JPH1096544A - Controller for cold water temperature and cold water amount in heat storage water tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the scale of equipment and expense for operation power by keeping unchanged at all time a difference between water temperatures in a low temperature tank and in a high temperature tank of a heat storage water tank, and ensuring the operation of high temperature tank cold water cooling means with a high load ratio per unit time. SOLUTION: An apparatus for storing and supplying a cold heat source of air conditioning is adapted such that water in a high temperature tank 2 of a heat storage water tank 1 equipped with the high temperature tank 2, a low temperature tank 3, and a water storage tank in which high temperature water and low temperature water are stored is cooled with high temperature tank cold water cooling means 5 and is transferred into the low temperature tank 3, and the cold water in the low temperature tank 3 is supplied to a load device 6 with cold water supply means 8 and the water heat exchanged in the load device 6 is returned to the high temperature tank 2. In the apparatus, there are provided means 7 for keeping the cold water outlet temperature of the load device 6 unchanged at all times by detecting load capacitance of the load device 6 based upon a change in outlet water temperature of the load device 6 and converting it to the amount of cold water, and means 9 for change the amount of supply of cold water of the cold water supply means 8 by detecting a change in the amount of cold water of the load device 6 and instructing the cold water supply means 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for controlling the temperature and amount of cold water in a heat storage water tank in a device for storing and supplying an air-conditioned cold heat source.

[0002]

2. Description of the Related Art Conventionally, as shown in the schematic diagram of FIG. 3, as a device for storing and supplying an air-conditioned cold heat source, a heat storage water tank 20 containing cold water at 7 to 8 ° C. A load device 23 for supplying and exchanging heat, a return-side heat storage water tank 21 in which high-temperature water is returned from the load device 23 and stores water at 10 to 16 ° C., and a heat storage water tank 20 bypassing the load and the like device 23. A bypass flow passage 24 communicating with the return-side heat storage water tank 21;
And a refrigerator 25 that cools the water to 7 to 8 ° C. and supplies the water to the heat storage water tank 20.

In the conventional apparatus, the amount of water of the chilled water supply means for supplying the chilled water to the load device 23 is always supplied with the maximum amount of water per unit time so as to have a capacity corresponding to the maximum load. A large amount of water into the bypass channel 24
In the return side heat storage water tank 21, the water whose temperature has risen by bypassing the load device 23 is bypassed and mixed in the return side heat storage water tank 21, and stored in the return side heat storage water tank 21 at a lower temperature than at the time of maximum load.

Therefore, the water temperature of the return-side heat storage water tank 21 changes due to a change in load. When the load is small, the water temperature of the return-side heat storage water tank 21 decreases, and the low-temperature heat storage water tank 20 and the high-temperature return-side heat storage water tank 21 And the difference in water temperature decreases.

When the difference in water temperature between the low-temperature heat storage water tank 20 and the high-temperature return-side heat storage water tank 21 is reduced, the amount of heat storage that can be utilized by the heat storage water tank becomes equal to the retained water amount and the low-temperature heat storage water tank 20.
And the water temperature of the high-temperature return-side heat storage water tank 21, the amount of heat that can be used is greatly reduced from the amount of heat consumed by the load.

Therefore, when the heat storage amount of the heat storage water tank is decreasing, the cooling of the load device 23 cannot be satisfied unless the heat storage amount is equal to or more than the required heat amount per unit time of the load.

For this reason, the water in the high-temperature storage water tank 21 is cooled by the refrigerator 25 to a water temperature of 7 to 8 ° C. in the low-temperature storage water tank 20 and transferred to the low-temperature storage water tank 20 for storage.

As a result, the cooling capacity of the refrigerator 25 during one cycle is equal to or greater than the load capacity, and when the cooling capacity per unit time of the refrigerator 25 is apportioned over one cycle, the cooling capacity per unit time is obtained. Since the maximum load capacity is larger, the amount of water of the chilled water supply means to the load device 23 is larger than the amount of water of the refrigerator 25.

The refrigerator 25 and the load device 2 per unit time
If the product of the difference in the amount of water of the cold water supply means and the operation time exceeds the amount of water held in the heat storage water tank, the water temperature of the low-temperature heat storage water tank 20 rises, and the low water temperature required by the load device 23 cannot be supplied.

To avoid this, a method is adopted in which the cooling capacity of the refrigerator 25 is made larger than the capacity apportioned in one cycle time so that the water temperature of the low-temperature heat storage water tank 20 can be satisfied.

[0011]

As described above, conventionally, when the difference in water temperature between the high-temperature return-side heat storage water tank and the low-temperature heat storage water tank falls below a specified value, the load of the high-temperature tank cold water cooling means (refrigerator) is reduced. When the rate decreases and the cooling capacity of the load within one cycle of the half surface remains unchanged, the high-temperature tank cold water cooling means (refrigerator)
It becomes necessary to replenish the reduced load factor at another time.

This replenishment requires an increase in the capacity of the high-temperature tank cold water cooling means (refrigerator) and an increase in the amount of water stored in the heat storage water tank, and also needs to be compatible with a large number of independent load devices. As a result, there is a problem that the equipment cost and the operating power cost increase, and it has been a problem to improve them.

An object of the present invention is to keep the difference between the water temperature of the low-temperature tank and the high-temperature tank of the heat storage water tank constant, to enable the high-temperature tank cooling water cooling means to always operate at a high load rate per unit time, and to reduce the equipment scale. Another object of the present invention is to provide a control device for controlling the cold water temperature and the cold water amount of the heat storage water tank which can reduce the operating power cost.

[0014]

According to the present invention, there is provided a heat storage water tank having a high-temperature tank, a low-temperature tank, and a water storage tank in which high-temperature water and low-temperature water are stored. High-temperature tank cold-water cooling means for cooling water in the high-temperature tank and transferring it to the low-temperature tank, cold-water supply means for supplying cold water from the low-temperature tank to a load device, and returning the water heat-exchanged by the load device to the high-temperature tank. In a device for storing and supplying an air-conditioned cold heat source that flows, means for detecting a load capacity of the load device, converting the capacity into a chilled water amount, and constantly maintaining a chilled water outlet temperature of the load device constant. Means for detecting a change in the amount of chilled water of the load device and giving an instruction to the chilled water supply means to change the chilled water supply amount of the chilled water supply means.

[0015]

Embodiments of the present invention will be described below. In FIG. 1, reference numeral 1 denotes a heat storage water tank. The heat storage water tank 1 includes a high temperature tank 2, a low temperature tank 3, and a water storage tank 4 in which high temperature water and low temperature water are stored. The water storage tank 4 is a high-temperature tank 2
The high-temperature water overflowing from the reservoir accumulates in the upper layer, and the low-temperature water in the low-temperature tank 3 flows in from the lower part and is stored in the lower layer.

The water in the high-temperature tank 2 is cooled by a high-temperature tank cold water cooling means 5.
And transferred to the low-temperature tank 3. The cold water in the low-temperature tank 3 is supplied to the load device 6 by the cold water supply means 8, and the water exchanged by the load device 6 is returned to the high-temperature tank 2. It has become.

This is used, for example, in an automobile manufacturing plant or other devices for storing and supplying air-conditioned cold heat.

According to the present invention, in the above configuration, means 7 for detecting the load capacity of the load device 6, converting the capacity into a chilled water amount, and keeping the chilled water outlet temperature of the load device 6 always constant.
And means 9 for detecting a change in the amount of chilled water of the load device 6 and giving an instruction to the chilled water supply means 8 to change the chilled water supply amount of the chilled water supply means 8. The load devices 6 are independent of each other and are individually controlled.

A specific embodiment of the above configuration will be described with reference to FIG. The high-temperature tank cold water cooling means 5 is suitably, for example, an absorption refrigerator. The high-temperature water pumped up by the pump 10 from the high-temperature tank 2 of the heat storage water tank 1 is supplied to the high-temperature tank cold water cooling means 5 through a pipe 12a.
And the cold water cooled by the high-temperature tank cold water cooling means 5 is transferred to the low-temperature tank 3 of the heat storage water tank 1 via the pipe line 12b.

The load device 6 has a chilled water coil and a blower, and the air flows between the chilled water coils to lower the temperature of the wind and supply it to a place requiring cold air.

The means 7 for detecting the load capacity of the load device 6 and converting the capacity to a chilled water amount to keep the chilled water outlet temperature of the load device 6 constant at all times is a chilled water supply line on the inlet side of the load device 6. 13 is provided with a valve capable of automatically adjusting the amount of water, for example, an electric valve 7c for adjusting the amount of water, and the high-temperature water flowing back through the high-temperature water returning flow pipe 15 A water temperature sensor 7a (temperature measuring resistor) for detecting a temperature is arranged, and a temperature signal detected by the water temperature sensor 7a is converted into an electric signal by an instruction controller 7b (electrical converter), and the water amount adjusting electric valve 7c is operated. The configuration is such that it is controlled.

The chilled water supply means 8 pumps chilled water from the low temperature tank 3 of the heat storage water tank 1 and sends it to the chilled water supply pipe 13.
It is.

A means 9 for detecting a change in the amount of chilled water of the plurality of load devices 6 and giving an instruction to the chilled water supply means 8 to change the chilled water supply amount of the chilled water supply means 8 is provided downstream of the water amount adjusting electric valve 7c. Pressure sensor 9a
The signal detected by the pressure sensor 9a is controlled via the inverter 9b to control the rotation speed of the pump 11, and the excess flow of the discharge flow of the pump 11 is returned to the low temperature tank 3 of the heat storage water tank 1 by the return pipe 14. This is the configuration.

Since the present invention is configured as described above, the high-temperature tank 2 of the heat storage water tank 1 receives the high-temperature water, which has been heat-exchanged by the load device 6 and has been heated to an arbitrary temperature of 10 to 16 ° C. The high-temperature water in the tank 2 is cooled to a low-temperature water having an arbitrary temperature of 7 to 8 ° C. by the high-temperature tank cold water cooling means 5 by the pump 10 and transferred to the low-temperature tank 3 of the heat storage water tank 1.

The cold water in the low temperature tank 3 of the heat storage water tank 1 is supplied to the pump 11
And is supplied to the load device 6 through the cold water supply line 13.

In order to keep the water temperature on the inlet side of the load device 6 constant and also keep the water temperature on the outlet side constant, a change in the amount of heat of the load device 6 is coped with by variably adjusting the amount of water.

That is, when the amount of heat of the load device 6 increases and the temperature of the high-temperature water flowing through the high-temperature water return pipe 15 on the outlet side of the load device 6 increases, the water temperature sensor 7a senses this, and the load device 6 A command to increase the amount of chilled water is issued to the water amount adjusting electric valve 7c on the inlet side, and the amount of chilled water supplied to the load device 6 is increased to suppress a rise in water temperature on the outlet side of the load device 6 and to reduce the temperature of the outlet side of the load device 6. Control the water temperature constant.

Conversely, when the heat amount of the load device 6 decreases, the water temperature sensor 7a senses the decrease and issues a command to reduce the amount of chilled water to the water amount adjustment motor-operated valve 7c on the inlet side of the load device 6. By reducing the amount of cold water supplied to the load 6, a drop in the water temperature at the outlet of the load device 6 is suppressed, and the outlet water temperature of the load device 6 is controlled to be constant.

Further, a change in the amount of chilled water supplied to the load device 6 is detected, and the amount of chilled water supplied is controlled to an appropriate amount. This is because the pressure sensor 9a detects the pressure fluctuation of the chilled water passing through the chilled water supply line 13, controls the rotation speed of the pump 11 via the inverter 9b, and determines the surplus flow rate of the discharge flow rate of the pump 11 by the return pipe. Then, the amount of cold water supplied to the load device 6 is controlled to an appropriate amount. When the number of rotations has to be reduced below the lower limit of the normal operation of the pump 11 when the load capacity is small and the pump 11 has a lower capacity, the reflux pipe 1
At 4, the surplus flow rate is returned to the low temperature tank 3.

By the above-described respective controls, the high-temperature tank 2 of the heat storage water tank 1
Is always returned at a constant water temperature (any temperature of 10 to 16 ° C.) and is stored at a constant water temperature (any temperature of 10 to 16 ° C.). The inlet water temperature of the refrigerator is always the constant water temperature (10 to 16 ° C).
Can be operated at the upper limit of the temperature of the high-temperature tank, and the capacity of the high-temperature tank cold-water cooling means 5 can be utilized to the maximum without increasing the capacity of the high-temperature tank cold-water cooling means 5 or increasing the amount of water retained in the heat storage water tank.

Further, since the amount of water supplied to the chilled water supply means 8, ie, the pump 11, is controlled to an appropriate amount according to the required amount of water, the operating power of the pump 11 can be reduced when the amount of supplied water is small.

[0032]

As described above, according to the present invention, by keeping the inlet water temperature of the high-temperature tank cold water cooling means constant, the capacity of the high-temperature tank cold water cooling means and the capacity of the heat storage water tank can be increased without increasing the water capacity. In order to reduce equipment costs and to change the amount of chilled water supplied by the chilled water supply means to an appropriate amount in response to the change in the capacity of the load device,
This has the advantage that the operating power cost (running cost) of the chilled water supply means can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of the present invention.

FIG. 2 is a specific configuration diagram of each means of the present invention.

FIG. 3 is a schematic configuration diagram of a conventional apparatus.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 heat storage water tank 2 high temperature tank 3 low temperature tank 4 water storage tank 5 high temperature tank cold water cooling means 6 load device 7 means for detecting load capacity and converting the capacity into cold water quantity to keep constant cold water outlet temperature of load device 7a Water temperature sensor 7b Indicator controller (electrical converter) 7c Electric motor for adjusting water flow 8 Cooling water supply means 9 Means for detecting a change in the amount of chilled water in the load device and giving an instruction to the chilled water supply means to change the chilled water supply amount of the chilled water supply means 9a Pressure sensor 9b Inverter 10 Pump 11 Pump 12a Pipe 12b Pipe 13 Cold water supply pipe 14 Reflux pipe

Claims (1)

[Claims] 1. A heat storage water tank comprising a high temperature tank, a low temperature tank, and a water storage tank for storing high temperature water and low temperature water, and a high temperature tank cold water cooling means for cooling water in the high temperature tank and transferring the water to the low temperature tank. When,
A cold water supply means for supplying cold water in the low-temperature tank to a load device; and an apparatus for storing and supplying an air-conditioned cold heat source configured to return water subjected to heat exchange in the load device to the high-temperature tank, wherein the load is Means for detecting the load capacity of the device, converting the capacity to a chilled water amount to constantly maintain the chilled water outlet temperature of the load device, and detecting a change in the chilled water amount of the load device and giving an instruction to the chilled water supply means. Means for changing the amount of chilled water supplied from the chilled water supply means. A control device for controlling the temperature and amount of chilled water in the heat storage water tank.