CN113959022A - Air conditioning unit and control method thereof - Google Patents

Air conditioning unit and control method thereof Download PDF

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Publication number
CN113959022A
CN113959022A CN202111354880.9A CN202111354880A CN113959022A CN 113959022 A CN113959022 A CN 113959022A CN 202111354880 A CN202111354880 A CN 202111354880A CN 113959022 A CN113959022 A CN 113959022A
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China
Prior art keywords
temperature
heat exchange
flow path
fan
exchange flow
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CN202111354880.9A
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Chinese (zh)
Inventor
李顺意
周进
钟海玲
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Gree Electric Appliances Inc of Zhuhai
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Gree Electric Appliances Inc of Zhuhai
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Priority to CN202111354880.9A priority Critical patent/CN113959022A/en
Publication of CN113959022A publication Critical patent/CN113959022A/en
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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
    • F24F5/00—Air-conditioning systems or apparatus not covered by F24F1/00 or F24F3/00, e.g. using solar heat or combined with household units such as an oven or water heater
    • F24F5/0046—Air-conditioning systems or apparatus not covered by F24F1/00 or F24F3/00, e.g. using solar heat or combined with household units such as an oven or water heater using natural energy, e.g. solar energy, energy from the ground
    • 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
    • F24F11/41—Defrosting; Preventing freezing
    • 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
    • F24F11/50—Control or safety arrangements characterised by user interfaces or communication
    • F24F11/61—Control or safety arrangements characterised by user interfaces or communication using timers
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
    • F24F13/30—Arrangement or mounting of heat-exchangers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F2140/00—Control inputs relating to system states
    • F24F2140/20—Heat-exchange fluid temperature

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Signal Processing (AREA)
  • Human Computer Interaction (AREA)
  • Sustainable Energy (AREA)
  • Sustainable Development (AREA)
  • Physics & Mathematics (AREA)
  • Fuzzy Systems (AREA)
  • Mathematical Physics (AREA)
  • Air Conditioning Control Device (AREA)

Abstract

The present disclosure relates to an air conditioning unit and a control method thereof, wherein the air conditioning unit includes: a refrigerant circulation loop provided with an evaporator; a first heat exchanger having a first heat exchange flow path and a second heat exchange flow path; the refrigerating capacity providing passage is internally circulated with refrigerating fluid and is configured to provide refrigerating capacity for users, the refrigerating capacity providing passage passes through the evaporator to exchange heat with a refrigerant in the evaporator through the refrigerating fluid, and the refrigerating capacity providing passage is communicated with the first heat exchange flow path to form a refrigerating capacity providing loop; the natural cooling passage is internally circulated with secondary refrigerant, a second heat exchanger and a liquid pump are arranged in the natural cooling passage and communicated with the second heat exchange flow path to form a natural cooling loop, the second heat exchanger is configured to exchange heat between the secondary refrigerant and the outside and promote the heat exchange through a fan, so that the refrigerating fluid in the first heat exchange flow path is cooled through the second heat exchange flow path after the heat exchange; and the controller is configured to enable the fan to be started under the condition that the first heat exchanger meets the preset anti-freezing condition after the liquid pump is started.

Description

Air conditioning unit and control method thereof
Technical Field
The disclosure relates to the technical field of air conditioner control, in particular to an air conditioning unit and a control method thereof.
Background
In order to realize the energy-saving effect, some air conditioning units have a natural cooling function at present, and in motive seasons and transition seasons, when the outdoor temperature is lower than the indoor return air temperature, the natural cooling is started, so that the air conditioning units fully utilize heat sources in the nature, and the indoor temperature is reduced to the required temperature under the condition of not starting or partially starting the compressor, thereby reducing the operation energy consumption of the compressor.
In order to realize the natural cooling function, cold energy can be transmitted to a user side through the plate heat exchanger, but the plate heat exchanger is easy to freeze due to the low temperature of the secondary refrigerant.
Disclosure of Invention
The embodiment of the disclosure provides an air conditioning unit and a control method thereof, which can solve the problem that a heat exchanger in the air conditioning unit is easy to freeze.
According to a first aspect of the present disclosure, there is provided an air conditioning unit comprising:
a refrigerant circulation loop provided with an evaporator;
a first heat exchanger having a first heat exchange flow path and a second heat exchange flow path;
the refrigerating capacity providing passage is internally circulated with refrigerating fluid and is configured to provide refrigerating capacity for users, the refrigerating capacity providing passage passes through the evaporator to exchange heat with a refrigerant in the evaporator through the refrigerating fluid, and the refrigerating capacity providing passage is communicated with the first heat exchange flow path to form a refrigerating capacity providing loop;
the natural cooling passage is internally circulated with secondary refrigerant, a second heat exchanger and a liquid pump are arranged in the natural cooling passage and communicated with the second heat exchange flow path to form a natural cooling loop, the second heat exchanger is configured to exchange heat between the secondary refrigerant and the outside and promote the heat exchange through a fan, so that the refrigerating fluid in the first heat exchange flow path is cooled through the second heat exchange flow path after the heat exchange; and
and the controller is configured to enable the fan to be started under the condition that the first heat exchanger meets the preset anti-freezing condition after the liquid pump is started.
In some embodiments, a condenser is further disposed in the refrigerant circulation loop, and the condenser and the second heat exchanger share a fan.
In some embodiments, the air conditioning assembly further comprises:
a temperature detection part configured to detect a coolant temperature at the inlet of the second heat exchange flow path;
the preset anti-freezing condition is that the temperature of the secondary refrigerant inlet of the second heat exchange flow path is higher than the preset anti-freezing temperature of the first heat exchanger.
In some embodiments, the controller is configured to delay the liquid pump for a first predetermined time after the liquid pump is turned on, and then determine a relationship between the coolant inlet temperature of the second heat exchange flow path and a predetermined freeze protection temperature of the first heat exchanger.
In some embodiments, the controller is configured to cause the fan to turn on at a preset initial frequency.
In some embodiments, the air conditioning assembly further comprises:
a temperature detection part configured to detect a coolant temperature at the inlet of the second heat exchange flow path;
the controller is configured to enable the fan to be turned off or enable the fan and the liquid pump to be turned off under the condition that the fan is in an on state and the temperature of the secondary refrigerant inlet of the second heat exchange flow path is not higher than the preset anti-freezing temperature of the first heat exchanger.
In some embodiments, the air conditioning assembly further comprises:
a temperature detection part configured to detect a coolant temperature at the inlet of the second heat exchange flow path;
and the controller is configured to adjust the frequency of the fan according to the actual load deviation of the air conditioning unit under the condition that the fan is in an open state and the temperature of the secondary refrigerant inlet of the second heat exchange flow path is higher than the preset anti-freezing temperature of the first heat exchanger.
In some embodiments, the load deviation Δ Q is calculated as:
ΔQ＝△T*B+δ*C
the delta T is the actual refrigerating fluid temperature difference, and the delta T is the refrigerating fluid temperature actually supplied to a user-the refrigerating fluid temperature required by the user;
b is a refrigerating fluid temperature difference correction value;
delta is the actual refrigerating fluid temperature change rate;
c is the corrected value of the temperature change rate of the refrigerating fluid.
According to a second aspect of the present disclosure, there is provided a control method for an air conditioning unit based on the above embodiments, including:
the liquid pump is started to circulate the secondary refrigerant in the natural cooling loop, the secondary refrigerant exchanges heat with the outside through the second heat exchanger, and the secondary refrigerant after heat exchange cools the refrigerating fluid in the first heat exchange flow path through the second heat exchange flow path;
after the liquid pump is started, and the first heat exchanger meets the preset anti-freezing condition, the fan is started.
In some embodiments, the control method further comprises:
detecting the temperature of the secondary refrigerant at the inlet of the second heat exchange flow path;
the preset anti-freezing condition is that the temperature of the secondary refrigerant inlet of the second heat exchange flow path is higher than the preset anti-freezing temperature of the first heat exchanger.
In some embodiments, the control method further comprises:
delaying a first preset time after the liquid pump is started;
and then judging the relationship between the secondary refrigerant inlet temperature of the second heat exchange flow path and the preset anti-freezing temperature of the first heat exchanger.
In some embodiments, turning on the blower comprises:
and enabling the fan to be started according to the preset initial frequency.
In some embodiments, the control method further comprises:
detecting the temperature of the secondary refrigerant at the inlet of the second heat exchange flow path;
and under the condition that the fan is in an open state and the temperature of the secondary refrigerant inlet of the second heat exchange flow path is not higher than the preset anti-freezing temperature of the first heat exchanger, the fan is closed, or the fan and the liquid pump are both closed.
In some embodiments, the control method further comprises:
detecting the temperature of the secondary refrigerant at the inlet of the second heat exchange flow path;
and under the condition that the fan is in an open state and the temperature of the secondary refrigerant inlet of the second heat exchange flow path is higher than the preset anti-freezing temperature of the first heat exchanger, adjusting the frequency of the fan according to the actual load deviation of the air conditioning unit.
According to the air conditioning unit disclosed by the embodiment of the disclosure, after the liquid pump is started in the natural cooling mode, the continuously circulating low-temperature secondary refrigerant can exchange heat with refrigerating fluid through the first heat exchanger, the temperature of the low-temperature secondary refrigerant gradually rises, and the fan is started in a delayed manner when the temperature of the secondary refrigerant is stabilized to the condition that the first heat exchanger meets the preset anti-freezing condition, so that the risk of freezing of the first heat exchanger can be reduced, and the operation reliability of the air conditioning unit is improved on the basis of fully utilizing a natural cold source.
Drawings
The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the disclosure and together with the description serve to explain the disclosure and not to limit the disclosure. In the drawings:
FIG. 1 is a schematic diagram of some embodiments of an air conditioning pack according to the present disclosure;
FIG. 2 is a flow chart of some embodiments of the air conditioning unit control method of the present disclosure.
Description of reference numerals:
1. a compressor; 2. a condenser; 3. a throttling element; 4. an evaporator; 5. a liquid pump; 6. a second heat exchanger; 7. a fan; 8. a first heat exchanger; 81. a first heat exchange flow path; 82. a second heat exchange flow path; 9. a user; 10. a refrigerant circulation circuit; 11. a temperature detection part; 20. a cold energy supply path; 30. and naturally cooling the passage.
Detailed Description
The present disclosure is described in detail below. In the following paragraphs, different aspects of the embodiments are defined in more detail. Aspects so defined may be combined with any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature considered to be preferred or advantageous may be combined with one or more other features considered to be preferred or advantageous.
The terms "first", "second", and the like in the present disclosure are merely for convenience of description to distinguish different constituent elements having the same name, and do not denote a sequential or primary-secondary relationship.
In addition, when an element is referred to as being "on" another element, it can be directly on the other element or be indirectly on the other element with one or more intervening elements interposed therebetween. In addition, when an element is referred to as being "connected to" another element, it may be directly connected to the other element or may be indirectly connected to the other element with one or more intervening elements interposed therebetween. Hereinafter, like reference numerals denote like elements.
The description of the relative orientations and positional relationships of the indications "upper," "lower," "top," "bottom," "front," "back," "inner" and "outer" and the like are used in this disclosure for convenience in describing the disclosure, and do not indicate or imply that the indicated devices must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the scope of the disclosure.
The inventor finds that when the air conditioning unit works in the natural cooling mode, the freezing of the heat exchanger is easy to happen mainly due to the following two reasons:
firstly, the temperature of the secondary refrigerant is low, which may cause the temperature of the user 9 side to quickly drop to the freezing point, so that freezing occurs, especially the temperature of the secondary refrigerant can be further reduced after the natural cooling air conditioning unit is placed in a low-temperature environment for a long time, and after the natural cooling mode is started, the temperature of the user 9 side can be quickly reduced to the vicinity of the freezing point through the heat exchange effect of the heat exchanger, so that the heat exchanger freezes.
Secondly, because the plate heat exchanger has more flow channels and smaller volume of each channel, when the liquid flow speed is lower, local areas are easy to freeze.
After the heat exchanger freezes, not only can influence the operational reliability of heat exchanger, still can damage the heat exchanger when comparatively serious.
In order to solve the problem that the heat exchanger is easy to freeze, the inventor thinks of adopting an electric heating mode to prevent freezing, but the mode has the problems of complex assembly process and higher cost. Therefore, the inventor intends to improve the phenomenon that the heat exchanger is easy to freeze from the viewpoint of changing the control method of the air conditioning unit.
Based on the above-mentioned thinking, this disclosure provides an air conditioning unit, has the natural cooling function, for example can be for the forced air cooling screw unit of natural cooling. As shown in fig. 1, in some embodiments, an air conditioning assembly includes: a refrigerant circulation loop 10, a first heat exchanger 8, a cold energy supply passage 20, a natural cooling passage 30 and a controller. For the sake of easy recognition, the refrigerant circulation circuit 10 is indicated by a medium-thick solid line, the coldness supply passage 20 is indicated by a thinnest solid line, and the natural cooling passage 30 is indicated by a thickest solid line.
The refrigerant circulation circuit 10 circulates a refrigerant therein, and the refrigerant may be water or other refrigerants, for example. The refrigerant circulation circuit 10 is provided with an evaporator 4, and further, the refrigerant circulation circuit 10 is provided with a compressor 1, a condenser 2 and a throttling element 3, for example, the throttling element 3 may be an expansion valve and a capillary tube. The refrigerant is evaporated and absorbs heat through the evaporator 4, the formed low-temperature and low-pressure gaseous refrigerant enters the compressor 1 for compression, the discharged high-temperature and high-pressure gaseous refrigerant enters the condenser 2 for condensation and heat release to form a high-pressure liquid refrigerant, and the high-pressure liquid refrigerant is decompressed through the throttling element 3 to form a gas-liquid mixed refrigerant and enters the evaporator 4.
The first heat exchanger 8 has a first heat exchange flow path 81 and a second heat exchange flow path 82. For example, the first heat exchanger 8 may be a plate heat exchanger or an economizer, etc. The first heat exchanger 8 may include a main body portion, the first heat exchange flow path 81 and the second heat exchange flow path 82 are disposed in the main body portion, the main body portion is provided with a first inlet a, a first outlet B, a second inlet C, and a second outlet D, the first inlet a and the first outlet B are communicated with the first heat exchange flow path 81, and the second inlet C and the second outlet D are communicated with the second heat exchange flow path 82.
The cold providing path 20, through which a cooling fluid circulates inside, is configured to provide cold to the user 9, and for example, the cooling fluid may be a cooling fluid or another liquid. The cold energy providing passage 20 passes through the evaporator 4 to exchange heat with the refrigerant in the evaporator 4 through the refrigerant liquid, and the cold energy providing passage 20 is communicated with the first heat exchange flow path 81 to form a cold energy providing loop. The refrigerant in the evaporator 4 is cooled after evaporation and heat absorption, and the temperature of the refrigerating fluid in the refrigerating capacity supply circuit is reduced through heat exchange, so that refrigerating capacity required by the room of the user 9 is supplied.
The natural cooling channels 30 are configured to allow a coolant to flow therethrough, and the coolant may include an anti-freezing component due to a low temperature, for example, a substance capable of lowering the freezing point of the coolant such as ethylene glycol may be added to the coolant. The natural cooling passage 30 is provided with a second heat exchanger 6 and a liquid pump 5, and is communicated with the second heat exchange flow path 82 to form a natural cooling loop, and the second heat exchanger 6 is configured to exchange heat between the secondary refrigerant and the outside, and promote the heat exchange by the fan 7, so as to cool the refrigerant in the first heat exchange flow path 81 through the second heat exchange flow path 82 after the heat exchange.
For example, the second heat exchanger 6 may be a surface cooler disposed on the surface of the condenser 2 to exchange heat with the outside air to cool the coolant, and has a small size, easy installation, and low cost. Alternatively, the second heat exchanger 6 may also be a plate heat exchanger or the like.
And the controller is configured to enable the fan 7 to be started after the liquid pump 5 is started and the first heat exchanger 8 meets the preset anti-freezing condition. For example, the liquid pump 5 is turned on immediately after the natural cooling mode is turned on.
The air conditioning unit of this embodiment can adopt the refrigeration of natural cooling second heat exchanger 6 when ambient temperature is lower, and the natural cold source in the usable environment supplies cold for the user, has reduced the consumption, has better energy-conserving effect. Because the temperature (for example, more than 10 ℃) of the refrigerating fluid entering the first heat exchange flow path 81 of the first heat exchanger 8 through the refrigerating capacity providing passage 20 is generally higher than that of the refrigerating fluid, after the liquid pump 5 is started in a natural cooling mode, the continuously circulating low-temperature refrigerating fluid can exchange heat with the refrigerating fluid through the first heat exchanger 8, the temperature of the refrigerating fluid gradually rises, and when the temperature of the refrigerating fluid is stabilized to the condition that the first heat exchanger 8 meets the preset anti-freezing condition, the fan 7 is started in a delayed manner.
In some embodiments, a condenser 2 is further disposed in the refrigerant circulation circuit 10, and the condenser 2 and the second heat exchanger 6 share a fan 7.
As shown in fig. 1, the refrigerant circulation circuit 10 is provided with a plurality of parallel condensers 2, for example, two, three or more sets. Each group of condensers 2 can be provided with a second heat exchanger 6, and each group of condensers 2 and the second heat exchangers 6 can share a fan 7. For example, each group of condensers 2 includes two condensers 2 arranged at an included angle, and a second heat exchanger 6 can be arranged on the side wall of each of the two condensers 2 away from each other, so that the second heat exchanger 6 can exchange heat with the outside air sufficiently.
This embodiment can utilize fan 7 of condenser 2 to promote the heat exchange of second heat exchanger 6, but the natural cold source in the make full use of environment is for the user cooling, has reduced the consumption, has better energy-conserving effect.
In some embodiments, the air conditioning assembly further comprises: the temperature detection part 11 is configured to detect the temperature of the coolant at the inlet of the second heat exchange flow path 82, specifically, the temperature at the second inlet C, and can directly detect the temperature of the coolant or the temperature of the tube wall of the heat exchange tube. For example, the temperature detection means 11 may be a temperature sensor or the like. The preset anti-freezing condition is that the coolant inlet temperature of the second heat exchange flow path 82 is higher than the preset anti-freezing temperature of the first heat exchanger 8. The predetermined freeze protection temperature can be obtained by tests, for example 5 ℃.
The natural cooling air conditioning unit of this embodiment makes the fan 7 open under the circumstances that the coolant import temperature of second heat transfer flow path 82 is higher than the preset frostproofing temperature of first heat exchanger 8 through the coolant temperature of monitoring the import of second heat transfer flow path 82, can prevent that first heat exchanger 8 from freezing, improves the reliability of air conditioning unit work. In addition, the control method for starting the fan 7 by detecting the temperature can effectively prevent the first heat exchanger 8 from freezing, reduce unnecessary time for a user to wait for cooling, and is favorable for quick cooling on the basis of freezing prevention.
In some embodiments, the controller is configured to delay the liquid pump 5 for a first predetermined time after it is turned on, and then determine the relationship between the coolant inlet temperature of the second heat exchange flow path 82 and the predetermined freeze protection temperature of the first heat exchanger 8.
In the embodiment, the first preset time is delayed after the liquid pump 5 is started, so that the temperature of the secondary refrigerant in the natural cooling loop tends to be stable, and then whether the temperature of the secondary refrigerant inlet of the second heat exchange flow path 82 meets the preset anti-freezing condition is judged, and the control mode can more accurately control the starting time of the fan 7 so as to prevent the first heat exchanger 8 from freezing.
Alternatively, the preset anti-freezing condition may be that the starting time of the fan 7 is delayed by a second preset time relative to the liquid pump 5, the second preset time may be determined according to a test, the preset time is delayed after the liquid pump 5 is started, and the temperature of the coolant is increased and stabilized at the temperature for preventing the first heat exchanger 8 from freezing.
In some embodiments, the controller is configured to cause the fan 7 to turn on at a preset initial frequency. The preset initial frequency may be lower than the maximum operating frequency of the fan 7, e.g. 25Hz, in order to avoid the risk of freezing the first heat exchanger 8 by pulling down the temperature of the anti-icing liquid in a short time. For example, the subsequent repeated adjustment process can be reduced by setting the operation frequency which can meet the temperature required by the user under the normal condition.
Optionally, the fan 7 is directly operated at the maximum operating frequency when it is turned on, and then adjusted as needed.
In some embodiments, the air conditioning assembly further comprises: a temperature detecting means 11 configured to detect the temperature of the coolant at the inlet of the second heat exchange flow path 82; wherein the controller is configured to turn off the fan 7 or turn off both the fan 7 and the liquid pump 5 when the fan 7 is in an on state and the coolant inlet temperature of the second heat exchange flow path 82 is not higher than the preset anti-freezing temperature of the first heat exchanger 8.
According to the embodiment, after the fan 7 is started, the inlet temperature of the secondary refrigerant is continuously monitored, if the refrigerating operation is carried out for a period of time, the temperature of the secondary refrigerant is reduced to a value which does not meet the preset anti-freezing condition, the fan 7 is closed, or the fan 7 and the liquid pump 5 are both closed, the cold quantity absorbed by the secondary refrigerant from the outside can be reduced, and the first heat exchanger 8 is prevented from being frozen.
In some embodiments, the air conditioning assembly further comprises: a temperature detecting means 11 configured to detect the temperature of the coolant at the inlet of the second heat exchange flow path 82; wherein the controller is configured to adjust the frequency of the fan 7 according to the actual load deviation of the air conditioning unit under the condition that the fan 7 is in an open state and the coolant inlet temperature of the second heat exchange flow path 82 is higher than the preset anti-freezing temperature of the first heat exchanger 8, wherein the actual load deviation is the deviation between the actual refrigeration condition and the target demand. Here the fan 7 may be a variable frequency fan.
The embodiment can flexibly meet the actual cooling demand of the user 9 on the basis of preventing the first heat exchanger 8 from freezing, and reduces the energy waste in the refrigeration process of the air conditioning unit.
In some embodiments, the load deviation Δ Q is calculated as:
ΔQ＝△T*B+δ*C
the temperature delta T is an actual refrigerating fluid temperature difference, the actual refrigerating fluid temperature supplied to the user 9-the refrigerating fluid temperature required by the user 9, the actual refrigerating fluid temperature supplied to the user 9 fluctuates under the influence of the actual performance of the unit, and the refrigerating fluid temperature required by the user 9 can be set on a unit display, which can also be called as a refrigerating fluid setting temperature;
b is a refrigerating fluid temperature difference correction value, and the default value is 1;
delta is the actual refrigerating fluid temperature change rate and is the actual refrigerating fluid temperature change value in unit time;
c is a refrigerating fluid temperature change rate correction value, and the default value is 1.
The method for calculating the load deviation Δ Q according to this embodiment comprehensively considers the influence of the actual coolant temperature difference and the coolant temperature change rate, and increases the operating frequency of the fan 7 if the coolant temperature actually supplied to the user 9 is higher than the coolant temperature required by the user 9, and decreases the operating frequency of the fan 7 if the coolant temperature actually supplied to the user 9 is lower than the coolant temperature required by the user 9. Adjusting the operating frequency of the fan 7 in dependence of the load deviation deltaq in fact controls the amount of heat exchange between the external environment and the second heat exchanger 6. This adjustment ensures that the temperature of the coolant at the inlet of the second heat exchange flow path 82 is not reduced all the time while the refrigeration requirements of the user are met, thereby reducing the risk of freezing.
Secondly, the present disclosure provides a control method for an air conditioning unit based on the above embodiments, in some embodiments, the method includes:
the liquid pump 5 is started to circulate the secondary refrigerant in the natural cooling loop, the secondary refrigerant exchanges heat with the outside through the second heat exchanger 6, and the secondary refrigerant after heat exchange cools the refrigerating fluid in the first heat exchange flow path 81 through the second heat exchange flow path 82;
after the liquid pump 5 is started and the first heat exchanger 8 meets the preset anti-freezing condition, the fan 7 is started.
According to the embodiment, after the air conditioning unit enters the natural cooling mode and the liquid pump 5 is started, the continuously circulating low-temperature secondary refrigerant can exchange heat with refrigerating fluid through the first heat exchanger 8, the temperature of the low-temperature secondary refrigerant gradually rises, the fan 7 is started in a delayed mode when the temperature of the secondary refrigerant is stable to the condition that the first heat exchanger 8 meets the preset anti-freezing condition, compared with a control mode that the fan 7 and the liquid pump 5 are started simultaneously, the risk that the first heat exchanger 8 freezes can be reduced, and the operation reliability of the air conditioning unit is improved on the basis of fully utilizing a natural cold source.
In some embodiments, the control method of the present disclosure further includes:
detecting the temperature of the secondary refrigerant at the inlet of the second heat exchange flow path 82, wherein the step can be executed immediately after the liquid pump 5 is started, and the step is executed after the liquid pump 5 is started and delayed for a preset time;
the preset anti-freezing condition is that the coolant inlet temperature of the second heat exchange flow path 82 is higher than the preset anti-freezing temperature of the first heat exchanger 8.
The natural cooling air conditioning unit of this embodiment makes the fan 7 open under the circumstances that the coolant import temperature of second heat transfer flow path 82 is higher than the preset frostproofing temperature of first heat exchanger 8 through the coolant temperature of monitoring the import of second heat transfer flow path 82, can prevent that first heat exchanger 8 from freezing, improves the reliability of air conditioning unit work. In addition, the control method for starting the fan 7 by detecting the temperature can effectively prevent the first heat exchanger 8 from freezing, reduce unnecessary time for a user to wait for cooling, and is favorable for quick cooling on the basis of freezing prevention.
In some embodiments, the control method of the present disclosure further includes:
delaying a first preset time after the liquid pump 5 is started;
and then the relationship between the coolant inlet temperature of the second heat exchange flow path 82 and the preset antifreeze temperature of the first heat exchanger 8 is determined.
In the embodiment, the first preset time is delayed after the liquid pump 5 is started, so that the temperature of the secondary refrigerant in the natural cooling loop tends to be stable, and then whether the temperature of the secondary refrigerant inlet of the second heat exchange flow path 82 meets the preset anti-freezing condition is judged, and the control mode can more accurately control the starting time of the fan 7 so as to prevent the first heat exchanger 8 from freezing.
In some embodiments, turning on the blower 7 comprises:
the fan 7 is turned on at a preset initial frequency.
Wherein the preset initial frequency may be lower than the maximum operating frequency of the fan 7, e.g. 25Hz, in order to avoid the risk of freezing the first heat exchanger 8 when the temperature of the anti-icing liquid is pulled down in a short time. For example, the subsequent repeated adjustment process can be reduced by setting the operation frequency which can meet the temperature required by the user under the normal condition.
Optionally, the fan 7 is directly operated at the maximum operating frequency when it is turned on, and then adjusted as needed.
In some embodiments, the control method of the present disclosure further includes:
detecting the temperature of the secondary refrigerant at the inlet of the second heat exchange flow path 82;
and under the condition that the fan 7 is in an open state and the temperature of the secondary refrigerant inlet of the second heat exchange flow path 82 is not higher than the preset anti-freezing temperature of the first heat exchanger 8, closing the fan 7 or closing both the fan 7 and the liquid pump 5.
According to the embodiment, after the fan 7 is started, the inlet temperature of the secondary refrigerant is continuously monitored, if the refrigerating operation is carried out for a period of time, the temperature of the secondary refrigerant is reduced to a value which does not meet the preset anti-freezing condition, the fan 7 is closed, or the fan 7 and the liquid pump 5 are both closed, the cold quantity absorbed by the secondary refrigerant from the outside can be reduced, and the first heat exchanger 8 is prevented from being frozen.
In some embodiments, the control method of the present disclosure further includes:
detecting the temperature of the secondary refrigerant at the inlet of the second heat exchange flow path 82;
and under the condition that the fan 7 is in an open state and the temperature of the secondary refrigerant inlet of the second heat exchange flow path 82 is higher than the preset anti-freezing temperature of the first heat exchanger 8, adjusting the frequency of the fan 7 according to the actual load deviation of the air conditioning unit.
Wherein the actual load deviation is a deviation between the actual refrigeration condition and the target demand.
The embodiment can flexibly meet the actual cooling demand of the user 9 on the basis of preventing the first heat exchanger 8 from freezing, and reduces the energy waste in the refrigeration process of the air conditioning unit.
The working principle of the air conditioning assembly of the present disclosure will be explained below by a specific embodiment.
After the air conditioning unit is started and enters the natural cooling mode, as shown in fig. 2, the following steps are performed:
step 101, starting the liquid pump 5 immediately;
step 102, after the liquid pump 5 operates for a first preset time A, monitoring the temperature Tsin of the secondary refrigerant at the inlet of the second heat exchange flow path 82; the first preset time A is obtained through experimental tests after the temperature of the refrigerating medium in the natural cooling loop is stabilized, and for example, the time A is 2 min.
And 103, judging whether the Tsin is higher than a preset anti-freezing temperature Td of the first heat exchanger 8 (for example, the Td is 5 ℃), if so, executing a step 104, and otherwise, keeping the fan 7 off.
And 104, enabling the fan 7 to be started according to a preset initial frequency f (for example, f is 25 Hz).
Step 105, judging whether the refrigerating medium temperature Tsin at the inlet of the second heat exchange flow path 82 is higher than the refrigerating medium temperature Tsin at the inlet of the second heat exchange flow path 82 again, if not, executing step 106, and if so, executing step 107;
step 106, immediately turning off the fan 7, or turning off the fan 7 and the liquid pump 5 at the same time;
and step 107, adjusting the operating frequency of the fan 7 according to the actual load deviation delta Q. The calculation method of the load deviation Δ Q may use the formula given above.
The air conditioning unit and the control method thereof provided by the present disclosure are described in detail above. The principles and embodiments of the present disclosure are explained herein using specific examples, which are set forth only to help understand the method and its core ideas of the present disclosure. It should be noted that, for those skilled in the art, it is possible to make several improvements and modifications to the present disclosure without departing from the principle of the present disclosure, and such improvements and modifications also fall within the scope of the claims of the present disclosure.

Claims (14)

1. An air conditioning assembly, comprising:
a refrigerant circulation circuit (10) provided with an evaporator (4);
a first heat exchanger (8) having a first heat exchange flow path (81) and a second heat exchange flow path (82);
the refrigerating capacity providing passage (20) is internally circulated with refrigerating fluid and is configured to provide refrigerating capacity for a user (9), the refrigerating capacity providing passage (20) passes through the evaporator (4) to exchange heat with a refrigerant in the evaporator (4) through the refrigerating fluid, and the refrigerating capacity providing passage (20) is communicated with the first heat exchange flow path (81) to form a refrigerating capacity providing loop;
the natural cooling passage (30) is internally circulated with refrigerating medium, a second heat exchanger (6) and a liquid pump (5) are arranged in the natural cooling passage (30) and communicated with the second heat exchange flow path (82) to form a natural cooling loop, the second heat exchanger (6) is configured to exchange heat between the refrigerating medium and the outside and promote the heat exchange through a fan (7), so that the refrigerating liquid in the first heat exchange flow path (81) is cooled through the second heat exchange flow path (82) after the heat exchange; and
a controller configured to turn on the fan (7) after the liquid pump (5) is turned on and in a case where the first heat exchanger (8) satisfies a preset freeze protection condition.
2. Air conditioning unit according to claim 1, characterized in that a condenser (2) is further provided in the refrigerant circulation circuit (10), and the fan (7) is shared by the condenser (2) and the second heat exchanger (6).
3. The air conditioning assembly as set forth in claim 1, further comprising:
a temperature detection means (11) configured to detect a coolant temperature at an inlet of the second heat exchange flow path (82);
the preset anti-freezing condition is that the temperature of a secondary refrigerant inlet of the second heat exchange flow path (82) is higher than the preset anti-freezing temperature of the first heat exchanger (8).
4. Air conditioning assembly according to claim 3, wherein the controller is configured to delay the liquid pump (5) for a first predetermined time after it is switched on and to determine the relationship between the coolant inlet temperature of the second heat exchange flow path (82) and the predetermined freeze protection temperature of the first heat exchanger (8).
5. Air conditioning assembly according to claim 1, wherein the controller is configured to cause the fan (7) to be turned on at a preset initial frequency.
6. An air conditioning unit according to any of claims 1 to 5, further comprising:
a temperature detection means (11) configured to detect a coolant temperature at an inlet of the second heat exchange flow path (82);
wherein the controller is configured to turn off the fan (7) or turn off both the fan (7) and the liquid pump (5) when the fan (7) is in an on state and the coolant inlet temperature of the second heat exchange flow path (82) is not higher than the preset anti-freezing temperature of the first heat exchanger (8).
7. An air conditioning unit according to any of claims 1 to 5, further comprising:
a temperature detection means (11) configured to detect a coolant temperature at an inlet of the second heat exchange flow path (82);
wherein the controller is configured to adjust the frequency of the fan (7) according to the actual load deviation of the air conditioning unit under the condition that the fan (7) is in an open state and the coolant inlet temperature of the second heat exchange flow path (82) is higher than the preset anti-freezing temperature of the first heat exchanger (8).
8. Air conditioning assembly according to claim 7, characterized in that the load deviation Δ Q is calculated by the formula:
ΔQ＝△T*B+δ*C
wherein, the delta T is the actual refrigerating fluid temperature difference, and the delta T is the refrigerating fluid temperature actually supplied to the user (9) -the refrigerating fluid temperature required by the user (9);
b is a refrigerating fluid temperature difference correction value;
delta is the actual refrigerating fluid temperature change rate;
c is the corrected value of the temperature change rate of the refrigerating fluid.
9. A control method of an air conditioning unit based on any one of claims 1 to 8 is characterized by comprising the following steps:
the liquid pump (5) is started, the secondary refrigerant in the natural cooling loop circulates and exchanges heat with the outside through the second heat exchanger (6), and the secondary refrigerant after heat exchange cools the refrigerating fluid in the first heat exchange flow path (81) through the second heat exchange flow path (82);
and after the liquid pump (5) is started, and under the condition that the first heat exchanger (8) meets the preset anti-freezing condition, the fan (7) is started.
10. The control method according to claim 9, characterized by further comprising:
detecting the temperature of the secondary refrigerant at the inlet of the second heat exchange flow path (82);
the preset anti-freezing condition is that the temperature of a secondary refrigerant inlet of the second heat exchange flow path (82) is higher than the preset anti-freezing temperature of the first heat exchanger (8).
11. The control method according to claim 10, characterized by further comprising:
delaying a first preset time after the liquid pump (5) is started;
and then judging the relation between the secondary refrigerant inlet temperature of the second heat exchange flow path (82) and the preset anti-freezing temperature of the first heat exchanger (8).
12. The control method according to claim 9, wherein turning on the fan (7) comprises:
and enabling the fan (7) to be started according to a preset initial frequency.
13. The control method according to any one of claims 9 to 12, characterized by further comprising:
detecting the temperature of the secondary refrigerant at the inlet of the second heat exchange flow path (82);
and when the fan (7) is in an open state and the temperature of the secondary refrigerant inlet of the second heat exchange flow path (82) is not higher than the preset anti-freezing temperature of the first heat exchanger (8), the fan (7) is turned off, or both the fan (7) and the liquid pump (5) are turned off.
14. The control method according to any one of claims 9 to 12, characterized by further comprising:
detecting the temperature of the secondary refrigerant at the inlet of the second heat exchange flow path (82);
and under the condition that the fan (7) is in an open state and the secondary refrigerant inlet temperature of the second heat exchange flow path (82) is higher than the preset anti-freezing temperature of the first heat exchanger (8), adjusting the frequency of the fan (7) according to the actual load deviation of the air conditioning unit.
CN202111354880.9A 2021-11-16 2021-11-16 Air conditioning unit and control method thereof Pending CN113959022A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202111354880.9A CN113959022A (en) 2021-11-16 2021-11-16 Air conditioning unit and control method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202111354880.9A CN113959022A (en) 2021-11-16 2021-11-16 Air conditioning unit and control method thereof

Publications (1)

Publication Number Publication Date
CN113959022A true CN113959022A (en) 2022-01-21

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Family Applications (1)

Application Number Title Priority Date Filing Date
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Country Status (1)

Country Link
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