CN111351307A - Control method for compressor of cascade ultralow-temperature refrigerator - Google Patents

Control method for compressor of cascade ultralow-temperature refrigerator Download PDF

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Publication number
CN111351307A
CN111351307A CN202010163974.7A CN202010163974A CN111351307A CN 111351307 A CN111351307 A CN 111351307A CN 202010163974 A CN202010163974 A CN 202010163974A CN 111351307 A CN111351307 A CN 111351307A
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temperature
compressor
frequency
refrigerator
time
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CN111351307B (en
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刘发柱
于吉帅
龙霄飞
姚金龙
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Bingshan Songyang Biotechnology Dalian Co ltd
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Bingshan Songyang Biotechnology Dalian Co ltd
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25DREFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
    • F25D29/00Arrangement or mounting of control or safety devices
    • F25D29/003Arrangement or mounting of control or safety devices for movable devices
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B49/00Arrangement or mounting of control or safety devices
    • F25B49/02Arrangement or mounting of control or safety devices for compression type machines, plants or systems
    • F25B49/022Compressor control arrangements
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02BCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B40/00Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Devices That Are Associated With Refrigeration Equipment (AREA)
  • Air Conditioning Control Device (AREA)

Abstract

The invention discloses a control method of a cascade ultralow temperature refrigerator compressor, which comprises the following steps: setting a temperature time period of turning on the low-temperature compressor, a temperature time period of turning off the low-temperature compressor and a target control temperature time period, and turning on the low-temperature compressor when the real-time temperature t of the refrigerator is greater than the lowest temperature of the temperature time period of turning on the low-temperature compressor; when the real-time temperature t of the refrigerator is less than the highest temperature of the temperature period of closing the low-temperature compressor, closing the low-temperature compressor; when the real-time temperature t of the refrigerator is in the target control temperature period, a cycle period control strategy is adopted to control the low-temperature compressor: and the rotating speed of the low-temperature compressor is controlled by adopting a PID control algorithm, so that the real-time temperature t of the refrigerator is regulated and controlled within a target control temperature period. The method avoids frequent start and stop of the compressor, can improve the temperature uniformity in the refrigerator, and simultaneously adopts a frequency conversion mode to automatically search the minimum operating frequency of the high-temperature compressor, so that the power of the high-temperature compressor can be reduced to the maximum extent on the premise of ensuring the refrigerating capacity.

Description

Control method for compressor of cascade ultralow-temperature refrigerator
Technical Field
The invention relates to the field of control over ultra-low temperature refrigerators, in particular to a control method for a compressor of a cascade ultra-low temperature refrigerator.
Background
The cascade ultralow temperature refrigerator is mainly applied to the aspects of vaccines, sperms, samples, biological reagents and cell storage in the current market, wherein the cascade ultralow temperature refrigerator is mainly applied to high-tech and high-added-value industries such as scientific research of scientific research institutions and hospitals, cell therapy and the like in the field of biological medical treatment.
Against the background of national emphasis on the medical industry and on the possible premise of occasional serious epidemics, the biomedical industry has met with unprecedented challenges and opportunities. The ultra-low temperature refrigerator plays an important role in cell storage. In the existing cascade type ultralow temperature refrigerator temperature control, high and low temperature compressors are controlled in a fixed frequency mode, and the start and stop of the compressors are controlled according to required temperature zones respectively; the compressors are high in power, so that the power consumption is high, and the uniformity of the temperature in the refrigerator is poor.
Disclosure of Invention
According to the problems in the prior art, the invention discloses a control method of a cascade ultralow temperature refrigerator compressor, which specifically comprises the following steps:
setting a temperature time period of turning on the low-temperature compressor, a temperature time period of turning off the low-temperature compressor and a target control temperature time period, and turning on the low-temperature compressor when the real-time temperature t of the refrigerator is greater than the lowest temperature of the temperature time period of turning on the low-temperature compressor; when the real-time temperature t of the refrigerator is less than the highest temperature of the temperature period of closing the low-temperature compressor, closing the low-temperature compressor; when the real-time temperature t of the refrigerator is in the target control temperature period, a cycle period control strategy is adopted to control the low-temperature compressor: and the rotating speed of the low-temperature compressor is controlled by adopting a PID control algorithm, so that the real-time temperature t of the refrigerator is regulated and controlled within a target control temperature period.
The loop period control strategy mode is as follows:
setting a target temperature value St, an upper limit control deviation div1 and a lower limit control deviation div2 in the refrigerator, wherein the temperature time interval of the start-up low-temperature compressor is St + div1, the temperature time interval of the shut-down low-temperature compressor is St-div2, and the target control temperature time interval is St-div2< t < St + div 1;
and acquiring the running frequency of the compressor through a PID algorithm according to the deviation value obtained by the target temperature St in the refrigerator and the real-time temperature t of the refrigerator, transmitting the running frequency signal to the frequency converter by the controller, and adjusting the output frequency, namely the running rotating speed, of the compressor by the frequency converter so as to adjust the real-time temperature in the refrigerator.
When the real-time temperature t of the refrigerator is in the target control temperature period, namely St-sp2 is less than or equal to t is less than or equal to St + sp1, and the temperature exceeds the time t in the range1Then, starting to perform self-adjustment of the frequency of the high-temperature stage compressor, and setting the step length of the search frequency to be H0The operation frequency of the compressor is controlled to be reduced, the real-time temperature t in the refrigerator is still controlled within the range that t is more than or equal to St-sp2 and less than or equal to St + sp1, and the operation frequency of the frequency converter subjected to nth frequency reduction is Hn-HH-n×H0
If the compressor is reducing the running frequency, the real-time temperature t of the refrigerator>St + sp1, the high temperature compressor is controlled to increase the operation frequency, and if the high temperature compressor is increased in frequency, the frequency Hn is equal to HH-n×H0+0.5×H0Is carried out byHRepresents the highest frequency, if the temperature St-sp2 ≦ t ≦ St + sp1 is controlled and the temperature exceeds the time t within this range1Then, the frequency of the compressor is controlled continuously, when the compressor is driven by Hn ═ HH-n×H0+0.5×H0-0.25×H0And t is>St + sp1, the frequency Hn of the compressor is HH-n×H0+0.5×H0Operation, if the operating frequency is locked and operated at the compressor, t occurs>St + sp1, then the operating frequency is increased by 0.25 × H each time0Increasing the time to t1Said t is1Is a frequency detection period.
Due to the adoption of the technical scheme, the method for controlling the compressor of the cascade ultralow temperature refrigerator avoids frequent start and stop of the compressor, can improve the temperature uniformity in the refrigerator, and simultaneously adopts a frequency conversion mode to automatically search the minimum operating frequency of the high-temperature compressor, so that the power of the high-temperature compressor is reduced to the maximum extent on the premise of ensuring the refrigerating capacity, and the electric consumption is reduced.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present application, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a schematic illustration of the method of the present invention;
FIG. 2 is a schematic diagram of the PID algorithm employed in the method of the invention.
Detailed Description
In order to make the technical solutions and advantages of the present invention clearer, the following describes the technical solutions in the embodiments of the present invention clearly and completely with reference to the drawings in the embodiments of the present invention:
a control method for a compressor of a cascade ultra-low temperature refrigerator adopts the energy-saving principle of a frequency converter in the structure of the cascade ultra-low temperature refrigerator as follows: under the condition that the load is not changed (the running current of the compressor is not changed), the running frequency of the compressor is reduced, the amplitude of the voltage applied to the compressor is reduced, and the running power of the compressor is reduced according to the condition that the running current of the compressor is not changed. The low-temperature compressor is specifically controlled in the following way: a, B, C are divided into three temperature areas as shown in FIG. 1, area A is the period of time for turning on the low temperature compressor, area B is the period of time for turning off the low temperature compressor, and area C is the period of time for controlling the target temperature. Namely, when the real-time temperature t in the tank is detected to be more than or equal to St + div1, the low-temperature compressor is started; when the temperature t in the box is less than or equal to St-div2, turning off the low-temperature compressor; when St-div2< t < St + div1, it is in the process of temperature control cycle. Where St is the in-tank temperature set point, div1 is the upper limit control deviation, and div2 is the lower limit control deviation. The starting point and the shutdown point are set to prevent the frequency converter from malfunctioning, and the frequency converter still outputs and controls the compressor to work when the frequency converter is shut down.
Further, as shown in FIG. 2, when the low-temperature compressor is in circulation control, a PID control algorithm is adopted to give a frequency signal to the frequency converter through the controller, the frequency converter adjusts the running rotating speed of the low-temperature compressor, and adjusts the real-time temperature in the box, so that the actual value of the temperature in the box is between St-sp2 and St + sp1, namely the control temperature St-sp2 is not less than t and not more than St + sp1, wherein t is the real-time temperature in the box. The PID algorithm is implemented by taking St as a target temperature value and t as a detected actual temperature, and calculating the frequency of the compressor needing to operate by calculating an offset value obtained by subtracting St and t through the PID algorithm. The controller transmits the frequency signal to the frequency converter, and the frequency converter adjusts the output frequency of the compressor, namely the running speed, so as to adjust the temperature in the box.
In addition, the method also performs frequency conversion control on the high-temperature compressor: after the high-temperature-stage compressor is electrified and meets the starting condition, the high-temperature-stage compressor firstly runs at the highest rotating speed with the running frequency of HHI.e. the highest frequency. As can be seen from the above, energy saving can also be achieved by reducing the operating frequency of the high-temperature compressor when the in-box temperature is satisfied. The frequency adjusting method comprises the following steps: under different operating environments, when the temperature in the box is met, the optimal operating frequency (minimum operating frequency) of the high-temperature compressor is automatically searched, so that the high-temperature compressor operates at the minimum frequency.
The specific embodiment of the method disclosed by the invention is as follows: if the temperature St-sp2 ≦ t ≦ St + sp1 is controlled and the temperature exceeds the time t within this range1Then, the automatic adjustment of the high-temperature stage compressor frequency is started, and the search frequency step length is set to be H0Then, the following cases are described:
(1) the temperature St-sp2 is controlled to be more than or equal to t and less than or equal to St + sp1, and the temperature exceeds the time t in the range1Then the 1 st adjusted running frequency of the frequency converter is changed into H1=HH-1×H0
(2) And the like, if the operating frequency of the compressor is reduced, the control temperature still keeps that the temperature is not less than St-sp2 and not more than t and not more than St + sp1, and the temperature exceeds the time t in the range1The operating frequency of the frequency converter after the 2 nd adjustment is H2=HH-2×H0
(3) And so on, if the compressor is operated at a reduced frequency,the temperature is controlled to be kept between St-sp2 and St + sp1, and the temperature exceeds the time t in the range1The nth running frequency of the frequency converter is Hn ═ HH-n×H0
(4) If the compressor is reduced in operation frequency, t is passed1Time of occurrence t>St + sp1, then Hn ═ HH-n×H0+0.5×H0The compressor operating frequency is increased by 0.5 × H0.
(5) If the compressor is controlled to have a temperature St-sp2 ≦ t ≦ St + sp1 after the frequency increase and a temperature in this range exceeding a time t1, the compressor reduces the frequency, Hn ═ HH-n×H0+0.5×H0-0.25×H0
(6) If the compressor appears Hn-HH-n×H0+0.5×H0-0.25×H0Run at variable frequency, and t>St + sp1, the frequency Hn of the compressor is HH-n×H0+0.5×H0And (5) operating.
(7) After operating at the operating frequency of (5), the compressor is operated at a frequency Hn H, with the temperature being controlled to maintain a value of St-sp2 ≦ t ≦ St + sp1H-n×H0+0.5×H0-0.25×H0And (5) operating.
(8) If the operating frequency is locked and operated at the compressor, t occurs>St + sp1, 0.25 × H for each increase in operating frequency0
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.

Claims (3)

1. A control method for a compressor of a cascade ultra-low temperature refrigerator is characterized by comprising the following steps:
setting a temperature time period of turning on the low-temperature compressor, a temperature time period of turning off the low-temperature compressor and a target control temperature time period, and turning on the low-temperature compressor when the real-time temperature t of the refrigerator is greater than the lowest temperature of the temperature time period of turning on the low-temperature compressor; when the real-time temperature t of the refrigerator is less than the highest temperature of the temperature period of closing the low-temperature compressor, closing the low-temperature compressor; when the real-time temperature t of the refrigerator is in the target control temperature period, a cycle period control strategy is adopted to control the low-temperature compressor: and the rotating speed of the low-temperature compressor is controlled by adopting a PID control algorithm, so that the real-time temperature t of the refrigerator is regulated and controlled within a target control temperature period.
2. The method for controlling the compressor of the cascade ultra-low temperature refrigerator according to claim 1, further characterized in that: the loop period control strategy mode is as follows:
setting a target temperature value St, an upper limit control deviation div1 and a lower limit control deviation div2 in the refrigerator, wherein the temperature time interval of the start-up low-temperature compressor is St + div1, the temperature time interval of the shut-down low-temperature compressor is St-div2, and the target control temperature time interval is St-div2< t < St + div 1;
and acquiring the running frequency of the compressor through a PID algorithm according to the deviation value obtained by the target temperature St in the refrigerator and the real-time temperature t of the refrigerator, transmitting the running frequency signal to the frequency converter by the controller, and adjusting the output frequency, namely the running rotating speed, of the compressor by the frequency converter so as to adjust the real-time temperature in the refrigerator.
3. The method for controlling the compressor of the cascade ultra-low temperature refrigerator according to claim 2, further characterized in that: when the real-time temperature t of the refrigerator is in the target control temperature period, namely St-sp2 is less than or equal to t is less than or equal to St + sp1, and the temperature exceeds the time t in the range1Then, starting to perform self-adjustment of the frequency of the high-temperature stage compressor, and setting the step length of the search frequency to be H0The operation frequency of the compressor is controlled to be reduced, the real-time temperature t in the refrigerator is still controlled within the range that t is more than or equal to St-sp2 and less than or equal to St + sp1, and the operation frequency of the frequency converter subjected to nth frequency reduction is Hn-HH-n×H0
If the compressor is reducing the running frequency, the real-time temperature t of the refrigerator>St + sp1, the high temperature compressor is controlled to increase the operation frequency, and if the high temperature compressor is increased in frequency, the frequency Hn is equal to HH-n×H0+0.5×H0Is carried out byHRepresenting the highest frequency if the temperature is controlledThe degree St-sp2 is less than or equal to t is less than or equal to St + sp1 and the temperature exceeds the time t in the range1Then, the frequency of the compressor is controlled continuously, when the compressor is driven by Hn ═ HH-n×H0+0.5×H0-0.25×H0And t is>St + sp1, the frequency Hn of the compressor is HH-n×H0+0.5×H0Operation, if the operating frequency is locked and operated at the compressor, t occurs>St + sp1, then the operating frequency is increased by 0.25 × H each time0Increasing the time to t1Said t is1Is a frequency detection period.
CN202010163974.7A 2020-03-10 2020-03-10 Control method for compressor of cascade ultralow-temperature refrigerator Active CN111351307B (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112254428A (en) * 2019-07-22 2021-01-22 合肥华凌股份有限公司 Food material fresh-keeping control method and device, refrigeration equipment and storage medium
CN113883819A (en) * 2021-09-30 2022-01-04 冰山松洋生物科技(大连)有限公司 Power control method and system for medical ultralow-temperature storage box
CN114198932A (en) * 2020-09-17 2022-03-18 青岛海尔生物医疗股份有限公司 Preservation box control method and preservation box

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CN1470833A (en) * 2002-07-24 2004-01-28 Lg������ʽ���� Refrigerator operation control method
CN102620519A (en) * 2012-04-13 2012-08-01 四川长虹空调有限公司 Temperature precision control method for frequency conversion refrigerator
CN102735018A (en) * 2012-06-26 2012-10-17 四川长虹电器股份有限公司 Method for controlling temperature of mechanical refrigerator in frequency conversion mode
CN102829572A (en) * 2012-09-06 2012-12-19 昆山一恒仪器有限公司 Energy-saving ultralow-temperature preservation box
JP2014031947A (en) * 2012-08-03 2014-02-20 Mitsubishi Electric Corp Refrigerator-freezer

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1470833A (en) * 2002-07-24 2004-01-28 Lg������ʽ���� Refrigerator operation control method
CN102620519A (en) * 2012-04-13 2012-08-01 四川长虹空调有限公司 Temperature precision control method for frequency conversion refrigerator
CN102735018A (en) * 2012-06-26 2012-10-17 四川长虹电器股份有限公司 Method for controlling temperature of mechanical refrigerator in frequency conversion mode
JP2014031947A (en) * 2012-08-03 2014-02-20 Mitsubishi Electric Corp Refrigerator-freezer
CN102829572A (en) * 2012-09-06 2012-12-19 昆山一恒仪器有限公司 Energy-saving ultralow-temperature preservation box

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112254428A (en) * 2019-07-22 2021-01-22 合肥华凌股份有限公司 Food material fresh-keeping control method and device, refrigeration equipment and storage medium
CN112254428B (en) * 2019-07-22 2021-12-17 合肥华凌股份有限公司 Food material fresh-keeping control method and device, refrigeration equipment and storage medium
CN114198932A (en) * 2020-09-17 2022-03-18 青岛海尔生物医疗股份有限公司 Preservation box control method and preservation box
CN114198932B (en) * 2020-09-17 2023-08-11 青岛海尔生物医疗股份有限公司 Preservation box control method and preservation box
CN113883819A (en) * 2021-09-30 2022-01-04 冰山松洋生物科技(大连)有限公司 Power control method and system for medical ultralow-temperature storage box

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