Patents by Inventor Minoru Yoshikawa

Minoru Yoshikawa 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: 11903174
    Abstract: A system (20) for controlling an air conditioner (12) includes a plurality of pressure sensors (19) and a controller (13). Each of the pressure sensors (19) is positioned at an air inlet (15) of each of the racks (11). The controller (13) is configured to receive pressure values from the pressure sensors (19) and control an airflow rate of the cooling air supplied from the air conditioner (12) based on the pressure values. The controller (13) is configured to set a target pressure value for each pressure sensor (19) (S300), acquire a current pressure value for each pressure sensor (S401), calculate a pressure drop value for each pressure sensor (19) between the current pressure value and the target pressure value (S402), and adjust the airflow rate based on a maximum value among the plurality of the pressure drop values (S403 to S410).
    Type: Grant
    Filed: March 18, 2019
    Date of Patent: February 13, 2024
    Assignee: NEC CORPORATION
    Inventors: Nirmal Singh Rajput, Yoshinori Miyamoto, Hisato Sakuma, Minoru Yoshikawa
  • Patent number: 11825630
    Abstract: A cooling system includes: a local cooler that is positioned near a heat source and evaporates a liquid-phase refrigerant by receiving heat from the heat source; a turbo compressor that compresses a gas-phase refrigerant that absorbed the heat in the local cooler; an outdoor unit that condenses the gas-phase refrigerant supplied from the turbo compressor by heat dissipation; and an expansion valve that depressurizes the refrigerant supplied from the outdoor unit and sends the refrigerant to the local cooler. The refrigerant is a low-pressure refrigerant having a condensing pressure lower than a predetermined value.
    Type: Grant
    Filed: July 9, 2019
    Date of Patent: November 21, 2023
    Assignee: NEC CORPORATION
    Inventors: Takafumi Natsumeda, Minoru Yoshikawa, Masaki Chiba
  • Patent number: 11821667
    Abstract: A cooling apparatus includes a heat receiver that evaporates a low pressure heat transfer medium. The apparatus includes a compressor that compresses the evaporated heat transfer medium in a gas phase state, and a condenser that condenses the compressed heat transfer medium. The apparatus includes a receiver tank that receives and stores at least one of the heat transfer medium from any place in a flow path of the medium in the gas phase state that returns the medium to the heat receiver and the condensed medium in a liquid phase state. The apparatus includes an air storage tank that air separated from the heat transfer medium. The apparatus includes a liquid level controller that controls a liquid level in the receiver tank such that the heat transfer medium is stored in the receiver tank at a predetermined liquid level height.
    Type: Grant
    Filed: November 8, 2021
    Date of Patent: November 21, 2023
    Assignee: NEC CORPORATION
    Inventors: Yoshinori Miyamoto, Minoru Yoshikawa, Masaki Chiba
  • Patent number: 11774115
    Abstract: An air conditioner includes: a turbo compressor that compresses a heat medium; a heat exchanger that exchanges heat of the heat medium supplied from the turbo compressor with an atmosphere; and a supply flow path and a discharge flow path that connect the turbo compressor and the heat exchanger. At least one of the supply flow path and the discharge flow path includes piping, and the piping includes a gas barrier layer that covers a surface of a synthetic resin.
    Type: Grant
    Filed: August 12, 2021
    Date of Patent: October 3, 2023
    Assignee: NEC CORPORATION
    Inventors: Masaki Chiba, Kunihiko Ishihara, Minoru Yoshikawa, Junichi Miyamoto, Yoshinori Miyamoto
  • Publication number: 20230309273
    Abstract: The present disclosure can provide a system, method and non-transitory computer readable storage medium capable of generating a uniform airflow at a heat exchanger surface. A system includes: a cooling unit body (11, 21) having an airflow inlet (18, 28) and an airflow outlet (15, 25); a heat exchanger (12, 22) provided inside the cooling unit body; and a plurality of fans (16, 17, 26, 27) provided at the airflow inlet. The system may include air velocity sensors (265, 275) provided at the heat exchanger (22).
    Type: Application
    Filed: August 13, 2020
    Publication date: September 28, 2023
    Applicant: NEC Corporation
    Inventors: Nirmal Singh RAJPUT, Masaki Chiba, Yoshinori Miyamoto, Junichi Miyamoto, Minoru Yoshikawa
  • Publication number: 20230221084
    Abstract: A heat exchanger has a structure in which a heat exchanger main body through which coolant flows is obliquely installed in a box-shaped enclosure, the heat exchanger main body is constituted by a header pipe and a plurality of heat transfer pipes connected to the header pipe and disposed at predetermined intervals along a surface of a part of the header pipe, the header pipe has an area adjacent to an inner surface of the enclosure, and a seal section is provided between the inner surface of the enclosure and the area of the header pipe adjacent to the enclosure.
    Type: Application
    Filed: March 2, 2023
    Publication date: July 13, 2023
    Applicant: NEC Corporation
    Inventors: Koichi TODOROKI, Minoru YOSHIKAWA, Masaki CHIBA
  • Publication number: 20230213253
    Abstract: A cooling device using a refrigeration cycle in which a refrigerant is circulated through a heat receiver, a compressor, a heat radiator, and an expansion valve includes: a gas-liquid separator configured to perform gas-liquid separation on the refrigerant supplied from the expansion valve; a pump configured to send a liquid phase refrigerant separated by the gas-liquid separator to the heat receiver; and a control unit configured to control opening and closing of a refrigerant flow path of the refrigeration cycle, and an operation and stop of the compressor and the pump, wherein the control unit starts the operation of the pump on condition that a net positive suction head of the pump has reached a predetermined value or more.
    Type: Application
    Filed: September 13, 2021
    Publication date: July 6, 2023
    Applicant: NEC Corporation
    Inventors: Takashi OHTSUKA, Koichi Todoroki, Yoshinori Miyamoto, Masaki Chiba, Mahiro Hachiya, Minoru Yoshikawa
  • Patent number: 11683912
    Abstract: A cooling device includes: a duct that guides air that has absorbed heat generated inside a cooling target and has been discharged, to the cooling target; a cooler that is provided in the duct and cools the air flowing inside the duct; and an adjusting mechanism that is located on a downstream side of the cooler, adjusts an amount of the air discharged from the duct into a room where the cooling target is installed.
    Type: Grant
    Filed: August 10, 2021
    Date of Patent: June 20, 2023
    Assignee: NEC CORPORATION
    Inventors: Kenji Kobayashi, Koichi Todoroki, Nirmal Singh Rajput, Yoshinori Miyamoto, Masaki Chiba, Minoru Yoshikawa
  • Patent number: 11644249
    Abstract: This electronic apparatus 100 comprises a heating element 20, and a case 30. The case 30 has an opening hole 31. In order that a refrigerant COO will be sealed between the case 30 and the heating element 20, the outer periphery part of a first heating element external surface 21, which is the external surface of the heating element 20, is attached to the outer periphery part of the opening hole 31. Also, the refrigerant COO is a refrigerant that is capable of phase change from a liquid refrigerant LP-COO to a gas phase refrigerant GP-COO. As a result, it is possible to more efficiently cool the heat of the heating element 20.
    Type: Grant
    Filed: March 29, 2019
    Date of Patent: May 9, 2023
    Assignee: NEC CORPORATION
    Inventors: Mahiro Hachiya, Minoru Yoshikawa
  • Patent number: 11614288
    Abstract: A heat exchanger has a structure in which a heat exchanger main body through which coolant flows is obliquely installed in a box-shaped enclosure, the heat exchanger main body is constituted by a header pipe and a plurality of heat transfer pipes connected to the header pipe and disposed at predetermined intervals along a surface of a part of the header pipe, the header pipe has an area adjacent to an inner surface of the enclosure, and a seal section is provided between the inner surface of the enclosure and the area of the header pipe adjacent to the enclosure.
    Type: Grant
    Filed: July 8, 2020
    Date of Patent: March 28, 2023
    Assignee: NEC CORPORATION
    Inventors: Koichi Todoroki, Minoru Yoshikawa, Masaki Chiba
  • Patent number: 11609035
    Abstract: In a phase-change cooling apparatus including an indoor unit and an outdoor unit, a configuration to prevent dew condensation in the indoor unit causes the cooling performance to decrease; therefore, a refrigerant circulating apparatus according to an exemplary aspect of the present invention includes refrigerant-liquid thermal equilibrium means for mixing a first refrigerant liquid with a second refrigerant liquid and sending a reflux refrigerant liquid composed of the first refrigerant liquid and the second refrigerant liquid, the first refrigerant liquid being a liquid-phase refrigerant included in a gas-liquid two-phase refrigerant flowing in from heat receiving means, the second refrigerant liquid arising due to the gas-liquid two-phase refrigerant cooled by heat radiating means; a refrigerant passage configured for the gas-liquid two-phase refrigerant and the reflux refrigerant liquid to circulate between the heat receiving means and the refrigerant-liquid thermal equilibrium means; refrigerant-liquid r
    Type: Grant
    Filed: December 16, 2016
    Date of Patent: March 21, 2023
    Assignee: NEC CORPORATION
    Inventors: Minoru Yoshikawa, Hisato Sakuma, Masaki Chiba
  • Publication number: 20230023287
    Abstract: A cooling system (100) has a housing (101), a heat exchanger (110) and an air distribution controller (120). The housing (101) including an inlet (102) for receiving air exhausted from the server module and an outlet (103) for providing air to the server module. The heat exchanger (110) is mounted between the inlet (102) and the outlet (103), the heat exchanger (110) is configured that a refrigerant (111) contained in the heat exchanger (110) exchanges heat with air passing through the heat exchanger (110). The heat exchanger (110) accepts variation of the refrigerant liquid level. The air distribution controller (120) is mounted in an inlet side of the heat exchanger (110). The air distribution controller (120) has a movable plate which allows an airflow profile from the inlet to the heat exchanger (110) redirected. The air distribution controller (120) controls the airflow profile depending on the liquid level.
    Type: Application
    Filed: January 16, 2020
    Publication date: January 26, 2023
    Applicant: NEC Corporation
    Inventors: Nilmal Singh RAJPUT, Koichi TODOROKI, Takafumi NATSUMEDA, Mahiro HACHIYA, Minoru YOSHIKAWA
  • Publication number: 20220377944
    Abstract: The present invention provides an attachment for a server rack cooling system having at least one heat exchange condenser, the attachment includes: a pipe extension configured to connect to a portion of the server rack cooling system at which air and refrigerant are able to be transferred into the attachment from the at least one heat exchange condenser; a valve on the pipe extension configured to allow exhaust to the outside through the pipe extension at an open position and to block exhaust to the outside at a closed position; and an sensor disposed at a position inside of the pipe extension between the at least one heat exchange condenser and the valve and configured to provide a detection signal determined by a presence of fluid at the position of the sensor; wherein, the valve is opened and closed based on the detection signal from the sensor.
    Type: Application
    Filed: October 2, 2019
    Publication date: November 24, 2022
    Applicant: NEC Corporation
    Inventors: Nirmal Singh RAJPUT, Masaki CHIBA, Mahiro HACHIYA, Takafumi NATSUMEDA, Yoshinori MIYAMOTO, Minoru YOSHIKAWA
  • Publication number: 20220341669
    Abstract: A heat-radiation apparatus includes a housing and a plurality of heat-radiation modules which are aligned in a vertically-slanted manner with a predetermined inclination angle to a vertical line in the housing. A plurality of heat-radiation modules includes a plurality of heat exchangers which is aligned together in parallel and equipped with a plurality of fans to parallelize axial lines thereof with each other. In a manufacturing method of the heat-radiation apparatus, the number of heat-radiation modules is adjusted according to a radiation amount which is determined in advance.
    Type: Application
    Filed: April 21, 2022
    Publication date: October 27, 2022
    Applicant: NEC Corporation
    Inventors: Mahiro HACHIYA, Minoru YOSHIKAWA, Masaki CHIBA
  • Publication number: 20220279682
    Abstract: A cooling system includes: a local cooler that is positioned near a heat source and evaporates a liquid-phase refrigerant by receiving heat from the heat source; a turbo compressor that compresses a gas-phase refrigerant that absorbed the heat in the local cooler; an outdoor unit that condenses the gas-phase refrigerant supplied from the turbo compressor by heat dissipation; and an expansion valve that depressurizes the refrigerant supplied from the outdoor unit and sends the refrigerant to the local cooler. The refrigerant is a low-pressure refrigerant having a condensing pressure lower than a predetermined value.
    Type: Application
    Filed: July 9, 2019
    Publication date: September 1, 2022
    Applicant: NEC Corporation
    Inventors: Takafumi NATSUMEDA, Minoru YOSHIKAWA, Masaki CHIBA
  • Publication number: 20220279684
    Abstract: A cooling system includes: a local cooler that is positioned near a server serving as a heat source and that evaporates a refrigerant by directly receiving heat from the server to generate a gas-phase refrigerant; a compressor that compresses the gas-phase refrigerant; an outdoor unit that condenses the gas-phase refrigerant supplied from the compressor by dissipating heat from the gas-phase refrigerant; an expansion valve that depressurizes the refrigerant supplied from the outdoor unit and sends the refrigerant to the local cooler; a pair of detectors that are respectively provided at an inlet side and an outlet side of the compressor and detect a state of the gas-phase refrigerant supplied from the local cooler; and a proportional control valve and a high-speed on-off valve that are operated based on a refrigerant state ratio calculated from a detection value of the detectors.
    Type: Application
    Filed: July 9, 2019
    Publication date: September 1, 2022
    Applicant: NEC Corporation
    Inventors: Yoshinori MIYAMOTO, Takafumi NATSUMEDA, Minoru YOSHIKAWA
  • Patent number: 11428442
    Abstract: A cooling device includes a first evaporation unit, a second evaporation unit, a first condensation unit, a second condensation unit, common piping, a compressor, an expansion valve, a first valve, and a second valve. The common piping combines liquid-phase refrigerant flowing from the first condensation unit and liquid-phase refrigerant flowing from the second condensation unit. The first valve adjusts the liquid-phase refrigerant amount flowing into the first evaporation unit. The second valve adjusts the liquid-phase refrigerant amount flowing into the second evaporation unit. In addition, the pressure inside the common pipe is greater than the respective pressures inside the first evaporation unit and the second evaporation unit.
    Type: Grant
    Filed: March 19, 2019
    Date of Patent: August 30, 2022
    Assignee: NEC CORPORATION
    Inventors: Hisato Sakuma, Koichi Todoroki, Masaki Chiba, Takafumi Natsumeda, Minoru Yoshikawa
  • Publication number: 20220192057
    Abstract: A local cooler includes: a housing formed into a box shape; a heat exchanger provided along a slope extending upward to a rear portion from a lower position located on the front side of the housing; a first intake/exhaust port provided on a front surface of the housing; a second intake/exhaust port provided on a bottom surface of the housing; third intake/exhaust ports provided at a plurality of locations among side surfaces, upper surface and rear surface of the housing; and a closing plate capable of selectively shielding these intake/exhaust ports.
    Type: Application
    Filed: April 13, 2020
    Publication date: June 16, 2022
    Applicant: NEC Corporation
    Inventors: Koichi TODOROKI, Minoru YOSHIKAWA, Kunihiko ISHIHARA, Masaki CHIBA, Yoshinori MIYAMOTO, Takafumi NATSUMEDA, Nirmal Singh RAJPUT
  • Patent number: 11363744
    Abstract: When an enclosed space is formed, by at least one of surfaces forming an exterior shape of a shielding member and an intake or exhaust surface among surfaces forming an exterior shape of heat-generating housings, in such a way that a taken-in airflow and an exhausted airflow of the heat-generating housings installed in at least two rows can be separated or substantially separated, a cooling system includes: a duct formed to be able to separate or substantially separate a first airflow and a second airflow being intake/exhaust of a specific heat-generating housing among the heat-generating housings, and heat-generating housings other than the specific heat-generating housing, respectively; and a cooling enhancement unit enhancing cooling for the specific heat-generating housing by acting on the first airflow, thereby avoiding occurrence of a hot spot due to a high-heat-generating housing, in a system building an air-conditioning environment such as aisle capping.
    Type: Grant
    Filed: September 6, 2017
    Date of Patent: June 14, 2022
    Assignee: NEC CORPORATION
    Inventors: Minoru Yoshikawa, Hisato Sakuma, Yoshinori Miyamoto, Masaki Chiba
  • Patent number: 11343946
    Abstract: A cooling system including a vaporizer configured to absorb heat due to a liquid-phase refrigerant being vaporized, a condenser configured to discharge heat due to a refrigerant in a gaseous phase state being liquefied, a resistance body provided in a middle of a pipe passage ranging from the vaporizer to the condenser and applying a resistance to the refrigerant, state detection sensors provided in the pipe passage on an upstream and downstream sides of the resistance body and detecting a state of the refrigerant flowing through each side inside the pipe passage, and a flow rate controller configured to detect droplets in the refrigerant flowing through the pipe passage on the basis of a difference between detection values of the state detection sensors which are detected on the upstream and downstream sides of the resistance body, and controls a flow rate of the refrigerant on the basis of detection results.
    Type: Grant
    Filed: March 30, 2017
    Date of Patent: May 24, 2022
    Assignee: NEC CORPORATION
    Inventors: Arihiro Matsunaga, Koichi Todoroki, Hisato Sakuma, Minoru Yoshikawa