Temperature control method of heating and ventilation system and heating and ventilation system controller

Abstract

The invention provides a temperature control method of a heating and ventilation system. The temperature control method comprises the following steps that the current temperature of the heating and ventilation system is collected; the heating rate and the cooling rate of the heating and ventilation system are calculated; respectively calculating the heating duration and the cooling duration required by the heating and ventilation system; entering the control stage while exiting the prediction stage; and after entering the control stage, according to the heating duration and the cooling duration, the continuous heating time and the continuous cooling time of the heating and ventilation system are controlled, so that the current temperature is kept within the amplitude error interval of the set temperature. The invention further provides a heating and ventilation system controller. According to the heating rate, the cooling rate, the heating duration obtained through calculation and the cooling duration obtained through calculation, the continuous heating time and the continuous cooling time of the heating and ventilation system are controlled, the acceptable temperature difference is allowed to exist, the current temperature is dynamically stable within the amplitude error of the allowed set temperature, the temperature adjusting frequency can be reduced, and power consumption can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature control of a HVAC system, and in particular to a temperature control method of a HVAC system and a HVAC system controller. Background Art

[0002] The HVAC system mainly includes two types: HVAC and HVACR. HVAC (Heating, Ventilation, Air-conditioning and Cooling) is a system or related equipment responsible for heating, ventilation and air conditioning in a room or car. It consists of three main parts: heat medium preparation (heat source), heat medium transportation and heat medium utilization (heat dissipation equipment). It can control the temperature and humidity of the air and improve the comfort level in the room or car. Some HVAC systems will also add a cooler, namely HVACR (Heating, Ventilation and Air Conditioning, Refrigeration). In addition to HVAC, it also includes a refrigerant circuit for passing fluids, and removes heat from the process fluid through a refrigeration cycle (for example, a vapor compression cycle).

[0003] The thermostat of the HVAC system is used to control the temperature of a single-stage or multi-stage traditional HVAC system or heat pump system. It generally adopts a specific algorithm to control the air outlet to blow cold or hot air by turning on / off the refrigerator or heater, so that the indoor temperature is stably maintained near the set temperature.

[0004] Common algorithms generally include threshold comparison method and PID algorithm. Among them, the threshold comparison method compares the current temperature with the preset temperature to determine whether the heater / cooler needs to be turned on or off, but there is a problem of large control error. Take the HVAC system controlling the heater as an example. When the heater is turned on to increase the indoor temperature, it still takes some time for the indoor temperature to be transmitted to the temperature sensor inside the HVAC system, that is, when the temperature sensor detects that the set temperature has been reached, the indoor temperature is already greater than the set temperature, which will cause a certain error; when the heater is turned off, due to temperature inertia, the indoor temperature will rise for a period of time before it starts to drop, so there will be a certain error. Similarly, when the cooler is used for cooling control, a certain error will also be generated. In addition, due to the difference in the room's thermal insulation and the heat transfer of the HVAC system itself, the thermal inertia will be more obvious, resulting in a large control error.

[0005] The PID algorithm uses the PWM algorithm to adjust the fixed heating speed / cooling speed to a variable speed. When the indoor temperature is near the set temperature, high-frequency PWM is required to stabilize the temperature change rate at a smaller value to reduce the impact error caused by the higher speed. However, the PID algorithm is easily affected by the ambient temperature, which makes the parameter setting process very difficult. In addition, the purpose of the PID algorithm is to eliminate control errors. Frequent on-off control may be required, which will have an adverse effect on the service life of the HVAC system. Summary of the invention

[0006] The purpose of the present invention is to provide a temperature control method for a HVAC system and a HVAC system controller designed to solve the deficiencies of the above-mentioned technology.

[0007] The present invention designs a temperature control method for a HVAC system, comprising the following steps:

[0008] Collect the current temperature of the temperature control environment of the HVAC system according to the temperature measurement cycle;

[0009] Enter the prediction stage to calculate the cooling rate and heating rate of the HVAC system;

[0010] The cooling rate is calculated as follows:

[0011] Calculate the temperature change rate when the temperature drops from the previous moment to the current temperature being less than or equal to the minimum allowable temperature in a temperature measurement cycle as the cooling rate;

[0012] The heating rate is calculated as follows:

[0013] Calculate the temperature change rate when the temperature rises from the previous moment to the current temperature being greater than or equal to the maximum allowable temperature in a temperature measurement cycle as the heating rate;

[0014] According to the heating rate, the cooling rate and the amplitude error, respectively calculating the heating time and cooling time required for the HVAC system;

[0015] Exit the prediction phase and enter the control phase;

[0016] After entering the control stage, the continuous heating time and continuous cooling time of the HVAC system are controlled according to the heating time and cooling time, so as to realize the heating and cooling of the HVAC system respectively, so that the current temperature is kept within the amplitude error of the set temperature.

[0017] Furthermore, the heating time is calculated as follows:

[0018]

[0019] The cooling time is calculated as follows:

[0020]

[0021] Among them, OnTime_balance is the heating time, OffTime_balance is the cooling time, V_up is the heating rate, V_down is the cooling rate, and Error_target is the amplitude error interval width, which is twice the amplitude error.

[0022] Furthermore, the step of entering the prediction phase and calculating the cooling rate and heating rate of the HVAC system includes the following steps:

[0023] Determine whether the current temperature is greater than or equal to the maximum allowable temperature. If so, control the HVAC system to cool down.

[0024] After the HVAC system is controlled to cool down, it is determined whether the current temperature is less than or equal to the minimum allowable temperature. If the current temperature is less than or equal to the minimum allowable temperature, the HVAC system is controlled to heat up, and the cooling rate is calculated;

[0025] After controlling the HVAC system to heat up, it is determined whether the current temperature is greater than or equal to the maximum allowable temperature for the second time. If it is greater than or equal to the maximum allowable temperature, the HVAC system is controlled to cool down, and the heating rate is calculated.

[0026] Furthermore, the step of entering the prediction phase and calculating the cooling rate and heating rate of the HVAC system includes the following steps:

[0027] Determine whether the current temperature is less than or equal to the minimum allowable temperature. If so, control the HVAC system to increase the temperature.

[0028] After the HVAC system is controlled to heat up, it is determined whether the current temperature is greater than or equal to the maximum allowable temperature. If the current temperature is greater than or equal to the maximum allowable temperature, the HVAC system is controlled to cool down, and the heating rate is calculated;

[0029] After controlling the HVAC system to cool down, it is determined whether the current temperature is less than or equal to the minimum allowable temperature for the second time. If it is less than or equal to the minimum allowable temperature, the HVAC system is controlled to heat up, and the cooling rate is calculated.

[0030] Further, the step of exiting the prediction phase and entering the control phase comprises the following steps: when the current temperature collected satisfies the first control condition, exiting the prediction phase and entering the control phase;

[0031] The first control condition is that, during the cooling process after calculating the heating rate, when the current temperature is equal to the set temperature or is lower than the set temperature for the first time;

[0032] Alternatively, when the current temperature collected satisfies the second control condition, the prediction phase is exited and the control phase is entered;

[0033] The second control condition is that, during the cooling process after the heating rate is calculated, when the current temperature is equal to or less than the sum of the set temperature and the amplitude error for the first time;

[0034] Alternatively, when the current temperature collected satisfies the third control condition, the prediction phase is exited and the control phase is entered;

[0035] The third control condition is that, during the cooling process after the heating rate is calculated, when the current temperature is equal to or less than the difference between the set temperature and the amplitude error for the first time.

[0036] Further, the exiting the prediction phase and entering the control phase at the same time comprises the following steps: when the current temperature collected satisfies the fourth temperature control condition, the exiting the prediction phase and entering the control phase at the same time;

[0037] The fourth temperature control condition is that during the heating process after the cooling rate is calculated, when the current temperature is equal to the set temperature or is greater than the set temperature for the first time;

[0038] Alternatively, when the current temperature collected satisfies the fifth temperature control condition, the prediction phase is exited and the control phase is entered;

[0039] The fifth temperature control condition is that, during the heating process after the cooling rate is calculated, when the current temperature is equal to or greater than the sum of the set temperature and the amplitude error for the first time;

[0040] Alternatively, when the current temperature collected satisfies the sixth temperature control condition, the prediction phase is exited and the control phase is entered;

[0041] The sixth temperature control condition is that, during the heating process after the cooling rate is calculated, when the current temperature is equal to or greater than the difference between the set temperature and the amplitude error for the first time.

[0042] Furthermore, after entering the control phase;

[0043] Control the HVAC system to cool down, and the continuous cooling time is the product of the cooling time and the first coefficient; then control the HVAC system to heat up and cool down alternately, and the continuous heating time is the product of the heating time and the second coefficient, and the continuous cooling time is the product of the cooling time and the third coefficient;

[0044] Alternatively, the HVAC system is controlled to heat up, and the continuous heating time is the product of the heating time and the first coefficient; then the HVAC system is controlled to cool down and heat up alternately, and the continuous cooling time is the product of the cooling time and the second coefficient, and the continuous heating time is the product of the heating time and the third coefficient.

[0045] Furthermore, the HVAC system includes a heater, which is started when the temperature rises, and the heating time is the heater start time; the heater is turned off when the temperature drops, and the temperature drop time is the heater shut-down time;

[0046] Alternatively, the HVAC system includes a heater and a cooler. When the temperature rises, the heater is started and the cooler is in an off state, and the heating time is equal to the start-up time of the heater. When the temperature drops, the heater is turned off for natural cooling, and the cooler is started for active cooling. The cooling time is equal to the off time of the heater and the start-up time of the cooler.

[0047] Furthermore, the method further comprises the following steps:

[0048] The prediction phase begins only after the prediction conditions are met;

[0049] The prediction condition is a first prediction condition, and the first prediction condition is that the HVAC system controller is running for the first time;

[0050] Alternatively, the prediction condition is a second prediction condition, and the second prediction condition includes one of the following conditions:

[0051] In the control stage, when the peak value of the current temperature continuously collected is greater than the maximum allowable temperature for a first set number of times;

[0052] In the control stage, when the valley value of the current temperature continuously collected is less than the minimum allowable temperature for a second set number of times;

[0053] In the control stage, the current error is obtained, and when the current error is greater than the product of the amplitude error and the threshold coefficient.

[0054] The present invention also provides a HVAC system controller, which adopts the temperature control method of the HVAC system.

[0055] The temperature control method and HVAC system controller provided by the present invention have the technical effect of calculating the heating time and the cooling time according to the heating rate and the cooling rate, respectively, and controlling the continuous heating time and the continuous cooling time of the HVAC system, allowing an acceptable temperature difference to exist, and making the current temperature dynamically stable within the allowable amplitude error of the set temperature, which can reduce the number of temperature adjustments and reduce power consumption, while making the temperature control accuracy controllable and the temperature control consistency good. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is a temperature change waveform diagram of Example 1 in a temperature control method for a HVAC system provided by the present invention;

[0057] Figure 2 It is a temperature change waveform diagram of Example 2 in a temperature control method for a HVAC system provided by the present invention;

[0058] Figure 3 It is a temperature change waveform diagram of Example 3 in a temperature control method for a HVAC system provided by the present invention;

[0059] Figure 4 It is a temperature change waveform diagram of Example 4 in a temperature control method for a HVAC system provided by the present invention;

[0060] Figure 5 It is a temperature change waveform diagram of Example 6 in a temperature control method for a HVAC system provided by the present invention;

[0061] Figure 6 yes Figure 1 Schematic diagram of the steps;

[0062] Figure 7 yes Figure 1 Schematic diagram of the process;

[0063] Figure 8 yes Figure 7 Flowchart of the forecasting phase;

[0064] Fig. 9 yes Figure 7 Flowchart of the middle control phase;

[0065] Fig.10 It is a temperature change waveform diagram of Example 9 in a temperature control method for a HVAC system provided by the present invention;

[0066] Fig.11 yes Fig.10 Flowchart of the prediction phase. DETAILED DESCRIPTION

[0067] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0068] Example 1

[0069] In this embodiment, Figure 6As shown, the present invention discloses a temperature control method for a HVAC system, which is used to control the temperature of the HVAC system. The HVAC system and the HVAC system controller constitute a temperature control system. In this embodiment, the application scenario of the temperature control system is housing, and the temperature acquisition or ambient temperature is the room temperature of the room. Among them, the temperature control method includes the following S1-S6, a total of 6 steps. The 6 steps can be continuous steps, or there can be other steps that are known or mastered by those skilled in the art between the steps; even, the order of some of the 6 steps can be reversed, such as the relevant steps in the prediction stage and the relevant steps in the control stage.

[0070] S1: Collect the current temperature Temp_current of the temperature control environment of the HVAC system according to the temperature measurement cycle Time_unit.

[0071] The value of the temperature measurement period Time_unit is determined before leaving the factory based on the user's application scenario, which includes the size of the room, the heat dissipation performance of the HVAC system, and the output power of the control object (i.e., the HVAC system, such as heaters, coolers, etc.). The current temperature Temp_current will detect and obtain the latest temperature value of the temperature control environment every temperature measurement period Time_unit.

[0072] In this embodiment, the temperature measurement period Time_unit is 10s. In the absence of interference (for example, the impact of the external ambient temperature and the aging of the HVAC system on the temperature change is not considered), the temperature 10s before or 10s after the current temperature is relatively small compared to the current temperature Temp_current, generally around 0.5°C, and will not exceed 1°C. Therefore, it can meet the needs of subsequent parameter prediction and control.

[0073] S2: When entering the prediction stage, if the current temperature Temp_current is greater than the maximum allowable temperature, the HVAC system is controlled to cool down, otherwise the HVAC system is controlled to heat up.

[0074] Generally, when the ambient temperature is lower than the set temperature Temp_target (e.g. in winter), a heater is needed to raise the room temperature in the room. Therefore, the HVAC system includes a heater. Figure 7 As shown, the prediction stage is entered only after the prediction condition is met; the prediction condition can be the first prediction condition. The first prediction condition is that the HVAC system controller is running for the first time. When the HVAC system controller is running for the first time, it enters the prediction stage by default, first judging the temperature range of the current temperature Temp_current. When the collected current temperature Temp_current is greater than the maximum allowable temperature, the heater is controlled or kept turned off for cooling; otherwise, the heater is controlled or kept turned on for heating.

[0075] In some embodiments, the heater may be an air conditioner with a heating function. In addition, the heater of the HVAC system may also be a water heating system, which includes a boiler for supplying hot water and a water pipe connected to the boiler and arranged in the room; the water heating system is controlled to achieve a rise in the room temperature. Obviously, the heater may also be other devices with heating or heating functions.

[0076] Among them, the maximum allowable temperature is the sum of the set temperature Temp_target and the balance area temperature Temp_balanceLine, that is, Temp_target+Temp_balanceLine. Figure 1 In the shown embodiment, the set temperature Temp_target is 20°C; obviously, the set temperature Temp_target can be set according to user needs. The balance area temperature Temp_balanceLine is 2°C, that is, the maximum allowable temperature is equal to 22°C. The minimum allowable temperature is the difference between the set temperature Temp_target and the balance area temperature Temp_balanceLine, that is, Temp_target-Temp_balanceLine. Obviously, the minimum allowable temperature in this embodiment is equal to 18°C. The balance area temperature Temp_balanceLine is set before leaving the factory and generally cannot be modified by the user. In this embodiment, the HVAC system does not include a cooler. Cooling the HVAC system means turning off the heater, thereby cooling naturally. This situation is applied to the use scenario where the HVAC system is HVAC.

[0077] S3: In the prediction stage, the heating rate V_up and cooling rate v_down of the HVAC system are calculated.

[0078] like Figure 8 As shown, step S3 specifically includes the following 9 steps S31-S39:

[0079] S31: Determine whether the collected current temperature Temp_current is greater than or equal to the maximum allowable temperature, and then proceed to step S32 or S33.

[0080] S32: If the temperature is greater than or equal to the maximum allowable temperature, control the HVAC system to cool down, that is, control or keep the heater off. Figure 1 As shown, the temperature will continue to rise to the maximum temperature due to thermal inertia and then decrease, that is, the subsequent cooling process will start from above the maximum allowable temperature.

[0081] S33: If it is less than the maximum allowable temperature, the HVAC system is controlled to increase the temperature, that is, the heater is controlled or kept started, until the collected current temperature Temp_current is greater than or equal to the maximum allowable temperature, and then the HVAC system is controlled to cool down. Among them, the current temperature Temp_current is collected and updated every temperature measurement period Temp_unit, and the updated current temperature Temp_current is compared with the maximum allowable temperature.

[0082] S34: After the HVAC system is controlled to cool down, it is determined whether the collected current temperature Temp_current is equal to or less than the minimum allowable temperature for the first time, and then the process goes to step S35 or S36.

[0083] S35: If it is equal to or lower than the minimum allowable temperature for the first time, control the HVAC system to heat up, i.e. start the heater, and calculate the temperature change rate v_current at the current moment as the actual cooling rate V_down. Figure 1 As shown, the temperature will continue to drop from the minimum allowable temperature to the minimum temperature due to thermal inertia and then start to rise.

[0084] S36: If it is greater than the minimum allowable temperature, the HVAC system is kept cooling down until the collected current temperature Temp_current is equal to or less than the minimum allowable temperature for the first time, then the HVAC system is controlled to heat up, i.e. the heater is started, and the cooling rate V_down is calculated. Among them, the current temperature Temp+current is collected and updated every temperature measurement period Time_unit, and the updated current temperature Temp_current is compared with the minimum allowable temperature.

[0085] The temperature drop rate V_down is calculated, that is, the temperature change rate when the temperature drops from the previous moment to the current temperature is less than or equal to the minimum allowable temperature for the first time after a temperature measurement cycle.

[0086] Use the following formula:

[0087]

[0088] Among them, V_current is the temperature change rate at any current moment, Temp_current is the current temperature, Temp_previous is the temperature at the previous moment, and the interval between the previous moment and the current moment is equal to a temperature measurement cycle Time_unit. Obviously, when calculating the cooling rate V_down, if the current temperature happens to be equal to the minimum allowable temperature, then

[0089] S37: After the HVAC system is controlled to heat up, it is determined whether the collected current temperature Temp_current is greater than or equal to the maximum allowable temperature for the second time, and then the process goes to step S38 or S39.

[0090] S38: If the temperature is greater than or equal to the maximum allowable temperature for the second time, the HVAC system is controlled to cool down, that is, the heater is turned off for cooling down and the temperature change rate V_current at the current moment is calculated as the actual heating rate V_up, and the run flag Runflag is recorded as 1.

[0091] S39: If the temperature is lower than the maximum allowable temperature, the HVAC system is kept heating up until the collected current temperature Temp_current is greater than or equal to the maximum allowable temperature for the second time, and the HVAC system is controlled to cool down, that is, the heater is turned off, and the heating rate V_up is calculated. The current temperature Temp_current is collected and updated every temperature measurement period Time_unit, and the updated current temperature Temp_current is compared with the maximum allowable temperature.

[0092] The temperature rise rate V_up is calculated, that is, the temperature change rate when the temperature rises from the previous moment to the current temperature being greater than or equal to the maximum allowable temperature for the second time after a temperature measurement cycle.

[0093] Use the following formula:

[0094]

[0095] Among them, Temp_current is the current temperature, Temp_previous is the temperature at the previous moment, and the interval between the previous moment and the current moment is equal to a temperature measurement cycle Time_unit. Obviously, when calculating the heating rate V_up, if the current temperature is equal to the maximum allowable temperature for the second time, then

[0096] In the prediction stage, since the time of calculating the cooling rate V_down is the time of controlling the heating system to heat up, it can be the time when the current temperature is equal to the minimum allowable temperature during the cooling process, or it can be the time when the current temperature is less than the minimum allowable temperature for the first time during the cooling process. Figure 1As shown, when entering the prediction stage, the heater in this embodiment is in the start-up and heating state, and the current temperature Temp_current is collected and updated every temperature measurement period Time_unit; when it is detected that the current temperature Temp_curent is still less than 22°C (for example, Temp_current=21°C), the heater is kept started and the heating is continued until it is detected that the current temperature Temp_current is equal to 22°C or is greater than 22°C for the first time (for example, the current temperature Temp_current=22.4°C), the heater is turned off for the first time, and thereafter the current temperature will continue to rise to the maximum temperature due to thermal inertia before starting to gradually decrease.

[0097] When it is detected that the current temperature Temp_current drops to 18°C ​​or is less than 18°C ​​for the first time, the cooling rate V_down is calculated. In one embodiment, it is detected that the current temperature Temp_current drops to 17.8°C and is less than 18°C ​​for the first time; the cooling rate V_down is calculated at this time, the current temperature at this moment is 17.8°C, and the previous moment temperature Temp_previous is the temperature corresponding to the previous moment when the current temperature is 17.8°C, and the heater is started for the second time while calculating the cooling rate V_down.

[0098] Since the starting conditions of the first heating process are unknown during the entire process of the prediction stage, it is uncertain whether the prediction stage is entered due to interference in the control stage (such as the case of Example 4-7) or the HVAC system controller enters the prediction stage for the first time; furthermore, the first heating process in the prediction stage may be affected by uncertain factors not involving the HVAC system. In order to reduce the prediction error, the first heating process in the prediction stage is not used to calculate the heating rate V_up. Then, starting from cooling, the cooling rate V_down is calculated first and then the heating rate V_up is calculated.

[0099] Similarly, in the prediction stage, due to the moment of calculating the heating rate V_up, that is, the moment when the HVAC system is controlled to turn off the heater to cool down, the collected current temperature Temp_current is not necessarily equal to the maximum allowable temperature, but the moment when it is greater than the maximum allowable temperature for the second time in the prediction stage. Since the HVAC system has been started, there has been a moment greater than or equal to the maximum allowable temperature; the second moment greater than or equal to the maximum allowable temperature here refers to the moment when it is greater than or equal to the maximum allowable temperature again after the cooling rate V_down is calculated. Therefore, when it is detected that the current temperature Temp_current rises to less than 22°C (for example, Temp_current = 21°C), the calculation of the heating rate V_up will not be triggered until the current temperature Temp_current is detected to be equal to 22°C or greater than 22°C again (for example, the current temperature Temp_current = 22.5°C), the heating rate V_up is calculated. In one embodiment, the current temperature for calculating the heating rate V_up is 22.5° C., the previous temperature Temp_previous is the temperature corresponding to the previous moment when the current temperature is 22.5° C., and the heater is turned off for the second time to cool down while calculating the heating rate V_up.

[0100] Obviously, in other embodiments, the calculation time of the cooling rate V_down in the prediction stage can also be calculated again after the current temperature is less than or equal to the minimum allowable temperature for multiple times, such as twice or three times; similarly, the calculation time of the heating rate V_up can also be calculated again after the current temperature is greater than or equal to the maximum allowable temperature for multiple times, such as three or four times; however, the prediction stage consumes too much time, which will obviously reduce the efficiency of adjusting the room temperature to the set temperature.

[0101] S4: According to the heating rate V_up, the cooling rate V_down and the amplitude error Error_target1, the heating time OnTime_balance and the cooling time OffTime_balance required by the HVAC system in the control stage are calculated respectively. Among them, the heating time OnTime_balance refers to the heating time of the HVAC system, which can be the start-up time of the heater; the cooling time OffTime_balance refers to the cooling time of the HVAC system, which can be the shutdown time of the heater.

[0102] The calculation of the heating time OnTime_balance is based on the following formula:

[0103]

[0104] The calculation of the cooling time OffTime_balance is based on the following formula:

[0105]

[0106] In this embodiment, Figure 1 As shown in the figure, if the amplitude error Error_target1 is 1.5℃, the amplitude error interval width Error_target is 3℃, which is twice the amplitude error Error_target1; and the current temperature Temp_current is controlled within 1.5℃ above and below the set temperature Temp_target. Since the set temperature Temp_target is 20℃, the current temperature Temp_current is controlled between 18.5℃ and 21.5℃, so that the current temperature is controlled within the range of the amplitude error; wherein 18.5℃ and 21.5℃ are the lowest temperature and the highest temperature within the range of the amplitude error, respectively. The amplitude error Error_target1 can be manually set or modified according to user needs: if you need to improve the comfort level, reduce the amplitude error Error_target1; if you increase the amplitude error Error_target1, you can reduce the frequency of temperature adjustment and thus reduce energy consumption.

[0107] S5: When the current temperature meets the first control condition, exit the prediction stage and enter the control stage. The first control condition includes that the current temperature reaches the first temperature control condition; when the first control condition is met, the most recent temperature control state of the HVAC system is maintained, that is, the temperature is kept rising or falling.

[0108] The first control condition is specifically that when the HVAC system is in the prediction stage, the heating rate V_up and the cooling rate V_down have been triggered and calculated and are in the cooling state. During the cooling process after the heating rate V_up is calculated, when the current temperature Temp_current is equal to the set temperature Temp_target or is less than the set temperature Temp_traget for the first time, the prediction stage is exited and the control stage is entered at the same time, and the HVAC system continues to maintain the cooling state. In this embodiment, the first temperature control condition is that the current temperature is equal to or less than the set temperature for the first time; wherein, the first time less than the set temperature refers to the moment when the current temperature is less than the set temperature for the first time when the current temperature updated according to the temperature measurement period is compared with the set temperature during the cooling process.

[0109] like Figure 1As shown, in the prediction stage, after the cooling rate V_down and the heating rate V_up are calculated and obtained respectively, the heater of the HVAC system is turned off again and is in the cooling state. Then the temperature will continue to rise to the highest temperature and then begin to gradually decrease. When the current temperature is greater than the set temperature Temp_target, for example, 21°C, it will not exit the prediction stage until it is detected that the current temperature Temp_current is equal to the set temperature Temp_target, that is, equal to 20°C. At this time, the HVAC system is controlled to exit the prediction stage and enter the control stage at the same time. Obviously, when judging whether the current temperature Temp_current reaches the set temperature Temp_target during the cooling process, since the current temperature Temp_current is collected once every temperature measurement period Time_unit, the collected current temperature Temp_current is not necessarily exactly equal to the set temperature Temp_target, but may also be less than the set temperature Temp_target; therefore, when the current temperature Temp_current is collected for the first time less than the set temperature Temp_target, for example, 19.7°C, the prediction stage ends and enters the control stage at the same time.

[0110] S6: After entering the control stage, the continuous heating time and continuous cooling time of the HVAC system are controlled according to the heating time OnTime_balance and the cooling time OffTime_balance, so as to realize the heating and cooling of the HVAC system respectively. The current temperature Temp_current is kept within the range of the amplitude error Error_target1 of the set temperature Temp_target, that is, Temp_target-Error_target1≤Temp_current≤Temp_target+Error_target1. Among them, realizing the heating and cooling of the HVAC system respectively means that the heating and cooling of the HVAC system are controlled alternately and cyclically according to the heating time and the cooling time.

[0111] like Fig. 9 As shown, step S6 specifically includes three steps S61-S63:

[0112] S61: When the collected current temperature Temp_current is less than or equal to the set temperature Temp_target, exit the prediction phase and enter the control phase at the same time.

[0113] S62: After entering the control stage, the HVAC system is kept cooling down, and the continuous cooling time is the product of the cooling time and the first coefficient.

[0114] Taking the heater as an example, keep the heater turned off so that its continuous cooling time is the product of the cooling time and the first coefficient, that is, the product of the cooling time OffTime_balance of the heater and the first coefficient. In this embodiment, the first coefficient is 0.5, and the continuous cooling time is 0.5*cooling time OffTime_balance. Obviously, the value of the first coefficient can be adjusted accordingly according to the specific application scenario of the HVAC system.

[0115] like Figure 1 In the embodiment shown, according to the calculation formula of the cooling time OffTime_balance, the cooling time is basically equivalent to the continuous off time of the heater when the temperature drops from 21.5°C to 18.5°C; similarly, according to the calculation formula of the heating time OnTime_balance, the heating time is basically equivalent to the continuous start-up time of the heater when the temperature rises from 18.5°C to 21.5°C. Therefore, when the temperature drops from 20°C to 18.5°C, the time required to turn off the heater is roughly 0.5 times the cooling time OffTime_balance.

[0116] S63: Then the HVAC system is controlled to perform alternating heating and cooling, the continuous heating time is the product of the heating time and the second coefficient, and the continuous cooling time is the product of the cooling time and the third coefficient.

[0117] In this embodiment, the second coefficient and the third coefficient are both 1. Figure 1As shown, before entering the control stage, the room temperature in the room has dropped to 20°C, or the room temperature is close to below 20°C; obviously, the temperature measurement cycle can be adjusted to basically control the moment of entering the control stage to be close to the set temperature. In the control stage, the heater is kept turned off, and after the first 0.5*cooling time OffTime_balance, the room temperature in the room is started to heat up before it drops to the lowest temperature of 18.5℃. The temperature will first drop to close to the lowest temperature of 18.5℃ before it starts to heat up; after the heater is started to keep heating up and lasting for twice the heating time OnTime_balance, the heater is turned off before the temperature rises to the highest temperature of 21.5℃, and it lasts for twice the cooling time OffTime_balance. Next, the temperature will first rise to close to the highest temperature of 21.5℃ before it starts to cool down again, and the heater is started again and kept heating up and lasting 1 times the heating time OnTime_balance; the heater is then started and turned off in a cycle, so that the current temperature Temp_current collected in the room is always maintained within the amplitude error Error_target1 range of the set temperature Temp_target, that is, between 18.5℃ and 21.5℃. Obviously, the values ​​of the second coefficient and the third coefficient can be adjusted accordingly according to the specific application scenario of the HVAC system.

[0118] It should be noted that during the control stage, although the room temperature may drop below the minimum temperature of 18.5°C and the heater is turned off for 0.5 times the cooling time OffTime_balance after the temperature drops to less than 20°C, the error is small and the perceived temperature is basically the same, so it can be ignored.

[0119] The present invention also provides a HVAC system controller, which adopts the temperature control method of the HVAC system.

[0120] Example 2

[0121] like Figure 2 As shown, the difference between it and Example 1 is that the process after calculating the heating rate V_up and the cooling rate V_down is different. That is, when the current temperature collected satisfies the second control condition, the prediction stage is exited and the control stage is entered. Among them, satisfying the second control condition includes that the current temperature reaches the second temperature control condition; when the second control condition is satisfied, the most recent temperature control state of the HVAC system is maintained at the same time, that is, the heating or cooling state is maintained.

[0122] In this embodiment, the second temperature control condition is that, during the cooling process after the heating rate V_up is calculated, the current temperature is equal to or is less than the sum of the set temperature and the amplitude error Error_target1 for the first time; wherein, being less than the sum of the set temperature and the amplitude error Error_target1 for the first time refers to the moment when, during the cooling process, the current temperature updated according to the temperature measurement cycle is compared with the set temperature, and the current temperature is less than the sum of the set temperature and the amplitude error Error_target1 for the first time.

[0123] The specific steps of differentiation are:

[0124] S5: Control the HVAC system to cool down until the current temperature Temp_current is less than or equal to the sum of the set temperature and the amplitude error Error_target1, that is, when it is equal to or less than 21.5°C for the first time, exit the prediction stage and enter the control stage.

[0125] S61: Keep the HVAC system cooling down, and the cooling down time is the product of the cooling down time OffTime_balance and the first coefficient.

[0126] S62: Then the HVAC system is controlled to perform alternating heating and cooling, the continuous heating time is the product of the heating time OnTime_balance and the second coefficient, and the continuous cooling time is the product of the cooling time OffTime_balance and the third coefficient.

[0127] Among them, the first coefficient, the second coefficient and the third coefficient are all 1.

[0128] Example 3

[0129] like Figure 3 As shown, the difference between it and Example 1 is that the process after calculating the heating rate V_up and the cooling rate V_down is different. That is, when the current temperature is collected to meet the third control condition, the prediction stage is exited and the control stage is entered. Among them, meeting the third control condition includes that the current temperature reaches the third temperature control condition; when the third control condition is met, the most recent temperature control state of the HVAC system is changed, that is, the temperature reduction state is adjusted to the temperature increase state.

[0130] In this embodiment, the third temperature control condition is that, during the cooling process after the heating rate V_up is calculated, the current temperature is equal to or is less than the difference between the set temperature and the amplitude error Error_target1 for the first time; wherein, being less than the difference between the set temperature and the amplitude error Error_target1 for the first time refers to the moment when, during the cooling process, the current temperature updated according to the temperature measurement cycle is compared with the set temperature, and the current temperature is less than the difference between the set temperature and the amplitude error Error_target1 for the first time.

[0131] The specific steps of differentiation are:

[0132] S5: Control the HVAC system to cool down until the current temperature Temp_current is less than or equal to the difference between the set temperature and the amplitude error Error_target1, that is, when it is equal to or less than 18.5°C for the first time, exit the prediction stage and enter the control stage.

[0133] S61: Control and maintain the heating system to heat up, and the continuous heating time is the product of the heating time OnTime_balance and the first coefficient.

[0134] S62: Then the HVAC system is controlled to perform alternating cooling and heating, the continuous cooling time is the product of the cooling time OffTime_balance and the second coefficient, and the continuous heating time is the product of the heating time OnTime_balance and the third coefficient.

[0135] Among them, the first coefficient, the second coefficient and the third coefficient are all 1.

[0136] Example 4

[0137] The difference between this embodiment and Example 1 is that, in the process of controlling the working state of the heater according to the heating time OnTime_balance and the cooling time OffTime_balance, the change of the external ambient temperature, such as the change of ambient temperature during the day and night, the change of ambient temperature during winter and summer, or the power drop caused by the aging of the refrigerator / heater, and other external interferences affect the temperature control of the HVAC system. Therefore, after entering the control stage, when the second prediction condition is reached, the control stage will be exited and the prediction stage will be entered again to improve the anti-interference and control accuracy of the system. At this time, the prediction condition is the second prediction condition.

[0138] Preferably, the second prediction condition includes the following conditions:

[0139] In the control phase, when the peak value Temp_top of the current temperature Temp_current is continuously collected to be greater than the maximum allowable temperature for a first set number of times, the control phase is exited and the prediction phase is re-entered.

[0140] During the operation of the HVAC system, specifically in the control stage, the peak value Temp_top of the current temperature will be determined, confirmed and stored. In the control stage, the determination, confirmation and storage of the peak value Temp_top can be further limited, and the peak value Temp_top can be determined, confirmed and stored only when the current temperature Temp_current is greater than the sum of the set temperature Temp_target and the amplitude error Error_target1. Among them, the first set number of times is three times, such as Fig. 9 As shown, the second prediction condition for exiting the control stage is specifically: when three consecutive peak values ​​are greater than the maximum allowable temperature, exit the control stage and enter the prediction stage from the time point when the third peak value is obtained, and set the run flag Runflag of the control stage to 0; otherwise, after waiting for a temperature measurement cycle Temp_unit, continue to judge whether the peak value Temp_top of the current temperature meets the second prediction condition during the control stage. Among them, in one embodiment, the method for judging the peak value is as follows, A, B, C are the current temperatures Temp_current collected by any three consecutive temperature measurement cycles Temp_unit, when it is judged that the temperature value of point C is less than the temperature value of point B, judge whether the temperature value of point A is also less than the temperature value of point B, if the temperature values ​​of points A and C are both less than the temperature value of point B, then the temperature value of point B is determined to be the peak value. The above method for determining the peak value is one of the embodiments, and there are obviously other judgment methods.

[0141] During the alternating control of heating and cooling in the control phase, if the run flag bit Reunflag is not 1, that is, it is determined that the second prediction condition in the control phase is met, then the control phase is exited and the prediction phase is re-entered; if the run flag bit Runflag is 1, then the control phase is still maintained, and the alternating control of heating and cooling is continued. The first set number of times and the run flag bit can be set as needed.

[0142] like Figure 4As shown, when the interference is encountered in the control stage but the second prediction condition is not met, that is, the room temperature (i.e., the current temperature) is greater than 21.5°C and less than the maximum allowable temperature of 22°C, at this time, since the temperature error is within the controllable range, the heater is still started and shut down according to the control process of Example 1. When the interference causes the temperature error to gradually exceed the controllable range, that is, when the peak value of the room temperature is greater than the maximum allowable temperature of 22°C for three consecutive times, the control stage is exited and the prediction stage is entered, and the heater is in the off state; then, when the current temperature Temp_current is still greater than or equal to 18.5°C, since the heater is in the off state, it is only necessary to keep the heater turned off for cooling; until the current temperature Temp_current is equal to 18°C ​​or less than 18°C ​​for the first time, the cooling rate V_down is calculated, and the heater is started for heating; then, when the current temperature Temp_current is equal to 22°C or greater than 22°C for the first time, the heating rate V_up is calculated, and the subsequent prediction stage and control stage processes are the same as those in Example 1, which will not be repeated here.

[0143] After re-entering the prediction stage, the new heating rate V_up and the new cooling rate V_down under the current environment will be recalculated, so new heating time and cooling time will be obtained to ensure that the subsequent control stage is adapted to the current changing environment, thereby making the subsequent temperature control more accurate and the temperature control consistency better.

[0144] Example 5

[0145] The difference between this embodiment and embodiment 4 is that, preferably, the second prediction condition includes the following conditions:

[0146] In the control phase, when the valley value of the current temperature Temp_current is continuously collected to be less than the minimum allowable temperature for a second set number of times, the control phase is exited and the prediction phase is re-entered.

[0147] like Fig. 9 As shown, in this embodiment, the second set number of times is three times. When the valley value of the current temperature Temp_current is collected three times in succession and is less than the minimum allowable temperature, the control phase will be exited and the prediction phase will be entered, and the run flag Runflag of the control phase will be set to 0; otherwise, after waiting for a temperature measurement cycle Time_unit, continue to determine whether the current temperature meets the second prediction condition during the control phase.

[0148] Since the temperature enters the heating state after the valley value of the current temperature Temp_current is collected three times in a row and is less than the minimum allowable temperature, the temperature will gradually rise. Therefore, after re-entering the prediction stage, the heating rate V_up can be calculated first and then the cooling rate V_down. Of course, it is not ruled out that when the temperature is in a downward trend, the cooling rate V_down is calculated first and then the heating rate V_up is calculated.

[0149] During the heating and cooling alternating control process in the control phase, if the run flag Runflag is not 1, that is, it is judged that the second prediction condition in the control phase is met, the control phase is exited and the prediction phase is re-entered; if the run flag Runflag is 1, the heating and cooling alternating control in the control phase is continued. The second set number of times and the run flag can be set as needed.

[0150] During the operation of the HVAC system, the valley value Temp_button of the current temperature will be judged, confirmed and stored. In the control stage, the judgment, confirmation and storage of the valley value can be further limited. The valley value can be judged, confirmed and stored only when the current temperature is less than the difference between the set temperature and the amplitude error Error_target1. Among them, the corresponding valley value Temp_button when exiting the control stage is determined by the following specific method: when three consecutive valley values ​​are less than the minimum allowable temperature, exit the control stage from the time point obtained from the third valley value and enter the prediction stage. Among them, in one embodiment, the method for judging the valley value is as follows: A1, B1, and C1 are the current temperatures Temp_current collected by any three consecutive temperature measurement cycles Time_unit. When it is judged that the temperature value of point C1 is greater than the temperature value of point B1, it is judged whether the temperature value of point A1 is also greater than the temperature value of point B1. If the temperature values ​​of points A1 and C1 are both greater than the temperature value of point B1, the temperature value of point B1 is judged to be the valley value Trmp_button. The above method for determining the valley value Trmp_button is one of the embodiments, and there are obviously other judgment methods.

[0151] Example 6

[0152] The difference between this embodiment and embodiment 4 is that, preferably, the second prediction condition includes the following conditions:

[0153] In the control stage, the current error Error_current is obtained. When the current error Error_current is greater than the product of the amplitude error Error_target1 and the threshold coefficient, the control stage is exited and the prediction stage is re-entered.

[0154] like Fig. 9As shown, in this embodiment, the threshold coefficient is 3. In the control stage, when controlling the continuous working time or continuous closing time of the heater, the current error Error_current is obtained in real time. When the current error Error_current is greater than 3*amplitude error Error_target1, the run flag Runflag of the control stage is set to 0; otherwise, after waiting for a temperature measurement cycle Time_unit, it is continued to determine whether the current error of the heater meets the second prediction condition in the control stage.

[0155] During the heating and cooling alternating control process in the control phase, if the run flag Runflag is not 1, that is, it is judged that the second prediction condition in the control phase is met, the control phase is exited and the prediction phase is re-entered; if the run flag Runflag is 1, the heating and cooling alternating control in the control phase is continued. Among them, the threshold coefficient and the run flag can be set according to the specific application scenario.

[0156] The current error Error_current is calculated using the following formula:

[0157] Error_current=Temp_top-Temp_button

[0158] Among them, the peak value Temp_top is the highest temperature when the current temperature Error_currnet is greater than the maximum allowable temperature each time; Temp_button is the previous lowest temperature corresponding to the current temperature Temp_current being greater than the maximum allowable temperature each time. Figure 5 As shown, in the control stage, the highest and lowest temperatures of the HVAC system are collected and stored in real time, and each highest temperature is recorded as a peak value Temp_top, and each lowest temperature is recorded as a valley value Temp_button. When the current error Error_currnet is calculated to be greater than 3*amplitude error Error_target1, the moment corresponding to the peak value Temp_top of the current error Error_current is calculated to be the moment to exit the control stage and re-enter the prediction stage. In the control stage, the corresponding peak value Temp_top and valley value Temp_button can be determined in the same way as in Examples 4 and 5. Figure 5 It is only used as a node diagram for temperature change trend, prediction stage and control stage.

[0159] Example 7

[0160] The difference between it and Example 6 is that the calculation conditions for the calculation of the current error Error_current are further limited, and the current error Error_current is calculated only when the calculation conditions are met. The calculation conditions are that the current error Error_current is calculated only when the current temperature Temp_current is less than the difference between the set temperature Temp_target and the amplitude error Error_target1, or the current temperature Temp_current is greater than the sum of the set temperature Temp_target and the amplitude error Error_target1. This is because when the current temperature Temp_current is within the amplitude error Error_target1 range of the set temperature Temp_target, the current error Error_current will not exceed the threshold coefficient of the amplitude error Error_target1 in theory, so data redundancy can be reduced and the operating efficiency of the system can be improved.

[0161] Example 8

[0162] This embodiment is based on the embodiment 1, but the difference is that the HVAC system includes a heater and a cooler. When the temperature rises, the heater is started, the cooler is in the off state, and the heating time is the heater start time; when the temperature drops, the heater is turned off for natural cooling, and the cooler is started for active cooling, and the cooling time is the heater off time and also the cooler start time. The cooling rate of this embodiment is obviously greater than the cooling rate in the embodiment 1, and the heater off time is less than the heater off time in the embodiment 1. In this case, the corresponding HVAC system is HVACR.

[0163] Example 9

[0164] This embodiment is based on the embodiment 1, but the difference lies in the different application scenarios when the HVAC system is used, that is, when the ambient temperature is greater than the set temperature Temp_target (for example, in summer, the heater is never running), the HVAC system controller is run, and at this time the cooler is controlled to cool down the room temperature in the room. The HVAC system includes a heater and a cooler. Therefore, step S2 is:

[0165] When entering the prediction stage, when the current temperature Temp_current is collected and is lower than the minimum allowable temperature, the HVAC system is controlled to increase the temperature, that is, the cooler is turned off for natural temperature increase, and the heater is in the off state; otherwise, the HVAC system is controlled to cool down, that is, the cooler is controlled or kept started for cooling, and the heater is in the off state.

[0166] like Fig.11As shown, when entering the prediction stage, the size of the collected current temperature Temp_current is first determined. When the collected current temperature Temp_current is less than or equal to the minimum allowable temperature, the HVAC system is controlled to heat up, and the temperature will continue to drop from the minimum allowable temperature to the lowest temperature and then start to rise, that is, the subsequent heating process starts from below the minimum allowable temperature; after controlling the HVAC system to heat up, when it is determined that the collected current temperature Temp_current is greater than or equal to the maximum allowable temperature, the heating rate V_up at the current moment is calculated and the HVAC system is controlled to cool down, and the temperature will continue to rise from the maximum allowable temperature to the highest temperature and then start to drop; after controlling the HVAC system to cool down, when it is determined that the collected current temperature Temp_current is less than or equal to the minimum allowable temperature for the second time, the cooling rate V_down at the current moment is calculated and the HVAC system is controlled to heat up.

[0167] like Fig.10 As shown, in the prediction stage, the heating time OnTime_balance and the cooling time OffTime_balance required by the HVAC system are calculated according to the heating rate V_up, the cooling rate V_down and the amplitude error Error_target1. At the same time, after the cooling rate V_down is calculated, the HVAC system will be controlled to heat up until the current temperature Temp_current is collected to meet the fourth control condition, and then the prediction stage is exited and the control stage is entered. Although the HVAC system will continue to maintain the heating state, that is, keep the cooler closed for natural heating after the cooling rate V_down is calculated, the temperature will continue to drop to the lowest temperature and then rise due to thermal inertia. The current temperature Temp_current will be collected and updated every temperature measurement period Time_unit until the current temperature Temp_current is collected to meet the fourth temperature control condition, then the HVAC system will be kept heating up, that is, the cooler will be closed, and the control stage will be entered.

[0168] The fourth control condition is specifically that when the HVAC system is in the prediction stage, the heating rate V_up and the cooling rate V_down have been triggered and calculated and are in the heating state. During the heating process after the cooling rate V_down is calculated, when the current temperature Temp_current is equal to the set temperature Temp_target or is greater than the set temperature Temp_target for the first time, the prediction stage is exited and the control stage is entered at the same time. At this time, the HVAC system continues to maintain the heating state. The fourth control condition includes that the current temperature reaches the fourth temperature control condition.

[0169] like Fig.11As shown, in this embodiment, the fourth temperature control condition is that during the heating process after the cooling rate V_down is calculated, when the current temperature Temp_target is equal to the set temperature Temp_target or is greater than the set temperature Temp_target for the first time. Wherein, the first time greater than the set temperature refers to the moment when the current temperature is greater than the set temperature for the first time during the heating process, when the current temperature updated according to the temperature measurement period is compared with the set temperature.

[0170] After entering the control stage, the HVAC system is kept heating up, and the continuous heating time is the product of the first coefficient and the heating time OnTime_balance; then the HVAC system is controlled to alternately cool down and heat up, and the continuous cooling time is the product of the cooling time OffTime_balance and the second coefficient, and the continuous heating time is the product of the heating time OnTime_balance and the third coefficient. Then the cooler is started and shut down in sequence to control the current temperature Temp_current within the amplitude error Error_target1 of the set temperature Temp_target.

[0171] In which, taking the use of the HVAC system in summer as an example, the heating time OnTime_balance refers to the time when the cooler is turned off and kept turned off, i.e., the natural heating time; the cooling time OffTime_balance refers to the time when the cooler is continuously started and kept started, i.e., the cooling time. The calculation of the heating time OnTime_balance and the cooling time OffTime_balance is the same as that in Example 1, and the values ​​of the first coefficient, the second coefficient, and the third coefficient are also the same as those in Example 1.

[0172] Obviously, the setting of the control conditions can also be adjusted as needed. For example, when the current temperature Temp_current is collected to meet the fifth temperature control condition, the prediction stage can be exited and the control stage can be entered. For example, the fifth temperature control condition is that in the heating process after calculating the cooling rate V_down, when the current temperature Temp_currrent is collected to be equal to or greater than the sum of the set temperature Temp_target and the amplitude error Error_target1 for the first time, at this time, after entering the control stage, the HVAC system is controlled and maintained to cool down, and the continuous cooling time is the product of the cooling time OffTime_balance and the first coefficient, and then the HVAC system is controlled to alternately heat up and cool down, and the continuous heating time is the product of the heating time OnTime_balance and the second coefficient, and the continuous cooling time is the product of the cooling time OffTime_balance and the third coefficient, and then the cooler is started and shut down in sequence. Among them, the first coefficient, the second coefficient and the third coefficient are all 1.

[0173] For another example, when the current temperature Temp_currrent collected satisfies the sixth temperature control condition, the prediction phase is exited and the control phase is entered. That is, the sixth temperature control condition is that during the heating process after calculating the cooling rate v_down, the current temperature Temp_current is equal to or greater than the difference between the set temperature Temp_target and the amplitude error Error_target1 for the first time. At this time, after entering the control phase, the HVAC system is kept heating up, and the continuous heating time is the product of the heating time and the first coefficient; then the HVAC system is controlled to alternately cool down and heat up, and the continuous cooling time is the product of the cooling time and the second coefficient, and the continuous heating time is the product of the heating time and the third coefficient. Among them, the first coefficient, the second coefficient, and the third coefficient are all 1.

[0174] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to those of the present application fall within the protection scope of the present invention.

Claims

1. A temperature control method for a HVAC system, characterized in that: The steps include: Collect the current temperature of the temperature control environment of the HVAC system according to the temperature measurement cycle; Enter the prediction stage to calculate the cooling rate and heating rate of the HVAC system; The cooling rate is calculated as follows: Calculate the temperature change rate when the temperature drops from the previous moment to the current temperature being less than or equal to the minimum allowable temperature in a temperature measurement cycle as the cooling rate; The heating rate is calculated as follows: Calculate the temperature change rate when the temperature rises from the previous moment to the current temperature being greater than or equal to the maximum allowable temperature in a temperature measurement cycle as the heating rate; According to the heating rate, the cooling rate and the amplitude error, respectively calculating the heating time and cooling time required for the HVAC system; Exit the prediction phase and enter the control phase; After entering the control stage, the continuous heating time and continuous cooling time of the HVAC system are controlled according to the heating time and cooling time, so as to realize the heating and cooling of the HVAC system respectively, so that the current temperature is kept within the amplitude error of the set temperature.

2. The temperature control method of the HVAC system according to claim 1, characterized in that: The heating time is calculated as follows: The cooling time is calculated as follows: Among them, Ontime_balance is the heating time, OffTime_balance is the cooling time, V_up is the heating rate, v_down is the cooling rate, and Error_target is the amplitude error interval width, which is twice the amplitude error.

3. The temperature control method of the HVAC system according to claim 1, characterized in that: The step of entering the prediction phase and calculating the cooling rate and heating rate of the HVAC system includes the following steps: Determine whether the current temperature is greater than or equal to the maximum allowable temperature. If so, control the HVAC system to cool down. After the HVAC system is controlled to cool down, it is determined whether the current temperature is less than or equal to the minimum allowable temperature. If the current temperature is less than or equal to the minimum allowable temperature, the HVAC system is controlled to heat up, and the cooling rate is calculated; After controlling the HVAC system to heat up, it is determined whether the current temperature is greater than or equal to the maximum allowable temperature for the second time. If it is greater than or equal to the maximum allowable temperature, the HVAC system is controlled to cool down, and the heating rate is calculated.

4. The temperature control method of a HVAC system according to claim 1, characterized in that: The step of entering the prediction phase and calculating the cooling rate and heating rate of the HVAC system includes the following steps: Determine whether the current temperature is less than or equal to the minimum allowable temperature. If so, control the HVAC system to increase the temperature. After the HVAC system is controlled to heat up, it is determined whether the current temperature is greater than or equal to the maximum allowable temperature. If the current temperature is greater than or equal to the maximum allowable temperature, the HVAC system is controlled to cool down, and the heating rate is calculated; After controlling the HVAC system to cool down, it is determined whether the current temperature is less than or equal to the minimum allowable temperature for the second time. If it is less than or equal to the minimum allowable temperature, the HVAC system is controlled to heat up, and the cooling rate is calculated.

5. The temperature control method of the HVAC system according to claim 3, characterized in that: The step of exiting the prediction phase and entering the control phase at the same time comprises the following steps: when the current temperature collected satisfies the first control condition, exiting the prediction phase and entering the control phase at the same time; The first control condition is that, during the cooling process after calculating the heating rate, when the current temperature is equal to the set temperature or is lower than the set temperature for the first time; Alternatively, when the current temperature collected satisfies the second control condition, the prediction phase is exited and the control phase is entered; The second control condition is that, during the cooling process after the heating rate is calculated, when the current temperature is equal to or less than the sum of the set temperature and the amplitude error for the first time; Alternatively, when the current temperature collected satisfies the third control condition, the prediction phase is exited and the control phase is entered; The third control condition is that, during the cooling process after the heating rate is calculated, when the current temperature is equal to or less than the difference between the set temperature and the amplitude error for the first time.

6. The temperature control method of the HVAC system according to claim 4, characterized in that: The step of exiting the prediction phase and entering the control phase at the same time comprises the following steps: when the current temperature collected satisfies the fourth temperature control condition, exiting the prediction phase and entering the control phase at the same time; The fourth temperature control condition is that, during the heating process after the cooling rate is calculated, when the current temperature is equal to the set temperature or is greater than the set temperature for the first time; Alternatively, when the current temperature collected satisfies the fifth temperature control condition, the prediction phase is exited and the control phase is entered; The fifth temperature control condition is that, during the heating process after the cooling rate is calculated, when the current temperature is equal to or greater than the sum of the set temperature and the amplitude error for the first time; Alternatively, when the current temperature collected satisfies the sixth temperature control condition, the prediction phase is exited and the control phase is entered; The sixth temperature control condition is that, during the heating process after the cooling rate is calculated, when the current temperature is equal to or greater than the difference between the set temperature and the amplitude error for the first time.

7. The temperature control method of a HVAC system according to claim 5 or 6, characterized in that: After entering the control stage; Control the HVAC system to cool down, and the continuous cooling time is the product of the cooling time and the first coefficient; then control the HVAC system to heat up and cool down alternately, and the continuous heating time is the product of the heating time and the second coefficient, and the continuous cooling time is the product of the cooling time and the third coefficient; Alternatively, the HVAC system is controlled to heat up, and the continuous heating time is the product of the heating time and the first coefficient; then the HVAC system is controlled to cool down and heat up alternately, and the continuous cooling time is the product of the cooling time and the second coefficient, and the continuous heating time is the product of the heating time and the third coefficient.

8. The temperature control method of the HVAC system according to claim 7, characterized in that: The HVAC system includes a heater, which is started when the temperature rises, and the heating time is the heater start time; the heater is turned off when the temperature drops, and the temperature drop time is the heater shut-down time; Alternatively, the HVAC system includes a heater and a cooler. When the temperature rises, the heater is started and the cooler is in an off state, and the heating time is equal to the start-up time of the heater. When the temperature drops, the heater is turned off for natural cooling, and the cooler is started for active cooling. The cooling time is equal to the off time of the heater and the start-up time of the cooler.

9. The temperature control method of a HVAC system according to any one of claims 1 to 8, characterized in that: The following steps are also included: The prediction phase begins only after the prediction conditions are met; The prediction condition is a first prediction condition, and the first prediction condition is that the HVAC system controller is running for the first time; Alternatively, the prediction condition is a second prediction condition, and the second prediction condition includes one of the following conditions: In the control stage, when the peak value of the current temperature continuously collected is greater than the maximum allowable temperature for a first set number of times; In the control stage, when the valley value of the current temperature continuously collected is less than the minimum allowable temperature for a second set number of times; In the control stage, the current error is obtained when the current error is greater than the product of the amplitude error and the threshold coefficient.

10. A HVAC system controller, characterized in that: A temperature control method for a HVAC system as described in any one of claims 1 to 9 is adopted.

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