Fan rotating speed control method and heat pump system with same

Abstract

The invention relates to a heat pump system with a fan rotating speed control function. The heat pump system comprises a fan rotating speed obtaining unit used for obtaining the fan rotating speed V at the current moment, a return air superheat degree calculating unit and a fan rotating speed adjusting unit used for controlling the fan rotating speed V according to the interval where the return air superheat degree Tsh and the environment temperature Tr are located. The change direction of the fan rotating speed V can be preliminarily determined according to the return air superheat degree, then the change rate of the fan rotating speed V is controlled according to the environment temperature, the heat exchange efficiency of the heat exchanger is fully exerted, energy saving maximization is achieved, and meanwhile the stability and safety of the unit are guaranteed.

Description

Technical Field

[0001] This invention relates to the field of heat pump technology, and in particular to a fan speed control method and a heat pump system having the control method. Background Technology

[0002] Air source heat pump pool units are high-efficiency and energy-saving hot water supply equipment, mainly used for heating and temperature control of pool water. They absorb heat from the ambient air and transfer it to the pool water through a compressor and heat exchange system, achieving energy-saving and environmentally friendly heating effects. These units are suitable for various indoor and outdoor pools, especially in areas with variable climates, and can adapt to different ambient temperatures to provide users with a stable supply of hot water.

[0003] Existing heat pump system fan speed control methods are usually based on a single ambient temperature variable or a fixed speed mode. For example, the fan speed is adjusted only according to the ambient temperature. For instance, the speed is increased at high temperatures to enhance heat dissipation, and the speed is reduced at low temperatures to reduce heat loss. In addition, some units use a fixed fan speed, and the fan always runs at a constant speed regardless of changes in ambient temperature or internal system conditions.

[0004] Single-mode ambient temperature control ignores key system parameters such as return gas superheat, resulting in the fan speed failing to accurately match the actual heat load demand. For example, under high ambient temperature conditions, insufficient fan speed may trigger compressor overheat protection, leading to abnormal unit operation and poor stability. Under low ambient temperature conditions, excessively low return gas temperature can easily cause abnormal lubricating oil viscosity, increasing compressor wear and even leading to the risk of liquid slugging. In addition, fixed speed or single-variable control cannot dynamically optimize heat exchange efficiency, resulting in energy waste or reduced heating effect, affecting the overall performance of the unit. Summary of the Invention

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

[0006] A heat pump system with fan speed control includes a compressor, a condenser, a throttling component, and an evaporator connected in sequence by a refrigerant circulation pipeline, and a fan disposed on one side of the evaporator; it also includes a first temperature sensor for obtaining the ambient temperature Tr, a second temperature sensor for obtaining the return gas temperature Ti, and a pressure sensor for obtaining the return gas pressure and thus the saturation temperature Tsat; and a controller electrically connected to the first temperature sensor, the second temperature sensor, the pressure sensor, the compressor, and the fan; the controller includes a fan speed acquisition unit, a return gas superheat calculation unit, and a fan speed adjustment unit;

[0007] The fan speed acquisition unit is used to acquire the fan speed V at the current moment;

[0008] The return gas superheat calculation unit is used to obtain the return gas temperature Ti and saturation temperature Tsat at the current moment, calculate the difference between the return gas temperature Ti and saturation temperature Tsat, and obtain the return gas superheat ΔTsh.

[0009] The fan speed adjustment unit is used to adjust the fan speed V at the current moment according to the range of the return gas superheat ΔTsh.

[0010] Compared with existing technologies, the heat pump system with fan speed control described in this invention can initially determine the direction of change of fan speed V based on the return gas superheat, fully utilize the heat exchange efficiency of the heat exchanger, maximize energy saving, and at the same time ensure the stability and safety of the unit.

[0011] In one embodiment, controlling the fan speed V according to the range of the return gas superheat ΔTsh includes:

[0012] When △Tsh < △Tsh_min, control the fan speed to increase;

[0013] When △Tsh_min≤△Tsh≤△Tsh_max, control the fan to maintain the current speed;

[0014] When △Tsh>△Tsh_max, control the fan speed to decrease;

[0015] Wherein, △Tsh_min is the low threshold of return gas superheat, and △Tsh_max is the high threshold of return gas superheat; the low threshold of return gas superheat △Tsh_min ranges from △Tsh_min∈(0,2)℃; the high threshold of return gas superheat △Tsh_max ranges from △Tsh_max∈(10,15)℃.

[0016] In one embodiment, the fan speed regulation unit further includes acquiring the current ambient temperature Tr and determining the rate of change of the fan speed V based on the ambient temperature Tr.

[0017] In one embodiment, determining the rate of change of the fan speed V based on the ambient temperature Tr includes:

[0018] When △Tsh<△Tsh_min, if Tr<Tr_min, the fan speed V is controlled to increase by 3 rpm / s; if Tr_min≤Tr≤Tr_max, the fan speed V is controlled to increase by 1 rpm / s; if Tr>Tr_max, the fan speed V is controlled to increase by 1 rpm / 2s.

[0019] When △Tsh>△Tsh_max, if Tr<Tr_min, the fan speed V is controlled to decrease by 1rpm / 2s; if Tr_min≤Tr≤Tr_max, the fan speed V is controlled to decrease by 1rpm / s; if Tr>Tr_max, the fan speed V is controlled to decrease by 3rpm / s.

[0020] Wherein, Tr_min is the low threshold of ambient temperature, and Tr_max is the high threshold of ambient temperature. The low threshold Tr_min is 8℃, and the high threshold Tr_max is 35℃.

[0021] In one embodiment, the fan speed acquisition unit further includes acquiring the initial fan speed V0: acquiring the target operating frequency F of the compressor. target And according to the target operating frequency F target The initial speed V0 of the fan was calculated.

[0022] In one embodiment, based on the target operating frequency F target The initial speed V0 of the fan is calculated, specifically expressed by the following formula:

[0023] V0=K×F target ×10

[0024] Wherein, K is the determination coefficient for the initial speed of the fan, which is determined as follows: obtain the current ambient temperature Tr, determine the magnitude of the ambient temperature Tr, and determine the value of the determination coefficient K for the initial speed of the fan based on the determination result:

[0025] When Tr < Tr_min, the initial speed determination coefficient K of the fan is 1.2.

[0026] When Tr_min≤Tr≤Tr_max, the initial speed determination coefficient K of the fan is 1.

[0027] When Tr > Tr_max, the initial speed determination coefficient K of the fan is 0.8.

[0028] In addition, the present invention also provides a method for controlling the speed of a fan, comprising the following steps:

[0029] S10: Obtain the current fan speed V;

[0030] S20: Obtain the current return gas temperature Ti and saturation temperature Tsat, calculate the difference between the return gas temperature Ti and saturation temperature Tsat, and obtain the return gas superheat ΔTsh.

[0031] S30: Adjust the fan speed V at the current moment according to the range of the return gas superheat △Tsh, including:

[0032] When △Tsh < △Tsh_min, control the fan speed to increase;

[0033] When △Tsh_min≤△Tsh≤△Tsh_max, control the fan to maintain the current speed;

[0034] When △Tsh>△Tsh_max, control the fan speed to decrease;

[0035] Wherein, △Tsh_min is the low threshold of return gas superheat, and △Tsh_max is the high threshold of return gas superheat; the low threshold of return gas superheat △Tsh_min ranges from △Tsh_min∈(0,2)℃; the high threshold of return gas superheat △Tsh_max ranges from △Tsh_max∈(10,15)℃.

[0036] In one embodiment, step S30 further includes obtaining the current ambient temperature Tr and further determining the rate of change of the fan speed V based on the ambient temperature Tr.

[0037] In one embodiment, determining the rate of change of the fan speed V based on the ambient temperature Tr includes:

[0038] When △Tsh<△Tsh_min, if Tr<Tr_min, the fan speed V is controlled to increase by 3 rpm / s; if Tr_min≤Tr≤Tr_max, the fan speed V is controlled to increase by 1 rpm / s; if Tr>Tr_max, the fan speed V is controlled to increase by 1 rpm / 2s.

[0039] When △Tsh>△Tsh_max, if Tr<Tr_min, the fan speed V is controlled to decrease by 1rpm / 2s; if Tr_min≤Tr≤Tr_max, the fan speed V is controlled to decrease by 1rpm / s; if Tr>Tr_max, the fan speed V is controlled to decrease by 3rpm / s.

[0040] Wherein, Tr_min is the low threshold of ambient temperature, and Tr_max is the high threshold of ambient temperature. The low threshold Tr_min is 8℃, and the high threshold Tr_max is 35℃.

[0041] In one embodiment, step S10 further includes: according to the compressor's target operating frequency F target The initial speed V0 of the fan is calculated, specifically expressed by the following formula:

[0042] V0=K×F target ×10

[0043] Wherein, K is the determination coefficient for the initial speed of the fan, which is determined as follows: obtain the current ambient temperature Tr, determine the magnitude of the ambient temperature Tr, and determine the value of the determination coefficient K for the initial speed of the fan based on the determination result:

[0044] When Tr < Tr_min, the initial speed determination coefficient K of the fan is 1.2.

[0045] When Tr_min≤Tr≤Tr_max, the initial speed determination coefficient K of the fan is 1.

[0046] When Tr > Tr_max, the initial speed determination coefficient K of the fan is 0.8.

[0047] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the structure of the heat pump system provided by the present invention;

[0049] Figure 2 A schematic diagram of the component structure included in the controller provided by the present invention;

[0050] Figure 3 The flowchart of the fan speed control method provided by the present invention. Detailed Implementation

[0051] The present invention will now be described in detail with reference to the accompanying drawings.

[0052] like Figure 1 As shown, a heat pump system with fan speed control according to the present invention includes a compressor 11, a condenser 12, a throttling component 13 and an evaporator 14 connected in sequence by a refrigerant circulation pipeline, and a fan 15 disposed near the evaporator 14.

[0053] Specifically, the compressor 11 can be either a fixed-frequency compressor 11 or a variable-frequency compressor 11; the condenser 12 is a water source heat exchanger, through which the refrigerant flows from the compressor 11 and exchanges heat with the external water; the throttling component 13 is an electronic expansion valve; and the evaporator 14 is an air source heat exchanger, through which the refrigerant flows from the throttling component 13 and exchanges heat with the external air.

[0054] The heat pump system further includes a first temperature sensor 21 for detecting ambient temperature, a second temperature sensor 22 disposed on the return gas pipe of the compressor 11, and a pressure sensor 23 disposed on the return gas pipe of the compressor 11.

[0055] Specifically, the location of the first temperature sensor 21 is not specifically limited in this invention, and it is only used to collect the ambient temperature of the external environment where the evaporator 14 is located to obtain the ambient temperature Tr; the second temperature sensor 22 is used to collect the return gas temperature of the compressor 11 to obtain the return gas temperature Ti; the pressure sensor 23 is used to collect the return gas pressure of the compressor 11, and obtain the corresponding saturation temperature Tsat under the return gas pressure by looking up a table according to the refrigerant type.

[0056] Specifically, it also includes a controller, and the first temperature sensor 21, the second temperature sensor 22, the pressure sensor 23, the compressor 11 and the fan 15 are electrically or communicatively connected to the controller.

[0057] like Figure 2 and Figure 3 As shown, the controller includes a fan speed acquisition unit 31, a return gas superheat calculation unit 32, and a fan speed adjustment unit 33.

[0058] The fan speed acquisition unit 31 is used to execute step S10: acquire the fan speed V at the current moment;

[0059] The fan initial speed calculation unit 31 also includes obtaining the fan initial speed V0: obtaining the compressor target operating frequency F. target And according to the target operating frequency F target The initial speed V0 of the fan was calculated.

[0060] Specifically, according to the target operating frequency F target The initial speed V0 of the fan is calculated, specifically expressed by the following formula:

[0061] V0=K×F target ×10

[0062] Wherein, K is the determination coefficient for the initial speed of the fan, which is determined as follows: obtain the current ambient temperature Tr, determine the magnitude of the ambient temperature Tr, and determine the value of the determination coefficient K for the initial speed of the fan based on the determination result:

[0063] When Tr < Tr_min, the initial speed determination coefficient K of the fan is 1.2.

[0064] When Tr_min≤Tr≤Tr_max, the initial speed determination coefficient K of the fan is 1.

[0065] When Tr > Tr_max, the initial speed determination coefficient K of the fan is 0.8.

[0066] Specifically, Tr_min is the low threshold of ambient temperature, and Tr_max is the high threshold of ambient temperature. In this application, the low threshold Tr_min is 8°C, and the high threshold Tr_max is 35°C.

[0067] The return gas superheat calculation unit 32 is used to perform step S20: obtain the return gas temperature Ti and saturation temperature Tsat at the current moment, calculate the difference between the return gas temperature Ti and saturation temperature Tsat, and obtain the return gas superheat △Tsh.

[0068] Specifically, the return gas superheat ΔTsh is obtained by ΔTsh = Ti - Tsat.

[0069] The fan speed adjustment unit 33 is used to perform step S30: adjust the fan speed V at the current moment according to the range of the return gas superheat △Tsh.

[0070] Specifically, the fan speed V ranges from V∈(200,1500)rpm.

[0071] Specifically, controlling the fan speed V according to the range of the return gas superheat ΔTsh includes:

[0072] When △Tsh < △Tsh_min, control the fan speed to increase;

[0073] When △Tsh_min≤△Tsh≤△Tsh_max, control the fan to maintain the current speed;

[0074] When △Tsh > △Tsh_max, control the fan speed to decrease.

[0075] Specifically, △Tsh_min is the low threshold of return gas superheat, and △Tsh_max is the high threshold of return gas superheat. In this application, the low threshold of return gas superheat △Tsh_min ranges from △Tsh_min∈(0,2)℃; the high threshold of return gas superheat △Tsh_max ranges from △Tsh_max∈(10,15)℃.

[0076] Furthermore, the fan speed adjustment unit 33 also includes acquiring the current ambient temperature Tr and further determining the rate of change of the fan speed V based on the ambient temperature Tr.

[0077] Specifically, determining the rate of change of the fan speed V based on the ambient temperature Tr includes:

[0078] When △Tsh<△Tsh_min, if Tr<Tr_min, the fan speed V is controlled to increase by 3 rpm / s; if Tr_min≤Tr≤Tr_max, the fan speed V is controlled to increase by 1 rpm / s; if Tr>Tr_max, the fan speed V is controlled to increase by 1 rpm / 2s.

[0079] When △Tsh>△Tsh_max, if Tr<Tr_min, the fan speed V is controlled to decrease by 1rpm / 2s; if Tr_min≤Tr≤Tr_max, the fan speed V is controlled to decrease by 1rpm / s; if Tr>Tr_max, the fan speed V is controlled to decrease by 3rpm / s.

[0080] Furthermore, step S30 also includes: obtaining the current ambient temperature Tr, and further controlling the rate of change of the fan speed V based on the ambient temperature Tr.

[0081] Specifically, controlling the rate of change of the fan speed V based on the ambient temperature Tr includes:

[0082] When △Tsh<△Tsh_min, if Tr<Tr_min, the fan speed V is controlled to increase by 3 rpm / s; if Tr_min≤Tr≤Tr_max, the fan speed V is controlled to increase by 1 rpm / s; if Tr>Tr_max, the fan speed V is controlled to increase by 1 rpm / 2s.

[0083] When △Tsh>△Tsh_max, if Tr<Tr_min, the fan speed V is controlled to decrease by 1rpm / 2s; if Tr_min≤Tr≤Tr_max, the fan speed V is controlled to decrease by 1rpm / s; if Tr>Tr_max, the fan speed V is controlled to decrease by 3rpm / s.

[0084] Compared with the prior art, the present invention provides a heat pump system with fan speed control, which can initially determine the direction of change of fan speed V based on the return gas superheat, and then control the rate of change of fan speed V based on the ambient temperature, so as to give full play to the heat exchange efficiency of the heat exchanger, maximize energy saving, and at the same time ensure the stability and safety of the unit.

[0085] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of this application. The singular forms “a,” “the,” and “the” used in the embodiments and claims of this application 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; the terms “first,” “second,” “third,” etc., are used only to distinguish and not to describe a particular order or sequence, nor should they be construed as indicating or implying relative importance. The term “and / or” as used herein refers to and includes any or all possible combinations of one or more associated listed items. When the above description relates to drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. In the description of this application, those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0086] 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 these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A heat pump system with fan speed control, comprising a compressor, a condenser, a throttling component, and an evaporator connected in sequence by a refrigerant circulation pipeline, and a fan disposed on one side of the evaporator; further comprising a first temperature sensor for obtaining ambient temperature Tr, a second temperature sensor for obtaining return gas temperature Ti, and a pressure sensor for obtaining return gas pressure and thus saturation temperature Tsat; further comprising a controller electrically connected to the first temperature sensor, the second temperature sensor, the pressure sensor, the compressor, and the fan; characterized in that: The controller includes a fan speed acquisition unit, a return gas superheat calculation unit, and a fan speed adjustment unit; The fan speed acquisition unit is used to acquire the fan speed V at the current moment; The return gas superheat calculation unit is used to obtain the current return gas temperature Ti and saturation temperature Tsat, calculate the difference between the return gas temperature Ti and saturation temperature Tsat, and obtain the return gas superheat ΔTsh. The fan speed adjustment unit is used to adjust the fan speed V at the current moment according to the range of the return gas superheat ΔTsh.

2. The heat pump system with fan speed control according to claim 1, characterized in that, Controlling the fan speed V based on the range of the return gas superheat ΔTsh includes: When △Tsh < △Tsh_min, control the fan speed to increase; When △Tsh_min≤△Tsh≤△Tsh_max, control the fan to maintain the current speed; When △Tsh>△Tsh_max, control the fan speed to decrease; Wherein, △Tsh_min is the low threshold of return gas superheat, and △Tsh_max is the high threshold of return gas superheat; the low threshold of return gas superheat △Tsh_min ranges from △Tsh_min∈(0,2)℃; the high threshold of return gas superheat △Tsh_max ranges from △Tsh_max∈(10,15)℃.

3. The heat pump system with fan speed control according to claim 2, characterized in that: The fan speed regulation unit further includes acquiring the current ambient temperature Tr and determining the rate of change of the fan speed V based on the ambient temperature Tr.

4. The heat pump system with fan speed control according to claim 3, characterized in that, Determining the rate of change of the fan speed V based on the ambient temperature Tr includes: When △Tsh<△Tsh_min, if Tr<Tr_min, the fan speed V is controlled to increase by 3 rpm / s; if Tr_min≤Tr≤Tr_max, the fan speed V is controlled to increase by 1 rpm / s; if Tr>Tr_max, the fan speed V is controlled to increase by 1 rpm / 2s. When △Tsh>△Tsh_max, if Tr<Tr_min, the fan speed V is controlled to decrease by 1rpm / 2s; if Tr_min≤Tr≤Tr_max, the fan speed V is controlled to decrease by 1rpm / s; if Tr>Tr_max, the fan speed V is controlled to decrease by 3rpm / s. Wherein, Tr_min is the low threshold of ambient temperature, and Tr_max is the high threshold of ambient temperature. The low threshold Tr_min is 8℃, and the high threshold Tr_max is 35℃.

5. The heat pump system with fan speed control according to any one of claims 1 or 4, characterized in that, The fan speed acquisition unit also includes acquiring the initial fan speed V0 and the target operating frequency F of the compressor. target And according to the target operating frequency F target The initial speed V0 of the fan was calculated.

6. The heat pump system with fan speed control according to claim 5, characterized in that, According to the target operating frequency F target The initial speed V0 of the fan is calculated, specifically expressed by the following formula: V0=K×F target ×10 Wherein, K is the determination coefficient for the initial speed of the fan, which is determined as follows: obtain the current ambient temperature Tr, determine the magnitude of the ambient temperature Tr, and determine the value of the determination coefficient K for the initial speed of the fan based on the determination result: When Tr < Tr_min, the initial speed determination coefficient K of the fan is 1.

2. When Tr_min≤Tr≤Tr_max, the initial speed determination coefficient K of the fan is 1. When Tr > Tr_max, the initial speed determination coefficient K of the fan is 0.

8.

7. A method for controlling the speed of a fan, characterized in that, Includes the following steps: S10: Obtain the current fan speed V; S20: Obtain the current return gas temperature Ti and saturation temperature Tsat, calculate the difference between the return gas temperature Ti and saturation temperature Tsat, and obtain the return gas superheat ΔTsh. S30: Adjust the fan speed V at the current moment according to the range of the return gas superheat △Tsh, including: When △Tsh < △Tsh_min, control the fan speed to increase; When △Tsh_min≤△Tsh≤△Tsh_max, control the fan to maintain the current speed; When △Tsh>△Tsh_max, control the fan speed to decrease; Wherein, △Tsh_min is the low threshold of return gas superheat, and △Tsh_max is the high threshold of return gas superheat; the low threshold of return gas superheat △Tsh_min ranges from △Tsh_min∈(0,2)℃; the high threshold of return gas superheat △Tsh_max ranges from △Tsh_max∈(10,15)℃.

8. The fan speed control method according to claim 7, characterized in that: Step S30 also includes obtaining the current ambient temperature Tr and further determining the rate of change of the fan speed V based on the ambient temperature Tr.

9. The fan speed control method according to claim 8, characterized in that, Determining the rate of change of the fan speed V based on the ambient temperature Tr includes: When △Tsh<△Tsh_min, if Tr<Tr_min, the fan speed V is controlled to increase by 3 rpm / s; if Tr_min≤Tr≤Tr_max, the fan speed V is controlled to increase by 1 rpm / s; if Tr>Tr_max, the fan speed V is controlled to increase by 1 rpm / 2s. When △Tsh>△Tsh_max, if Tr<Tr_min, the fan speed V is controlled to decrease by 1rpm / 2s; if Tr_min≤Tr≤Tr_max, the fan speed V is controlled to decrease by 1rpm / s; if Tr>Tr_max, the fan speed V is controlled to decrease by 3rpm / s. Wherein, Tr_min is the low threshold of ambient temperature, and Tr_max is the high threshold of ambient temperature. The low threshold Tr_min is 8℃, and the high threshold Tr_max is 35℃.

10. The fan speed control method according to any one of claims 7 or 9, characterized in that, Step S10 further includes: based on the compressor's target operating frequency F target The initial speed V0 of the fan is calculated, specifically expressed by the following formula: V0=K×F target ×10 Wherein, K is the determination coefficient for the initial speed of the fan, which is determined as follows: obtain the current ambient temperature Tr, determine the magnitude of the ambient temperature Tr, and determine the value of the determination coefficient K for the initial speed of the fan based on the determination result: When Tr < Tr_min, the initial speed determination coefficient K of the fan is 1.

2. When Tr_min≤Tr≤Tr_max, the initial speed determination coefficient K of the fan is 1. When Tr > Tr_max, the initial speed determination coefficient K of the fan is 0.8.

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