WO2017107111A1 - 基于开度的满液式螺杆机组供液量控制方法及装置 - Google Patents

基于开度的满液式螺杆机组供液量控制方法及装置 Download PDF

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WO2017107111A1
WO2017107111A1 PCT/CN2015/098488 CN2015098488W WO2017107111A1 WO 2017107111 A1 WO2017107111 A1 WO 2017107111A1 CN 2015098488 W CN2015098488 W CN 2015098488W WO 2017107111 A1 WO2017107111 A1 WO 2017107111A1
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expansion valve
electronic expansion
opening degree
flow rate
compressor
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PCT/CN2015/098488
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French (fr)
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詹坤田
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詹坤田
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Priority to PCT/CN2015/098488 priority Critical patent/WO2017107111A1/zh
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B41/00—Fluid-circulation arrangements

Definitions

  • the invention relates to a screw compressor group in the refrigeration industry, in particular to a method and a device for controlling the liquid supply amount of a screw unit.
  • a full-liquid screw compressor unit which mainly comprises a screw compressor, a condenser, an electronic expansion valve, an evaporator, a control system, etc., a screw compressor, a condenser, and an electronic expansion valve.
  • the evaporator and the evaporator are connected in series through a pipeline to form a closed system, and the closed system is filled with a refrigerant.
  • the control system uses PLC or single chip as the main components, combined with the corresponding interface circuit and execution circuit, adjusts the temperature, pressure and opening of the electronic expansion valve in the closed system.
  • the control system includes the power supply part and the automatic control part, and the power supply part. It supplies power to compressors, fans, pumps, etc. through contactors.
  • the automatic control part includes temperature control sensor, pressure sensor, various relays, overload protection, etc.
  • the automatic control part automatically starts and stops according to the temperature, and can also provide power-off protection for various abnormal working conditions.
  • the disadvantage of the prior art is that the control system approximately replaces the superheat of the system according to the difference of the measured temperature, and uses the superheat as a parameter to control the electronic expansion valve, which is not accurate enough, and the fluctuation of the control is large, reaching a steady state. Long time.
  • One of the objects of the present invention is to provide a liquid supply amount control method for a full-liquid screw unit based on opening degree, so that the opening degree of the electronic expansion valve can be accurately controlled according to working conditions.
  • the object of the present invention is achieved by a method for controlling the liquid supply amount of a full-liquid screw unit based on opening degree, comprising the following steps:
  • Y 1 is the mass flow rate of the refrigerant when the electronic expansion valve is fully open, and the unit is kg/h;
  • X is the pressure difference measurement value at both ends of the electronic expansion valve, and the unit is kgf/cm 2 ;
  • the suction and discharge pressures measured by the PLC by the pressure sensor are variables, and according to the fitting equation 2, the suction mass flow rate per unit section of the compressor under the corresponding working conditions is calculated, and the flow of the compressor suction valve is opened.
  • the cross-sectional area is S 2 ;
  • Y 2 is the suction mass flow rate per unit section of the compressor, and the unit is kg/h;
  • Pe is the compressor suction pressure, the unit is kgf/cm 2 ;
  • Pc is the compressor discharge pressure, and the unit is kgf/cm 2 ;
  • the PLC needs to set the opening degree of the electronic expansion valve when the mass flow rate of the refrigerant flowing through the electronic expansion valve is equal to the suction mass flow rate of the compressor; the PLC calculates according to the following formula:
  • Opening degree K Y 2 S 2 /Y 1 S 1 ;
  • the fitting equation 1 and the fitting equation 2 are based on the actual detected working condition, and the corresponding curve is drawn according to the specific diameter electronic expansion valve and the specific compressor, and then converted into a curve similar to the curve.
  • the fitting equation is used to calculate the working condition, and then controlled by the PLC, and finally corrected, so that the number of opening steps of the given electronic expansion valve can quickly reach a stable state matching the actual working condition.
  • the method is accurate in control, can quickly achieve control steady state according to working conditions, and improves the accuracy of control.
  • step 5 ⁇ T is not corrected in the interval of +0.2 to -0.2 °C; when ⁇ T is greater than 0.2 °C, the opening of the electronic expansion valve is increased by 1% every 5 seconds, and the maximum increase is 5%. ; ⁇ T is less than -0.2 ° C, the electronic expansion valve opening is reduced by 1% every 5S; the maximum reduction is 5%.
  • step 3 the opening calculation result takes the value to the third decimal place and is rounded off.
  • the above control precision can reach 0.1%, and its precision is high.
  • Another object of the present invention is to provide a liquid supply amount control device for a full-liquid screw unit based on a calculated opening degree method, the device having means for carrying out steps 1) to 6) of claim 1.
  • the liquid supply control of the full-liquid screw unit based on the opening degree, the compressor, the condenser, the electronic expansion valve and the evaporator constitute a closed circulation system, and each device is provided with a temperature sensor and a pressure sensor, respectively.
  • the refrigerant mass flow rate of the electronic expansion valve flowing through the unit section is calculated when the electronic expansion valve is 100% open,
  • the maximum flow area of the electronic expansion valve is S 1 ;
  • the maximum flow area of the electronic expansion valve is 2.8 to 3.0 cm 2
  • Y 1 is the mass flow rate of the refrigerant when the electronic expansion valve is fully open, and the unit is kg/h;
  • X is the pressure difference measurement value at both ends of the electronic expansion valve, and the unit is kgf/cm 2 ;
  • the suction and discharge pressures measured by the PLC by the pressure sensor are variables, and according to the fitting equation 2, the suction mass flow rate per unit section of the compressor under the corresponding working conditions is calculated, and the flow of the compressor suction valve is opened.
  • the cross-sectional area is S 2 ; preferably 15.7 to 25.2 cm 2
  • Y 2 is the suction mass flow rate per unit section of the compressor, and the unit is kg/h;
  • Pe is the compressor suction pressure, the unit is kgf/cm 2 ;
  • Pc is the compressor discharge pressure, and the unit is kgf/cm 2 ;
  • the PLC needs to set the opening degree of the electronic expansion valve when the mass flow rate of the refrigerant flowing through the electronic expansion valve is equal to the suction mass flow rate of the compressor; the PLC calculates according to the following formula:
  • the opening degree K Y 2 S 2 /Y 1 S 1 ; the calculation result of the opening degree takes the value to the third place after the decimal point, rounding off;

Abstract

一种制冷技术领域内的基于开度的满液式螺杆机组供液量控制方法及装置，其通过拟合方程一和拟合方程二根据实际检测的工况，计算得到电子膨胀阀的开度，并根据实际工况通过PLC进行控制，最后经修正，使得给出的电子膨胀阀开启步数能很快达到与实际工况相匹配的稳定状态。与现有技术相比，该方法控制准确，能根据工况很快达到控制稳态，提高了制冷系统控制的准确性。

Description

基于开度的满液式螺杆机组供液量控制方法及装置 技术领域
本发明涉及一种制冷行业内的螺杆压缩机组，特别涉及一种螺杆机组供液量的控制方法及装置。
背景技术
现有的制冷行业中，广泛使用满液式螺杆压缩机组，该装置主要包括有螺杆压缩机、冷凝器、电子膨胀阀、蒸发器、控制系统等组成，螺杆压缩机、冷凝器、电子膨胀阀和蒸发器经由管路依次串接成封闭系统，封闭系统内充注有制冷剂。控制系统以PLC或单片机为主要部件，结合相应的接口电路和执行电路，对封闭系统内的温度、压力及电子膨胀阀的开度等进行调整，控制系统包括电源部分和自动控制部分，电源部分是通过接触器，对压缩机、风扇、水泵等供应电源。自动控制部分包括温控传感器、压力传感器、各种继电器、过载保护等，自动控制部分根椐温度自动启停，同时可对各种非正常工况进行断电保护。现有技术的缺点在于：控制系统根据测定的温度的差近似地代替系统过热度，并用此过热度作为参数进行电子膨胀阀的控制，这一控制不够准确，控制的波动性大，达到稳态的时间长。
发明内容
本发明的目的之一是提供一种基于开度的满液式螺杆机组供液量控制方法，使其能根据工况准确控制电子膨胀阀的开度。
本发明的目的是这样实现的：一种基于开度的满液式螺杆机组供液量控制方法，包括如下步骤：
1)由PLC根据由压力传感器测量到的电子膨胀阀前后的压差，根据拟合成方程一，计算电子膨胀阀100％开度时，流过单位截面的电子膨胀阀的制冷剂质量流量，所述电子膨胀阀的最大通流面积为S1；
所述拟合方程一为：
Y1＝0.432X3-4.135X2+21.15X+266.31
Y1为电子膨胀阀的全开时的制冷剂质量流量，单位为kg/h；X为电子膨胀阀两端的压差测量值，单位为kgf/cm2；
2)由PLC以压力传感器测量到的压缩机吸、排气压力为变量，根据拟合方程二计算相应工况条件下压缩机单位截面吸气质量流量，压缩机吸气阀开启时的通流截面积为S2；
所述拟合方程二为：
Y2＝64987+3718.11Pe-388.47Pc+18.079Pe2-12.567PePc-3.975Pc2+1.589Pe3-1.444PcPe2-0.75PePc2-0.168Pc3
其中，Y2为压缩机单位截面的吸气质量流量，单位为kg/h；Pe为压缩机吸气压力，单位为kgf/cm2；Pc为压缩机排气压力，单位为kgf/cm2；
3)由PLC根据上述结果，设定流过电子膨胀阀的制冷剂质量流量与压缩机的吸气质量流量相等时，电子膨胀阀所需开度；PLC根据如下公式计算：
开度K＝Y2S2/Y1S1；
4)根据实时测量的吸气过热度情况，对电子膨胀阀的开度计算结果进行实时修正；t1为人为设定的最佳过热度所对应的温度值，t2为实际测量值，计算△T＝t1-t2；
5)比较△T与设定的动作区间值±t0，在动作区间值内的不作修正，超出动作区间值外的，则根据设定的动作幅度和频率，PLC改变电子膨胀阀开度信号；并根据修正后的开度信号发出步数信号，控制电子膨胀阀打开到相应步数；
6)根据设定的频率，重复步骤2)-步骤5)。
本发明中，拟合方程一和拟合方程二是申请人根据实际检测的工况，根据特定口径的电子膨胀阀和特定的压缩机，绘制出相应的曲线，再转换成与该曲线相近似的方程，再验证范围的不同的电子膨胀阀和螺杆压缩机，证明该拟合方程具有正确性。将该拟合方程用于计算中工况，再通过PLC进行控制，最后经修正，使得给出的电子膨胀阀开启步数能很快达到与实际工况相匹配的稳定状态。与现有技术相比，该方法控制准确，能根据工况很快达到控制稳态，提高了控制的准确性。
作为本发明的进一步改进，在步骤5)中，△T在+0.2～-0.2℃区间中不做修正；△T大于0.2℃时，电子膨胀阀开度每5S增加1％，最大增加5％；△T小于-0.2℃，电子膨胀阀开度每5S减小1％；最大减小5％。在步骤3)中，开度计算结果取值到小数点后第三位，四舍五入。上述控制精度可达0.1％，其精度较高。
本发明目的二是是提供一种基于计算开度法的满液式螺杆机组供液量控制装置，该装置具有包含实现权利要求1中步骤1)～6)的装置。
具体实施方式
一种基于开度的满液式螺杆机组供液量控制，其压缩机、冷凝器、电子膨胀阀及蒸发器构成闭式循环系统，各设备上分别设有温度传感器和压力传感器，这些传感器均接入PLC，其工作时，按如下步骤进行：
1)由PLC根据由压力传感器测量到的电子膨胀阀前后的压差，根据拟合成方程一，计算电子膨胀阀100％开度时，流过单位截面的电子膨胀阀的制冷剂质量流量，所述电子膨胀阀的 最大通流面积为S1；电子膨胀阀的最大通流面积为2.8～3.0cm2
所述拟合方程一为：
Y1＝0.432X3-4.135X2+21.15X+266.31
Y1为电子膨胀阀的全开时的制冷剂质量流量，单位为kg/h；X为电子膨胀阀两端的压差测量值，单位为kgf/cm2；
2)由PLC以压力传感器测量到的压缩机吸、排气压力为变量，根据拟合方程二计算相应工况条件下压缩机单位截面吸气质量流量，压缩机吸气阀开启时的通流截面积为S2；优选为15.7～25.2cm2
所述拟合方程二为：
Y2＝64987+3718.11Pe-388.47Pc+18.079Pe2-12.567PePc-3.975Pc2+1.589Pe3-1.444PcPe2-0.75PePc2-0.168Pc3
其中，Y2为压缩机单位截面的吸气质量流量，单位为kg/h；Pe为压缩机吸气压力，单位为kgf/cm2；Pc为压缩机排气压力，单位为kgf/cm2；
3)由PLC根据上述结果，设定流过电子膨胀阀的制冷剂质量流量与压缩机的吸气质量流量相等时，电子膨胀阀所需开度；PLC根据如下公式计算：
开度K＝Y2S2/Y1S1；开度计算结果取值到小数点后第三位，四舍五入；
4)根据实时测量的吸气过热度情况，对电子膨胀阀的开度计算结果进行实时修正；t1为人为设定的最佳过热度所对应的温度值，t2为实际测量值，计算△T＝t1-t2；
5)比较△T与设定的动作区间值±t0，在动作区间值内的不作修正，超出动作区间值外的，则根据设定的动作幅度和频率，PLC改变电子膨胀阀开度信号；并根据修正后的开度信号发出步数信号，控制电子膨胀阀打开到相应步数；△T在+0.2～-0.2℃区间中不做修正；△T大于0.2℃时，电子膨胀阀开度每5S增加1％，最大增加5％；△T小于-0.2℃，电子膨胀阀开度每5S减小1％；最大减小5％；
6)根据设定的频率，重复步骤2)-步骤5)。
本发明并不局限于上述实施例，在本发明公开的技术方案的基础上，本领域的技术人员根据所公开的技术内容，不需要创造性的劳动就可以对其中的一些技术特征作出一些替换和变形，这些替换和变形均在本发明的保护范围内。

Claims (4)

  1. 一种基于开度的满液式螺杆机组供液量控制方法，其特征在于包括如下步骤：
    1)由PLC根据由压力传感器测量到的电子膨胀阀前后的压差，根据拟合成方程一，计算电子膨胀阀100％开度时，流过单位截面的电子膨胀阀的制冷剂质量流量，所述电子膨胀阀的最大通流面积为S1；
    所述拟合方程一为：
    Y1＝0.432X3-4.135X2+21.15X+266.31
    Y1为电子膨胀阀的全开时的制冷剂质量流量，单位为kg/h；X为电子膨胀阀两端的压差测量值，单位为kgf/cm2；
    2)由PLC以压力传感器测量到的压缩机吸、排气压力为变量，根据拟合方程二计算相应工况条件下压缩机单位截面吸气质量流量，压缩机吸气阀开启时的通流截面积为S2；
    所述拟合方程二为：
    Y2＝64987+3718.11Pe-388.47Pc+18.079Pe2-12.567PePc-3.975Pc2+1.589Pe3-1.444PcPe2-0.75PePc2-0.168Pc3
    其中，Y2为压缩机单位截面的吸气质量流量，单位为kg/h；Pe为压缩机吸气压力，单位为kgf/cm2；Pc为压缩机排气压力，单位为kgf/cm2；
    3)由PLC根据上述结果，设定流过电子膨胀阀的制冷剂质量流量与压缩机的吸气质量流量相等时，电子膨胀阀所需开度；PLC根据如下公式计算：
    开度K＝Y2S2/Y1S1；
    4)根据实时测量的吸气过热度情况，对电子膨胀阀的开度计算结果进行实时修正；t1为人为设定的最佳过热度所对应的温度值，t2为实际测量值，计算△T＝t1-t2；
    5)比较△T与设定的动作区间值±t0，在动作区间值内的不作修正，超出动作区间值外的，则根据设定的动作幅度和频率，PLC改变电子膨胀阀开度信号；并根据修正后的开度信号发出步数信号，控制电子膨胀阀打开到相应步数；
    6)根据设定的频率，重复步骤2)-步骤5)。
  2. 根据权利要求1所述的基于开度的满液式螺杆机组供液量控制方法，其特征在于：步骤5)中，△T在+0.2～-0.2℃区间中不做修正；△T大于0.2℃时，电子膨胀阀开度每5S增加1％，最大增加5％；△T小于-0.2℃，电子膨胀阀开度每5S减小1％；最大减小5％。
  3. 根据权利要求2所述的基于开度的满液式螺杆机组供液量控制方法，其特征在于：开度计算结果取值到小数点后第三位，四舍五入。
  4. 一种基于开度的满液式螺杆机组供液量控制装置，其特征在于：其具有包含实现权利要求1中步骤1)～6)的装置。
PCT/CN2015/098488 2015-12-23 2015-12-23 基于开度的满液式螺杆机组供液量控制方法及装置 WO2017107111A1 (zh)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20070062343A (ko) * 2005-12-12 2007-06-15 주식회사 대우일렉트로닉스 기포 발생기를 구비한 열교환장치 및 그 제어방법
CN102466376A (zh) * 2010-11-18 2012-05-23 海尔集团公司 螺杆式制冷系统及其控制方法
CN104345743A (zh) * 2013-07-23 2015-02-11 丹佛斯公司 满液式空调系统的冷媒液位控制方法
CN104567159A (zh) * 2014-12-26 2015-04-29 珠海格力电器股份有限公司 制冷机组的压差控制方法及制冷机组
CN104913459A (zh) * 2015-06-25 2015-09-16 山东格瑞德集团有限公司 制冷空调冷媒流量实时控制方法及装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20070062343A (ko) * 2005-12-12 2007-06-15 주식회사 대우일렉트로닉스 기포 발생기를 구비한 열교환장치 및 그 제어방법
CN102466376A (zh) * 2010-11-18 2012-05-23 海尔集团公司 螺杆式制冷系统及其控制方法
CN104345743A (zh) * 2013-07-23 2015-02-11 丹佛斯公司 满液式空调系统的冷媒液位控制方法
CN104567159A (zh) * 2014-12-26 2015-04-29 珠海格力电器股份有限公司 制冷机组的压差控制方法及制冷机组
CN104913459A (zh) * 2015-06-25 2015-09-16 山东格瑞德集团有限公司 制冷空调冷媒流量实时控制方法及装置

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