Denso Corporation

Other

Toshio Hirata

Yoshitaka Tomatsu

Yasushi Yamanaka

Satoshi Itoh

Motohiro Yamaguchi

Yasutaka Kuroda

Kunio Iritani

Yoshiyuki Yamauchi

Yukikatsu Ozaki

Tadashi Hotta

Ryo Kobayashi

Keita Honda

Masafumi Nakashima

Kazuya Makizono

An oil content measuring device measures the oil content of a refrigerant in a supercritical or a vapor phase state. A refrigeration system uses the oil content measuring device. The oil content measuring device has an electrostatic capacity measuring device for measuring an electrostatic capacity of the refrigerant containing a refrigerating machine oil, a density measuring device for measuring a density of at least one of the refrigerant and the refrigerating machine oil, a computing device for performing a computation on correlation characteristics between the electrostatic capacity and an oil content which indicates the ratio of the amount of the refrigerating machine oil to the amount of the refrigerant containing the refrigerating machine oil, using the density measured by the density measuring device. An oil content determining device determines an oil content at the measuring time from an electrostatic capacity using the correlation characteristics obtained by the computing device.

Oil content measuring device and refrigeration system using the same

In a vehicle air conditioner with a heat pump cycle having an interior heat exchanger and an exterior heat exchanger, when a frosting on a surface of the exterior heat exchanger is determined and when a temperature of hot water supplied to a heater core is equal to or higher than a predetermined temperature, the exterior heat exchanger is defrosted in a defrosting operation. Accordingly, the defrosting operation can be performed while a sufficient heating can be obtained.

Vehicle air conditioner with defrosting operation of exterior heat exchanger

Heat exchange is performed between a discharge side refrigerant and a suction side refrigerant also at the time of a heating operation. By this, a liquid phase refrigerant containing lubricating oil in the suction side refrigerant is heated by the discharge side refrigerant, and the liquid phase refrigerant is vaporized also at the time of the heating operation, so that the amount of the liquid phase refrigerant sucked into a compressor is decreased. Accordingly, the increase of compression work of the compressor is prevented, and an opening area of an oil return hole can be expanded to such a degree that an optimum amount of lubricating oil is attained at the time of the heating operation.

Heat pump cycle having internal heat exchanger

When the first pressure reducing device is fixed to the accumulator tank and the internal heat exchanger is housed in the accumulator tank , the accumulator, the first pressure reducing device and the internal heat exchanger are integrated into one body. Due to the foregoing, it is possible to eliminate parts for piping to connect the first pressure reducing device with the internal heat exchanger . The mass of the vibration system of the first pressure reducing device including the accumulator tank and the internal heat exchanger is increased. Therefore, even if the valve body in the first pressure reducing device is vibrated, it becomes difficult for other portions to vibrate. Accordingly, it is possible to reduce noise (vibration) generated when refrigerant is decompressed by the first pressure reducing device

Accumulator module

In a vehicle air conditioner having a refrigerant cycle using carbon dioxide as refrigerant, a displacement of a compressor is changed and controlled, so that an air temperature immediately after passing through an evaporator becomes approximately 0&deg; C., and it can prevent a refrigerant amount discharged from the compressor from being larger than a predetermined flow amount. Because the refrigerant amount discharged from the compressor is controlled to be not larger than the predetermined flow amount, it can prevent a high-pressure side refrigerant pressure and a high-pressure side refrigerant temperature from being excessively increased in the refrigerant cycle.

Vehicle air conditioner with refrigerant flow-amount control of compressor

Growing community of inventors

Haguri-gun, Japan

Toshio Hirata