Mitsubishi Denki Kabushiki Kaisha

Hajime Kitauchi

Fumio Matsuoka

Keiko Okuma

Ken Tomita

Jiro Okajima

Mutsumi Nakamura

Yasuo Shibuya

A cooling and heating concurrent operation type of multiple refrigeration cycle comprises an indoor unit including a variable delivery type of compressor and an outdoor heat exchanger; indoor units including indoor heat exchangers, respectively; triple connection pipes of a high pressure gas pipe, a high pressure liquid pipe and a low pressure gas pipe, the triple connection pipes connecting between the outdoor unit and the indoor units; pressure detection means for detecting the intake pressure of the compressor and the discharge pressure of the compressor; and calculation and control means for comparing two detected values of the intake pressure and the discharge pressure of the compressor with two set values of a set intake pressure and a set discharge pressure, and for making variable controls of the compression capability of the compressor and the heat exchange capability of the outdoor heat exchanger based on the respective deviation values between the respective detected values and the respective set values, which are obtained as the results of the comparison.

Cooling and heating concurrent operation type of multiple refrigeration

A decentralization type control apparatus for an air-conditioning or a refrigerating apparatus comprising a plurality of terminal control units and a central control unit for controlling the plurality of terminal control units. Each of the terminal control units is provided with a monitoring and controlling section for monitoring operations of the central control unit, a first memory part which stores information output from the central control unit through the monitoring and controlling section and information input into the terminal control unit itself, a second memory part storing a control program for a load, a control part for controlling the air conditioning or refrigerating apparatus by the information stored in the memory parts, and an output part generating an alarm to the outside, wherein when a fault in the central control unit is detected by the monitoring and controlling section, the terminal control unit solely takes over operations to control the air-conditioning or refrigerating apparatus and generates from the output part an alarm informing the fault of the central control unit.

Decentralization type control apparatus for an air-conditioning or a

The disclosed temperature control system for an air conditioner includes a sensor for sensing an actual air temperature and a comparator for determining the temperature difference between the sensed actual air temperature and a set air temperature after their conversion to digital voltages. The temperature difference is stored in a memory and is also applied to a calculator where a rate of change in temperature per unit time is calculated from the temperature difference thus formed and from that temperature which had occurred just before a predetermined time stored in the memory. A control unit responds to both the temperature difference and the rate of change in temperature per unit time to increase or decrease the number of compressors put into operation with respect to the number of the compressors operated at the just preceeding interval of time.

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Nagasaki, Japan

Hajime Kitauchi