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
  • F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
  • F25B9/14—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the cycle used, e.g. Stirling 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
  • F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point

Definitions

• the invention relates to a heating and cooling machine working according to a regenerative gas cycle process with at least two pistons, which separate at least three process spaces with the interposition of at least one heat exchanger and at least one regenerator connected in series therewith.
• Heating and cooling machines operating according to a regenerative gas cycle process for example the Stirling or Vuilleumier cycle process
• a regenerative gas cycle process for example the Stirling or Vuilleumier cycle process
• Such machines have two pistons which are linearly movable in a pressure-tight housing and which together limit a warm working volume and of which one piston in the housing limits a hot, heat-loaded working volume and the other piston limits a cold working volume, the three working volumes being interconnected with the interposition of regenerators and heat exchangers and a drive and / or a Control for the pistons is provided.
• the heating and cooling machines which operate according to a regenerative gas cycle process and which are used for heating and air conditioning buildings and vehicles and are equipped with a heat exchanger operated by the atmospheric air and operated as a heat source, there is a risk that at air temperatures around the Freezing point and at high air humidity of the air heat exchanger freezes. In this case, the continued operation of the machine also freezes the cold heat exchanger of the machine. This risk of freezing also exists if there are faults in the cold cycle of the machine, for example due to a failure of the circulation pump.
• the invention is based on the object of providing a heating and cooling machine which operates according to a regenerative gas circuit process and in which the risk of freezing of the cold heat exchanger is eliminated in an energetically sensible manner using structurally and technically simple means.
• the solution to this problem by the invention is characterized in that at least one of the regenerators assigned to the cold process space is provided with at least one bypass containing a control valve for changing the amount of heat transferred via the cold heat exchanger circuit between the process gas and the environment.
• the bypass valve is opened for a limited time when icing occurs on the air heat exchanger, so that no heat is drawn from and removed from the process gas in the regenerator bypassed by the bypass In this way, the cold heat exchanger arranged in the machine is brought to a temperature above the freezing point by the amount of heat coming from the warm process space, which simultaneously de-ices the air heat exchanger. Even if the circulation pump in the circuit belonging to the cold heat exchanger fails, freezing of the cold heat exchanger is avoided in this way even when the machine is running.
• the bypass line is designed in the form of a through opening in the regenerator, which is closed at both ends during normal operation of the machine. This results in a dead space-free design of this regenerator.
• bypass line is closed by a plunger which can be moved against the force of a return spring via an electromagnet.
• Figure 1 is a schematic representation of a heating and cooling machine
• FIG. 2 shows a longitudinal section through an embodiment of a regenerator provided with a bypass
• the heating and cooling machine shown schematically in FIG. 1 comprises a pressure-tight housing 1, in which a hot piston 2 and a cold piston 3 are arranged so as to be linearly movable.
• the hot piston 2 limits a hot working volume 4, to which heat is supplied, for example through a gas-heated combustion chamber 5.
• the cold piston 3 limits a cold working volume 6.
• Both pistons 2 and 3 limit a warm working volume 7.
• For the synchronized Movement of the pistons 2 and 3 is provided in the exemplary embodiment of a gear 8 which is connected to the cold piston 3 via a hollow piston rod 9 and to the hot piston 2 via a further piston rod 10.
• a regenerator 11 or 12 is arranged between the hot working volume 4 and the warm working volume 7 as well as between the warm working volume 7 and the cold working volume 6.
• the warm working volume 7 is still a warm heat exchanger 14 orders, which is connected in series with the regenerator 1 1 and, like this, is flowed through by the process gas. From this warm heat exchanger 13, heat is emitted in a closed circuit via a circulating pump 13a to a heat exchanger designed, for example, as a heater 14.
• the cold working volume 6 is also associated with a cold heat exchanger 15 connected in series with the regenerator 12 and through which process gas flows, and which is arranged with an air heat exchanger 16 in a closed circuit.
• a circulation pump 15 a is located in this circuit.
• the regenerator 12 assigned to the cold working volume 6 is provided with a bypass 17 in which a bypass valve 17a is arranged.
• this bypass valve 17a is closed, so that the bypass 17 has no influence on the heating and cooling machine operating according to a regenerative gas cycle process.
• the air heat exchanger 17 extracts heat from the atmospheric air, there is the risk that this air heat exchanger 16 freezes at air temperatures around the freezing point and at high atmospheric humidity.
• the cold heat exchanger 15 would also freeze in the machine if the machine were to continue operating. This would not only impair the gas cycle process, but would also result in such a sharp drop in temperature in the cold working volume 7, so that there is a risk of the machine being destroyed. This danger also arises if, for example, the heat exchange in the cold heat exchanger 15 is impeded by a fault in the circulation pump 15a.
• the bypass valve 17a is opened at least for a limited time. Due to the lower flow resistance, the process gas bypasses the regenerator 12 through the bypass 17, so that no heat is withdrawn from the process gas in the regenerator 12. Since the cold heat exchanger 15 is connected in series to the regenerator 12, the cold heat exchanger 15 is replaced by the warm one Working volume 7 brought or kept coming amount of heat at a temperature above freezing.
• FIG. 2 shows an embodiment of the regenerator 12 in a longitudinal section.
• the regenerator 12 is connected to the cold working volume 6 of the machine via an annular channel 18 and is connected in series with the cold heat exchanger 15, part of which is also shown in FIG.
• the part of the regenerator 12 shown in FIG. 2 is further provided with a through opening 12a which can be closed by a plunger 19. In the closed position, the plunger 19 fills the through-opening 12a of the regenerator 12, which acts as a bypass, so that there is no dead space in the normal operation of the machine as a result of the bypass.
• the plunger 19 forming the bypass valve in connection with the through opening 12a can be moved out of its closed position shown in FIG. 2 against the force of a return spring 21 by an electromagnet 20.
• This release position and thus the opening of the bypass is shown in dashed lines in FIG. 2.
• the process gas essentially flows through the through-opening 12a, bypassing the regenerator 12, in order in this way to prevent the cold heat exchanger 15 and thus the air heat exchanger 16 (not shown in FIG. 2) from freezing.

Landscapes

• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Thermal Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Sorption Type Refrigeration Machines (AREA)
• Fluid-Pressure Circuits (AREA)
• Engine Equipment That Uses Special Cycles (AREA)
• Compressor (AREA)
• Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
• Devices That Are Associated With Refrigeration Equipment (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=7752259

Family Applications (1)

Country Status (8)

Families Citing this family (6)

Family Cites Families (6)

• 1995
  • 1995-01-25 DE DE19502190A patent/DE19502190C2/de not_active Expired - Fee Related
• 1996
  • 1996-01-13 US US08/860,211 patent/US6029449A/en not_active Expired - Fee Related
  • 1996-01-13 EP EP96900320A patent/EP0805941B1/fr not_active Expired - Lifetime
  • 1996-01-13 WO PCT/EP1996/000134 patent/WO1996023182A1/fr not_active Ceased
  • 1996-01-13 ES ES96900320T patent/ES2139327T3/es not_active Expired - Lifetime
  • 1996-01-13 KR KR1019970705172A patent/KR19980701775A/ko not_active Abandoned
  • 1996-01-13 JP JP8522582A patent/JPH11503511A/ja active Pending
  • 1996-01-13 AT AT96900320T patent/ATE186391T1/de not_active IP Right Cessation
  • 1996-01-13 DE DE59603564T patent/DE59603564D1/de not_active Expired - Fee Related

Non-Patent Citations (1)

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