Abstract: A power tool includes a motor, a drive unit driven by the motor, and a trigger switch and a forward-reverse switch each operable by a user. The trigger switch is switchable between an activation state and a deactivation state. The forward-reverse switch switches a motor rotation between forward and reverse. The power tool also includes a control unit that drives the motor based on operation of the trigger switch and allows switching of an operation mode of the power tool between first and second modes. In the first mode, the motor rotation is switched to that selected by the forward-reverse switch. In the second mode, when the activation state is switched to the deactivation state, the motor rotation is switched so that the motor is driven in a direction opposite to the present rotation direction when the trigger switch is activated next.

Abstract: A power tool includes a motor, a drive unit driven by the motor, and a trigger switch and a forward-reverse switch each operable by a user. The trigger switch is switchable between an activation state and a deactivation state. The forward-reverse switch switches a motor rotation between forward and reverse. The power tool also includes a control unit that drives the motor based on operation of the trigger switch and allows switching of an operation mode of the power tool between first and second modes. In the first mode, the motor rotation is switched to that selected by the forward-reverse switch. In the second mode, when the activation state is switched to the deactivation state, the motor rotation is switched so that the motor is driven in a direction opposite to the present rotation direction when the trigger switch is activated next.

Abstract: There is disclosed a heat exchanger capable of suppressing the increase of a pressure drop while improving a non-uniform rate distribution of a fluid. A heat exchanger T of the present invention is constituted of flat plates 1, 2 each having an inflow port 15 of the fluid on one end thereof and an outflow port 16 of the fluid on the other end, and offset type fins 5 provided in the flat plates 1, 2, and includes a fin orthogonal region H where the plate fins 5 cross the flow direction of the fluid from the inflow port 15 to the outflow port 16 at right angles and a fin parallel region V where the plate fins 5 are disposed in parallel with the flow direction of the fluid from the inflow port 15 to the outflow port 16, the fin orthogonal regions H are provided on the sides of the inflow port 15 and the outflow port 16, and the fin parallel region V is provided between the respective fin orthogonal regions H.

Abstract: In a refrigerating machine, a water cooling device having a cooling tower or an ice heat storage tank is provided as a heat exchanger for cooling refrigerant after heat-exchange in a heat-source side heat exchanger between an outdoor expansion valve and the heat-source side heat exchanger.

Abstract: There is provided an exhaust-heat using refrigerating system which can add the function of refrigerant heater, condenser or super-cooler by using exhaust heat. The system comprises a heat pump apparatus 1 equipped with a compressor 12, a first heat exchanger 14, a pressure-reducing device 15 and a second heat exchanger 21, and an absorption type refrigerating machine 5 equipped with a regenerator 51 using exhaust heat as a heat source, a condenser 53, an evaporator 54 and an absorber 55. A third heat exchanger 17 is connected to the first heat exchanger 14 in parallel, and the heat source of the third heat exchanger 17 is achieved from the evaporator 54 of the absorption type refrigerating machine.

Abstract: A heat exchanger is provided in which high heat transfer efficiency has been attained by optimizing the slit array and setting an optimum range for the width of a slit and the spacing between slits. Slits 51 and 52 formed in front of the heat transfer coil 4 and slits 55 and 56 formed behind the heat transfer coil are arranged so as to provide a mutually different length among adjoining partitioned slits in the vertical direction, as well as a mutually different length between directly opposite partitioned slits in the horizontal direction. As a result, the position at which the slit is partitioned is staggered.

Abstract: In a refrigerating machine, a water cooling device having a cooling tower or an ice heat storage tank is provided as a heat exchanger for cooling refrigerant after heat-exchange in a heat-source side heat exchanger between an outdoor expansion valve and the heat-source side heat exchanger.

Abstract: A heat exchanger is provided in which high heat transfer efficiency has been attained by optimizing the slit array and setting an optimum range for the width of a slit and the spacing between slits. Slits 51 and 52 formed in front of the heat transfer coil 4 and slits 55 and 56 formed behind the heat transfer coil are arranged so as to provide a mutually different length among adjoining partitioned slits in the vertical direction, as well as a mutually different length between directly opposite partitioned slits in the horizontal direction. As a result, the position at which the slit is partitioned is staggered. The two slits 53 and 54 formed side by side between heat transfer coil 4 and heat transfer coil 4 are of the same length. For a 7 mm diameter heat transfer coil, the slit width relative to the diameter of the heat transfer coil ranges from 1.2/7 (approximately 0.17) to 2.0/7 (approximately 0.29), and the slit spacing relative to the diameter of the heat transfer coil ranges from 1.

Abstract: There is provided an exhaust-heat using refrigerating system which can add the function of refrigerant heater, condenser or super-cooler by using exhaust heat. The system comprises a heat pump apparatus 1 equipped with a compressor 12, a first heat exchanger 14, a pressure-reducing device 15 and a second heat exchanger 21, and an absorption type refrigerating machine 5 equipped with a regenerator 51 using exhaust heat as a heat source, a condenser 53, an evaporator 54 and an absorber 55. A third heat exchanger 17 is connected to the first heat exchanger 14 in parallel, and the heat source of the third heat exchanger 17 is achieved from the evaporator 54 of the absorption type refrigerating machine.

Abstract: In a method and an apparatus for injecting mixed refrigerant into a refrigerant circuit comprising at least a compressor, a condenser, an expansion device and an evaporator which are connected to one another through a refrigerant pipe, the mixed refrigerant is intermittently injected from a refrigerant bomb at a predetermined position of a low pressure side of the refrigerant circuit while keeping the mixed refrigerant in a liquid state. The intermittent injection operation (amount) of the liquid refrigerant into the refrigerant circuit may be controlled on the basis of the degree of superheat of the mixed refrigerant in the refrigerant circuit.

Abstract: An air conditioner has an outdoor unit and a plurality of room units supplied with a refrigerant from the outdoor unit. The outdoor unit and the room units are connected by a plurality of refrigerant pipes. In a recovery operation for returning refrigerator oil from the room units, the refrigerant pipes and the like to the outdoor unit, the plurality of room units are divided into a plurality of room unit groups, and the recovery operation of the refrigerant is carried out for each of the room unit groups.

Abstract: An object of the invention is to settle an unbalanced refrigerant flow in a heat exchanger thereby to improve a heat exchanging efficiency. In a heat exchanger having a refrigerant conduit provided through a plurality of fins, the refrigerant conduit is divided into a plurality of sets, each consisting of a plurality of parallel conduits, and parallel conduits of a set are put in communication with each other at ends thereof and in communication, through a single passage, with ends of parallel conduits of another set.

Abstract: A refrigeration cycle including a compressor, an indoor heat exchanger, an expansion, an outdoor heat exchanger and a six-way change-over valve having a refrigerant passage through which refrigerant flows in a refrigerant circuit comprising the compressor, the indoor heat exchanger, the expansion and the outdoor heat exchanger, wherein the six-way change-over valve serves to selectively switch the refrigerant passage so that the refrigerant passing in the indoor and outdoor heat exchangers flows in the same direction at any time when the refrigerant cycle is switched to a cooling operation cycle and to a heating operation cycle.

Abstract: In an absorption system hot and cold water supply apparatus for simultaneously supplying hot water and cold water, there is provided a refrigerant blow device for blowing a refrigerant into a refrigerant circulation path, thermo-capacity control device for carring out heating control of a generator by a cold water temperature or a hot water temperature or a combination control of the heating control and a control of a refrigerant flow rate from the generator to and condenser, and control device for controlling the operation of the refrigerant blow device by a cold water exit temperature of an evaporator.