Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B13/00—Compression machines, plants or systems, with reversible cycle
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B1/00—Compression machines, plants or systems with non-reversible cycle
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B43/00—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B47/00—Arrangements for preventing or removing deposits or corrosion, not provided for in another subclass
  • F25B47/02—Defrosting cycles
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B47/00—Arrangements for preventing or removing deposits or corrosion, not provided for in another subclass
  • F25B47/02—Defrosting cycles
  • F25B47/022—Defrosting cycles hot gas defrosting
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
  • F25B2313/027—Compression machines, plants or systems with reversible cycle not otherwise provided for characterised by the reversing means
  • F25B2313/02741—Compression machines, plants or systems with reversible cycle not otherwise provided for characterised by the reversing means using one four-way valve
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
  • F25B2400/07—Details of compressors or related parts
  • F25B2400/075—Details of compressors or related parts with parallel compressors

Definitions

• the present disclosure relates to an air conditioning system and a controlling method thereof.
• an air conditioning system is an apparatus for heating/cooling an indoor space using a refrigerant cycle.
• the air conditioning system provides high temperature refrigerant compressed by a compressing unit to an indoor heat exchanger to heat an indoor space. Refrigerant condensed at the indoor heat exchanger expands and then is provided to an outdoor heat exchange unit. Refrigerant evaporated at the outdoor heat exchange unit flows into a compressing unit. At this point, when outdoor temperature is low, humidity contained in air is frozen on the surface of the outdoor heat exchange unit. When a large amount of frost is generated on the surface of the outdoor heat exchange unit, the heat exchange performance of the outdoor heat exchange unit is considerably reduced, and efficiency of a refrigerant cycle is considerably reduced on the whole. Therefore, a defrosting operation is performed to remove frost generated on the outdoor heat exchange unit. During the defrosting operation, refrigerant circulates in an opposite direction to the direction of a heating operation.
• Embodiments provide an air conditioner capable of performing a heating operation even while a defrosting operation is performed. [6] Embodiments also provide an air conditioner capable of reducing unpleasant feeling of consumers and preventing heating energy loss.
• an air conditioning system includes an indoor heat exchange unit which exchanges heat with indoor air, and an outdoor heat exchange unit which exchanges heat with outdoor air, where the outdoor heat exchange unit performs a defrosting operation to remove frost from the outdoor heat exchange unit while the indoor heat exchange unit simultaneously performs a heating operation to heat the indoor air.
• the air conditioning system may also include a compressing unit that discharges high temperature refrigerant, a switching unit connected to a discharge side of the compressing unit, the outdoor heat exchange unit being connected to the switching unit, an expansion unit connected to the outdoor heat exchange unit, the indoor heat exchange unit being connected to the expansion unit and the switching unit, and a bypass unit that provides the high temperature refrigerant discharged from the compressing unit to an intake side of the outdoor heat exchange unit during the defrosting operation.
• the bypass unit may be connected to a refrigerant pipe between the compressing unit and the switching unit, and may be connected to a refrigerant pipe between the switching unit and the indoor heat exchange unit.
• the air conditioning system may also include a connecting unit that provides refrigerant from a discharge side of the expansion unit to a discharge side of the outdoor heat exchange unit during the defrosting operation.
• An accumulator including a heating unit may be disposed at an intake side of the compressing unit.
• the compressing unit may include a plurality of compressors, and the bypass unit may provide refrigerant discharged from at least one of the compressors to the intake side of the outdoor heat exchange unit during the defrosting operation.
• the air conditioning system may also include a refrigerant pipe connecting the compressing unit to the switching unit, the refrigerant pipe including a valve which is closed during the defrosting operation.
• the bypass unit may include a valve and a pressure controller.
• a heating unit that heats refrigerant may be disposed at an intake side of the compressing unit.
• an air conditioning system includes a bypass unit that provides refrigerant discharged from a compressing unit to an intake side of an outdoor heat exchange unit during a defrosting operation, and a connecting unit that provides expanded refrigerant to a discharge side of the outdoor heat exchange unit during the defrosting operation.
• the bypass unit may be connected to a refrigerant pipe between a switching unit and an indoor heat exchange unit, and a refrigerant pipe between an expansion unit and the outdoor heat exchange unit.
• the connecting unit may be connected to a refrigerant pipe between an expansion unit and the outdoor heat exchange unit, and a refrigerant pipe between a switching unit and the outdoor heat exchange unit.
• the connecting unit may be connected to a refrigerant pipe between an expansion unit and the bypass unit.
• a heating unit that heats refrigerant may be disposed at an intake side of the compressing unit.
• a method for controlling an air conditioning system includes performing heat exchange with indoor air to heat the indoor air, and simultaneously defrosting an outdoor heat exchange unit when a defrosting operation is triggered.
• Defrosting the outdoor heat exchange unit may include discharging refrigerant from a compressing unit, and providing a portion of the discharged refrigerant to an intake side of the outdoor heat exchange unit via a bypass unit.
• the method may also include heating refrigerant introduced to the compressing unit.
• the defrosting operation may be triggered when the temperature of the outdoor heat exchange unit is less than a predetermined temperature.
• An indoor heat exchange unit may perform the heat exchange with the indoor air, and refrigerant discharged from the indoor heat exchange unit may be provided to a discharge side of the outdoor heat exchange unit via a connecting unit.
• Refrigerant discharged from the indoor heat exchange unit may be prevented from flowing into an intake side of the outdoor heat exchange unit.
• an outdoor heat exchange unit can be operated to remove frost even while heating an indoor space. Furthermore, since an indoor space can be heated during a defrosting operation, complaints of consumers can be resolved and heating energy loss can be prevented.
• temperature of refrigerant introduced to a compressing unit during a defrosting operation can be raised, temperature of refrigerant introduced to a compressing unit can be raised. Furthermore, since the temperature of refrigerant introduced to the compressing unit is raised, temperature of refrigerant discharged from the compressing unit is raised, so that heating efficiency and system efficiency can be enhanced on the whole.
• Fig. 1 is a circuit diagram of an air conditioning system according to an embodiment.
• FIG. 2 is a flowchart of a frost removing operating method of the air conditioning system of Fig. 1.
• Fig. 3 is a P-h line graph illustrating phase change of refrigerant while the air conditioning system of Fig. 1 operates to remove frost.
• Fig. 4 is a circuit diagram of an air conditioning system according to another embodiment.
• FIG. 5 is a flowchart of a frost removing operating method of the air conditioning system of Fig. 4.
• Fig. 6 is a P-h line graph illustrating phase change of refrigerant while the air conditioning system of Fig. 4 operates to remove frost. Best Mode for Carrying Out the Invention
• FIG. 1 is a circuit diagram of an air conditioning system according to an embodiment
• Fig. 2 is a flowchart of a frost removing operating method of the air conditioning system of Fig. 1
• Fig. 3 is a P-h line graph illustrating phase change of refrigerant while the air conditioning system of Fig. 1 operates to remove frost.
• the air conditioning system includes a compressing unit 10.
• the compressing unit 10 can include a plurality of compressors 11 and 12. At this point, the compressing unit 10 includes a main compressor 11 and a subcompressor 12. The main compressor 11 operates during all operations, and the subcompressor 12 can operate only when necessary. Also, the compressing unit 10 can consist of one compressor.
• Check valves 15 can be disposed at refrigerant pipes 111 on the discharge side of the compressing unit 10, respectively, to prevent refrigerant discharged from the compressing unit 10 from flowing backward.
• a switching unit 20 is connected to the refrigerant pipes 111 on the discharge side of the compressing unit 10. At this point, examples of the switching unit 20 may include a 4- way valve. The switching unit 20 controls a circulating direction of refrigerant.
• An indoor heat exchange unit 30 is connected to the switching unit 20.
• An expansion unit 40 is connected to the indoor heat exchange unit 30.
• Examples of the expansion unit 40 may include a linear expansion valve (LEV) and a capillary tube that expands refrigerant.
• LEV linear expansion valve
• capillary tube that expands refrigerant.
• An outdoor heat exchange unit 50 is connected to the expansion unit 40.
• the switching unit 20 is connected to the outdoor heat exchange unit 50.
• An accumulator 60 is disposed at the compressing unit 10 and a refrigerant pipe 114 on the intake side of the switching unit 20.
• the accumulator 60 provides only gas refrigerant of refrigerant introduced from the switching unit 20 to the compressing unit 10.
• the accumulator 60 can include a separate heating unit (not shown) for heating refrigerant.
• a bypass unit 110 branches off from the refrigerant pipe 111 of the compressing unit
• the bypass unit 110 can branch off from the refrigerant pipe 111 of the compressor 12 of the compressing unit 10. That is, the bypass unit 110 can branch off from the refrigerant pipe(s) 111 of one or more compressors of the plurality of compressors 11 and 12.
• the bypass unit 110 can be connected to a refrigerant pipe 112 connecting the discharge side of the expansion unit 40 and the intake side of the compressing unit 10 during a heating operation.
• the bypass unit 110 is connected between the discharge side of the expansion unit 40 and the refrigerant pipe 112 at the intake side of the outdoor heat exchange unit 50 during a heating operation.
• the bypass unit 110 includes a first valve 101.
• the first valve 101 can be disposed at each of the bypass units 110.
• Examples of the first valve 101 may include an open/close valve for opening/closing the bypass unit 110.
• the bypass unit 110 can include a pressure controller 103 for controlling the pressure of refrigerant.
• the pressure controller 103 controls the pressure of refrigerant such that refrigerant discharged from the compressing unit 10 via the bypass unit 110 has pressure similar to the pressure of refrigerant that has passed through the expansion unit 40.
• a second valve 102 can be provided at a portion of the refrigerant pipe 111 that is located between a portion branching off from the bypass unit 110 and the switching unit 20.
• the second valve 102 allows refrigerant discharged from predetermined compressors 11 and 12 to be discharged to only the bypass unit 110.
• the air conditioning system can be selectively operated in a cooling or heating mode. A heating operation will be described below.
• Refrigerant discharged from the indoor heat exchange unit 30 reaches the expansion unit 40.
• the refrigerant is expanded to low temperature and low pressure while passing through the expansion unit 40.
• the expanded refrigerant flows into the outdoor heat exchange unit 50.
• the refrigerant of the outdoor heat exchange unit 50 absorbs heat from outside air to change into a gas state.
• Refrigerant discharged from the outdoor heat exchange unit 50 flows into the switching unit 20, which performs a switching operation such that the refrigerant flows into the accumulator 60.
• the accumulator 60 allows only gas refrigerant to flow into the compressing unit 10.
• a defrosting operation for melting the frost formed on the outside heat exchange unit 50 is performed.
• the temperature of the outside heat exchange unit 50 is detected, and whether the detected temperature is less than a predetermined temperature is judged (S 12). When the detected temperature is less than the predetermined temperature, the defrosting operation is performed.
• the defrosting operation can be performed when the heating operation is performed for a predetermined time.
• the heating operating time should be set in advance in a control unit (not shown) to correspond to each outside temperature.
• refrigerant discharged from the compressing unit 10 sequentially flows through the switching unit 20, the indoor heat exchange unit 30, the expansion unit 40, and the outdoor heat exchange unit 50. At this point, high temperature refrigerant discharged from the compressing unit 10 continuously flows into the indoor heat exchange unit 30 to heat an indoor space. Also, this refrigerant flowing is substantially the same as that during a heating operation.
• the first valve 101 is opened (S 13), and the second valve 102 is closed.
• a portion of refrigerant from the compressing unit 10 flows along the bypass unit 110.
• the refrigerant flowing through the bypass unit 110 is controlled to have a predetermined pressure by the pressure controller 103.
• an amount of refrigerant flowing into the switching unit 20 can be increased by slightly opening an opening degree of the second valve 102.
• the mixed refrigerant in the refrigerant pipe 112 on the intake side of the outdoor heat exchange unit 50 has temperature considerably raised in comparison with the temperature of the refrigerant discharged from the expansion unit 40.
• the mixed refrigerant of the refrigerant pipe 112 flows into the outdoor heat exchange unit 50.
• the mixed refrigerant melts frost formed on the surface of the outdoor heat exchange unit 50.
• the refrigerant discharged from the outdoor heat exchange unit 50 has relatively higher temperature than that of the discharged refrigerant in the heating operation. Therefore, the temperature of refrigerant is raised at the intake side of the compressing unit 10, so that the performance of the air conditioning system is enhanced on the whole.
• An indoor space can be heated and simultaneously frost formed on the outdoor heat exchange unit 50 can be removed by allowing high temperature refrigerant to flow into the intake side of the outdoor heat exchange unit 50 (S 14). Therefore, a heating operation does not need to be suspended in order to perform a separate defrosting operation.
• the front removing operation means an operation where a heating operation and a defrosting operation are performed simultaneously.
• refrigerant changes along a line of C1-C2-C3-C4-C1 during the heating operation cycle, and refrigerant changes along a line of C6-C7-C3-C5-C7 during the defrosting cycle.
• a pressure at the discharge side of the compressing unit 10 becomes Cl, and a pressure at the discharge side of the expansion unit 40 becomes C2 during the heating operation cycle.
• a pressure at the discharge side of the compressing unit 10 becomes Pl.
• the pressure of the portion of the compressed refrigerant becomes C3 while it passes through the expansion unit 40.
• the bypassed refrigerant mixes with refrigerant at the exit side of the expansion unit 40, the pressure of the mixed refrigerant is raised to C3, and the temperature is also raised.
• FIG. 4 is a circuit diagram of an air conditioning system according to another embodiment
• Fig. 5 is a flowchart of a frost removing operating method of the air conditioning system of Fig. 4
• Fig. 6 is a P-h line graph illustrating phase change of refrigerant while the air conditioning system of Fig. 4 operates to remove frost.
• the air conditioning system includes a compressing unit 201 for compressing refrigerant in high pressure.
• a switching unit 202 is connected to the refrigerant discharge side of the compressing unit 201. Examples of the switching unit 202 include a 4- way valve.
• An outdoor heat exchange unit 203, an indoor heat exchange unit 205, and an accumulator 206 are connected to the switching unit 202.
• the accumulator 206 is connected to the refrigerant intake side of the compressing unit 201.
• An expansion unit 204 is installed at a refrigerant pipe connecting the outdoor heat exchange unit 203 with the indoor heat exchange unit 205. Examples of the expansion unit 204 may include an LEV and a capillary tube.
• the refrigerant pipe between the switching unit 202 and the indoor heat exchange unit 205, and the refrigerant pipe between the expansion unit 204 and the outdoor heat exchange unit 203 are connected to a bypass unit 210, which can include an open/close valve 211.
• the bypass unit 210 can be provided with a pressure controller 212.
• the pressure controller 212 reduces the pressure of refrigerant such that the pressure of the refrigerant becomes similar to that of refrigerant from the expansion unit 204 when the refrigerant discharged from the compressing unit 201 flows into the refrigerant pipe between the expansion unit 204 and the outdoor heat exchange unit 203 via the bypass unit 210.
• the refrigerant pipe between the expansion unit 204 and the outdoor heat exchange unit 203, and the refrigerant pipe between the switching unit 202 and the outdoor heat exchange unit 203 are connected to a connecting unit 220.
• the connecting unit 220 can be connected to the refrigerant pipe between the expansion unit 204 and the bypass unit 210.
• the connecting unit 220 can be provided with an open/close valve 221.
• the open/close valve 221 can be disposed at a portion where the refrigerant pipe between the expansion unit 204 and the outdoor heat exchange unit 203, and the connecting unit 220 are connected to each other.
• examples of the open/ close valve 221 may include a 3- way valve.
• the open/close valve 221 can be disposed at the connecting unit 220.
• the connecting unit 220 can be provided with a pressure controller (not shown).
• a heating unit 207 can be disposed inside the accumulator 206. At this point, the heating unit 207 heats refrigerant received in the accumulator 206.
• the air conditioning system is operated in a cooling or heating mode as refrigerant is circulated in one or the other direction.
• Refrigerant cycle during the cooling operation is opposite to that during the heating operation. Accordingly, only heating operation will be described below.
• Refrigerant condensed by the indoor heat exchange unit 205 flows into the expansion unit 204 and is expanded with low temperature and low pressure.
• the expanded refrigerant flows into the outdoor heat exchange unit 203.
• Refrigerant of the outdoor heat exchange unit 203 exchanges heat with outside air.
• the outdoor heat exchange unit 203 serves as an evaporator.
• the switching unit 202 performs a switching operation such that refrigerant introduced from the outdoor heat exchange unit 203 flows into the accumulator 206. Only gas phase refrigerant of refrigerant that has flowed into the accumulator 206 flows into the compressing unit 201. At this point, the heating unit 207 of the accumulator 206 operates to heat the refrigerant of the accumulator 206. Then, the temperature of the refrigerant introduced into the compressing unit 201 is raised, so that efficiency of the heating cycle can be enhanced.
• a defrosting operation for melting frost formed on the outdoor heat exchange unit 203 is performed when more than a predetermined amount of frost is formed on the outdoor heat exchange unit 203.
• the temperature of the outside heat exchange unit 203 is detected, and whether the detected temperature is less than a predetermined temperature is judged (S22). When the detected temperature is less than the predetermined temperature, the defrosting operation is performed.
• the defrosting operation can be performed when the heating operation is performed for a predetermined time.
• the heating operating time should be set in advance in a control unit (not shown) to correspond to each outside temperature.
• Refrigerant discharged from the indoor heat exchange unit 205 sequentially flows into the expansion unit 204.
• the valve 221 of the connecting unit 220 is switched such that refrigerant discharged from the expansion unit 204 flows to the discharge side of the outdoor heat exchange unit 203 (S25).
• the refrigerant discharged from the outside heat exchange unit 203 mixes with expanded refrigerant flowing through the connecting unit 220.
• the refrigerant expanded by the expansion unit 204 is prevented from flowing into the outside heat exchange unit 203 by the valve 221 of the connecting unit 220.
• the indoor space is heated and simultaneously frost formed on the outside heat exchange unit 203 can be removed (S 14). Therefore, a heating operation does not need to be suspended to perform a separate defrosting operation.
• the front removing operation means an operation where a heating operation and a defrosting operation are performed simultaneously.
• refrigerant that has flowed into the indoor heat exchange unit 205, of refrigerant that has passed through the compressor 201 is lowered in its temperature while it passes through a process of ⁇ .
• refrigerant bypassed by the bypass unit 210 passes through a process of ⁇ ® by the pressure controller 212, and is lowered in its pressure to the pressure at the entry of the outdoor heat exchange unit 203.
• bypassed refrigerant passes through ® ⁇ ® while it passes through the outdoor heat exchange unit 203.
• the temperature of a pipe of the outdoor heat exchange unit 203 is raised.
• frost on the outdoor heat exchange unit 203 is removed by the bypassed refrigerant.
• refrigerant that passes through the indoor heat exchange unit 205 undergoes a process of ⁇ while it passes through the expansion unit 204.
• the bypassed refrigerant and the refrigerant that has passed through the expansion unit 204 merge at the exit of the outdoor heat exchange unit 203.
• refrigerant that has passed through the outdoor heat exchange unit 203 is lowered in its temperature while it undergoes a process of ® ⁇ ®, and refrigerant that has passed through the expansion unit 204 is raised in its temperature while it undergoes a process of ⁇ ®.
• the refrigerant that has merged at the exit of the outdoor heat exchange unit 203 flows into the accumulator 206, and is heated at the heating unit 207. That is, the mixed refrigerant is overheated inside the accumulator 207 to undergo a process of ⁇ ®. After that, the refrigerant is introduced to the entry of the compressing unit 201 by the switching unit 202.
• the defrosting operation according to the present disclosure means a heating operation and a defrosting operation are performed simultaneously.
• a heating operation is performed even during a defrosting operation to reduce unpleasant feeling of a consumer, and reduce heating energy.
• the air conditioner performs a heating operation even while a defrosting operation is performed. Hence, the industrial applicability is very high.

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• 2006
  • 2006-08-03 KR KR1020060073434A patent/KR100821728B1/ko active IP Right Grant
• 2007
  • 2007-07-31 US US11/831,126 patent/US20080028773A1/en not_active Abandoned
  • 2007-08-02 WO PCT/KR2007/003719 patent/WO2008016265A1/en active Application Filing
  • 2007-08-02 EP EP07793374A patent/EP2047184A4/de not_active Withdrawn
  • 2007-08-02 CN CNA2007800289607A patent/CN101501417A/zh active Pending

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