JP3146027B2 - Ice heat storage type heat source device and heat storage amount control method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ice storage type heat source device and a method for controlling the amount of heat stored therein, and in particular, to automatically set and control an optimum amount of heat storage in accordance with, for example, a yearly load change. The present invention relates to a heat storage amount control method for an ice storage heat source device.

[0002]

2. Description of the Related Art In a conventional night-time heat storage operation of an ice storage type heat source device, a predetermined amount of heat storage is ensured in a relatively light load period, such as spring or autumn, as in a midsummer load period. Had control. In addition, as a thing related to this kind, for example, JP-A-1-244228 is cited.

[0003]

In the above prior art, the efficiency of the heat source equipment is reduced by performing heat storage while the heat storage of the previous day remains, water leaks from the pump gland, and water from the heat storage tank. No consideration was given to lowering the water level in the heat storage tank due to evaporation or the like, and there were the following problems. (1) When the heat storage operation is performed in a state in which the load is small and the heat storage of the previous day remains, the thickness of the ice in the heat storage tank becomes unnecessarily thick, so that the heat resistance of the ice is large. Operation at a low evaporation temperature is required, and as a result, the coefficient of performance (COP) of the heat source device during the heat storage operation is reduced.

(2) On a day with a heavy load such that the daytime heat storage is used up, the heat storage start position (water level at the heat storage amount 0) is reset when the heat storage is completely used, and a predetermined time is set from the heat storage start position. By monitoring the rise in the water level (the rise of the water level corresponding to the heat storage amount at the time of completion of the heat storage), even if the water level of the heat storage amount decreases as described above, this can be corrected and the accurate heat storage amount can be managed. However, on a low load day where the load is small and the daytime heat storage is not completely used up, the heat storage cannot be completely used up, so that the heat storage start position cannot be reset. Therefore, in such a case, the heat storage completion position is always fixed at a certain water level, but in such a state, the water leaks from the pump gland or the water evaporates from the heat storage tank. If the water level in the heat storage tank is reduced due to the above, the heat is stored by an amount corresponding to the reduced water level. If such a state continues for a long time, the ice becomes thicker, and the COP of the heat source device during heat storage becomes significantly worse.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and is provided with a means for setting a heat storage amount in accordance with a load state, so that excessive ice icing in a heat storage operation at a partial load. It is an object of the present invention to provide an ice heat storage type heat source device and a heat storage amount control method capable of preventing a decrease in the coefficient of performance (COP) of the heat source device during the heat storage operation by preventing the above.

[0006]

To achieve the above object, an ice storage type heat source device according to the present invention comprises a heat source device.
And a heat storage tank connected to this heat source device, and these heat source devices
Equipped with a heater and control means for controlling the heat storage tank,
To store ice heat and use it as an ice storage heat source device for air conditioning loads.
A water level detector for detecting the amount of ice heat stored in the heat storage tank.
And the inlet and outlet temperatures of the cold water supplied to the load.
First and second temperature detecting means for detecting the temperature;
Temperature detected by the temperature detecting means of at least one season
From the stored temperature data and the stored temperature data.
Calculate the accumulated load of each day and calculate the accumulated load data of each day.
Classification is performed for each predetermined period, and the maximum load is calculated for each predetermined period.
The maximum load for each period is compared with the rated value,
Means for setting an appropriate heat storage amount .

[0007] In order to achieve the above object, the heat storage amount control method for an ice thermal storage type heat source apparatus according to the present invention, nighttime power
Ice storage heat source that uses ice to store ice and uses it for air conditioning loads
In the method for controlling the heat storage amount of the device, the cold water supplied to the load
The temperature of the cold water after cooling the load and the load.
Collect temperature data for at least one season and collect
Calculate the total load for each day from the data and calculate the total load for each day.
The load is divided into predetermined periods, and the maximum load
And the selected maximum load heat amount is the rated heat storage amount.
The heat source device has a heat storage capacity that matches the load
This is set in the control device .

[0008]

The function of the above technical means is as follows. The operation state detection unit according to the means for detecting the state of the load, the chilled water inlet temperature of the ice storage type heat source device at each time,
Detect cold water outlet temperature. The operation state storage unit according to the means for recording the state of the load stores and stores the data detected by the operation state detection unit for a certain period of time, and after the certain period of time has elapsed, based on the data in the operation state storage unit by the microcomputer. The amount of heat load on each operation day is calculated, the required amount of heat storage in each period is determined every month or every half month, and the amount of heat storage is automatically set.

[0009] This makes it possible to perform a proper heat storage operation in each month and each period (full heat storage during a heavy load period, and heat storage according to the load during a low load period). The problem of COP reduction of the heat source equipment due to icing can be solved. In addition, the above-mentioned method, the water leakage from the pump gland portion during the air-conditioning operation with a small load,
Alternatively, even when the water level in the heat storage tank is reduced due to evaporation of water from the heat storage tank, remarkable excessive icing can be avoided, so that the COP can be kept higher than in the conventional method.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 is a system diagram of an ice storage type heat source device according to one embodiment of the present invention, FIG. 2 is a configuration diagram of a microcomputer provided in a control panel of the device of FIG. 1, and FIG. 3 is a heat source in the device of FIG. FIG. 4 is a flowchart showing an example of a conventional ice storage air conditioning system, and FIG. 5 is a flowchart showing an automatic heat storage amount setting method of the ice storage air conditioning system of the present embodiment.

In FIG. 1, 1 is a heat source device, 2 is a brine / water heat exchanger for exchanging heat between the antifreeze cooled by the heat source device 1 and cold water returned from the load during air conditioning operation, 3
Is a heat storage tank that stores heat generated by using nighttime power,
Operates the heat source equipment 1 by using nighttime electric power, causes heat exchange between the low-temperature brine generated and water in the heat storage tank, and
An ice making heat exchanger for making ice therein, 5 a cold water pipe for introducing cold water from a load, 6 a water spray pipe for spraying cold water exiting the brine / water heat exchanger 2 in a heat storage tank 3, 7 and 8 Is a chilled water control valve that controls the amount of chilled water flowing into the heat storage tank 3 to control the chilled water outlet temperature, 9 is a temperature detector that detects the chilled water outlet temperature, and 10 is chilled water control based on a signal from the temperature detector 9. A temperature controller that issues an open / close signal to the valve 8, 11 is a heat source device 1
And a brine / water heat exchanger 2 and an ice making heat exchanger 4.

Reference numerals 12, 13, 14, and 15 denote brine switching valves for switching the flow direction of brine between an air-conditioning operation and a heat storage operation, and 16 estimates a heat storage amount during the heat storage operation and a remaining heat storage amount during the air-conditioning operation. A water level detector for detecting the water level, a conduit for guiding the water level to the water level detector 16, a heat storage tank temperature detector, and a cold water pump. Also, 1
9 is a control panel incorporating a microcomputer, 20 is a chilled water inlet temperature detector of the ice storage type heat source device, and 21 is a chilled water outlet temperature detector of the ice storage type heat source device.

First, the general operation of the ice storage type heat source device will be described. The ice storage type heat source device includes a heat storage operation at night and an air conditioning operation at daytime. In the nighttime heat storage operation, the heat source device 1 (refrigerator) is operated, and the brine in the pipe 11 is reduced to zero.
The temperature is cooled to not more than ℃, and heat is stored by changing the water in the heat storage tank 3 to ice. Normally, the heat storage operation as described above is performed during the night discount time period (22:00 to 8:00). In order to reduce the size of the heat source device 1, there is also a method of performing a heat storage operation in addition to the night discount time zone. In addition, the heat storage amount is constantly measured by the water level detector 16 from a reference position (a position where the heat storage amount is zero), and when the water level difference reaches a predetermined value, it is determined that the heat storage is completed, and the heat storage operation is performed. To end.

Next, in the daytime cooling operation, the heat source equipment 1 (refrigerator) is operated to cool the brine to about 3 ° C. and guide the brine to the brine / water heat exchanger 2, where it returns from the load. By performing heat exchange with the cold water, the temperature of the cold water provided to the watering pipe 6 is lowered. Further, the control valves 7 and 8 are controlled by the temperature detector 9 and the temperature controller 10 so that the chilled water that has exited the brine / water heat exchanger 2 has a predetermined temperature (for example, 7 ° C.) at the outlet of the unit. I do.

In the operation / stop control of the heat source equipment 1, the difference in water level from the reference water level detected by the water level detector 16 is converted into a heat storage amount in the microcomputer, as shown in FIG. It is controlled inside the microcomputer by a running / stop curve as shown. Here, the microcomputer is
As shown in FIG. 2, the CPU 24, the memory 22, the CPU
A bus 23 for transmitting data between the CPU and a memory, an input interface 25 for receiving an external signal and converting the signal into a signal for the CPU, and the input interface 25 and the CP
Cable 28 for transmitting data to and from U24, CPU
An output interface 26 for converting a signal from the external device 24 into a signal for an external device, and a cable 2 for performing data transmission between the CPU 24 and the output interface 26
7 for processing input signals and output signals in accordance with software logic stored in the memory 22. The above-described heat storage operation control and air conditioning operation control are controlled by a control panel 19 having the microcomputer therein.

Next, automatic heat storage amount control, which is a feature of the present invention, will be described with reference to FIGS. 4 and 5 in comparison with a conventional control method. In the following text, the step numbers of the flowchart in the figure are written in parentheses. First, a control method of the conventional ice storage type heat source device will be described with reference to FIG. The ice storage type heat source device sets an operation schedule such as an air-conditioning start time, an air-conditioning end time, and a heat storage start time (Step 30), and starts operation (Step 31).

After the start of operation, it is determined whether the current time is neither the air conditioning operation time nor the heat storage operation time of the input schedule (steps 32 and 41). If the current time is the air-conditioning operation time, the chilled water pump 29 starts (step 33), and the microcomputer issues a start command or a stop command to the heat source device 1 based on the start / stop control curve of the heat source device 1 (chiller) in FIG. put out. If a start command is issued at this point (step 34), the heat source device 1 starts operating (step 35). When the start command is not issued, the heat source device 1 is stopped, and air conditioning is performed by storing heat in the heat storage tank 3.

When the air conditioning operation as described above is performed and the air conditioning end time set in the schedule comes, the heat source device 1 is stopped (steps 37, 38, and 39). Next, when the heat storage time comes, the heat source device 1 starts operating and performs an ice making operation (steps 41 and 42). Then, when the heat storage is completed (when the rated heat storage amount is stored), or when the heat storage time has ended, the heat source device 1 stops and ends the heat storage operation (steps 43 and 44).

Next, an automatic heat storage amount control method will be described with reference to FIG.
It will be described according to. In FIG. 5, those having the same step number are the same steps as those in the conventional control method, and the hatched portions are the features of the present embodiment. The air-conditioning operation is started, and the chilled water pump 29 is started (Step 33).
And a chilled water inlet temperature detector 20 and a chilled water outlet temperature detector 21
Detects the cold water inlet temperature and the cold water outlet temperature of the ice storage type heat source device, respectively, and sends the detected data to the microcomputer of the control panel 19. In the microcomputer, the sent temperature data is sequentially stored in the memory, and the operation data is collected (step 46). Such data collection is continued for a certain period, such as one season or one year. The collection period is set when the operation schedule is set (step 3
0) or a method of storing the initial values in the microcomputer in advance.

When the data collection is completed for a certain period of time (step 47), the integrated load of each operation day is calculated from the accumulated operation data (step 48). Next, one year
Every month, every six months, or every 10 days, the heat load is divided for each fixed period, the maximum heat load during that period is selected (step 49), and it is determined whether the load is equal to or more than the rated heat storage amount. The heat storage amount is set in the microcomputer (step 50). When performing the above setting, it is possible to make a setting with a margin for the load. It is also possible to calculate a daily integrated load at the time of collecting the daily operation data, and store the calculation result in the microcomputer.

The hardware for performing the above-mentioned control uses the microcomputer, which has been performing the conventional operation schedule, starting and stopping of the heat source device 1, and controlling the amount of stored heat, by time sharing. In addition to setting the amount, it is also possible to prepare a dedicated microcomputer for automatic heat storage amount control and execute the processing in parallel. When the above-described automatic heat storage amount control is performed, the start / stop curve in FIG. 3 for performing the chiller start / stop control is also corrected as indicated by a broken line in accordance with the load. In addition, the setting of the heat storage amount corresponding to the load can also be realized by inputting a schedule of the heat storage operation in each period to the microcomputer based on the experience of the operator.

According to the present embodiment, the amount of heat storage can be automatically set in accordance with the load of each air-conditioning object (for example, a building) in each season. Driving can be realized.

[0023]

As described above in detail, according to the present invention, a means for setting the amount of heat storage corresponding to the load condition is provided to prevent excessive icing of ice in the heat storage operation at a partial load. Gives the coefficient of performance (C
OP) It is possible to provide an ice heat storage type heat source device capable of preventing a decrease in OP) and a heat storage amount control method thereof.

[Brief description of the drawings]

FIG. 1 is a system diagram of an ice storage type heat source device according to one embodiment of the present invention.

FIG. 2 is a configuration diagram of a microcomputer provided in a control panel of the apparatus of FIG.

FIG. 3 is a diagram of start / stop control of a heat source device in the apparatus of FIG. 1;

FIG. 4 is a flowchart showing an example of a conventional ice storage air conditioning system.

FIG. 5 is a flowchart illustrating an automatic heat storage amount setting method for the ice heat storage air conditioning system according to the present embodiment.

[Explanation of symbols]

 Reference Signs List 1 heat source device 2 brine / water heat exchanger 3 heat storage tank 9 temperature detector 10 temperature controller 16 water level detector 18 heat storage tank temperature detector 19 control panel 20 chilled water inlet temperature detector 21 chilled water outlet temperature detector 22 memory 24 CPU

Claims (2)

(57) [Claims] An ice storage device comprising: a heat source device; a heat storage tank connected to the heat source device; and control means for controlling the heat source device and the heat storage tank. In the regenerative heat source device, a water level detector for detecting the amount of ice heat stored in the heat storage tank is provided, and first and second temperature detecting means for detecting an inlet temperature and an outlet temperature of cold water supplied to a load; Storage means for storing the temperatures detected by the first and second temperature detecting means for at least one season; calculating the integrated load of each day from the stored temperature data; Means for determining a maximum load for each predetermined period, comparing the maximum load for each period with a rated heat storage amount, and setting a heat storage amount corresponding to the load. Ice storage heat source device. 2. A method for controlling the amount of heat stored in an ice storage type heat source device that stores ice heat using nighttime electric power and that is used for an air-conditioning load, comprising: a temperature of cold water supplied to the load and a temperature of cold water after cooling the load. , Temperature data for at least one season is collected, the integrated load for each day is calculated from the collected data, the integrated load for each day is divided into predetermined periods, and the maximum load calorie is selected for each period. And comparing the selected maximum load heat amount with a rated heat storage amount, and setting a heat storage amount corresponding to the load in a control device provided in the heat source device.