Heat pump air conditioning system with fan rotating speed control function

Abstract

The invention relates to a heat pump air-conditioning system with a fan rotating speed control function, which is characterized in that the initial fan rotating speed is preliminarily corrected by monitoring ambient air pressure and air duct air pressure in real time, the air pressure difference between the ambient air pressure and the air duct air pressure is combined to judge the clockwise and counterclockwise wind relationship between natural wind and a fan, and the fan rotating speed is further dynamically corrected; finally, precise self-adaptive control over the fan rotating speed is achieved, the problems that traditional fixed rotating speed control is insufficient in heat exchange amount in a high-altitude area, energy consumption is wasted in the downwind process, and the capacity is reduced in the upwind process are effectively solved, the system energy efficiency, operation stability and environmental adaptability are remarkably improved, meanwhile, only a conventional air pressure sensor is needed, and the cost is reduced. The system has the advantages of low cost and high reliability.

Description

Technical Field

[0001] The present invention relates to the field of heat pump air conditioners, and in particular to a heat pump air conditioner system with fan speed control. Background Art

[0002] In a heat pump air conditioning system, since the outdoor heat exchanger needs to use air to exchange heat with the refrigerant in its pipes, a fan is usually installed on one side to force air supply or exhaust, significantly increasing the air flow rate, breaking the limitations of the air boundary layer during natural convection, and thus accelerating the heat transfer rate.

[0003] At present, the adjustment of fan speed is designed and adjusted in the laboratory based on the absence of natural wind, and only the compressor frequency, that is, the actual heat output of the compressor, is used to determine the fan speed; however, in actual use and operation, it is also necessary to consider the impact of the external environment on the heat exchange process of the outdoor heat exchanger. For example, the direction of the external natural wind may change at any time. Sometimes the natural wind and the fan's air outlet direction are the same, and sometimes the natural wind and the fan's air outlet direction are opposite; in addition, due to the altitude of the external environment where the outdoor heat exchanger is located, it will also directly affect the air content of the external environment, and thus also affect the heat exchange process between the outdoor heat exchanger and the external air.

[0004] Therefore, there is an urgent need to propose a heat pump air conditioning system that can solve the above problems. Summary of the Invention

[0005] Based on this, the purpose of the present invention is to overcome the defects or shortcomings of the prior art and provide a heat pump air conditioning system with fan speed control.

[0006] A heat pump air conditioning system with fan speed control includes a compressor, a reversing four-way valve, an indoor heat exchanger, a throttling assembly and an outdoor heat exchanger connected in sequence by a refrigerant circulation pipeline, the compressor and the reversing four-way valve are connected; it also includes an air duct and a fan arranged in the air duct, the inlet and outlet of the air duct are both connected to the external environment, the fan can drive the external air to flow in the air duct when it is working, and the outdoor heat exchanger is arranged in the air duct; it also includes a device for obtaining the actual ambient air pressure P r Ambient air pressure sensor, and used to obtain the duct air pressure P f The air duct pressure sensor further comprises a controller connected to the compressor, the fan, the ambient air pressure sensor and the air duct pressure sensor; wherein the controller comprises a compressor frequency acquisition unit, a fan initial speed calculation unit, an air pressure acquisition unit and a fan target speed calculation unit;

[0007] The compressor frequency acquisition unit is used to acquire the compressor frequency F of the system;

[0008] The fan initial speed calculation unit is used to determine the fan initial speed n0 according to the interval of the compressor frequency F;

[0009] The air pressure acquisition unit is used to obtain the actual ambient air pressure P r and duct pressure P f ;

[0010] The fan target speed calculation unit is used to calculate the target speed of the fan according to the actual ambient pressure P r Calculate the actual environment altitude h, and calculate the actual environment air density ρ based on the actual environment altitude h, combined with the actual environment pressure P r , air duct pressure P f The fan initial speed n0 is preliminarily corrected by the actual ambient air density ρ to obtain the fan target speed n.

[0011] Compared with the existing technology, the initial speed of the fan is corrected by real-time monitoring of the ambient air pressure and the air duct pressure, thereby achieving precise adaptive control of the fan speed, effectively solving the problem of insufficient heat exchange in high-altitude areas caused by traditional fixed speed control.

[0012] In one embodiment, the fan target speed calculation unit calculates the actual ambient pressure P according to the obtained r Calculate the actual environment altitude h, including:

[0013]

[0014] Among them, P r0 is the standard air pressure at sea level.

[0015] In one embodiment, the fan target speed calculation unit calculates the actual ambient air density ρ according to the actual ambient altitude h, including:

[0016]

[0017] Where ρ0 is the standard air density at sea level.

[0018] In one embodiment, the fan target speed calculation unit combines the actual ambient pressure P r , air duct pressure P f The fan initial speed n0 is preliminarily corrected by the actual ambient air density ρ to obtain the fan target speed n, including:

[0019]

[0020] Among them, n0 is the initial speed of the fan.

[0021] In one embodiment, it further includes an air pressure difference determination unit and a fan target speed correction unit;

[0022] The air pressure difference judgment unit is used to obtain the actual ambient air pressure P r and duct pressure P f , calculate the actual ambient air pressure P r and duct pressure P f The difference △P between them is used to determine the size relationship between the difference △P and the difference threshold △P0;

[0023] The fan target speed correction unit is used to perform a secondary correction on the fan target speed n according to the relationship between the difference ΔP and the difference threshold ΔP0 to obtain the fan correction speed n x .

[0024] In one embodiment, the target speed n of the fan is corrected twice according to the relationship between the difference ΔP and the difference threshold ΔP0 to obtain the corrected speed n of the fan. x ,include:

[0025] If △P<△P0, it is determined that the natural wind direction at the current moment is opposite to the wind direction of the fan, then n x =n×α, where α is the first wind direction parameter, and its value is greater than 1;

[0026] If △P>△P0, it is determined that the natural wind direction at the current moment is the same as the wind direction of the fan, then n x =n×β, where β is the second wind direction parameter, and its value is less than 1;

[0027] The difference threshold ΔP0 is a calibration value when the fan is running under no-wind conditions, which is measured experimentally.

[0028] In one embodiment, determining the initial fan speed n0 according to the interval in which the compressor frequency F is located includes:

[0029] When F≤30Hz, the initial speed of the fan n0 is 550rpm / min;

[0030] When 30Hz<F≤50Hz, the initial speed n0 of the fan is 650rpm / min;

[0031] When 50Hz<F≤60Hz, the initial speed n0 of the fan is 750rpm / min;

[0032] When 60Hz<F≤75Hz, the initial speed n0 of the fan is 850rpm / min;

[0033] When 75Hz<F≤85Hz, the initial speed n0 of the fan is 900rpm / min;

[0034] When 85 Hz < F, the initial speed n0 of the fan is 950 rpm / min.

[0035] In one embodiment, the sea level standard pressure P r0 The value is 101325Pa; the sea level standard air density ρ0 is 1.225kg / m 3 .

[0036] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of the structure of the heat pump air conditioning system with fan speed control of the present invention;

[0038] Figure 2 A flow chart of a method for obtaining a target fan speed in a heat pump air conditioning system of the present invention;

[0039] Figure 3 This is a flow chart of a method for obtaining a corrected fan speed in a heat pump air conditioning system of the present invention. DETAILED DESCRIPTION

[0040] The solution of the present invention is described in detail below with reference to the accompanying drawings.

[0041] like Figure 1 As shown, a heat pump air-conditioning system with fan speed control of the present invention includes a compressor 11, and a reversing four-way valve 12, an indoor heat exchanger 13, a throttling component 14 and an outdoor heat exchanger 15 connected in sequence by a refrigerant circulation pipeline, and the compressor 11 is connected to the reversing four-way valve 12.

[0042] Furthermore, it also includes an air duct 16 and a fan 17 arranged in the air duct 16. The inlet and outlet of the air duct 16 are both connected to the external environment. When the fan 17 is working, it can drive the external air to flow from its leeward side to its outlet side; the outdoor heat exchanger 15 is arranged in the air duct 16, and it is located on the leeward side of the fan 17.

[0043] Furthermore, it also includes an air pressure sensor group, which includes an ambient air pressure sensor 21 set in the external environment where the outdoor heat exchanger 15 is located, and an air duct air pressure sensor 22 set in the air duct 16; wherein the ambient air pressure sensor 21 is used to obtain the actual ambient air pressure P r The air duct pressure sensor 22 is used to obtain the air pressure P in the air duct 16. f .

[0044] Furthermore, a controller is included, which is connected to the compressor 11 , the fan 17 , the ambient air pressure sensor 21 and the air duct air pressure sensor 22 .

[0045] like Figure 2 As shown, the controller includes a compressor frequency acquisition unit, a fan initial speed calculation unit, an air pressure acquisition unit and a fan target speed calculation unit;

[0046] The compressor frequency acquisition unit is used to acquire the compressor frequency F of the system;

[0047] The fan initial speed calculation unit is used to determine the fan initial speed n0 according to the interval of the compressor frequency F;

[0048] The air pressure acquisition unit is used to obtain the actual ambient air pressure P r and duct pressure P f ;

[0049] The fan target speed calculation unit is used to calculate the target speed of the fan according to the actual ambient pressure P r Calculate the actual environment altitude h, and calculate the actual environment air density ρ based on the actual environment altitude h, combined with the actual environment pressure P r , air duct pressure P f The fan initial speed n0 is preliminarily corrected by the actual ambient air density ρ to obtain the fan target speed n.

[0050] Specifically, the target speed of the fan is determined based on the actual ambient pressure P r Calculate the actual environment altitude h, as shown in the following formula:

[0051]

[0052] Among them, P r0 It is the standard atmospheric pressure at sea level, which is 101325Pa.

[0053] Specifically, the actual environment air density ρ is calculated according to the actual environment altitude h, as expressed by the following formula:

[0054]

[0055] Where ρ0 is the standard air density at sea level, which is 1.225 kg / m 3 .

[0056] Specifically, combined with the actual ambient air pressure P r , air duct pressure P f The fan target speed n is calculated based on the actual ambient air density ρ, as shown in the following formula:

[0057]

[0058] Wherein, n0 is the initial speed of the fan, and the initial speed of the fan n0 is determined according to the interval in which the compressor frequency F is located, including:

[0059] When F≤30Hz, the initial speed n0 of the fan is 550rpm / min;

[0060] When 30Hz<F≤50Hz, the initial speed n0 of the fan is 650rpm / min;

[0061] When 50Hz<F≤60Hz, the initial speed n0 of the fan is 750rpm / min;

[0062] When 60Hz<F≤75Hz, the initial speed n0 of the fan is 850rpm / min;

[0063] When 75Hz<F≤85Hz, the initial speed n0 of the fan is 900rpm / min;

[0064] When 85 Hz < F, the initial speed n0 of the fan is 950 rpm / min.

[0065] like Figure 3 As shown, further, taking into account the influence of the relationship between the external natural wind and the airflow direction of the fan 17 on the fan speed: when the external natural wind direction is the same as the airflow direction of the fan 17, the fan speed needs to be reduced accordingly; when the external natural wind direction is opposite to the airflow direction of the fan 17, the fan speed needs to be reduced accordingly; it also includes an air pressure difference judgment unit and a fan target speed correction unit.

[0066] The air pressure difference judgment unit is used to obtain the actual ambient air pressure P r and duct pressure P f , calculate the actual ambient air pressure P r and duct pressure P f The difference △P between them is used to determine the size relationship between the difference △P and the difference threshold △P0;

[0067] The fan target speed correction unit is used to perform a secondary correction on the fan target speed n according to the relationship between the difference ΔP and the difference threshold ΔP0 to obtain the fan correction speed n x .

[0068] Specifically, the fan target speed correction unit performs a secondary correction on the fan target speed n according to the relationship between the difference ΔP and the difference threshold ΔP0 to obtain the fan correction speed nx ,include:

[0069] If △P<△P0, it is determined that the natural wind direction at the current moment is opposite to the wind direction of the fan, then n x =n×α, where α is the first wind direction parameter, and its value is greater than 1;

[0070] If △P>△P0, it is determined that the natural wind direction at the current moment is the same as the wind direction of the fan, then n x =n×β, where β is the second wind direction parameter, and its value is less than 1;

[0071] The difference threshold ΔP0 is a calibration value when the fan is running under no-wind conditions, which is measured experimentally.

[0072] Compared with the existing technology, the present invention makes a preliminary correction to the initial speed of the fan by real-time monitoring of the ambient air pressure and the air duct pressure, and judges the relationship between the natural wind and the headwind of the fan in combination with the air pressure difference between the ambient air pressure and the air duct pressure, and further makes dynamic corrections to it, and finally realizes precise adaptive control of the fan speed, effectively solving the problems of insufficient heat exchange in high-altitude areas, energy waste in the tailwind and reduced capacity in the headwind caused by traditional fixed speed control, and significantly improves the system energy efficiency, operation stability and environmental adaptability. At the same time, it can be achieved with only a conventional air pressure sensor, and has the advantages of low cost and high reliability.

[0073] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present application. The singular forms of "a", "said" and "the" used in the embodiments of the present application and the claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that, unless otherwise specified, "multiple" refers to two or more; the terms "first", "second", "third", etc. are only used to distinguish, and are not used to describe a specific order or sequence, nor can they be understood to indicate or imply relative importance. The term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items. When the above description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. In the description of the present application, for those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0074] The above-described embodiments merely illustrate several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, and all such variations and improvements fall within the scope of protection of the present invention.

Claims

1. A heat pump air conditioning system with fan speed control, comprising a compressor, a reversing four-way valve, an indoor heat exchanger, a throttling assembly, and an outdoor heat exchanger connected in sequence by a refrigerant circulation pipeline, wherein the compressor is connected to the reversing four-way valve; further comprising an air duct, and a fan disposed in the air duct, wherein the inlet and outlet of the air duct are both connected to the external environment, and when the fan is in operation, it can drive external air to flow in the air duct, and the outdoor heat exchanger is disposed in the air duct; further comprising a device for obtaining the actual ambient air pressure P r Ambient air pressure sensor, and used to obtain the duct air pressure P f The air duct pressure sensor further comprises a controller connected to the compressor, the fan, the ambient air pressure sensor and the air duct pressure sensor, characterized in that: The controller includes a compressor frequency acquisition unit, a fan initial speed calculation unit, an air pressure acquisition unit and a fan target speed calculation unit; The compressor frequency acquisition unit is used to acquire the compressor frequency F of the system; The fan initial speed calculation unit is used to determine the fan initial speed n0 according to the interval of the compressor frequency F; The air pressure acquisition unit is used to obtain the actual ambient air pressure P r and duct pressure P f ; The fan target speed calculation unit is used to calculate the target speed of the fan according to the actual ambient pressure P r Calculate the actual environment altitude h, and calculate the actual environment air density ρ based on the actual environment altitude h, combined with the actual environment pressure P r , air duct pressure P f The fan initial speed n0 is preliminarily corrected by the actual ambient air density ρ to obtain the fan target speed n.

2. The heat pump air conditioning system with fan speed control according to claim 1, characterized in that: The fan target speed calculation unit calculates the actual ambient air pressure P r Calculate the actual environment altitude h, including: Among them, P r0 is the standard air pressure at sea level.

3. The heat pump air conditioning system with fan speed control according to claim 2, characterized in that: The fan target speed calculation unit calculates the actual ambient air density ρ according to the actual ambient altitude h, including: Where ρ0 is the standard air density at sea level.

4. The heat pump air conditioning system with fan speed control according to claim 3, characterized in that: The fan target speed calculation unit combines the actual ambient air pressure P r , air duct pressure P f The fan initial speed n0 is preliminarily corrected by the actual ambient air density ρ to obtain the fan target speed n, including: Among them, n0 is the initial speed of the fan.

5. The heat pump air conditioning system with fan speed control according to claim 1 or 4, characterized in that: It also includes an air pressure difference judgment unit and a fan target speed correction unit; The air pressure difference judgment unit is used to obtain the actual ambient air pressure P r and duct pressure P f , calculate the actual ambient air pressure P r and duct pressure P f The difference △P between them is used to determine the size relationship between the difference △P and the difference threshold △P0; The fan target speed correction unit is used to perform a secondary correction on the fan target speed n according to the relationship between the difference ΔP and the difference threshold ΔP0 to obtain the fan correction speed n x .

6. The heat pump air conditioning system with fan speed control according to claim 5, characterized in that: According to the relationship between the difference △P and the difference threshold △P0, the fan target speed n is corrected twice to obtain the fan correction speed n x ,include: If △P<△P0, it is determined that the natural wind direction at the current moment is opposite to the wind direction of the fan, then n x =n×α, where α is the first wind direction parameter, and its value is greater than 1; If △P>△P0, it is determined that the natural wind direction at the current moment is the same as the wind direction of the fan, then n x =n×β, where β is the second wind direction parameter, and its value is less than 1; The difference threshold ΔP0 is a calibration value when the fan is running under no-wind conditions, which is measured experimentally.

7. The heat pump air conditioning system with fan speed control according to claim 6, characterized in that: Determining the initial fan speed n0 according to the range of the compressor frequency F includes: When F≤30Hz, the initial speed n0 of the fan is 550rpm / min; When 30Hz<F≤50Hz, the initial speed n0 of the fan is 650rpm / min; When 50Hz<F≤60Hz, the initial speed n0 of the fan is 750rpm / min; When 60Hz<F≤75Hz, the initial speed n0 of the fan is 850rpm / min; When 75Hz<F≤85Hz, the initial speed n0 of the fan is 900rpm / min; When 85 Hz < F, the initial speed n0 of the fan is 950 rpm / min.

8. The heat pump air conditioning system with fan speed control according to claim 7, characterized in that: The standard sea level pressure P r0 The value is 101325Pa; the sea level standard air density ρ0 is 1.225kg / m 3 .

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