Standby control method, device and system, unit and storage medium

Abstract

The invention provides a standby control method, device and system, a unit and a storage medium. After the parallel screw unit is in a standby state, a current first temperature threshold value and the current refrigerant temperature of a refrigerant in an evaporator can be obtained firstly, then the first temperature threshold value is corrected based on the refrigerant temperature, and therefore the corrected first temperature threshold value is obtained; and then the corrected first temperature threshold value is used for continuously controlling operation of the parallel screw unit until the parallel screw unit enters the standby state again, and a new first temperature threshold value is corrected again based on the current refrigerant temperature after standby in a circulating manner. Therefore, the influence of evaporator icing, dirt, load and other changes on the parallel screw unit is reduced, the parallel screw unit is more accurately controlled to be standby under the condition that the required temperature is met, the energy consumption of the parallel logic unit is reduced, the control precision of the parallel screw unit is improved, and the operation stability of the parallel screw unit is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of parallel screw units, and in particular to a standby control method, device, system, unit and storage medium. Background Art

[0002] Parallel screw units generally have the characteristics of a wide range of evaporation temperatures (i.e., the temperature of the refrigerant in the evaporator) and high stability, and are therefore widely used in different industries such as food processing, quick freezing, medicine, chemical industry, and military research. Parallel screw units usually monitor the temperature of the refrigerant in the evaporator to control the operating status of the unit, and the unit will be on standby when the temperature of the refrigerant reaches the set temperature range. Due to changes in evaporator icing, dirt, and load, the temperature difference between the refrigerant temperature and the regulated space will also change, which will cause problems such as standby before reaching the required temperature and still running when the required temperature is reached. This is not conducive to accurate control of the unit and will increase the energy consumption and operational instability of the unit. Summary of the invention

[0003] In view of this, in order to solve the technical problem in the prior art that due to changes in the evaporator such as ice, dirt and load, the temperature of the refrigerant and the temperature difference between the conditioned space will also change accordingly, which will cause the unit to be in standby mode before the required temperature is reached and still run when the required temperature is reached, which is not conducive to precise control of the unit and will increase the energy consumption of the unit and the instability of operation, the present disclosure provides a standby control method, device, system, unit and storage medium.

[0004] According to a first aspect of an embodiment of the present disclosure, a standby control method is provided, which is applied to a parallel screw unit, and the standby control method includes:

[0005] After the parallel screw unit is in a standby state, obtaining a current first temperature threshold of the parallel screw unit and a current refrigerant temperature of the refrigerant in the evaporator of the parallel screw unit; wherein the first temperature threshold is the highest temperature value of the parallel screw unit when entering the standby state;

[0006] Correcting the current first temperature threshold based on the current refrigerant temperature to determine a corrected first temperature threshold;

[0007] The parallel screw units are controlled to operate based on the corrected first temperature threshold until the parallel screw units enter a standby state again.

[0008] In an alternative embodiment,

[0009] The correcting the current first temperature threshold based on the current refrigerant temperature to determine a corrected first temperature threshold includes:

[0010] Determine a temperature difference between the first current temperature threshold and the current refrigerant temperature;

[0011] Determine a correction coefficient ξ of the first temperature threshold based on at least one parameter of a thermal conductivity λ, a convection heat transfer coefficient h, and a radiation heat transfer coefficient σ corresponding to the evaporator;

[0012] A corrected first temperature threshold is determined based on the current first temperature threshold, the temperature difference, and the correction coefficient.

[0013] In an alternative embodiment,

[0014] The determining of the correction coefficient ξ of the first temperature threshold based on at least one parameter of a thermal conductivity λ, a convection heat transfer coefficient h, and a radiation heat transfer coefficient σ corresponding to the evaporator includes:

[0015] Obtain a first constant K1 corresponding to the thermal conductivity λ, a second constant K2 corresponding to the convection heat transfer coefficient h, and a third constant K3 corresponding to the radiation heat transfer coefficient σ;

[0016] The correction factor ξ is determined based on the following formula:

[0017] In an alternative embodiment,

[0018] The control method comprises:

[0019] Based on the current refrigerant temperature and the target setting temperature of the parallel screw unit, the first constant K1 is adjusted; wherein, the greater the difference between the current refrigerant temperature and the target setting temperature, the greater the first constant K1;

[0020] and / or,

[0021] The second constant K2 is adjusted based on the current refrigerant temperature and the target setting temperature of the parallel screw unit; wherein, the greater the difference between the current refrigerant temperature and the target setting temperature, the greater the second constant K2.

[0022] In an alternative embodiment,

[0023] The adjusting the first constant K1 based on the current refrigerant temperature and the target set temperature of the parallel screw unit includes:

[0024] Acquire first configuration information; wherein the first configuration information includes a plurality of first constant setting values ​​and a plurality of first temperature intervals, and the plurality of first constant setting values ​​correspond one to one with the plurality of first temperature intervals;

[0025] The first constant K1 after adjustment is determined by taking the first constant setting value corresponding to the first temperature interval to which the difference between the current refrigerant temperature and the target setting temperature belongs.

[0026] In an alternative embodiment,

[0027] The adjusting the second constant K2 based on the current refrigerant temperature and the target set temperature of the parallel screw unit includes:

[0028] Acquire second configuration information; wherein the second configuration information includes a plurality of second constant setting values ​​and a plurality of second temperature intervals, and the plurality of second constant setting values ​​correspond one to one to the plurality of second temperature intervals;

[0029] The second constant K2 after adjustment is determined by taking the second constant setting value corresponding to the second temperature interval to which the difference between the current refrigerant temperature and the target setting temperature belongs.

[0030] In an alternative embodiment,

[0031] The thermal conductivity λ is determined by:

[0032] Determining the thermal conductivity λ based on the unit load of the parallel screw unit, the heat transfer area of ​​the evaporator, the wall thickness of the heat exchange tube in the evaporator, the temperature of the refrigerant in the evaporator, and the target setting temperature of the parallel screw unit;

[0033] and / or,

[0034] The flow heat transfer coefficient h is determined by the following method:

[0035] Determining the flow heat transfer coefficient h based on the unit load, the heat transfer area, the temperature of the refrigerant in the evaporator and the target set temperature;

[0036] and / or,

[0037] The radiation heat transfer coefficient σ is determined by the following method:

[0038] The radiation heat transfer coefficient σ is determined based on the heat transfer area, the emissivity of the outer surface of the evaporator, the emissivity of the solid surface of the conditioned space, and the Stefan-Boltzmann constant.

[0039] In an alternative embodiment,

[0040] The controlling the operation of the parallel screw units based on the corrected first temperature threshold until the parallel screw units enter the standby state again includes:

[0041] Based on the corrected first temperature threshold, determining a corrected second temperature threshold; wherein the second temperature threshold is the lowest temperature value at which the parallel screw unit exits the standby state;

[0042] If it is determined that the temperature of the refrigerant in the evaporator is greater than or equal to the second temperature threshold, controlling the parallel screw unit to exit the standby state;

[0043] After the parallel screw unit exits the standby state, if it is determined that the temperature of the refrigerant in the evaporator is less than or equal to the first temperature threshold, the parallel screw unit is controlled to enter the standby state again.

[0044] According to a second aspect of an embodiment of the present disclosure, a standby control device is provided, which is applied to a parallel screw unit, and the standby control device includes:

[0045] an acquisition module, configured to acquire, after the parallel screw unit is in a standby state, a current first temperature threshold of the parallel screw unit and a current refrigerant temperature of the refrigerant in the evaporator of the parallel screw unit;

[0046] a determination module, configured to correct the current first temperature threshold based on the current refrigerant temperature to determine a corrected first temperature threshold;

[0047] The control module is used to control the operation of the parallel screw units based on the corrected first temperature threshold until the parallel screw units enter the standby state again.

[0048] According to a third aspect of an embodiment of the present disclosure, there is provided a standby control system, which is applied to a parallel screw unit, and the standby control system is configured to execute the standby control method as described in any one of the first aspects.

[0049] According to a fourth aspect of an embodiment of the present disclosure, a parallel screw unit is provided, the parallel screw unit comprising:

[0050] processor;

[0051] a memory for storing instructions executable by the processor;

[0052] Wherein, the processor is configured to execute the standby control method as described in any one of the first aspects.

[0053] According to the fifth aspect of the embodiment of the present disclosure, a non-temporary computer-readable storage medium is provided. When the instructions in the storage medium are executed by the processor of the parallel screw unit, the parallel screw unit can execute the standby control method as described in any one of the first aspects.

[0054] The technical solution provided by the embodiments of the present disclosure may include the following beneficial effects: In the present disclosure, after the parallel screw unit is in the standby state, the current first temperature threshold and the current refrigerant temperature of the refrigerant in the evaporator can be obtained first, and then the first temperature threshold is corrected based on the refrigerant temperature to obtain the corrected first temperature threshold, and then the corrected first temperature threshold is used to continue to control the operation of the parallel screw unit until the parallel screw unit enters the standby state again, and the new first temperature threshold is re-corrected based on the current refrigerant temperature after standby in this cycle, thereby reducing the impact of changes such as evaporator icing, dirt and load on the parallel screw unit, more accurately controlling the parallel screw unit to standby while meeting the required temperature, reducing the energy consumption of the parallel logic unit, improving the control accuracy of the parallel screw unit, and improving the stability of the operation of the parallel screw unit.

[0055] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0057] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0058] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0059] Figure 1 is a schematic diagram showing a standby control method according to an exemplary embodiment.

[0060] Figure 2 is a schematic diagram showing a standby control method according to another exemplary embodiment.

[0061] Figure 3 is a logic diagram of a standby control method according to an exemplary embodiment.

[0062] Figure 4 is a block diagram of a standby control device according to an exemplary embodiment

[0063] Figure 5It is a schematic diagram of the system principle of a parallel screw unit according to an exemplary embodiment.

[0064] Figure 6 is a block diagram of a parallel screw unit according to an exemplary embodiment. DETAILED DESCRIPTION

[0065] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0066] The disclosure below provides many different embodiments or examples to implement different schemes of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0067] For ease of description, spatial relative terms may be used herein to describe the relative positional relationship or movement of one element or feature relative to another element or feature as shown in the figure, such as "inside", "outside", "inner side", "outer side", "below", "below", "above", "above", "front", "back", etc. Such spatial relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure undergoes a position flip or a posture change or a motion state change, then these directional indications also change accordingly, for example: an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented as "above other elements or features" or "above other elements or features". Therefore, the example term "below..." may include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions) and the spatial relative descriptors used herein are interpreted accordingly.

[0068] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application, and thus the drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0069] The following will describe the implementation methods of the present application with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be understood that the preferred embodiments are only for illustrating the present application, not for limiting the scope of protection of the present application.

[0070] In order to solve the technical problem in the prior art that due to changes in the evaporator such as ice, dirt and load, the temperature of the refrigerant and the temperature difference between the conditioned space will also change accordingly, which will cause the unit to be in standby mode before the required temperature is reached and still run after the required temperature is reached, which is not conducive to precise control of the unit and will increase the energy consumption of the unit and the instability of operation, the present disclosure provides a standby control method, device, system, equipment and storage medium.

[0071] Among them, in the present disclosure, after the parallel screw unit is in the standby state, the current first temperature threshold and the current refrigerant temperature of the refrigerant in the evaporator can be obtained first, and then the first temperature threshold is corrected based on the refrigerant temperature to obtain the corrected first temperature threshold, and then the corrected first temperature threshold is used to continue to control the operation of the parallel screw unit until the parallel screw unit enters the standby state again, and the new first temperature threshold is re-corrected based on the current refrigerant temperature after standby in this cycle, thereby reducing the impact of changes such as evaporator icing, dirt and load on the parallel screw unit, more accurately controlling the parallel screw unit to standby while meeting the required temperature, reducing the energy consumption of the parallel logic unit, improving the control accuracy of the parallel screw unit, and improving the stability of the operation of the parallel screw unit.

[0072] In an exemplary embodiment, a standby control method is provided, which can be applied to a parallel screw unit. The parallel screw unit is mainly composed of multiple screw compressors connected in parallel, which work together to meet different load requirements. This unit is widely used in many fields such as industrial refrigeration, commercial air conditioning, and large refrigeration facilities. In this embodiment, the parallel screw unit includes at least two parallel screw compressors, and may also include other devices such as evaporators to meet refrigeration needs.

[0073] refer to Figure 1 As shown, the standby control method may include:

[0074] S110, after the parallel screw unit is in a standby state, obtaining a current first temperature threshold of the parallel screw unit and a current refrigerant temperature of the refrigerant in the evaporator of the parallel screw unit;

[0075] S120, correcting the current first temperature threshold based on the current refrigerant temperature to determine a corrected first temperature threshold;

[0076] S130. Control the operation of the parallel screw units based on the corrected first temperature threshold until the parallel screw units enter the standby state again.

[0077] In step S110, the first temperature threshold is the maximum temperature value for the parallel screw unit to enter the standby state. That is, when the parallel screw unit is in operation, if the temperature of the refrigerant in the evaporator of the parallel screw unit drops to the second standby temperature limit value, the parallel screw unit can be controlled to enter the standby state and the temperature regulation of the regulated space is suspended.

[0078] When the parallel screw unit is in the standby state, if the temperature of the refrigerant in the evaporator rises to the first temperature threshold, the parallel screw unit can be controlled to exit the standby state and continue to regulate the temperature of the regulated space.

[0079] It should be noted that, in general, a second temperature threshold is also provided in the parallel screw unit. The difference between the first temperature threshold and the second temperature threshold (recorded as the standby temperature difference) is fixed. The second temperature threshold is the minimum temperature value for the parallel screw unit to exit the standby state. The second temperature threshold is greater than the first temperature threshold. When the parallel screw unit is in the standby state, if the temperature of the refrigerant in the evaporator rises to the second temperature threshold, the parallel screw unit can be controlled to exit the standby state and continue to adjust the temperature of the regulated space.

[0080] In this step, after the parallel screw unit is in the standby state, the current first temperature threshold value can be obtained from the parallel screw unit, and the current temperature of the refrigerant in the evaporator of the parallel screw unit can be obtained, which is recorded as the current refrigerant temperature. The first temperature threshold value can be stored in the memory of the parallel screw unit. The temperature of the refrigerant can be detected by a temperature detection device arranged on the evaporator. The temperature detection device can be, for example, a temperature sensor.

[0081] It should be noted that, in addition to obtaining the first temperature threshold and the current refrigerant temperature in the above manner, they may also be obtained in other manners, which are not limited thereto.

[0082] In step S120, after the current first temperature threshold and the current refrigerant temperature are obtained, the first temperature threshold can be corrected by the current refrigerant temperature, so as to obtain a first temperature threshold that is more suitable for the current state of the parallel screw unit.

[0083] It should be noted that in the related art, the first temperature threshold of the parallel screw unit is generally preset in advance and fixed. However, as the evaporator freezes, dirt and load change, the temperature difference between the refrigerant temperature and the conditioned space will also change, resulting in that when the refrigerant temperature reaches the condition to enter standby, the temperature of the conditioned space may not reach the condition to enter standby; or when the refrigerant temperature reaches the condition to exit standby, the temperature of the conditioned space may not reach the condition to exit standby. In other words, the previously calibrated first temperature threshold may not meet the control requirements of the parallel screw unit.

[0084] In this embodiment, by using the current refrigerant temperature to correct the first temperature threshold, the influence of changes such as evaporator icing, dirt, and load on the difference between the refrigerant temperature and the temperature of the conditioned space can be better avoided.

[0085] In this embodiment, a correction coefficient can be configured in the parallel screw unit. When the current first temperature threshold is corrected based on the current refrigerant temperature, the difference between the current refrigerant temperature and the first standby temperature limit value in the current first temperature threshold can be calculated first, and then the product of the correction coefficient and the difference can be calculated, and finally the sum of the current first standby temperature limit value and the product can be determined as the corrected first standby temperature limit value.

[0086] It should be noted that the correction coefficient can be fixed or non-fixed, and there is no limitation on this.

[0087] In step S130, after obtaining the corrected first temperature threshold, the operation of the parallel screw unit can be controlled based on the corrected first temperature threshold. It should be noted that the parallel screw unit is already in standby mode at this time. Therefore, the corrected second temperature threshold can be determined based on the corrected first temperature threshold; wherein the second temperature threshold is the minimum temperature value for the parallel screw unit to exit the standby mode. Since the first temperature threshold and the second temperature threshold are generally fixed, the corrected second temperature threshold can be determined based on the standby temperature difference and the first temperature threshold. Of course, the corrected second temperature threshold can also be determined by referring to the correction method of the first temperature threshold, and there is no limitation on this.

[0088] In this step, when the parallel screw unit is in standby mode, the temperature of the refrigerant in the evaporator can be monitored. If it is determined that the temperature of the refrigerant in the evaporator is greater than or equal to the second temperature threshold, it means that the temperature of the refrigerant in the evaporator can no longer meet the temperature regulation demand. The parallel screw unit can be controlled to exit the standby mode and perform refrigeration to lower the temperature of the refrigerant, thereby better meeting the refrigeration demand of the regulated space.

[0089] After the parallel screw unit exits the standby state, the temperature of the refrigerant can continue to be monitored. If it is determined that the temperature of the refrigerant in the evaporator is less than or equal to the first temperature threshold, it means that the temperature of the refrigerant is low enough, and the parallel screw unit can be controlled to enter the standby state again. After the parallel screw unit enters the standby state again, the current first temperature threshold of the parallel screw unit and the current refrigerant temperature of the refrigerant in the evaporator of the parallel screw unit can be re-acquired, and then subsequent operations can be performed, and the cycle is repeated.

[0090] In this embodiment, after the parallel screw unit is in the standby state, the current first temperature threshold and the current refrigerant temperature of the refrigerant in the evaporator can be obtained first, and then the first temperature threshold is corrected based on the refrigerant temperature to obtain the corrected first temperature threshold, and then the corrected first temperature threshold is used to continue to control the operation of the parallel screw unit until the parallel screw unit enters the standby state again. The new first temperature threshold is re-corrected based on the current refrigerant temperature after standby in this cycle, thereby reducing the impact of changes such as evaporator icing, dirt and load on the parallel screw unit, more accurately controlling the parallel screw unit to standby while meeting the required temperature, reducing the energy consumption of the parallel logic unit, improving the control accuracy of the parallel screw unit, and improving the stability of the operation of the parallel screw unit.

[0091] In an exemplary embodiment, a standby control method is provided, which can be applied to a parallel screw compressor unit. Figures 1 to 3 As shown, in the standby control method, the current first temperature threshold is corrected based on the current refrigerant temperature to determine the corrected first temperature threshold, which may include:

[0092] S210, determining a temperature difference between a current first temperature threshold and a current refrigerant temperature;

[0093] S220, determining a correction coefficient of the first temperature threshold based on at least one parameter of a thermal conductivity, a convection heat transfer coefficient, and a radiation heat transfer coefficient corresponding to the evaporator;

[0094] S230: Determine a corrected first temperature threshold based on the current first temperature threshold, the temperature difference, and the correction coefficient.

[0095] In step S210, the current first temperature threshold may be recorded as Tm, the current refrigerant temperature may be recorded as T0, and the temperature difference may be recorded as Δt, where Δt=Tm-T0.

[0096] In step S220, it should be noted that the correction coefficient is mainly used to compensate for external uncertain conditions (such as changing load, evaporator icing, etc.), and is set to a number greater than 0. The correction coefficient ξ can be a fixed value or an adjustable value, which is not limited.

[0097] Among them, the correction coefficient ξ may be related to the thermal conductivity λ, the convective heat transfer coefficient h, the radiation heat transfer coefficient σ, etc. In this step, the correction coefficient ξ of the first temperature threshold can be determined based on at least one parameter of the thermal conductivity λ, the convective heat transfer coefficient h, and the radiation heat transfer coefficient σ corresponding to the evaporator to improve the reliability of the correction coefficient ξ. For example, the final correction coefficient ξ can be comprehensively determined based on the thermal conductivity λ, the convective heat transfer coefficient h, and the radiation heat transfer coefficient σ corresponding to the above-mentioned evaporator to better ensure the reliability of the correction coefficient ξ, thereby better improving the control accuracy of the parallel screw unit.

[0098] The thermal conductivity λ can be determined based on the unit load of the parallel screw unit, the heat transfer area of ​​the evaporator, the wall thickness of the heat exchange tube in the evaporator, the temperature of the refrigerant in the evaporator, and the target set temperature of the parallel screw unit: Where Q is the unit load of the parallel screw unit, in W; A is the heat transfer area of ​​the evaporator, in m 2 ; T1 is the temperature of the refrigerant in the evaporator, and the current refrigerant temperature T0 can be used directly here; T2 is the target set temperature of the parallel screw unit, that is, the temperature that the regulated space needs to reach that is set manually; L is the wall thickness of the heat exchange tube in the evaporator, in meters.

[0099] The flow heat transfer coefficient h can be determined based on the unit load Q, the heat transfer area A, the temperature T1 of the refrigerant in the evaporator, and the target set temperature T2:

[0100] The radiation heat transfer coefficient σ can be determined based on the heat transfer area A, the emissivity ε1 of the outer surface of the evaporator, the emissivity ε2 of the solid surface of the conditioned space, and the Stefan-Boltzmann constant θ: After the parallel screw unit is determined, the emissivity ε1 of the outer surface of the evaporator and the emissivity ε2 of the solid surface of the conditioned space are generally fixed values.

[0101] In this step, after determining the thermal conductivity λ, convection heat transfer coefficient h and radiation heat transfer coefficient σ corresponding to the evaporator, the correction coefficient ζ=f(λ, h, σ) can be determined based on the above parameters. That is to say, the size of the correction coefficient is mainly related to the unit load Q and the refrigerant temperature T1.

[0102] Among them, f in ζ=f(λ, h, σ) can be determined based on simulation experiments or parameter fitting, and its specific function is not limited.

[0103] In some embodiments,

[0104] Wherein, K1 is the first constant corresponding to the thermal conductivity λ, K2 is the second constant corresponding to the convection heat transfer coefficient h, and K3 is the third constant corresponding to the radiation heat transfer coefficient σ.

[0105] That is to say, in this embodiment, the first constant K1 corresponding to the thermal conductivity λ, the second constant K2 corresponding to the convective heat transfer coefficient h, and the third constant K3 corresponding to the radiation heat transfer coefficient σ can be obtained first, and then the correction coefficient ξ is determined based on the following formula:

[0106] Among them, the difference between the current refrigerant temperature and the target setting temperature is different, and the heat exchange dominant factor of the evaporator may change. In order to adapt to the above changes, the first constant K1 and the second constant K2 can be set to be variable. In this embodiment, it can be set as follows: the greater the difference between the current refrigerant temperature and the target setting temperature, the greater the first constant K1; the greater the difference between the current refrigerant temperature and the target setting temperature, the greater the second constant K2.

[0107] In this embodiment, when determining the correction coefficient, the first constant K1 can be adjusted based on the current refrigerant temperature and the target set temperature of the parallel screw unit. Among them, the first configuration information can be stored in the parallel screw unit, and the first configuration information can include multiple first constant setting values ​​and multiple first temperature intervals, and the multiple first constant setting values ​​correspond to the multiple first temperature intervals one by one. It should be noted that the first configuration information can be configured according to actual conditions, and its specific content may not be limited. In addition, the first configuration information is subsequently modified according to actual needs to better ensure the control accuracy of the parallel screw unit.

[0108] Among them, when adjusting the first constant K1, the first configuration information can be obtained, and the difference between the current refrigerant temperature and the target set temperature can be determined, and then the first temperature interval to which the above difference belongs in the first configuration information is determined as the target first temperature interval, and then the first constant setting value corresponding to the above target first temperature interval is determined as the adjusted first constant K1.

[0109] Similarly, the second configuration information may be stored in the parallel screw unit, and the second configuration information may include multiple second constant setting values ​​and multiple second temperature intervals, and the multiple second constant setting values ​​correspond to the multiple second temperature intervals one by one. It should be noted that the second configuration information may be configured according to actual conditions, and its specific content may not be limited. In addition, the second configuration information may be modified later according to actual needs to better ensure the control accuracy of the parallel screw unit.

[0110] Among them, when adjusting the second constant K2, the second configuration information can be obtained, and the difference between the current refrigerant temperature and the target set temperature can be determined, and then the second temperature interval to which the above difference belongs in the second configuration information is determined as the target second temperature interval, and then the second constant setting value corresponding to the above target second temperature interval is determined as the adjusted second constant K2.

[0111] After determining the first constant K1, the second constant K2 and the third constant K3, we can use the formula Determine the correction factor ξ.

[0112] It should be noted that, in addition to determining the correction coefficient ξ in the above manner, it can also be determined in other manners, which are not limited. In addition, in order to simplify the control logic, the first constant K1 and the second constant K2 can also be set to fixed values, which are not limited.

[0113] In step S230, after determining the correction coefficient ξ, the current first temperature threshold and the temperature difference, the corrected first temperature threshold Tm=Tn+ξ*△t can be determined based on the following formula. Tn is the original first temperature threshold, that is, the current first temperature threshold; Tm is the newly determined first temperature threshold, that is, the corrected first temperature threshold. After obtaining the new first temperature threshold, the first temperature threshold stored in the parallel screw unit can be updated.

[0114] After the first temperature threshold is updated, the parallel screw unit can be controlled to operate based on the updated first temperature threshold. At this time, the parallel screw unit is still in standby mode. When the parallel screw unit is in standby mode, the temperature of the refrigerant in the evaporator can be monitored. If it is determined that the temperature of the refrigerant in the evaporator is greater than or equal to the second temperature threshold, it means that the temperature of the refrigerant in the evaporator can no longer meet the temperature regulation requirements. The parallel screw unit can be controlled to exit the standby mode and perform refrigeration to reduce the temperature of the refrigerant, thereby better meeting the refrigeration requirements of the regulated space.

[0115] After the parallel screw unit exits the standby state, the temperature of the refrigerant (which can be recorded as Te) can continue to be monitored. If it is determined that the temperature of the refrigerant in the evaporator is less than or equal to the first temperature threshold, it means that the temperature of the refrigerant is low enough, and the parallel screw unit can be controlled to enter the standby state again. After the parallel screw unit is unloaded, it stands by and then recycles to learn and correct the first temperature threshold. That is, after the parallel screw unit enters the standby state again, the current first temperature threshold of the parallel screw unit and the current refrigerant temperature of the refrigerant in the evaporator of the parallel screw unit can be re-acquired, and then subsequent operations are performed, and the cycle is repeated, thereby reducing the impact of changes such as evaporator icing, dirt and load on the parallel screw unit, more accurately controlling the parallel screw unit to stand by while meeting the required temperature, reducing the energy consumption of the parallel logic unit, improving the control accuracy of the parallel screw unit, and improving the stability of the operation of the parallel screw unit.

[0116] In this standby control method, by continuously implementing incremental adjustments and conducting autonomous learning, the temperature of the regulated space is ultimately equal to the required temperature when the unit is on standby. This method can effectively control the standby of the parallel screw unit, improve control accuracy, reduce energy consumption, and improve the operating stability and reliability of the parallel screw unit.

[0117] In an exemplary embodiment, a standby control device is provided, which is applied to a parallel screw compressor unit. The device is used to implement a standby control method of an upper tree. For example, referring to Figure 4 As shown, the device may include an acquisition module 10 , a determination module 20 and a control module 30 .

[0118] An acquisition module 10, for acquiring a current first temperature threshold of the parallel screw unit and a current refrigerant temperature of the refrigerant in the evaporator of the parallel screw unit after the parallel screw unit is in a standby state;

[0119] A determination module 20, configured to correct the current first temperature threshold based on the current refrigerant temperature to determine a corrected first temperature threshold;

[0120] The control module 30 is used to control the operation of the parallel screw units based on the corrected first temperature threshold until the parallel screw units enter the standby state again.

[0121] In an exemplary embodiment, a standby control device is provided, which is applied to a parallel screw compressor unit. Figure 4 As shown, in the device, the determination module 20 can be used to:

[0122] Determine a temperature difference between the first current temperature threshold and the current refrigerant temperature;

[0123] Determine a correction coefficient ξ of the first temperature threshold based on at least one parameter of a thermal conductivity λ, a convection heat transfer coefficient h, and a radiation heat transfer coefficient σ corresponding to the evaporator;

[0124] A corrected first temperature threshold is determined based on the current first temperature threshold, the temperature difference, and the correction coefficient.

[0125] In an exemplary embodiment, a standby control device is provided, which is applied to a parallel screw compressor unit. Figure 4 As shown, in the device,

[0126] An acquisition module 10, which can be used to acquire a first constant K1 corresponding to the thermal conductivity λ, a second constant K2 corresponding to the convection heat transfer coefficient h, and a third constant K3 corresponding to the radiation heat transfer coefficient σ;

[0127] The determination module 20 may be used to determine the correction coefficient ξ based on the following formula:

[0128] In an exemplary embodiment, a standby control device is provided, which is applied to a parallel screw compressor unit. Figure 4 As shown, in the device, the determination module 20 can be used to:

[0129] Based on the current refrigerant temperature and the target setting temperature of the parallel screw unit, the first constant K1 is adjusted; wherein, the greater the difference between the current refrigerant temperature and the target setting temperature, the greater the first constant K1;

[0130] and / or,

[0131] The second constant K2 is adjusted based on the current refrigerant temperature and the target setting temperature of the parallel screw unit; wherein, the greater the difference between the current refrigerant temperature and the target setting temperature, the greater the second constant K2.

[0132] In an exemplary embodiment, a standby control device is provided, which is applied to a parallel screw compressor unit. Figure 4 As shown, in the device, the determination module 20 can be used to:

[0133] Acquire first configuration information; wherein the first configuration information includes a plurality of first constant setting values ​​and a plurality of first temperature intervals, and the plurality of first constant setting values ​​correspond one to one with the plurality of first temperature intervals;

[0134] The first constant K1 after adjustment is determined by taking the first constant setting value corresponding to the first temperature interval to which the difference between the current refrigerant temperature and the target setting temperature belongs.

[0135] In an exemplary embodiment, a standby control device is provided, which is applied to a parallel screw compressor unit. Figure 4 As shown, in the device, the determination module 20 can be used to:

[0136] Acquire second configuration information; wherein the second configuration information includes a plurality of second constant setting values ​​and a plurality of second temperature intervals, and the plurality of second constant setting values ​​correspond one to one to the plurality of second temperature intervals;

[0137] The second constant K2 after adjustment is determined by taking the second constant setting value corresponding to the second temperature interval to which the difference between the current refrigerant temperature and the target setting temperature belongs.

[0138] In an exemplary embodiment, a standby control device is provided, which is applied to a parallel screw compressor unit. Figure 4 As shown, in the device, the determination module 20 can be used to:

[0139] Determining the thermal conductivity λ based on the unit load of the parallel screw unit, the heat transfer area of ​​the evaporator, the wall thickness of the heat exchange tube in the evaporator, the temperature of the refrigerant in the evaporator, and the target setting temperature of the parallel screw unit;

[0140] and / or,

[0141] Determining the flow heat transfer coefficient h based on the unit load, the heat transfer area, the temperature of the refrigerant in the evaporator and the target set temperature;

[0142] and / or,

[0143] The radiation heat transfer coefficient σ is determined based on the heat transfer area, the emissivity of the outer surface of the evaporator, the emissivity of the solid surface of the conditioned space, and the Stefan-Boltzmann constant.

[0144] In an exemplary embodiment, a standby control device is provided, which is applied to a parallel screw compressor unit. Figure 4 As shown, in the device, the control module 30 can be used to:

[0145] Based on the corrected first temperature threshold, determining a corrected second temperature threshold; wherein the second temperature threshold is the lowest temperature value at which the parallel screw unit exits the standby state;

[0146] If it is determined that the temperature of the refrigerant in the evaporator is greater than or equal to the first standby temperature limit value, controlling the parallel screw unit to exit the standby state;

[0147] After the parallel screw unit exits the standby state, if it is determined that the temperature of the refrigerant in the evaporator is less than or equal to the second standby temperature limit value, the parallel screw unit is controlled to enter the standby state again.

[0148] In an exemplary embodiment, a standby control system is provided, which is applied to a parallel screw compressor unit and is configured to execute the standby control method in the above embodiment to realize standby control of the parallel screw compressor unit.

[0149] In an exemplary embodiment, a parallel screw compressor unit is provided. Figure 5 As shown, the parallel screw unit may include a compressor 1, an oil separator 2, a condenser 3, an electronic expansion valve 4, an evaporator 5, an oil cooler 6 and a processor 101, etc.

[0150] In the parallel screw unit, the refrigerant and the refrigeration oil enter the oil separator 2 after being compressed by the compressor 1. The refrigerant gas separated by the oil separator 2 enters the condenser 3, and the refrigeration oil enters the oil cooler 6, and then returns to the compressor 1. After the refrigerant comes out of the condenser 3, it passes through the electronic expansion valve 4, enters the evaporator 5 after being throttled by the electronic expansion valve 4, and returns to the compressor 1 after absorbing heat in the evaporator 5.

[0151] Among them, in this embodiment, the parallel screw unit can read the refrigerant temperature in the evaporator 5 and the current first temperature threshold when the parallel screw unit is on standby through the processor 101, and then correct the first temperature threshold of the parallel screw unit through the standby control method in the above embodiment, thereby achieving the effect of accurately controlling the standby of the parallel screw unit, reducing the energy consumption of the parallel screw unit, and increasing the operating stability of the parallel screw unit.

[0152] It should be noted that the parallel screw unit generally does not control the standby of the unit by the terminal temperature, but stands by when the temperature of the refrigerant in the evaporator 5 of the unit reaches the set first temperature threshold. There is a certain temperature difference between the temperature of the refrigerant and the terminal temperature, which is related to the heat transfer coefficient of the evaporator 5, and the heat transfer coefficient is uncontrollable. The first temperature threshold in the related technology is generally a fixed value, and the actual operation of the unit will be affected by various environmental factors, resulting in the fixed value of the first temperature threshold cannot accurately realize the control of the parallel screw unit. The parallel screw unit of this embodiment is equipped with a self-learning standby control method, which achieves the purpose of accurately controlling the standby of the parallel screw unit by continuously learning and correcting the first temperature threshold.

[0153] refer to Figure 6As shown, the parallel screw unit 100 may include: at least one processor 101, a memory 102, at least one network interface 104 and other user interfaces 103. The various components in the parallel screw unit 100 are coupled together through a bus system 105. It can be understood that the bus system 105 is used to achieve connection and communication between these components. In addition to the data bus, the bus system 105 also includes a power bus, a control bus and a status signal bus. However, for the sake of clarity, all buses are labeled as bus system 105.

[0154] The user interface 103 may include a display, a keyboard, or a click-type parallel screw unit (eg, a mouse, a trackball, a touch pad, or a touch screen).

[0155] It can be understood that the memory 102 in the embodiment of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct RAM bus random access memory (DRRAM). The memory 102 described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0156] In some implementations, the memory 102 stores the following elements, executable units or data structures, or a subset thereof, or an extended set thereof: an operating system 1021 and application programs 1022 .

[0157] Among them, the operating system 1021 includes various system programs, such as a framework layer, a core library layer, a driver layer, etc., which are used to implement various basic services and process hardware-based tasks. The application 1022 includes various application programs, such as a media player (Media Player), a browser (Browser), etc., which are used to implement various application services. The program that implements the method of the embodiment of the present application can be included in the application 1022.

[0158] In the embodiment of the present application, by calling the program or instruction stored in the memory 102, specifically, the program or instruction stored in the application 1022, the processor 101 is used to execute the method provided by each method embodiment.

[0159] The method disclosed in the above embodiment of the present application can be applied to the processor 101, or implemented by the processor 101. The processor 101 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the hardware integrated logic circuit in the processor 101 or the instruction in the form of software. The above processor 101 can be a general processor, a digital signal processor (Digital Signal Processor, DSP), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field programmable gate array (Field Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiment of the present application can be directly embodied as a hardware decoding processor to execute, or the hardware and software units in the decoding processor can be executed. The software unit can be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 102, and the processor 101 reads the information in the memory 102 and completes the above method in combination with its hardware.

[0160] It is understood that the embodiments described herein may be implemented in hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit may be implemented in one or at least one application specific integrated circuit (ASIC), digital signal processor (DSP), digital signal processing parallel screw unit (DSPDevice, DSPD), programmable logic parallel screw unit (PLD), field programmable gate array (FPGA), general purpose processor, controller, microcontroller, microprocessor, other electronic unit for performing the functions described in the present application, or a combination thereof.

[0161] For software implementation, the technology described herein can be implemented by a unit that performs the functions described herein. The software code can be stored in a memory and executed by a processor. The memory can be implemented in the processor or outside the processor.

[0162] The embodiment of the present application also provides a storage medium (computer-readable storage medium). The storage medium here stores one or at least one program. The storage medium may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a read-only memory, a flash memory, a hard disk or a solid-state drive; the memory may also include a combination of the above-mentioned types of memory.

[0163] When one or at least one program in the storage medium can be executed by one or at least one processor. When the storage medium is applied to a parallel screw unit, the above method for executing the parallel screw unit can be implemented. The processor is used to execute the control program of the parallel screw unit stored in the memory to implement the above method for executing the parallel screw unit.

[0164] The professionals should also be further aware that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented with electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0165] It should be noted that the phrases "one implementation", "an embodiment", "an exemplary embodiment", "some embodiments", etc. mentioned in the specification indicate that the described embodiments may include certain features, structures or characteristics, but not every embodiment may include the certain features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when describing certain features, structures or characteristics in conjunction with an embodiment, it is within the knowledge of those skilled in the art to implement such features, structures or characteristics in conjunction with other embodiments, whether explicitly or not explicitly described.

[0166] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or electronic device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or electronic device. In the absence of more limitations, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or electronic device including the elements.

[0167] The above embodiments are only preferred embodiments for fully illustrating the present application, and the protection scope of the present application is not limited thereto. Any equivalent substitution or change made by a person skilled in the art based on the present application is within the protection scope of the present application.

Claims

1. A standby control method, applied to a parallel screw compressor unit, characterized in that: The standby control method comprises: After the parallel screw unit is in a standby state, obtaining a current first temperature threshold of the parallel screw unit and a current refrigerant temperature of the refrigerant in the evaporator of the parallel screw unit; wherein the first temperature threshold is the highest temperature value of the parallel screw unit when entering the standby state; Correcting the current first temperature threshold based on the current refrigerant temperature to determine a corrected first temperature threshold; The parallel screw units are controlled to operate based on the corrected first temperature threshold until the parallel screw units enter a standby state again.

2. The standby control method according to claim 1, characterized in that: The correcting the current first temperature threshold based on the current refrigerant temperature to determine a corrected first temperature threshold includes: Determine a temperature difference between the first current temperature threshold and the current refrigerant temperature; Determine a correction coefficient ξ of the first temperature threshold based on at least one parameter of a thermal conductivity λ, a convection heat transfer coefficient h, and a radiation heat transfer coefficient σ corresponding to the evaporator; Based on the current first temperature threshold, the temperature difference, and the correction coefficient, a corrected first temperature threshold is determined.

3. The standby control method according to claim 2, characterized in that: The determining of the correction coefficient ξ of the first temperature threshold based on at least one parameter of a thermal conductivity λ, a convection heat transfer coefficient h, and a radiation heat transfer coefficient σ corresponding to the evaporator includes: Obtain a first constant K1 corresponding to the thermal conductivity λ, a second constant K2 corresponding to the convection heat transfer coefficient h, and a third constant K3 corresponding to the radiation heat transfer coefficient σ; The correction factor ξ is determined based on the following formula:

4. The standby control method according to claim 3, characterized in that: The control method comprises: Based on the current refrigerant temperature and the target setting temperature of the parallel screw unit, the first constant K1 is adjusted; wherein, the greater the difference between the current refrigerant temperature and the target setting temperature, the greater the first constant K1; and / or, The second constant K2 is adjusted based on the current refrigerant temperature and the target setting temperature of the parallel screw unit; wherein, the greater the difference between the current refrigerant temperature and the target setting temperature, the greater the second constant K2.

5. The standby control method according to claim 4, characterized in that: The adjusting the first constant K1 based on the current refrigerant temperature and the target set temperature of the parallel screw unit includes: Acquire first configuration information; wherein the first configuration information includes a plurality of first constant setting values ​​and a plurality of first temperature intervals, and the plurality of first constant setting values ​​correspond one to one with the plurality of first temperature intervals; The first constant K1 after adjustment is determined by taking the first constant setting value corresponding to the first temperature interval to which the difference between the current refrigerant temperature and the target setting temperature belongs.

6. The standby control method according to claim 4, characterized in that: The adjusting the second constant K2 based on the current refrigerant temperature and the target set temperature of the parallel screw unit includes: Acquire second configuration information; wherein the second configuration information includes a plurality of second constant setting values ​​and a plurality of second temperature intervals, and the plurality of second constant setting values ​​correspond one to one to the plurality of second temperature intervals; The second constant K2 after adjustment is determined by taking the second constant setting value corresponding to the second temperature interval to which the difference between the current refrigerant temperature and the target setting temperature belongs.

7. The standby control method according to claim 2, characterized in that: The thermal conductivity λ is determined by: Determining the thermal conductivity λ based on the unit load of the parallel screw unit, the heat transfer area of ​​the evaporator, the wall thickness of the heat exchange tube in the evaporator, the temperature of the refrigerant in the evaporator, and the target setting temperature of the parallel screw unit; and / or, The flow heat transfer coefficient h is determined by the following method: Determining the flow heat transfer coefficient h based on the unit load, the heat transfer area, the temperature of the refrigerant in the evaporator and the target set temperature; and / or, The radiation heat transfer coefficient σ is determined by the following method: The radiation heat transfer coefficient σ is determined based on the heat transfer area, the emissivity of the outer surface of the evaporator, the emissivity of the solid surface of the conditioned space, and the Stefan-Boltzmann constant.

8. The standby control method according to any one of claims 1 to 7, characterized in that: The controlling the operation of the parallel screw units based on the corrected first temperature threshold until the parallel screw units enter the standby state again includes: Based on the corrected first temperature threshold, determining a corrected second temperature threshold; wherein the second temperature threshold is the lowest temperature value at which the parallel screw unit exits the standby state; If it is determined that the temperature of the refrigerant in the evaporator is greater than or equal to the second temperature threshold, controlling the parallel screw unit to exit the standby state; After the parallel screw unit exits the standby state, if it is determined that the temperature of the refrigerant in the evaporator is less than or equal to the first temperature threshold, the parallel screw unit is controlled to enter the standby state again.

9. A standby control device, applied to a parallel screw compressor unit, characterized in that: The standby control device comprises: an acquisition module, configured to acquire, after the parallel screw unit is in a standby state, a current first temperature threshold of the parallel screw unit and a current refrigerant temperature of the refrigerant in the evaporator of the parallel screw unit; a determination module, configured to correct the current first temperature threshold based on the current refrigerant temperature to determine a corrected first temperature threshold; The control module is used to control the operation of the parallel screw units based on the corrected first temperature threshold until the parallel screw units enter the standby state again.

10. A standby control system, applied to a parallel screw unit, characterized in that: The standby control system is configured to execute the standby control method according to any one of claims 1 to 8.

11. A parallel screw unit, characterized in that: The parallel screw unit comprises: processor; a memory for storing instructions executable by the processor; Wherein, the processor is configured to execute the standby control method as described in any one of claims 1-8.

12. A non-transitory computer-readable storage medium, characterized in that: When the instructions in the storage medium are executed by the processor of the parallel screw unit, the parallel screw unit can execute the standby control method as described in any one of claims 1 to 8.

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