Abstract: Provided is a refrigerator system with which refrigerators can be operated efficiently. This refrigerator system has: an upstream refrigerator having a first compressor that compresses a refrigerant, a first condenser that condenses the refrigerant compressed by the first compressor, and a first evaporator that evaporates the refrigerant condensed by the first condenser and cools cold water; a downstream refrigerator having a second compressor that compresses a refrigerant, a second condenser that condenses the refrigerant compressed by the second compressor, and a second evaporator that evaporates the refrigerant condensed by the second condenser and cools the cold water that has passed through the first evaporator; and a higher-level control device that controls the operation of the upstream refrigerator and the downstream refrigerator. The first compressor is a variable-speed device, and the second compressor is a constant-speed device.

Abstract: To swiftly start, at the time of power recovery after a power failure, heat source machines, the number of which is equal to the number of machines before the power failure, without including an uninterruptible power supply in an apparatus for controlling the number of machines that is adapted to control the number of heat source machines. There is provided a heat source system, in which a host control device (20) includes a nonvolatile first storage unit (22) that stores the number of heat source machines in operation immediately before the power failure. When power is recovered, control on the number of heat source machines at the time of power recovery is performed in accordance with the number of heat source machines stored in the first storage unit (22).

Abstract: A machine quantity controlling device which controls a quantity of a heat source device to operate in a heat source system including a first heat source device and a second heat source device, the first heat source device being a waste heat recovery type absorption chiller, the second heat source device other than a waste heat recovery type absorption chiller, the machine quantity controlling device including an acquisition unit that obtains a waste heat utilization maximum load which is a maximum load when the first heat source device receives only supply of the waste heat; a determination unit that determines a predetermined load range from the waste heat utilization maximum load to be a first optimal load range as an optimal load range of the first heat source device; and a machine quantity control unit that controls a quantity of the second heat source device to operate so that the sum of a total of minimum values of the optimal load range of the first heat source device to operate and a total of minimum

Abstract: To achieve energy saving in the cooling towers as a whole in a heat source system including a plurality of cooling towers connected in parallel to a common chiller. In a heat source system, a plurality of cooling towers are connected in parallel to a common chiller. The cooling towers cool cooling water used and thereby heated in the chiller, and supplies the cooled cooling water to the chiller. A cooling tower control device for controlling the cooling towers starts all the cooling towers at the start of the heat source system.

Abstract: A control device and method for preventing the start and stop of heat source machines from being frequently repeated. The control device determining whether or not basic conditions for decreasing the number of machines are satisfied when the number of currently operating machines is increased by one is determined if a current operational status satisfies basic conditions for increasing the number of machines, and one heat source machine is started if it is determined that the basic conditions for decreasing the number of machines are not satisfied, and determining whether or not the basic conditions for increasing the number of machines are satisfied when the number of currently operating machines is decreased by one are satisfied if a current operational status satisfies the basic conditions for decreasing the number of machines, and one heat source machine is stopped if it is determined that the basic conditions for increasing the number of machines are not satisfied.

Abstract: The purpose of the present invention is to avoid frequent repetition of an increase/decrease stage caused by the inclusion, in a heat source system, of a machine the capacity of which has been degraded. A heat source system of the present invention is provided with a plurality of heat source machines. A higher-level control device (20) controls each of the heat source machines so that a heat medium delivery temperature, which is the temperature of a heat medium being supplied to an external load, will be a set temperature. The higher-level control device (20) is provided with a number-of-machines control unit (22), a degraded machine detection unit (24), and a priority ranking modification unit (25). The number-of-machines control unit (22) controls the number of heat source machines in accordance with operational priority ranking information in which each of the heat source machines and an operational priority ranking are associated together.

Abstract: A method for controlling number of pumps includes a process of increasing or decreasing the number of operating pumps based on a flow rate of a heat medium that is forcibly fed to a load (40) by a plurality of pumps connected in parallel or a heat load required by the load and a frequency command value commanded to each pump in operation among the plurality of pumps.

Abstract: Provided is a heat pump system that can appropriately manage the number of heat pumps in operation even when any of the heat pumps is defrosting, and that can always operate at a capacity that corresponds to a load. Also provided is an operation method for the heat pump system. A heat pump system (1) wherein a plurality of heat pumps (10A-10C (13A-13D)) are connected to a system load and wherein a system management unit (27) successively calculates the capacity that can be output by the heat pumps (10A-10C (13A-13D)) in operation, compares the calculated capacity value, as a threshold value, to the thermal load of the system load, and manages the number of heat pumps (10A-10C (13A-13D)) in operation.

Abstract: In the present invention pumps for transporting a heat medium to a load device are provided between the load device and heat source devices that supply the heat medium to the load device, and when the number of operating pumps changes, the number of operating heat source devices is determined on the basis of the state of the load device prior to the change in the number of operating pumps, until at least one of a prescribed condition with respect to time or a prescribed condition with respect to a value that varies due to the change in the number of operating pumps is satisfied. By means of this configuration it is possible to control the number of operating heat source devices appropriately without being affected by a transient change in a flow volume measurement value or measured load value caused by a change in the number of secondary pumps.

Abstract: It is possible to realize flow rate control regardless of the scale on a load side or a piping system and to achieve energy saving. In a host control device (20) of a heat source system, a bypass valve opening command value is determined by an opening command value determination unit (22) such that a header differential pressure matches a target differential pressure value, and a target opening value according to the header differential pressure or the behavior of the bypass valve opening is set by a target opening value setting unit (24). A heating medium flow rate set value is determined by a heating medium flow rate setting unit (23) using the target opening value set by the target opening value setting unit (24) and the opening command value determined by the opening command value determination unit (22).

Abstract: In a heat source control device, a heat source system, and a heat source control method, heat source groups, a plurality of group control units, and a number-of-units control unit are included. The group control units include a first operating-range output unit and a second operating-range output unit. When a requested load exceeds a first proper operating range, the number-of-units control unit increases the number of activated heat source groups and controls the group control units so that the number of activated heat source units is a predetermined number.

Abstract: Provided is a heat source system that includes two heat source devices connected in series to a heat medium and can be efficiently operated. A heat source system (1) reduces the temperature of chilled water that is guided from a cooling load and has a predetermined return temperature Tr, to a predetermined supply temperature Ts, and supplies the chilled water to the cooling load. The heat source system (1) includes: a second centrifugal chiller (TR2) that reduces the temperature of the chilled water from the return temperature Tr to an intermediate temperature T2; a first centrifugal chiller (TR1) that reduces the temperature of the chilled water that has been reduced to the intermediate temperature T2 by the second centrifugal chiller (TR2), to the supply temperature Ts; and a control unit (9) that variably sets the intermediate temperature T2.

Abstract: In order to achieve a reduction in energy consumption in a cooling water supply device without using a database, an equipment control device (70a) of a cooling water supply device: uses the load of a chiller, and a cooling water outlet temperature lower limit setpoint determined in accordance with the set temperature for the cooling water outlet of the chiller, to set a cooling water inlet temperature lower limit setpoint; sets, as the cooling water inlet temperature setpoint, the higher of the lower limit setpoint and the cooling water inlet temperature lower limit value as determined from the outside wet-bulb temperature; and generates a control command for a cooling tower fan and a control command for the cooling water flow volume, so as to match the cooling water inlet temperature and the cooling water outlet temperature respectively with the cooling water inlet temperature setpoint and the cooling water outlet temperature lower limit setpoint which have been set.

Abstract: To achieve energy saving in the cooling towers as a whole in a heat source system including a plurality of cooling towers connected in parallel to a common chiller. In a heat source system, a plurality of cooling towers are connected in parallel to a common chiller. The cooling towers cool cooling water used and thereby heated in the chiller, and supplies the cooled cooling water to the chiller. A cooling tower control device for controlling the cooling towers starts all the cooling towers at the start of the heat source system.

Abstract: The purpose of the present invention is to maintain a water supply temperature close to a target water supply temperature at the time of a change in the number of heat source machines operating. A heat source system of the present invention anticipates a case where a prescribed minimum flow rate is set for heat source machines that are subject to addition or removal, and calculates, as compensation temperatures, hot and cold water outlet temperatures of the heat source machines so that the water supply temperature in such a case will match a target water supply temperature, and changes the hot and cold water outlet temperature settings of the operating heat source machines to the compensation temperatures. After that, the heat source machines that are subject to addition or removal are either started up or stopped, and the set flow rate for the heat source machines that are subject to addition or removal is set to the minimum flow rate.

Abstract: To swiftly start, at the time of power recovery after a power failure, heat source machines, the number of which is equal to the number of machines before the power failure, without including an uninterruptible power supply in an apparatus for controlling the number of machines that is adapted to control the number of heat source machines. There is provided a heat source system, in which a host control device (20) includes a nonvolatile first storage unit (22) that stores the number of heat source machines in operation immediately before the power failure. When power is recovered, control on the number of heat source machines at the time of power recovery is performed in accordance with the number of heat source machines stored in the first storage unit (22).

Abstract: A technique of suppressing power consumption of a system so as to be equal to or less than contracted power when a refrigerator is used as a heat source is provided. A system control device (20) includes a power monitoring unit (23) that monitors power consumption of a heat source system and a demand restricting unit (24). The demand restricting unit (24) performs demand restriction by raising or lowering a set temperature so as to decrease power consumption of heat source equipment when the power consumption of the heat source system is greater than a first power threshold value set to a value lower than the contracted power.

Abstract: It is possible to realize flow rate control regardless of the scale on a load side or a piping system and to achieve energy saving. In a host control device (20) of a heat source system, a bypass valve opening command value is determined by an opening command value determination unit (22) such that a header differential pressure matches a target differential pressure value, and a target opening value according to the header differential pressure or the behavior of the bypass valve opening is set by a target opening value setting unit (24). A heating medium flow rate set value is determined by a heating medium flow rate setting unit (23) using the target opening value set by the target opening value setting unit (24) and the opening command value determined by the opening command value determination unit (22).

Abstract: A control device and method for preventing the start and stop of heat source machines from being frequently repeated. Whether or not basic conditions for decreasing the number of machines are satisfied when the number of currently operating machines is increased by one is determined if a current operational status satisfies basic conditions for increasing the number of machines, and one heat source machine is started if it is determined that the basic conditions for decreasing the number of machines are not satisfied. Additionally, whether or not the basic conditions for increasing the number of machines are satisfied when the number of currently operating machines is decreased by one are satisfied if a current operational status satisfies the basic conditions for decreasing the number of machines, and one heat source machine is stopped if it is determined that the basic conditions for increasing the number of machines are not satisfied.

Abstract: The need for manual adjustment of a number-of-devices controller when a system is installed or when a new heat source device is added is eliminated, and operation with a high coefficient of performance is possible even when the temperature of a heat-source medium changes. A heat source system (1) includes a plurality of heat source devices (3) that are used as hot-water heat pumps and are connected in parallel with each other, heat-source-device controllers (9) provided for the respective heat source devices (3), and a number-of-devices controller (10) that allocates a hot-water load corresponding to a demand hot-water load to each heat source device (3).