Abstract: An absorption chiller includes a heating medium supply pipe configured to supply a heating medium from a heating medium pipe to a cooling water pipe; a cooling water discharge pipe configured to discharge a cooling water from the cooling water pipe to the heating medium pipe; a control valve provided on the heating medium supply pipe and the cooling water discharge pipe, respectively; and a controller configured to cause the control valve to be opened and to cause the heating medium in the heating medium pipe to be introduced into the cooling water pipe, when a temperature detected by a cooling water temperature detector is equal to or lower than a predetermined temperature, in a wet lay-up state including a state in which a cooling water inlet shut-off valve and a cooling water outlet shut-off valve are closed and the cooling water pipe is filled with the cooling water.

Abstract: An absorption chiller includes a heating medium supply pipe configured to supply a heating medium from a heating medium pipe to a cooling water pipe; a cooling water discharge pipe configured to discharge a cooling water from the cooling water pipe to the heating medium pipe; a control valve provided on the heating medium supply pipe and the cooling water discharge pipe, respectively; and a controller configured to cause the control valve to be opened and to cause the heating medium in the heating medium pipe to be introduced into the cooling water pipe, when a temperature detected by a cooling water temperature detector is equal to or lower than a predetermined temperature, in a wet lay-up state including a state in which a cooling water inlet shut-off valve and a cooling water outlet shut-off valve are closed and the cooling water pipe is filled with the cooling water.

Abstract: A heat exchanger includes: a first heat transfer tube unit including first heat transfer tubes arranged in parallel along a first direction within a horizontal plane; and a second heat transfer tube unit including second heat transfer tubes arranged in parallel with one another along a second direction that intersects the first direction within the horizontal plane. Each of the first heat transfer tubes and the second heat transfer tubes includes: straight portions arranged in parallel in a vertical direction; and one or more curved portions that make end portions of the straight portions communicate with each other. The straight portions of the first heat transfer tube unit and the straight portions of the first heat transfer tube unit are stacked on each other alternately.

Abstract: Disclosed is a technique capable of reducing loss at the time of switching in a diode. A diode disclosed in the present specification includes a cathode electrode, a cathode region made of a first conductivity type semiconductor, a drift region made of a low concentration first conductivity type semiconductor, an anode region made of a second conductivity type semiconductor, an anode electrode made of metal, a barrier region formed between the drift region and the anode region and made of a first conductivity type semiconductor having a concentration higher than that of the drift region, and a pillar region formed so as to connect the barrier region to the anode electrode and made of a first conductivity type semiconductor having a concentration higher than that of the barrier region. The pillar region and the anode are connected through a Schottky junction.

Abstract: A power supply circuit includes inductors, capacitors, and switching elements. Ports are electrically insulated from each other. Two switching elements are alternately switched, and two other switching elements are alternately switched. The inductors are wound such that a magnetic flux is generated in the same direction when a phase difference between the switchings of the switching elements is zero. Duties of the switchings of the switching elements are changed equally, and a phase difference between the switchings is changed.

Abstract: A heat exchanger includes: a first heat transfer tube unit including first heat transfer tubes arranged in parallel along a first direction within a horizontal plane; and a second heat transfer tube unit including second heat transfer tubes arranged in parallel with one another along a second direction that intersects the first direction within the horizontal plane. Each of the first heat transfer tubes and the second heat transfer tubes includes: straight portions arranged in parallel in a vertical direction; and one or more curved portions that make end portions of the straight portions communicate with each other. The straight portions of the first heat transfer tube unit and the straight portions of the first heat transfer tube unit are stacked on each other alternately.

Abstract: Disclosed is a technique capable of reducing loss at the time of switching in a diode. A diode disclosed in the present specification includes a cathode electrode, a cathode region made of a first conductivity type semiconductor, a drift region made of a low concentration first conductivity type semiconductor, an anode region made of a second conductivity type semiconductor, an anode electrode made of metal, a barrier region formed between the drift region and the anode region and made of a first conductivity type semiconductor having a concentration higher than that of the drift region, and a pillar region formed so as to connect the barrier region to the anode electrode and made of a first conductivity type semiconductor having a concentration higher than that of the barrier region. The pillar region and the anode are connected through a Schottky junction.

Abstract: Disclosed is a technique capable of reducing loss at the time of switching in a diode. A diode disclosed in the present specification includes a cathode electrode, a cathode region made of a first conductivity type semiconductor, a drift region made of a low concentration first conductivity type semiconductor, an anode region made of a second conductivity type semiconductor, an anode electrode made of metal, a barrier region formed between the drift region and the anode region and made of a first conductivity type semiconductor having a concentration higher than that of the drift region, and a pillar region formed so as to connect the barrier region to the anode electrode and made of a first conductivity type semiconductor having a concentration higher than that of the barrier region. The pillar region and the anode are connected through a Schottky junction.

Abstract: An electric power conversion circuit comprises U-phase and V-phase switching circuits, a transformer, and an ?-phase switching circuit. A primary winding of a transformer is connected between the U-phase switching circuit and the V-phase switching circuit, and both ends of a secondary winding are connected to the ?-phase switching circuit. The ?-phase switching circuit comprises positive and negative terminals, a half bridge including and two switching devices, and a voltage divider circuit. The half bridge is provided between the positive terminal and the negative terminal, and a common connection point between the two switching devices is connected to one end of the secondary winding. A voltage divider output point of the voltage divider circuit is connected to the other end of the secondary winding.

Abstract: A power supply circuit includes inductors, capacitors, and switching elements. Ports are electrically insulated from each other. Two switching elements are alternately switched, and two other switching elements are alternately switched. The inductors are wound such that a magnetic flux is generated in the same direction when a phase difference between the switchings of the switching elements is zero. Duties of the switchings of the switching elements are changed equally, and a phase difference between the switchings is changed.

Abstract: A power supply system includes first and second DC power supplies and a power converter having first to fifth semiconductor elements and first and second reactors. The first and fourth semiconductor elements are electrically connected between a first node and a second node, and a first power line, respectively. Second and third switching elements are electrically connected between the first node and the second node, and a second power line, respectively. A fifth switching element is electrically connected between the first node and the second node. The first reactor is electrically connected in series with the first DC power supply, between the first node and the second power line. The second reactor is electrically connected in series with the second DC power supply, between the first power line and the second node.

Abstract: The present invention provides a power conversion circuit system in which a circulating current can be reduced by accurately detecting the circulating current, to thereby improve efficiency in power conversion. The power conversion circuit system includes a power conversion circuit composed of a primary conversion circuit having left and right arms and a secondary conversion circuit having left and right arms, and a control circuit for controlling switching of switching transistors in the primary and secondary conversion circuits. The control circuit detects the circulating current at at least one of timings lagged by ?/2+?/2 from at least either a peak timing or a valley timing in a carrier counter where ? represents a difference in phase between the primary and secondary conversion circuits, and performs feedback control for reducing the detected circulating current to zero.

Abstract: An electric power conversion circuit system for reducing core loss in a transformer particularly during light loading and improving conversion efficiency during light loading comprising an electric power conversion circuit composed of a primary side conversion circuit having a left arm and a right arm and a secondary side conversion circuit having a left arm and a right arm, and a control circuit for controlling switching of switching transistors of the first side conversion circuit and the secondary side conversion circuit. When the output voltage is at a relatively light load, the control circuit controls to change the duty of the transmitting side among the primary side conversion circuit and the secondary side conversion circuit and controls to change the half-bridge phase differences of the left arm and the right arm of the primary side conversion circuit and the secondary side conversion circuit, respectively.

Abstract: Disclosed is a technique capable of reducing loss at the time of switching in a diode. A diode disclosed in the present specification includes a cathode electrode, a cathode region made of a first conductivity type semiconductor, a drift region made of a low concentration first conductivity type semiconductor, an anode region made of a second conductivity type semiconductor, an anode electrode made of metal, a barrier region formed between the drift region and the anode region and made of a first conductivity type semiconductor having a concentration higher than that of the drift region, and a pillar region formed so as to connect the barrier region to the anode electrode and made of a first conductivity type semiconductor having a concentration higher than that of the barrier region. The pillar region and the anode are connected through a Schottky junction.

Abstract: A power supply system includes first and second DC power supplies and a power converter having first to fifth semiconductor elements and first and second reactors. The first and fourth semiconductor elements are electrically connected between a first node and a second node, and a first power line, respectively. Second and third switching elements are electrically connected between the first node and the second node, and a second power line, respectively. A fifth switching element is electrically connected between the first node and the second node. The first reactor is electrically connected in series with the first DC power supply, between the first node and the second power line. The second reactor is electrically connected in series with the second DC power supply, between the first power line and the second node.

Abstract: An electric power conversion circuit comprises U-phase and V-phase switching circuits, a transformer, and an ?-phase switching circuit. A primary winding of a transformer is connected between the U-phase switching circuit and the V-phase switching circuit, and both ends of a secondary winding are connected to the ?-phase switching circuit. The ?-phase switching circuit comprises positive and negative terminals, a half bridge including and two switching devices, and a voltage divider circuit. The half bridge is provided between the positive terminal and the negative terminal, and a common connection point between the two switching devices is connected to one end of the secondary winding. A voltage divider output point of the voltage divider circuit is connected to the other end of the secondary winding.

Abstract: A magnetically coupled reactor includes a coupled core member, a first coil, and a second coil. The coupled core member includes a first core and a second core made of a magnetic material and disposed to face each other, a coil channel, and a sheet-like magnetic body by which a coupling portion between cores is put between the first core and the second core at an outer portion of the first and second cores. Each coil is wound around a leg through the coil channel in a lap winding manner such that the coils are overlapped on top of each other in the coil channel when seen in an axial direction. The sheet-like magnetic body extends from the coupling portion between coils into the coil channel and includes a portion arranged between coils located between the coils in the axial direction.

Abstract: Disclosed is a technique capable of reducing loss at the time of switching in a diode. A diode disclosed in the present specification includes a cathode electrode, a cathode region made of a first conductivity type semiconductor, a drift region made of a low concentration first conductivity type semiconductor, an anode region made of a second conductivity type semiconductor, an anode electrode made of metal, a barrier region formed between the drift region and the anode region and made of a first conductivity type semiconductor having a concentration higher than that of the drift region, and a pillar region formed so as to connect the barrier region to the anode electrode and made of a first conductivity type semiconductor having a concentration higher than that of the barrier region. The pillar region and the anode are connected through a Schottky junction.

Abstract: An electric power conversion circuit system for reducing core loss in a transformer particularly during light loading and improving conversion efficiency during light loading comprising an electric power conversion circuit composed of a primary side conversion circuit having a left arm and a right arm and a secondary side conversion circuit having a left arm and a right arm, and a control circuit for controlling switching of switching transistors of the first side conversion circuit and the secondary side conversion circuit. When the output voltage is at a relatively light load, the control circuit controls to change the duty of the transmitting side among the primary side conversion circuit and the secondary side conversion circuit and controls to change the half-bridge phase differences of the left arm and the right arm of the primary side conversion circuit and the secondary side conversion circuit, respectively.

Abstract: The present invention provides a power conversion circuit system in which a circulating current can be reduced by accurately detecting the circulating current, to thereby improve efficiency in power conversion. The power conversion circuit system includes a power conversion circuit composed of a primary conversion circuit having left and right arms and a secondary conversion circuit having left and right arms, and a control circuit for controlling switching of switching transistors in the primary and secondary conversion circuits. The control circuit detects the circulating current at at least one of timings lagged by ?/2+?/2 from at least either a peak timing or a valley timing in a carrier counter where ? represents a difference in phase between the primary and secondary conversion circuits, and performs feedback control for reducing the detected circulating current to zero.