Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

Tetsuo Sano

Yasuhiro Arai

Hideaki Motohashi

Kokichi Furuhama

Koichi Goto

Kazuo Saito

Tetsuji Yamashita

Takaki Iwanaga

Katuyoshi Kumazawa

Kazuo Suzuki

Toshihiko Saito

Masao Ozu

Kenji Umezu

Masaya Yamazaki

Megumi Komazaki

Kazuhiro Moriyama

Fusao Hirasawa

Susumu Orita

Hideto Kuyama

Tutomu Hatakubo

Shinichi Kameyama

There is disclosed a heat exchanger tube for conducting refigerant in a heat exchanger. The inner surface of the tube has a convex portion having a broad tip and a plurality of inner fins. The area of the tip of the convex portion is larger than that of the tip of the inner fins. The height of the convex portion can be set at more than that of the inner fin. A heat exchanger according to the invention has a plurality of plate fins, each having a hole therein. Heat exchanger tubes pass through the holes of the plate fins. A method of manufacturing a heat exchanger comprises the steps of stacking a plurality of plate fins, each having a hole, with a predetermined space therebetween. Heat exchanger tubes are inserted through the holes. Then, the tubes are expanded to engage the plate fins. A refrigerating circuit utilizing a heat exchanger is also described.

Heat exchanger tube and method for manufacturing a heat exchanger

An air-conditioning apparatus forms a refrigerating cycle with a refrigerant heater and a compressor having two cylinders. The apparatus simultaneously carries out a refrigerant heating operation and a heat pump operation when a required heating capacity is high, and when the required heating capacity is low, only the heat pump operation. This operation technique helps reduce the size of the apparatus and expand a variable width of heating capacity. The apparatus also has a defrosting unit for defrosting an outdoor heat exchanger during the heat pump operation.

Air-conditioning apparatus

A refrigerating apparatus employs a mixture of coolants and a coolant controller for controlling a ratio between the coolants to adjust refrigerating capacity during a refrigerating operation. The apparatus has a compressor whose revolution speed is controlled to provide required refrigerating capacity. When the revolution speed of the compressor decreases below a lower set value or rises above an upper set value, the coolant controller controls the ratio between the coolants.

Refrigerating apparatus

An air conditioning system in which each alternative refrigerant can be fully utilized so as to present as much as actual COP in comparison with the conventional HCFC22 and to achieve safe use as operating refrigerants. The air conditioning system includes: a first refrigerant circuit in which a first refrigerant circulates, the first refrigerant circuit including: an indoor heat exchanger; and a fluid drive unit, connected to the indoor heat exchanger by way of a first piping, which drives the first refrigerant; a second refrigerant circuit in which a second refrigerant circulates, the second refrigerant circuit including: a compressor which comparesses the second refrigerant; an expansion valve, connected to the compression means, for expanding the second refrigerant; and an outdoor heat exchanger connected to the compressor and the expansion valve by way of a second piping; and an intermediate heat exchanger for heat-exchanging between the first refrigerant in the first refrigerant circuit and the second refrigerant in the second refrigerant circuit.

Air conditioning system with built-in intermediate heat exchanger with

An air conditioner employs a non-azeotropic refrigerant mixture without deteriorating the heat-exchange efficiency and air-conditioning capability of an indoor heat exchanger of the air conditioner. The indoor heat exchanger (3) has a fin on which a first path (33), a second path (34), and a third path (35) for passing the refrigerant mixture are arranged. The first path passes the refrigerant mixture from the leeward side toward the windward side of an air flow produced by an indoor fan (7), to form a counterflow of the refrigerant mixture against the air flow. The second path passes the refrigerant mixture from the windward side toward the leeward side of the air flow. Although the second path forms a parallel flow of the refrigerant mixture with respect to the air flow, it achieves moderate heat-exchange efficiency because the number of rows of piping on the leeward side is greater than that on the windward side and because the rows of piping do not overlap one another with respect to the air flow. The third path passes the refrigerant mixture from the windward side toward the leeward side and again from the windward side toward the leeward side of the air flow, to partly realize a counterflow of the refrigerant mixture against the air flow, to thereby improve the heat-exchange efficiency.

Air conditioner

In an air conditioner having at least an indoor unit 9 and an outdoor unit 11 through which a coolant flows, a saturation temperature of the coolant at 50.degree. C. is not less than 2500 kPa, and the indoor heat exchanger in the indoor unit satisfies a relationship of Hi.times.Li/(Di.sup.3 .times.Ni.sup.2).gtoreq.150 and the outdoor heat exchanger in the outdoor unit satisfies a relationship of Ho.times.Lo/(Do.sup.3 .times.No.sup.2).gtoreq. 60.

An air conditioner employs a refrigerating cycle in which a non-azeotropic mixture of high and low boiling coolants is sealed. The ratio between the high and low boiling coolants of the coolant mixture changes according to a change in the opening of an electric expansion valve 7. A level sensor 19 is arranged in an accumulator 17 that accumulates the liquid phase of the coolant mixture. A value detected by the level sensor is used to calculate the ratio between the high and low boiling coolants actually circulating in the refrigerating cycle. According to the opening of the valve 7 or the ratio between the actual quantities of the high and low boiling coolants, basic operation parameters such as the operation frequency of a compressor 1 are changed. This results in stabilizing and optimizing the operation of the refrigerating cycle even if a cycle temperature or pressure is changed due to a change in the ratio between the high and low boiling coolants of the coolant mixture.

A controller for controlling an air conditioner comprises a room temperature sensor for measuring a room temperature, a room temperature change computation circuit for computing a difference between the room temperature and a set temperature, an outdoor temperature sensor for measuring an outdoor temperature, a neural network for computing load on the air conditioner according to the temperature change, outdoor temperature, and room temperature, and a controller for controlling, according to the computed load, the operation frequency of a coolant compressor by controlling a compressor motor through a variable frequency circuit, thereby speedily bringing the room temperature to the set temperature and stably maintaining the room temperature at the set temperature. The neural network learns various operation characteristics of a refrigerating cycle of the air conditioner, and according to a result of the learning, controls the air conditioner.

Air conditioner controller

An air conditioning system in accordance with the present invention is disclosed which has a radiation plate including a radiation surface facing a room area. A column of air that is either cooled or heated by a heat exchanger in an indoor unit of the present air conditioning system, is directed to flow along the radiation surface of the radiation plate. The room area is then either cooled or heated by radiant energy using the radiation properties of the radiation surface.

Air conditioning system

An outdoor unit comprises a combustion unit for presenting combustion heat, a heating medium heating part for heating the heating medium with the combustion heat to vary in phase from liquid to gas, and a heating medium transferring part. A plurality of indoor units each have an indoor heat exchanger and a required heating capacity detecting part for detecting a required heating capacity in a region to be heated required for the indoor heat exchanger. The detecting part comprises a room temperature setting part, a room temperature detector, and a required heating capacity data output part for delivering required heating capacity data in the region to be heated depending on the difference between the preset room temperature and the detected room temperature. The distributing part couples the plural indoor units parallel to the outdoor unit so as to form individual enclosed heating medium circulation cycles. The controller controls the combustion quantity of the combustion unit and the heating medium transferring capacity according to the sum of the required heating capacity data, and controls the heating medium distribution amount of the distributing part for distributing the heating medium into each indoor heat exchanger depending on the ratio of the required heating capacity data.

Multi-type air heating apparatus utilizing phase variation of heating

A temperature setting unit is operated to set a desired temperature. An indoor temperature detector detects an indoor temperature. A timer is operated to set an operation start time. An indoor unit includes at least an indoor heat exchanger, an air duct associated with the indoor heat exchanger, a heat radiation member located in the air duct, a heat accumulator thermally coupled to the heat radiation member, and an electric heater for selectively supplying heat to the heat accumulator. An outdoor unit includes at least a compressor for cooperating with the indoor heat exchanger to constitute a heat pump refrigeration cycle for heating operation, and an outdoor exchanger. A controller outputs a first control signal for preheating the electric heater a predetermined period of time before operation start time by counting preset data of the operation start time from the timer, and a second control signal for setting the heat pump refrigeration cycle in a drive state at the operation start time. The controller controls the drive state on the basis of desired temperature data set by the temperature setting unit and indoor temperature data detected by the indoor temperature detector, thereby maintaining an indoor temperature at the desired temperature.

Heat pump with electrically heated heat accumulator

An air conditioner includes a compressor, four-way valve, outdoor side heat exchanger, expansion valve and indoor side heating exchanger, which components are sequentially connected via coolant tubes, thereby constructing a refrigeration cycle circuit which is capable of performing cooling (defrosting) and heating operations. A switching control valve is connected between the suction side of the compressor and the four-way valve. The control valve is opened when abnormal high pressure is produced in the refrigeration cycle and when the defrosting operation is performed. A first branch passage is connected at its one end between the four-way valve and indoor side heat exchanger, and at the other end to the control valve. During the heating operation, when the control valve is opened, the first branch passage forms a releasing circuit, thereby releasing the abnormal high pressure to the low pressure side of the refrigeration cycle. A second branch passage is connected at its one end between the outdoor side heat exchanger and the expansion valve and at the other end to the control valve. During the defrosting operation, the second branch passage forms a short-circuit which sequentially passes the compressor, four-way valve, outdoor side heat exchanger and control valve.

Growing community of inventors

Shizuoka-ken, Japan

Tetsuo Sano