JP2007183030A - Connected type water cooler-heater, and its operating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connected type water cooler-heater, and its operating method reducing an initial cost of a whole of the connected type water cooler-heater, and capable of carrying out highly efficient (COP) operation in response to a load by composing water cooler-heaters of the connected type water cooler-heater by at least one commercial power source driven water cooler-heater, and at least one inverter driven water cooler-heater. <P>SOLUTION: The operating method is for the connected type water cooler-heater provided with the commercial power source driven water cooler-heater 11 connected to a common cold water pipe arrangement 14, a commercial power source driven slave water cooler-heater 12-1, and an inverter driven slave water cooler-heater 12-2. Each water cooler-heater carries out predetermined certain temperature control of each cold water outlet temperature. An optimum operating number is calculated at every interval certain by the number of connected water cooler-heaters, a set temperature difference of a cold water inlet and outlet, and the cold water inlet temperature. By comparison between the optimum operating number and an operating number, the operating number is maintained at the present or varied to operate the water cooler-heaters at the optimum operating number. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a connected chiller / heater including a plurality of commercial-power-driven chiller / heater units and inverter-driven chiller / heater units connected to a common chilled water pipe via a header, and an operation method thereof.

  A connected chiller / heater system, in which multiple chiller / heater units are connected to a common chilled water pipe via a header, can control the number of units in response to fluctuations in load capacity, and can be operated efficiently. It is. As the chiller / heater used in the plurality of chiller / heaters constituting the coupled chiller / heater in this way, there are a commercial power supply-driven chiller / heater and an inverter-driven chiller / heater. The commercial power supply driven chiller / heater is a chiller / heater operated by supplying electric power of frequency 60 Hz (or 50 Hz) from the commercial power supply to the drive motor, and controlling the capacity by controlling the slide valve. An inverter-driven chiller / heater is operated by supplying power from a commercial power supply to the drive motor through the inverter while changing its voltage / frequency, and capacity control is performed by voltage / frequency control by the inverter. is there.

  As shown by a curve A in FIG. 4, the commercial power supply chiller / heater has a characteristic that the efficiency (COP) is good at the maximum load (100% load) but the efficiency is poor at the partial load. On the other hand, since the inverter-driven chiller / heater is controlled by voltage / frequency control of the drive power supplied to the motor, as shown by the curve B in FIG. Although it is less efficient than (curve A), it has a characteristic that efficiency is good at partial load. In addition, the inverter-driven chiller / heater has an initial cost that is higher than that of a commercial power supply-driven chiller / heater because the inverter is provided.

If all of the multiple chiller / heater units that make up the connected chiller / heater unit are commercial power-driven chiller / heater units, the initial cost is low, but there is a problem that efficient operation is not possible in the unit operation, and the running cost is reduced accordingly. Get higher. Further, if all of the plurality of chiller / heater units are inverter-driven chiller / heater units, the number of units can be efficiently operated and the running cost can be reduced, but the initial cost is increased.
JP 2004-144457 A

  The present invention has been made in view of the above-described points, and the chiller / heater of the connected chiller / heater is composed of at least one commercial power supply-driven chiller / heater and at least one inverter-driven chiller / warmer. An object of the present invention is to provide a connected chiller / heater that can be operated at high efficiency (COP) according to the load, and an operation method thereof, while reducing the initial cost of the chiller / cooler.

  In order to solve the above-mentioned problems, the present invention according to claim 1 includes at least one commercial-power-driven chiller / heater connected to a common chilled water pipe and at least one inverter-driven chiller / heater. A method of operating a connected chiller / heater, wherein each chiller / heater controls the temperature of each chilled water outlet at a predetermined constant temperature during refrigeration operation, the number of chilled water heaters connected, the temperature difference between the chilled water inlet / outlet, Calculate the optimal number of units to be operated at regular intervals based on the inlet temperature, and maintain or increase / decrease the number of units in operation by comparing the optimal number of units with the number of units operated, and operate the chiller / heater with the optimal number of units to be operated. Features.

  In addition, the cold / hot water machine here does not indicate only a device that can be used for both freezing and hot water, but also includes a simple refrigerator that has only a function of taking out cold water and is not intended to take out hot water.

  The invention according to claim 2 is the operation method of the connected chiller / heater according to claim 1, wherein the inverter-driven chiller / heater is preferentially operated when the number of the chiller / heater increased. When the number of operating units decreases, the commercial power supply chilled water heater is stopped preferentially, and the chilled water outlet temperature setting temperature of the chilled water heater can be cascade-controlled. Compared to the machine, the cold water set temperature is lowered by a certain value or a load signal is given to the compressor to increase the load.

  The invention described in claim 3 is a connected chiller / heater in which a plurality of chiller / heaters are connected to a common chilled water pipe, and the plurality of chiller / heaters are connected to at least one commercial power source driven chiller / heater. A water machine and at least one inverter-driven chiller / heater are used, and each chiller / heater controls each chilled water outlet temperature to a predetermined constant temperature during refrigeration operation, and sets the number of connected chiller / hot water machines and the chilled water inlet / outlet. Calculate the optimum number of units to be operated at regular intervals based on the temperature difference and the chilled water inlet temperature, and maintain or increase / decrease the number of units in operation by comparing the optimum unit with the number of units in operation. An operation control means for operating is provided.

  According to a fourth aspect of the present invention, in the connected chiller / heater according to the third aspect, the operation control means preferentially operates the inverter-driven chiller / heater when the number of chilled / hot water heaters is increased, When the number of operating units decreases, the commercial power supply chilled water heater is stopped preferentially, and the chilled water outlet temperature setting temperature of the plurality of chilled water heaters can be cascade-controlled. Compared to the drive chiller / heater, the chilled water set temperature is lowered by a certain value or a load signal is given to the compressor to increase the load.

  According to the first aspect of the present invention, during the refrigeration operation, each chiller / heater controls the chilled water outlet temperature at a predetermined constant temperature, the number of chilled water heaters connected, the chilled water inlet / outlet set temperature difference, and the chilled water inlet temperature. To calculate the optimal number of units to be operated at regular intervals, and maintain or increase or decrease the number of units in operation by comparing the optimal number of units with the number of units in operation and operate the chiller / heater with the optimal number of units. Efficient operation over partial loads is possible, reducing running costs and reducing the initial cost of all connected chilled water heaters compared to when all units are composed of inverter-driven chilled water heaters Can provide driving methods.

  According to the second aspect of the present invention, when the number of operating chilled water heaters increases, the inverter driven chilled water heater is prioritized and when the number of operating chillers decreases, the commercial power source driven chilled water heater is prioritized and stopped. The chilled water outlet temperature setting temperature of the chilled water heater can be cascade controlled, and the commercial power supply chilled water heater can lower the chilled water set temperature by a certain value or give a load signal to the compressor compared to the inverter driven chiller water heater. Since a large load is applied, it is possible to reduce the initial cost and improve the efficiency of the entire connected chiller / heater.

  According to the third aspect of the present invention, the plurality of chiller / heaters are at least one commercial-power-driven chiller / heater and at least one inverter-driven chiller / heater. Occasionally, each chilled water outlet temperature is controlled to a predetermined constant temperature, and the optimal number of operating units is calculated every fixed time according to the number of connected chilled water heaters, the temperature difference between the chilled water inlet and outlet, and the chilled water inlet temperature. Compared to the above, the operation control means to maintain the number of operating units at the current state or increase / decrease and operate the chiller / heater with the optimal number of operating units is provided, enabling efficient operation from the maximum load to partial load and running cost In addition, it is possible to provide a connected chiller / heater that reduces the initial cost of the entire connected chiller / heater compared to a case where all the units are configured by inverter-driven chillers / heaters.

  According to a fourth aspect of the present invention, the operation control means preferentially operates the inverter-driven chiller / heater when the number of chilled water heaters is increased, and the commercial power supply chiller / heater is decreased when the number of operated chillers is decreased. In addition to stopping with priority, it enables cascade control of the chilled water outlet temperature setting temperature of multiple chilled water heaters. Does the commercial power supply chilled water heater reduce the chilled water set temperature by a certain value compared to the inverter driven chiller water heater? Alternatively, since the load signal is given to the compressor to increase the load, it is possible to reduce the initial cost of the connected chiller / heater and improve the efficiency.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the following description mainly demonstrates the form of the freezing operation which uses a cold / hot water machine as a refrigerator. FIG. 1 is a diagram showing a configuration example of a connected chiller / heater according to the present invention. As shown in FIG. 1, this connected chiller / heater includes one master chiller / heater 11 and two slave chillers 12-1 and 12-2. The parent machine cold / hot water machine 11, the child machine cold / hot water machine 12-1, and the child machine cold / hot water machine 12-2 are connected to the cold water pipe 14 by the reverse ring water method via the header 13. The cold water W is configured to flow evenly from the main device cold / hot water machine 11, the child machine cold / hot water machine 12-1, and the child machine cold / hot water machine 12-2.

  Here, the parent / cooling / hot water machine 11 and the child's cooling / heating machine 12-1 are commercial power source driven cold / hot water machines that are driven by directly supplying commercial power from a commercial power source (without frequency conversion). The chiller / heater 12-2 is an inverter-driven chiller / heater that drives the electric power from a commercial power source by converting the voltage and frequency through an inverter and supplying the converted electric power to the drive motor. In addition, this connected chiller / heater can connect up to four slave chillers 12.

  A chilled water inlet temperature sensor 16 is attached to the chilled water inlet pipe 15 of the parent chiller / hot water machine 11, and each of the parent chiller / hot water machine 11, the child chiller / hot water machine 12-1, and the child machine chiller / heater 12-2. A cold water outlet temperature sensor 18 is attached to the cold water outlet pipe 17. An operation panel 19 is provided in each of the parent machine cold / hot water machine 11, the child machine cold / hot water machine 12-1, and the child machine cold / hot water machine 12-2, and a CPU (not shown) is incorporated therein. Each operation panel 19 is connected by an inter-module communication wiring 20, and the inlet temperature is set by cold water from the parent machine cooling / warming water machine 11 to the child machine cooling / warming water machines 12-1, 12-2, Data transmission is performed from 12-2 to the main unit cold / hot water machine 11. In addition, the parent / cooling / hot water machine 11 is remotely controlled via a remote signal line 23.

  The control panel 19 of the master chiller / heater 11 has a chilled water inlet temperature detected by the chilled water inlet temperature sensor 16, a chilled water outlet temperature detected by the junction chilled water outlet temperature sensor 22, and a remote control signal S from the remote signal line 23. Is entered. The operation panel 19 of each chiller / heater is provided with a temperature controller 24 so that the output of the chilled water outlet temperature sensor 18 is input. Further, a temperature setting control unit 25 is provided in the parent / cooling / hot water machine 11 so as to control the set temperature of each cooling / heating machine.

  Each of the main unit cold / hot water machine 11, the sub-unit cold / hot water machine 12-1, and the sub-unit cold / hot water machine 12-2 changes the suction air volume of the compressor to control the cold water outlet temperature to a constant value. Further, in the operation panel 19 of the main unit chiller / heater 11, in order to control the average temperature of each chiller / heater outlet temperature or the temperature of the junction, the chilled water or outlet set temperature of each chiller / heater is cascade controlled. Yes. Reference numeral 21 denotes a chilled water pump, and the chilled water W from the chilled water pump 21 passes through the chilled water pipe 14, the header 13, and the chilled water inlet pipes 15, 15, and 15, and the master chiller / heater 11 and the slave chiller / heater 12-1. And the cold water of each evaporator 33 are discharged through the cold water outlet pipes 17, 17, 17 and merge with the cold water pipe 14 on the outlet side.

  FIG. 2 is a diagram illustrating a configuration example of a parent machine cooling / heating machine 11 and a child machine cooling / heating machine 12-1, which are commercial power supply driven cooling / heating machines. The commercial power supply driven chiller / heater includes a compressor 30, a condenser 31, an expansion valve 32, and an evaporator 33, and these devices are connected by a refrigerant pipe 34. Refrigerant vapor evaporated in the evaporator 33 is sucked into the compressor 30 and compressed into high-temperature and high-pressure refrigerant vapor, cooled in the condenser 31 with cooling water passing through the cooling water pipe 35, and becomes refrigerant condensed liquid. The refrigerant condensate is depressurized to a low pressure and a low temperature by the expansion valve 32, enters the evaporator 33 and evaporates, and cools the cold water passing through the cold water inlet pipe 15.

  A commercial power supply (AC) is supplied to the drive motor 39 of the compressor 30 via the wiring breaker 37 and the star-Δ contactor 38, and the compressor rotor 44 is operated by rotating the compressor rotor 44 at about 3600 rpm at 60 Hz. ing. The cold water outlet temperature detected by the cold water outlet temperature sensor 18 provided at the outlet of the cold water outlet pipe 17 is sent to the temperature controller 24. The temperature regulator 24 opens and closes the capacity electromagnetic valve 41, and the piston 42 is operated to slide. The valve 43 is moved to control the suction air volume continuously and continuously so that the cold water outlet temperature is constant.

  FIG. 3 is a diagram showing a configuration example of a slave unit chiller / heater 12-2 that is an inverter-driven chiller / heater. The inverter-driven chiller / heater includes a compressor 30, a condenser 31, an expansion valve 32, and an evaporator 33, and these devices are connected by a refrigerant pipe 34. Refrigerant vapor evaporated in the evaporator 33 is sucked into the compressor 30 and compressed into high-temperature and high-pressure refrigerant vapor, cooled in the condenser 31 with cooling water passing through the cooling water pipe 35, and becomes refrigerant condensed liquid. The refrigerant condensate is depressurized to a low pressure and a low temperature by the expansion valve 32, enters the evaporator 33 and evaporates, and cools the chilled water passing through the chilled water inlet pipe 15 in the same manner as the commercial power supply driven chiller / heater shown in FIG. is there.

  The commercial power supply (AC) is supplied to the inverter 46 through the wiring breaker 37, and is supplied to the drive motor 39 of the compressor 30 by changing the voltage and frequency. The cold water outlet temperature detected by the cold water outlet temperature sensor 18 provided at the outlet of the cold water outlet pipe 17 is sent to the temperature controller 24, and the inverter 46 is controlled by the temperature controller 24 to increase or decrease the rotational speed of the drive motor 39. Thus, the cold water outlet temperature is controlled to be constant by changing the amount of air sucked into the compressor 30.

  FIG. 4 shows the partial load characteristics of the commercial power supply driven chiller / heater that is the slide valve control and the inverter driven chiller / heater that is the rotational speed control. In FIG. 4, a curve A shows a partial load characteristic of a commercial power supply driven chiller / heater, and a curve B shows a partial load characteristic of an inverter driven chiller / heater. As shown in the figure, in the vicinity of the maximum load (100%), in the inverter-driven chiller / heater, the efficiency of the inverter 46 is reduced by 2-4% compared to the commercial power-driven chiller / heater, but the partial load is reduced. Then, the inverter-driven chiller / heater can operate more efficiently.

As described above, the connected cold / hot water machine 11 is a combination of the parent / cooling / hot water machine 11 and the child machine / cooling / heating machine 12-1, which are commercial power supply-driven cooling / heating machines, and the child machine cooling / heating machine 12-2, which is an inverter-driven cooling / heating machine. In a water machine, high efficiency operation is possible by controlling the number of commercial power source driven chiller / heater units and inverter-driven chiller / heater units according to the load. Here, the number N of chilled / hot water units set in the main unit chiller / hot water device 11, the chilled water inlet / outlet set temperature difference is DT (when 100% load is set), the chilled water outlet set temperature Sv, and the actual load. Obtain the optimum number of units (required number of units) r from the following formula using the cold water inlet temperature Ti,
r = {N × (Ti−Sv)} / DT
From the difference from the number of operating units R, maintaining the number of operating units at the current state or increasing / decreasing the number of units at a certain time and operating with the optimal number of units enables high-efficiency operation of the entire connected chiller / heater.

  FIG. 5 is a diagram showing a unit operation flow during cooling in the connected chiller / heater. It is determined whether or not [r + 1 + α] <R continuously for a predetermined time (3 minutes in the present embodiment) (step ST1). If YES, the operation of the commercial power supply chiller / heater is reduced by one, that is, The commercial power supply chiller / heater is preferentially stopped (step ST2), and if NO, it is determined whether or not R <[r−α] continuously for a predetermined time (in this embodiment, 3 minutes) (step ST3). If YES, the number of inverter-driven chiller / heaters is increased by one, that is, the inverter-driven chiller / heater is operated with priority (step ST4). If NO, the process returns to step ST1 and the process is repeated.

  FIG. 6 is a diagram showing a calculation result of the number of cooling units during cooling. In FIG. 6, the horizontal axis indicates the chilled water temperature [° C.] and the required number r of chilled water heaters, and the ordinate indicates the number R of operating water. Here, a case where the cold water outlet temperature of the cold / hot water machine is maintained and controlled at a constant temperature of 7 ° C. is shown. As shown in the figure, in the operation of one or two chiller / heaters, when the chilled water inlet temperature decreases by α, one chiller / heater is stopped, and when α rises, one additional chiller / heater is operated.

  By calculating the optimum number of chilled water heaters at regular intervals and maintaining the current number of chilled water heaters or increasing or decreasing them one by one, changes in the chilled water outlet temperature at the merging section during unit operation can be reduced. Since the chilled water W can be supplied at a stable temperature and at the same time the chiller / heater is not started simultaneously, the influence of the starting current on the power supply system can be reduced. Furthermore, when the cold water outlet temperature falls by 2 ° C. below a predetermined value, it is automatically stopped to prevent the outlet temperature of the cold / hot water from dropping too much.

  FIG. 7 is a diagram showing a partial load characteristic during a connected operation of a connected chiller / heater equipped with a plurality of chiller / heaters. In FIG. 7, a curve A indicates two commercial power source driven chiller / heaters (master chiller / heater 11 and slave chiller / heater 12-1) and one inverter-driven chiller / heater (child slave) according to the present embodiment. The partial load characteristics of a connected chiller / heater consisting of a chiller / heater 12-2), curve B shows the partial load characteristics of all three chiller / heaters, and curve C shows the chill / cooler All water machines show the partial load characteristics of commercial power supply chilled / hot water machines.

  As shown by the curve A, in the connected chiller / heater according to the present embodiment, the commercial power supply chiller / warm water machine (the master chiller / heater 11 and the slave chiller / heater 12-1) sets the chilled water outlet temperature to (1). Reduce the temperature by 5 ° C to 5.5 ° C so that the load is applied, and the inverter-driven chiller / heater 12-2 has a higher chilled water outlet set temperature than the commercial power-driven chiller / heater. By operating at a partial load, a high COP at a large load of the commercial power supply driven chiller / heater and a high COP at a partial load of the inverter driven chiller / heater can be used effectively. The COP can be increased while keeping the initial cost increase to a minimum value compared to the driving chiller / heater. In addition, even when the entire curve B is near 100% and near the minimum load even when compared to the inverter-driven chiller / heater, high-efficiency operation can be performed, and the initial cost can be kept low.

  Commercial power-driven chiller / heater (master chiller / heater 11 and slave chiller / heater 12-1) is operated by lowering the chilled water outlet temperature set temperature or by applying a load by giving a load signal, and the remaining load is invertered By performing partial load operation with the driving chiller / heater (here, the slave chiller / heater 12-2), it is possible to reduce the initial cost of the coupled chiller / heater as a whole and improve the efficiency.

  In the above embodiment, the mode of the refrigeration operation has been mainly described, but the details of the piping and the like are illustrated even when operated as a hot water machine that takes out the fluid at the outlet of the condenser as hot water by switching the flow path of cold water or cooling water. Is omitted, but can be controlled similarly. Similar to that shown in FIG. 6, the number control based on the number of connections N, the inlet / outlet set temperature difference DT, the outlet set temperature Sv, and the inlet temperature Ti (the temperature in this case is the hot water temperature) is possible. In addition, commercial power supply chilled water heaters are operated by raising the hot water outlet temperature set temperature or by applying a load by giving a load signal, and by operating the remaining load partly with an inverter driven chiller water heater. The initial cost of the entire water machine can be reduced and the efficiency can be improved as in the case of operating the refrigerator.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible.

It is a figure which shows the structural example of the connection type cold / hot water machine which concerns on this invention. It is a figure which shows the structural example of the commercial power source drive cold / hot water machine used for the connection type cold / hot water machine which concerns on this invention. It is a figure which shows the structural example of the inverter drive cold / hot water machine used for the connection type cold / hot water machine which concerns on this invention. The partial load characteristics of commercial power supply driven chilled water heaters and inverter driven chilled water heaters are shown. It is a figure which shows the number operation flow at the time of cooling of the connection type cold / hot water machine which concerns on this invention. It is a figure which shows the unit operation calculation result at the time of cooling of the connection type | mold cold / hot water machine which concerns on this invention. It is a figure which shows the partial load characteristic at the time of the connection driving | operation of a connection type | mold cold / hot water machine.

Explanation of symbols

11 Chiller / Hot Water Machine 12 Child Machine Chiller / Heater 13 Header 14 Chilled Water Pipe 15 Chilled Water Inlet Pipe 16 Chilled Water Inlet Temperature Sensor 17 Chilled Water Outlet Pipe 18 Chilled Water Outlet Temperature Sensor 19 Operation Panel 20 Module Communication Wiring 21 Chilled Water Pump 22 Merged Port Chilled Water Outlet temperature sensor 23 Remote signal line 24 Temperature controller 25 Temperature setting control unit 30 Compressor 31 Condenser 32 Expansion valve 33 Evaporator 34 Refrigerant piping 35 Cooling water piping 38 Star-Δ contactor 39 Drive motor 41 Capacitance solenoid valve 42 Piston 43 Slide valve 44 Compressor rotor 46 Inverter

Claims (4)

An operation method of a connected chiller / heater equipped with at least one commercial power-driven chiller / heater connected to a common chilled water pipe and at least one inverter-driven chiller / heater,
Each chilled water heater controls the temperature of each chilled water outlet at a predetermined constant temperature during refrigeration operation, and calculates the optimal number of units to be operated at fixed time intervals based on the number of connected chilled water heaters, chilled water inlet / outlet set temperature difference, and chilled water inlet temperature. The operation method of the connected chiller-heater is characterized in that the chilled water heater is operated with the optimum operation number by maintaining or increasing or decreasing the number of the operation number by comparing the optimum operation number and the operation number. It is a driving | running method of the connection type cold / hot water machine of Claim 1, Comprising:
When the number of operating chilled water heaters is increased, the inverter driven chilled water heater is prioritized, and when the operating number is decreased, the commercial power driven chilled water heater is prioritized and the chilled water outlet of the chilled water heater is Enables cascade control of temperature setting temperature,
Compared with the inverter-driven chiller / heater, the commercial power-driven chiller / heater is configured to reduce the set temperature of the chilled water by a certain value or to provide a load signal to the compressor to increase the load. How to drive a water machine. It is a connected chiller / heater with multiple chillers connected to a common chilled water pipe,
The plurality of chiller / heaters are at least one commercial power supply chiller / heater and at least one inverter-driven chiller / heater,
Each chiller / heater controls the chilled water outlet temperature to a predetermined constant temperature during refrigeration operation, and calculates the optimum number of units to be operated at fixed time intervals based on the number of connected chillers, the chilled water inlet / outlet set temperature difference, and the chilled water inlet temperature. In addition, it is possible to maintain or increase or decrease the number of operating units to the current state by comparing the number of operating units with the number of operating units, and to provide an operation control means for operating the chiller / heater with the optimal number of operating units. Water machine. In the connection type cold / hot water machine of Claim 3,
The operation control means preferentially operates the inverter-driven chiller / heater when the number of chilled water heaters increases, and prioritizes and stops the commercial power-driven chiller / heater when the number of operated units decreases. Cascade control of the chilled water outlet temperature setting temperature of the chiller / warm water heater is performed, and the commercial power source driven chiller / heater lowers the chilled water set temperature by a constant value or a load signal to the compressor as compared with the inverter driven chiller / warm water heater. A connected chiller / heater characterized by having a function to apply a large amount of load.

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