Hitachi, Ltd.

Hitachi Appliances, Inc

Masahiko Gommori

Hiroaki Hata

Tadashi Iizuka

Reishi Naka

Hiroshi Kogure

Yoshiharu Homma

Katsumi Fukuda

Tetsunobu Okamura

Kenichi Saitoh

Haruko Ashida

Takeo Ozawa

Kazuhiro Endoh

Akihiko Ishiyama

Taichi Tanaami

Katsutoshi Shinohara

Takahiro Kaneko

Kouichi Fukushima

Junichi Takagi

A heat-pump hot water supply apparatus, for dissolving problems of delaying in heating rise-up time when re-starting, and ill influences upon starting characteristics, due to liquid refrigerant residing in an evaporator when the operation is stepped, within a heat-pump circuit thereof, comprises a heat-pump refrigerant circuit, in which a compressor, a water/refrigerant heat exchanger, a refrigerant adjusting valve, and an evaporator, in series, through refrigerant pipes, a direct hot-water supply circuit, into which is supplied hot water heated, obtained by heating water supplied from an outside via a water pipe by means the water/refrigerant heat exchanger, and a compressor operation controller means for stopping the compressor and also closing the refrigerant adjusting valve when the compressor stops the operation thereof, and for re-starting the compressor after opening the refrigerant adjusting valve when the compressor starts the operation, again, wherein the refrigerant within the evaporator is collected to the compressor side when the operation is stopped, and after stopping, front and back of the evaporator is brought into a sealed condition by means of a refrigerant adjusting valve and a back-flow preventing valve, thereby preventing the refrigerant from residing within the evaporator.

Heat-pump hot water supply apparatus

A hot-water supply system heats water through heat exchange between high-temperature refrigerant of a heat pump circuit and water of a water circulating circuit. The system is an instantaneous water heater unit for instantaneously heating, at a water heat exchanger, water supplied through a water supply pipe and supplying hot water to a using end unit. Therefore, a large-capacity hot-water storage tank is not needed. Sufficient heat of condensation to heat water can not be produced, because pressure conditions of the heat pump circuit is not stabilized just after the start of operation. Therefore, during a short period of rising time, hot water stored in a hot-water supply tank and water from the water heat exchanger are mixed and the mixture is supplied to keep the hot water at a preset temperature. Therefore, it is possible to use a smaller hot-water supply tank.

Heat pump hot-water supply system

The object of the present invention is to provide a compact lightweight heat pump hot-water supply system. The hot-water supply system heats water through heat exchange between high-temperature refrigerant of a heat pump circuit and water of a water circulating circuit. The system is an instantaneous water heater unit for instantaneously heating, at a water heat exchanger, water supplied through a water supply pipe and supplying hot water to a using end unit. In this system, therefore, large-capacity hot-water storage tank in conventional systems is no longer needed. Sufficient heat of condensation to heat water can not be produced, because pressure conditions of the heat pump circuit is not stabilized just after the start of operation. Therefore, during a short period of rising time, hot water stored in a hot-water supply tank and water from the water heat exchanger are mixed and the mixture is supplied to keep the hot water at a preset temperature. It is, therefore, possible to downsize the hot-water supply tank.

A lubricant composition comprising as a base oil one or more ester oils, alkylbenzene oils and mineral oils, and a glycidyl ether compound having at least two epoxy groups is miscible in hydrofluorocarbon and hydrochlorofluorocarbon refrigerants such as R134a, etc. as replacing refrigerants of R12 and provides a stable operation of refrigeration compressor for a long period of time without causing corrosion and wear of a sliding portion of the compressor.

Refrigeration apparatus containing lubricant composition

A refrigerator comprises a compressor for compressing and discharging a coolant, a first heat exchanger which performs heat exchange between the compressed coolant from the compressor and the atmosphere to cool the compressed coolant, an adiabatic expansion orifice where the compressed and cooled coolant after passing the first heat exchanger is adiabatically expanded, and a second heat exchanger which performs heat exchange between the adiabatically expanded coolant and the air in refrigerating chambers so as to cool the air in the refrigerating chambers by the coolant and to heat the coolant by the air in the refrigerating chambers. The refrigerator further includes a third heat exchanger which performs heat exchange between water produced when frost attached on the refrigerating chambers is melted and the compressed coolant discharged from the compressor so as to heat and evaporate the water, and a fourth heat exchanger which performs heat exchange between the compressed coolant and the atmosphere so as to cool the compressed coolant. The third heat exchanger and the fourth heat exchanger are connected in series so that the compressed coolant discharged from the compressor is supplied to the first heat exchanger after it passes and is cooled by both the third and fourth heat exchangers.

Refrigerator

Lubricant for refrigeration compressors

Lubricant composition, refrigeration apparatus containing same and

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Ohira, Japan

Masahiko Gommori