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).

  • 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
  • Patent number: 11994323
    Abstract: There is provided a refrigerant charging method in which a foreign material and moisture are avoided from entering a heat source unit until a refrigeration cycle apparatus is configured. The refrigerant charging method is a method of charging a refrigerant to a refrigerant circuit in which a refrigeration cycle is to be performed by a circulating refrigerant, the refrigerant circuit being configured by connecting a second heat source unit and a utilization unit to each other. The refrigerant charging method includes charging a first refrigerant to the second heat source unit before connecting the second heat source unit to the utilization unit to configure the refrigerant circuit, and connecting the second heat source unit to the utilization unit and charging a second refrigerant that differs from the first refrigerant to the refrigerant circuit to obtain the circulating refrigerant that includes the second refrigerant and the first refrigerant that is charged in the second heat source unit.
    Type: Grant
    Filed: September 20, 2019
    Date of Patent: May 28, 2024
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Takuro Yamada, Atsushi Yoshimi, Eiji Kumakura, Ikuhiro Iwata, Shun Ohkubo
  • Patent number: 11988426
    Abstract: Efficiency in refrigerant charging work is addressed when a recovered refrigerant recovered from a first heat source unit is to be charged to a second heat source unit. A refrigerant charging method is a charging method used when 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 to be replaced with a second heat source unit. The refrigerant charging method includes recovering a first refrigerant from an already installed refrigeration cycle apparatus and obtaining a recovered refrigerant and charging the recovered refrigerant and charging a second refrigerant whose composition differs from the composition of the recovered refrigerant to the refrigeration cycle apparatus after renewal that includes the second heat source unit.
    Type: Grant
    Filed: September 20, 2019
    Date of Patent: May 21, 2024
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Takuro Yamada, Atsushi Yoshimi, Eiji Kumakura, Ikuhiro Iwata, Shun Ohkubo
  • Patent number: 11976851
    Abstract: A refrigeration cycle device that includes a main refrigerant circuit and a sub-refrigerant circuit cools or heats a main refrigerant that flows between a main heat-source-side heat exchanger and a main usage-side heat exchanger by causing a sub-usage-side heat exchanger to function as an evaporator or a radiator of a sub-refrigerant. A first main expansion mechanism and a second main expansion mechanism that decompress the main refrigerant are provided on an upstream side and a downstream side of the sub-usage-side heat exchanger of the main refrigerant circuit.
    Type: Grant
    Filed: September 30, 2019
    Date of Patent: May 7, 2024
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Ikuhiro Iwata, Eiji Kumakura, Kazuhiro Furusho, Ryusuke Fujiyoshi, Hiromune Matsuoka
  • Patent number: 11959667
    Abstract: A suction injection pipe and a subcooling heat exchanger are provided at a main refrigerant circuit in which a 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 controller performs control for switching between a cooling action of the subcooling heat-exchanger that cools the main refrigerant that is sent to a main use-side heat exchanger by using the suction injection pipe and the subcooling heat exchanger, and a cooling action of the sub-refrigerant-circuit that cools the main refrigerant that is sent to the main use-side heat exchanger by using the sub-refrigerant circuit.
    Type: Grant
    Filed: September 27, 2019
    Date of Patent: April 16, 2024
    Assignee: Daikin Industries, Ltd.
    Inventors: Ikuhiro Iwata, Eiji Kumakura, Kazuhiro Furusho, Ryusuke Fujiyoshi, Hiromune Matsuoka
  • Patent number: 11906207
    Abstract: A two-stage refrigeration apparatus (500) includes a first cycle (510) and a second cycle (520). The first cycle (510) includes a first compressor (511), a first condenser (512), a first expansion mechanism (513), and a first evaporator (514) that are arranged in such a manner as to be connected to the first cycle. A first refrigerant circulates through the first cycle. The second cycle (520) includes a second downstream-side condenser (523) and a second evaporator (527) that are arranged in such a manner as to be connected to the second cycle. A second refrigerant circulates through the second cycle. The first evaporator (514) and the second downstream-side condenser (523) constitute a cascade condenser (531). In the cascade condenser (531), heat is exchanged between the first refrigerant and the second refrigerant. At least one of the first refrigerant and the second refrigerant is a refrigerant mixture containing at least 1,2-difluoroethylene (HFO-1132(E)).
    Type: Grant
    Filed: June 26, 2020
    Date of Patent: February 20, 2024
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Eiji Kumakura, Takuro Yamada, Atsushi Yoshimi, Ikuhiro Iwata, Mitsushi Itano, Daisuke Karube, Yuuki Yotsumoto, Kazuhiro Takahashi, Tatsuya Takakuwa, Yuzo Komatsu, Shun Ohkubo
  • Publication number: 20240027104
    Abstract: A refrigeration cycle apparatus includes a first refrigerant circuit and a second refrigerant circuit so as to improve the efficiency of operations. A first refrigerant circuit using a first refrigerant having a pressure of 1.2 MPa or less at 30° C. and a second refrigerant circuit using a second refrigerant having a pressure of 1.5 MPa or more at 30° C. are provided, and a dual cycle operation in which the first refrigerant circuit and the second refrigerant circuit are simultaneously operated to exchange heat between the first refrigerant and the second refrigerant and a single cycle operation in which the first refrigerant circuit is operated without operating the second refrigerant circuit to perform a cooling operation or heating operation are enabled in a switchable manner.
    Type: Application
    Filed: September 28, 2023
    Publication date: January 25, 2024
    Applicant: DAIKIN INDUSTRIES, LTD.
    Inventors: Hiroki IKARASHI, Atsushi YOSHIMI, Takuro YAMADA, Eiji KUMAKURA, Ikuhiro IWATA, Ryuhei KAJI, Takeru MIYAZAKI, Hiroki UEDA, Masaki TANAKA, Masaki NAKAYAMA, Hideho SAKAGUCHI, Osamu TANAKA, Hirokazu FUJINO