JP2986425B2 - Air conditioning control method for heat storage air conditioning system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioning control method for a heat storage air conditioning system.

[0002]

2. Description of the Related Art In recent years, in office buildings and the like, advanced functions such as computerization, automation, and comfort have been advanced, and as a result, the load of cooling air conditioning has increased remarkably. I have. Therefore, in order to cope with such an increase in the cooling air conditioning load, an ice storage air conditioning system for the purpose of load leveling has been developed.

[0003] This ice thermal storage air conditioning system makes and stores ice and the like in the nighttime hours when the electricity rate is low, and in the daytime air conditioning time period, the thermal storage air conditioning using the thermal storage and the normal air conditioning not using the thermal storage are used. The cooling is performed by combining the above. By the way, in general, in air conditioning for one day, the air conditioning load becomes extremely large during a time when the outside air temperature and room temperature are extremely high, and in such a peak time of the air conditioning load, the power consumption for air conditioning significantly increases. I do.

Therefore, the present invention has been made in view of the above circumstances,
Reduce power consumption during peak hours of air conditioning load,
It is an object of the present invention to provide a new air-conditioning control method for a heat storage air-conditioning system capable of realizing air-conditioning load leveling.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems by providing a heat storage air conditioning system that performs heat storage air conditioning using heat storage and normal air conditioning that does not use heat storage.
The air conditioning time zone of the day is divided into a first time zone, a second time zone, and a third time zone in order, and in the first time zone, heat storage air conditioning and normal air conditioning are performed based on the residual ice prediction curve, and the second time In the third period, air conditioning control is performed so that normal air conditioning is stopped and only heat storage air conditioning is performed, and in the third time period, heat storage air conditioning and normal air conditioning are performed based on the residual ice prediction curve. Using the number, the remaining heat storage amount at the end of the third time zone of the previous day, and the available sensible heat amount in the heat storage tank, the time zone length of the second time zone of the present day is obtained, and further, the time zone of the second time zone of the present day The length of the day is the number of hours of normal air conditioning
An air-conditioning control method for a thermal storage air-conditioning system, characterized in that the air-conditioning control method of the heat storage air-conditioning system is corrected based on an increase amount of a load of a first time zone of the present day with respect to the previous day and an incremental load ratio of a today's first time zone and an air conditioning time zone. provide.

The present invention also provides the control method as described above, wherein the time zone length of the second time zone of the present day is determined by: And the sum of the available sensible heat in the heat storage tank (Claim 2), and the number of hours of normal air-conditioning suspension for the first time period of the day, Correcting the time zone length of the second time zone by subtracting the increase in the time zone load with respect to the previous day multiplied by the incremental load ratio of the first time zone and the air conditioning time zone of the present day (claim 3) Or the amount of increase in the first hour load of the day versus the previous day,
The amount of residual ice at the end of the first time zone of the previous day, the number of normal air conditioning suspension hours at the end of the first time zone of the previous day, the amount of residual ice at the end of the first time zone of the day, and the normal Calculating using the number of air-conditioning stop time (claim 4)
Are preferred embodiments.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, the air-conditioning control method for a heat storage air conditioning system according to the present invention comprises, as described above, a heat storage air conditioner using heat stored by ice or the like stored in a heat storage tank and a normal air conditioner not using heat storage. It is a method of controlling the air conditioning of the heat storage air conditioning system to be performed, wherein the air conditioning time period of the day arbitrarily set in advance,
The air conditioning time zone is divided into a first time zone, a second time zone, and a third time zone in order from the start time, and in the first time zone and the third time zone, the heat storage air conditioning and the normal air conditioning are performed based on the residual ice prediction curve. Then, in the second time zone, the air conditioning is controlled so that the normal air conditioning is stopped and only the heat storage air conditioning is performed.

[0008] The second time zone is a time zone including a time when the air-conditioning load peaks in the air-conditioning time zone of the day,
In the air-conditioning control method of the present invention, the time zone length of the second time zone is set to the total number of normal air-conditioning suspension hours of the previous day, the remaining heat storage amount at the end of the third time zone of the previous day, and the available sensible heat amount in the heat storage tank. And further corrected by the number of hours of normal air conditioning suspension for the first time zone of the day, the amount of increase in the load of the first time zone of the day to the previous day, and the incremental load ratio between the first time zone of the day and the air conditioning time zone of the day. I do.

More specifically, the residual ice prediction curves used in the first time zone and the third time zone are, for example, the air-conditioning load prediction characteristics in the air-conditioning time zone of the day illustrated in FIG. As illustrated, the estimated value of the residual ice amount at each time when the heat storage air conditioning and the normal air conditioning are shared based on the air conditioning load of the heat storage air conditioning and the air conditioning load of the normal air conditioning. It shows. FIG. 3 shows an example of such a residual ice prediction curve. A dead zone having an arbitrary width may be provided in the residual ice prediction curve to set the upper limit and the lower limit of the residual ice amount, or the residual heat storage amount may be used instead of the residual ice amount.

In the first time zone and the third time zone,
Based on the residual ice amount value or the upper and lower limit values shown in such a residual ice prediction curve, for example, when the residual ice amount value or the upper limit value is exceeded, that is, when the actual air conditioning load is smaller than the predicted air conditioning load, When the normal air conditioning is stopped and only the heat storage air conditioning is performed, and when the remaining ice amount value or the lower limit value at each time is lower, that is, when the actual air conditioning load is larger than the predicted air conditioning load, the normal air conditioning is performed. Air-conditioning control is performed so as to perform more.

In the second time zone including the peak time of the air conditioning load, near the peak time of the air conditioning load, when the normal air conditioning is used, an extremely large amount of electric power is required. The air conditioning is controlled so that the normal air conditioning is stopped and only the heat storage air conditioning is performed. The time zone length of the second time zone of this day is the total number of normal air conditioning stoppage times in the first time zone, the second time zone, and the third time zone of the previous day, the end of the third time zone of the previous day, It is determined by adding the remaining heat storage amount at the end of the time zone and the available sensible heat amount in the heat storage tank, which is the sensible heat amount that can be used for air conditioning.

Further, the remaining heat storage amount at the end of the third time zone of the previous day is calculated by subtracting the heat amount corresponding to the water temperature in the heat storage tank from the remaining ice heat amount. Further, from the time zone length of the second time zone of the present day to the number of ordinary air conditioning stoppage times of the first time zone of the present day, and the increase of the load of the first time zone of the day with respect to the previous day, the first time zone of the today and the air conditioning time The time zone length of the second time zone is corrected by subtracting the value multiplied by the incremental load ratio with the zone.
The incremental load ratio between today's first time zone and the air conditioning time zone is arbitrarily set according to the load form of the building or the like to be air-conditioned.

The increase in the load of the first time zone with respect to the previous day, which is used for correcting the time zone length, is calculated by calculating the amount of residual ice at the end of the first time zone on the previous day and the number of hours of normal air conditioning suspension in the first time zone. It is calculated by subtracting the sum of the amount of ice remaining at the end of the first time zone and the number of normal air-conditioning suspension hours in the first time zone from the sum, and calculating the remaining time at the end of the first time zone. As the amount of ice, a value obtained by dividing the amount of residual ice heat at the end of the first time zone by the refrigeration function of normal air conditioning is used.

In this manner, the length of the time period during which normal air conditioning is stopped and only heat storage air conditioning is performed can be efficiently obtained, the power usage fee in the time zone near the peak time of the air conditioning load is reduced, and the air conditioning load is leveled. Can be realized. In the air-conditioning control method of the present invention, for example, an upper limit value is arbitrarily set for the time zone length of the second time zone, and when the time zone length of the second time zone exceeds the upper limit length value, Forcibly stop thermal storage air conditioning at the upper limit length value,
The second time zone may be ended.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

[0016]

FIG. 4 shows an example of an ice storage air conditioning system which is air-conditioned by the air-conditioning control method of the present invention. In the ice thermal storage air conditioning system illustrated in FIG.
(1) is an air-cooled chiller, (2) is an ice heat storage tank, (3) is a brine pump, (4) is a mixed three-way valve for controlling cold water temperature,
(5) is an ice making coil, (6) is a brine coil, (7)
Is a cold water coil, (8) is a cold water pipe, (9) is a brine pipe, (10) is a cold water outlet temperature sensor, (11) is a cold water inlet temperature sensor, (12) is a heat storage tank temperature sensor, (1)
3) is a water level sensor in the heat storage tank for calculating the amount of ice, and 14 is a microcomputer for controlling the whole system.

In the ice heat storage air conditioning system, during the night heat storage time period, the brine is cooled by the brine coil (6), and the ice is made to accumulate on the ice making coil (5) installed in the ice heat storage tank (2). To store ice. In a time zone other than the heat storage time zone, for example, the air conditioning time zone, the brine coil (6) is stopped, and the return water from the external air conditioner is cooled by the cold water coil (7). The outlet temperature of the chilled water sent to the external air conditioner during the air conditioning time period is determined by a chilled water outlet temperature sensor (1).
0), and is adjusted to be always 7 ° C., for example.

When the normal air conditioning and the thermal storage air conditioning are combined, the chilled water outlet temperature is always adjusted to 7 ° C., so that the normal air conditioning load by the cold water from the air cooling chiller (1) and the total air conditioning load are reduced. Is controlled so as to compensate for the difference load by the heat storage air conditioning using the ice storage in the ice heat storage tank (2). The adjustment of the chilled water outlet temperature at this time is performed by adjusting the amount of chilled water from the air-cooled chiller (1) and the amount of chilled water from the ice heat storage tank (2) by a mixed three-way valve (4) for controlling chilled water temperature.

When the normal air conditioning is stopped, the return water from the external air conditioner passes through the chilled water coil (7) as it is, and a part thereof is distributed to the ice heat storage tank (2). Mix again with the three-way valve (4) and adjust the cold water outlet temperature to 7 ° C. The air conditioning system of FIG. 4 that operates as described above is air-conditioned by the air-conditioning control method of the present invention, for example, in accordance with each control process shown in FIG.

In the control illustrated in FIG. 5, the air-conditioning time zone of the day is set from 8:00 to 18:00, the first time zone is from 8:00 to 13:00, the second time zone is from 13:00 to tp, and tp The third time zone is from time to 18:00, and the second time zone includes the air conditioning load peak time. First, in the first time zone, normal air conditioning with cold water from the air-cooled chiller (1) and heat storage with ice storage in the ice heat storage tank (2) are performed according to a residual ice prediction curve set in advance based on the air conditioning load characteristics. The air conditioning is used in combination.

In the next second time period, the air-cooling chiller (1) is stopped to stop the normal air conditioning, and only the heat storage air conditioning is performed. The time zone length of this second time zone, that is, tp from 13:00
The time length until the time is, for example, before the end of the air conditioning time zone (third time zone) of the previous day, the total number of normal air conditioning suspension hours of the previous day, the remaining heat storage amount at the end of the third time zone of the previous day, and the heat storage tank. It is calculated using the amount of available sensible heat in the air, and at the start of the second time zone of the day, the number of hours of normal air conditioning stoppage of the first time zone of the day, the amount of increase in the load of the first time zone of the day before the day , And the incremental load ratio between today's first time zone and air conditioning time zone.

When the second time zone having the time zone length obtained by the correction as described above ends and enters the third time zone, the air-cooled chiller (1) is started again, and the residual ice prediction curve is displayed. Along with this, normal air conditioning and heat storage air conditioning are performed. When the third time zone ends, the time zone length of the second time zone of the next day is calculated. Of course, this calculation may be performed any time before the start of the second time zone.

The heat storage at night starts at 22:00, and is used for heat storage air conditioning on the next day. In such an air conditioning control method of the present invention, the setting of the residual ice prediction curve used in the first time zone and the third time zone is, for example, that the residual ice prediction curve in the first time zone has a tendency of remaining ice, that is, the heat storage. Normal air conditioning is performed more than air conditioning, and heat storage is set to remain more than the second time zone.The residual ice prediction curve in the third time zone tends to thaw, that is, heat storage at the end of the third time zone Is preferably set so as not to remain.

FIG. 6 shows a residual ice prediction curve used in the air conditioning control according to the present invention as described above, and FIG. 7 shows actual actual air conditioning and thermal storage air conditioning in the air conditioning load time zone. This is an example of load sharing. In FIG. 6, a curve shown by a dotted line is a set residual ice prediction curve, and a curve shown by a solid line represents a residual ice amount at each time actually obtained by air-conditioning control by the air-conditioning control method of the present invention. In the first time zone and the third time zone, normal air conditioning and heat storage air conditioning are performed along the dotted line residual ice prediction curve, and the change in the amount of residual ice when only the heat storage air conditioning is performed in the second time zone is shown. I have.

Further, as is apparent from FIG. 7, according to the air conditioning control method of the present invention, only the heat storage air conditioning is performed in the second time zone including the air conditioning load peak time zone. Of course, the present invention is not limited to the above-described example, and it goes without saying that various aspects are possible in detail.

[0026]

As described in detail above, the air conditioning control method for a thermal storage air conditioning system according to the present invention makes it possible to easily and accurately control the normal air conditioning and the thermal storage air conditioning corresponding to the air conditioning load form and daily load changes. Thus, it is possible to reduce the amount of electric power used during the peak time period of the air conditioning load, and realize the leveling of the air conditioning load.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of air conditioning load characteristics for one day.

FIG. 2 is a diagram showing an example in which the air conditioning load characteristics of FIG. 1 are shared by a heat storage air conditioning load and a normal air conditioning load.

FIG. 3 is a diagram exemplifying an ice melting prediction line based on the air conditioning load characteristic of FIG. 2;

FIG. 4 is a configuration diagram showing an example of an ice storage air conditioning system controlled by the air conditioning control method of the present invention.

FIG. 5 is a diagram showing an example of each control process in the air conditioning control method of the present invention.

FIG. 6 is a diagram exemplifying a residual ice prediction curve and an actual residual ice curve.

FIG. 7 is a diagram exemplifying actual load sharing of normal air conditioning and heat storage air conditioning in an air conditioning load time zone.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air-cooled chiller 2 Ice heat storage tank 3 Brine pump 4 Mixed three-way valve for cold water temperature control 5 Ice making coil 6 Blind coil 7 Cold water coil 8 Cold water pipe 9 Brine pipe 10 Cold water outlet temperature sensor 11 Cold water inlet temperature sensor 12 Temperature sensor inside heat storage tank 13 Water level sensor in heat storage tank 14 Microcomputer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-172383 (JP, A) JP-A-64-38544 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F24F 11/02 102

Claims (2)

(57) [Claims] 1. Heat storage air conditioning using heat storage and no heat storage
For a thermal storage air-conditioning system that performs normal air conditioning, the air-conditioning time periods of the day are sequentially set to the first time zone, the second time zone, and
And the third time zone.In the first time zone, heat storage air conditioning based on the residual ice prediction curve and
Normal air conditioning is performed, and during the second time period, normal air conditioning is stopped and only thermal storage air conditioning is performed.
In the third time period, heat storage air conditioning based on the residual ice prediction curve and
This is a method of controlling air conditioning so that normal air conditioning is performed.WhenEnd of the third day of the previous day
Heat storage at the timeWhenAvailable sensible heat in the heat storage tankWhenToAdd
By matchingFind the time zone length of today's second time zone
Me,  further,thisTime zone length of today's second time zoneFromtoday's
First time zoneInNormal air conditioning stop time,andtoday's
First time load increase from previous dayToToday's first time zone and sky
Incremental load ratio with adjustment time zoneDraw what is multiplied byBy
R, The time zone length of today's second time zoneFeatures to correct
Air conditioning control method for a heat storage air conditioning system. 2. The amount of increase in the load of the first time zone of the day with respect to the previous day.
Is, of the remaining ice volume and the day before at the end of the day before the first time zone of
The sum of the number of normal air conditioning suspension hours in the first time zone
From the amount of residual ice at the end of today's first time zone and today
Of normal air-conditioning suspension time in the first time zone of
2. The air-conditioning control method for a heat storage air-conditioning system according to claim 1, wherein the value is obtained by subtracting