Patents by Inventor Ikuhiro Iwata

Ikuhiro Iwata has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 12650251
    Abstract: An air conditioner, which is a heat pump apparatus, includes a refrigerant circuit, a compressor, and a composition adjustment mechanism. The refrigerant circuit circulates a non-azeotropic mixture refrigerant including a first refrigerant and a second refrigerant having a boiling point higher than the first refrigerant. The compressor compresses the non-azeotropic mixture refrigerant. The first refrigerant is a compound represented by a molecular formula having one or more carbon-carbon unsaturated bonds. The composition adjustment mechanism is provided in the refrigerant circuit. The composition adjustment mechanism prevents an increase in the rate of the first refrigerant included in the non-azeotropic mixture refrigerant discharged from the compressor.
    Type: Grant
    Filed: September 28, 2023
    Date of Patent: June 9, 2026
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Ikuhiro Iwata, Eiji Kumakura, Tetsushi Tsuda, Shinjiro Domi, Atsushi Yoshimi
  • Publication number: 20260092730
    Abstract: A refrigeration cycle apparatus is caused to be in a normally operable state in accordance with the mixture ratio of difluoromethane occupying a refrigerant charged in the refrigeration cycle apparatus. A refrigeration cycle apparatus includes a refrigerant circuit including a compressor and performs a refrigeration cycle by circulating a refrigerant in the refrigerant circuit with the compressor. A heat-source-side controller judges the mixture ratio of difluoromethane occupying the refrigerant charged in the refrigerant circuit. The heat-source-side controller further performs control relating to the refrigeration cycle on the basis of the mixture ratio of difluoromethane judged by the judgement unit.
    Type: Application
    Filed: December 5, 2025
    Publication date: April 2, 2026
    Applicant: DAIKIN INDUSTRIES, LTD.
    Inventors: Takuro YAMADA, Atsushi YOSHIMI, Eiji KUMAKURA, Ikuhiro IWATA
  • Patent number: 12472800
    Abstract: A refrigeration cycle device for a vehicle includes a refrigerant circuit, in which a zeotropic refrigerant mixture is circulated, including a utilization heat exchanger including a first heat exchange portion and a second heat exchange portion disposed in series with the first heat exchange portion in a direction in which the zeotropic refrigerant mixture flows in the refrigerant circuit. The first heat exchange portion is disposed on an upstream side of the second heat exchange portion in a direction in which the zeotropic refrigerant mixture flows when the utilization heat exchanger functions as an evaporator of the zeotropic refrigerant mixture.
    Type: Grant
    Filed: September 28, 2023
    Date of Patent: November 18, 2025
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Ikuhiro Iwata, Eiji Kumakura, Tetsushi Tsuda, Shinjiro Domi
  • Patent number: 12442549
    Abstract: An air conditioner includes an ejector that raises a pressure of refrigerant by using energy for refrigerant decompression and expansion. A switching mechanism switches between a refrigerant flow in a first operation and a refrigerant flow in a second operation. The air conditioner is configured such that in the first operation, refrigerant compressed by a compression mechanism radiates heat in a use-side heat exchanger and is decompressed and expanded by the ejector while refrigerant evaporated in a heat-source-side heat exchanger is raised in pressure by the ejector. The air conditioner is configured such that in the second operation, refrigerant compressed by the compression mechanism radiates heat in the heat-source-side heat exchanger and is decompressed and expanded by a first expansion valve before being evaporated in the use-side heat exchanger while refrigerant does not flow through the ejector.
    Type: Grant
    Filed: March 29, 2022
    Date of Patent: October 14, 2025
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Atsushi Yoshimi, Takuro Yamada, Eiji Kumakura, Ikuhiro Iwata, Takeru Miyazaki
  • Patent number: 12422175
    Abstract: Refrigerant is caused to be in a superheating state without impairing the performance of a cascade heat exchanger. A refrigerant cycle system includes a first refrigerant circuit, a second refrigerant circuit, and a first cascade heat exchanger. The first cascade heat exchanger exchanges heat between a first refrigerant that flows in the first refrigerant circuit and a second refrigerant that flows in the second refrigerant circuit. The refrigerant cycle system includes a switching mechanism. The switching mechanism switches a flow path of a refrigerant of at least either one of the first refrigerant circuit and the second refrigerant circuit. The first cascade heat exchanger includes a first main heat exchanging unit acid a first sub heat exchanging unit. The first sub heat exchanging unit is configured to cause the first refrigerant that has passed through the first main heat exchanging unit to be in a superheating state.
    Type: Grant
    Filed: June 11, 2020
    Date of Patent: September 23, 2025
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Eiji Kumakura, Takuro Yamada, Atsushi Yoshimi, Ikuhiro Iwata, Tomoatsu Minamida
  • Patent number: 12405036
    Abstract: A heat transfer method uses a heat transfer system including: a heat source unit in which heat is exchanged between a heat transfer medium and a heat source; a utilization unit in which heat is exchanged between the heat transfer medium and a temperature adjustment target; and a first flow path and a second flow path that connect the heat source unit and the utilization unit. The heat transfer medium flows through the first flow path from the heat source unit to the utilization unit, and flows through the second flow path from the utilization unit to the heat source unit. In the heat transfer method, inorganic hydrate slurry, in which an inorganic hydrate that absorbs heat when dissolved in water is mixed with water, is used as the heat transfer medium.
    Type: Grant
    Filed: March 23, 2023
    Date of Patent: September 2, 2025
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Takeru Miyazaki, Teruo Kido, Takuro Yamada, Atsushi Yoshimi, Ikuhiro Iwata, Eiji Kumakura
  • Publication number: 20250224165
    Abstract: A refrigeration cycle apparatus includes a compressor, a utilization-side heat exchanger, a heat source-side expansion valve, a heat source-side heat exchanger, an accumulator, and a main refrigerant circuit. A non-azeotropic refrigerant mixture is sealed in the main refrigerant circuit. A first value obtained by dividing a value obtained by subtracting a second amount from a first amount by the first amount exceeds a value determined in accordance with a mixed refrigerant. The first amount is an amount of the mixed refrigerant sealed in the main refrigerant circuit. The second amount is an amount of a liquid refrigerant stored in the accumulator.
    Type: Application
    Filed: March 27, 2025
    Publication date: July 10, 2025
    Applicant: DAIKIN INDUSTRIES, LTD.
    Inventors: Ikuhiro IWATA, Eiji KUMAKURA
  • Patent number: 12320556
    Abstract: An air conditioner includes: a heat-source-side unit including a compressor and a heat-source-side heat exchanger; use-side units each including a use-side heat exchanger; an intermediate unit that causes the use-side heat exchanger of each of the use-side units to individually function as an evaporator or a radiator of a refrigerant; and two connection pipes that each connect the heat-source-side unit and the intermediate unit. The intermediate unit includes: an ejector that is configured to pressurize the refrigerant evaporated in the use-side heat exchanger that functions as the evaporator by using a driving flow; and a gas-liquid separator into which the refrigerant flowing out from the ejector flows.
    Type: Grant
    Filed: September 30, 2022
    Date of Patent: June 3, 2025
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Eiji Kumakura, Atsushi Yoshimi, Takuro Yamada, Ikuhiro Iwata, Takeru Miyazaki
  • Patent number: 12298046
    Abstract: An air conditioner includes: a heat-source-side unit including a compressor and a heat-source-side heat exchanger; use-side units each including a use-side heat exchanger; an intermediate unit that causes the use-side heat exchanger of each of the use-side units to individually function as an evaporator or a radiator of a refrigerant; and three or more connection pipes that connect the heat-source-side unit to the intermediate unit. The intermediate unit includes: an ejector that pressurizes the refrigerant; and a gas-liquid separator into which the refrigerant flowing out from the ejector flows. The refrigerant that has released heat in any of the use-side units that perform a heating operation is not pressurized by the ejector.
    Type: Grant
    Filed: September 30, 2022
    Date of Patent: May 13, 2025
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Atsushi Yoshimi, Takuro Yamada, Eiji Kumakura, Ikuhiro Iwata, Takeru Miyazaki
  • Publication number: 20250115796
    Abstract: A refrigeration cycle apparatus (1) is capable of performing a refrigeration cycle using a small-GWP refrigerant. The refrigeration cycle apparatus (1) includes a refrigerant circuit (10) and a refrigerant enclosed in the refrigerant circuit (10). The refrigerant circuit includes a compressor (21), a condenser (23), a decompressing section (24), and an evaporator (31). The refrigerant contains is a small-GWP refrigerant.
    Type: Application
    Filed: December 19, 2024
    Publication date: April 10, 2025
    Applicant: DAIKIN INDUSTRIES, LTD.
    Inventors: Eiji KUMAKURA, Takuro YAMADA, Atsushi YOSHIMI, Ikuhiro IWATA, Yoshinari ASANO, Keisuke OHTSUKA, Keiji AOTA, Mitsushi ITANO, Shun OHKUBO, Tatsuya TAKAKUWA, Daisuke KARUBE, Yuuki YOTSUMOTO, Kenji GOBOU, Hitomi KUROKI, Tomoyuki GOTOU, Akihito MIZUNO, Yasufu YAMADA, Tatsumi TSUCHIYA, Yuuichi YANAGI, Yoshikazu NAKAO, Takeo ABE, Yumi TODA, Tetsushi TSUDA
  • Patent number: 12253277
    Abstract: An air conditioner includes: use-side units that are each switchable between a cooling operation and a heating operation; and a heat-source-side unit including a compressor, a discharge pipe through which a refrigerant discharged from the compressor flows, a first main heat-source-side flow path and a second main heat-source-side flow path that branch off from the discharge pipe, a first heat-source-side heat exchanger, a second heat-source-side heat exchanger, a first economizer heat exchanger, and a second economizer heat exchanger. The first heat-source-side heat exchanger is connected to the first economizer heat exchanger in series in the first main heat-source-side flow path. The second heat-source-side heat exchanger is connected to the second economizer heat exchanger in series in the second main heat-source-side flow path.
    Type: Grant
    Filed: March 25, 2022
    Date of Patent: March 18, 2025
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Atsushi Yoshimi, Takuro Yamada, Eiji Kumakura, Ikuhiro Iwata, Takeru Miyazaki
  • Patent number: 12235027
    Abstract: Efficiency in refrigerant charging work is addressed when a refrigerant recovered from the first heat source unit is to be charged to a second heat source unit. In a refrigerant charging method in which a first heat source unit of an already installed refrigeration cycle apparatus in which a refrigeration cycle is to be performed by a refrigerant that circulates is replaced with a second heat source unit, transferring the refrigerant from the first heat source unit to the second heat source unit is included. In addition, the method includes measuring the weight of the refrigerant that is transferred from the first heat source unit to the second heat source unit.
    Type: Grant
    Filed: September 20, 2019
    Date of Patent: February 25, 2025
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Takuro Yamada, Atsushi Yoshimi, Eiji Kumakura, Ikuhiro Iwata
  • Publication number: 20250043787
    Abstract: The robustness of refrigerant against disproportionation reactions is improved. A method uses, as refrigerant for a compressor, a composition that contains one or two or more selected from a group of ethylene-based fluoroolefins, 2,3,3,3-tetrafluoropropene (HFO-1234yf), and 1,3,3,3-tetrafluoropropene (HFO-1234ze), in which the compressor includes a discharge pipe made of metal having a greater heat capacity than a discharge pipe of a compressor that uses R32, R410A, R134a, or R404A as refrigerant, or a casing that includes an intake pipe connection section made of metal having a greater heat capacity than an intake pipe connection section of a casing of the compressor that uses R32, R410A, R134a, or R404A as refrigerant.
    Type: Application
    Filed: October 25, 2024
    Publication date: February 6, 2025
    Applicant: DAIKIN INDUSTRIES, LTD.
    Inventors: Tomoyuki GOTO, Takashi USUI, Taichi OZAKI, Eiji KUMAKURA, Ikuhiro IWATA, Masaki TANAKA
  • Patent number: 12163706
    Abstract: A refrigeration apparatus includes: a compressor; an outdoor heat exchanger connected to the compressor; an indoor heat exchanger connected to the compressor; and an expansion valve disposed between the outdoor heat exchanger and the indoor heat exchanger. In cooling operation, a refrigerant flows through the compressor, the outdoor heat exchanger, the expansion valve, and the indoor heat exchanger in this order. In heating operation, the refrigerant flows through the compressor, the indoor heat exchanger, the expansion valve, and the outdoor heat exchanger in this order. The refrigerant is an HFO (hydrofluoroolefin) refrigerant or a refrigerant mixture that includes an HFO refrigerant. The indoor heat exchanger and the outdoor heat exchanger are cross-fin-type heat exchangers or stack-type heat exchangers.
    Type: Grant
    Filed: March 28, 2022
    Date of Patent: December 10, 2024
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Ikuhiro Iwata, Eiji Kumakura, Takuro Yamada, Ryuhei Kaji, Tomoki Hirokawa
  • Patent number: 12163712
    Abstract: A heat-source-side heat exchanger is divided so that a heat-source-side heat exchanger that functions as an evaporator also functions as an intermediate cooler. Since, when an air conditioner includes a bypass pipe, a heat-source-side heat exchanger that functions as an evaporator and as an intermediate cooler also further functions as a radiator, operation efficiency is increased.
    Type: Grant
    Filed: March 29, 2022
    Date of Patent: December 10, 2024
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Atsushi Yoshimi, Takuro Yamada, Eiji Kumakura, Ikuhiro Iwata, Takeru Miyazaki
  • Patent number: 12163707
    Abstract: In a refrigeration cycle apparatus, a switching mechanism includes a first channel and performs switching among a first, second and third connection states. In the first connection state, the refrigeration cycle apparatus repeatedly performs a first cycle in which refrigerant flows through a compressor, a first heat exchanger, a second heat exchanger, and the compressor in that order. In the second connection state, the refrigeration cycle apparatus repeatedly performs a second cycle in which refrigerant flows through the compressor, the second heat exchanger, the first heat exchanger, and the compressor in that order. In the third connection state, a passage between the compressor and the first heat exchanger and a passage between the compressor and the second heat exchanger are closed, and the first channel in the refrigeration cycle apparatus provides interconnection between the first heat exchanger and the second heat exchanger.
    Type: Grant
    Filed: March 29, 2022
    Date of Patent: December 10, 2024
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Takeru Miyazaki, Hiromune Matsuoka, Atsushi Yoshimi, Eiji Kumakura, Ikuhiro Iwata, Tomoatsu Minamida, Takuro Yamada
  • Patent number: 12140358
    Abstract: A refrigerant cycle system includes: a primary-side cycle of a vapor compression type that circulates a first refrigerant; a secondary-side cycle of a vapor compression type that circulates a second refrigerant; and a cascade heat exchanger that exchanges heat between the first refrigerant and the second refrigerant. The secondary-side cycle includes a secondary-side heat exchanger that uses cold or heat obtained by the second refrigerant from the cascade heat exchanger. The secondary-side heat exchanger includes a flat multi-hole pipe.
    Type: Grant
    Filed: June 10, 2020
    Date of Patent: November 12, 2024
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Takuro Yamada, Eiji Kumakura, Atsushi Yoshimi, Ikuhiro Iwata, Tomoatsu Minamida
  • Patent number: 12092374
    Abstract: A refrigerant cycle system includes: a first refrigerant circuit that includes a first heat exchanger, a first compressor, and a first cascade heat exchanger and that is configured as a first vapor compression refrigeration cycle; a second refrigerant circuit that includes the first cascade heat exchanger, a second compressor, and a second heat exchanger and that is configured as a second vapor compression refrigeration cycle; a first unit that accommodates the first heat exchanger and the first compressor; a second unit that accommodates the first cascade heat exchanger and the second compressor; and a third unit that accommodates the second heat exchanger. The first unit, the second unit, and the third unit are disposed apart from each other. The first cascade heat exchanger performs heat exchange between a first refrigerant that flows through the first refrigerant circuit and a second refrigerant that flows through the second refrigerant circuit.
    Type: Grant
    Filed: June 11, 2020
    Date of Patent: September 17, 2024
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Takuro Yamada, Atsushi Yoshimi, Eiji Kumakura, Ikuhiro Iwata, Kazuhiro Furusho, Mikio Kagawa, Michio Moriwaki, Tomoatsu Minamida, Hiromune Matsuoka, Junya Minami
  • Patent number: 12066222
    Abstract: At a refrigeration cycle device, an injection pipe and an economizer heat exchanger are provided at a main refrigerant circuit. In addition, the refrigeration cycle device includes a sub-refrigerant circuit having a sub-usage-side heat exchanger. At the refrigeration cycle device, the sub-usage-side heat exchanger functions as an evaporator of a sub-refrigerant and cools a main refrigerant that has been cooled at the economizer heat exchanger, or functions as a radiator of the sub-refrigerant and heats the main refrigerant that has been cooled at the economizer heat exchanger.
    Type: Grant
    Filed: September 30, 2019
    Date of Patent: August 20, 2024
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Eiji Kumakura, Ikuhiro Iwata, Kazuhiro Furusho, Ryusuke Fujiyoshi, Hiromune Matsuoka
  • Patent number: 12007150
    Abstract: Even if, in decompressing a refrigerant by an expansion mechanism, the temperature of the refrigerant cannot be sufficiently reduced, in order to increase the evaporation capacity of a use-side heat exchanger, a main expansion mechanism including an expansion element of a rotary or scroll type that causes power to be produced by decompressing a main refrigerant is provided at a main refrigerant circuit in which the main refrigerant circulates. Further, a sub-refrigerant circuit that differs from the main refrigerant circuit and in which a sub-refrigerant circulates is provided. A sub-use-side heat exchanger that is provided at the sub-refrigerant circuit and that functions as an evaporator of the sub-refrigerant is caused to function as a heat exchanger that cools the main refrigerant that flows between the main expansion mechanism and a main use-side heat exchanger.
    Type: Grant
    Filed: March 31, 2021
    Date of Patent: June 11, 2024
    Assignee: Daikin Industries, Ltd.
    Inventors: Ikuhiro Iwata, Eiji Kumakura, Kazuhiro Furusho, Ryusuke Fujiyoshi, Hiromune Matsuoka