GB2500546A - Cooling system and method for operating same - Google Patents

Cooling system and method for operating same Download PDF

Info

Publication number
GB2500546A
GB2500546A GB1312287.4A GB201312287A GB2500546A GB 2500546 A GB2500546 A GB 2500546A GB 201312287 A GB201312287 A GB 201312287A GB 2500546 A GB2500546 A GB 2500546A
Authority
GB
United Kingdom
Prior art keywords
refrigerant
cold water
condenser
refrigerant liquid
temperature
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB1312287.4A
Other versions
GB201312287D0 (en
Inventor
Junichi Ito
Yasuhiro Kashirajima
Yasuhiko Inadomi
Tomohiro Yoshida
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.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Publication of GB201312287D0 publication Critical patent/GB201312287D0/en
Publication of GB2500546A publication Critical patent/GB2500546A/en
Withdrawn legal-status Critical Current

Links

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
    • F25B49/00—Arrangement or mounting of control or safety devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D15/00—Control, e.g. regulation, of pumps, pumping installations or systems
    • F04D15/0077—Safety measures
    • F04D15/0083—Protection against sudden pressure change, e.g. check valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
    • F04D29/669—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for liquid pumps
    • 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
    • F24F11/83—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the supply of heat-exchange fluids to 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
    • 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
    • F24F11/83—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the supply of heat-exchange fluids to heat-exchangers
    • F24F11/84—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the supply of heat-exchange fluids to heat-exchangers using valves
    • 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
    • F24F11/83—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the supply of heat-exchange fluids to heat-exchangers
    • F24F11/85—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the supply of heat-exchange fluids to heat-exchangers using variable-flow pumps
    • 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
    • F24F11/89—Arrangement or mounting of control or safety devices
    • 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
    • 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
    • F25B23/00—Machines, plants or systems, with a single mode of operation not covered by groups F25B1/00 - F25B21/00, e.g. using selective radiation effect
    • F25B23/006—Machines, plants or systems, with a single mode of operation not covered by groups F25B1/00 - F25B21/00, e.g. using selective radiation effect boiling cooling systems
    • 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
    • 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
    • F25B25/00—Machines, plants or systems, using a combination of modes of operation covered by two or more of the groups F25B1/00 - F25B23/00
    • F25B25/005—Machines, plants or systems, using a combination of modes of operation covered by two or more of the groups F25B1/00 - F25B23/00 using primary and secondary systems

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Air Conditioning Control Device (AREA)
  • Other Air-Conditioning Systems (AREA)

Abstract

Provided are: an air conditioning system configured so that the air conditioning ability thereof can be controlled appropriately by preventing the cavitation of the refrigerant pump; and a method for operating the air conditioning system. The present invention is characterized in comprising: an evaporator for evaporating a refrigerant by exchanging heat with indoor air to be air conditioned; a condenser for liquefying the refrigerant gas formed in the evaporator; a refrigerant pump for delivering the refrigerant liquid formed in the condenser to the evaporator; a refrigerant liquid tank disposed between the condenser and the refrigerant pump and temporarily storing the refrigerant liquid formed in the condenser; first cold water piping for supplying cold water, which is generated by a heat source machine, to the condenser; second cold water piping for supplying the cold water, which is generated by the heat source machine, to the refrigerant liquid tank; a tank liquid temperature sensor for measuring the temperature of the refrigerant liquid within the refrigerant liquid tank; and a control unit for supplying cold water, which is required to condense the refrigerant, to the condenser and supplying cold water to the refrigerant liquid tank so that the temperature of the refrigerant liquid within the refrigerant liquid tank is lower than the temperature of evaporation calculated from the suction pressure of the refrigerant pump.

Description

DESCRIPTION
TITLE OF THE INVENTION:
COOLING SYSTEM AND METHOD FOR OPERATING SANE
TECHNICAL FIELD
[0001] The present invention relates to an air conditioning system of the type that makes a refrigerant pump circulate a refrigerant desired for an air conditioning device disposed in a room to be air-conditioned and a method of operating the air conditioning system.
BACKGROUND ART
[0002] A refrigerant forced circulation type cooling system that performs cooling by exchanging heat between cold water prepared on the primary side and a refrigerant and then circulating the heat-exchanged refrigerant by a refrigerant pump on the secondary side has been adopted so far in order to increase heat transport efficiency by latent heat transport or as a counterneasure taken in an application where circulation of cold water in a room to be air-conditioned is not. desirable. In a cooling system of the type as mentioned above, the cooling capacity is controlled by changing the operation state of the refrigerant pump or the quantity of cold water supplied thereto with load fluctuation. However, when the balance between the pressure in a refrigerant circulation system and. the temperature ol: the.refr:i.cre.ra.nt i.e lost in controli lug the cooling capacity, cavitation. may occur on the suction side of the refrIgerant pump and the performance cf the. refrigerant pump may.e. suddenly dexrad.ed. 0003]
Jnder the cir:currtstances as mentioned. abova., various technl.quc.s or or eventing occurrence of-cavita t4ot in a refrigerant pump in a refrigerant forced circulation type coc)iirI system are proposed In a controi].mnq techni gue of preven.ti.n.c occurrence of cavitation in a cooling system disclosed, for example, in Patent):)ocuuunt 1, occurrence of cavitation is prevented by making a pressure. redu.ci.r::g speed different ±rom a temperature reducing speed in a refrigerant circu i.aticn system by epwise increasinq the quantity of cold water sui:'plied thereto when a load exerted onto the system is increased and hence the qucxc. t ot c 1o vater o 101 tLretc i o e rcra
PRIOR ART DOCUMRNT
PATENT DOCUMENT
1 0 0 04 1 patent.: Document 1: Janane se Patent ?.ppl.icat:i.on Laid-Open No, 2008-2 81218 2.5 StIMN1ARY OF THE INVENTION
PROBLEM TO BE SOLVED BY THE INVENTION
(0005] However, in the system of preventing occurrence of cavitation by stepwise adjusting a speed at which the quantity of cold water supplied thereto is increased which is disclosed in the Patent Document 1, since the temperature of a refrigerant liquid in a condenser 6a is lowered with cold water so as to cope with load fluctuation as illustrated in FIG. 7, the pressure of the refrigerant in the condenser 6a may be reduced to cause a reduction in evaporating temperature of an evaporator 7a in a room to be air-conditioned. When the evaporating temperature of the evaporator 7a is reduced, the inside of the room to be air-conditioned may be excessively cooled and may not be appropriately air-conditioned and energy-saving operation may net be attained. Therefore, it becomes important to control the pressure itt the system when the room to be air-conditioned is excessively cooled in order to appropriately control the air-conditioning capacity.
(00061 In view of the above mentioned problem of related art, the present invention aims to provide an air conditioning system that prevents occurrence of cavitation in a refrigerant pump and attains appropriate control of the air condition Inc capacity and a method of operatina: the air condi.tioni.ncr system.
IEU1⁄2NS FOR 5OLVINC THE PROBLEMS [0 0u 71 in order to solve the above mentioned problem, the present invention pro \ndes an a I..r condit I onin system that includes an evaporator for vaporizing a refrigerant: by an chanqing heat between the refrigerant and air in a room to ne a.ircondi tioned, a condenser for liquefying a refrigerant gas vaporized by the evaporator, a refrigerant Li1IL zor feeding a refrigerant 1.1 qurd fl.tqie.fied by the.
condenser to the evaporator, a refrigerant liquid tank disposed me tween tile condenser and the refrigerant unt to temporarily store the refrigerant liquid liquefied by the condenser and first cold water p.Iplng for suoplying cold.
water generated from a heat source machine to the corjclerlser, and further includes second cold, water piping for supplying the cold water generated from the heat source machine to the refrigerant liquid tank, a refrigerant. liquid, temperature sans-or for measuring a temperature of the refrigerant l..Lquid in the refrigerant liquid tank an-d a control unit for controlling to supply the. cold, water dp sired for condensation of-the refrigerant gas to tne condenser, 1.0008] In the air: conditioning system, the first cold water piping is senies-connected with the second cold water piping to flow the cold water from the heat source machine to the condenser: and the. retrlQerarLt w1canc1 Lank in series.
[0009] in the sr conditiorD..nq system, the first coi.c water piping:is connected with the second cold water pi.pinq such that the cold water flows from the heat source machine to the con.denser via the refrigerant ii quid tank.
[0010] The air condit I oni.mx sys. tern further i.ncj.udes pressure sensors for t:e,asUrlng a. discharge pressure and a suction pressure of the refrigerant pump and an inverter fcr changing an operating frequency of the refrigerant pump, wherein the operating frequency of the ref.riae.ran.t pump is control led by the control unit such that a differential pressure between ti-ie ciisctharce pressure and the suction pressure has a set value, 0 0 11 The air conditioning system further includes a zero oont temoerature detection unit for detecting a zero point temperature in the room to he airconditioned anda condensate temperatu:re sensor for measuring a temperature of the refrigerant liquid liquefied by the condenser, wh-irei.n when the. temperature cf the retri.gerant liquid in a the rd rqerant. liquid tank is lower than the zero poit temperature detected by the zero point t eiapera.tu re -detection units the flow rate of the cold water into the refriqeran.t liquid tank is adjusted such that th.e temperature of the refrigerant liquid in the refrigerant liquid tan.k becomes h iqhe.r than the zero point. temperature in the.roos.n and the.t.I.ow rate of the cold water into the condenser is adjusted such. that the temperature of the cxuefi.ed ref.riqerant in the condenser cecomes hr qner than the temperature of the refrigerant liquid in the refrige rat-it Ii. quid tank by the cor.tt:roi. un:t, 1001.2] In the air ccrudrtaonxg szstem, an evaporattng temperature is calculated from the suction pressure. of the refrigerant pump and the cold water is supplied to-the refrigerant liquid tank. such that the temperature of the refr:i.geran.t liquid n ther efri.gerant I. i.quid tank becoi.nea lower than the calculated evaporating temperature by the control unit.
20-{00a.3j In order to solve the above mentioned pr.oui.em the present invention also provides a method of operating an air conci hi cut i.n.q system that inc I. ud.es an evapor:ator for vapc-rizirig are. frigerant by exchanging heat between the refrigerant and air in a room to be a.rcond.ta.oned, a.
condenser for liquefying a refrigerant gas vaporized by the evaporator, a refrigerant pump for feeding a refrigerant liquid liquefied by the condenser to the evaporator, a refrigerant liquid tank disposed between the condenser and the refrigerant pump to temporarily store the refrigerant liquid liquefied by the condenser and cold water piping for supplying cold water generated from a heat source machine to the condenser and the refrigerant liquid tank, and controls the operations of the above components by a control unit, wherein cold water desired for condensation of the refrigerant is supplied to the condenser.
EFFECT OF THE INVENTiON (0014] According to the present invention, prevention of occurrence of cavitation and energy-saving operation are promoted by appropriately controlling the air conditioning capacity of the system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [Fig. 1] FIG. 1 is a block configuration diagram of an embodiment 1 of the present invention.
(Fig. 2] FIG. 2 is a block configuration diagram of an embodiment 2 of the present invention.
(Fig. 3) FIG. 3 is a block configuration diagram of an a embodiment 3 of the present invention.
[Fig. 4] FIG. 4 Is a block configuration diagram of an embodiment 4 of the present invention.
(Fig. 5) FIG. 5 is a flowchart of an operation of S controlling the flow rate of cold water into a condenser according to an embodiment of the present invention.
(Fig. 6] FIG. 6 is a flowchart of an operation of controlling the flow rate of cold water into a refrigerant liquid tank according to an embodiment of the present invention.
(Fig. 7) FIG. 7 is a block configuration diagram of related art.
MODE FOR CARRYING OUT THE INVENTION
(0016] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
(0017] (Embodiment 1) FIG. I illustrates a block configuration diagram of an embodiment 1 of the present invention. An air conditioning system includes evaporators 21a and 2lb for vaporizing a refrigerant by exchanging heat between the refrigerant and air in a room to be air-conditioned, a condenser 10 for liquefying a refrigerant gas vaporized by the evaporators, a refrigerant pump 5 for circulating the refrigerant liquid liquefied by the condenser 10 to the evaporators 21a and 21b, a condensate temperature sensor 11 for measuring a temperature of the refrigerant liquid in the condenser 10, a refrigerant liquid tank 60 disposed between the condenser 10 and the refrigerant pump 50 to teorarily store the refrigerant liquid liquefied by the condenser 10, first cold water piping 71a for supplying cold water generated from a heat source machine 70 to the condenser 10 by a cold water pump 72 and the like.
(0018) The air conditioning system also includes a refrigerant cooling mechanism 62 for cooling the refrigerant liquid in the refrigerant liquid tank 60, second cold water piping 71b for supplying the cold water generated from the heat source machine 70 to the refrigerant cooling mechanism 62, a refrigerant liquid temperature sensor 61 for measuring a temperature of the refrigerant liquid in the refrigerant liquid tank 60, and a control unit 74 for controlling to suppiy cold water of a quantity desired for condensation of the refrigerant to the condenser 10 by the cold water pump 72 and to supply a predetermined quantity of cold water to the ref rigerant liquid tank 60 such that the temperature of the refrigerant liquid in the refrigerant liquid tank 60 becomes lower than an evaporating temperature corresponding to a inn pressure of the refrigerant pump 50.
[0019] The evaporators 2la and 21b are respectively Incorporated into cooling devices 20a and 20b toqether wi Lb fans 22a. and 22h and are disposed in. t.h.e room to be air'conditioned. The refrigerant liquid circulates in the e\rapnr.fc)r.c 22a and 21b, and hot airs 23e. and 23b in the room are blown aqanst the refrigerant, liquid by the. fans 22a and 22b to evaporate the refrigerant liquid in the devices to remove heat from ttie bJ.own hot airs, As a result, the hot airs 23a and 2$b in the room are cooled: and are blown out into t..h..e room as coot ed airs 24a and 24b.
[00201 On the other hand, a. refri.ge.r:ant ga.s gasified by being evaporated by the evaporators 21a and 2lh is sent to the condenser 10 via a. refrigerant gas r)j'e 30 and. is liquefied by heat exchange perro.rmec between ii:. and the cold water from the heat source machine 70. The licrue.fied refrigerant is temporarily stored in there frie rant tank 6.0 and is sent from. within, the tank 60 to the evaporators 21a and 2lh by the refrigerant pump 50 via a refrigerant liquid pipe 31, in the above mentioned case, the flow rate of the cold watt y ediusted such that the temperature of the refrigerant liquid in the condenser measured by the condensate temperature sensor 11 has a designed value desired for cooling in the cooling devices 20a and 20b. The adjustment is made by controlling the f low rate of the cold water in the cold water pinup 72 by the control unit 74 or by controlling the flow rate by adjusting opening of a three-way valve 73 so as not to excessively reduce the temperature of the refrigerant liquid in the condenser.
[0021] The above mentioned controlling operation is executed in accordance with an operation flow illustrated in FIG. 5, That is, after execution of the operation has been started in step (5) 101, a temperature of the 1E condensate in the condenser 10 is measured by the sensor 11 in 5102 and the temperature of the condensate is compared with a designed value desired for cooling by the cooling devices 20a and 20b so as to determine whether it is higher than the designed value in 5103. When NO (lower) in 5103, the quantity of cold water is controlled to be reduced in 5105 and the operation returns to 5102.
When YES in 5103, it is determined whether the condensate temperature is almost equal to the designed value in 5104.
When YES in 5104, execution of the operation is terminated in 5107. When NO (higher) in 5104, the quantity of the cold water is controlled to be increase-d:u 3106 arid the ODf5tOn returns to Si 02 022 1 The control unit 74 also controls to measure a tempers.ture of the refri.qera.r.Lt..1. i.qui.d in there ir.i.cerant liquid tank 50 by the refriqerant liquid temperature sensor 61 and to calculate an evaporating temperature of a suctlon part. of the refri erant pump 50 from. a suction side pressure value measured by a suction pressure sensor :io 51, Then, the control unit 74 controls to adjust the flow rate of the cold wat:.er 1±1 owinq into the refriserant liquid tank 60 such tnat the. measured temperature or the refrigerant liquid in the tank is lower than the calculated e.vaDo.ratlnq t.emoe rature ot the suction part of the refrigerant pump 50 by 1 to 2°C. This controlLing operation is executed in accordance with an operation flow I ustra ted in FTC, 6, After executlon of ti:ie operatlon has neen started in 2.0 stan (S)2 01, the temperature of the r fri gerant Ito id in the refrigerant liquid tank is measured and the evaporatino: t.emperat.ur s calculated from the pressure value on the suction side of the refrignrant, pump in 3202, Then., ] Lis de:termined whe:th the temperature of the refrigerant lio:uid in the tank is lower than the calculated evaporating temperature, for example, by about 2°C in 5203. When YES in 5203, execution of the operation it is terminated in 5207. When NO in $203, it is determined whether the temperature of the refrigerant liquid in the S tank is lower than the calculated evaporating temperature, for example, by a value more than 2°C in 5204. When YES in 5204, the quantity of cold water is controlled to be reduced in 5205 and the operation returns to 5202. When NO in 5204, the quantity of the cold water is controlled to be increased in $206 and the operation returns to 5202.
[00241 Since, the embodiment 1 is configured such that heat exchange is shared by excessively cooling the refrigerant liquid in the refrigerant liquid tank, liquefying the is refrigerant gas by the condenser and exchanging the desired amount of heat by the cooling devices as described above, it is allowed to suppress a reduction in pressure of the refrigerant in the condenser 10. Thus, it is allowed to suppress a reduction in pressure in the refrigerant circulation system to prevent the inside of the room to be air-conditioned from being excessively cooled, thereby performing the appropriate operation. In addition, it is allowed to prevent occurrence of cavitation by controlling a relation between the evaporating temperature on the suction side of the refrigerant pump 50 and the temperature of the refrigerant liquid in the refrigerant liquid tank.
(0025] (Embodiment 2) S FIG. 2 illustrates a block configuration diagram of an embodiment 2 of the present invention. The temperature of the refrigerant which has been excessively cooled in the refrigerant liquid tank 60 is controlled to be lower than the temperature of the refrigerant liquefied by the condenser 10 as described in the embodiment 1. Therefore, the embodiment 2 is configured such that cold water of a temperature which is lower than the temperature of the cold water flowing into the condenser 10 flows into the refrigerant liquid tank 60 in order to facilitate the controlling operation.
[0026] Specifically, first cold water piping 71a and second cold water piping 7Th for supplying cold water respectively to the condenser 10 and the refrigerant liquid tank 60 are series-connected with each other. The cold water is cascade-used such that the cold water from the heat source machine 70 is first supplied to the refrigerant tank 60 to be heat-exchanged with the refrigerant liquid and the cold water which has been increased in temperature by heat exchange is then supplied to the condenser 10 to be heat-changed with the refrigerant gas so as to liquefy the refrigerant in the above mentioned connection. It is allowed to efficiently distribute heat to the refrigerant liquid tank 60 and the condenser 10 with cold water and to attain energy-saving operation of the heat source machine by cascade-using the cold water in the above mentioned manner.
[0027] (Embodiment 3) FIG. 3 illustrates a block configuration diagram of an embodiment 3 of the present invention. 51 denotes the refrigerant pump suction pressure sensor for measuring the suction pressure of the refrigerant pump 50, 52 denotes a refrigerant pump discharge pressure sensor for measuring a discharge pressure of the refrigerant pump 50, and 53 denotes an inverter for changing an operating frequency of the refrigerant pump 50. The control unit 74 controls the operating frequency of the inverter 53 such that a difference between a value measured by the suction pressure sensor 51 and a value measured by the discharge pressure sensor 52 has a set value. In the embodiment 3, since a differential pressure between the suction pressure and the discharge pressure of the refrigerant pump 50 is maintained at the set value, it is allowed to suppress an increase in evaporating pressure by suppressing an increase in pressure in the refrigerant circulation system when a load is partially exerted on it and hence it.15 allowed to appropriately controi. the cOO.i.iflq capacity of the air conditionina system.
[0028] (EuthoW.ment 4) FIG. 4 illustrates a block configuration diagram of an emboda.me.nt: 4 of the present invention. In the embodj..ment 4, an:Lriroom zero point temperature detecLl.on.
unit 80 for detecting a zero point temperature of a room to he atrconditioned 26 is installed, In the above mentioned configuration, when a value detected by the zero poInt temnerature detection unit 80 is higher than a temperature of the refrigerant liquid in there friqerant liquid tank 60, the control unit. 74 controls to decrease the flow rate of cold water lnt-o the refrigerant liquid tank 60 such. that the temperature of the refrigerant liquid in the refrigerant liquid tank 50 becomes higher than the inS-room zero noint temperature. The control unit 74 controls to decrease the flow rate of the cold water such. that a temnerature of the refriqerant at an outlet of.
the condenser lobe comes higher than the set temperature of the refrigerant liquid in the refrigerant liquid tank simultaneously.
[0029] According to the embodiment 4, it is allowed to prevent generation of dew condensation by controlling the temperature of the refrigerant liquid in the refrigerant liquid tank 60 and the same effects as those attained by S the above embodiments are obtained. That is, it is allowed to prevent occurrence of cavitation while suppressing an increase in pressure in the refrigerant circulation system and energy-saving operation is allowed by cascade-using the cold water.
DESCRIPTION OF REFERENCE NUMERALS OR SYMBOLS
[0030] 10: condenser, 11 condensate temperature sensor, 2Oaf 20b: cooling device, 21a, 21b: evaporator, 22a, 22b: fan, 26: room to be air-conditioned, 30: refrigerant gas pipe, 31: refrigerant liquid pipe, 50: refrigerant pump, 51: suction pressure sensor, 52: discharge pressure sensor, 53: inverter, 60: refrigerant liquid tank, 61: refrigerant liquid temperature sensor, 62: refrigerant cooling mechanism, 70: heat source machine, 7Th: first cold water piping, 71b; second cold water piping, 72: cold water pump, 73: three-way valve, 74: control unit, 80: in-room zero point temperature detection unit.
GB1312287.4A 2011-01-11 2011-12-06 Cooling system and method for operating same Withdrawn GB2500546A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2011003357A JP2012145261A (en) 2011-01-11 2011-01-11 Air conditioning system and method for operating the same
PCT/JP2011/078219 WO2012096078A1 (en) 2011-01-11 2011-12-06 Cooling system and method for operating same

Publications (2)

Publication Number Publication Date
GB201312287D0 GB201312287D0 (en) 2013-08-21
GB2500546A true GB2500546A (en) 2013-09-25

Family

ID=46506991

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1312287.4A Withdrawn GB2500546A (en) 2011-01-11 2011-12-06 Cooling system and method for operating same

Country Status (5)

Country Link
US (1) US20130291575A1 (en)
JP (1) JP2012145261A (en)
GB (1) GB2500546A (en)
SG (1) SG191915A1 (en)
WO (1) WO2012096078A1 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2631567A1 (en) * 2012-02-24 2013-08-28 Airbus Operations GmbH Cooling system with a plurality of super-coolers
CN103438542A (en) * 2013-08-09 2013-12-11 四川长虹电器股份有限公司 Interactive intelligent air conditioning system and interaction method based on intelligent air conditioning system
CN105960567A (en) 2013-10-17 2016-09-21 开利公司 Two-phase refrigeration system
CN107035727A (en) * 2017-06-22 2017-08-11 哈尔滨广瀚新能动力有限公司 It is a kind of to prevent the device for storing liquid and its application method of ORC electricity generation system pump cavitations
CN107035726A (en) * 2017-06-22 2017-08-11 哈尔滨广瀚新能动力有限公司 It is a kind of to prevent the protector and its application method of ORC electricity generation system pump cavitations
US11785750B2 (en) * 2021-06-28 2023-10-10 Baidu Usa Llc Two-phase coolant distribution architecture

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07113561A (en) * 1993-10-18 1995-05-02 N T T Facilities:Kk Heat transporting apparatus
JP2002122363A (en) * 2000-10-13 2002-04-26 Mitsubishi Electric Corp Refrigerating apparatus
JP2004169942A (en) * 2002-11-18 2004-06-17 Ntt Power & Building Facilities Inc Air conditioning system
JP2004169941A (en) * 2002-11-18 2004-06-17 Ntt Power & Building Facilities Inc All year cooling type air conditioner
JP2007155315A (en) * 2005-11-08 2007-06-21 Toyo Eng Works Ltd Natural refrigerant cooling system
JP2008281218A (en) * 2007-05-08 2008-11-20 Ntt Facilities Inc Air conditioning system and control method for it
JP2009036506A (en) * 2007-07-09 2009-02-19 Ntt Facilities Inc Air-conditioning system and its operating method

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07113561A (en) * 1993-10-18 1995-05-02 N T T Facilities:Kk Heat transporting apparatus
JP2002122363A (en) * 2000-10-13 2002-04-26 Mitsubishi Electric Corp Refrigerating apparatus
JP2004169942A (en) * 2002-11-18 2004-06-17 Ntt Power & Building Facilities Inc Air conditioning system
JP2004169941A (en) * 2002-11-18 2004-06-17 Ntt Power & Building Facilities Inc All year cooling type air conditioner
JP2007155315A (en) * 2005-11-08 2007-06-21 Toyo Eng Works Ltd Natural refrigerant cooling system
JP2008281218A (en) * 2007-05-08 2008-11-20 Ntt Facilities Inc Air conditioning system and control method for it
JP2009036506A (en) * 2007-07-09 2009-02-19 Ntt Facilities Inc Air-conditioning system and its operating method

Also Published As

Publication number Publication date
GB201312287D0 (en) 2013-08-21
US20130291575A1 (en) 2013-11-07
JP2012145261A (en) 2012-08-02
SG191915A1 (en) 2013-08-30
WO2012096078A1 (en) 2012-07-19

Similar Documents

Publication Publication Date Title
CN108731187B (en) Three-pipe heat recovery multi-split air conditioner system and control method thereof
US20120006050A1 (en) Air-conditioning apparatus
GB2500546A (en) Cooling system and method for operating same
US9175889B2 (en) Heat source system and control method thereof
JP2009174800A (en) Reheating dehumidifier and air conditioner
JPH0968356A (en) Refrigerant circulating system
US11162714B2 (en) Test chamber and method
JP5514787B2 (en) Environmental test equipment
CN112797587B (en) Air conditioner control method and air conditioner system
CN112781266A (en) Enhanced vapor injection heat pump system and control method of electronic expansion valve thereof
JP2023030204A (en) Absorption refrigerator and control method for absorption refrigerator
JP4970170B2 (en) Air conditioning system and operation method thereof
JP2011007482A (en) Air conditioner
JP2006220332A (en) Composite type air conditioner
JP6213781B2 (en) External controller control method
JP2006220335A (en) Composite type air conditioner
WO2014030238A1 (en) Refrigeration device
JP2000274864A (en) Method for controlling absorption refrigerator
CN109341126B (en) Refrigerating system and control method
JP4896197B2 (en) Precision temperature control air conditioner
JPH062982A (en) Absorption room cooling/heating system and controlling method therefor
CN219534662U (en) Direct cooling and heating management system for vehicle power battery
WO2024058136A1 (en) Two-stage cascade refrigeration cycle device, and two-stage cascade refrigeration cycle device control method
WO2018020566A9 (en) Refrigeration cycle device
CN110726196B (en) Cold liquid integrated system of air conditioner

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)