Mitsubishi Denki Kabushiki Kaisha

Moriya Miyamoto

Osamu Morimoto

Tomohiko Kasai

Yoshihiro Sumida

Hidekazu Tani

Hitoshi Iijima

Fujio Hitomi

Takashi Ikeda

Hirofumi Koge

Hiroshi Nakata

Hiroaki Hama

Masami Imanishi

Mitsunori Kurachi

Hideaki Tagashira

Takeshi Yoshida

Keiji Nonami

Seiji Inoue

Toshihiro Kikukawa

Shohichiroh Masuda

A heat source unit and refrigerant used in an existing refrigeration system are replaced with new refrigerant and a new heat source unit which employs the new refrigerant and is equipped with an oil separator and extraneous-matter trapping device. An indoor unit of the existing refrigeration system may be used, in its present form, or replaced with a new indoor unit. Further, connecting pipes used for the existing refrigeration are reused. After replacement of refrigerant, the refrigeration system performs an ordinary operation after having performed a cleaning operation. The extraneous-matter trapping device is provided in a refrigerant pipe close to the heat source unit or in a bypass channel connected to the refrigerant pipe close to the heat source unit. Alternatively, only the heat source unit of the existing refrigeration system is replaced with a new one, and there is employed refrigeration oil which has no mutual solubility with respect to HFC or has very low mutual solubility.

Refrigeration system, and method of updating and operating the same

An apparatus for controlling a refrigeration cycle for circulating a refrigerant through a compressor a heat exchanger for condensation a flow rate control valve and a heat exchanger for evaporation connected each other, comprising: a first operation means for changing a heat exchanging capability of said heat exchanger for condensation a second operation means for changing a heat exchanging capability of said heat exchanger for evaporation a means for operating a running capacity for changing a running capacity of said compressor, and a control means for reducing a difference between a running condition on a high pressure side or a low pressure side of said refrigeration cycle and a target, wherein when a difference between a running condition on a high or low pressure side and its target is reduced, the control means bring the running condition closer to the target, minimizes a consumption energy, and bring a temperature difference of a heat exchanging fluid between an inlet and an outlet of the heat exchanger for condensation closer to a target temperature difference.

Apparatus for controlling refrigeration cycle and a method of controlling the same

A refrigerant circulation system of the present invention includes a compressor, a condenser, a evaporator, a throttle device and a control unit. The control unit controls a composition of a refrigerant circulating in the refrigerant circulation system based on a temperature and pressure of the refrigerant of an inlet and outlet portion of the compressor, condenser, evaporator and throttle device. The control unit controls to open and close the throttle device to change the composition of the refrigerant circulating in the refrigerant circulation system.

Refrigerant circulating system

A heat storage type air conditioning system capable of performing refrigerant receiving and discharging control and oil quantity control, which, in operating the general cooling circuit and the cold radiating circuit simultaneously or separately, is free from difficulties that the compressor is damaged or the cooling capacity is lowered when the quantities of refrigerant in those circuits are excessively increased or decreased, and is able to continue the operations with the quantity of refrigerant and the quantity of ice machine oil adjusted to suitable values. In the heat storage type air conditioning system, evaporators are provided in a general cooling circuit driven by a compressor and in a cold radiating circuit driven by a refrigerant gas pump, respectively, so that those circuits operate independently of each other. Furthermore, bypass circuits are provided to allow refrigerant to flow between liquid pipes and between gas pipes in those circuits. In a cold storing operation, the bypass circuits are closed, so that a cold storing circuit is formed by the compressor, a condenser, a first pressure reducing mechanism, and a cold storing heat exchanger.

Heat storage type air conditioning apparatus

Growing community of inventors

Wakayama, Japan

Moriya Miyamoto