WO2019237698A1

WO2019237698A1 - Multi-split system and oil return control method and device of multi-split system

Info

Publication number: WO2019237698A1
Application number: PCT/CN2018/121673
Authority: WO
Inventors: 卜其辉; 许永锋; 梁伯启; 李宏伟; 董世龙; 吴孔祥; 吴晓鸿; 张宇
Original assignee: 广东美的暖通设备有限公司; 美的集团股份有限公司
Priority date: 2018-06-13
Filing date: 2018-12-18
Publication date: 2019-12-19
Also published as: EP3640566A1; CN108759174B; CN108759174A; US20210148615A1

Abstract

A multi-split system and an oil return control method and device of the multi-split system. The method comprises the following steps: in an operation process of the system, obtaining a minimum refrigerant flow needed for bringing lubricating oil in the system into an outdoor unit and a current refrigerant flow of the system every a first preset time; detecting and determining whether the current refrigerant flow is smaller than or equal to the minimum refrigerant flow; obtaining a total oil discharging amount of an oil return compressor from last time; detecting and determining whether the total oil discharging amount is greater than a maximum safe oil discharging amount; and controlling the system to implement oil return. Therefore, it can be guaranteed that a situation that a compressor operates in an oil starvation manner due to the large oil discharging amount and small oil return amount is avoided, the capacity and energy efficiency of the multi-split system are effectively improved, and the method is simple and practicable.

Description

多联机***及多联机***的回油控制方法、装置Multi-connection system and oil return control method and device of multi-connection system

相关申请的交叉引用Cross-reference to related applications

本申请基于申请号为201810606528.1，申请日为2018年06月13申请的中国专利申请提出，并要求该中国专利申请的优先权，该中国专利申请的全部内容在此引入本申请作为参考。This application is based on a Chinese patent application with an application number of 201810606528.1 and an application date of June 13, 2018, and claims the priority of the Chinese patent application. The entire contents of the Chinese patent application are incorporated herein by reference.

技术领域Technical field

本申请涉及制冷技术领域，特别涉及一种多联机***的回油控制方法、一种多联机***的回油控制装置和一种多联机***。The present application relates to the field of refrigeration technology, and in particular, to a method for controlling oil return of a multi-line system, a device for controlling oil return of a multi-line system, and a multi-line system.

背景技术Background technique

随着多联式空调机型(简称多联机)的不断增多，及其具有节能、智能化调节、温度控制精确、自动化程度高、使用灵活、管理方便等诸多优点，其在大型建筑及别墅的应用日益广泛。一般地，由于多联机的管路较长，能够存油的位置较多，随着***运行时间的增加，***管路中积聚的润滑油会越来越多，如果回油不及时，压缩机就会因为缺少润滑油而发生损坏。With the increasing number of multi-connected air-conditioning models (referred to as multi-connected), it has many advantages such as energy saving, intelligent adjustment, precise temperature control, high degree of automation, flexible use, and convenient management. Applications are increasingly widespread. Generally, because the multi-connected pipeline is longer, there are more locations where oil can be stored. As the system operating time increases, the accumulated lubricant in the system pipeline will be more and more. If the oil is not returned in time, the compressor Damage can occur due to lack of lubricant.

针对上述问题，常规的做法是在多联机运行固定的一段时间后进行回油运行，回油运行一般切换为制冷运行，以将***管路中的润滑油带回室外机，避免压缩机缺油运行。In response to the above problems, the conventional method is to perform oil return operation after a fixed period of multiple online operations. The oil return operation is generally switched to cooling operation to bring the lubricant in the system pipeline back to the outdoor unit to avoid the compressor ’s lack of oil. run.

然而，由于多联机运行工况不一致，在运行过程中排油量也不一致，如果运行工况排油量大，回油量少，在固定时间内可能同样会造成压缩机缺油运行。However, due to the inconsistent operating conditions of multiple on-line operations, the oil discharge volume is also inconsistent during operation. If the oil discharge volume in the operating conditions is large and the oil return is small, the compressor may also run out of oil in a fixed time.

申请内容Application content

本申请旨在至少在一定程度上解决相关技术中的技术问题之一。为此，本申请的第一个目的在于提出一种多联机***的回油控制方法，能够保证压缩机不会因排油量大，回油量小而缺油运行，有效提高多联机***的能力能效，且方法简单易行。This application is intended to solve at least one of the technical problems in the related technology. For this reason, the first purpose of this application is to propose a method for oil return control in a multi-line system, which can ensure that the compressor does not run out of oil due to large oil discharge and small oil return, which effectively improves the multi-line system. Ability and energy efficiency, and the method is simple and easy to implement.

本申请的第二个目的在于提出一种非临时性计算机可读存储介质。A second object of the present application is to propose a non-transitory computer-readable storage medium.

本申请的第三个目的在于提出一种多联机***的回油控制装置。A third object of the present application is to provide an oil return control device of a multi-online system.

本申请的第四个目的在于提出一种多联机***。The fourth purpose of this application is to propose a multi-connection system.

为实现上述目的，本申请第一方面实施例提出了一种多联机***的回油控制方法，所述多联机***包括室外机和多个室内机，所述室外机包括压缩机，所述方法包括以下步骤：在***运行的过程中，每隔第一预设时间获取能够将所述***中的润滑油带回至所述室外机中所需的最低制冷剂流量和所述***的当前制冷剂流量；检测并确定所述当前制冷剂流量小于或等于所述最低制冷剂流量；获取距离上一次回油所述压缩机的总排油量；检测并确定所述总排油量大于最大安全排油量；控制所述***进行回油。To achieve the above object, an embodiment of the first aspect of the present application proposes a method for controlling oil return of a multi-connected system, which includes an outdoor unit and multiple indoor units, the outdoor unit includes a compressor, and the method The method includes the following steps: during the operation of the system, obtaining the minimum refrigerant flow required to bring the lubricating oil in the system to the outdoor unit and the current refrigeration of the system every first preset time. Agent flow rate; detecting and determining that the current refrigerant flow rate is less than or equal to the minimum refrigerant flow rate; obtaining a total oil discharge amount from the compressor that returned to the previous oil return; detecting and determining that the total oil discharge amount is greater than the maximum safety Oil discharge; control the system for oil return.

根据本申请实施例的多联机***的回油控制方法，在***运行的过程中，每隔第一预设时间获取能够将***中的润滑油带回至室外机中所需的最低制冷剂流量和***的当前制冷剂流量，检测并确定当前制冷剂流量小于或等于最低制冷剂流量。获取距离上一次回油压缩机的总排油量，检测并确定总排油量大于最大安全排油量，控制***进行回油。由此，能够保证压缩机不会因排油量大，回油量小而缺油运行，有效提高多联机***的能力能效，且方法简单易行。According to the oil return control method of the multi-online system in the embodiment of the present application, during the system operation, the minimum refrigerant flow rate required to be able to bring the lubricating oil in the system back to the outdoor unit is obtained every first preset time. And the current refrigerant flow rate of the system, detecting and determining that the current refrigerant flow rate is less than or equal to the minimum refrigerant flow rate. Obtain the total oil discharge from the previous oil return compressor, detect and determine that the total oil discharge is greater than the maximum safe oil discharge, and the control system performs oil return. Therefore, it can ensure that the compressor does not run out of oil due to large oil discharge and small oil return, which effectively improves the capacity and energy efficiency of the multi-line system, and the method is simple and easy to implement.

根据本申请的一个实施例，还包括：所述当前制冷剂流量大于所述最低制冷剂流量，检测并确认所述当前制冷剂流量大于所述最低制冷剂流量的持续时间大于第二预设时间；对所述总排油量进行清零，检测并确认距离上一次回油的时间大于第三预设时间；控制所述***进行回油，其中，所述第三预设时间＞所述第二预设时间＞所述第一预设时间。According to an embodiment of the present application, the method further includes: the current refrigerant flow rate is greater than the minimum refrigerant flow rate, and detecting and confirming that the duration of the current refrigerant flow rate is greater than the minimum refrigerant flow rate is greater than a second preset time Clearing the total oil discharge amount, detecting and confirming that the time from the last oil return is greater than a third preset time; controlling the system to perform oil return, wherein the third preset time> the first Two preset times> said first preset time.

根据本申请的一个实施例，上述的多联机***的回油控制方法，还包括：获取所述***的当前运行模式；识别所述当前运行模式为制冷模式，控制所述***进行制冷回油；识别所述当前运行模式为制热模式，控制所述***进行制热回油。According to an embodiment of the present application, the method for controlling oil return of the multi-online system further includes: acquiring a current operation mode of the system; identifying the current operation mode as a cooling mode, and controlling the system to perform cooling and oil return; Identify the current operation mode as a heating mode, and control the system to perform heating and oil return.

根据本申请的一个实施例，获取所述制冷模式下能够将所述***中的润滑油带回至所述室外机中所需的最低制冷剂流量，包括：获取所述***的饱和蒸发温度，根据所述饱和蒸发温度获取所述***的饱和蒸发压力；获取所述***中的润滑油浓度、润滑油密度和冷媒气管的内径；根据所述饱和蒸发压力、所述润滑油浓度、所述润滑油密度和所述冷媒气管的内径，从预设表格中获取所述最低制冷剂流量。According to an embodiment of the present application, obtaining the minimum refrigerant flow rate required to be able to bring the lubricating oil in the system back to the outdoor unit in the cooling mode includes: obtaining a saturated evaporation temperature of the system, Obtain the saturated evaporation pressure of the system according to the saturated evaporation temperature; obtain the lubricant concentration, lubricant density, and the inner diameter of the refrigerant gas pipe in the system; according to the saturated evaporation pressure, the lubricant concentration, and the lubrication The oil density and the inner diameter of the refrigerant gas pipe obtain the minimum refrigerant flow rate from a preset table.

根据本申请的一个实施例，获取所述制热模式下能够将所述***中的润滑油带回至所述室外机中所需的最低制冷剂流量，包括：获取所述***的排气压力；获取***中的润滑油浓度、润滑油密度和冷媒气管的内径；根据所述排气压力、所述润滑油浓度、所述润滑油密度和所述冷媒气管的内径，从预设表格中获取所述最低制冷剂流量。According to an embodiment of the present application, obtaining the minimum refrigerant flow rate required to be able to bring the lubricating oil in the system back to the outdoor unit in the heating mode includes: obtaining an exhaust pressure of the system ; Obtain the lubricating oil concentration, lubricating oil density, and the inner diameter of the refrigerant gas pipe in the system; according to the exhaust pressure, the lubricating oil concentration, the lubricating oil density, and the inner diameter of the refrigerant gas pipe, obtain it from a preset table The minimum refrigerant flow.

根据本申请的一个实施例，所述获取所述***的当前制冷剂流量，包括：获取所述***的排气压力、回气压力和所述压缩机的当前运行频率；根据所述排气压力获取所述***的排气饱和温度；根据所述回气压力获取所述***的回气饱和温度；根据所述排气饱和温度、所述回气饱和温度和所述当前运行频率获取所述当前制冷剂流量。According to an embodiment of the present application, obtaining the current refrigerant flow rate of the system includes: obtaining an exhaust pressure, a return pressure of the system, and a current operating frequency of the compressor; and according to the exhaust pressure Obtain the exhaust saturation temperature of the system; obtain the return saturation temperature of the system according to the return pressure; obtain the current saturation temperature according to the exhaust saturation temperature, the return saturation temperature, and the current operating frequency Refrigerant flow.

根据本申请的一个实施例，通过以下公式获取所述当前制冷剂流量：According to an embodiment of the present application, the current refrigerant flow rate is obtained by the following formula:

G2＝C0+(C1*S)+(C2*D)+(C3*S ²)+(C4*S*D)+(C5*D ²)， G2 = C0 + (C1 * S) + (C2 * D) + (C3 * S ² ) + (C4 * S * D) + (C5 * D ² ),

+(C6*S ³)+(C7*D*S ²)+(C8*S*D ²)+(C9*D ³) + (C6 * S ³ ) + (C7 * D * S ² ) + (C8 * S * D ² ) + (C9 * D ³ )

其中，G2为所述当前制冷剂流量，S为所述回气饱和温度，D为所述排气饱和温度，C0至C9为计算系数，所述C0至C9根据所述当前运行频率获取。Among them, G2 is the current refrigerant flow rate, S is the return gas saturation temperature, D is the exhaust gas saturation temperature, C0 to C9 are calculation coefficients, and C0 to C9 are obtained according to the current operating frequency.

为实现上述目的，本申请第二方面实施例提出了一种非临时性计算机可读存储介质，其上存储有计算机程序，该程序被处理器执行时实现上述的冷水机组的回油控制方法。In order to achieve the above object, the embodiment of the second aspect of the present application proposes a non-transitory computer-readable storage medium on which a computer program is stored, which is executed by a processor to implement the above-mentioned oil return control method of a chiller unit.

根据本申请实施例的非临时性计算机可读存储介质，通过执行上述的多联机***的回油控制方法，能够保证压缩机不会因排油量大，回油量小而缺油运行，有效提高多联机***的能力能效，且方法简单易行。According to the non-transitory computer-readable storage medium of the embodiment of the present application, by implementing the above-mentioned multi-line system oil return control method, it is possible to ensure that the compressor does not run out of oil due to large oil discharge and small oil return, which is effective Improve the capacity and energy efficiency of multi-connected systems, and the method is simple and easy to implement.

为实现上述目的，本申请第三方面实施例提出了一种多联机***的回油控制装置，所述多联机***包括室外机和多个室内机，所述室外机包括压缩机，所述装置包括：第一获取模块，用于在***运行的过程中，每隔第一预设时间获取能够将所述***中的润滑油带回至所述室外机中所需的最低制冷剂流量；第二获取模块，用于在所述***运行的过程中，每隔所述第一预设时间获取所述***的当前制冷剂流量；控制模块，用于检测并确定所述当前制冷剂流量小于或等于所述最低制冷剂流量，获取距离上一次回油所述压缩机的总排油量，检测并确定所述总排油量大于最大安全排油量，控制所述***进行回油。In order to achieve the above object, an embodiment of the third aspect of the present application proposes an oil return control device of a multiple online system, the multiple online system includes an outdoor unit and a plurality of indoor units, the outdoor unit includes a compressor, and the device The method includes: a first obtaining module, configured to obtain, at a first preset time, the minimum refrigerant flow required to bring the lubricating oil in the system back to the outdoor unit during the system operation; Two acquisition modules are used to acquire the current refrigerant flow of the system every first preset time during the operation of the system; a control module is used to detect and determine that the current refrigerant flow is less than or Equal to the minimum refrigerant flow rate, obtain the total oil discharge amount from the compressor that returned oil last time, detect and determine that the total oil discharge amount is greater than the maximum safe oil discharge amount, and control the system to return oil.

根据本申请实施例的多联机***的回油控制装置，通过第一获取模块在***运行的过程中，每隔第一预设时间获取能够将***中的润滑油带回至室外机中所需的最低制冷剂流量，并通过第二获取模块在***运行的过程中，每隔第一预设时间获取***的当前制冷剂流量，并通过控制模块检测并确定当前制冷剂流量小于或等于最低制冷剂流量，获取距离上一次回油压缩机的总排油量，检测并确定总排油量大于最大安全排油量控制***进行回油。由此，能够保证压缩机不会因排油量大，回油量小而缺油运行，有效提高多联机***的能力能效，且方法简单易行。According to the oil return control device of the multi-online system according to the embodiment of the present application, during the system running process, the first acquisition module acquires the lubricant required to be able to bring the lubricating oil in the system back to the outdoor unit every first preset time. The minimum refrigerant flow rate, and obtain the current refrigerant flow rate of the system every first preset time during the system operation through the second acquisition module, and detect and determine that the current refrigerant flow rate is less than or equal to the minimum refrigeration rate through the control module. Agent flow rate to obtain the total oil discharge from the previous oil return compressor, and detect and determine that the total oil discharge is greater than the maximum safe oil discharge control system for oil return. Therefore, it can ensure that the compressor does not run out of oil due to large oil discharge and small oil return, which effectively improves the capacity and energy efficiency of the multi-line system, and the method is simple and easy to implement.

根据本申请的一个实施例，所述控制模块还具体用于，所述当前制冷剂流量大于所述最低制冷剂流量，检测并确定所述当前制冷剂流量大于所述最低制冷剂流量的持续时间大于第二预设时间；对所述总排油量进行清零，检测并确定距离上一次回油的时间大于第三预设时间，控制所述***进行回油，其中，所述第三预设时间＞所述第二预设时间＞所述第一预设时间。According to an embodiment of the present application, the control module is further specifically configured to detect that the current refrigerant flow rate is greater than the minimum refrigerant flow rate and duration of the current refrigerant flow rate is greater than the minimum refrigerant flow rate. Greater than a second preset time; clearing the total oil discharge amount, detecting and determining that the time from the last oil return is greater than a third preset time, and controlling the system to perform oil return, wherein the third Set time> the second preset time> the first preset time.

根据本申请的一个实施例，上述的多联机***的回油控制装置，还包括：第三获取模块，用于获取所述***的当前运行模式；所述控制模块，还用于识别所述当前运行模式为制冷模式，控制所述***进行制冷回油，识别所述当前运行模式为制热模式，控制所述***进行制热回油。According to an embodiment of the present application, the oil return control device of the multi-online system further includes: a third acquisition module, configured to acquire a current operating mode of the system; and the control module, further configured to identify the current operation mode of the system. The operating mode is a cooling mode, the system is controlled to perform cooling and oil return, the current operating mode is identified as a heating mode, and the system is controlled to perform heating and oil return.

根据本申请的一个实施例，识别所述当前运行模式为所述制冷模式，所述第一获取模块具体用于：获取所述***的饱和蒸发温度，根据所述饱和蒸发温度获取所述***的饱和蒸发压力；获取所述***中的润滑油浓度、润滑油密度和冷媒气管的内径；根据所述饱和蒸发压力、所述润滑油浓度、所述润滑油密度和所述冷媒气管的内径，从预设表格中获取所述最低制冷剂流量。According to an embodiment of the present application, the current operating mode is identified as the cooling mode, and the first obtaining module is specifically configured to obtain a saturation evaporation temperature of the system, and obtain the system's saturation evaporation temperature according to the saturation evaporation temperature. Saturated evaporation pressure; obtaining the lubricating oil concentration, lubricating oil density, and the inner diameter of the refrigerant gas pipe in the system; according to the saturated evaporation pressure, the lubricating oil concentration, the lubricating oil density, and the inner diameter of the refrigerant gas pipe, The preset refrigerant flow is obtained in a preset table.

根据本申请的一个实施例，识别所述当前运行模式为所述制热模式，所述第一获取模块具体用于：获取所述***的排气压力；获取***中的润滑油浓度、润滑油密度和冷媒气管的内径；根据所述排气压力、所述润滑油浓度、所述润滑油密度和所述冷媒气管的内径，从预设表格中获取所述最低制冷剂流量。According to an embodiment of the present application, the current operation mode is identified as the heating mode, and the first acquisition module is specifically configured to: acquire an exhaust pressure of the system; acquire a lubricating oil concentration and a lubricating oil in the system; The density and the inner diameter of the refrigerant gas pipe; the minimum refrigerant flow rate is obtained from a preset table according to the exhaust pressure, the lubricating oil concentration, the lubricating oil density, and the inner diameter of the refrigerant gas pipe.

根据本申请的一个实施例，所述第二获取模块具体用于：获取所述***的排气压力、回气压力和所述压缩机的当前运行频率；根据所述排气压力获取所述***的排气饱和温度；根据所述回气压力获取所述***的回气饱和温度；根据所述排气饱和温度、所述回气饱和温度和所述当前运行频率获取所述当前制冷剂流量。According to an embodiment of the present application, the second acquisition module is specifically configured to: acquire an exhaust pressure, a return pressure of the system, and a current operating frequency of the compressor; and acquire the system according to the exhaust pressure Obtain the exhaust gas saturation temperature of the system according to the return gas pressure; obtain the current refrigerant flow rate according to the exhaust gas saturation temperature, the return gas saturation temperature, and the current operating frequency.

根据本申请的一个实施例，所述第二获取模块通过以下公式获取所述当前制冷剂流量：According to an embodiment of the present application, the second obtaining module obtains the current refrigerant flow rate by the following formula:

为实现上述目的，本申请第四方面实施例提出了一种多联机***，其包括上述的多联机***的回油控制装置。In order to achieve the above object, an embodiment of the fourth aspect of the present application proposes a multi-online system, which includes the oil return control device of the multi-online system.

根据本申请实施例的多联机***，通过上述的多联机***的回油控制装置，能够保证压缩机不会因排油量大，回油量小而缺油运行，有效提高多联机***的能力能效，且方法简单易行。According to the multi-connected system of the embodiment of the present application, the oil return control device of the multi-connected system can ensure that the compressor does not run out of oil due to large oil discharge and small oil return, which effectively improves the capacity of the multi-connected system. Energy efficient and easy to implement.

本申请附加的方面和优点将在下面的描述中部分给出，部分将从下面的描述中变得明显，或通过本申请的实践了解到。Additional aspects and advantages of the present application will be given in part in the following description, part of which will become apparent from the following description, or be learned through practice of the present application.

附图说明BRIEF DESCRIPTION OF THE DRAWINGS

图1是根据本申请实施例的多联机***的回油控制方法的流程图。FIG. 1 is a flowchart of a method for controlling oil return of a multi-online system according to an embodiment of the present application.

图2是根据本申请一个实施例的制冷模式下最低制冷剂流量的获取流程图；2 is a flowchart of obtaining a minimum refrigerant flow rate in a cooling mode according to an embodiment of the present application;

图3是根据本申请一个实施例的制热模式下最低制冷剂流量的获取流程图；3 is a flowchart of obtaining a minimum refrigerant flow rate in a heating mode according to an embodiment of the present application;

图4是根据本申请一个实施例的制冷模式下多联机***的回油控制方法的流程图；4 is a flowchart of a method for controlling oil return of a multi-online system in a cooling mode according to an embodiment of the present application;

图5是根据本申请一个实施例的制热模式下多联机***的回油控制方法的流程图；5 is a flowchart of a method for controlling oil return of a multi-online system in a heating mode according to an embodiment of the present application;

图6是根据本申请实施例的多联机***的回油控制装置的方框示意图。FIG. 6 is a block diagram of an oil return control device of a multi-online system according to an embodiment of the present application.

具体实施方式detailed description

下面详细描述本申请的实施例，实施例的示例在附图中示出，其中自始至终相同或类似的标号表示相同或类似的元件或具有相同或类似功能的元件。下面通过参考附图描述的实施例是示例性的，旨在用于解释本申请，而不能理解为对本申请的限制。The embodiments of the present application are described in detail below. Examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals indicate the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are exemplary, and are intended to explain the present application, and should not be construed as limiting the present application.

下面参考附图描述根据本申请实施例提出的多联机***的回油控制方法、非临时性计算机可读存储介质、多联机***的回油控制装置和多联机***。The following describes an oil return control method, a non-transitory computer-readable storage medium, an oil return control device for a multiple online system, and a multiple online system according to an embodiment of the present application with reference to the drawings.

在本申请的实施例中，多联机***可包括室外机和多个室内机，室外机包括压缩机。In the embodiment of the present application, the multi-connection system may include an outdoor unit and a plurality of indoor units, and the outdoor unit includes a compressor.

如图1所示，本申请实施例的多联机***的回油控制方法可包括以下步骤：As shown in FIG. 1, the oil return control method of the multi-online system in the embodiment of the present application may include the following steps:

S1，在***运行的过程中，每隔第一预设时间获取能够将***中的润滑油带回至室外机中所需的最低制冷剂流量和***的当前制冷剂流量。其中，第一预设时间可根据实际情况进行标定。S1. During the operation of the system, the minimum refrigerant flow rate required to bring the lubricating oil in the system to the outdoor unit and the current refrigerant flow rate of the system are obtained every first preset time. The first preset time can be calibrated according to the actual situation.

具体而言，可以在***运行过程中，根据***的运行参数获取将***中的润滑油带回至室外机中所需的最低制冷剂流量和***的当前制冷剂流量。Specifically, during the system operation, the minimum refrigerant flow required to bring the lubricating oil in the system back to the outdoor unit and the current refrigerant flow of the system can be obtained according to the operating parameters of the system.

根据本申请的一个实施例，如图2所示，获取制冷模式下能够将***中的润滑油带回至室外机中所需的最低制冷剂流量，包括：According to an embodiment of the present application, as shown in FIG. 2, obtaining the minimum refrigerant flow required to be able to bring the lubricating oil in the system back to the outdoor unit in the cooling mode includes:

S201，获取***的饱和蒸发温度，根据饱和蒸发温度获取***的饱和蒸发压力。S201: Obtain a saturated evaporation temperature of the system, and obtain a saturated evaporation pressure of the system according to the saturated evaporation temperature.

具体而言，在***以制冷模式运行的过程中，可分别获取多个室内机中处于运行状态的每个室内机的室内换热器管温，以获得多个室内换热器管温，然后对多个室内换热器管温求平均值，以获得***的饱和蒸发温度。例如，假设多个室内机中有10个室内机处于运行状态，并且其中5个室内机的室内换热器管温为7℃,5个室内机的室内换热器管温为8℃，那么获得的***的饱和蒸发温度为(5*7+8*5)/10＝7.5。根据饱和蒸发温度，通过查询饱和蒸发温度与饱和蒸发压力之间的关系表，获得***的饱和蒸发压力。Specifically, during the operation of the system in the cooling mode, the indoor heat exchanger tube temperatures of each indoor unit in a running state among multiple indoor units may be obtained separately to obtain multiple indoor heat exchanger tube temperatures, and then Average the temperature of multiple indoor heat exchanger tubes to obtain the saturated evaporation temperature of the system. For example, assuming that 10 indoor units of multiple indoor units are running, and the indoor heat exchanger tube temperature of 5 indoor units is 7 ° C, and the indoor heat exchanger tube temperature of 5 indoor units is 8 ° C, then The saturation evaporation temperature of the obtained system was (5 * 7 + 8 * 5) /10=7.5. According to the saturation evaporation temperature, the system's saturation evaporation pressure is obtained by querying the relationship table between the saturation evaporation temperature and the saturation evaporation pressure.

S202，获取***中的润滑油浓度、润滑油密度和冷媒气管的内径。S202: Obtain the lubricant concentration, the lubricant density, and the inner diameter of the refrigerant gas pipe in the system.

S203，根据饱和蒸发压力、润滑油浓度、润滑油密度和冷媒气管的内径，从预设表格中获取最低制冷剂流量。S203. Obtain the minimum refrigerant flow rate from a preset table according to the saturated evaporation pressure, the lubricating oil concentration, the lubricating oil density, and the inner diameter of the refrigerant gas pipe.

具体地，在***安装完成后，可将润滑油浓度、润滑油密度以及冷媒气管的内径预先存储在***中。在***以制冷模式运行过程中，获取***的饱和蒸发温度，根据饱和蒸发温度获取***的饱和蒸发压力，然后根据饱和蒸发压力、润滑油浓度、润滑油密度和冷媒气管的内径大小，从预设表格中获取最低制冷剂流量(即，冷媒气管中的最低气态循环量)。Specifically, after the system is installed, the lubricating oil concentration, the lubricating oil density, and the inner diameter of the refrigerant gas pipe may be stored in the system in advance. When the system is operating in the cooling mode, the saturation evaporation temperature of the system is obtained, the saturation evaporation pressure of the system is obtained according to the saturation evaporation temperature, and then the preset value Get the minimum refrigerant flow (ie, the minimum gaseous circulation in the refrigerant gas pipe) in the table.

其中，预设表格可预先通过大量实验测试获得。举例而言，表1为制冷模式下饱和蒸发压力为1200MPa时，不同管径下的最低制冷剂流量。The preset form can be obtained through a large number of experimental tests in advance. For example, Table 1 shows the minimum refrigerant flow rate under different tube diameters when the saturation evaporation pressure is 1200 MPa in the cooling mode.

表1Table 1

如表1所示，在制冷模式下，当获得的***的饱和蒸发温度为16.3℃时，对应的***的饱和蒸发压力为1200MPa，如果此时润滑油浓度为1.0％，润滑油密度为930.0kg/m ³、冷媒气管的内径为32.3cm，那么当前将***中的润滑油带回至室外机中所需的最低制冷剂流量为392.13kg/h。 As shown in Table 1, in the cooling mode, when the saturation evaporation temperature of the obtained system is 16.3 ° C, the saturation evaporation pressure of the corresponding system is 1200 MPa. If the lubricant concentration is 1.0% at this time, the lubricant density is 930.0kg / m ³ , the inner diameter of the refrigerant gas pipe is 32.3cm, then the minimum refrigerant flow required to bring the lubricating oil in the system back to the outdoor unit is 392.13kg / h.

根据本申请的一个实施例，如图3所示，获取制热模式下能够将***中的润滑油带回至室外机中所需的最低制冷剂流量，包括：According to an embodiment of the present application, as shown in FIG. 3, obtaining the minimum refrigerant flow required to be able to bring the lubricating oil in the system back to the outdoor unit in the heating mode includes:

S301，获取***的排气压力。S301. Obtain the exhaust pressure of the system.

具体地，可通过获取压缩机的排气口处的压力以获得***的排气压力。Specifically, the exhaust pressure of the system can be obtained by obtaining the pressure at the exhaust port of the compressor.

需要说明的是，制热模式下，***的排气压力也为***的冷凝压力，可直接通过设置在压缩机的排气口处的压力传感器获取，也可以通过设置在压缩机的排气口处的温度传感器获得排气温度，即***的冷凝温度，然后根据冷凝温度获得***的冷凝压力，即排气压力。It should be noted that, in the heating mode, the exhaust pressure of the system is also the condensation pressure of the system, which can be obtained directly through a pressure sensor provided at the exhaust port of the compressor, or can be obtained through the exhaust port of the compressor. The temperature sensor at the place obtains the exhaust temperature, that is, the condensation temperature of the system, and then obtains the condensation pressure of the system, that is, the exhaust pressure according to the condensation temperature.

S302，获取***中的润滑油浓度、润滑油密度和冷媒气管的内径。S302. Obtain the lubricating oil concentration, the lubricating oil density, and the inner diameter of the refrigerant gas pipe in the system.

S303，根据排气压力、润滑油浓度、润滑油密度和冷媒气管的内径，从预设表格中获取最低制冷剂流量。S303. Obtain the minimum refrigerant flow rate from the preset table according to the exhaust pressure, the lubricant concentration, the lubricant density, and the inner diameter of the refrigerant gas pipe.

具体地，在***安装完成后，可将润滑油浓度、润滑油密度以及冷媒气管的内径预先存储在***中。在***以制热模式运行过程中，获取***的排气压力，然后根据排气压力、润滑油浓度、润滑油密度和冷媒气管的内径大小，从预设表格中获取最低制冷剂流量(即，冷媒气管中的最低气态循环量)。Specifically, after the system is installed, the lubricating oil concentration, the lubricating oil density, and the inner diameter of the refrigerant gas pipe may be stored in the system in advance. When the system is operating in heating mode, the exhaust pressure of the system is obtained, and then the minimum refrigerant flow rate is obtained from a preset table (that is, according to the exhaust pressure, lubricating oil concentration, lubricating oil density, and the inner diameter of the refrigerant air pipe (i.e., The minimum gaseous circulation in the refrigerant gas pipe).

其中，预设表格可预先通过大量实验测试获得。举例而言，表2为制热模式下排气压力为2200MPa时，不同管径下的最低制冷剂流量。The preset form can be obtained through a large number of experimental tests in advance. For example, Table 2 shows the minimum refrigerant flow rate under different pipe diameters when the exhaust pressure is 2200 MPa in heating mode.

表2Table 2

如表2所示，在制热模式下，当获得的***的排气压力为2200MPa，如果此时润滑油浓度为1.0％，润滑油密度为930.0kg/m ³、冷媒气管的内径为32.3cm，那么当前将***中的润滑油带回至室外机中所需的最低制冷剂流量为392.13kg/h。 As shown in Table 2, in the heating mode, when the exhaust pressure of the obtained system is 2200 MPa, if the lubricant concentration is 1.0%, the lubricant density is 930.0 kg / m ³ , and the inner diameter of the refrigerant gas pipe is 32.3 cm , Then the minimum refrigerant flow required to bring the lubricant in the system back to the outdoor unit is 392.13kg / h.

根据本申请的一个实施例，获取***的当前制冷剂流量，包括：获取***的排气压力、回气压力和压缩机的当前运行频率；根据排气压力获取***的排气饱和温度；根据回气压力获取***的回气饱和温度；根据排气饱和温度、回气饱和温度和当前运行频率获取当前制冷剂流量。According to an embodiment of the present application, obtaining the current refrigerant flow rate of the system includes: obtaining the exhaust pressure, the return pressure of the system, and the current operating frequency of the compressor; obtaining the exhaust saturation temperature of the system according to the exhaust pressure; The air pressure obtains the return air saturation temperature of the system; obtains the current refrigerant flow rate according to the exhaust saturation temperature, the return air saturation temperature, and the current operating frequency.

根据本申请的一个实施例，可通过下述公式(1)获取当前制冷剂流量：According to an embodiment of the present application, the current refrigerant flow rate can be obtained by the following formula (1):

其中，G2为当前制冷剂流量，S为回气饱和温度，D为排气饱和温度，C0至C9为计算系数，C0至C9根据当前运行频率获取。Among them, G2 is the current refrigerant flow rate, S is the return gas saturation temperature, D is the exhaust gas saturation temperature, C0 to C9 are calculation coefficients, and C0 to C9 are obtained according to the current operating frequency.

具体地，在***运行的过程中，可先根据压缩机的回气压力和排气压力，计算出回气饱和温度和排气饱和温度，再根据压缩机的运行频率，利用压缩机厂商提供的十系数，计算出当前制冷剂流量，即实际气态循环量。Specifically, during the operation of the system, the return air saturation temperature and the exhaust gas saturation temperature can be calculated according to the return pressure and the exhaust pressure of the compressor, and then the compressor manufacturer's Ten coefficients to calculate the current refrigerant flow, that is, the actual gaseous circulation.

例如，表3为某压缩机厂商提供的十系数。For example, Table 3 is a ten-factor provided by a compressor manufacturer.

表3table 3

参数序号Parameter number	能力CCapability C	一次侧功率PPrimary power P	一次侧电流APrimary current A	质量流量MMass flow M
C0C0	157083.7038157083.7038	-147.4029839-147.4029839	5.22452E-055.22452E-05	506.1576401506.1576401
C1C1	5461.2439945461.243994	-15.66866598-15.66866598	3.17939E-053.17939E-05	20.2376534320.23765343
C2C2	-0.070791694-0.070791694	290.0853125290.0853125	0.328667520.32866752	10.8882309410.88823094
C3C3	56.5062781556.50627815	-0.598613169-0.598613169	0.0014387980.001438798	0.3361761280.336176128
C4C4	-0.189212999-0.189212999	0.8554423110.855442311	0.0008555270.000855527	0.2159245620.215924562
C5C5	-19.38408202-19.38408202	0.6181208740.618120874	0.0079609090.007960909	-0.159218374-0.159218374
C6C6	0.0163188660.016318866	-0.000650971-0.000650971	1.89498E-051.89498E-05	-0.00096547-0.00096547
C7C7	-0.025955152-0.025955152	-0.004744646-0.004744646	-5.70037E-05-5.70037E-05	-0.000151881-0.000151881
C8C8	-0.452236172-0.452236172	0.0031243160.003124316	-1.11086E-05-1.11086E-05	-0.002222256-0.002222256
C9C9	0.0682651150.068265115	-0.00785332-0.00785332	-5.86867E-05-5.86867E-05	0.0006407920.000640792

需要说明的是，上述公式(1)中的计算系数C0至C9分别为表3中能力C所对应的值。It should be noted that the calculation coefficients C0 to C9 in the above formula (1) are the values corresponding to the capacity C in Table 3.

在实际应用中，不同的压缩机运行频率对应不同的十系数，通常压缩机厂商会提供多个运行频率下的十系数，如，30Hz、60Hz、75Hz和90Hz等运行频率下的十系数，此时可先根据不同运行频率下的十系数，采用插值算法获得当前运行频率下的十系数，然后根据当前运行频率下的十系数，通过上述公式(1)计算获得***的当前制冷剂流量。例如，假设压缩机的当前运行频率为70Hz，那么根据60Hz和75Hz运行频率下的十系数采用插值算法可获得70Hz运行频率下的十系数，其中，十系数中的能力C所对应的值分别为该运行频率下的计算系数C0至C9，然后根据计算系数C0至C9，以及获取的回气饱和温度和排气饱和温度，通过上述公式(1)计算获得***的当前制冷剂流量。In practical applications, different compressor operating frequencies correspond to different ten coefficients. Usually compressor manufacturers provide ten coefficients at multiple operating frequencies, such as ten coefficients at operating frequencies such as 30Hz, 60Hz, 75Hz, and 90Hz. At this time, the ten coefficients at the current operating frequency can be obtained by using an interpolation algorithm according to the ten coefficients at different operating frequencies, and then the current refrigerant flow rate of the system can be obtained by the above formula (1) according to the ten coefficients at the current operating frequency. For example, assuming that the current operating frequency of the compressor is 70Hz, then the interpolation algorithm can be used to obtain the ten coefficients at the operating frequency of 70Hz based on the ten coefficients at the operating frequencies of 60Hz and 75Hz, where the values of the capacity C in the ten coefficients are respectively The calculation coefficients C0 to C9 at this operating frequency, and then according to the calculation coefficients C0 to C9, and the obtained return gas saturation temperature and exhaust gas saturation temperature, the current refrigerant flow rate of the system is calculated by the above formula (1).

当然，也可以先根据60Hz运行频率下的十系数、获取的回气饱和温度和排气饱和温度，通过上述公式(1)计算获得***在60Hz运行频率下的制冷剂流量，同时根据75Hz运行频率下的十系数、获取的回气饱和温度和排气饱和温度，通过上述公式(1)计算获得***在75Hz运行频率下的制冷剂流量，然后，再采用插值算法计算出70Hz运行频率下***的制冷剂流量，即***的当前制冷剂流量。可以理解的是，该方式相较于前一种方式，计算量大大减少，所以优选地，采用该方式。Of course, you can also first calculate the refrigerant flow rate of the system at the 60Hz operating frequency based on the ten coefficients at the 60Hz operating frequency, the obtained return gas saturation temperature, and the exhaust saturation temperature. Under the ten coefficients, the obtained return gas saturation temperature and the exhaust gas saturation temperature, the refrigerant flow rate of the system at the operating frequency of 75 Hz is obtained by the above formula (1), and then the interpolation Refrigerant flow, which is the current refrigerant flow of the system. It can be understood that, compared with the former method, this method has a greatly reduced calculation amount, so it is preferable to adopt this method.

需要说明的是，制冷模式和制热模式下，当前制冷剂流量的获取方式相同。It should be noted that, in the cooling mode and the heating mode, the current refrigerant flow acquisition method is the same.

S2，检测并确定当前制冷剂流量小于或等于最低制冷剂流量。S2. Detect and determine that the current refrigerant flow rate is less than or equal to the minimum refrigerant flow rate.

S3，获取距离上一次回油压缩机的总排油量。S3. Obtain the total oil discharge amount from the previous oil return compressor.

具体地，压缩机每次运行都会排油，而压缩机的排油率(即，油吐出率)是可知的，所以可以根据压缩机的排油率计算获得油压缩机的总排油量。Specifically, the compressor discharges oil every time the compressor is run, and the oil discharge rate of the compressor (that is, the oil discharge rate) is known, so the total oil discharge of the oil compressor can be calculated based on the oil discharge rate of the compressor.

举例而言，压缩机的排油率可由压缩机厂商提供，如表4所示。For example, the discharge rate of the compressor can be provided by the compressor manufacturer, as shown in Table 4.

表4Table 4

最低油量Minimum oil	350ml350ml
出厂油量Ex-factory oil quantity	500ml500ml
油吐出量安全计算Safety calculation of oil discharge	470cm ³ 470cm ³
压缩机排气量Compressor displacement	36cm ³/rev 36cm ³ / rev
油稀释度界限Oil dilution limit	0.40.4
最低转速Minimum speed	30rps30rps
最高转速Speed	90rps90rps
30rps油吐出率(％)30rps oil discharge rate (%)	0.41％0.41%
60rps油吐出率(％)60rps oil discharge rate (%)	0.73％0.73%
90rps油吐出率(％)90rps oil discharge rate (%)	1.56％1.56%
120rps油吐出率(％)120rps oil discharge rate (%)	2.00％2.00%

其中，表4给出了不同转速下的油吐出率，由于转速与运行频率呈比例关系，所以根据不同转速下的油吐出率，可获得不同运行频率下的油吐出率，进而通过插值算法可获得当前运行频率下的油吐出率，然后根据当前运行频率下的油吐出率、当前制冷剂流量、压缩机的运行时间和润滑油密度可获得压缩机的总排油量。例如，压缩机的总排油量＝当前运行频率下的油吐出率*当前制冷剂流量*压缩机的运行时间/润滑油密度。Among them, Table 4 shows the oil discharge rates at different speeds. Because the speed is proportional to the operating frequency, the oil discharge rates at different operating frequencies can be obtained according to the oil discharge rates at different speeds. Obtain the oil discharge rate at the current operating frequency, and then obtain the total oil discharge of the compressor according to the oil discharge rate at the current operating frequency, the current refrigerant flow rate, the operating time of the compressor, and the lubricant density. For example, the total oil displacement of the compressor = the oil discharge rate at the current operating frequency * the current refrigerant flow rate * the compressor's operating time / lubricant density.

需要说明的是，对于一些具有油分离器的***来说，还根据油分离器的分离效率来进一步获得压缩机的总排油量，例如，压缩机的总排油量＝当前运行频率下的油吐出率*当前制冷剂流量*(1-油分离器的分离效率)*压缩机的运行时间/润滑油密度，其中，油分离器的分离效率一般为90％。It should be noted that, for some systems with an oil separator, the total oil discharge of the compressor is further obtained according to the separation efficiency of the oil separator, for example, the total oil discharge of the compressor = the current operating frequency Oil discharge rate * current refrigerant flow rate * (1-separation efficiency of oil separator) * compressor operating time / lubricating oil density, wherein the separation efficiency of the oil separator is generally 90%.

S4，检测并确定总排油量大于最大安全排油量。S4. Detect and determine that the total oil discharge is greater than the maximum safe oil discharge.

其中，最大安全排油量可由压缩机厂商提供的数据获得，如表4所示，压缩机的最大安全排油量为470ml。Among them, the maximum safe oil discharge can be obtained from the data provided by the compressor manufacturer. As shown in Table 4, the maximum safe oil discharge of the compressor is 470ml.

S5，控制***进行回油。S5, the control system performs oil return.

具体而言，在***运行过程中，实时获取将***中的润滑油带回至室外机中所需的最低制冷剂流量和***的当前制冷剂流量，并判断当前制冷剂流量是否小于或等于最低制冷剂流量。如果是，则说明当前制冷剂流量过低，润滑油无法正常回到室外机，此时计算出压缩机的累计排油量即总排油量，并判断总排油量是否大于最大安全排油量，如果是，则说明当前排油量大，容易造成压缩机缺油运行，所以此时控制***进行回油运行，以保证压缩机不会出现缺油运行损坏的现象。由此，可以保证压缩机不会因排油量大，回油量小而缺油运行，有效提高多联机***的能力能效，且方法简单易行。Specifically, during the operation of the system, the minimum refrigerant flow required to bring the lubricating oil in the system back to the outdoor unit and the current refrigerant flow of the system are obtained in real time, and whether the current refrigerant flow is less than or equal to the minimum Refrigerant flow. If it is, the current refrigerant flow is too low, and the lubricating oil cannot return to the outdoor unit normally. At this time, the cumulative oil discharge of the compressor is calculated as the total oil discharge, and whether the total oil discharge is greater than the maximum safe oil discharge If it is, it means that the current oil discharge volume is large and it is easy to cause the compressor to run out of oil. Therefore, the control system performs oil return operation at this time to ensure that the compressor will not run out of oil. Therefore, it can be ensured that the compressor does not run out of oil due to large oil discharge and small oil return, which effectively improves the capacity and energy efficiency of the multi-line system, and the method is simple and easy to implement.

进一步地，根据本申请的一个实施例，还包括：当前制冷剂流量大于最低制冷剂流量，检测并确认当前制冷剂流量大于最低制冷剂流量的持续时间是否第二预设时间；对总排油量进行清零，检测并确认距离上一次回油的时间大于第三预设时间；控制***进行回油其中，第三预设时间＞第二预设时间＞第一预设时间，第一预设时间、第二预设时间和第三预设时间可根据实际情况进行标定。Further, according to an embodiment of the present application, the method further includes: detecting and confirming whether a duration in which the current refrigerant flow rate is greater than the minimum refrigerant flow rate is the second preset time; The amount is cleared, and the time from the last oil return is detected and confirmed to be greater than the third preset time. The control system performs oil return. The third preset time is the second preset time. The first preset time is the first preset time. The set time, the second preset time, and the third preset time can be calibrated according to the actual situation.

具体而言，如果当前制冷剂流量大于最低制冷剂流量且持续第二预设时间，则说明当前制冷剂流量充足，可以使得润滑油正常回到室外机，此时无需进行专门的回油控制，当***运行的时间距离上一次回油的时间大于第三预设时间时，再控制***进行回油。由此，在***制冷剂流量充足的情况下，尽可能减少专门回油的过程，保证室内的舒适性。Specifically, if the current refrigerant flow rate is greater than the minimum refrigerant flow rate and continues for a second preset time, it means that the current refrigerant flow rate is sufficient to allow the lubricating oil to return to the outdoor unit normally, and no special oil return control is required at this time. When the time that the system is running is longer than the third preset time after the last oil return time, the control system performs oil return. Therefore, when the system refrigerant flow is sufficient, the process of special oil return is reduced as much as possible to ensure indoor comfort.

根据本申请的一个实施例，上述的多联机***的回油控制方法，还包括：获取***的当前运行模式；识别当前运行模式为制冷模式，控制***进行制冷回油；识别当前运行模式为制热模式，控制***进行制热回油。According to an embodiment of the present application, the above-mentioned multi-line system oil return control method further includes: obtaining a current operation mode of the system; identifying the current operation mode as a cooling mode, and controlling the system to perform cooling and oil return; identifying the current operation mode as a system In thermal mode, the control system performs heating and oil return.

具体而言，如果***当前处于制冷模式，则直接进行制冷回油，而如果***当前处于制热模式，则直接进行制热回油，具体可采用现有技术实现，从而有效避免回油过程对室内舒适性的影响。例如，在制热模式下，当需要进行回油时，切换至制冷模式，从而导致室内温度降低，影响室内舒适性。Specifically, if the system is currently in the cooling mode, the cooling and oil return is performed directly, and if the system is currently in the heating mode, the heating and oil return is directly performed, which can be implemented by using the existing technology, thereby effectively avoiding the oil return process. Impact of indoor comfort. For example, in the heating mode, when oil return is required, switching to the cooling mode causes the indoor temperature to decrease and affects indoor comfort.

进一步地，为使本领域技术人员能够更清楚的了解本申请。图4是根据本申请一个实施例的制冷模式下多联机***的回油控制方法的流程图，如图4所示，该多联机***的回油控制方法可包括以下步骤：Further, in order to enable those skilled in the art to understand the application more clearly. FIG. 4 is a flowchart of a method for controlling oil return of a multi-line system in a cooling mode according to an embodiment of the present application. As shown in FIG. 4, the method of controlling oil return of the multi-line system may include the following steps:

S401，多联机***在制冷模式下运行。S401, the multi-connection system operates in a cooling mode.

S402，采集室内机的室内换热器管温。S402: Collect the indoor heat exchanger tube temperature of the indoor unit.

S403，计算出最低制冷剂流量G1。S403. Calculate the minimum refrigerant flow rate G1.

S404，采集回气压力Pe和回气温度Te。S404: Collect the return pressure Pe and the return temperature Te.

S405，计算出当前制冷剂流量G2。S405: Calculate the current refrigerant flow rate G2.

S406，判断当前制冷剂流量G2是否大于最低制冷剂流量G1，如果是，则执行步骤S407，如果否，则执行步骤S411。S406: Determine whether the current refrigerant flow rate G2 is greater than the minimum refrigerant flow rate G1, and if yes, execute step S407; if not, execute step S411.

S407，前制冷剂流量G2大于最低制冷剂流量G1的持续时间是否大于t1，如果是，则执行步骤S408，否则，执行步骤S402S407: Is the duration of the front refrigerant flow G2 greater than the minimum refrigerant flow G1 greater than t1? If yes, go to step S408; otherwise, go to step S402

S408，总排油量进行清零。S408: The total oil discharge amount is cleared.

S409，判断距离上一次回油的时间是否大于t2，如果是，则执行步骤S410，否则执行步骤S402。S409: Determine whether the time from the last oil return is greater than t2, and if yes, perform step S410; otherwise, perform step S402.

S410，运行制冷回油。S410: Run refrigeration and return oil.

S411，获取距离上一次回油压缩机的总排油量。S411. Obtain the total oil discharge amount from the previous oil return compressor.

S412，总排油量是否大于最大安全排油量，如果是，则执行步骤S410，否则，执行步骤S402。S412: Whether the total oil discharge amount is greater than the maximum safe oil discharge amount, and if yes, perform step S410; otherwise, perform step S402.

图5是根据本申请一个实施例的制热模式下多联机***的回油控制方法的流程图，如图5所示，该多联机***的回油控制方法可包括以下步骤：FIG. 5 is a flowchart of a method for controlling oil return in a multi-online system in a heating mode according to an embodiment of the present application. As shown in FIG. 5, the method for controlling oil return in a multi-online system may include the following steps:

S501，多联机***在制热模式下运行。S501, the multi-line system is operated in a heating mode.

S502，采集排气压力Pc。S502: Collect exhaust pressure Pc.

S503，计算出最低制冷剂流量G1。S503. Calculate the minimum refrigerant flow rate G1.

S504，采集回气压力Pe和回气温度Te。S504. Collect the return pressure Pe and the return temperature Te.

S505，计算出当前制冷剂流量G2。S505: Calculate the current refrigerant flow rate G2.

S506，判断当前制冷剂流量G2是否大于最低制冷剂流量G1，如果是，则执行步骤S507，如果否，则执行步骤S511。S506: Determine whether the current refrigerant flow rate G2 is greater than the minimum refrigerant flow rate G1, and if yes, execute step S507; if no, execute step S511.

S507，前制冷剂流量G2大于最低制冷剂流量G1的持续时间是否大于t1，如果是，则执行步骤S508，否则，执行步骤S502S507. Is the duration of the front refrigerant flow G2 greater than the minimum refrigerant flow G1 greater than t1? If yes, go to step S508; otherwise, go to step S502

S508，总排油量进行清零。S508, the total oil discharge is cleared.

S509，判断距离上一次回油的时间是否大于t2。如果是，则执行步骤S510，否则，执行步骤S502。S509. Determine whether the time from the last oil return is greater than t2. If yes, step S510 is performed, otherwise, step S502 is performed.

S510，运行制热回油。S510, running heating and returning oil.

S511，获取距离上一次回油压缩机的总排油量。S511. Obtain the total oil discharge amount from the previous oil return compressor.

S512，总排油量是否大于最大安全排油量，如果是，则执行步骤S510，否则，执行步骤S502。S512, whether the total oil discharge amount is greater than the maximum safe oil discharge amount, and if yes, perform step S510; otherwise, perform step S502.

根据本申请实施例的多联机***的回油控制方法，在***运行的过程中，每隔第一预设时间获取能够将***中的润滑油带回至室外机中所需的最低制冷剂流量和***的当前制冷剂流量，检测并确定当前制冷剂流量小于或等于最低制冷剂流量，获取距离上一次回油压缩机的总排油量，检测并确定总排油量大于最大安全排油量，控制***进行回油。由此，能够保证压缩机不会因排油量大，回油量小而缺油运行，有效提高多联机***的能力能效，且方法简单易行。According to the oil return control method of the multi-online system in the embodiment of the present application, during the system operation, the minimum refrigerant flow rate required to be able to bring the lubricating oil in the system back to the outdoor unit is obtained every first preset time. And the current refrigerant flow of the system, detect and determine that the current refrigerant flow is less than or equal to the minimum refrigerant flow, obtain the total oil discharge from the previous oil return compressor, and detect and determine that the total oil discharge is greater than the maximum safe oil discharge The control system performs oil return. Therefore, it can ensure that the compressor does not run out of oil due to large oil discharge and small oil return, which effectively improves the capacity and energy efficiency of the multi-line system, and the method is simple and easy to implement.

另外，本申请的实施例还提出了一种非临时性计算机可读存储介质，其上存储有计算机程序，该程序被处理器执行时实现上述的冷水机组的回油控制方法。In addition, the embodiment of the present application also proposes a non-transitory computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the oil return control method of the chiller is implemented.

根据本申请实施例提出的非临时性计算机可读存储介质，通过执行上述的多联机***的回油控制方法，能够保证压缩机不会因排油量大，回油量小而缺油运行，有效提高多联机***的能力能效，且方法简单易行。According to the non-transitory computer-readable storage medium proposed in the embodiment of the present application, by implementing the above-mentioned multi-line system oil return control method, it can be ensured that the compressor will not run out of oil due to large oil discharge and small oil return. Effectively improve the capacity and energy efficiency of multi-connection systems, and the method is simple and easy to implement.

图6为根据本申请实施例的多联机***的回油控制装置的方框示意图。FIG. 6 is a block diagram of an oil return control device of a multi-online system according to an embodiment of the present application.

在本申请的实施例中，多联机***包括室外机和多个室内机，室外机包括压缩机。In the embodiment of the present application, the multi-connection system includes an outdoor unit and a plurality of indoor units, and the outdoor unit includes a compressor.

如图6所示，本申请实施例的多联机***的回油控制装置可包括：第一获取模块100、第二获取模块200和控制模块300。As shown in FIG. 6, the oil return control device of the multi-online system according to the embodiment of the present application may include a first acquisition module 100, a second acquisition module 200, and a control module 300.

其中，第一获取模块100用于在***运行的过程中，每隔第一预设时间获取能够将***中的润滑油带回至室外机中所需的最低制冷剂流量。第二获取模块200用于在***运行的过程中，每隔第一预设时间获取***的当前制冷剂流量。控制模块300用于检测并确定当前制冷剂流量小于或等于最低制冷剂流量，获取距离上一次回油压缩机的总排油量，检测并确定总排油量大于最大安全排油量，控制***进行回油。The first obtaining module 100 is configured to obtain the minimum refrigerant flow rate required to be able to bring the lubricating oil in the system back to the outdoor unit every first preset time during the operation of the system. The second acquisition module 200 is configured to acquire the current refrigerant flow rate of the system every first preset time during the operation of the system. The control module 300 is used to detect and determine that the current refrigerant flow rate is less than or equal to the minimum refrigerant flow rate, obtain the total oil discharge amount from the previous oil return compressor, detect and determine that the total oil discharge amount is greater than the maximum safe oil discharge amount, and control the system. Perform oil return.

根据本申请的一个实施例，控制模块300还具体用于，当前制冷剂流量大于最低制冷剂流量，检测并确定当前制冷剂流量大于最低制冷剂流量的持续时间大于第二预设时间；对总排油量进行清零，检测并确定距离上一次回油的时间大于第三预设时间，控制***进行回油，其中，第三预设时间＞第二预设时间＞第一预设时间。According to an embodiment of the present application, the control module 300 is further specifically configured to detect and determine that the duration of the current refrigerant flow that is greater than the minimum refrigerant flow is greater than the second preset time; The oil discharge amount is cleared, the time from the last oil return is detected and determined to be greater than the third preset time, and the control system performs oil return, wherein the third preset time> the second preset time> the first preset time.

根据本申请的一个实施例，上述的多联机***的回油控制装置，还包括：第三获取模块(图中未画出)。第三获取模块用于获取***的当前运行模式；控制模块300还用于识别当前运行模式为制冷模式，控制***进行制冷回油，识别当前运行模式为制热模式，控制 ***进行制热回油。According to an embodiment of the present application, the oil return control device of the multi-online system further includes a third obtaining module (not shown in the figure). The third acquisition module is used to acquire the current operation mode of the system; the control module 300 is also used to identify the current operation mode as a cooling mode, the control system performs cooling and oil return, identifies the current operation mode as a heating mode, and the control system performs heating and oil return .

根据本申请的一个实施例，识别当前运行模式为制冷模式，第一获取模块100具体用于：获取***的饱和蒸发温度，根据饱和蒸发温度获取***的饱和蒸发压力；获取所述***中的润滑油浓度、润滑油密度和冷媒气管的内径；根据所述饱和蒸发压力、所述润滑油浓度、所述润滑油密度和所述冷媒气管的内径，从预设表格中获取所述最低制冷剂流量。According to an embodiment of the present application, the current operating mode is identified as the cooling mode. The first obtaining module 100 is specifically configured to obtain the saturated evaporation temperature of the system, obtain the saturated evaporation pressure of the system according to the saturated evaporation temperature, and obtain the lubrication in the system. Oil concentration, lubricating oil density, and inner diameter of the refrigerant gas pipe; obtaining the minimum refrigerant flow rate from a preset table according to the saturated evaporation pressure, the lubricating oil concentration, the lubricating oil density, and the inner diameter of the refrigerant gas pipe .

根据本申请的一个实施例，识别当前运行模式为制热模式，第一获取模块100具体用于：获取***的排气压力；获取***中的润滑油浓度、润滑油密度和冷媒气管的内径；根据所述排气压力、所述润滑油浓度、所述润滑油密度和所述冷媒气管的内径，从预设表格中获取所述最低制冷剂流量。According to an embodiment of the present application, the current operation mode is identified as the heating mode. The first obtaining module 100 is specifically configured to: obtain the exhaust pressure of the system; obtain the lubricant concentration, the lubricant density, and the inner diameter of the refrigerant gas pipe in the system; The minimum refrigerant flow rate is obtained from a preset table according to the exhaust pressure, the lubricating oil concentration, the lubricating oil density, and an inner diameter of the refrigerant gas pipe.

根据本申请的一个实施例，第二获取模块200具体用于：获取***的排气压力、回气压力和压缩机的当前运行频率；根据排气压力获取***的排气饱和温度；根据回气压力获取***的回气饱和温度；根据排气饱和温度、回气饱和温度和当前运行频率获取当前制冷剂流量。According to an embodiment of the present application, the second obtaining module 200 is specifically configured to: obtain the exhaust pressure, the return pressure of the system, and the current operating frequency of the compressor; obtain the exhaust saturation temperature of the system according to the exhaust pressure; The return air saturation temperature of the pressure acquisition system; the current refrigerant flow rate is obtained according to the exhaust saturation temperature, the return air saturation temperature, and the current operating frequency.

根据本申请的一个实施例，第二获取模块200通过以下公式获取当前制冷剂流量：According to an embodiment of the present application, the second obtaining module 200 obtains the current refrigerant flow rate by the following formula:

此外，本申请的实施例还提出了一种多联机***，该多联机***包括上述的多联机***的回油控制装置。In addition, the embodiment of the present application also proposes a multi-connected system, which includes the oil return control device of the multi-connected system described above.

根据本申请实施例提出的多联机***，通过上述的多联机***的回油控制装置，能够保证压缩机不会因排油量大，回油量小而缺油运行，有效提高多联机***的能力能效，且方法简单易行。According to the multi-connected system provided in the embodiment of the present application, the oil return control device of the multi-connected system can ensure that the compressor does not run out of oil due to large oil discharge and small oil return, which effectively improves the multi-connected system. Ability and energy efficiency, and the method is simple and easy to implement.

另外，在本申请的描述中，术语“中心”、“纵向”、“横向”、“长度”、“宽度”、“厚度”、“上”、“下”、“前”、“后”、“左”、“右”、“竖直”、“水平”、 “顶”、“底”“内”、“外”、“顺时针”、“逆时针”、“轴向”、“径向”、“周向”等指示的方位或位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本申请和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本申请的限制。In addition, in the description of this application, the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inside", "Outside", "Clockwise", "Counterclockwise", "Axial", "Radial" The azimuth or position relationship indicated by "", "circumferential", etc. is based on the azimuth or position relationship shown in the drawings, and is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific The orientation and construction and operation in a particular orientation cannot be understood as a limitation on this application.

此外，术语“第一”、“第二”仅用于描述目的，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”、“第二”的特征可以明示或者隐含地包括至少一个该特征。在本申请的描述中，“多个”的含义是至少两个，例如两个，三个等，除非另有明确具体的限定。In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "plurality" is at least two, for example, two, three, etc., unless it is specifically and specifically defined otherwise.

在本申请中，除非另有明确的规定和限定，第一特征在第二特征“上”或“下”可以是第一和第二特征直接接触，或第一和第二特征通过中间媒介间接接触。而且，第一特征在第二特征“之上”、“上方”和“上面”可是第一特征在第二特征正上方或斜上方，或仅仅表示第一特征水平高度高于第二特征。第一特征在第二特征“之下”、“下方”和“下面”可以是第一特征在第二特征正下方或斜下方，或仅仅表示第一特征水平高度小于第二特征。In this application, unless explicitly stated and limited otherwise, the first feature "on" or "down" of the second feature may be the first and second features in direct contact, or the first and second features indirectly through an intermediate medium. contact. Moreover, the first feature is "above", "above", and "above" the second feature. The first feature is directly above or obliquely above the second feature, or it only indicates that the first feature is higher in level than the second feature. The first feature is “below”, “below”, and “below” of the second feature. The first feature may be directly below or obliquely below the second feature, or it may simply indicate that the first feature is less horizontal than the second feature.

在本说明书的描述中，参考术语“一个实施例”、“一些实施例”、“示例”、“具体示例”、或“一些示例”等的描述意指结合该实施例或示例描述的具体特征、结构、材料或者特点包含于本申请的至少一个实施例或示例中。在本说明书中，对上述术语的示意性表述不必须针对的是相同的实施例或示例。而且，描述的具体特征、结构、材料或者特点可以在任一个或多个实施例或示例中以合适的方式结合。此外，在不相互矛盾的情况下，本领域的技术人员可以将本说明书中描述的不同实施例或示例以及不同实施例或示例的特征进行结合和组合。In the description of this specification, the description with reference to the terms “one embodiment”, “some embodiments”, “examples”, “specific examples”, or “some examples” and the like means specific features described in conjunction with the embodiments or examples , Structure, materials, or features are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. In addition, without any contradiction, those skilled in the art may combine and combine different embodiments or examples and features of the different embodiments or examples described in this specification.

尽管上面已经示出和描述了本申请的实施例，可以理解的是，上述实施例是示例性的，不能理解为对本申请的限制，本领域的普通技术人员在本申请的范围内可以对上述实施例进行变化、修改、替换和变型。Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations on the present application. Those skilled in the art can interpret the above within the scope of the present application. Embodiments are subject to change, modification, substitution, and modification.

Claims

一种多联机***的回油控制方法，其特征在于，所述多联机***包括室外机和多个室内机，所述室外机包括压缩机，所述方法包括以下步骤：A method for controlling oil return of a multi-line system, wherein the multi-line system includes an outdoor unit and a plurality of indoor units, the outdoor unit includes a compressor, and the method includes the following steps:

在***运行的过程中，每隔第一预设时间获取能够将所述***中的润滑油带回至所述室外机中所需的最低制冷剂流量和所述***的当前制冷剂流量；During the operation of the system, the minimum refrigerant flow rate required to be able to bring the lubricating oil in the system back to the outdoor unit and the current refrigerant flow rate of the system are obtained every first preset time;

检测并确定所述当前制冷剂流量小于或等于所述最低制冷剂流量；Detecting and determining that the current refrigerant flow rate is less than or equal to the minimum refrigerant flow rate;

获取距离上一次回油所述压缩机的总排油量；Obtaining the total oil drain from the compressor from the last oil return;

检测并确定所述总排油量大于最大安全排油量；Detecting and determining that the total oil discharge is greater than the maximum safe oil discharge;

控制所述***进行回油。The system is controlled for oil return.
如权利要求1所述的多联机***的回油控制方法，其特征在于，还包括：The oil return control method of the multi-online system according to claim 1, further comprising:

所述当前制冷剂流量大于所述最低制冷剂流量，检测并确认所述当前制冷剂流量大于所述最低制冷剂流量的持续时间大于第二预设时间；The current refrigerant flow rate is greater than the minimum refrigerant flow rate, and detecting and confirming that the duration of the current refrigerant flow rate greater than the minimum refrigerant flow rate is greater than a second preset time;

对所述总排油量进行清零，检测并确认距离上一次回油的时间大于第三预设时间；Clearing the total oil discharge amount, detecting and confirming that the time from the last oil return is greater than the third preset time;

控制所述***进行回油，其中，所述第三预设时间＞所述第二预设时间＞所述第一预设时间。Controlling the system to perform oil return, wherein the third preset time> the second preset time> the first preset time.
如权利要求1或2所述的多联机***的回油控制方法，其特征在于，还包括：The method for controlling oil return of the multi-online system according to claim 1 or 2, further comprising:

获取所述***的当前运行模式；Obtaining the current operating mode of the system;

识别所述当前运行模式为制冷模式，控制所述***进行制冷回油；Identifying that the current operating mode is a cooling mode, and controlling the system to perform refrigeration oil return;

识别所述当前运行模式为制热模式，控制所述***进行制热回油。Identify the current operation mode as a heating mode, and control the system to perform heating and oil return.
如权利要求3所述的多联机***的回油控制方法，其特征在于，获取所述制冷模式下能够将所述***中的润滑油带回至所述室外机中所需的最低制冷剂流量，包括：The oil return control method of the multi-online system according to claim 3, wherein the minimum refrigerant flow rate required to be able to bring the lubricating oil in the system back to the outdoor unit in the cooling mode is obtained. ,include:

获取所述***的饱和蒸发温度，根据所述饱和蒸发温度获取所述***的饱和蒸发压力；Obtaining the saturation evaporation temperature of the system, and obtaining the saturation evaporation pressure of the system according to the saturation evaporation temperature;

获取所述***中的润滑油浓度、润滑油密度和冷媒气管的内径；Obtaining the lubricating oil concentration, the lubricating oil density and the inner diameter of the refrigerant gas pipe in the system;

根据所述饱和蒸发压力、所述润滑油浓度、所述润滑油密度和所述冷媒气管的内径，从预设表格中获取所述最低制冷剂流量。The minimum refrigerant flow rate is obtained from a preset table according to the saturated evaporation pressure, the lubricating oil concentration, the lubricating oil density, and an inner diameter of the refrigerant gas pipe.
如权利要求3所述的多联机***的回油控制方法，其特征在于，获取所述制热模式下能够将所述***中的润滑油带回至所述室外机中所需的最低制冷剂流量，包括：The method for controlling oil return of a multi-online system according to claim 3, wherein the minimum refrigerant required to bring the lubricating oil in the system back to the outdoor unit in the heating mode is obtained. Traffic, including:

获取所述***的排气压力；Obtaining exhaust pressure of the system;

获取***中的润滑油浓度、润滑油密度和冷媒气管的内径；Obtain the lubricant concentration, lubricant density and the inner diameter of the refrigerant gas pipe in the system;

根据所述排气压力、所述润滑油浓度、所述润滑油密度和所述冷媒气管的内径，从预设表格中获取所述最低制冷剂流量。The minimum refrigerant flow rate is obtained from a preset table according to the exhaust pressure, the lubricating oil concentration, the lubricating oil density, and an inner diameter of the refrigerant gas pipe.
如权利要求1或2所述的多联机***的回油控制方法，其特征在于，所述获取所述 ***的当前制冷剂流量，包括：The method for controlling oil return of a multi-online system according to claim 1 or 2, wherein the obtaining the current refrigerant flow of the system comprises:

获取所述***的排气压力、回气压力和所述压缩机的当前运行频率；Obtaining exhaust pressure, return pressure of the system and the current operating frequency of the compressor;

根据所述排气压力获取所述***的排气饱和温度；Obtaining an exhaust saturation temperature of the system according to the exhaust pressure;

根据所述回气压力获取所述***的回气饱和温度；Obtaining the return air saturation temperature of the system according to the return air pressure;

根据所述排气饱和温度、所述回气饱和温度和所述当前运行频率获取所述当前制冷剂流量。The current refrigerant flow rate is obtained according to the exhaust gas saturation temperature, the return gas saturation temperature, and the current operating frequency.
如权利要求6所述的多联机***的回油控制方法，其特征在于，通过以下公式获取所述当前制冷剂流量：The oil return control method of the multi-online system according to claim 6, wherein the current refrigerant flow rate is obtained by the following formula:

其中，G2为所述当前制冷剂流量，S为所述回气饱和温度，D为所述排气饱和温度，C0至C9为计算系数，所述C0至C9根据所述当前运行频率获取。Among them, G2 is the current refrigerant flow rate, S is the return gas saturation temperature, D is the exhaust gas saturation temperature, C0 to C9 are calculation coefficients, and C0 to C9 are obtained according to the current operating frequency.
一种非临时性计算机可读存储介质，其上存储有计算机程序，其特征在于，该程序被处理器执行时实现如权利要求1-7中任一项所述的多联机***的回油控制方法。A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that the program, when executed by a processor, implements oil return control of the multi-online system according to any one of claims 1-7. method.
一种多联机***的回油控制装置，其特征在于，所述多联机***包括室外机和多个室内机，所述室外机包括压缩机，所述装置包括：An oil return control device for a multi-line system, characterized in that the multi-line system includes an outdoor unit and a plurality of indoor units, the outdoor unit includes a compressor, and the device includes:

第一获取模块，用于在***运行的过程中，每隔第一预设时间获取能够将所述***中的润滑油带回至所述室外机中所需的最低制冷剂流量；A first obtaining module, configured to obtain, at a first preset time, the minimum refrigerant flow required to bring the lubricating oil in the system back to the outdoor unit during the system operation;

第二获取模块，用于在所述***运行的过程中，每隔所述第一预设时间获取所述***的当前制冷剂流量；A second acquisition module, configured to acquire the current refrigerant flow rate of the system every first preset time during the operation of the system;

控制模块，用于检测并确定所述当前制冷剂流量小于或等于所述最低制冷剂流量，获取距离上一次回油所述压缩机的总排油量，检测并确定所述总排油量大于最大安全排油量，控制所述***进行回油。A control module, configured to detect and determine that the current refrigerant flow rate is less than or equal to the minimum refrigerant flow rate, obtain a total oil discharge amount from the compressor that returned to the previous oil return, and detect and determine that the total oil discharge amount is greater than Maximum safe oil discharge, controlling the system for oil return.
如权利要求9所述的多联机***的回油控制装置，其特征在于，所述控制模块还具体用于，所述当前制冷剂流量大于所述最低制冷剂流量，检测并确认所述当前制冷剂流量大于所述最低制冷剂流量的持续时间大于第二预设时间；，对所述总排油量进行清零，检测并确认距离上一次回油的时间大于第三预设时间，控制所述***进行回油，其中，所述第三预设时间＞所述第二预设时间＞所述第一预设时间。The oil return control device of the multi-online system according to claim 9, wherein the control module is further specifically configured to detect and confirm the current refrigerant flow when the current refrigerant flow rate is greater than the minimum refrigerant flow rate. The duration of the agent flow rate greater than the minimum refrigerant flow rate is greater than the second preset time; clearing the total oil discharge amount, detecting and confirming that the time from the last oil return is greater than the third preset time, and controlling the The system performs oil return, wherein the third preset time> the second preset time> the first preset time.
如权利要求9或10所述的多联机***的回油控制装置，其特征在于，还包括：The oil return control device of the multi-online system according to claim 9 or 10, further comprising:

第三获取模块，用于获取所述***的当前运行模式；A third acquisition module, configured to acquire a current operating mode of the system;

所述控制模块，还用于识别所述当前运行模式为制冷模式，控制所述***进行制冷回油，识别所述当前运行模式为制热模式，控制所述***进行制热回油。The control module is further configured to identify the current operation mode as a cooling mode, control the system to perform cooling and oil return, identify the current operation mode as a heating mode, and control the system to perform heating and oil return.
如权利要求11所述的多联机***的回油控制装置，其特征在于，识别所述当前运行模式为所述制冷模式，所述第一获取模块具体用于：The oil return control device of the multi-online system according to claim 11, wherein the current operation mode is identified as the cooling mode, and the first obtaining module is specifically configured to:

获取所述***的饱和蒸发温度，根据所述饱和蒸发温度获取所述***的饱和蒸发压力；Obtaining the saturation evaporation temperature of the system, and obtaining the saturation evaporation pressure of the system according to the saturation evaporation temperature;

获取所述***中的润滑油浓度、润滑油密度和冷媒气管的内径；Obtaining the lubricating oil concentration, the lubricating oil density and the inner diameter of the refrigerant gas pipe in the system;

根据所述饱和蒸发压力、所述润滑油浓度、所述润滑油密度和所述冷媒气管的内径，从预设表格中获取所述最低制冷剂流量。The minimum refrigerant flow rate is obtained from a preset table according to the saturated evaporation pressure, the lubricating oil concentration, the lubricating oil density, and an inner diameter of the refrigerant gas pipe.
如权利要求11所述的多联机***的回油控制装置，其特征在于，识别所述当前运行模式为所述制热模式，所述第一获取模块具体用于：The oil return control device of the multi-online system according to claim 11, wherein the current operation mode is identified as the heating mode, and the first obtaining module is specifically configured to:

获取所述***的排气压力；Obtaining exhaust pressure of the system;

获取***中的润滑油浓度、润滑油密度和冷媒气管的内径；Obtain the lubricant concentration, lubricant density and the inner diameter of the refrigerant gas pipe in the system;

根据所述排气压力、所述润滑油浓度、所述润滑油密度和所述冷媒气管的内径，从预设表格中获取所述最低制冷剂流量。The minimum refrigerant flow rate is obtained from a preset table according to the exhaust pressure, the lubricating oil concentration, the lubricating oil density, and an inner diameter of the refrigerant gas pipe.
如权利要求9或10所述的多联机***的回油控制装置，其特征在于，所述第二获取模块具体用于：The oil return control device of the multi-online system according to claim 9 or 10, wherein the second acquisition module is specifically configured to:

获取所述***的排气压力、回气压力和所述压缩机的当前运行频率；Obtaining exhaust pressure, return pressure of the system and the current operating frequency of the compressor;

根据所述排气压力获取所述***的排气饱和温度；Obtaining an exhaust saturation temperature of the system according to the exhaust pressure;

根据所述回气压力获取所述***的回气饱和温度；Obtaining the return air saturation temperature of the system according to the return air pressure;

根据所述排气饱和温度、所述回气饱和温度和所述当前运行频率获取所述当前制冷剂流量。The current refrigerant flow rate is obtained according to the exhaust gas saturation temperature, the return gas saturation temperature, and the current operating frequency.
如权利要求14所述的多联机***的回油控制装置，其特征在于，所述第二获取模块通过以下公式获取所述当前制冷剂流量：The oil return control device of the multiple on-line system according to claim 14, wherein the second obtaining module obtains the current refrigerant flow rate by the following formula:

其中，G2为所述当前制冷剂流量，S为所述回气饱和温度，D为所述排气饱和温度，C0至C9为计算系数，所述C0至C9根据所述当前运行频率获取。Among them, G2 is the current refrigerant flow rate, S is the return gas saturation temperature, D is the exhaust gas saturation temperature, C0 to C9 are calculation coefficients, and C0 to C9 are obtained according to the current operating frequency.
一种多联机***，其特征在于，包括如权利要求9-15中任一项所述的多联机***的回油控制装置。A multi-line system, comprising the oil return control device of the multi-line system according to any one of claims 9-15.