Mitsubishi Denki Kabushiki Kaisha

Yasuo Nakashima

Hitoshi Iijima

Kiyoshi Sakuma

Fumio Matsuoka

Mitsuo Umehara

Takashi Watanabe

Yasuo Sato

Akio Fukushima

Yoshiaki Tanimura

Kisuke Yamazaki

Takao Komai

Toshihiko Enomoto

Hiroshi Kasagi

Junji Tamari

Tatsuya Mochizuki

Kazuo Ishino

Nobuyuki Miyazaki

Isamu Nakajima

A defrosting system for a heat exchanger includes a temperature detector arranged adjacent to the exchanger, a temperature memory for storing temperature data detected by the detector, and a central processing unit, wherein when a second temperature which is detected by the temperature detector after normal operation requested by a user has restarted and after a predetermined minimum defrosting prohibitive time has passed, drops by a predetermined difference in temperature from a first temperature which is detected by the temperature detector after the normal operation has restarted and after a predetermined defrosting prohibitive time has passed, and the second temperature is a predetermined temperature or below; the central processing unit carries out the defrosting operation. As a result, when the amount of frost has rapidly increased during the defrosting prohibitive time, the defrosting operation is carried out even if the defrosting prohibitive time has not passed, thereby deteriorating the capability of the exchanger and preventing the frost from remaining after the defrosting operation has been completed.

Defrosting system for a heat exchanger

A multiroom air conditioner has a plurality of indoor heat exchangers connected to a single outdoor heat exchanger. A reversible expansion valve is installed on a liquid-side branch pipe for each of the indoor heat exchangers, and a solenoid valve is installed on a gas-side branch pipe for each indoor heat exchanger. Temperature sensors are provided on the liquid-side branch pipes, on the gas-side branch pipes, and on the outlet side during cooling of the outdoor heat exchanger. A pressure sensor or a temperature sensor detects the saturation temperature on the high-pressure side of the compressor. Based on the saturation temperature on the high-pressure side of the compressor, the temperature on the outlet side during cooling of the outdoor heat exchanger, and the temperatures in the liquidside branch pipes, a controller controls the expansion valves so as to obtain a target degree of subcooling during cooling and heating. The controller can also control the expansion valves so that the temperatures in each of the branch pipes are approximately equal to one another.

Multiroom air conditioner

An improved air conditioner for supplying temperature-controlled air to the interior of a room from a ceiling position where the air conditioner is installed without danger of condensate dripping from the air conditioner into the room. Air is sucked from an outer case intake vent into a heat exchanger and the cooled air is blown into the room with blowers. The heat exchanger and the blowers are installed in a suspended outer case in a space above the ceiling of the room. The air sucked from the intake vent is led to air supply vents provided on both sides of the undersurface of the outer case through the air supply trunk, the air supply trunk being divided into sections by a bulkhead.

Ceiling suspended air conditioner

A control device for refrigeration cycle constructed with a compressor, a condenser, an electrically operated expansion valve, an evaporator, and so forth, all being connected in series, wherein there are further provided a by-pass extending from an inlet or an outlet or both of the expansion valve upto an inlet of the compressor through a capillary tube; a first temperature sensor to sense a temperature of a cooling medium at the inlet of the compressor; a second temperature sensor to sense a temperature of the cooling medium within an intake tubing, through which the cooling medium is taken into the inlet of the compressor; and a control device which calculates a super-heat quantity of the cooling medium taken into the compressor on the basis of a difference between the detection outputs of the first and second temperature sensors, and controls a degree of opening of the electrically operated expansion valve, thereby enabling the refrigeration cycle to be operated at high efficiency and in an energy-saving mode.

Control device for refrigeration cycle

Growing community of inventors

Shizuoka, Japan

Yasuo Nakashima