Denso Corporation

Other

Yasutaka Kuroda

Shin Nishida

Yasushi Yamanaka

Yoshitaka Tomatsu

Motohiro Yamaguchi

Satoshi Itoh

Yukikatsu Ozaki

Mitsuo Inagaki

Sadahisa Onimaru

Hisayoshi Sakakibara

Tadashi Hotta

Toshio Hirata

Nobuharu Kakehashi

Kenichi Fujiwara

Hiroshi Kishita

Yoshiyuki Yamauchi

Ryo Kobayashi

Masafumi Nakashima

Kazuya Makizono

Yoshinori Murata

A two-stage pressure buildup refrigeration cycle apparatus has a low-pressure side compressor, a high-pressure side compressor, and a controller. The controller controls, for improving a COP, the low-pressure side compressor and the high-pressure side compressor in a COP improving operation mode in which a refrigerant discharge capacity of one of the low-pressure side compressor and the high-pressure side compressor is set based on a refrigerant discharge capacity of an other of the low-pressure side compressor and the high-pressure side compressor, when a required level of a refrigeration performance is low. The controller controls the low-pressure side compressor and the high-pressure side compressor in a high performance operation mode in which a refrigerant discharge capacity of the high-pressure side compressor is increased after increasing a refrigerant discharge capacity of the low-pressure side compressor, when the required level of the refrigeration performance is high.

Two-stage pressure buildup refrigeration cycle apparatus

An automotive air conditioning system has a primary hot water circuitlocated on a side where a vehicle installed heat generatoris located and a secondary hot water circuitwhich includes a hot water type heater corefor heating passenger compartment outlet air, whereby when in a heating mode, in the event that a coolant temperature TWof the primary hot water circuit is lower than a coolant temperature TWof the secondary hot water circuit, an opening and closing valveis closed, whereas an opening and closing valveis opened, so that a state is created in which the hot water circuitsare separated from each other. On the other hand, in the event that the coolant temperature TWof the primary hot water circuit becomes higher than the coolant temperature TWof the secondary hot water circuit, the opening and closing valveis opened, whereas the opening and closing valveis closed, so that a state is created in which the hot water circuitsare connected to each other.

Automotive air conditioning system

In a refrigerant cycle system, refrigerant compressed in a first compressor is cooled and condensed in a radiator, and refrigerant from the radiator branches into main-flow refrigerant and supplementary-flow refrigerant. The main-flow refrigerant is decompressed in an expansion unit while expansion energy of the main-flow refrigerant is converted to mechanical energy. Thus, the enthalpy of the main-flow refrigerant is reduced along an isentropic curve. Therefore, even when the pressure within the evaporator increases, refrigerating effect is prevented from being greatly reduced in the refrigerant cycle system. Further, refrigerant flowing into the radiator is compressed using the converted mechanical energy. Thus, coefficient of performance of the refrigerant cycle system is improved.

Refrigerant cycle system with expansion energy recovery

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 refrigerant cycle system, a control unit controls both a refrigerant amount discharged from a compressor and an opening degree of a pressure control valve so that theoretical efficiency of a super-critical refrigerant cycle and efficiency of the compressor are improved. Therefore, the effective coefficient of performance of the refrigerant cycle is improved, while necessary capacity of components of the refrigerant cycle is obtained.

Refrigerant cycle system with super-critical refrigerant pressure

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

An automotive climate control system is disclosed. As long as an ignition switch is off, a bypass ( ) is closed (in this state, a ratio between warm air and cool air is a maximum when the automotive climate control system is activated.), the blowout is set to defrost mode and the introduced air is set to external air mode regardless of the preceding modes of blowout and introduced air (when the ignition switch is on). As a result, the refrigerant leaking from an evaporator ( ) flows to an external air inlet ( ) smaller in air resistance. Even in the case where the ignition switch is off, therefore, the leaking refrigerant is prevented from flowing into the cabin.

Automotive climate control system

When a compressor is stopped, a refrigerant passage in which refrigerant flows from a radiator to an evaporator is closed by a pressure control valve. Accordingly, even after the compressor is stopped, a high-pressure side pressure can be prevented from decreasing. This does not cause increased manufacturing cost of a supercritical refrigerating system.

Supercritical refrigerating system

The supercritical refrigerating apparatus has refrigerant bypass means for bypassing a heat exchanger according to a physical value of the refrigerant. Therefore, the temperature of refrigerant on a suction side of the compressor becomes lower than that of refrigerant sucked into the compressor via the heat exchanger. As a result, the refrigerant temperature in a refrigerant passage extending from a suction side to a discharge side of the compressor is decreased, thereby preventing breakage of the compressor.

Supercritical refrigerating apparatus

In a CO.sub.2 refrigerant cycle, a lubricating oil for a compressor has a compatibility relative to CO.sub.2 refrigerant, and the compatibility of the lubricating oil relative to the CO.sub.2 refrigerant at a pressure lower than a critical pressure of the CO.sub.2 refrigerant is lower than that at a pressure higher than the critical pressure of the CO.sub.2 refrigerant. Thus, in a low-pressure side such as an accumulator of the CO.sub.2 refrigerant cycle, because a liquid lubricating oil is separated with a liquid CO.sub.2 refrigerant, only the lubricating oil can be readily introduced into a suction side of the compressor, and it can prevent the liquid CO.sub.2 refrigerant from being sucked into the compressor. As a result, it can prevent a damage to the compressor while preventing deterioration of coefficient of performance of the CO.sub.2 refrigerant cycle.

Refrigerant cycle

An air conditioning system having an evaporator 8 at a location upstream from a compressor. When a compressor is stopped, a refrigerant inlet is closed by an electromagnetic valve 28 and a refrigerant outlet is closed by a check valve 29. A pressure in the closed passageway is detected by a pressure sensor 22. A leakage of refrigerant at the evaporator is reliably detected, which allows the leakage of the refrigerant to be quickly noticed.

Air conditioning system

A thermal expansion valve for automotive coolant systems which is significantly more compact than previously developed expansion values. The housing of the expansion valve is divided into a first housing formed in a cylindrical shape with a bottom and a second housing formed in a columnar shape. The first housing is fit into the second housing, and both are integrally connected to each other. A temperature sensing mechanism having a temperature sensing chamber and an expansion mechanism for adjusting an opening degree of a throttle passage in accordance with an evaporator outlet temperature sensed by the temperature sensing means are disposed in the second housing. First and fourth joint portions connected to inlet and outlet refrigerant pipes of the evaporator, respectively, are at the bottom of the first housing. On the other hand, second and third joint portions connected to a compressor suction side refrigerant pipe and a high-pressure side refrigerant pipe from a receiver, respectively, are at an outer surface of the second housing. In this manner the overall size of the expansion valve is reduced considerably, thus saving valuable space in an engine compartment of a vehicle.

Growing community of inventors

Anjo, Japan

Yasutaka Kuroda