WO2005116540A1 - Two phase or subcooling reheat system - Google Patents
Two phase or subcooling reheat system Download PDFInfo
- Publication number
- WO2005116540A1 WO2005116540A1 PCT/US2005/018164 US2005018164W WO2005116540A1 WO 2005116540 A1 WO2005116540 A1 WO 2005116540A1 US 2005018164 W US2005018164 W US 2005018164W WO 2005116540 A1 WO2005116540 A1 WO 2005116540A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- discharge gas
- relative humidity
- cooling stage
- gas valve
- outdoor temperature
- Prior art date
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F3/00—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems
- F24F3/12—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling
- F24F3/14—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling by humidification; by dehumidification
- F24F3/153—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling by humidification; by dehumidification with subsequent heating, i.e. with the air, given the required humidity in the central station, passing a heating element to achieve the required 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
- 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
- F25B2400/04—Refrigeration circuit bypassing means
- F25B2400/0403—Refrigeration circuit bypassing means for the condenser
-
- 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
- F25B2400/04—Refrigeration circuit bypassing means
- F25B2400/0417—Refrigeration circuit bypassing means for the subcooler
-
- 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
- F25B2600/00—Control issues
- F25B2600/25—Control of valves
- F25B2600/2501—Bypass valves
-
- 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
- F25B40/00—Subcoolers, desuperheaters or superheaters
- F25B40/02—Subcoolers
Definitions
- the invention relates to a method for increasing the flexibility of air conditioning systems that employ humidity removal .
- FIG. 1 there is illustrated an air conditioning system 10 known in the art.
- the air conditioning system 10 moves a working fluid, or refrigerant, via a continuous closed network 23 through these operational components in a continuous cycle of operation.
- the refrigerant is typically composed of Freon but may consist of any fluid, such as alcohol or the like, capable of accepting and giving up heat energy as its temperature increases and decreases and as its state changes between a gas and a liquid.
- Refrigerant enters the compressor 11 as a low pressure and temperature gas and is compressed. After compression, the refrigerant leaves the compressor 11 as a high temperature and pressure gas.
- the refrigerant moves in its gaseous state to the condenser 13.
- the received refrigerant gas decreases in energy at a constant pressure and becomes totally subcooled as it leaves the condenser.
- the liquid refrigerant proceeds to the evaporator 17.
- the refrigerant pressure is reduced by expansion device 16.
- energy is picked up from the air stream and the refrigerant leaves in a gaseous state.
- the air to be cooled is, for example, initially at about 80 degrees Fahrenheit. Such air is moved by a fan through the evaporator 17 and becomes cooled to about 50 to 55 degrees Fahrenheit or lower.
- heat exchanger 15 is provided to further subcool the refrigerant.
- the air passing over evaporator 17 exhibits more in latent and sensible cooling with the heat exchanger energized.
- the energy removed from the refrigerant by heat exchanger 15 is returned to the air stream after the air leaves evaporator 17.
- heat exchanger 15 energized the air leaving is at a higher dry bulb temperature (less sensible) and is low moisture centered (more latent) , than with heat exchanger 15 unenergized.
- a method for removing humidity from air comprises the steps of providing an air conditioning system comprising a continuous circuit through which a refrigerant flows from a compressor, through a condenser, through a heat exchanger, through an evaporator, and returning to the compressor, providing a bypass valve through which a portion of the refrigerant flows around the heat exchanger, providing a bypass circuit through which a portion of the refrigerant flows from a point upstream of the condenser to mix with the refrigerant at a point downstream of the condenser, providing a discharge gas valve for controlling the portion of the refrigerant flowing through the bypass circuit, measuring an outdoor temperature and a relative humidity, determining a cooling stage, and operating the bypass valve and the discharge gas valve to remove a portion of the humidity from the air based upon the outdoor temperature, the relative humidity, and the cooling stage.
- an air conditioning apparatus comprises a continuous circuit through which a refrigerant flows from a compressor, through a condenser, through a heat exchanger, through an evaporator, and returning to the compressor, a bypass valve through which a portion of the refrigerant flows around the heat exchanger, a bypass circuit through which a portion of the refrigerant flows from a point upstream of the condenser to mix with the refrigerant at a point downstream of the condenser, a discharge gas valve for controlling the portion of the refrigerant flowing through the bypass circuit, and a control module for receiving an outdoor temperature, a relative humidity, and a return air temperature and controlling the operation of the compressor, the discharge gas valve, and the bypass valve.
- FIG. 1 A diagram of an air conditioning system known in the art.
- FIG. 2 A diagram of an air conditioning system of the present invention.
- FIG. 3 A graph of pressure vs. enthalpy of the refrigerant flow of the prior art.
- FIG. 4 A graph of pressure vs. enthalpy of the refrigerant flow of the present invention.
- FIG. 5 A diagram of an embodiment of the present invention showing the control module .
- heat exchanger 15 becomes a condenser of the 2 phase mixture entering and a subcooler of refrigerant prior to its exit from heat exchanger 15.
- FIG. 2 With reference to figure 2, there is illustrated the air conditioning system of the present invention. Most notable is the inclusion of a circuit for partially bypassing a portion of the discharge gas from entering the condenser and a discharge gas valve 19 positioned along same. When open, discharge gas valve 19 allows for a portion of the hot gas leaving the compressor to bypass the condenser 13 which can provide enhanced flexibility when dehumidification is required. Dehumidification is often required when relative humidity in the space exceeds desired values.
- gas valve 19 is a solenoid valve.
- FIG 3 there is illustrated a plot of enthalpy versus pressure of the refrigerant of a prior art system as it passes through the closed circuit of the air conditioning system 10.
- Point 4 indicates the entrance to the compressor 11. Traveling from point 4 to point 1, the refrigerant increases in pressure and energy. Moving from point 1 to point 2, the refrigerant moves through the condenser 13 and decreases in enthalpy while maintaining an approximately constant pressure. The pressure of the refrigerant is then lowered until entering the evaporator where the enthalpy increases while maintaining approximately constant pressure until returning to the compressor at point 4.
- the present invention includes a discharge gas valve 19 which, when open, allows for a portion of the hot gas leaving the compressor to bypass the condenser 13.
- the bypass gas is mixed with the liquid refrigerant exiting the condenser.
- the resultant mixture now two phase, enters the heat exchanger 15 and is condensed and subcooled.
- the addition of heat to the refrigerant in the present invention negates sensible cooling.
- the amount of refrigerant flowing through discharge gas valve 19 is controlled to yield zero sensible capacity, that is the dry bulb temperature entering the evaporator is equal to the dry bulb temperature leaving the evaporator.
- discharge gas valve 19 The decision to open, or activate, discharge gas valve 19 depends primarily upon the need for dehumidification in the space to be cooled, the outside air temperature, and the ability to perform subcooling in the heat exchanger 15.
- the air conditioning system 10 operates with discharge gas valve 19 opened to provide for bypass and with bypass valve 21 closed. If dehumidification and cooling is desired and the outside air temperature is low, one must ascertain the availability of an economizer mode whereby dampers are opened to bring in cool outside air. If an economizer is available, it is activated with discharge gas valve 19 opened to provide for bypass and with bypass valve 21 closed.
- discharge gas valve 19 is closed, the economizer is closed, and the heat exchanger 15 is operated in the subcooling mode.
- discharge gas valve 19 is closed and bypass valve 21 is open.
- cool and “warm”, it is meant that the outside air is below or above, respectively, the desired temperature or enthalpy of the air to be cooled by the air conditioning system 10.
- a method is provided for determining when to activate the compressor 11, and open and close both discharge gas valve 19 and bypass valve 21 so as to achieve desirable performance. The method by which it is determined under what instances to open and close both discharge gas valve 19 and bypass valve 21 is defined by the table which follows :
- the table above defines the compressor mode in which the air conditioning system 10 of the present invention is operated over a range of variables. These variables include the cooling stage, the outdoor temperature, the relative humidity in the space to be cooled, and the outdoor air requirement.
- the cooling stage is broken down into three scenarios. In the first cooling stage, labeled "None", there is no need for cooling as the return air temperature of the system is below a cooling setpoint.
- the cooling setpoint may be set to any desired temperature but is typically between 70°F and 80°F, preferably approximately 75°F.
- the second cooling stage covers the situation where the return air temperature is above the aforementioned cooling setpoint but below the cooling setpoint plus a differential. While the differential may be chosen to achieve a desired range within which the first cooling stage is operative, a typical differential is approximately plus or minus 3°F. Lastly, in the cooling stage labeled "Second", the return air temperature is above the cooling setpoint plus the aforementioned differential.
- the above included table shows every possible combination of a low or a high outdoor temperature combined with a low or a high relative humidity in the space to be conditioned.
- the compressor setting is determined from a combination of the cooling stage, the outdoor temperature reading and the relative humidity reading. Possible compressor settings include Off, Reheat, Standard, and Subcooling Mode. When compressor “Off” is appropriate based upon the cooling stage, outdoor temperature, and relative humidity values, it does not matter whether the discharge gas valve 19 or the solenoid 21 is open or closed and the compressor 11 is deactivated. When the compressor "Reheat” mode is determined to be appropriate, discharge gas valve 19 is opened and solenoid 21 is closed.
- Control module 51 is adapted to receive inputs comprised of the outdoor temperature, return air temperature, relative humidity and cooling stage and, based upon such inputs, to activate/deactivate the compressor 11, as well as open and close the discharge gas valve 19 and solenoid 21 so as to selectively operate the system in the modes discussed above.
- Control module 51 is any electronic, digital or analog, device adapted, for example, through suitable programming and/or software to receive inputted data and issue control signals to the solenoid 21, gas discharge valve 19 and compressor 11.
- the outdoor temperature may be either “Low” or "High” . While the values for “Low” and “High” may be defined in any manner so as to achieve the desired operation of the discharge gas valve 19 and the solenoid 21, a low outdoor temperature is typically defined to be less than 3°F below the cooling setpoint while a high outdoor temperature is similarly defined to be an outdoor temperature greater than 3°F less than the cooling setpoint.
- there are two possible relative humidity settings or variable values, specifically "Low” and "High” The actual value of relative humidity below which relative humidity is considered to be low and above which relative humidity is considered to be high may be chosen to produce a desired compressor setting.
- a low relative humidity is considered to be any relative humidity below 55% relative humidity, and, conversely, high relative humidity is considered to be relative humidity above 55% relative humidity.
- outdoor air for cooling instead of the compressor when running in an economizer mode. In such a mode, depending upon the outdoor air requirements, there may be utilized either a minimum or a maximum of outdoor air.
- the desired compressor mode of the air conditioning system 10 is determined. Once the compressor mode is established, the operative position of both the discharge gas valve 19 and the bypass valve 21 is defined.
Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2007515253A JP2008500509A (en) | 2004-05-24 | 2005-05-24 | Two-phase or supercooled reheat system |
EP05753763A EP1771691A4 (en) | 2004-05-24 | 2005-05-24 | Two phase or subcooling reheat system |
US11/496,829 US7503183B2 (en) | 2004-01-30 | 2006-07-31 | Two phase or subcooling reheat system |
HK07110191.9A HK1102189A1 (en) | 2004-05-24 | 2007-09-19 | Air conditioning apparatus and method for removing humidity |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/852,368 | 2004-05-24 | ||
US10/852,368 US7043930B2 (en) | 2004-01-30 | 2004-05-24 | Two phase or subcooling reheat system |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/852,368 Continuation US7043930B2 (en) | 2004-01-30 | 2004-05-24 | Two phase or subcooling reheat system |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/496,829 Continuation US7503183B2 (en) | 2004-01-30 | 2006-07-31 | Two phase or subcooling reheat system |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2005116540A1 true WO2005116540A1 (en) | 2005-12-08 |
Family
ID=35450974
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2005/018164 WO2005116540A1 (en) | 2004-01-30 | 2005-05-24 | Two phase or subcooling reheat system |
Country Status (5)
Country | Link |
---|---|
EP (1) | EP1771691A4 (en) |
JP (1) | JP2008500509A (en) |
CN (1) | CN100523662C (en) |
HK (1) | HK1102189A1 (en) |
WO (1) | WO2005116540A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP3171096A4 (en) * | 2014-07-16 | 2018-03-14 | Mitsubishi Electric Corporation | Refrigerating and air conditioning device |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102980335B (en) * | 2012-09-25 | 2015-06-03 | 无锡溥汇机械科技有限公司 | Variable-frequency heat exchange system |
WO2018022638A1 (en) | 2016-07-25 | 2018-02-01 | Carrier Corporation | Dehumidification system for heat pump |
CN108195007A (en) * | 2018-01-15 | 2018-06-22 | 杭州微光电子股份有限公司 | The air-conditioning system of Temperature and Humidity Control and Btu utilization |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3798920A (en) | 1972-11-02 | 1974-03-26 | Carrier Corp | Air conditioning system with provision for reheating |
US6427461B1 (en) * | 2000-05-08 | 2002-08-06 | Lennox Industries Inc. | Space conditioning system with outdoor air and refrigerant heat control of dehumidification of an enclosed space |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2961844A (en) * | 1957-05-02 | 1960-11-29 | Carrier Corp | Air conditioning system with reheating means |
US5509272A (en) * | 1991-03-08 | 1996-04-23 | Hyde; Robert E. | Apparatus for dehumidifying air in an air-conditioned environment with climate control system |
MX9603136A (en) * | 1995-08-30 | 1997-03-29 | Carrier Corp | Air conditioning system with subcooler coil and series expander devices. |
US5651258A (en) * | 1995-10-27 | 1997-07-29 | Heat Controller, Inc. | Air conditioning apparatus having subcooling and hot vapor reheat and associated methods |
JP3841039B2 (en) * | 2002-10-25 | 2006-11-01 | 株式会社デンソー | Air conditioner for vehicles |
-
2005
- 2005-05-24 CN CNB2005800165713A patent/CN100523662C/en not_active Expired - Fee Related
- 2005-05-24 EP EP05753763A patent/EP1771691A4/en not_active Withdrawn
- 2005-05-24 WO PCT/US2005/018164 patent/WO2005116540A1/en not_active Application Discontinuation
- 2005-05-24 JP JP2007515253A patent/JP2008500509A/en not_active Withdrawn
-
2007
- 2007-09-19 HK HK07110191.9A patent/HK1102189A1/en not_active IP Right Cessation
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3798920A (en) | 1972-11-02 | 1974-03-26 | Carrier Corp | Air conditioning system with provision for reheating |
US6427461B1 (en) * | 2000-05-08 | 2002-08-06 | Lennox Industries Inc. | Space conditioning system with outdoor air and refrigerant heat control of dehumidification of an enclosed space |
Non-Patent Citations (1)
Title |
---|
See also references of EP1771691A4 * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP3171096A4 (en) * | 2014-07-16 | 2018-03-14 | Mitsubishi Electric Corporation | Refrigerating and air conditioning device |
Also Published As
Publication number | Publication date |
---|---|
EP1771691A1 (en) | 2007-04-11 |
HK1102189A1 (en) | 2007-11-09 |
JP2008500509A (en) | 2008-01-10 |
CN100523662C (en) | 2009-08-05 |
CN1961186A (en) | 2007-05-09 |
EP1771691A4 (en) | 2009-09-02 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7503183B2 (en) | Two phase or subcooling reheat system | |
US6941770B1 (en) | Hybrid reheat system with performance enhancement | |
EP1801520B1 (en) | Air conditioning system | |
AU2004267299B2 (en) | Refrigeration system | |
US6212892B1 (en) | Air conditioner and heat pump with dehumidification | |
JP2004161267A (en) | Combination of cooling plant with heat pump for automobile for performing cooling, heating and dehumidification in cabin | |
US7028492B2 (en) | Hybrid dehumidication system | |
US20100307172A1 (en) | Refrigerant system with reheat refrigerant circuit | |
US20080202155A1 (en) | Closed-Loop Dehumidification Circuit For Refrigerant System | |
WO2010039385A2 (en) | Start-up for refrigerant system with hot gas reheat | |
WO2005116540A1 (en) | Two phase or subcooling reheat system | |
JP3852553B2 (en) | Air conditioner | |
CN110709648B (en) | Air conditioner | |
JP4258117B2 (en) | Air conditioner | |
JP4187008B2 (en) | Air conditioner | |
US20050166618A1 (en) | Two phase or subcooling reheat system | |
JP4270555B2 (en) | Reheat dehumidification type air conditioner | |
JP4743223B2 (en) | Air conditioner | |
JP3855623B2 (en) | Air conditioner | |
US20060064997A1 (en) | Cooling systems | |
JPH1053022A (en) | Air-conditioning device for vehicle | |
JP4063465B2 (en) | Air conditioner and multi-type air conditioner | |
US20230168013A1 (en) | Heat pump system with flash defrosting mode | |
JPH04136669A (en) | Multi-room air conditioner | |
KR100438272B1 (en) | Control system of Air conditioner |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KM KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NG NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SM SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 11496829 Country of ref document: US |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2005753763 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2007515253 Country of ref document: JP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 200580016571.3 Country of ref document: CN |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWW | Wipo information: withdrawn in national office |
Country of ref document: DE |
|
WWP | Wipo information: published in national office |
Ref document number: 11496829 Country of ref document: US |
|
WWP | Wipo information: published in national office |
Ref document number: 2005753763 Country of ref document: EP |