CN112747412A - Control method of magnetic suspension variable-frequency centrifugal direct-expansion air conditioning unit - Google Patents

Control method of magnetic suspension variable-frequency centrifugal direct-expansion air conditioning unit Download PDF

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Publication number
CN112747412A
CN112747412A CN201911050606.5A CN201911050606A CN112747412A CN 112747412 A CN112747412 A CN 112747412A CN 201911050606 A CN201911050606 A CN 201911050606A CN 112747412 A CN112747412 A CN 112747412A
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China
Prior art keywords
magnetic suspension
variable frequency
frequency
temperature
centrifugal compressor
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Pending
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CN201911050606.5A
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Chinese (zh)
Inventor
刘长路
赵漮
姚丽
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tsinghua Tongfang Co Ltd
Tsinghua Tongfang Artificial Environment Co Ltd
Tongfang Co Ltd
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Tsinghua Tongfang Artificial Environment Co Ltd
Tongfang Co Ltd
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Priority to CN201911050606.5A priority Critical patent/CN112747412A/en
Publication of CN112747412A publication Critical patent/CN112747412A/en
Pending legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/30—Control or safety arrangements for purposes related to the operation of the system, e.g. for safety or monitoring
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/62—Control or safety arrangements characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
    • F24F11/63—Electronic processing
    • F24F11/64—Electronic processing using pre-stored data
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/70—Control systems characterised by their outputs; Constructional details thereof
    • F24F11/72—Control systems characterised by their outputs; Constructional details thereof for controlling the supply of treated air, e.g. its pressure
    • F24F11/74—Control systems characterised by their outputs; Constructional details thereof for controlling the supply of treated air, e.g. its pressure for controlling air flow rate or air velocity
    • F24F11/77—Control systems characterised by their outputs; Constructional details thereof for controlling the supply of treated air, e.g. its pressure for controlling air flow rate or air velocity by controlling the speed of ventilators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/70—Control systems characterised by their outputs; Constructional details thereof
    • F24F11/80—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air
    • F24F11/86—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling compressors within refrigeration or heat pump circuits
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/88—Electrical aspects, e.g. circuits
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F2110/00—Control inputs relating to air properties
    • F24F2110/10—Temperature
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F2110/00—Control inputs relating to air properties
    • F24F2110/20—Humidity
    • Y—GENERAL 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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
    • Y02B30/70—Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Signal Processing (AREA)
  • Fluid Mechanics (AREA)
  • Thermal Sciences (AREA)
  • Fuzzy Systems (AREA)
  • Mathematical Physics (AREA)
  • Air Conditioning Control Device (AREA)

Abstract

A control method of a magnetic suspension variable frequency centrifugal direct expansion air conditioning unit relates to the field of refrigeration air conditioners. The control method comprises the following steps: 1) the magnetic levitation variable frequency centrifugal compressor is adjusted to operate with a small capacity. 2) According to the actual return air temperature T measured by the temperature and humidity sensoriWith set value of return air temperature Ts,iDifferential value pair magnetic suspension frequency conversion centrifugal typeThe frequency of the compressor is adjusted. Compared with the prior art, the invention not only can be quickly and flexibly adjusted according to the load change, but also can realize the high energy efficiency of ultrahigh partial load and the partial load as low as 10 percent, and has the characteristics of energy conservation, silence, comfort and relatively low maintenance cost.

Description

Control method of magnetic suspension variable-frequency centrifugal direct-expansion air conditioning unit
Technical Field
The invention relates to the field of refrigeration air conditioners, in particular to a control method of a magnetic suspension variable-frequency centrifugal direct-expansion air conditioning unit.
Background
At present, a magnetic suspension variable-frequency centrifugal direct-expansion air conditioning unit can realize stepless regulation with capacity of 2-100% due to the adoption of a direct-current variable-frequency magnetic suspension compression technology, and a direct-expansion air conditioning system combined with a fan variable-frequency technology has great energy-saving potential and application space. However, at present, the operation strategy based on the double-frequency-conversion control of the compressor and the fan is complex, the interference factors are too many, and the actual operation is difficult.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a full-frequency-conversion control method for a compressor and a fan of a magnetic suspension frequency-conversion centrifugal direct-expansion air conditioning unit. The device can be quickly and flexibly adjusted according to the load change, can realize the high energy efficiency of ultrahigh partial load and the partial load as low as 10 percent, and has the characteristics of energy conservation, silence, comfort and relatively low maintenance cost.
In order to achieve the above object, the technical solution of the present invention is implemented as follows:
a control method of a magnetic suspension variable frequency centrifugal direct expansion air conditioning unit comprises a computer controller, and a magnetic suspension variable frequency centrifugal compressor, a shell and tube condenser, an electronic expansion valve and a direct evaporation type combined air conditioning box which are connected in sequence. The direct evaporation type combined air conditioning box is internally provided with an air inlet section, a filtering section, a direct evaporation cooling section and an air supply section from bottom to top in sequence, the air supply section is internally provided with a variable frequency air feeder, and the air inlet section is internally provided with a temperature and humidity sensor. And the computer controller is respectively connected with the magnetic suspension variable-frequency centrifugal compressor, the variable-frequency air feeder and the temperature and humidity sensor. The control method of the unit comprises the following steps:
1) after the unit is started, the magnetic suspension variable frequency centrifugal compressor is adjusted to operate at a small capacity.
2) Then, the actual return air temperature T is measured by the temperature and humidity sensoriWith set value of return air temperature Ts,iDifference of (a) to the frequency of the magnetically levitated variable frequency centrifugal compressorAnd (6) carrying out adjustment. The specific adjusting steps are as follows:
a) when the difference value between the two is within the set deviation Delta T, the variable frequency blower and the magnetic suspension variable frequency centrifugal compressor are adjusted to respectively operate according to the initial given rotating speed n and the frequency f.
b) When the difference between the two is greater than the deviation set value delta T, namely the return air temperature TiThe unit firstly increases the frequency of the variable frequency blower and improves the air quantity when the unit is higher. If the frequency of the fan is not equal to the maximum value, the air quantity meets the requirement of return air temperature difference, and the variable-frequency blower is not adjusted at the moment; if the frequency of the blower reaches the upper limit, the return air temperature TiAnd if the temperature is higher than the preset temperature, the rotating speed of the magnetic suspension variable-frequency centrifugal compressor is increased, and the refrigerating capacity is increased.
c) When the difference between the two is less than the deviation set value delta T, namely the return air temperature TiWhen the magnetic suspension variable frequency centrifugal compressor is in a low position, the unit firstly reduces the rotating speed of the magnetic suspension variable frequency centrifugal compressor, and if the rotating speed of the compressor is adjusted to the lower limit, the frequency of the variable frequency air feeder is adjusted, so that the magnetic suspension variable frequency centrifugal compressor is ensured to operate at a low rotating speed under the load.
Compared with the prior art, the invention has the advantages that due to the adoption of the method, the method has the following beneficial effects:
(1) the compressor and the fan are adopted for frequency conversion control at the same time, so that the adjusting time is short, and the response speed is high.
(2) By using a single parameter, i.e. return air temperature TiThe control operation mode for adjustment is simple, and the adjustment method is rapid, stable and reliable.
(3) The compressor and the fan double-frequency-conversion control operation mode is adopted, high-energy-efficiency operation of ultrahigh partial load can be realized, and the adjusting range is wide.
The invention is further described with reference to the following figures and detailed description.
Drawings
FIG. 1 is a schematic diagram of the structure of the unit of the present invention;
FIG. 2 is a flow chart of a control method according to the present invention.
Detailed Description
Referring to fig. 1 and 2, the control method of the magnetic suspension variable frequency centrifugal direct expansion air conditioning unit comprises a computer controller 7, and a magnetic suspension variable frequency centrifugal compressor 1, a shell and tube condenser 2, an electronic expansion valve 3 and a direct evaporation type combined air conditioning box 4 which are connected in sequence. An air inlet section, a filtering section, a direct evaporative cooling section and an air supply section are sequentially arranged in the direct evaporative combined air conditioning box 4 from bottom to top, a variable frequency blower 5 is arranged in the air supply section, and a temperature and humidity sensor 6 is arranged in the air inlet section. And the computer controller 7 is respectively connected with the magnetic suspension variable frequency centrifugal compressor 1, the variable frequency blower 5 and the temperature and humidity sensor 6. The control method of the unit comprises the following steps:
1) after the unit is started, the magnetic suspension variable frequency centrifugal compressor 1 is adjusted to operate at a small capacity.
2) Then, the actual return air temperature T measured by the temperature and humidity sensor 6 is used as the basisiWith set value of return air temperature Ts,iThe difference value of (a) adjusts the frequency of the magnetically levitated variable frequency centrifugal compressor 1. The specific adjusting steps are as follows:
a) when the difference value between the two is within the set deviation Delta T, the variable frequency blower 5 and the magnetic suspension variable frequency centrifugal compressor 1 are adjusted to respectively operate according to the initial given rotating speed n and the frequency f.
b) When the difference between the two is greater than the deviation set value delta T, namely the return air temperature TiWhen the air volume is higher, the frequency of the variable frequency blower 5 is increased by the unit, so that the air volume is increased. If the frequency of the fan is not at the maximum value, the air quantity meets the requirement of the return air temperature difference, and the variable-frequency blower 5 is not adjusted at the moment; if the frequency of the blower reaches the upper limit, the return air temperature TiAnd if the temperature is higher than the preset temperature, the rotating speed of the magnetic suspension variable-frequency centrifugal compressor 1 is increased, and the refrigerating capacity is increased.
c) When the difference between the two is less than the deviation set value delta T, namely the return air temperature TiWhen the magnetic suspension variable frequency centrifugal compressor is low, the unit firstly reduces the rotating speed of the magnetic suspension variable frequency centrifugal compressor 1, and if the rotating speed of the compressor is adjusted to the lower limit, the frequency of the variable frequency blower 5 is adjusted, so that the magnetic suspension variable frequency centrifugal compressor 1 is ensured to operate at the low rotating speed under the load.
In the control method of the invention, the adjusting range of the variable frequency blower 5 is adjusted according to the return air temperature TiWith set value of return air temperature Ts,iThe difference of (a). The larger the difference is, the larger the adjustment step length of the variable frequency blower 5 is, and the adjustment time is shortened; the smaller the difference is, the smaller the adjustment step length of the variable frequency blower 5 is, and the adjustment time is prolonged.
In the control method of the invention, the rotating speed of the magnetic suspension variable-frequency centrifugal compressor 1 is adjusted according to the return air temperature TiWith set value of return air temperature Ts,iThe adjusted time is corrected according to the change rate of the return air temperature. When the temperature of return air is TiWith set value of return air temperature Ts,iWhen the difference is large, the adjusting step length is increased, and when the return air temperature T is highiWith set value of return air temperature Ts,iWhen the difference is smaller, the step size is decreased. Adjusting time correction and temperature change rate, wherein the larger the temperature change is, the faster the adjusting time is. The slower the temperature change, the slower the conditioning time.
The above examples are merely illustrative for clarity and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of the invention may be made without departing from the scope of the invention.

Claims (1)

1. A control method of a magnetic suspension variable frequency centrifugal direct expansion air conditioning unit comprises a computer controller (7), a magnetic suspension variable frequency centrifugal compressor (1), a shell and tube condenser (2), an electronic expansion valve (3) and a direct evaporation type combined air conditioning box (4) which are sequentially connected, wherein an air inlet section, a filter section, a direct evaporation cooling section and an air supply section are sequentially arranged in the direct evaporation type combined air conditioning box (4) from bottom to top, a variable frequency blower (5) is arranged in the air supply section, a temperature and humidity sensor (6) is arranged in the air inlet section, and the computer controller (7) is respectively connected with the magnetic suspension variable frequency centrifugal compressor (1), the variable frequency blower (5) and the temperature and humidity sensor (6); the control method of the unit comprises the following steps:
1) after the unit is started, firstly, the magnetic suspension variable frequency centrifugal compressor (1) is adjusted to operate at a small capacity;
2) then, the actual return air temperature T measured by the temperature and humidity sensor (6) is used as the basisiWith set value of return air temperature Ts,iThe difference value of the magnetic suspension variable frequency centrifugal compressor (1) is used for adjusting the frequency of the magnetic suspension variable frequency centrifugal compressor (1); the specific adjusting steps are as follows:
a) when the difference value between the two is within the set deviation delta T, the variable frequency blower (5) and the magnetic suspension variable frequency centrifugal compressor (1) are adjusted to respectively operate according to the initial given rotating speed n and the frequency f;
b) when the difference between the two is greater than the deviation set value delta T, namely the return air temperature TiThe unit is higher, the frequency of the variable frequency blower (5) is increased firstly, and the air volume is increased; if the frequency of the fan is not at the maximum value, the air quantity meets the requirement of return air temperature difference, and the variable-frequency blower (5) is not adjusted at the moment; if the frequency of the blower reaches the upper limit, the return air temperature TiIf the temperature is higher than the set temperature, the rotating speed of the magnetic suspension variable-frequency centrifugal compressor (1) is increased, and the refrigerating capacity is increased;
c) when the difference between the two is less than the deviation set value delta T, namely the return air temperature TiWhen the magnetic suspension variable frequency centrifugal compressor is low, the unit firstly reduces the rotating speed of the magnetic suspension variable frequency centrifugal compressor (1), and if the rotating speed of the compressor is adjusted to the lower limit, the frequency of the variable frequency blower (5) is adjusted, so that the magnetic suspension variable frequency centrifugal compressor (1) is ensured to operate at the low rotating speed under the load.
CN201911050606.5A 2019-10-31 2019-10-31 Control method of magnetic suspension variable-frequency centrifugal direct-expansion air conditioning unit Pending CN112747412A (en)

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Application Number Priority Date Filing Date Title
CN201911050606.5A CN112747412A (en) 2019-10-31 2019-10-31 Control method of magnetic suspension variable-frequency centrifugal direct-expansion air conditioning unit

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Application Number Priority Date Filing Date Title
CN201911050606.5A CN112747412A (en) 2019-10-31 2019-10-31 Control method of magnetic suspension variable-frequency centrifugal direct-expansion air conditioning unit

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CN112747412A true CN112747412A (en) 2021-05-04

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104534706A (en) * 2014-12-26 2015-04-22 克莱门特捷联制冷设备(上海)有限公司 Oil-free magnetic suspension air cooling unit and method for controlling the same
CN108375175A (en) * 2018-02-08 2018-08-07 珠海格力电器股份有限公司 air conditioning system control method and device
CN209325916U (en) * 2018-11-15 2019-08-30 同方人工环境有限公司 Direct refrigeration-type magnetic suspension convertible frequency air-conditioner unit

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104534706A (en) * 2014-12-26 2015-04-22 克莱门特捷联制冷设备(上海)有限公司 Oil-free magnetic suspension air cooling unit and method for controlling the same
CN108375175A (en) * 2018-02-08 2018-08-07 珠海格力电器股份有限公司 air conditioning system control method and device
CN209325916U (en) * 2018-11-15 2019-08-30 同方人工环境有限公司 Direct refrigeration-type magnetic suspension convertible frequency air-conditioner unit

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Application publication date: 20210504