Economizing air conditioning system of increased efficiency of heat transfer selectively from liquid coolant or refrigerant to air

• US 4,567,733 A
• Filed: 10/05/1983
• Issued: 02/04/1986
• Est. Priority Date: 10/05/1983
• Status: Expired due to Fees

• Current Assignee: IPAC 2000 Inc.
• Original Assignee: Hirose Company Limited
• Inventors: Mecozzi, Walter P.
• Primary Examiner(s): Tapolcai, William E.
• Application Number:
  US06/539,078
• Time in Patent Office: 853 Days
• Field of Search: 62/332, 62/175, 165/140
• US Class Current: 62/175
• CPC Class Codes: F24F 13/30 Arrangement or mounting of heat-exchangers
• CPC Class Codes: F24F 5/0007 cooling apparatus specially adapted for use in air-conditioning F24F5/0046 takes precedence
• CPC Class Codes: F25B 1/00 Compression machines, plants or systems with non-reversible cycle F25B3/00, F25B5/00, F25B6/00, F25B7/00, F25B9/00 take precedence
• CPC Class Codes: F25B 2400/06 Several compression cycles arranged in parallel
• CPC Class Codes: F25B 49/027 Condenser control arrangements
• CPC Class Codes: F25D 16/00 Devices using a combination of a cooling mode associated with refrigerating machinery with a cooling mode not associated with refrigerating machinery

Abstract

An air conditioning system which incorporates evaporator coils for extracting heat from air with a liquefiable gas refrigerant, and cooling coils containing a liquid coolant, such as an aqueous ethylene glycol solution, that has been cooled by cold outside air, includes such coils joined in heat transfer relationship to a multiplicity of common heat transfer fins. Due to the improved heat transfer because of a larger fin area transferring heat from either the refrigerant-containing coils or the coolant-containing coils when either refrigerant or coolant is passed through its coils, more coolant coils can be joined to the fins, so that more effective air conditioning is obtainable when the air conditioning system is in the economizing mode (with the compressor being turned off and the cooled liquid coolant being circulated through its cooling coils). Further improvements in the structure and efficiency of the air conditioning system are obtainable when dual such systems are employed in conjunction, with the liquid coolant being cooled in a single heat exchanger by outside air and being circulatable through either or both sets of cooling coils of the component system and through either or both condensers for the refrigerant, to condense the refrigerant.

Claims

1. A dual air conditioning apparatus which comprises a pair of separate circulating systems for a liquefiable gas refrigerant that is cooled by compression, condensation and evaporation, and for a liquid coolant that is cooled by cold outside air, each of which separate circulating systems includes different air cooling coils through which the respective refrigerant and liquid coolant pass, means for preventing passing of liquefiable gas refrigerant and liquid coolant through the respective cooling coils at the same time, and a multiplicity of heat transfer fins, joined to both such air cooling coils, and adapted selectively to transfer heat to circulating fluids in such coils from air to be cooled by the air conditioning apparatus, such pair of separate circulating systems being incorporated together so that both such systems can be used simultaneously to cool the air by the refrigerant or liquid coolant therein or by either such system being so employed, and which dual air conditioning apparatus comprises a single heat exchanger for cooling circulating liquid coolant by cold outside air, and means for circulating said liquid coolant through either or both of the sets of coolant-containing cooling coils of the component systems.

2. An apparatus according to claim 1 wherein the liquid coolant is aqueous solution of ethylene glycol.

3. An apparatus according to claim 2 which comprises sets of a plurality of multiple pass cooling coils containing refrigerant and of a plurality of multiple pass cooling coils containing coolant, and the multiple pass refrigerant-containing coils alternate with the multiple pass coolant-containing coils of the sets where they are joined to the heat transfer fins so as to improve the heat transfer efficiency when either refrigerant or coolant is circulated through its cooling coils.

4. A dual air conditioning apparatus which comprises a pair of separate circulating systems for a liquefiable gas refrigerant that is cooled by compression, condensation and evaporation, and for a liquid aqueous ethylene glycol coolant that is cooled by cold outside air, each of which separate circulating systems includes different air cooling coils through which the respective refrigerant and liquid aqueous ethylene glycol coolant pass, means for preventing passing of liquefiable gas refrigerant and liquid aqueous ehtylene glycol coolant through the respective cooling coils at the same time, and a multiplicity of heat transfer fins, joined to both such air cooling coils, and adapted selectively to transfer heat to circulating fluids in such coils from air to be cooled by the air conditioning apparatus, such pair of separate circulating systems being incorporated together so that both such systems can be used simultaneously to cool the air by the refrigerant or liquid coolant therein or by either such system being so employed, and which dual air conditioning apparatus comprises a single heat exchanger for cooling circulating liquid aqueous ethylene glycol coolant by cold outside air, means for circulating said coolant through either or both of sets of coolant-containing cooling coils of the component systems, and means for circulating said coolant through the condensers of either or both of the component systems to condense refrigerant therein.

5. A dual air conditioning apparatus which comprises a pair of separate circulating systems for a liquefiable gas refrigerant that is cooled by compression, condensation and evaporation, and for a liquid aqueous ethylene glycol coolant that is cooled by cold outside air, each of which separate circulating systems includes different air cooling coils through which the respective refrigerant and liquid aqueous ethylene glycol coolant pass, means for preventing passing of liquefiable gas refrigerant and liquid aqueous ethylene glycol coolant through the respective cooling coils at the same time, and a multiplicity of heat transfer fins, joined to both such air cooling coils and adapted selectively to transfer heat to circulating fluids in such coils from air to be cooled by the air conditioning apparatus, which cooling coils are in sets of a plurality of multiple pass cooling coils containing refrigerant and a plurality of multiple pass cooling coils containing liquids aqueous ethylene glycol coolant, both of which sets of cooling coils make multiple passes through the multiplicity of heat transfer fins, through which heat is transferred from air being cooled to circulating fluid in such coils, which multiple pass refrigerant-containing cooling coils are substantially cylindrical and alternate with multiple pass coolant-containing coils of the sets at locations where the coils are joined to heat transfer fins, which are substantially rectangular and elongated, so as to improve the heat transfer efficiency when either refrigerant or coolant is circulated through its coolant coils, and wherein the ratio of the number of coolant-containing coolant coils to refrigerant-containing cooling coils is within the range of 1.3 to 1.7, with the tubes of the cooling coils being located in planes which are at an angle of 15°

to 35°

to the transverse axis of the rectangular fins, such pair of separate circulating systems being incorporated together so that both such systems can be used simultaneously to cool the air by the refrigerant or liquid coolant therein or by either such system being so employed, with the same coolant being circulatable through the coolant-containing sets of cooling coils of either or both of the component systems and with the same coolant being circulatable through the condensers of either or both of the component systems to condense the refrigerant therein, and which dual air conditioning apparatus comprises a single heat exchanger for cooling circulating aqueous ethylene glycol coolant by cold outside air and means for circulating said coolant through either or both of the sets of coolant-containing coils of the component systems.

6. A dual air conditioning apparatus according to claim 5 wherein the aqueous ethylene glycol includes sufficient ethylene glycol to prevent freezing at a temperature of -30°

C., the refrigerant is a chlorofluoro lower hydrocarbon, the cooling coils are of copper and the fins are of aluminum.