

[0020] Figure 3 Schematic diagram of the fan gear control based on the temperature difference between the ambient temperature T4 and the condenser temperature T3. DETAILED DESCRIPTION

[0021] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0022] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0023] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more, unless otherwise clearly specified.

[0024] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0026] The following embodiment is a method for controlling an outdoor fan of a multi-split air conditioner in heating mode.

[0027] Example

[0028] like Figure 1 A method for accurately controlling the outdoor fan of a multi-split air conditioner is shown. The specific control of the fan is as follows:

[0029] Step 1) determining the initial gear position of the outdoor fan;

[0030] Step 2) The outdoor fan selects a control scheme according to the ambient temperature;

[0031] Step 3) When the ambient temperature T4>A, the outdoor fan selects option 1 to control the fan gear through the condenser temperature and the condensing pressure; when the ambient temperature T4<B, the fan selects option 2 to control the fan gear through the temperature difference between the ambient temperature T4 and the condenser temperature T3; when the ambient temperature T4 is between A and B, the outdoor fan maintains the initial gear operation. Among them, when the ambient temperature T4>A, it means that the ambient temperature is relatively high and the air conditioner is not prone to frost, so the condenser temperature and condensing pressure are used to accurately control the fan gear; when the ambient temperature T4<B, it means that the ambient temperature is relatively low and the probability of frosting the air conditioner is relatively high, and frosting of the air conditioner will greatly affect the air conditioning pressure, so the ambient temperature T4 and the condenser temperature T3 are used to accurately control the fan gear to reduce the impact of the ambient temperature on the air conditioner. In this way, the fan gear can be controlled more accurately to reduce the impact of the ambient temperature on the air conditioner. Figure 1As shown, in this embodiment, A is 4°C and B is 2°C, that is, when the ambient temperature T4>4°C, solution 1 is selected; when the ambient temperature T4<2°C, solution 2 is selected.

[0032] In this embodiment, in step 1), the initial wind speed of the fan is determined by the ambient temperature T4 and the operating capacity of the outdoor unit. Since the control method is to control the outdoor fan of the multi-split air conditioner, when starting the multi-split air conditioner, the user sometimes does not start all the outdoor fans at once, and the actual operating capacity of the outdoor unit of the multi-split air conditioner is small, and if the gear of the fan is constant each time it is started, and the outdoor temperature is always changing, it will not only affect the cooling or heating effect of the multi-split air conditioner, but also increase the energy consumption of the multi-split air conditioner, and the power consumption is the largest at the moment of starting the air conditioner. Therefore, through the above conditions, the initial gear of the fan is more flexibly controlled, and the power consumption of the multi-split air conditioner is lower, the startup is more stable, and the adjustment is more accurate. Further, the specific way to determine the initial wind speed is: the lower the ambient temperature T4, the larger the initial wind speed, and the larger the operating capacity of the outdoor unit, the larger the initial wind speed. In this way, the control of the fan by the multi-split air conditioner is more accurate, and the cooling or heating effect of the multi-split air conditioner can be further improved.

[0033] In this embodiment, the specific control scheme of scheme 1 described in step 3) is: after the fan runs at the initial wind speed for M minutes, when the condenser temperature T3≥C and the condensing pressure≤D, the wind speed of the fan is raised by one level; when the condenser temperature T3≥E and the condensing pressure≥F, the wind speed of the fan is lowered by one level; when the condenser temperature T3<G and the condensing pressure<F, the wind speed of the fan is raised by one level; under other conditions, the wind speed of the fan remains unchanged. Among them, when and the condensing pressure≤D, it means that the condensing pressure in the air conditioner is small, and the refrigerant in the air conditioner is in liquid state. Therefore, in order to ensure the heat exchange efficiency and stable operation of the air conditioner, it is necessary to increase the wind speed to accelerate the heat exchange; when the condensing pressure≥F, it means that the condensing pressure in the air conditioner is too large. Therefore, in order to ensure the heat exchange efficiency and stable operation of the air conditioner, it is necessary to lower the wind speed; when the condenser temperature T3<G and the condensing pressure<F, the condensation may frost in this state, so the fan gear remains unchanged to prevent the air conditioner from frosting and ensure the stable operation of the air conditioner.

[0034] In this embodiment, Figure 2As shown, the specific control scheme of the second scheme described in step 3) is: after the fan runs at the initial wind speed for M minutes, if the temperature value of the ambient temperature T4 is always greater than H within the M minutes that the fan runs at the initial wind speed, the gear of the fan is controlled by the temperature difference between the ambient temperature T4 and the condenser temperature T3; otherwise, the fan continues to run at the initial gear. In this way, it can be determined that the ambient temperature has an upward trend within the M minutes of air-conditioning operation. Therefore, the use of ambient temperature T4 and condenser temperature T3 can accurately control the fan and adjust the air-conditioning operation to ensure stable operation of the air-conditioning. In this embodiment, Figure 2 As shown, H is -5°C, that is, if the temperature value of the ambient temperature T4 is always greater than -5°C within 3 minutes when the fan runs at the initial wind speed, the gear position of the fan is controlled by the temperature difference between the ambient temperature T4 and the condenser temperature T3, otherwise the fan runs at the initial wind speed.

[0035] In this embodiment, Figure 3 As shown, the specific process of controlling the gear of the fan by the temperature difference between the ambient temperature T4 and the condenser temperature T3 is: when the ambient temperature T4-condenser temperature T3<I, the wind gear of the fan is reduced by one level; when I≤ambient temperature T4-condenser temperature T3<G, the wind gear of the fan remains unchanged; when G≤ambient temperature T4-condenser temperature T3<K, the wind gear is increased by one level; when the ambient temperature T4-condenser temperature T3≥K, the wind gear of the fan is increased by two levels. In this way, the air conditioner can be prevented from frosting and the fan can be controlled more accurately. In this embodiment, Figure 3 As shown, I is 3°C, G is 5°C, and K is 8°C, that is, when the ambient temperature T4-condenser temperature T3 is less than 3°C, the wind speed of the fan is reduced by one level; when 3°C≤ambient temperature T4-condenser temperature T3<5°C, the wind speed of the fan remains unchanged; when 5°C≤ambient temperature T4-condenser temperature T3<8°C, the wind speed is increased by one level; when the ambient temperature T4-condenser temperature T3≥8°C, the wind speed of the fan is increased by two levels.

[0036] In this embodiment, when the ambient temperature T4-condenser temperature T3<I, and the exhaust superheat degree is<L, the wind speed of the fan remains unchanged until the exhaust superheat degree is ≥N, and then the gear can be downgraded. When the ambient temperature T4-condenser temperature T3<I, and the exhaust superheat degree is<L, the air conditioner determines that frost may occur, so the fan gear remains unchanged to make the air conditioner run stably. In this embodiment, L is 11℃ and N is 15℃.

[0037] In this embodiment, when the ambient temperature T4-condenser temperature T3<I, the ambient temperature T4≥0℃, and the condenser temperature T3<0℃, the air conditioner may be frosted, so the windshield of the fan remains unchanged to ensure stable operation of the air conditioner.

[0038] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0039] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A method for accurately controlling an outdoor fan of a multi-split air conditioner, characterized in that: In heating mode, the specific control of the fan is as follows: Step 1) Determine the initial gear position of the outdoor fan; Step 2) The outdoor fan selects a control scheme according to the ambient temperature T4; Step 3) When the ambient temperature T4>A, the fan selection scheme 1 controls the fan gear position through the condenser temperature T3 and the condensing pressure; When the ambient temperature T4 is less than B, the fan selects the second scheme to control the fan gear position by the temperature difference between the ambient temperature T4 and the condenser temperature T3; wherein, the fan selects the second scheme to control the fan gear position; the specific control scheme of the second scheme is: after the fan runs at the initial wind gear for M minutes, if the temperature value of the ambient temperature T4 is always greater than H within the M minutes when the fan runs at the initial wind gear, the fan gear position is controlled by the temperature difference between the ambient temperature T4 and the condenser temperature T3; otherwise, the fan continues to run at the initial gear; When the ambient temperature T4 is between A and B, the outdoor fan maintains the initial gear operation.

2. A multi-split air conditioner outdoor fan precise control method according to claim 1, characterized in that: In step 1), the initial wind speed of the fan is determined by the ambient temperature T4 and the operating capacity of the outdoor unit.

3. A multi-split air conditioner outdoor fan precise control method according to claim 2, characterized in that: The specific method for determining the initial wind speed is: the lower the ambient temperature T4, the larger the initial wind speed; the larger the operating capacity of the outdoor unit, the larger the initial wind speed.

4. A multi-split air conditioner outdoor fan precise control method according to claim 1, characterized in that: The specific control scheme of scheme 1 described in step 3) is: after the fan runs at the initial wind speed for M minutes, when the condenser temperature T3 ≥ C and the condensing pressure ≤ D, the wind speed of the fan is increased by one level; when the condenser temperature T3 ≥ E and the condensing pressure ≥ F, the wind speed of the fan is decreased by one level; when the condenser temperature T3 < G and the condensing pressure < F, the wind speed of the fan is increased by one level; under other conditions, the wind speed of the fan remains unchanged.

5. A multi-split air conditioner outdoor fan precise control method according to claim 1, characterized in that: The specific process of controlling the gear of the fan by the temperature difference between the ambient temperature T4 and the condenser temperature T3 is as follows: when the ambient temperature T4-condenser temperature T3<I, the wind speed of the fan is reduced by one level; when I≤ambient temperature T4-condenser temperature T3<G, the wind speed of the fan remains unchanged; when G≤ambient temperature T4-condenser temperature T3<K, the wind speed is increased by one level; when the ambient temperature T4-condenser temperature T3≥K, the wind speed of the fan is increased by two levels.

6. A multi-split air conditioner outdoor fan precise control method according to claim 5, characterized in that: When the ambient temperature T4-condenser temperature T3<I, and the exhaust superheat degree<L, the wind speed of the fan remains unchanged until the exhaust superheat degree ≥N, at which time it can be downshifted.

7. A multi-split air conditioner outdoor fan precise control method according to claim 5, characterized in that: When the ambient temperature T4-condenser temperature T3<I, the ambient temperature T4≥0℃, and the condenser temperature T3<0℃, the wind speed of the fan remains unchanged.

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