Cooling fan rotating speed control method and device suitable for unstable heat source

Abstract

The invention discloses a cooling fan rotating speed control method and device suitable for an unstable heat source, and the control method comprises the steps: obtaining an indoor environment temperature and a heat source temperature, and setting a target temperature; according to the heat source temperature and the environment temperature, a first difference value is obtained, and according to the first difference value, the theoretical rotating speed of operation of a cooling fan is generated; a second difference value is obtained according to the target temperature and the environment temperature, and the influence rotating speed of operation of the cooling fan is generated according to the second difference value; and according to the theoretical rotation speed and the influence rotation speed, obtaining the actual rotation speed of the cooling fan. The rotating speed of the cooling fan is corrected by adding the environment temperature, so that the stability of the environment temperature is improved, the operation noise of the cooling fan is reduced, and the comfort of a human body is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature regulation, and in particular to a speed control method and a control device for a heat dissipation fan applicable to an unstable heat source. Background Art

[0002] In old residential areas in northern my country, cast iron radiators are usually used for heating, which mainly rely on heat radiation and passive convection to dissipate heat. However, most families install radiator covers for aesthetic purposes, which not only seriously affects the heat dissipation of heat radiation, but also leads to poor convection heat dissipation. It also causes the temperature inside the radiator cover to be very high, while the temperature outside the radiator cover is very low.

[0003] Existing auxiliary heat dissipation technologies mostly involve adding fans to enhance convection-assisted heat dissipation. The speed of the cooling fan is usually uncontrolled or only relies on linear control based on the radiator temperature. That is, the higher the radiator temperature, the faster the cooling fan speed. This will result in problems such as loud noise and excessively high maximum ambient temperature.

[0004] Air energy and solar energy heating and cooling devices generally use fan coil radiators, and some also use radiators. The temperature control system is similar to that of central air conditioning. It only relies on the built-in temperature sensor of the hand operator to monitor the ambient temperature to control the speed of the cooling fan. This means that when the water temperature is low, it is still possible to trigger a large air volume, resulting in too low an air outlet temperature, causing the human body to feel poor. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a cooling fan speed control method and control device applicable to unstable heat sources. The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0006] A method for controlling the speed of a cooling fan applicable to an unstable heat source, comprising:

[0007] Step 1: Get the indoor ambient temperature, heat source temperature, and set the target temperature;

[0008] Step 2: obtaining a first difference value according to the heat source temperature and the ambient temperature, and generating a theoretical speed of the cooling fan according to the first difference value;

[0009] Step 3: obtaining a second difference value according to the target temperature and the ambient temperature, and generating an influencing speed of the cooling fan operation according to the second difference value;

[0010] Step 4: Obtain the actual speed of the cooling fan according to the theoretical speed and the influencing speed.

[0011] Furthermore, the step 2 comprises:

[0012] Step 2.1: Subtract the heat source temperature from the ambient temperature to obtain a first difference value;

[0013] Step 2.2: Setting the upper limit and lower limit of the first difference;

[0014] Step 2.3: Calculate the theoretical speed of the cooling fan according to the upper limit value, the lower limit value of the first difference and the first difference.

[0015] Furthermore, the calculation formula for the theoretical speed of the cooling fan in step 2.3 is:

[0016]

[0017] In the formula, is the theoretical speed of the cooling fan; is the upper limit of the first difference; is the lower limit of the first difference; is the first difference.

[0018] Furthermore, the step 3 comprises:

[0019] Step 3.1: Subtract the target temperature from the ambient temperature to obtain a second difference value;

[0020] Step 3.2: Setting the upper limit and lower limit of the second difference;

[0021] Step 3.3: Calculate the influencing speed of the cooling fan according to the upper limit value, the lower limit value and the second difference.

[0022] Furthermore, the calculation formula for the speed affecting the operation of the cooling fan in step 3.2 is:

[0023]

[0024] In the formula, is the theoretical speed of the cooling fan; is the upper limit of the second difference; is the lower limit of the second difference; is the second difference.

[0025] Furthermore, in step 4, the theoretical rotational speed is multiplied by the influencing rotational speed to obtain the actual rotational speed of the cooling fan.

[0026] Another embodiment of the present invention further discloses a control device for the speed control method of a heat dissipation fan for an unstable heat source described in any of the above embodiments, comprising:

[0027] A temperature acquisition unit, used to acquire indoor environment temperature and heat source temperature;

[0028] A data processing unit is used to receive the indoor environment temperature, the heat source temperature and the target temperature, and process them to obtain the actual speed of the cooling fan;

[0029] The fan control unit is used to receive the actual speed of the cooling fan and control the rotation of the cooling fan.

[0030] Beneficial effects of the present invention:

[0031] 1. The present invention solves the problem that the target temperature does not meet expectations due to inappropriate cooling fan speed during heating with unstable heat source. The fan speed is corrected by adding the ambient temperature, thereby improving the stability of the ambient temperature and the human body comfort.

[0032] 2. This method solves the problem that the cooling fan coil unit that depends on the ambient temperature for speed regulation cannot monitor the heat source temperature, and the cooling fan may run in a high speed range when the heat source temperature is low.

[0033] 3. This method solves the problem of traditional radiator auxiliary cooling fans that rely on heat source temperature to adjust speed. When the radiator temperature is high, the fan speed is high, causing the ambient temperature to exceed the human comfort temperature and heat waste.

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 For R 1 Follow Trend chart of changes;

[0036] Figure 2 For R 2 Follow Trend chart of changes;

[0037] Figure 3 is a control block diagram of the present invention;

[0038] Figure 4 It is the control principle diagram of the present invention.

[0039] Description of reference numerals:

[0040] 1- Temperature acquisition unit; 2- Data processing unit; 3- Fan control unit. DETAILED DESCRIPTION

[0041] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0042] See also Figure 1~Figure 2 The embodiment of the present invention discloses a cooling fan speed control method applicable to unstable heat sources, which specifically includes the following methods:

[0043] Step 1: Get the indoor ambient temperature, heat source temperature, and set the target temperature;

[0044] Step 2: obtaining a first difference value according to the heat source temperature and the ambient temperature, and generating a theoretical speed of the cooling fan according to the first difference value;

[0045] Step 3: obtaining a second difference value according to the target temperature and the ambient temperature, and generating an influencing speed of the cooling fan operation according to the second difference value;

[0046] Step 4: Obtain the actual speed of the cooling fan according to the theoretical speed and the influencing speed.

[0047] Furthermore, the step 2 comprises the following steps:

[0048] Step 2.1: Subtract the heat source temperature from the ambient temperature to obtain a first difference value;

[0049] Step 2.2: Setting the upper limit and lower limit of the first difference;

[0050] Step 2.3: Calculate the theoretical speed of the cooling fan according to the upper limit value, the lower limit value of the first difference and the first difference.

[0051] Specifically, the calculation formula for the theoretical speed of the cooling fan is:

[0052]

[0053] In the formula, is the theoretical speed of the cooling fan; is the upper limit of the first difference; is the lower limit of the first difference; is the first difference.

[0054] Figure 1 For R 1 Follow Trend chart of changes; when When the value is greater than the upper limit of the first difference, the cooling fan keeps running at full speed; When the value is less than the lower limit of the first difference, the cooling fan stops running.

[0055] Furthermore, the step 3 comprises the following steps:

[0056] Step 3.1: Subtract the target temperature from the ambient temperature to obtain a second difference value;

[0057] Step 3.2: Setting the upper limit and lower limit of the second difference;

[0058] Step 3.3: Calculate the influencing speed of the cooling fan according to the upper limit value, the lower limit value and the second difference.

[0059] Specifically, the calculation formula affecting the speed of the cooling fan is:

[0060]

[0061] In the formula, is the theoretical speed of the cooling fan; is the upper limit of the second difference; is the lower limit of the second difference; is the second difference.

[0062] Figure 2 For R 2 Follow Trend chart of changes; when When it is greater than the upper limit of the second difference, the cooling fan keeps running at full speed; When it is less than the lower limit of the second difference, the cooling fan stops running.

[0063] Furthermore, in step 4, the theoretical speed of the cooling fan obtained in step 2 is multiplied by the speed of the cooling fan obtained in step 3 to obtain the actual speed of the cooling fan, that is,

[0064]

[0065] Where R is the actual speed of the cooling fan.

[0066] In a specific embodiment of the present invention, it is assumed that the current ambient temperature is 22°C, the heat source temperature is 40°C, and the target temperature is 25°C; the lower limit of the first difference is set to 3°C, and the upper limit of the first difference is set to 30°C; the lower limit of the second difference is set to 0°C, and the upper limit of the second difference is set to 10°C; according to the calculation formula of the theoretical speed, the influencing speed and the actual speed of the cooling fan, it can be known that:

[0067] Theoretical speed of cooling fan , then R1=55.6%;

[0068] The influence of cooling fan running speed , then R2=30%;

[0069] The actual speed of the cooling fan .

[0070] It can be concluded that when the heat source temperature is high and the temperature difference between the ambient temperature and the target temperature is small, the cooling fan operates in a lower speed range to maintain the ambient temperature near the target temperature.

[0071] In another specific embodiment of the present invention, it is assumed that the current ambient temperature is 5°C, the heat source temperature is 50°C, and the target temperature is 20°C; the lower limit of the first difference is set to 4°C, and the upper limit of the first difference is set to 33°C; the lower limit of the second difference is set to 2°C, and the upper limit of the second difference is set to 20°C; according to the calculation formula of the theoretical speed, the speed affecting the speed, and the actual speed of the cooling fan, it can be known that:

[0072] Theoretical speed of cooling fan , R1=100%;

[0073] The influence of cooling fan running speed R2=72.2%;

[0074] The actual speed of the cooling fan is R= .

[0075] It can be concluded that when the heat source temperature is high and the ambient temperature has a large temperature difference from the target temperature, the cooling fan operates in a higher speed range to quickly increase the ambient temperature.

[0076] In another specific embodiment of the present invention, assuming that the current ambient temperature is 4°C, the heat source temperature is 20°C, and the target temperature is 18°C; the lower limit of the first difference is set to 2°C, and the upper limit of the first difference is set to 28°C; the lower limit of the second difference is set to 1°C, and the upper limit of the second difference is set to 21°C; according to the calculation formula of the theoretical speed, the speed affecting the speed, and the actual speed of the cooling fan, it can be known that:

[0077] Theoretical speed of cooling fan , 53.8%;

[0078] The influence of cooling fan running speed ,but 65%;

[0079] The actual speed of the cooling fan is R= .

[0080] It can be concluded that when the heat source temperature is low and the ambient temperature has a large temperature difference from the target temperature, the cooling fan runs at a lower speed to prevent low-temperature wind from causing discomfort to the human body.

[0081] In another specific embodiment of the present invention, it is assumed that the current ambient temperature is 25°C, the heat source temperature is 30°C, and the target temperature is 23°C; the lower limit of the first difference is set to 3°C, and the upper limit of the first difference is set to 30°C; the lower limit of the second difference is set to 1°C, and the upper limit of the second difference is set to 15°C; according to the calculation formula of the theoretical speed, the speed affecting the speed, and the actual speed of the cooling fan, it can be known that:

[0082] Theoretical speed of cooling fan , 7%;

[0083] The influence of cooling fan running speed ),but 0;

[0084] The actual speed of the cooling fan is R= .

[0085] It can be concluded that when the ambient temperature exceeds the target temperature, the cooling fan stops running to prevent the ambient temperature from being too high.

[0086] In another specific embodiment of the present invention, it is assumed that the current ambient temperature is 29°C, the heat source temperature is 28°C, and the target temperature is 25°C; the lower limit of the first difference is set to 2°C, and the upper limit of the first difference is set to 29°C; the lower limit of the second difference is 0°C, and the upper limit of the second difference is 12°C; according to the calculation formula of the theoretical speed, the speed affecting the speed, and the actual speed of the cooling fan, it can be known that:

[0087] Theoretical speed of cooling fan , 0;

[0088] The influence of cooling fan running speed ),but 0;

[0089] The actual speed of the cooling fan is R= .

[0090] It can be concluded that when the temperature difference between the heat source temperature and the ambient temperature is less than the set value, the cooling fan stops running to prevent the heat source from absorbing heat from the environment.

[0091] Example 2

[0092] See also Figure 3~4 The embodiment of the present invention provides a cooling fan speed control device suitable for unstable heat sources, comprising:

[0093] The temperature acquisition unit is used to acquire the indoor ambient temperature and the heat source temperature; the temperature acquisition unit includes a first temperature sensor for monitoring the ambient temperature and a second temperature sensor for monitoring the heat source temperature; the first temperature sensor and the second temperature sensor are both thermocouple sensors and are not affected by the wiring length.

[0094] A data processing unit is used to receive the indoor environment temperature, the heat source temperature and the target temperature set by the user, and perform calculations to obtain the actual speed of the cooling fan;

[0095] The fan control unit is used to receive the actual speed of the heat dissipation fan and control the fan speed regulator of the heat dissipation fan so that the heat dissipation fan rotates at a corresponding speed.

[0096] The data processing unit and the fan control unit are integrated in the core controller, which has the required temperature control function built in. The current required motor speed is calculated by bringing the ambient temperature, the heat source temperature and the set target temperature into the corresponding function, and the motor speed is controlled through the corresponding output terminal.

[0097] Furthermore, the fan speed regulator can be a common AC motor speed regulator or AC motor frequency converter using a knob for speed regulation, or a DC motor speed regulator based on PWM, such as Figure 4 As shown, the core controller outputs different control signals through the different corresponding control objects.

[0098] When the control object is a PWM speed-regulated fan, the core controller outputs a PWM waveform signal to control the speed of the DC motor based on PWM speed regulation, thereby controlling the speed of the fan;

[0099] When the control object is an AC fan that uses a frequency converter to adjust the speed, the core controller can output 4~20mA, 0~5V, 0~10V analog signals to control the frequency converter of the AC fan, thereby controlling the speed of the AC fan;

[0100] When the control object is an AC fan that uses a knob to adjust the speed, a stepper motor can be installed on the knob, and the core controller outputs a stepper motor control signal to control the rotation angle of the stepper motor shaft. The stepper motor controls the knob of the AC fan speed regulator to control the speed of the AC motor.

[0101] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A cooling fan speed control method suitable for unstable heat sources, characterized in that: include: Step 1: Get the indoor ambient temperature, heat source temperature, and set the target temperature; Step 2: obtaining a first difference value according to the heat source temperature and the ambient temperature, and generating a theoretical speed of the cooling fan according to the first difference value; Step 3: obtaining a second difference value according to the target temperature and the ambient temperature, and generating an influencing speed of the cooling fan operation according to the second difference value; Step 4: Obtain the actual speed of the cooling fan according to the theoretical speed and the influencing speed.

2. The cooling fan speed control method applicable to unstable heat sources according to claim 1, characterized in that: The step 2 comprises: Step 2.1: Subtract the heat source temperature from the ambient temperature to obtain a first difference value; Step 2.2: Setting the upper limit and lower limit of the first difference; Step 2.3: Calculate the theoretical speed of the cooling fan according to the upper limit value, the lower limit value of the first difference and the first difference.

3. The cooling fan speed control method applicable to unstable heat sources according to claim 2, characterized in that: The calculation formula for the theoretical speed of the cooling fan in step 2.3 is: In the formula, is the theoretical speed of the cooling fan; is the upper limit of the first difference; is the lower limit of the first difference; is the first difference.

4. The cooling fan speed control method applicable to unstable heat sources according to claim 1, characterized in that: The step 3 comprises: Step 3.1: Subtract the target temperature from the ambient temperature to obtain a second difference value; Step 3.2: Setting the upper limit and lower limit of the second difference; Step 3.3: Calculate the influencing speed of the cooling fan according to the upper limit value, the lower limit value and the second difference.

5. The cooling fan speed control method applicable to unstable heat sources according to claim 4, characterized in that: The calculation formula for the speed affecting the operation of the cooling fan in step 3.2 is: In the formula, is the theoretical speed of the cooling fan; is the upper limit of the second difference; is the lower limit of the second difference; is the second difference.

6. The cooling fan speed control method applicable to unstable heat sources according to claim 1, characterized in that: In step 4, the actual speed of the cooling fan is obtained by multiplying the theoretical speed by the influencing speed.

7. A control device for the speed control method of a heat dissipation fan for an unstable heat source according to any one of claims 1 to 6, characterized in that: include: A temperature acquisition unit, used to acquire indoor environment temperature and heat source temperature; A data processing unit is used to receive the indoor environment temperature, the heat source temperature and the target temperature, and process them to obtain the actual speed of the cooling fan; The fan control unit is used to receive the actual speed of the cooling fan and control the rotation of the cooling fan.

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