摘要:
In an air conditioner for a vehicle, in a heating operation for heating a vehicle compartment, when heating capacity is obtained by flowing a coolant through an inside of an indoor heat exchanger, the coolant flows directly in the inside of the indoor heat exchanger to heat air to be supplied to the vehicle compartment. In contrast, when the heating capacity is not obtained by flowing the coolant through the inside of the indoor heat exchanger, the coolant flows through a first water-refrigerant heat exchanger and a refrigerant in a heat pump cycle circulates so that heat of the coolant is absorbed by the refrigerant in the first water-refrigerant heat exchanger, and the air is heated in the indoor heat exchanger by using heat of the refrigerant that has absorbed the heat of the coolant.
摘要:
A refrigerating system of a gas injection type having first and second stage pressure reducers 3 and 5, between which a separator 4 is arranged, and a conduit 10 for introduction of a gaseous refrigerant separated at a separator 4 into a compressor 1. A by-pass conduit 11 is connected to a refrigerating system so that the second stage pressure reducer 5 is by-passed. An ON-OFF control valve 12 is arranged in the by-pass conduit. The control valve 12 is switched to an opened condition during a low load of the air conditioning system, which makes a pressure difference low between the outlet of the separator 4 and an evaporator 6, which prevent gas injection from being executed. A control valve can also be arranged in a gas injection conduit 10, which controls an amount of the gas injection in accordance with a ratio (compression ratio) of an outlet pressure to an intake pressure in such a manner a reduction of a gas injection amount is obtained when a value of the compression ratio is lower than a predetermined value, thereby preventing over-compression from occurring.
摘要:
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.
摘要:
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.
摘要:
In an ejector cycle having an ejector, a decompression amount of refrigerant between a gas-liquid separator and an evaporator is adjusted by a differential pressure control valve, so that a pressure increasing amount in a pressure increasing portion of the ejector is controlled to be equal to or lower than a predetermined amount. Therefore, a suction pressure of refrigerant to be sucked to the compressor can be restricted from being excessively increased in accordance with the increase of the pressure increasing amount in the ejector, and it can prevent heat radiating capacity of a radiator from being decreased. Thus, a sufficient cooling capacity can be always obtained in the ejector cycle.
摘要:
The supercritical refrigerating circuit has a first pressure reducing valve for reducing pressure of refrigerant flows into a first evaporator and a second pressure reducing valve for reducing pressure of refrigerant flows into a second evaporator. The first pressure reducing valve further controls refrigerant pressure at an outlet of a gas cooler. Accordingly, the supercritical refrigerant circuit is controlled without increasing the number of the pressure reducing valve.
摘要:
A gas-liquid separator for a heat pump type air conditioning system using a gas-injection cycle, which system can switch its mode of operation between heating and cooling modes, includes a reservoir for receiving refrigerant in a gas-liquid two-phase flow, an exit port which opens at a upper portion of the reservoir and allows a refrigerant gas to flow out of the reservoir, first and second ports which are provided at a upper part within the reservoir above the level of a refrigerant liquid and allows the refrigerant to flow into and out of the reservoir. A first refrigerant path for allowing the first port to fluidly communicate with the refrigerant liquid in the reservoir, a second refrigerant path for allowing the first port to fluidly communicate with the refrigerant gas above the level of the refrigerant liquid in the reservoir, a third refrigerant path for allowing the second port to fluidly communicate with the refrigerant liquid in the reservoir, and a fourth refrigerant path for allowing the second port to fluidly communicate with the refrigerant gas above the level of the refrigerant liquid in the reservoir are provided within the reservoir. The second and third refrigerant path open when a refrigerant enters the reservoir through the first port, and the first and fourth refrigerant path open when a refrigerant enters the reservoir through the second port.
摘要:
In an ejector, a nozzle includes a nozzle tapered section having an inner passage with a radial dimension reduced toward a nozzle outlet port, and a needle having a needle tapered section disposed in the inner passage. The needle tapered section has a cross sectional area reduced toward a downstream end of the needle, and the downstream end of the needle is positioned at a downstream side with respect to the nozzle outlet port. In addition, the nozzle tapered section has a taper angle (φ1) which is equal to or greater than a taper angle (φ2) of the needle tapered section. Therefore, a boundary face on the outside of a nozzle jet flow becomes in a balanced natural shape, and is controlled in accordance with an operating condition. Thus, the ejector cycle can be operated while keeping high efficiency, regardless of the thermal load of the ejector cycle.
摘要:
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.
摘要:
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.