Control method and device for chiller, and chiller

Abstract

The present application relates to the technical field of smart home appliances, and discloses a control method for a chiller. The control method comprises: after the chiller executes a preset quick start mode, obtaining the compressor exhaust pressure, compressor suction pressure and compressor oil level status of the chiller; adjusting the compressor operating frequency of the chiller according to the compressor exhaust pressure, the compressor suction pressure and the compressor oil level status. While adjusting the compressor operating frequency, the method also takes into account the impact of the change in the compressor operating frequency on the oil return performance of the compressor, and can make the adjustment of the compressor operating frequency more accurate, so that the chiller responds quickly to the start-up, thereby improving the start-up efficiency of the chiller. The present application also discloses a control device for a chiller and a chiller.

Description

Technical Field

[0001] The present application relates to the technical field of smart home appliances, for example, to a control method and device for a chiller, and a chiller. Background Art

[0002] Currently, conventional startup of chillers (such as variable frequency screw chillers) is slow and cannot respond to user needs.

[0003] In order to solve the problem of slow conventional startup of variable frequency screw chillers, the related art discloses a frequency control method for a variable frequency heat pump water heater compressor. The method comprises the following steps: detecting the outlet water temperature of a heat exchanger and the water tank temperature of a water tank; generating the outlet water set temperature of the heat exchanger according to the water tank temperature; and controlling the frequency of the variable frequency compressor according to the outlet water temperature of the heat exchanger and the outlet water set temperature.

[0004] In the process of implementing the embodiments of the present disclosure, it is found that the related art has at least the following problems: although the related art can control the frequency of the variable frequency compressor according to the outlet water temperature of the heat exchanger and the outlet water set temperature, the related art, however, adjusts the frequency of the compressor slowly when the outlet water temperature changes slowly, thereby affecting the startup efficiency of the variable frequency screw chiller.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0006] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical components or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

[0007] The embodiments of the present disclosure provide a control method and device for a chiller, and a chiller to improve the startup efficiency of the chiller.

[0008] In some embodiments, the control method includes: after the chiller executes a preset quick start mode, obtaining the compressor exhaust pressure, compressor suction pressure and compressor oil level status of the chiller; and adjusting the compressor operating frequency of the chiller according to the compressor exhaust pressure, the compressor suction pressure and the compressor oil level status.

[0009] Optionally, adjusting the compressor operating frequency of the chiller according to the compressor exhaust pressure, the compressor suction pressure and the compressor oil level status includes: determining a first operating frequency according to the compressor exhaust pressure and the compressor suction pressure; determining a second operating frequency according to the compressor oil level status; when the second operating frequency is equal to the first operating frequency, adjusting the current compressor operating frequency of the chiller to the second operating frequency and maintaining the second operating frequency; when the second operating frequency is not equal to the first operating frequency, adjusting the current compressor operating frequency of the chiller to the second operating frequency, and giving the second operating frequency an up-frequency adjustment.

[0010] Optionally, the first operating frequency is obtained in the following manner: Calculate ΔP=N p -N x , obtain the pressure difference between the compressor exhaust pressure and the compressor suction pressure; wherein ΔP is the pressure difference between the compressor exhaust pressure and the compressor suction pressure, N p is the compressor exhaust pressure, N x is the suction pressure of the compressor; determining a first frequency compensation rate according to the pressure difference; and based on the current operating frequency of the compressor of the chiller, controlling the compressor of the chiller to increase the frequency at the first frequency compensation rate to obtain the first operating frequency.

[0011] Optionally, determining the first frequency compensation rate according to the pressure difference comprises: when ΔP≥P 1 In the case of, determining the first frequency compensation rate is the first rate v 1 ; In P 2 ≤ΔP<P 1 In the case of, determining the first frequency compensation rate is the second rate v 2 ; In P 3 ≤ΔP<P 2 In the case of 3 ; In ΔP<P 3 In the case of, determining the first frequency compensation rate to be the fourth rate v 4 ; Among them, P 1 is the first pressure threshold, P 2 is the second pressure threshold; P 3 is the third pressure threshold, v 1 <v 2 <v 3 <v 4 .

[0012] Optionally, determine the temperature difference ΔT between the outlet water temperature and the inlet water temperature of the chiller 1, including: starting the chiller; when the running time of the chiller is greater than or equal to the preset time t 0 In the case of periodic determination of the temperature difference △T between the chiller's outlet water temperature and inlet water temperature 1 .

[0013] Optionally, the second operating frequency is obtained in the following manner: when the oil level of the compressor is less than a preset oil level, the second operating frequency F is calculated. 2 =F 1 +A; where F 1 is the first operating frequency, A is the frequency adjustment parameter, and A>0; when the oil level of the compressor is greater than or equal to the preset oil level, and the first operating frequency reaches the maximum operating frequency of the compressor, the second operating frequency F is calculated 2 =F 1 .

[0014] Optionally, after adjusting the operating frequency of the compressor of the chiller, the method further includes: obtaining the outlet water temperature of the chiller; calculating ΔT=T c -T 0 , obtain the temperature difference between the outlet water temperature and the preset target temperature; wherein ΔT is the temperature difference between the outlet water temperature and the preset target temperature, T c is the outlet water temperature, T 0 is the preset target temperature; 1 ≤ΔT≤T 2 In the case of, determining the second frequency compensation rate according to the temperature difference; wherein, T 1 is the first temperature threshold, T 2 is a second temperature threshold; based on the current operating frequency of the compressor of the chiller, the compressor of the chiller is controlled to perform frequency reduction adjustment at the second frequency compensation rate.

[0015] Optionally, determining the second frequency compensation rate according to the temperature difference comprises: 3 ≤ΔT≤T 2 In the case of 1 ; in T 4 ≤ΔT<T 3 In the case of 2 ; in T 5 ≤ΔT<T 4 In the case of 3 ; in T 1 <ΔT<T 5 In the case of 4 ; at ΔT = T1 In the case of 5 ; Among them, T 3 is the third temperature threshold, T 4 is the fourth temperature threshold; T 5 is the fifth temperature threshold; v 5 <v 1 <v 2 <v 3 <v 4 .

[0016] Optionally, the chiller executes a preset quick start mode including: adjusting the operating frequency of the compressor of the chiller to a preset operating frequency; and controlling the compressor of the chiller to operate for a preset time at the preset operating frequency.

[0017] Optionally, before the chiller executes the preset quick start mode, the method further includes: obtaining the outlet water temperature of the chiller; calculating ΔT=T c -T 0 , obtain the temperature difference between the outlet water temperature and the preset target temperature; when ΔT>T 6 In the case of, controlling the chiller to execute a preset quick start mode; wherein, T 6 is the sixth temperature threshold.

[0018] Optionally, the control method further comprises: when ΔT≤T 6 Under the circumstances, control the chiller to execute the preset operation mode.

[0019] Optionally, the chiller executes a preset operation mode including: controlling the operating frequency of the compressor of the chiller to increase the frequency at a third frequency compensation rate.

[0020] In some embodiments, the device includes a processor and a memory storing program instructions, and the processor is configured to execute the control method for the chiller as described above when running the program instructions.

[0021] In some embodiments, the chiller includes: a chiller body; a compressor, which is arranged on the chiller body; and a control device for the chiller as described above, which is installed on the chiller body.

[0022] The control method, device, and chiller provided by the embodiments of the present disclosure can achieve the following technical effects:

[0023] In the disclosed embodiment, the water chiller executes a preset quick start mode, that is, the water chiller is preheated for startup, so that the compressor establishes a suction and exhaust pressure difference, which is beneficial to the oil return of the compressor. After the water chiller executes the preset quick start mode, by monitoring the compressor exhaust pressure, the compressor suction pressure and the compressor oil level status, while adjusting the compressor operating frequency, the influence of the compressor operating frequency change on the compressor oil return performance is also considered, which can make the adjustment of the compressor operating frequency more accurate, so that the water chiller responds to startup quickly, thereby improving the startup efficiency of the water chiller.

[0024] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] One or more embodiments are exemplarily described by corresponding drawings, which do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements, and the drawings do not constitute a scale limitation, and wherein:

[0026] Figure 1 is a schematic structural diagram of a chiller provided by an embodiment of the present disclosure;

[0027] Figure 2 is a schematic diagram of a control method for a chiller provided by an embodiment of the present disclosure;

[0028] Figure 3 is a schematic diagram of another control method for a chiller provided by an embodiment of the present disclosure;

[0029] Figure 4 is a schematic diagram of another control method for a chiller provided by an embodiment of the present disclosure;

[0030] Figure 5 is a schematic diagram of another control method for a chiller provided by an embodiment of the present disclosure;

[0031] Figure 6 is a schematic diagram of a control device for a chiller provided by an embodiment of the present disclosure;

[0032] Figure 7 It is a schematic diagram of a chiller product provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0033] In order to be able to understand the features and technical contents of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0034] The terms "first", "second", etc. in the specification and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0035] Unless otherwise stated, the term "plurality" means two or more.

[0036] The term "and / or" is a description of the association relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or, A and B.

[0037] The term "correspondence" may refer to an association relationship or a binding relationship. The correspondence between A and B means that there is an association relationship or a binding relationship between A and B.

[0038] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other.

[0039] At present, the conventional startup of the chiller (such as the variable frequency screw chiller) is slow and cannot respond to user needs. In order to solve the problem of the slow conventional startup of the variable frequency screw chiller, the related art discloses a frequency control method for the compressor of the variable frequency heat pump water heater. The steps of the method are as follows: detecting the outlet water temperature of the heat exchanger and the water tank temperature of the water tank; generating the outlet water set temperature of the heat exchanger according to the water tank temperature; and controlling the frequency of the variable frequency compressor according to the outlet water temperature of the heat exchanger and the outlet water set temperature. Although the related art can control the frequency of the variable frequency compressor according to the outlet water temperature of the heat exchanger and the outlet water set temperature. However, when the outlet water temperature changes slowly, the related art adjusts the frequency of the compressor slowly, thereby affecting the startup efficiency of the variable frequency screw chiller.

[0040] In the disclosed embodiment, while the operating frequency of the compressor is adjusted on the basis of the chiller executing a preset quick start mode, the impact of changes in the operating frequency of the compressor on the oil return performance of the compressor is also taken into account, which can make the adjustment of the operating frequency of the compressor more accurate, thereby enabling the chiller to respond quickly to startup, thereby improving the startup efficiency of the chiller.

[0041] The present disclosure provides a chiller 1 such as Figure 1 As shown, the chiller 1 includes: a chiller body 10, a compressor 101, a condenser 102, a throttling device 103, an evaporator 104, a frequency converter 105 and an electronic control device (not shown in the figure). Among them, the compressor 101, the condenser 102, the throttling device 103 and the evaporator 104 form a refrigerant circuit through a pipeline. The compressor 101 is arranged on the chiller body 10, and has a compressor exhaust port 1011 and a compressor intake port 1012. The frequency converter 105 is arranged corresponding to the compressor 101 and is electrically connected to the compressor 101, and is used to control the motor speed of the compressor 101, thereby controlling the operating frequency of the compressor 101. By controlling the compressor 101 through the frequency converter 105, the starting current is small and there is no impact on the power grid. At the same time, the frequency converter 105 controls the operating frequency of the compressor 101, which can play a good energy regulation role and achieve energy saving effect. The electronic control device includes a processor. The processor is used to adjust the frequency conversion rate of the frequency converter 105 , thereby adjusting the operating frequency of the compressor 101 . The processor is also used to control other electronic control components to realize various functions of the chiller 1 .

[0042] Optionally, the chiller 1 further comprises a first pressure sensor and a second pressure sensor. The first pressure sensor is arranged at the compressor exhaust port 1011 for detecting the compressor exhaust port pressure. The second pressure sensor is arranged at the compressor intake port 1012 for detecting the compressor intake port pressure.

[0043] Optionally, the chiller 1 further comprises a temperature sensor. The temperature sensor is arranged on the chilled water outlet pipeline of the chiller and is used to detect the outlet water temperature of the chiller.

[0044] Optionally, the chiller 1 further comprises an oil level switch. The oil level switch is used to detect the oil level status of the compressor and transmit the compressor oil level status information to the processor.

[0045] Combination Figure 1 The chiller shown in the figure, the present disclosure provides a control method for the chiller. Figure 2 As shown, the method includes:

[0046] S201, after the chiller executes a preset quick start mode, the processor obtains the compressor exhaust pressure, compressor suction pressure and compressor oil level status of the chiller.

[0047] S202, the processor adjusts the compressor operating frequency of the chiller according to the compressor exhaust pressure, the compressor suction pressure and the compressor oil level status.

[0048] In the above embodiment, the water chiller executes the preset quick start mode, that is, the water chiller is preheated for startup, so that the compressor establishes a suction and exhaust pressure difference, which is beneficial to the oil return of the compressor. After the water chiller executes the preset quick start mode, by monitoring the compressor exhaust pressure, the compressor suction pressure and the compressor oil level status, while adjusting the compressor operating frequency, the influence of the compressor operating frequency change on the compressor oil return performance is also considered, which can make the adjustment of the compressor operating frequency more accurate, so that the water chiller responds to startup quickly, thereby improving the startup efficiency of the water chiller.

[0049] Optionally, the processor adjusts the compressor operating frequency of the chiller according to the compressor exhaust pressure, the compressor suction pressure and the compressor oil level status, including: the processor determines a first operating frequency according to the compressor exhaust pressure and the compressor suction pressure. The processor determines a second operating frequency according to the compressor oil level status. When the second operating frequency is equal to the first operating frequency, the processor adjusts the current compressor operating frequency of the chiller to the second operating frequency and maintains the second operating frequency. When the second operating frequency is not equal to the first operating frequency, the processor adjusts the current compressor operating frequency of the chiller to the second operating frequency, and performs frequency increase adjustment on the second operating frequency.

[0050] In the above embodiment, the first operating frequency can be accurately obtained by the compressor exhaust pressure and the compressor suction pressure. The second operating frequency can be accurately obtained by the compressor oil level state. When the second operating frequency is equal to the first operating frequency, it indicates that the second operating frequency has reached the maximum operating frequency. Then, the current compressor operating frequency of the chiller is adjusted to the second operating frequency, and the chiller startup is completed. When the second operating frequency is equal to the first operating frequency, it indicates that the second operating frequency has not reached the maximum operating frequency. Then, based on the second operating frequency, the compressor operating frequency is continued to be increased to complete the startup of the chiller. In this way, the startup of the chiller can be reasonably and timely achieved.

[0051] Optionally, the processor adjusts the current compressor operating frequency of the chiller to a second operating frequency, and gives the second operating frequency an up-frequency adjustment, including: after the processor adjusts the current compressor operating frequency of the chiller to the second operating frequency, based on the current compressor operating frequency of the chiller, the processor adjusts the compressor operating frequency of the chiller according to the compressor exhaust pressure, the compressor suction pressure and the compressor oil level status.

[0052] In the above embodiment, on the basis that the compressor operating frequency is running at the second operating frequency, the processor adjusts the compressor operating frequency again according to the compressor exhaust pressure, the compressor suction pressure and the compressor oil level state. In this way, the adjustment of the compressor operating frequency can be more accurate and reasonable.

[0053] Optionally, the processor obtains the first operating frequency in the following manner: the processor calculates ΔP=N p -N x , and obtain the pressure difference between the compressor exhaust pressure and the compressor suction pressure. Among them, ΔP is the pressure difference between the compressor exhaust pressure and the compressor suction pressure, N p is the compressor exhaust pressure, N x is the suction pressure of the compressor. The processor determines a first frequency compensation rate according to the pressure difference. Based on the current operating frequency of the compressor of the chiller, the processor controls the compressor of the chiller to increase the frequency at the first frequency compensation rate to obtain a first operating frequency.

[0054] In the above embodiment, the change of the compressor operating frequency can be accurately obtained through the pressure difference between the compressor exhaust pressure and the compressor suction pressure. Therefore, according to the pressure difference between the compressor exhaust pressure and the compressor suction pressure, the compressor operating frequency is adjusted to increase the frequency at the first frequency compensation rate, with high adjustment accuracy and strong real-time performance.

[0055] Optionally, the processor determines the first frequency compensation rate according to the pressure difference, including: when ΔP≥P 1 In the case of, the processor determines the first frequency compensation rate as the first rate v 1 In P 2 ≤ΔP<P 1 In the case of, the processor determines the first frequency compensation rate to be the second rate v 2 In P 3 ≤ΔP<P 2 In the case of, the processor determines the first frequency compensation rate to be the third rate v 3 . In ΔP<P 3 In the case of, the processor determines the first frequency compensation rate to be the fourth rate v 4 .

[0056] Among them, P 1 is the first pressure threshold, P 2 is the second pressure threshold; P 3 is the third pressure threshold. Optionally, 0.3Mpa (megapascal) ≤ P 1 ≤0.4Mpa. More specifically, P 1 Set to 0.3Mpa, 0.35Mpa or 0.4Mpa. Optionally, 0.2Mpa ≤ P 2<0.3Mpa. More specifically, P 2 Set to 0.2Mpa, 0.25Mpa or 0.29Mpa. Optionally, 0.1Mpa ≤ P 3 <0.2Mpa. More specifically, P 3 Set to 0.1Mpa, 0.15Mpa or 0.19Mpa.

[0057] Optionally, 0.1 Hz / s (Hertz per second) < v 1 ≤0.35Hz / s. More specifically, v 1 Set to 0.2Hz / s, 0.25Hz / s or 0.3Hz / s. Optionally, 0.3Hz / s<v 2 ≤0.65Hz / s. More specifically, v 2 Set to 0.45Hz / s, 0.5Hz / s or 0.55Hz / s. Optionally, 0.65Hz / s<v 3 ≤0.85Hz / s. More specifically, v 3 Set to 0.7Hz / s, 0.75Hz / s or 0.8Hz / s. Optionally, 0.85Hz / s<v 4 ≤1.5Hz / s. More specifically, v 4 Settings: 0.95Hz / s, 1Hz / s or 1.5Hz / s.

[0058] In the above embodiment, when ΔP is large, it indicates that the pressure difference between the compressor exhaust pressure and the compressor suction pressure is large, and the compressor oil return performance is good at this time. Then the compressor operating frequency is controlled to increase the frequency at a lower rate, so as to avoid the oil leakage of the compressor, which is beneficial to the stable operation of the chiller. When ΔP is small, it indicates that the pressure difference between the compressor exhaust pressure and the compressor suction pressure is small, and the compressor oil return performance is poor at this time. Then the compressor operating frequency is controlled to increase the frequency at a higher rate, so as to improve the oil return effect of the unit, which is beneficial to the stable operation of the chiller. Therefore, v 5 <v 1 <v 2 <v 3 <v 4 , which can make the adjustment of the compressor operating frequency more accurate, thereby avoiding oil leakage in the compressor caused by over-adjustment, and is beneficial to the stable operation of the chiller.

[0059] Optionally, the processor obtains the second operating frequency in the following manner: when the oil level of the compressor is less than a preset oil level, the processor calculates the second operating frequency F 2 =F 1 +A. Among them, F 1is the first operating frequency, A is the frequency adjustment parameter, and A>0. When the oil level of the compressor is greater than or equal to the preset oil level and the first operating frequency reaches the maximum operating frequency of the compressor, the processor calculates the second operating frequency F 2 =F 1 .

[0060] Optionally, 1.5 Hz ≤ A ≤ 2.5 Hz. More specifically, A is set to 1.5 Hz, 2 Hz or 2.5 Hz. A is set to this frequency interval to adjust the first operating frequency.

[0061] Optionally, the preset oil level is set to [(3 / 5)H, (7 / 10)H]. Wherein, H is the maximum height inside the compressor. More specifically, the preset oil level is set to (3 / 5)H, (2 / 3)H or (7 / 10)H. The preset oil level is set to this interval to avoid the compressor being in an oil shortage state due to the compressor oil level being too low.

[0062] In the above embodiment, when the compressor oil level is less than the preset oil level, it indicates that the compressor operating frequency is lower than the maximum operating frequency, and it is necessary to increase A on the basis of the first operating frequency to increase the compressor operating frequency. When the compressor oil level is greater than or equal to the preset oil level, and the first operating frequency reaches the maximum operating frequency of the compressor, it indicates that the compressor oil level is high, and the compressor operating frequency is the maximum operating frequency, and it is determined that the chiller is started. Therefore, there is no need to continue to increase the compressor operating frequency, so that the compressor continues to operate at the first operating frequency.

[0063] like Figure 3 As shown, the embodiment of the present disclosure provides another control method for a chiller. The method includes:

[0064] S301, after the chiller executes a preset quick start mode, the processor obtains the compressor exhaust pressure, compressor suction pressure and compressor oil level status of the chiller.

[0065] S302, the processor adjusts the compressor operating frequency of the chiller according to the compressor exhaust pressure, the compressor suction pressure and the compressor oil level status.

[0066] S303: The processor obtains the outlet water temperature of the chiller.

[0067] S304, the processor calculates ΔT=T c -T 0 , obtain the temperature difference between the outlet water temperature and the preset target temperature.

[0068] Where ΔT is the temperature difference between the outlet water temperature and the preset target temperature, T c is the outlet water temperature, T 0is the preset target temperature. Optionally, 5℃≤T 0 ≤15°C. More specifically, T 0 Set to 5°C, 7°C, 9°C, 11°C, 13°C or 15°C. 0 Setting it to this temperature range can meet the cooling demand of the chiller for the outlet water temperature.

[0069] S305, in T 1 ≤ΔT≤T 2 In this case, the processor determines a second frequency compensation rate based on the temperature difference.

[0070] Among them, T 1 is the first temperature threshold, T 2 is the second temperature threshold. Optionally, 0°C ≤ T 1 More specifically, T 1 Set to 0℃, 0.2℃ or 0.4℃. Optionally, 3℃<T 2 ≤5°C. More specifically, T 2 Set to 3.5°C, 4°C or 4.5°C. 1 , T 2 Set within the above temperature range to determine the load on the compressor.

[0071] S306: Based on the current operating frequency of the compressor of the chiller, the processor controls the compressor of the chiller to reduce the frequency at a second frequency compensation rate.

[0072] In the above embodiment, whether the compressor needs to reduce the load is determined by the temperature range of the temperature difference. 1 ≤ΔT≤T 2 In the case of , it indicates that the outlet water temperature is approaching the preset target temperature, and the compressor does not need to continue to operate at the highest operating frequency, that is, the compressor has a need to reduce the load. When the compressor has a need to reduce the load, the compressor operating frequency is adjusted according to the temperature difference, which can accurately match the compressor operating frequency with the required frequency, thereby matching the outlet water temperature with the preset target temperature. While meeting the cooling effect of the chiller, it saves energy and avoids waste of resources.

[0073] Optionally, the processor determines the second frequency compensation rate according to the temperature difference, including: 3 ≤ΔT≤T 2 In the case of, the processor determines the second frequency compensation rate to be the first rate v 1 In T 4 ≤ΔT<T 3 In the case of, the processor determines the second frequency compensation rate as the second rate v 2 In T 5 ≤ΔT<T4 In the case of, the processor determines the second frequency compensation rate to be the third rate v 3 In T 1 <ΔT<T 5 In the case of, the processor determines the second frequency compensation rate to be the fourth rate v 4 . When ΔT = T 1 In the case of 5 .

[0074] Among them, T 3 is the third temperature threshold, T 4 is the fourth temperature threshold; T 5 is the fifth temperature threshold. Optionally, 2.5°C (degrees Celsius) ≤ T 3 More specifically, T 3 Set to 2.5℃, 3℃ or 3.4℃. Optionally, 1.5℃≤T 4 More specifically, T 4 Set to 1.5℃, 2℃ or 2.4℃. Optionally, 0.5℃≤T 5 More specifically, T 5 Set to 0.5°C, 1°C or 1.4°C.

[0075] Optionally, 0Hz / s≤v 5 ≤0.1Hz / s. More specifically, v 5 Set to 0Hz / s, 0.05Hz / s or 0.1Hz / s. 1 When set to 0℃, v 5 Set to 0Hz / s. In this way, when the outlet water temperature is equal to the preset target temperature, the compressor is controlled to continue running at the current operating frequency.

[0076] In the above embodiment, when ΔT is large, it indicates that the outlet water temperature is high, and the compressor operating frequency is reduced at a lower rate to meet the cooling demand of the chiller. When ΔT is small, it indicates that the outlet water temperature is close to or equal to the preset target temperature, and the compressor operating frequency is reduced at a higher rate to meet the cooling demand of the chiller. Therefore, v 5 <v 1 <v 2 <v 3 <v 4 , while making the compressor operating frequency meet the cooling needs of the chiller, it can also save energy.

[0077] Optionally, the chiller executes the preset quick start mode including: the processor adjusts the operating frequency of the compressor of the chiller to a preset operating frequency. The processor controls the compressor of the chiller to operate at the preset operating frequency for a preset time.

[0078] Optionally, the preset operating frequency is set to [20Hz (Hertz), 30sHz]. More specifically, the preset operating frequency is set to 20Hz, 25Hz or 30Hz. It should be noted that the preset operating frequency should not be set too large or too small. If the preset operating frequency is set too large, the compressor may discharge more oil and absorb less oil, resulting in oil shortage in the compressor, thereby causing the compressor to malfunction. If the preset operating frequency is set too small, the pressure difference between the compressor exhaust pressure and the compressor suction pressure is small, which will cause abnormal oil return of the compressor. Therefore, setting the preset operating frequency to the above frequency range is conducive to the smooth start-up of the compressor.

[0079] Optionally, the preset time length is set to [25s (seconds), 130s]. More specifically, the preset time length is set to 30s, 50s, 70s, 90s, 110s or 130s. It should be noted that the preset time length should not be set too long or too short. If the preset time length is set too short, the compressor may not be able to absorb oil in time, resulting in oil shortage in the compressor, thereby causing the compressor to malfunction. If the preset time length is set too long, the pressure difference between the compressor exhaust pressure and the compressor suction pressure is small, which will cause abnormal oil return of the compressor. Therefore, setting the preset time length to the above time length range is conducive to the smooth start-up of the compressor.

[0080] In the above embodiment, the preset quick start mode is executed by the chiller to increase the frequency of the compressor to a preset operating frequency, and the compressor is operated at the preset operating frequency for a preset time. This can quickly establish a pressure difference between the compressor's intake and exhaust, which is beneficial to the oil return of the compressor.

[0081] like Figure 4 As shown, the embodiment of the present disclosure provides another control method for a chiller. The method includes:

[0082] S401, the processor obtains the outlet water temperature of the chiller.

[0083] S402, the processor calculates ΔT=T c -T 0 , obtain the temperature difference between the outlet water temperature and the preset target temperature.

[0084] S403, when ΔT>T 6 In this case, the processor controls the chiller to execute a preset fast start mode.

[0085] Among them, T 6is the sixth temperature threshold. Optionally, 5°C ≤ T 6 ≤9°C. More specifically, T 6 Set to 5°C, 7°C or 9°C. 6 Set this temperature range to determine the temperature difference between the outlet water temperature and the preset target temperature.

[0086] S404, the processor obtains the compressor exhaust pressure, compressor suction pressure and compressor oil level status of the chiller.

[0087] S405, the processor adjusts the compressor operating frequency of the chiller according to the compressor exhaust pressure, the compressor suction pressure and the compressor oil level status.

[0088] In the above embodiment, when ΔT>T 6 In the case of , it indicates that the temperature difference between the outlet water temperature and the preset target temperature is large, that is, the outlet water temperature is high. By controlling the chiller to execute the preset start-up mode, the rate at which the outlet water temperature of the chiller decreases is increased, thereby improving the startup efficiency of the chiller.

[0089] like Figure 5 As shown, the embodiment of the present disclosure provides another control method for a chiller. The method includes:

[0090] S501: The processor obtains the outlet water temperature of the chiller.

[0091] S502, the processor calculates ΔT=T c -T 0 , obtain the temperature difference between the outlet water temperature and the preset target temperature.

[0092] S503, when ΔT>T 6 In this case, the processor controls the chiller to execute a preset fast start mode.

[0093] S504, the processor obtains the compressor exhaust pressure, compressor suction pressure and compressor oil level status of the chiller.

[0094] S505, the processor adjusts the compressor operating frequency of the chiller according to the compressor exhaust pressure, the compressor suction pressure and the compressor oil level status.

[0095] S506, when ΔT≤T 6 In this case, the processor controls the chiller to execute a preset operation mode.

[0096] In the above embodiment, when ΔT≤T 6 In the case of , it indicates that the outlet water temperature is close to the preset target temperature, and the chiller is controlled to execute the preset operation mode. To meet the cooling demand of the chiller, reduce or maintain the outlet water temperature of the chiller.

[0097] Optionally, the chiller executes a preset operation mode including: the processor controls the compressor operating frequency of the chiller to increase the frequency at a third frequency compensation rate.

[0098] Optionally, the third frequency compensation rate is set to [0.1 Hz / s, 0.2 Hz / s]. More specifically, the third frequency compensation rate is set to 0.1 Hz / s, 0.15 Hz / s or 0.2 Hz / s. The third frequency compensation rate is set in this interval to maintain the cooling effect of the chiller while preventing the compressor from running out of oil due to excessive operating frequency.

[0099] Combination Figure 6 , the embodiment of the present disclosure provides a control device 200 for a chiller, including a processor (processor) 600 and a memory (memory) 601. Optionally, the control device 200 for a chiller may also include a communication interface (Communication Interface) 602 and a bus 603. Among them, the processor 600, the communication interface 602, and the memory 601 can communicate with each other through the bus 603. The communication interface 602 can be used for information transmission. The processor 600 can call the logic instructions in the memory 601 to execute the control method for the chiller of the above embodiment.

[0100] In addition, the logic instructions in the memory 601 described above can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product.

[0101] The memory 601, as a storage medium, can be used to store software programs, computer executable programs, such as program instructions / modules corresponding to the method in the embodiment of the present disclosure. The processor 600 executes the functional application and data processing by running the program instructions / modules stored in the memory 601, that is, implements the control method for the chiller in the above embodiment.

[0102] The memory 601 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required for at least one function; the data storage area may store data created according to the use of the terminal device, etc. In addition, the memory 601 may include a high-speed random access memory and may also include a non-volatile memory.

[0103] Combination Figure 7As shown, an embodiment of the present disclosure provides a chiller 1. The chiller 1 includes: a chiller body 10, a compressor and a control device 200 for the chiller as described above. The installation relationship described here is not limited to placement inside the chiller 1, but also includes installation connections with other components of the chiller 1, including but not limited to physical connections, electrical connections or signal transmission connections. It can be understood by those skilled in the art that the control device 200 for the chiller can be adapted to a feasible chiller body 10, thereby realizing other feasible embodiments. Among them, the compressor is arranged in the chiller body 10.

[0104] An embodiment of the present disclosure provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are configured to execute the above-mentioned control method for a chiller.

[0105] An embodiment of the present disclosure provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are configured to execute the above-mentioned control method for a chiller.

[0106] The computer-readable storage medium mentioned above may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0107] The technical solution of the embodiment of the present disclosure can be embodied in the form of a software product, which is stored in a storage medium and includes one or more instructions for enabling a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in the embodiment of the present disclosure. The aforementioned storage medium may be a non-transient storage medium, including: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and other media that can store program codes, or a transient storage medium.

[0108] The above description and the accompanying drawings sufficiently illustrate the embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, process, and other changes. The embodiments represent only possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Portions and features of some embodiments may be included in or replace portions and features of other embodiments. Moreover, the terms used in this application are only used to describe the embodiments and are not used to limit the claims. As used in the description of the embodiments and the claims, the singular forms "a" and "an" shall be construed as "a", "an" and "an" unless the context clearly indicates otherwise.

[0109] (a), "an" and "the" are intended to include plural forms as well. Similarly, the term "and / or" as used in this application is intended to include any and all possible combinations of one or more of the associated listed items. In addition, when used in this application, the term "including"

[0110] "comprise" and its variations "comprises" and / or comprising refer to the presence of stated features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups thereof. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method or device including the elements. In this article, each embodiment may focus on the differences from other embodiments, and the same and similar parts between the various embodiments may refer to each other. For the methods, products, etc. disclosed in the embodiments, if they correspond to the method part disclosed in the embodiments, then the relevant parts can refer to the description of the method part.

[0111] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software may depend on the specific application and design constraints of the technical solution. The technicians may use different methods for each specific application to implement the described functions, but such implementations should not be considered to exceed the scope of the embodiments of the present disclosure. The technicians may clearly understand that, for the convenience and simplicity of description, the specific working processes of the systems, devices and units described above may refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here.

[0112] In the embodiments disclosed herein, the disclosed methods and products (including but not limited to devices, equipment, etc.) can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units can be only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between each other shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms. The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to implement this embodiment. In addition, each functional unit in the embodiment of the present disclosure may be integrated in a processing unit, or each unit may exist physically alone, or two or more units may be integrated in one unit.

[0113] The flowchart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to the embodiment of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. In the description corresponding to the flowchart and the block diagram in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in a different order from the order disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified functions or actions, or may be implemented by a combination of dedicated hardware and computer instructions.

Claims

1. A control method for a chiller, It is characterized in that include: After the chiller executes a preset quick start mode, obtaining a compressor exhaust pressure, a compressor suction pressure and a compressor oil level status of the chiller; adjusting the compressor operating frequency of the chiller according to the compressor exhaust pressure, the compressor suction pressure and the compressor oil level state; According to the compressor exhaust pressure, the compressor suction pressure and the compressor oil level state, adjusting the compressor operating frequency of the chiller comprises: Determining a first operating frequency according to the compressor exhaust pressure and the compressor suction pressure; determining a second operating frequency according to the oil level state of the compressor; When the second operating frequency is equal to the first operating frequency, adjusting the current compressor operating frequency of the chiller to the second operating frequency, and maintaining the second operating frequency; When the second operating frequency is not equal to the first operating frequency, the current compressor operating frequency of the chiller is adjusted to the second operating frequency, and the second operating frequency is increased.

2. The control method according to claim 1, It is characterized in that The first operating frequency is obtained as follows: Calculate ΔP = N p -N x , obtain the pressure difference between the compressor exhaust pressure and the compressor suction pressure; wherein ΔP is the pressure difference between the compressor exhaust pressure and the compressor suction pressure, N p is the compressor exhaust pressure, N x is the compressor suction pressure; determining a first frequency compensation rate based on the pressure difference; Based on the current operating frequency of the compressor of the chiller, the compressor of the chiller is controlled to perform frequency increase regulation at the first frequency compensation rate to obtain the first operating frequency.

3. The control method according to claim 2, It is characterized in that The determining a first frequency compensation rate according to the pressure difference comprises: In ΔP ≥ P 1 In the case of, determining the first frequency compensation rate is the first rate v 1 ; In P 2 ≤ΔP<P 1 In the case of, determining the first frequency compensation rate is the second rate v 2 ; In P 3 ≤ΔP<P 2 In the case of 3 ; When ΔP<P 3 In the case of, determining the first frequency compensation rate to be the fourth rate v 4 ; Among them, P 1 is the first pressure threshold, P 2 is the second pressure threshold; P 3 is the third pressure threshold, v 1 <v 2 <v 3 <v 4 .

4. The control method according to claim 1, It is characterized in that The second operating frequency is obtained as follows: When the oil level of the compressor is less than the preset oil level, the second operating frequency F is calculated. 2 =F 1 +A; where F 1 is the first operating frequency, A is the frequency adjustment parameter, and A>0; When the oil level of the compressor is greater than or equal to the preset oil level and the first operating frequency reaches the maximum operating frequency of the compressor, the second operating frequency F is calculated. 2 =F 1 .

5. The control method according to any one of claims 1 to 4, It is characterized in that After adjusting the operating frequency of the compressor of the chiller, the method further comprises: Obtaining the outlet water temperature of the chiller; Calculate ΔT = T c -T 0 , obtain the temperature difference between the outlet water temperature and the preset target temperature; wherein ΔT is the temperature difference between the outlet water temperature and the preset target temperature, T c is the outlet water temperature, T 0 is the preset target temperature; In T 1 ≤ΔT≤T 2 In the case of, determining the second frequency compensation rate according to the temperature difference; wherein, T 1 is the first temperature threshold, T 2 is the second temperature threshold; Based on the current operating frequency of the compressor of the chiller, the compressor of the chiller is controlled to perform frequency reduction regulation at the second frequency compensation rate.

6. The control method according to claim 5, It is characterized in that The determining a second frequency compensation rate according to the temperature difference comprises: In T 3 ≤ΔT≤T 2 In the case of, determining the second frequency compensation rate to be the first rate v 1 ; In T 4 ≤ΔT<T 3 In the case of 2 ; In T 5 ≤ΔT<T 4 In the case of 3 ; In T 1 <ΔT<T 5 In the case of 4 ; When ΔT = T 1 In the case of 5 ; Among them, T 3 is the third temperature threshold, T 4 is the fourth temperature threshold; T 5 is the fifth temperature threshold; v 5 <v 1 <v 2 <v 3 <v 4 .

7. The control method according to any one of claims 1 to 4, It is characterized in that The chiller executes a preset quick start mode including: Adjusting the operating frequency of the compressor of the chiller to a preset operating frequency; The compressor of the chiller is controlled to operate at the preset operating frequency for a preset time.

8. A control device for a chiller, comprising a processor and a memory storing program instructions, It is characterized in that The processor is configured to execute the control method for a chiller according to any one of claims 1 to 7 when running the program instructions.

9. A chiller, It is characterized in that include: Chiller body; A compressor, arranged on the chiller body; and, The control device for a chiller according to claim 8 is installed on the chiller body.

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