Daikin Industries, Ltd.

Masakazu Okamoto

Tetsuya Okamoto

Eiji Kumakura

Katsumi Sakitani

Michio Moriwaki

Hiroshi Yoh

Yasuhiro Kouno

Yume Inokuchi

Atsushi Okamoto

Atsushi Yoshimi

Ikuhiro Iwata

Shuji Fujimoto

Toshiyuki Kurihara

Masanori Ukibune

Yoshinari Sasaki

Qi Fang

Yurika Gotou

Takahiro Ozaki

A hot water supply apparatus includes a hot water supply channel. The hot water supply channel includes a heating section configured to heat water and a tank configured to store the water heated by the heating section. The hot water supply channel is configured to execute a first hot water supply operation in a hot water storage state in which a low-temperature layer, a medium-temperature layer, and a high-temperature layer are formed in the tank. The first hot water supply operation includes heating water in the medium-temperature layer to a first temperature by the heating section and supplying the water heated to a hot water supply target.

Hot water supply apparatus

A compressor includes a casing, compression mechanism disposed inside the casing, a discharge tube, a first temperature sensor, and a second temperature sensor. The compression mechanism compresses a sucked refrigerant, and discharges the compressed refrigerant to a refrigerant channel formed in an inner space of the casing. The compressed refrigerant flows from the inner space of the casing to an outside through the discharge tube. The first temperature sensor includes a temperature sensing portion disposed in the refrigerant channel, and directly measuring a temperature of the refrigerant. The second temperature sensor is disposed at a different position from the first temperature sensor. The second temperature sensor measures a temperature of one of a surface of the discharge tube, an inner space of the discharge tube, and a surface of the casing.

Compressor and refrigeration cycle device apparatus

An air conditioning system includes a heat pump unit including a radiator usable with a refrigerant, a gas furnace unit including a heating section arranged to heat passing air, a blower arranged to generate an air flow that passes through the radiator and the heating section, a first temperature sensor provided in a room, and a controller configured to control each action of the heat pump unit, the gas furnace unit, and the blower. The temperature sensor detects an indoor temperature in the room. The controller causes the gas furnace unit to operate as a heat source unit when a difference value obtained by subtracting the indoor temperature from a set temperature is equal to or greater than a first threshold at startup, and causes the heat pump unit to operate as a heat source unit when the difference value is less than the first threshold at startup.

Air conditioning system

An air conditioning system includes a heat pump having a refrigerant radiator, a gas furnace unit having a heating section to heat passing air, a blower generating air flow through the radiator and the heating section, and a controller controlling operation of the heat pump unit, the gas furnace unit, and the blower. The controller has a first operating mode in which the gas furnace unit operates alone as a heat source unit, a second operating mode in which the heat pump unit operates alone as a heat source unit, and a third operating mode in which the gas furnace unit and the heat pump unit operate at the same time as a heat source unit. The controller is configured to select the operating modes based on a parameter relating to outside air temperature that is the temperature of outside air.

An air conditioning system includes a heat pump unit including a radiator usable with a refrigerant, a gas furnace unit including a heating section arranged to heat passing air, a blower arranged to generate an air flow that passes through the radiator and the heating section, and a controller configured to control each action of the heat pump unit, the gas furnace unit, and the blower. The controller operates either the heat pump unit or the gas furnace unit as a heat source unit, generates a capacity command used to variably adjust operating capacity of the heat source unit, and executes switch control in order to switch the heat source unit from either one of the heat pump unit or the gas furnace unit to the other when an operating capacity level designated in the capacity command is within a predetermined numerical range for a predetermined time.

A refrigeration system includes a refrigerant circuit including a compressor and an expander which expands a refrigerant and generates power, for performing a refrigeration cycle. The refrigeration system includes a compressor control section and an expander control section which, when an operation stop signal is output during operation, reduces a rotational speed of the compressor and increases a rotational speed of the expander to increase the ratio of the rotational speed of the expander to the rotational speed of the compressor.

Refrigeration system

A refrigeration system includes a refrigerant circuit performing a vapor compression supercritical refrigeration cycle. The system includes a compression mechanism, a heat source heat exchanger, an expander, and a utilization heat exchanger. The expander includes, for two-stage compression, a high pressure side and a low pressure side throttle mechanism, both variable in the amount of throttling. A controller is configured to derive a target value, providing a maximum COP, for the pressure of high pressure refrigerant in the refrigerant circuit based on the temperature of refrigerant at the outlet of either the heat source side heat exchanger or the utilization side heat exchanger, whichever becomes a heat dissipation side heat exchanger functioning as a heat dissipation unit and on the temperature of a medium exchanging heat with refrigerant in the heat dissipation side heat exchanger, at the inlet of the heat dissipation side heat exchanger.

Control of supercritical refrigeration system

An on-off valve () is provided in an oil feed path (). When liquid refrigerant enters the oil feed pipe () from the oil separator (), the temperature of the liquid refrigerant whose pressure has been reduced in the on-off valve () dramatically decreases. When the amount of such a decrease in temperature detected by a temperature sensor () exceeds a specified amount, it is determined that the liquid refrigerant enters the oil feed pipe (), and the on-off valve () is closed.

Refrigerating apparatus

A compressor and an expander are provided in a refrigerant circuit of an air conditioner. In the compressor, refrigerator oil is supplied from an oil reservoir to a compression mechanism. In the expander, the refrigerator oil is supplied from an oil reservoir to an expansion mechanism. Internal spaces of a compressor casing and an expander casing communicate with each other through an equalizing pipe. An oil pipe connecting the compressor casing and the expander casing is provided with an oil amount adjusting valve operated on the basis of an output signal of an oil level sensor. When the oil amount adjusting valve is opened, the oil reservoir in the compressor casing and the oil reservoir in the expander casing communicate with each other to allow the refrigerator oil to flow through the oil pipe.

In a compression/expansion unit () serving as a fluid machine, both of a compression mechanism () and an expansion mechanism () are contained in a single casing (). A shaft () coupling the compression mechanism () to the expansion mechanism () has an oil feeding channel () formed therein. Refrigerating machine oil accumulated at the bottom of the casing () is sucked up into the oil feeding channel () and fed to the compression mechanism () and the expansion mechanism (). The refrigerating machine oil fed to the expansion mechanism () is discharged from the expansion mechanism () together with the refrigerant after expansion, flows through the refrigerant circuit and then flows back to the compression mechanism () in the compression/expansion unit ().

Fluid machine

A heat source side circuit () includes a gas-liquid separator () for the separation of refrigerant flowing therein from an expander () into liquid refrigerant and gas refrigerant and a cooling means () for the cooling of liquid refrigerant heading from the gas-liquid separator () to a utilization side circuit (). Since the refrigerant exiting the gas-liquid separator () is in a saturated liquid form, it always changes state to a subcooled state whenever cooled by the cooling means ().

A refrigerant circuit () of an air conditioner () includes a compressor () and an expander (). In the compressor (), refrigerator oil is supplied from an oil reservoir () to a compression mechanism (). In the expander (), the refrigerator oil is supplied from an oil reservoir () to an expansion mechanism (). The inner pressures of the compressor casing () and the expander casing () are the high pressure and the low pressure of the refrigeration cycle, respectively. An oil adjusting valve () is provided in an oil pipe () connecting the compressor casing () and the expander casing (). The oil amount adjusting valve () is operated on the basis of an output signal of an oil level sensor (). When the oil amount adjusting valve () is opened, the refrigerator oil flows from the oil reservoir () in the compressor casing () toward the oil reservoir () in the expander casing () through the oil pipe ().

In a refrigerant circuit (), a compressor () and an expander () are provided separately. An expander casing () is connected to a delivery pipe () of the compressor () and high pressure refrigerant passes through the inside of the expander casing (). Therefore, the compressor casing () and the expander casing () are equalized in their internal pressure. An oil distribution pipe () for connection of an oil sump () of the compressor () and an oil sump () of the expander () is provided with an oil regulating valve (). The oil regulating valve () is controlled in response to a signal outputted from an oil level sensor (). When the oil regulating valve () is opened, the oil sump () within the compressor casing () and the oil sump () within the expander casing () fluidly communicate with each other whereby refrigeration oil travels through the oil distribution pipe ().

Refrigerant sent from a heat source side circuit () to utilization side circuits () is made to be single-phase liquid by using cooling means () or a vapor-liquid separator (). Variable-opening utilization side expansion valves () are provided in the utilization side circuits () so that an expansion process in a refrigeration cycle is performed also in the circuits.

A rotary type expander is provided with two rotary mechanism parts which differ from each other in displacement volume. The outflow side of the first rotary mechanism part of small displacement volume is fluidly connected to the inflow side of the second rotary mechanism part of large displacement volume. The processes by which the volume of a first low-pressure chamber in the first rotary mechanism part decreases and the volume of a second high-pressure chamber in the second rotary mechanism part increases are respectively in sync. Refrigerant at high pressure is first introduced into a first high-pressure chamber of the first rotary mechanism part. Thereafter, this high-pressure refrigerant passes through a communicating passage and then flows by way of the first low-pressure chamber into the second high-pressure chamber while expanding. The after-expansion refrigerant flows out to an outflow port from a second low-pressure chamber of the second rotary mechanism part.

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Osaka, Japan

Masakazu Okamoto