JP4594276B2 - Cold / hot water control method for cold / hot heat source machine and air conditioning system used therefor - Google Patents

Description

  The present invention relates to a cold / hot water control method for a cold / hot heat source machine and an air conditioning system used therefor.

  Conventionally, efforts have been made to improve the COP of a single cold / heat source unit. In other words, the COP of a single cold heat source unit has a higher COP of the cold heat source unit and energy saving when the production / water supply temperature is as high as possible. High energy saving. However, it is difficult to change the set temperature according to the magnitude of the load on the secondary side. Cold water remains at a low temperature setting and hot water remains at a high temperature setting (for example, cold water is 7 ° C., hot water is 42 ° C.) Thus, the manufacturing and supply temperatures are often constant at all times, which is not an energy-saving operation / control.

  As an air conditioning system using a cold / hot heat source machine (including a heat pump type refrigerator or a refrigeration machine with only a refrigeration cycle), a cooling water piping system and a cold / hot water piping system are connected to the cooling / heating heat source machine, and cooling water is connected to the cooling water piping system. Connect the pump and the cooling tower to circulate the cooling water, and connect the secondary side equipment such as the cold / hot water pump and multiple air conditioners in parallel to the cold / hot water piping system according to the load on each secondary side equipment An air conditioning system that supplies cold / hot water is generally used.

  In such an air conditioning system, in order to reduce power consumption and reduce operating costs, and to contribute to resource saving and improvement of environmental problems, it is required to improve the operating efficiency of the air conditioning system and save energy. Yes. In this case, in the cold / hot water piping system, it is necessary to reduce the power consumption of the cold / hot water pump together with the cold / hot heat source machine. The cold / hot water pump consumes less power as the flow rate and head are smaller.

  Furthermore, in order to save energy, it is necessary to reduce the power consumption of the cold / hot heat source machine. When the cold / hot heat source machine circulates cold water through the cold / hot water piping system, the power consumption is reduced by raising the water supply temperature, and when hot water is circulated, the power consumption is reduced by lowering the water supply temperature. On the other hand, if the water supply temperature of the cold water is raised (the water supply temperature is lowered), the amount of water required for the secondary equipment increases, and the power consumption of the cold / hot water pump increases.

  Therefore, in order to save energy, it is necessary to consider the power consumption of the cold / hot heat source machine after reducing the flow rate and resistance to the secondary equipment and reducing the flow rate / lift of the cold / hot water pump to reduce the power consumption. However, with regard to the pump, in the conventional control method, since the flow rate is adjusted by increasing the resistance of the flow rate adjusting valve of the secondary side equipment, this throttling operation is useless and the expected power consumption is reduced. Reduction cannot be achieved.

  Patent Document 1 describes a technical background regarding energy saving of such an air conditioning system. The cold / hot water control method for the cold / hot heat source device described in Patent Document 1 determines where the cold / hot water is required in the secondary equipment, and the flow control valve (secondary equipment) so that the water supply pressure can always be reduced. The inverter control of the secondary side cold / hot water pump is performed so that the opening degree is close to 100% (for example, 95%). However, below the minimum required flow rate of the cold / hot heat source machine, in order to ensure a constant minimum flow rate, the bypass flow rate adjustment valve is opened to reduce the required minimum supply pressure while ensuring the minimum flow rate, and the energy saving operation of the cold / hot water pump is performed. The secondary side cold / hot water supply temperature is set to the upper and lower limit temperatures (for example, 15 ° C is the upper limit for cold water and 35 ° C is the lower limit for hot water). Starts controlling the temperature of the cold / hot water so that the flow rate adjustment valve (two-way valve, etc.) opening degree becomes 95%, and the COP as the total system of the cold / hot heat source machine and the secondary cold / hot water pump at that time becomes higher In this method, the cold / hot water is changed to a variable flow rate, variable temperature, and variable lift so that the valve opening degree is 95%. The present invention realizes energy saving with a simpler structure as compared with Patent Document 1.

JP 2006-38379 A

  The present invention takes the above-mentioned prior art into consideration, and reduces the cold / hot water flow rate and the pump head while reducing the cold / hot water flow rate and the pump head while suppressing the increase in the throttle resistance of the flow adjustment valve of the cold / hot water to the secondary equipment such as an air conditioner. Cooling / heating source that can save energy with a simple structure by reducing the power consumption of the cooling / heating source by reducing the power consumption of the cooling / heating source by controlling the water supply temperature according to the opening of the flow control valve of the secondary side equipment. It aims at providing the cold / hot water control method of an apparatus, and the air conditioning system used for this.

  In order to achieve the object, in the invention of claim 1, a cold / hot water source system in which a cold / hot water piping system and a cooling water piping system are connected, and cold / hot water generated by the cold / hot water source machine are circulated in the cold / hot water piping system. An inverter controllable chilled / hot water pump, a plurality of mutually parallel secondary equipment connected to the chilled / hot water piping system, and the flow of chilled / hot water to each secondary equipment according to the load In the cold / hot water control method for a cold / hot heat source apparatus provided with a flow rate adjustment valve, the flow rate adjustment valve opening degree of each secondary side equipment is detected, and the flow rate adjustment valve opening degree of the secondary side equipment having the largest opening degree is approximately If the water supply pressure of the cold / hot water pump is reduced by inverter control so that it is fully open, and the flow adjustment valve opening of the maximum opening is still not fully open, the water supply temperature of the cold / hot heat source machine is Is characterized by raising and lowering in the case of hot water Providing hot and cold water control method that cold heat source apparatus.

  Furthermore, in the invention of claim 2, the cold / hot water source system to which the cold / hot water piping system and the cooling water piping system are connected, and inverter control for circulating the cold / hot water generated by the cold / hot water source device in the cold / hot water piping system A chilled / hot water pump, a plurality of parallel-side secondary equipment connected to the chilled / hot water piping system, and a flow rate adjusting valve that adjusts the flow of chilled / hot water to each secondary equipment according to the load. In the air conditioning system provided, the flow adjustment valve opening degree of each secondary side equipment is detected, and the flow rate adjustment valve opening degree of the secondary side equipment having the largest opening degree is almost fully opened. If the water supply pressure is reduced by inverter control and the maximum flow rate adjustment valve opening is still not fully open, a control device that raises the water supply temperature of the cold / hot heat source machine in the case of cold water and lowers it in the case of hot water. It was provided in Claim 1 characterized by the above-mentioned. Providing an air conditioning system for use in hot and cold water control method of the hot and cold heat source machine mounting.

  According to the first aspect of the present invention, the pump water supply is performed while detecting the opening degree of each of the cold / hot water flow rate adjustment valves (for example, two-way valves) of the plurality of secondary-side facilities and maintaining the required cold / hot water flow rates. By reducing the pressure, each flow control valve opening is increased, and the flow control valve opening that was the maximum opening is opened to a predetermined opening (for example, 95%) close to 100%. According to the original opening, the opening can be increased by the amount that the pump water supply pressure is reduced while maintaining the balance of the entire opening. Thereby, the cold / hot water supply pressure of the whole piping system sent from a pump can be reduced, satisfying the load calorie | heat_amount requested | required by each secondary side installation. In this case, the pump water supply amount is not reduced by restricting the flow rate adjusting valve or the like, but the pump rotation speed is controlled by inverter control to reduce the flow rate / lift, so that energy saving operation is performed.

  In addition, in order to circulate cold water through the cold / hot water piping system in order to make the flow rate adjustment valve a predetermined opening (for example, 95%) more reliably, the water supply temperature of the cold / hot heat source machine is raised, When circulating hot water in the water, lower the water supply temperature of the cold / hot heat source machine. In the case of cold water, as the cold water temperature is raised, the required amount of water in the secondary equipment gradually increases. Therefore, the flow adjustment valve opening of the secondary equipment can be increased, and the maximum heat saving can be achieved by reducing the power consumption of the heat source machine itself while satisfying the load heat quantity required by each secondary equipment. I can expect. Since this determination only needs to determine whether the supplied water is cold water or hot water, there is no need to measure other parameters such as flow rate. Energy saving can be realized with the structure.

  As a result, the system COP of the entire air conditioning system is improved, and the reduction of running costs, global environmental conservation, and reduction of CO2 emissions can be expected. At this time, if the analysis is performed using the recorded operation data, the optimum various control coefficients (internal parameters) at that time can be known. Therefore, the optimum system COP point can be determined due to aging deterioration of the equipment, pressure loss of piping, etc. Even if it deviates, it can be easily changed and the operation at which the system COP is always maximum can be continued.

  According to the invention of claim 2, since the air conditioning system is provided with the control device that realizes the cold / hot water control method of the cold / hot heat source apparatus shown in claim 1, energy saving can be realized with a simple structure.

  The present invention relates to a cold / hot water source system in which a cold / hot water piping system and a cooling water piping system are connected, and an inverter-controlled cold / hot water pump for circulating cold / hot water generated by the cold / hot water source machine in the cold / hot water piping system And a plurality of mutually parallel secondary equipment connected to the cold / hot water piping system, and a flow control valve for adjusting the flow of cold / hot water to each secondary equipment according to the load In the chilled / hot water control method, the chilled / hot water pump detects the flow rate adjustment valve opening degree of each of the secondary side equipments, and the flow rate adjustment valve opening degree of the secondary side equipment having the largest opening degree is almost fully opened. If the water supply pressure is reduced by inverter control and the maximum flow rate adjustment valve opening is still not fully open, the water supply temperature of the cold / hot heat source machine should be increased in the case of cold water and decreased in the case of hot water. Chilled / warm water control method of a chilled / heat source machine characterized Is an air conditioning system to be used in Les.

FIG. 1 is a schematic configuration diagram of an air conditioning system according to the present invention.
The air conditioning system 1 includes a cold / hot water piping system 3 and a cooling water piping system 4 connected to a cold / hot heat source device 2. The cooling water piping system 4 is provided with a cooling tower 5 and a cooling water pump 6 provided with a blower fan (not shown). The cold / hot water piping system 3 is provided with a cold / hot water pump 7 and a plurality of secondary equipment (for example, air conditioners) 8 arranged in parallel. Each secondary-side equipment 8 is provided with a flow rate adjusting valve 9 composed of, for example, a two-way valve for adjusting the cold / hot water flow rate. The water supply pressure from the cold / hot water pump 7 is measured by the pressure sensor 16.

  The cold / hot heat source device 2 is provided with temperature setting means 12 for setting the temperature of the produced cold / hot water. A temperature sensor 15 is provided in the cold / hot water pipe on the cold / hot water outlet side of the cold / hot heat source machine 2. The cold / hot water pump 7 is provided with an inverter 17 for controlling the water supply pressure.

  Each flow control valve 9 of the secondary side equipment 8, the temperature setting means 12 of the cold / hot heat source machine 2, the pressure sensor 16, the cold / hot water outlet temperature sensor 15, and the inverter 17 of the cold / hot water pump 7 are connected to the control device 19. As described later, the pressure and temperature of the cold / hot water in the cold / hot water piping system 3 are controlled.

FIG. 2 is a flowchart of the cold / hot water control method for the cold / hot heat source apparatus according to the present invention. For convenience of explanation, description will be made using reference numerals in FIG.
Step S1:
The opening degree of the flow rate adjustment valve 9 of each secondary side equipment 8 is detected.

Step S2:
It is determined whether the opening degree of the flow rate adjusting valve 9 having the maximum opening degree is 95% which is close to 100% of the maximum opening degree among the detected flow rate adjusting valves 9. If it is 95%, the process returns to step S1.

Step S3:
When there is no flow rate adjustment valve 9 with an opening degree of 95%, the water supply pressure of the cold / hot water pump 7 is reduced by controlling the inverter 17 to make the opening degree 95%. When the water supply pressure of the pump 7 decreases, each secondary side equipment 8 operates so as to increase the opening degree of the flow rate adjusting valve (two-way valve or the like) 9 in order to cope with the heat load. As a result, the flow rate adjustment valve 9 of each secondary-side facility can be adjusted so that the opening degree of the flow rate adjustment valve 9 having the maximum opening degree is 95% while maintaining the balance of the opening degree according to the respective heat loads. As the flow rate adjustment valve 9 increases, the opening degree increases. Therefore, while reducing the water supply pressure of the pump 7 and reducing power consumption, flow path resistance can be lowered | hung and a pump head can be made low, and power consumption can be reduced.

Step S4:
In a state where the pump 7 in step S3 is inverter-controlled, it is determined whether the opening degree of the flow rate adjusting valve 9 of each secondary side equipment 8 is 95%. If it is 95%, the process returns to step S1.

Step S5:
Even in step S4, when there is no flow rate adjusting valve 9 with an opening degree of 95%, it is further determined whether cold water or hot water is supplied from the cold / hot heat source unit 2 to the cold / hot water piping system 3.

Step S6:
When cold water is supplied and circulated through the cold / hot water piping system 3, the water supply temperature from the cold / hot heat source unit 2 is increased. As a result, the required amount of water in the secondary side equipment 8 gradually increases, so the opening degree of the flow rate adjusting valve 9 of the secondary side equipment 8 can be increased, and the load required by each secondary side equipment. While satisfying the amount of heat, the power consumption of the cold / hot heat source device 2 itself can be reduced to maximize energy saving.

Step S7:
When hot water is supplied and circulated through the cold / hot water piping system 3, the water supply temperature from the cold / hot heat source unit 2 is lowered. Thereby, since the request | requirement water amount in the secondary side equipment 8 increases gradually similarly to the case of step S6, the opening degree of the flow regulating valve 9 of the secondary side equipment 8 can be enlarged, While satisfying the load calorie demanded by the secondary side equipment 8, the power consumption of the cold / hot heat source machine 2 itself can be reduced and the maximum energy saving can be expected.

  In addition, the change of the water supply temperature in steps S6 and S7 is performed gradually by fixing the setting change value per unit time so as not to cause a sudden change. For example, about 0.1 ° C. per 3 minutes is preferable.

FIG. 3 is an explanatory diagram of the cold / hot water supply pressure / water supply temperature control method.
When the maximum opening degree of the flow rate adjusting valve 9 is set (A in the figure) by the control device 19 (FIG. 1) in FIG. 1, the control device 19 sets the water supply pressure and the water supply temperature.
When the water supply pressure is set (B in the figure), the inverter 17 of the pump is adjusted and controlled by the cold / hot water pump 7 to a predetermined water supply pressure. For this water supply pressure control, changes in the number of pumps, device performance deterioration, etc. act as disturbances (C in the figure), and this water supply pressure is detected by the pressure sensor 16 and feedback controlled so as to become the set water supply pressure. . Furthermore, secondary load fluctuations, equipment performance degradation, etc. act as disturbances (D in the figure) against this water supply pressure, and each secondary side equipment 8 is considered in consideration of changes in the water supply temperature described later. The maximum opening of the flow rate adjusting valve 9 (FIG. 1) is detected (E in the figure), and the water supply pressure setting is cascade controlled.

At the same time, when the water supply temperature is set (F in the figure), the water supply temperature is set by the cold / hot water temperature setting means 12 (FIG. 1) of the cold / hot heat source machine 2 (FIG. 1), and the controller inside the cold / heat source machine 12, the cooling / heating capacity is adjusted and controlled to a predetermined water supply temperature. For this water supply temperature control, cold water return temperature change, cold water flow rate change, cooling water temperature change, cooling water flow rate change, equipment performance deterioration, etc. act as disturbances (G in the figure). Feedback control is performed so that the temperature is detected by the temperature sensor 15 and reaches the set water supply temperature. Furthermore, the secondary side load fluctuation, equipment performance deterioration, etc. act as disturbances (D in the figure) against this water supply temperature, and the maximum opening degree is set by the opening degree of each flow regulating valve 9 of each secondary side equipment 8 Detection (E in the figure) and cascade control of water supply temperature setting.

  By performing the cold / hot water control method of such a cold / hot heat source machine, the system COP of the whole air conditioning system can be improved, and it can be expected that the running cost is reduced, the global environment is preserved, and the CO2 emission is reduced. At this time, if the analysis is performed using the recorded operation data, the optimum various control coefficients (internal parameters) at that time can be known. Therefore, the optimum system COP point can be determined due to aging deterioration of the equipment, pressure loss of piping, etc. Even if it deviates, it can be easily changed and the operation at which the system COP is always maximum can be continued.

  Further, according to the method of the present invention, it is not necessary to calculate the COP based on the measurement result of the flow meter or the like at regular intervals for energy saving, and the energy saving can be achieved only by the flow rate adjustment valve opening data of the secondary equipment. Therefore, a complicated control circuit is unnecessary, and a measuring device for that purpose is also unnecessary, so that the maximum energy saving can be expected with a simple structure.

  The control device 19 shown in FIG. 1 is provided with a control circuit for changing the water supply pressure and the water supply temperature of the cold / hot water pump based on the flow and description shown in FIGS.

FIG. 4 is a graph showing a cold / hot water control method of the cold / hot heat source machine in the case of circulating cold water.
The flow rate adjustment valve opening degree of the secondary side equipment is detected, and when any opening degree is 95%, in order to maintain the opening degree as it is, the water supply pressure and the water supply temperature are not changed. That is, the water supply pressure and water supply temperature (point P in the figure) at this time are used as a reference. When it is less than 95%, for example, when it is a or more and less than 95%, the water supply pressure by the pump is decreased from the water supply pressure at point P. Then, the flow rate adjustment valve opening degree is opened to be close to 95%. When the opening is not less than b and less than a, the pump is set to the minimum water supply pressure. Then, since the flow rate adjustment valve opening changes with time or according to the load on the secondary side equipment, the flow rate adjustment valve opening is detected again after a predetermined time has elapsed. When the opening degree is c or more and less than b, the water supply temperature from the cold / hot heat source machine is raised from the water supply temperature at point P with the pump at the minimum water supply pressure. Then, since the required water amount from the secondary side equipment increases, the flow rate adjustment valve opening increases. In this way, the flow rate adjustment valve opening is detected, and the flow rate adjustment valve opening is kept close to full open by setting and controlling the water supply pressure and water supply temperature according to the flow rate adjustment valve opening at that time. In addition, energy consumption can be reduced by reducing the power consumption of the pump and the cooling / heating source while satisfying the amount of load heat required by each secondary facility.

FIG. 5 is a graph showing a cold / hot water control method of the cold / hot heat source machine in the case of circulating hot water.
In the case of hot water, the setting of the water supply temperature is reversed from that in the case of cold water in FIG. That is, the control is different when the flow rate adjustment valve opening degree of the secondary side equipment is c or more and less than b. In this case, the water supply temperature from the cold / hot heat source machine is lowered with the pump at the minimum water supply pressure. That is, it is lower than the water supply temperature when the opening degree is 95%. Then, since the required water amount from the secondary side equipment increases, the flow rate adjustment valve opening increases. Other actions and effects are the same as those shown in FIG.

  INDUSTRIAL APPLICABILITY The present invention can be applied to a cold / hot water control method of a cold / hot heat source apparatus that supplies various cold / hot water and any system used therefor, and can effectively achieve energy saving by maximizing the operation efficiency of the entire system.

1 is a schematic configuration diagram of an air conditioning system according to the present invention. It is a flowchart figure of the cold / hot water control method of the cold / hot heat source machine which concerns on this invention. It is explanatory drawing of the water supply pressure and water supply temperature setting control of the cold / hot water which concerns on this invention. It is a graph which shows the cold / hot water control method of the cold / hot heat source machine in the case of circulating cold water. It is a graph which shows the cold / hot water control method of the cold / hot heat source machine in the case of circulating hot water.

Explanation of symbols

1: air conditioning system, 2: cold / hot heat source machine, 3, cold / hot water piping system, 4: cooling water piping system, 5: cooling tower, 6: cooling water pump, 7: cold / hot water pump, 8: secondary equipment, 9 : Flow control valve, 12: Temperature setting means, 15: Temperature sensor, 16: Pressure sensor, 17: Inverter, 19: Control device

Claims (2)

A cold / hot heat source machine connected to the cold / hot water piping system and the cooling water piping system;
A cold / hot water pump capable of inverter control for circulating the cold / hot water generated by the cold / hot heat source machine in the cold / hot water piping system;
A plurality of mutually parallel secondary equipment connected to the cold / hot water piping system,
In the cold / hot water control method of the cold / hot heat source machine provided with a flow rate adjustment valve that adjusts the flow of cold / hot water to each secondary side equipment according to the load,
The flow control valve opening of each secondary equipment is detected, and the water supply pressure of the cold / hot water pump is controlled by inverter control so that the flow control valve opening of the secondary equipment with the largest opening is almost fully open. If the flow adjustment valve opening of the maximum opening is not fully opened, the water supply temperature of the cold / hot heat source machine is raised in the case of cold water and lowered in the case of hot water. Cold / hot water control method. A cold / hot heat source machine connected to the cold / hot water piping system and the cooling water piping system;
A cold / hot water pump capable of inverter control for circulating the cold / hot water generated by the cold / hot heat source machine in the cold / hot water piping system;
A plurality of mutually parallel secondary equipment connected to the cold / hot water piping system,
In an air conditioning system equipped with a flow rate adjustment valve that adjusts the flow rate of cold and hot water to each secondary facility according to the load,
The flow control valve opening of each secondary equipment is detected, and the water supply pressure of the cold / hot water pump is controlled by inverter control so that the flow control valve opening of the secondary equipment with the largest opening is almost fully open. In the case where the flow rate adjustment valve opening of the maximum opening is not fully opened, a control device is provided that increases the water supply temperature of the cold / hot heat source machine in the case of cold water and decreases it in the case of hot water. The air-conditioning system used for the cold / hot water control method of the cold / hot heat source machine of Claim 1.

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