Control method of air-cooled chiller unit, air-cooled chiller unit and air conditioner

Abstract

The invention discloses a control method of an air-cooled chiller unit, the air-cooled chiller unit and an air conditioner. The air-cooled chiller unit comprises n draught fans and a draught fan speed regulator, the draught fan speed regulator is connected with the n draught fans, and the control method comprises the steps that the condensation temperature of the air-cooled chiller unit is obtained; when the condensation temperature is in the ith temperature interval, i fans are controlled to be started; wherein n adjacent temperature intervals are arranged in total, and i is any integer between 1 and n; and the input voltage of the fan speed regulator is controlled according to the condensation temperature so as to control the total power of the i fans. The fan rotating speed adjusting interval can be increased, air volume waste is reduced, the whole machine power is reduced, and therefore the unit energy efficiency is improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of refrigeration, and in particular, to a control method for an air-cooled chiller, an air-cooled chiller, and an air conditioner. Background Art

[0002] The current fan control technology of air-cooled chillers has obvious deficiencies in energy efficiency improvement and dynamic regulation, and it is difficult to meet the requirements of the stability and energy efficiency of the whole unit.

[0003] The existing conventional air-cooled chiller fans mainly include two control methods: one is the hierarchical control of alternating current (AC) fans. The condensation pressure is adjusted hierarchically by starting and stopping several fans, but the fans operate at a fixed power, resulting in large pressure fluctuations and a decrease in energy efficiency as the number increases; the other is the variable frequency control of AC fans. The stepless speed regulation is realized by using an inverter, but the minimum frequency needs to be limited due to insufficient air volume in the low frequency band, the adjustment range is limited, and all fans need to be continuously turned on, resulting in redundant power consumption and high energy consumption.

[0004] In the above related technologies, the hierarchical control causes pressure fluctuations and low energy efficiency due to frequent start and stop, while the variable frequency control, although having high energy efficiency, is limited by the ineffectiveness of low frequency regulation and redundant operation problems. Both of them cannot fully explore the energy-saving potential, and the dynamic response speed, pressure stability, and hardware resource utilization rate are insufficient, making it difficult to meet the existing requirements. Summary of the Invention

[0005] The present invention provides a control method for an air-cooled chiller, an air-cooled chiller, and an air conditioner, so as to greatly increase the fan speed adjustment range, reduce air volume waste, reduce the overall power of the unit, and thus improve the energy efficiency of the unit.

[0006] In a first aspect, an embodiment of the present invention provides a control method for an air-cooled chiller. The air-cooled chiller includes n fans and a fan speed regulator, and the fan speed regulator is respectively connected to the n fans. The control method includes:

[0007] Obtain the condensation temperature of the air-cooled chiller;

[0008] When the condensation temperature is in the i-th temperature range, control the i fans to turn on; where n adjacent temperature ranges are provided in total, and i is any integer between 1 and n;

[0009] In the temperature range where the condensation temperature is located, control the magnitude of the input voltage of the fan speed regulator according to the condensation temperature to control the total power of the i fans.

[0010] Second aspect, an embodiment of the present invention further provides an air-cooled chiller, which includes n fans, a fan speed regulator, and a control module;

[0011] The fan speed regulator is respectively connected to the n fans, and the control module is respectively connected to the n fans and the fan speed regulator; the fan speed regulator is used to control the rotation speeds of the n fans according to the input voltage of the fan speed regulator;

[0012] The control module is used to obtain the condensation temperature of the air-cooled chiller; the control module is further used to control the activation of i fans when the condensation temperature is in the i-th temperature range; where a total of n adjacent temperature ranges are provided, and i is any integer between 0 and n; the control module is further used to control the magnitude of the input voltage of the fan speed regulator according to the condensation temperature in the temperature range where the condensation temperature is located, so as to control the total power of the i fans.

[0013] Third aspect, an embodiment of the present invention further provides an air conditioner, which includes the air-cooled chiller according to any embodiment of the present invention.

[0014] The present invention provides a control method for an air-cooled chiller, the air-cooled chiller, and an air conditioner. The air-cooled chiller includes n fans and a fan speed regulator. The fan speed regulator is respectively connected to the n fans. The control method of the present invention combines temperature hierarchical control and a fan speed regulator to control the rotation speed of the fans. By obtaining the condensation temperature of the air-cooled chiller; when the condensation temperature is in the i-th temperature range, the activation of i fans is controlled, so as to realize hierarchical control of the fan activation according to the condensation temperature, avoid waste of air volume and increase in energy consumption caused by excessive activation of the fans. By controlling the magnitude of the input voltage of the fan speed regulator according to the condensation temperature, the power of each fan is controlled to control the total power of the i fans, further increasing the fan rotation speed adjustment range and reducing waste of air volume. By increasing the fan rotation speed adjustment range, the present invention can meet the air volume requirements of various loads, thereby reducing waste of air volume, reducing the overall power of the unit, and improving the energy efficiency of the unit. Description of the Drawings

[0015] Figure 1 It is a schematic diagram of the relationship between the total power of the fans and the condensation pressure in the prior art using hierarchical control of AC fans;

[0016] Figure 2 It is a schematic diagram of the relationship between the total power of the fans and the condensation pressure in the prior art using variable frequency control of AC fans;

[0017] Figure 3 It is a flowchart of a control method for an air-cooled chiller provided by an embodiment of the present invention;

[0018] Figure 4 A flow chart of another method for controlling an air-cooled chiller provided by an embodiment of the present invention;

[0019] Figure 5 A schematic diagram of a data comparison table provided in an embodiment of the present invention;

[0020] Figure 6 A schematic diagram of another data comparison table provided in an embodiment of the present invention;

[0021] Figure 7 A schematic diagram of the relationship between the total fan power and the condensing pressure provided in an embodiment of the present invention;

[0022] Figure 8 A schematic structural diagram of an air-cooled chiller provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0024] At present, the fan control technology of conventional air-cooled chillers mainly adopts the following two schemes:

[0025] 1. AC fan hierarchical control. This technology uses a fixed number of fans to perform hierarchical start and stop control. Specifically, the unit is equipped with an even number of fans (such as 4 fans), and the unit is graded according to the number of fans. The number of fans is an even number, and the grading rule is an even number, with at least 2 levels and a maximum of 4 levels. The fans are switched on and off according to the condensing pressure through the set deviation, causing the unit pressure to fluctuate. The more fans there are, the more precise the pressure control is. Since the fans cannot adjust their speed, the fan work is fixed, which causes the power of the entire unit to increase. The more fans there are in the unit, the lower the energy efficiency. Take 4 fans and 4 levels as an example. Figure 1 This is a schematic diagram of the relationship between the total fan power and the condensing pressure using AC fan graded control in the related technology. Figure 1The abscissa is the condensation pressure, and the ordinate is the total power of the fans. Each stage corresponds to the start and stop of one fan. The fans are turned on according to the condensation pressure of the unit. The condensation pressure is related to the condensation temperature, and there is a corresponding relationship between the condensation temperature and the condensation pressure. The greater the condensation temperature, the greater the condensation pressure. When the AC fans operate at full load, the power is 2 kW. When all 4 fans are fully open, it is 8 kW. However, this solution has significant drawbacks. The fans can only operate at a fixed power and cannot adjust the output power according to actual needs. As the number of fans turned on increases, the overall energy efficiency (COP) of the unit decreases significantly. For example, when all 4 fans are fully open, the system energy efficiency is lower than that in the low-load condition. And due to the limited adjustment range and the grading rule depending on the number of fans, it is difficult to meet the high-precision temperature control requirements.

[0026] 2. Variable-frequency control of AC fans. This technology uses an inverter to perform stepless speed regulation on the fans. Theoretically, the fan speed can be dynamically adjusted according to the condensation pressure. For example, to ensure the safety of the fans, ordinary AC fan manufacturers recommend 5 Hz as the minimum operating frequency. So when the fans are turned on, there are 46 adjustable frequencies for the fans. It is found in the test that when the fans are at 5 - 29 Hz, the air volume is small, often causing the inverter to load and unload, and the system pressure fluctuates severely. Therefore, it is decided to set 30 Hz as the minimum frequency. When the variable-frequency control starts the fans, after the unit enters automatic adjustment, all fans will be turned on according to the condensation temperature. When the AC fans operate at full load, the power is 2 kW, and the power at the minimum frequency of the fans is 1.2 kW. Figure 2 It is a schematic diagram of the relationship between the total power of the fans with variable-frequency control of AC fans and the condensation pressure in the related technology. Taking 4 fans as an example, as Figure 2 shown, more stable pressure control is achieved through coordinated variable-frequency adjustment, and the overall energy efficiency is better than that of AC grading control. However, in this solution, at some condensation temperatures, the energy efficiency is not as good as that of grading control, such as 39°C, 44°C, 49°C, etc. In addition, there is redundancy in the full-fan operation. In the automatic adjustment mode, all fans need to remain turned on. Even when operating at a reduced frequency under low load, there is still unnecessary power loss, and the energy-saving potential is not fully exploited.

[0027] The present invention combines to solve the problems in the related technology, eliminate useless work, and reduce the fan power and improve the energy efficiency while ensuring that the air volume of the unit is satisfied.

[0028] To solve the above problems in the related technology, while ensuring that the air volume of the unit is satisfied, reducing the fan power and improving the energy efficiency, the embodiment of the present invention provides a control method for an air-cooled chiller. This embodiment is applicable to controlling an air-cooled chiller. Figure 3 It is a flowchart of a control method for an air-cooled chiller provided by an embodiment of the present invention. The air-cooled chiller includes n fans and a fan speed regulator. The fan speed regulator is respectively connected to the n fans. As Figure 3 shown, the control method includes:

[0029] S110. Obtain the condensation temperature of the air-cooled chiller.

[0030] Among them, the condensation temperature of the air-cooled chiller is the saturation temperature when the refrigerant vapor in the condenser of the air-cooled chiller condenses under a certain pressure. The condensation temperature is directly related to the ambient temperature, cooling air volume and system load. The condensation temperature can be obtained by converting the data measured by the high-pressure sensor in the condenser. The condensation pressure is the saturation pressure corresponding to the refrigerant during the condensation process, which is determined by the condensation temperature. The condensation pressure increases exponentially with the increase of the condensation temperature. When the condensation temperature is too high, the condensation pressure of the system also increases. The core goal of fan control in the related technology is to stabilize both of them in the optimal range (such as 35-45 °C) by adjusting the heat dissipation air volume of the condenser, so as to achieve maximum energy efficiency and system reliability. The pressure fluctuation caused by the defect in the related technology is essentially the manifestation of insufficient temperature control accuracy.

[0031] Specifically, the air-cooled chiller includes n fans and a fan speed governor, where n is a positive integer. The fan speed governor can be used to control the rotation speed of various types of electric fans, including centrifugal fans, exhaust fans, propeller fans and axial fans. In the embodiment of the present invention, the fan speed governor can control the rotation speed of the fans, and the rotation speed of the fans can be finely adjusted by controlling the input voltage of the fan speed governor. The fan speed governor is respectively connected to n fans, and the fan speed governor can control the power of n fans at the same time. By obtaining the condensation temperature of the air-cooled chiller, and there is a corresponding relationship between the condensation pressure and the condensation temperature, the condensation pressure of the air-cooled chiller is controlled by controlling the opening of the fans and the combination of the fan speed governor. In the embodiment of the present invention, by adding a fan speed governor, hierarchical control and one fan speed governor are combined to control the condensation pressure of the air-cooled chiller; under hierarchical control, the fan speed governor is used to control the air volume of the fans to be refined to the saturation pressure corresponding to the condensation temperature, and the rotation speed of the fans is matched and adjusted in a large range to reduce air volume waste, thereby reducing the overall power of the machine, improving energy efficiency and eliminating useless work.

[0032] S120. When the condensation temperature is in the i-th temperature range, control the opening of the i fans; where a total of n adjacent temperature ranges are set, and i is any integer between 1 and n.

[0033] The temperature interval corresponds to the number of fans. The number of fans and the temperature interval are both n. For example, if the number of fans is 4, the temperature interval is also 4; if the number of fans is 6, the temperature interval is also 6. The n temperature intervals are adjacent and arranged in sequence to form a total temperature range of the condensing temperature. The total temperature range of the condensing temperature can be set according to factors such as the ambient temperature. Optionally, the total temperature range of the condensing temperature is 31°C-50°C, with a total of 4 temperature intervals. The first temperature interval is (31, 35], the second temperature interval is (35, 40], the third temperature interval is (40, 45], and the fourth temperature interval is (45, 50].

[0034] Specifically, when the condensing temperature is in the i-th temperature interval, the i fans are controlled to be turned on, and then the fan speed regulator performs more precise speed regulation. Exemplarily, the number of fans and the temperature intervals are both 4. When the condensing temperature is in the second temperature interval, the two fans are controlled to be turned on, and then the fan speed regulator performs more precise speed regulation to avoid excess waste of air volume; if the condensing temperature rises from the second temperature interval to the third temperature interval, the three fans are controlled to be turned on, and then the fan speed regulator performs more precise speed regulation to avoid excess waste of air volume. By controlling the fan opening according to the condensing temperature, so that the number of fans turned on matches the condensing pressure, the waste of air volume and increased energy consumption caused by too many fans turned on can be avoided.

[0035] S130. In the temperature range where the condensing temperature is located, the input voltage of the fan speed regulator is controlled according to the condensing temperature to control the total power of i fans.

[0036] Among them, the power of each fan can be controlled by controlling the size of the input voltage of the fan speed regulator, thereby controlling the speed of each fan and the air volume generated. Exemplarily, when i=2, that is, the condensing temperature is in the second temperature interval, the opening of the two fans is controlled, and the input voltage of the fan speed regulator is controlled to be 6V, so that the power of the two fans turned on is 1.4, so as to control the total power of the two fans to be 2.8. If the condensing temperature continues to increase in the second temperature interval, the input voltage of the fan speed regulator is adjusted to increase, so that the power of the two fans turned on increases, and the total power of the two fans increases. Optionally, in each temperature interval, the input voltage of the fan speed regulator increases with the increase of the condensing temperature until the maximum input voltage of the fan speed regulator is reached.

[0037] Specifically, a data comparison table of condensation temperature, temperature range, input voltage of the fan speed governor, and total power of the turned-on fans can be established in advance, and the total power of the turned-on fans is controlled by combining hierarchical control and the fan speed governor. When the obtained condensation temperature is within the corresponding temperature range in the data comparison table, the number of fans corresponding to this temperature range is turned on, and the magnitude of the input voltage of the fan speed governor is controlled to be the input voltage of the fan speed governor corresponding to the condensation temperature in the data comparison table, so that the obtained condensation temperature matches the total power of the turned-on fans. Exemplarily, the second temperature range is (35, 40]. When the obtained condensation temperature is 36 °C and is within the second temperature range, 2 fans are turned on, and the input voltage of the fan speed governor corresponding to 36 °C in the data comparison table is 6 V, then the input voltage of the fan speed governor is controlled to be 6 V, so that the power of each of the 2 turned-on fans is 1.4, and the total power of the 2 fans is 2.8. If the condensation temperature changes within the second temperature range, the input voltage of the fan speed governor is continuously adjusted according to the data comparison table to control the total power of the 2 turned-on fans to match the condensation pressure. On the basis of hierarchically controlling the number of turned-on fans, by controlling the magnitude of the input voltage of the fan speed governor according to the condensation temperature, the power of each fan is controlled to control the total power of i fans, further increasing the fan speed adjustment range and reducing air volume waste.

[0038] In addition, since the embodiment of the present invention controls the turning-on of fans hierarchically and controls the magnitude of the input voltage of the fan speed governor according to the condensation temperature, the fan speed adjustment range is greatly increased, so that the air volume required for various loads can be satisfied, and the pressure of the air-cooled chiller is stabilized. In addition, by the above method, the problems of air volume waste and increased energy consumption caused by too many turned-on fans can be avoided, and a suitable power can be matched under each condensation pressure, greatly increasing the fan control range, so that the fan can be more energy-efficient under different loads of the unit and reduce useless work.

[0039] The embodiment of the present invention provides a control method for an air-cooled chiller. The air-cooled chiller includes n fans and a fan speed governor, and the fan speed governor is respectively connected to the n fans. The control method of the present invention combines temperature hierarchical control and the fan speed governor to control the fan speed. By obtaining the condensation temperature of the air-cooled chiller; when the condensation temperature is within the i-th temperature range, i fans are controlled to be turned on, so as to realize hierarchical control of the turned-on fans according to the condensation temperature, avoiding air volume waste and increased energy consumption caused by too many turned-on fans. By controlling the magnitude of the input voltage of the fan speed governor according to the condensation temperature, the power of each fan is controlled to control the total power of i fans, further increasing the fan speed adjustment range and reducing air volume waste. By increasing the fan speed adjustment range, the present invention can meet the air volume requirements for various loads, thereby reducing air volume waste, reducing the overall machine power, and improving the energy efficiency of the unit.

[0040] In an embodiment of the present invention, in order to further achieve precise control of an air-cooled chiller, another control method for the air-cooled chiller is provided. Figure 4 As shown in the flowchart of another control method for the air-cooled chiller provided by the embodiment of the present invention, Figure 4 the control method includes:

[0041] S210. Obtain the condensation temperature of the air-cooled chiller.

[0042] S220. When the condensation temperature is within the i-th temperature range, control the i fans to turn on; where a total of n adjacent temperature ranges are provided, and i is any integer between 1 and n.

[0043] S230. Establish a data comparison table of the condensation temperature and the input voltage of the fan speed governor.

[0044] Specifically, in the data comparison table, each condensation temperature has a corresponding input voltage of the fan speed governor. In addition, in the data comparison table, each condensation temperature also has a corresponding temperature range, the corresponding number of fans turned on, and the corresponding total power of the fans turned on. By controlling the air-cooled chiller through the data comparison table, the speed regulation range of the air-cooled chiller can be increased, the air volume required for various loads can be satisfied, the waste of air volume can be reduced, the overall power of the machine can be reduced, and the energy efficiency of the unit can be improved.

[0045] Optionally, determine the total power of the i fans according to the input voltage of the fan speed governor and the number of fans i turned on to obtain a power comparison table; set the input voltage of the fan speed governor corresponding to different condensation temperatures in different temperature ranges; and associate the input voltage of the fan speed governor and the condensation temperature in the power comparison table to obtain a data comparison table.

[0046] Specifically, the input voltage of the fan speed governor has a corresponding relationship with the power of the fan. For example, when the input voltage of the fan speed governor is 6V, the power of each turned-on fan is 1.4KW. As the input voltage of the fan speed governor increases, the power of each turned-on fan also increases. Therefore, when the number of turned-on fans and the input voltage of the fan speed governor are known, the total power of the fans corresponding to different numbers of turned-on fans can be determined, and then a power comparison table can be obtained. In the power comparison table, the total power of i fans has a corresponding relationship with the input voltage of the fan speed governor. Since the temperature range has a corresponding relationship with the number of turned-on fans, the number of turned-on fans can be obtained according to the temperature range where the condensation temperature is located. Since the temperature range where the condensation temperature is located and the number of turned-on fans are known, the input voltage of the fan speed governor corresponding to different condensation temperatures in different temperature ranges can be set, so that in different temperature ranges, the total power of the turned-on fans corresponds to different condensation temperatures, and the total power of the turned-on fans can also correspond to the input voltage of the fan speed governor in different temperature ranges. Therefore, by associating the input voltage of the fan speed governor and the condensation temperature in the power comparison table, a data comparison table can be obtained.

[0047] S240. Adjust the magnitude of the input voltage of the fan speed governor according to the condensation temperature and the data comparison table to control the total power of i fans.

[0048] Specifically, since the data comparison table already reflects the corresponding relationship among the condensation temperature, the temperature range, the number of turned-on fans, and the input voltage of the fan speed governor, after obtaining the condensation temperature, the number of corresponding turned-on fans and the corresponding input voltage of the fan speed governor can be determined in the data comparison table, and the input voltage of the fan speed governor can be adjusted to the corresponding magnitude according to turning on the corresponding number of fans to control the total power of i fans, so that the total power of i fans meets the corresponding condensation pressure, thereby greatly increasing the fan speed adjustment range, reducing the waste of air volume, being able to meet the air volume requirements of various loads, thus reducing the waste of air volume, reducing the overall power of the unit, improving the energy efficiency of the unit, and further solving the problems of poor energy efficiency, insufficient dynamic response, and redundant fan operation in the existing control method.

[0049] Taking an air-cooled chiller with 4 fans as an example, Figure 5 is a schematic diagram of a data comparison table provided by an embodiment of the present invention. Refer to Figure 5 , in the embodiment of the present invention, n = 4. The air-cooled chiller has 4 temperature ranges and 4 fans, and the fan speed governors are respectively connected to the 4 fans. In the embodiment of the present invention, when the condensation temperature is in the i-th temperature range, controlling the turning on of i fans includes:

[0050] When the condensation temperature is within the first temperature range, control one fan to start; when the condensation temperature is within the second temperature range, control two fans to start; when the condensation temperature is within the third temperature range, control three fans to start; when the condensation temperature is within the fourth temperature range, control four fans to start.

[0051] Among them, the first temperature range is [a, b], the second temperature range is (b, c], the third temperature range is (c, d], the fourth temperature range is (d, e], and a < b < c < d < e.

[0052] Specifically, the four temperature ranges are adjacent to each other in sequence. By dividing appropriate temperature ranges, the power of the fan can be matched with the condensation pressure. The greater the power of the fan, the larger the temperature range included in one temperature range, and the larger the adjustable range of the fan speed controller, the more intervals can be adjusted within one temperature range, and the more precise the control of the fan speed. If both the power of the fan and the adjustable range of the fan speed controller are large, then the temperature range included in one temperature range is large, and the number of intervals that can be adjusted is also large.

[0053] Furthermore, when the condensation temperature is within the first temperature range, if the condensation temperature is between [a, a1], the input voltage of the fan speed controller is the first voltage; if the condensation temperature is between (a1, a2], the input voltage of the fan speed controller is the second voltage; if the condensation temperature is between (a2, a3], the input voltage of the fan speed controller is the third voltage; if the condensation temperature is between (a3, a4], the input voltage of the fan speed controller is the fourth voltage; if the condensation temperature is between (a4, b], the input voltage of the fan speed controller is the fifth voltage.

[0054] When the condensation temperature is within the second temperature range, if the condensation temperature is between (b, b1], the input voltage of the fan speed controller is the first voltage; if the condensation temperature is between (b1, b2], the input voltage of the fan speed controller is the second voltage; if the condensation temperature is between (b2, b3], the input voltage of the fan speed controller is the third voltage; if the condensation temperature is between (b3, b4], the input voltage of the fan speed controller is the fourth voltage; if the condensation temperature is between (b4, c], the input voltage of the fan speed controller is the fifth voltage. Among them, a < a1 < a2 < a3 < a4 < b, b < b1 < b2 < b3 < b4 < c.

[0055] When the condensation temperature is in the third temperature range, if the condensation temperature is between (c, c1], the input voltage of the fan speed regulator is the first voltage; if the condensation temperature is between (c1, c2], the input voltage of the fan speed regulator is the second voltage; if the condensation temperature is between (c2, c3], the input voltage of the fan speed regulator is the third voltage; if the condensation temperature is between (c3, c4], the input voltage of the fan speed regulator is the fourth voltage; if the condensation temperature is between (c4, d], the input voltage of the fan speed regulator is the fifth voltage; where c < c1 < c2 < c3 < c4 < d.

[0056] When the condensation temperature is in the fourth temperature range, if the condensation temperature is between (d, d1], the input voltage of the fan speed regulator is the first voltage; if the condensation temperature is between (d1, d2], the input voltage of the fan speed regulator is the second voltage; if the condensation temperature is between (d2, d3], the input voltage of the fan speed regulator is the third voltage; if the condensation temperature is between (d3, d4], the input voltage of the fan speed regulator is the fourth voltage; if the condensation temperature is between (d4, e], the input voltage of the fan speed regulator is the fifth voltage; where d < d1 < d2 < d3 < d4 < e.

[0057] Specifically, referring to Figure 5 , each temperature range contains multiple small temperature ranges. For example, the small temperature ranges contained in the first temperature range are [a, a1], (a1, a2], (a2, a3], (a3, a4], (a4, b]. Each small temperature range corresponds to a different input voltage of the fan speed regulator, and the small temperature ranges in the same temperature range are also adjacent. By dividing the temperature range to control the number of fans turned on, hierarchical control can be achieved. By controlling the input voltage of the fan speed regulator in each temperature range, the total power of the fans that have been turned on can be controlled, so that the total power of the 4 fans has 21 adjustment ranges, and the total power of the fans that have been turned on can be adjusted between w1 - w21. Thus, the fan speed adjustment range is greatly increased, the air volume waste is reduced, the air volume required for various loads can be satisfied, the air volume waste is reduced, the overall machine power is lowered, and the energy efficiency of the unit is improved.

[0058] It should be noted that the embodiment of the present invention does not limit the number of small temperature ranges contained in each temperature range, which can be adaptively increased according to the adjustable range of the input voltage of the fan speed regulator. The larger the adjustable range of the input voltage of the fan speed regulator, the more the number of small temperature ranges contained in each temperature range, so as to more accurately control the total power of the fans.

[0059] Figure 6 is a schematic diagram of another data comparison table provided by the embodiment of the present invention, such asFigure 6 As shown, optionally, the first voltage is 6V, the second voltage is 7V, the third voltage is 8V, the fourth voltage is 9V, and the fifth voltage is 10V.

[0060] Specifically, the total range of the input voltage of the fan speed regulator is 0 - 10V. Since low air volume will affect the pressure fluctuation of the unit system, therefore, as Figure 6 shown, the minimum voltage of the input voltage of the fan speed regulator is set to 6V, that is, the first voltage is 6V, the second voltage is 7V, the third voltage is 8V, the fourth voltage is 9V, and the fifth voltage is 10V, corresponding to 5 adjustment intervals respectively, so as to stabilize the pressure of the air-cooled chiller and make it not easy to fluctuate.

[0061] In addition, in the Figure 6 data comparison table, the range of the condensation temperature is 31 - 50°C, corresponding to different temperature intervals and the number of fans turned on respectively. In the same temperature interval, each condensation temperature has a corresponding input voltage of the fan speed regulator and the total power of the turned-on fans. The unit of the input voltage of the fan speed regulator is V, and the unit of the total power of the fans is KW. The adjustable range of the total power of 4 fans is 1.4KW - 8KW, with a total of 29 adjustment intervals, further increasing the power adjustment interval. In addition, only one fan speed regulator needs to be added in the embodiment of the present invention, which can meet the precise control of the total power, with low cost and is conducive to large-scale application. Through the Figure 6 data comparison table, the total power of the fans can be precisely controlled at different condensation temperatures, so that the total power of the fans matches the condensation pressure, and the fan speed adjustment interval is greatly increased, reducing the waste of air volume, being able to meet the air volume requirements of various loads, thereby reducing the waste of air volume, reducing the overall power of the machine, and improving the energy efficiency of the unit.

[0062] Figure 7 is a schematic diagram of the relationship between the total power of the fans and the condensation pressure provided by the embodiment of the present invention. Figure 7 In it, the abscissa is the condensation pressure and the ordinate is the total power of the fans. As Figure 6 and Figure 7 shown, when the air-cooled chiller performs automatic adjustment, when it is detected that the condensation temperature is in the first temperature interval, 1 fan is set to turn on according to the data comparison table. After the fan is turned on, the input voltage of the fan speed regulator can be adjusted to 6 - 10V according to the condensation temperature, so as to adjust the speed of the fan and avoid waste of unnecessary air volume; when it is detected that the condensation temperature is in the second temperature interval, the third temperature interval, and the fourth temperature interval, the air-cooled chiller will set 2, 3, and 4 fans to turn on according to the data comparison table. After the fans are turned on, the input voltage of the fan speed regulator can be adjusted to 6 - 10V according to the condensation temperature, so as to adjust the speed of the fans, which can greatly reduce the power of the fans at different loads. Comparing Figure 1 、Figure 2 and Figure 7 As can be seen from the line chart in Figure 7 , the hierarchical control + governor control greatly increases the control range of the fan, enabling the fan to be more energy-efficient and reducing useless work under different loads of the unit.

[0063] An embodiment of the present invention provides a control method for an air-cooled chiller. By combining hierarchical control and one fan governor to control the condensing pressure of the unit, under hierarchical control, the fan governor is used to control the fan air volume to the saturation pressure corresponding to the condensing temperature, and a wide range of matching adjustments are made to the fan speed to reduce air volume waste, thereby reducing the overall power of the machine, improving energy efficiency, and eliminating useless work.

[0064] An embodiment of the present invention also provides an air-cooled chiller. Figure 8 As shown in the structural schematic diagram of the air-cooled chiller provided by the embodiment of the present invention, as Figure 8 shown, the air-cooled chiller includes n fans 110, one fan governor 120, and a control module 130.

[0065] The fan governor 120 is respectively connected to the n fans 110, and the control module 130 is respectively connected to the n fans 110 and the fan governor 120; the fan governor 120 is used to control the speed of the n fans 110 according to the input voltage of the fan governor 120.

[0066] The control module 130 is used to obtain the condensing temperature of the air-cooled chiller; the control module 130 is also used to control the activation of the i fans 110 when the condensing temperature is in the i-th temperature range; where n adjacent temperature ranges are provided in total, and i is any integer between 0 and n; the control module 130 is also used to control the magnitude of the input voltage of the fan governor 120 according to the condensing temperature in the temperature range where the condensing temperature is located, so as to control the total power of the i fans 110.

[0067] Among them, the fan 110 can be an AC fan. The fan governor 120 is respectively connected to the n fans 110, and the control module 130 is respectively connected to the n fans 110 and the fan governor 120. The fan governor 120 can control the speed of the n fans 110 according to its own input voltage. The control module 130 can respectively control the activation and deactivation of the n fans 110, and control the speed of the fans 110 by hierarchically controlling the input voltage of the fan governor 120, and perform matching adjustment on the speed of the fans 110 in real time according to the condensing temperature to reduce air volume waste, thereby reducing the overall power of the machine.

[0068] Specifically, when the condensing temperature is in the i-th temperature interval, the control module 130 controls the opening of i fans 110, and then the fan speed regulator 120 performs more precise speed regulation. Exemplarily, the number of fans 110 and the temperature interval are both 4. When the condensing temperature is in the second temperature interval, the opening of two fans 110 is controlled, and then the fan speed regulator 120 performs more precise speed regulation to avoid unnecessary waste of air volume; if the condensing temperature rises from the second temperature interval to the third temperature interval, the opening of three fans 110 is controlled, and then the fan speed regulator 120 performs more precise speed regulation to avoid unnecessary waste of air volume. By controlling the opening of the fans 110 in stages according to the condensing temperature, so that the number of fans 110 opened matches the condensing pressure, the waste of air volume and the increase in energy consumption caused by the excessive opening of the fans 110 can be avoided. The control module 130 can also pre-establish a data comparison table of condensing temperature, temperature range, input voltage of the fan speed regulator 120, and total power of the fan 110, and control the total power of the fan 110 by combining hierarchical control and the fan speed regulator 120. When the acquired condensing temperature is in the corresponding temperature range in the data comparison table, the number of fans 110 corresponding to the temperature range is turned on, and the input voltage of the fan speed regulator 120 is controlled to be the input voltage of the fan speed regulator 120 corresponding to the condensing temperature in the data comparison table, so that the acquired condensing temperature matches the total power of the fan 110. Since the control module 130 of the embodiment of the present invention controls the opening of the fan 110 in stages and controls the input voltage of the fan speed regulator 120 according to the condensing temperature, the speed adjustment range of the fan 110 is greatly increased, so that the air volume required by various loads can be met, and the pressure of the air-cooled chiller can be stabilized. This can avoid the problems of air volume waste and increased energy consumption caused by too many fans 110 being turned on, and can match the appropriate power under each condensing pressure, thereby greatly increasing the control range of the fan 110, so that the fan 110 can be more energy-efficient and reduce useless work under different loads of the unit.

[0069] In addition, the air-cooled chiller of the embodiment of the present invention includes but is not limited to the above-mentioned equipment. The air-cooled chiller of the embodiment of the present invention can adaptively set relevant functional modules according to the control method of the air-cooled chiller in any embodiment of the present invention to achieve the function and technical effect of the control method of the air-cooled chiller in any embodiment of the present invention.

[0070] An embodiment of the present invention provides an air-cooled chiller. The air-cooled chiller includes n fans and a fan speed governor. The fan speed governor is respectively connected to the n fans, and the fan speed governor is respectively connected to the n fans 110. The control module is respectively connected to the n fans and the fan speed governor. The fan speed governor is used to control the rotation speeds of the n fans according to the input voltage of the fan speed governor. The control module combines temperature hierarchical control and the fan speed governor to control the fan rotation speed. By obtaining the condensation temperature of the air-cooled chiller, when the condensation temperature is in the i-th temperature range, i fans are controlled to start, so as to achieve hierarchical control of fan start according to the condensation temperature, avoid waste of air volume and increase in energy consumption caused by excessive fan start. By controlling the magnitude of the input voltage of the fan speed governor according to the condensation temperature, the power of each fan is controlled to control the total power of the i fans, further increasing the fan rotation speed adjustment range and reducing waste of air volume. The present invention can meet the air volume requirements of various loads by increasing the fan rotation speed adjustment range, thereby reducing waste of air volume, reducing the overall machine power, and improving the energy efficiency of the unit.

[0071] An embodiment of the present invention also provides an air conditioner, and the air conditioner includes the air-cooled chiller according to any embodiment of the present invention.

[0072] The air conditioner in the embodiment of the present invention can use the air-cooled chiller according to any embodiment of the present invention for refrigeration, and can achieve the same functions and technical effects as the air-cooled chiller in the above embodiments.

[0073] Note that the above is only the preferred embodiment of the present invention and the applied technical principle. Those skilled in the art will understand that the present invention is not limited to the specific embodiments here. Various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A control method for an air-cooled chiller, characterized in that: The air-cooled chiller comprises n fans and a fan speed regulator, wherein the fan speed regulators are respectively connected to the n fans, and the control method comprises: Obtaining the condensing temperature of the air-cooled chiller; When the condensing temperature is in the i-th temperature interval, the i-th fans are controlled to be turned on; wherein there are n adjacent temperature intervals in total, and i is any integer between 1 and n; In the temperature range where the condensing temperature is located, the magnitude of the input voltage of the fan speed regulator is controlled according to the condensing temperature to control the total power of i fans.

2. The control method of the air-cooled chiller according to claim 1, characterized in that: The step of controlling the input voltage of the fan speed regulator according to the condensing temperature to control the total power of i fans includes: Establishing a data comparison table of the condensing temperature and the input voltage of the fan speed regulator; The input voltage of the fan speed regulator is adjusted according to the condensing temperature and the data comparison table to control the total power of i fans.

3. The control method of the air-cooled chiller according to claim 2, characterized in that: Establishing a data comparison table of the condensing temperature and the input voltage of the fan speed regulator, including: Determine the total power of i of the fans according to the input voltage of the fan speed regulator and the number i of fans turned on, and obtain a power comparison table; Setting the input voltage of the fan speed regulator corresponding to different condensing temperatures in different temperature ranges; The data comparison table is obtained by associating the input voltage of the fan speed regulator and the condensing temperature in the power comparison table.

4. The control method of the air-cooled chiller according to claim 1, characterized in that: n=4, when the condensing temperature is in the i-th temperature interval, controlling the opening of i fans includes: When the condensing temperature is in the first temperature interval, one of the fans is controlled to be turned on; when the condensing temperature is in the second temperature interval, two of the fans are controlled to be turned on; when the condensing temperature is in the third temperature interval, three of the fans are controlled to be turned on; when the condensing temperature is in the fourth temperature interval, four of the fans are controlled to be turned on; Among them, the first temperature interval is [a, b], the second temperature interval is (b, c], the third temperature interval is (c, d], and the fourth temperature interval is (d, e], a<b<c<d<e.

5. The control method of the air-cooled chiller according to claim 4, characterized in that: Controlling the input voltage of the fan speed regulator according to the condensing temperature includes: When the condensing temperature is in the first temperature interval, if the condensing temperature is between [a, a1], the input voltage of the fan speed regulator is the first voltage; if the condensing temperature is between (a1, a2], the input voltage of the fan speed regulator is the second voltage; if the condensing temperature is between (a2, a3], the input voltage of the fan speed regulator is the third voltage; if the condensing temperature is between (a3, a4], the input voltage of the fan speed regulator is the fourth voltage; if the condensing temperature is between (a4, b], the input voltage of the fan speed regulator is the fifth voltage; When the condensing temperature is within the second temperature interval, if the condensing temperature is between (b, b1], the input voltage of the fan speed regulator is the first voltage; if the condensing temperature is between (b1, b2], the input voltage of the fan speed regulator is the second voltage; if the condensing temperature is between (b2, b3], the input voltage of the fan speed regulator is the third voltage; if the condensing temperature is between (b3, b4], the input voltage of the fan speed regulator is the fourth voltage; if the condensing temperature is between (b4, c], the input voltage of the fan speed regulator is the fifth voltage; Among them, a <a1<a2<a3<a4<b,b<b1<b2<b 3<b4<c。 6. The control method of the air-cooled chiller according to claim 5, characterized in that: The input voltage of the fan speed regulator is controlled according to the condensing temperature, and further includes: When the condensing temperature is in the third temperature interval, if the condensing temperature is between (c, c1], the input voltage of the fan speed regulator is the first voltage; if the condensing temperature is between (c1, c2], the input voltage of the fan speed regulator is the second voltage; if the condensing temperature is between (c2, c3], the input voltage of the fan speed regulator is the third voltage; if the condensing temperature is between (c3, c4], the input voltage of the fan speed regulator is the fourth voltage; if the condensing temperature is between (c4, d], the input voltage of the fan speed regulator is the fifth voltage; wherein, c <c1<c2<c3<c4<d。 7. The control method of the air-cooled chiller according to claim 6, characterized in that: The input voltage of the fan speed regulator is controlled according to the condensing temperature, and further includes: When the condensing temperature is in the fourth temperature interval, if the condensing temperature is between (d1, d2], the input voltage of the fan speed regulator is the first voltage; if the condensing temperature is between (d2, d3], the input voltage of the fan speed regulator is the second voltage; if the condensing temperature is between (d3, d4], the input voltage of the fan speed regulator is the third voltage; if the condensing temperature is between (d4, e], the input voltage of the fan speed regulator is the fifth voltage; wherein, d <d1<d2<d3<d4<e。 8. The control method of the air-cooled chiller according to claim 7, characterized in that: The first voltage is 6V, the second voltage is 7V, the third voltage is 8V, the fourth voltage is 9V, and the fifth voltage is 10V.

9. An air-cooled chiller, characterized in that: The air-cooled chiller includes n fans, a fan speed regulator and a control module; The fan speed regulator is connected to the n fans respectively, and the control module is connected to the n fans and the fan speed regulator respectively; the fan speed regulator is used to control the speed of the n fans according to the input voltage of the fan speed regulator; The control module is used to obtain the condensing temperature of the air-cooled chiller; the control module is also used to control the opening of i fans when the condensing temperature is in the i-th temperature interval; wherein there are a total of n adjacent temperature intervals, and i is any integer between 0-n; the control module is also used to control the input voltage of the fan speed regulator according to the condensing temperature in the temperature interval where the condensing temperature is located, so as to control the total power of the i fans.

10. An air conditioner, comprising the air-cooled chiller according to claim 9.

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