The present invention relates to a gas heat pump and a control method therefor and, according to the present invention, the method for controlling a gas heat pump, which comprises an ignition plug and a gas engine having an engine combustion unit including a plurality of combustion spaces, may include: a target setting step of setting a target ignition energy amount on the basis of a refrigerant load amount determined according to a driving condition of the gas heat pump; an ignition step of igniting fuel injected into the combustion spaces; a comparison step of comparing an output energy amount emitted in the ignition step with a target ignition energy amount set in the target setting step; and a step of changing an energy amount required to ignite the fuel when the output energy amount and the target ignition energy amount do not coincide in the comparison step.

A refrigeration cycle apparatus in which a compressor, a heat-source-side heat exchanger, a decompressor, and a use-side heat exchanger are connected by pipes to allow refrigerant to be circuited as a refrigeration cycle. The refrigeration cycle apparatus includes a controller which controls an operation of each of devices. The controller sets an operation mode to a specific operation mode for determining where abnormality occurs based on states of the compressor, the heat-source-side heat exchanger, the decompressor and the use-side heat exchanger in the case where an operating state of one of a plurality of element devices to be controlled by the controller is changed from a first state to a second state, the element devices being included in the compressor, the heat-source-side heat exchanger, the decompressor and the use-side heat exchanger.

An air conditioning apparatus includes: an outdoor unit configured to circulated refrigerant; a first pipe and a second pipe that are connected to the outdoor unit; an indoor unit configured to circulate water; and a heat exchange device that connects the outdoor unit to the indoor unit. The heat exchange device includes a first heat exchanger and a second heat exchanger that are each configured to perform heat exchange between the refrigerant and the water, a plurality of connection pipes, a bypass pipe configured to guide the refrigerant passing through the first heat exchanger to the second heat exchanger, and a bypass valve installed at the bypass pipe.

An air conditioning system can be toggled between a heating mode, in which heat is withdrawn from a source (e.g., a geothermal source) and deposited into a conditioned space (e.g., a building), and a cooling mode, in which heat is withdrawn from the conditioned space and deposited into the source. The air conditioning system uses a combination of efficiency-enhancing technologies, including injection of superheated vapor into the system's compressor from an economizer circuit, adjustable compressor speed, the use of one or coaxial heat exchangers and the use of electronic expansion valves that are continuously adjustable from a fully closed to various open positions. A controller may be used to control the system for optimal performance in both the heating and cooling modes, such as by disabling the economizer circuit and vapor injection when the system is in the cooling mode.

A cooling and heating system for a motor vehicle comprises a heat pump, a controller, a low temperature radiator in thermal communication with the heat pump, a passenger cabin heat exchanger in thermal communication with the heat pump, and a defrost system comprising a bypass coolant loop in selective fluid communication with the low temperature radiator. When in the heating mode, the controller opens a solenoid valve and activates a coolant heater in the bypass coolant loop upon detecting operation of the heat pump outside of a predetermined normal operating range and upon detecting an ambient temperature below a predetermined temperature. The controller de-activates the coolant heater upon detecting operation of the heat pump within the predetermined normal operating range. The controller may also de-activate close the solenoid upon detecting operation of the heat pump within the predetermined normal operating range.

An air-conditioning apparatus includes a refrigerant circuit, a heat medium circuit, and a controller. In the refrigerant circuit, a compressor, a heat-source-side heat exchanger, an expansion unit, and a load-side heat exchanger are connected by refrigerant pipes, and refrigerant flows. The heat-source-side heat exchanger causes heat exchange to be performed between the refrigerant and a heat-source heat medium. The load-side heat exchanger causes heat exchange to be performed between the refrigerant and a load heat medium, and refrigerant flows. In the heat medium circuit, a flow control valve that regulates the flow rate of the heat-source heat medium and the heat-source-side heat exchanger are connected by a heat medium pipe, and the heat-source heat medium flows. The controller includes a storage unit that stores data indicating a defined maximum flow rate and a defined minimum flow rate of the heat-source heat medium that flows in the heat medium circuit.

The invention provides a highly reliable refrigeration apparatus configured to cool the interior of a casing of a heat source unit by means of a refrigerant and can reduce a possibility that liquid compression is caused by supply of the refrigerant to a heat exchanger for cooling the interior of the casing. An air conditioner (10) includes a heat source unit (100), a utilization unit (300) having a utilization heat exchanger (310) and constituting a refrigerant circuit (50) along with the heat source unit, and a controller. The heat source unit includes a compressor (110), a heat source-side heat exchanger (140) configured to cause heat exchange between a refrigerant and a heat source, a casing, a cooling heat exchanger (160) supplied with the refrigerant and configured to cool the interior of the casing, and a valve (162) configured to switch to supply or not to supply the cooling heat exchanger with the refrigerant. The controller configured to open or close the valve assesses, before the refrigerant is supplied to the cooling heat exchanger, whether or not the refrigerant flowing from the cooling heat exchanger toward the compressor comes into a wet state when the refrigerant is supplied, and determines whether or not to open the valve in accordance with an assessment result.

It is provided a refrigeration apparatus that uses liquid fluid as a heat source and is highly reliably configured to reduce the occurrence of dew condensation and freezing at a utilization unit during cooling operation in which a liquid fluid heat exchanger in a heat source unit functions as a radiator. An air conditioner (10) includes a heat source unit (100) having a compressor (110), a first heat exchanger (140) configured to cause heat exchange between a refrigerant and liquid fluid, a second heat exchanger (160) configured to cause heat exchange between the refrigerant and air, and a valve (162) configured to switch to supply or not to supply the second heat exchanger with the refrigerant, a utilization unit (300) constituting a refrigerant circuit (50) along with the heat source unit, and a controller (406) configured to control to operate the compressor and to open or close the valve (162). The controller opens the valve (162) to supply the second heat exchanger with the refrigerant to cause the second heat exchanger to function as a heat absorber when assessing that the refrigerant sent to the utilization unit needs to be decreased in quantity during cooling operation in which the first heat exchanger functions as a radiator.

A heat exchange apparatus includes a first heat exchanger configured to transfer heat between a refrigerant and another medium, a plurality of second heat exchangers configured to transfer heat between the refrigerant and the liquid, a compressor configured to pressurize the refrigerant and a plurality of expansion devices for each of the plurality of second heat exchangers and configured to expand the refrigerant pressurized by the compressor, wherein the refrigerant flows through the plurality of second heat exchangers in parallel, and the liquid flows through the plurality of second heat exchangers in series.

A heat transfer medium liquid circulation flow channel having a first heat exchange unit exchanging heat to a second heat exchange unit is provided, and a fixed amount of first heat transfer medium liquid circulates therein. A feed pipe couples heat source holding second heat transfer medium liquid having temperature difference from the first medium liquid to the heat transfer medium liquid circulation flow channel. The feed pipe is coupled to an inlet end side of the first heat exchange unit and a discharge pipe is coupled to an outlet end side thereof. A necessary amount of second medium liquid is supplied to the inlet end side via the feed pipe so that a detected temperature of the first medium liquid in the outlet end maintains required set temperature. The same amount of the first medium liquid as the supplied second medium liquid is discharged out of the discharge pipe.