摘要:
An air-conditioning apparatus including a bypass pipe that branches off from a portion of a refrigerant pipe located at the refrigerant inlet side of a plurality of heat medium heat exchangers. The bypass pipe connects the refrigerant inlet side with a refrigerant outlet side of each of the plurality of heat medium heat exchangers in the cooling only operation mode. A flow switching device, disposed in the refrigerant pipe, on the outlet side of each of the plurality of heat medium heat exchangers and another flow switching device, disposed in the bypass pipe, on the refrigerant outlet side of each of the plurality of heat medium heat exchangers, cause refrigerant to flow in the bypass pipe in the cooling only operation mode.
摘要:
According to one embodiment, a testing device includes a signal generator that generates a first signal output to a device under test, a channel selector provided after the signal generator and configured to select one of a plurality of channels, a signal receiver that receives the second signal supplied from the device under test, a correction value calculator that calculates a correction value for calibrating loss of a respective one of the channels, wherein the correction value calculator calculates a correction value for calibrating loss of a respective one of the channels included in the channel selector, based on a signal level received by the signal receiver via a loopback channel, when a calibration-level output state indicating a state where a signal level of the first signal generated by the signal generator reaches a predetermined transmission reference level of calibration is assumed.
摘要:
An air-conditioning apparatus includes refrigerating cycle systems each connecting a compressor for compressing a refrigerant, a refrigerant flow path switching device, a heat source side heat exchanger for exchanging heat for the refrigerant, an expansion device for adjusting the pressure of the refrigerant, and heat exchangers related to heat medium which exchanges heat between the refrigerant and heat medium different from the refrigerant, by piping so as to constitute refrigerant circuits; and heat medium side systems each connecting pumps for circulating the heat medium for the heat exchangers related to heat medium, use side heat exchangers for exchange heat between the heat medium and air of an air-conditioning target space and heat medium flow switching systems for switching the heat medium which passes through each heat exchangers related to heat medium to each use side heat exchanger, by piping so as to constitute a heat medium circulation circuit.
摘要:
An air-conditioning apparatus includes a heat medium side device with plural pumps for circulating the heat medium related to the heating or the cooling of plural intermediate heat exchangers. Plural use side heat exchangers exchange heat between the heat medium and air. Plural flow path switching valves switch the flow path for supplying the heat medium related to a selected system among the heating media circulating in plural systems to each use side heat exchanger. A relay unit side control device controls the flow path switching valves so as to circulate the heat medium between the use side heat exchanger causing the heat medium to absorb the heat and the use side heat exchanger causing the heat medium to emit the preferentially set heat, when it is determined that it is impossible to perform the heating or the cooling of the heat medium by the intermediate heat exchanger.
摘要:
In the case of a heating operation in which a use side heat exchanger functions as a condenser when the outside air has a predetermined low temperature, a low-outside-air-temperature heating operation start mode is executed in which, while a refrigerant, as discharged from a compressor, flows into the use side heat exchanger, the refrigerant, upon flowing into the injection pipe, merges with a part of the refrigerant discharged from the compressor, which has traveled through the connecting pipe and has transferred heat in the heat source side heat exchanger, and a merged refrigerant is supplied to the injection port of the compressor, and thereafter a low-outside-air-temperature heating operation mode is executed in which the refrigerant, as discharged from the compressor, is supplied to the injection port of the compressor via the injection pipe while flowing into the use side heat exchanger.
摘要:
An air-conditioning apparatus includes a suction-injection pipe that introduces a refrigerant in a liquid or two-phase state into a suction side of a compressor, an expansion device that is arranged at the suction-injection pipe, and a controller that regulates the suction-injection flow rate of a refrigerant introduced into the suction side of the compressor through the suction-injection pipe by controlling the opening degree of the expansion device.
摘要:
An illumination apparatus including: a power supply circuit which outputs a DC power obtained by rectifying an AC voltage and stepping up the rectified voltage; a light source unit having semiconductor light emitting elements turned on by the DC power; and a housing formed of a conductive material that is grounded through a ground path and on which the power supply circuit and the light source unit are mounted. When one of power feed lines is cut off, the light emitting elements are supplied with an AC power from an AC power source through the ground path and a stray capacitance formed between the light source unit and the housing, and a forward voltage of the light emitting elements has a light emission level hardly recognizable.
摘要:
An air-conditioning apparatus includes a refrigerant circuit including a low-pressure shell structure compressor into which a refrigerant flowing through an injection pipe flows, a first heat exchanger, a second heat exchanger, a first expansion device, a refrigerant flow switching device, and a second expansion device configured to allow the refrigerant which has passed through the first expansion device and flows from the second heat exchanger to the first heat exchanger to have an intermediate pressure, the compressor, the first heat exchanger, the second heat exchanger, the first expansion device, the refrigerant flow switching device, and the second expansion device being connected by pipes to constitute the refrigerant circuit, and further includes a controller that controls an amount of refrigerant flowing through the injection pipe into a compression chamber. A part of a high-pressure refrigerant flowing from the first heat exchanger to the second heat exchanger flows through the injection pipe.
摘要:
An air-conditioning apparatus that includes a refrigeration cycle in which a compressor, a heat-source side heat exchanger, an expansion unit, and a load-side heat exchanger are included and are connected with refrigerant pipes, includes cutoff units capable of flowing or cut off a refrigerant circulating in the refrigeration cycle; a detection unit detecting leaking of the refrigerant on the basis of a resistance that changes with densities of plural kinds of leaked refrigerants; a concentration calculation unit calculating a concentration of a refrigerant that has leaked, on the basis of the resistance of the detection unit; a concentration detection unit outputting a calculation result of the concentration calculation unit in order that the calculation result is used for controlling the cutoff units; and a cutoff control unit controlling the cutoff units on the basis of an output of the concentration detection unit.
摘要:
In an air-conditioning apparatus including a refrigerant circulating circuit A and a heat medium circulating circuit B that performs passing of heat to and from the refrigerant circulating circuit A, the heat medium circulating circuit is a closed circuit, the maximum pump head Pp of a pump of the heat medium circulating circuit is 150 kPa or more, and a pressure near at least a suction side of the pump is set to a charged pressure that is maintained equal to or higher than the atmospheric pressure during operation of the pump.