JPH07318116A - Air conditioner - Google Patents

Abstract

PURPOSE:To efficiently operate a cooling operation by multiplying a value obtained by subtracting the residual ice amount of a previous day from an icemaking amount calculated from a mean daytime atmospheric temperature for previous several days of a predetermined day by a coefficient, and setting a target icemaking amount of a heat accumulator, CONSTITUTION:If a signal from a water level sensor 15 has residual ice, the calculator of a controller 22 calculates a target icemaking amount G from an equation of G={f(t)-g}Xa by considering the amount G. f(t) is, for example, a value obtained by calculating from the atmospheric temperature of daytimes of previous three days, g is a residual ice amount, and the coefficient alpha is preferably 0.4-0.8. Water 9 is frozen to ice 26 by the operation of a heat exchanger 10 for icemaking by transferring to an icemaking operation. When an ice thickness sensor 12 is OFF, it is iced to the amount G. When the sensor 12 is turned ON, the icemaking operation is stopped, a cooling operation is started, and it is so operated as to fully use the ice 26. Accordingly, the generation of the residual ice at an intermediate season having relatively small cooling load is prevented to efficiently conduct the cooling operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for air-conditioning (cooling) a room with heat stored in a heat storage device.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 5-50672 discloses an air conditioner of this type.

The air conditioner disclosed in this publication stores the heat obtained by a refrigerator (chiller unit) in a heat accumulator (makes ice), and cools the cold water generated by this heat in an indoor air conditioner. It is intended to guide the air to the heat exchanger and air-condition the room.

By the way, in recent building air-conditioning systems, the amount of heat generated by a computer or the like installed in a computer room is increasing, so that the indoor cooling period is expanding not only in summer, but also in early spring, autumn, and early winter. When air conditioning the room with such an air conditioner, the amount of ice made in the heat accumulator does not remain in the summer when the cooling load is large, but remains in the early spring, autumn, or early winter when the cooling load is relatively small. Will end up. This is because the amount of ice making is set in the heat storage tank in consideration of air conditioning in the summer.

[0005]

If ice remains in the heat accumulator, the water level in the heat accumulator rises during the middle of spring, autumn, and early winter, and an ice thickness control sensor (described later) is used. May give an abnormal alarm. Generally, the following measures have been conventionally taken to prevent as much ice as possible from remaining when performing such air conditioning by ice heat storage.

(1) As shown in FIG. 3, when the cooling load is large in summer or for long-term cooling, the all-day mode is set and the target ice making amount G is set by calculation.

This target ice making amount G is, as shown in FIG.
It is represented by G = f (t) -g (%). Where f (t)
Is a value calculated by calculating the outside air temperature during the daytime for the previous three days, and g (%) on the previous day indicates the amount of residual ice.

(2) When the air conditioner is operated in early spring, autumn, early winter, etc., the so-called half-day mode is manually selected to set the target ice-making amount to 100% (maximum heat storage amount in the regenerator). ), The amount of ice making is set to 10% of the amount of ice making manually.

(3) When the control ice thickness sensor is activated and an alarm is issued after the residual ice in the heat storage tank continues, the ice making operation is stopped at that time.

(4) The presence or absence of residual ice is monitored by the water level in the heat storage tank.

However, the method according to (1) cannot reliably control the residual ice during the intermediate period when the temperature change is remarkable.
Since the method according to (2) is manual, the operation is complicated, and as in (1), reliable control cannot be performed during the intermediate period when the temperature changes significantly. In the method according to (3) and (4),
It is not possible to operate to remove the remaining ice in advance, and energy is wasted.

Further, the amount of ice is grasped by the amount of change in the water level in the heat storage tank due to the volume change of ice and water, and when the remaining ice continues,
The influence of water leak from the pump becomes large and the amount of ice cannot be accurately captured. Therefore, there is a drawback that the target ice-making amount is calculated too much.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an air conditioner capable of performing an efficient cooling operation by executing the minimum necessary heat storage.

[0014]

Therefore, the first invention is
A refrigerator and a heat accumulator that stores the heat obtained by this refrigerator,
In an air conditioner consisting of an air conditioner that controls the temperature of the room using the heat of this heat accumulator, if residual ice is detected in the heat accumulator on the day before the day on which this equipment is operated, The target ice-making amount of the heat accumulator is obtained by multiplying the value obtained by subtracting the remaining ice amount g of the previous day from the ice-making amount f (t) calculated from the average outside temperature t during the previous several days by a coefficient α smaller than 1. A control device for setting G is provided.

The second aspect of the invention is an air comprising a refrigerator, a heat accumulator for storing the heat obtained by the refrigerator, and an air conditioner for controlling the temperature in the room using the heat of the heat accumulator. In the harmony device, when residual ice is detected in the heat accumulator on the day before the predetermined day when the device is operated, the ice making amount f calculated from the average outside temperature t during the day for several days on the predetermined day.
The value obtained by subtracting the remaining ice amount g of the previous day from (t) is 0.
It is provided with a control device for setting the target ice making amount G by multiplying the coefficient α which is 4 to 0.8.

[0016]

According to the first aspect of the invention, the control device multiplies the value obtained by subtracting the amount of residual ice g from the average outside air temperature f (t) during the day before a predetermined number of days by a coefficient α smaller than 1. Since the target ice-making amount G is set by the above, an accurate amount of ice can be obtained according to the cooling load on the predetermined day when the air conditioner is operated, and the generation of residual ice in the heat accumulator can be prevented, resulting in an efficient operation. Air conditioning operation is possible.

According to the second invention, the coefficient α is set to 0.
Since it is set to 4 to 0.8, it is possible to reliably obtain an accurate ice amount according to the cooling load, and it is possible to reliably prevent generation of residual ice, so that more efficient cooling operation can be performed.

The coefficient α is set to 0.4 to 0.8. If the coefficient α is smaller than 0.4, the amount of ice making may be too small in early spring, autumn, or early winter, and the coefficient α is 0. If it is larger than 0.8, the amount of ice making may be too large in early spring, autumn or early winter.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a preferred circuit example of the air conditioner of the present invention.

In FIG. 1, reference numeral 1 denotes an air conditioner including a refrigerator (hereinafter referred to as a chiller) 2, a heat storage device 3, an air conditioner 4 such as a fan coil installed indoors, and a control device 2.
2 and.

The chiller 2 comprises a compressor 5, a condenser 6, a decompressor 7, and an evaporator (water heat exchanger) 8, and these devices are connected by a refrigerant pipe.

Water 9 is stored in the heat storage device 3, and the heat exchanger 10 for ice making converts the water 9 into ice 26 to perform heat storage.

The heat exchanger 10 for ice making and the evaporator 8 are
It is connected via a brine pump 13 and a first opening / closing valve 14. Reference numeral 15 is a float structure ice making sensor (water level sensor), and 12 is an electrode type ice thickness sensor.

Here, water 9 is produced by the action of the ice-making heat exchanger 10.
When the ice starts to freeze, the volume expansion of the ice 26 causes the heat storage device 3
The water level inside rises. This rise in water level is detected by the ice making sensor 15.
Is detected and the amount of ice in the heat storage device 3, that is, the amount of heat storage is obtained.

Reference numeral 16 is a brine / water heat exchanger, one end of which is provided between the first opening / closing valve 14 and the evaporator 8 via the second opening / closing valve 17, and the other end of which is the heat storage unit 3 and the brine pump 13. They are connected to each other.

A heat exchanger 18 for air conditioning is arranged in the air conditioner 4, and the heat exchanger 18 for air conditioning has an inlet end for absorbing heat of the heat accumulator 3 via a chilled water pump 19 and a three-way valve 20. It is connected to the exchanger 21. On the other hand, the outlet end of the air conditioning heat exchanger 18 is branched via the brine / water heat exchanger 16 and is connected to the three-way valve 20 and the heat absorption heat exchanger 21.

Reference numeral 22 denotes a control device, which is the water level sensor 15 described above.
Input device 2 that receives the signal from the terminal, that is, the amount of heat storage (the amount of ice)
3, a clock 24 for measuring the time of day, an output device 25 for outputting a signal to the compressor 5 of the chiller 2 based on signals from both, and an arithmetic unit 27.

In this air conditioner 1, heat storage operation is performed from nighttime when the electricity charge is low (for example, from 10 pm to 8:00 am on the next day). That is, the chiller 2 and the brine pump 13 are operated, the first opening / closing valve 14 is opened, the second opening / closing valve 17 is closed, and the brine obtained in the evaporator 8 of the chiller 2 is flowed as indicated by a solid arrow. , Regenerator 3
The water 9 therein is changed to ice 26 (heat storage operation).

During the cooling operation, first, the operation of the chiller 2 is stopped and only the chilled water pump 19 is operated, so that the water cooled by the ice 26 in the heat storage device 3 is air-conditioned as indicated by the solid line arrow. It is sent to the heat exchanger 18 for use. As a result, the room is cooled.

With the cooling operation, the amount of ice 26 gradually decreases. Due to this decrease, when the amount of ice 26 becomes equal to or less than the target value (this target value changes (decreases) with time), the chiller 2 is operated again. This operation is called chasing operation.

During this chasing operation, the brine and the cold water flow as indicated by the broken line arrow. That is, when the air conditioning load (cooling load) is low and / or the heat exchange rate in the brine / water heat exchanger 16 is high, the cold water flowing out from this brine / water heat exchanger 16 is sufficiently cooled. At this time, the heat storage device 3 is bypassed and is guided to the cold water pump 19 via the three-way valve 20.

In the opposite case, it is led to the cold water pump 19 via the heat storage device 3 and the three-way valve 20. At this time, the heat storage amount (ice amount) of the heat storage unit 3 is sufficiently stored.

Next, the operation of the air conditioner of the present invention will be described with reference to FIG.

First, the all-day mode will be described.

The control device 22 determines from the signal from the water level sensor 15 whether there is residual ice (step S).
1). If there is residual ice, the calculation unit 27 of the control device 22.
However, as shown by the following equation (1), the target ice making amount G is calculated in consideration of the residual ice correction.

[0037]

[Mathematical formula-see original document] f (t) in the calculation formula of this target ice making amount G
Is a value (average outside air temperature) calculated from the outside air temperature in the daytime for the previous three days, and g is the amount of residual ice. The coefficient α is preferably 0.4 to 0.8, and particularly preferably 0.5. If the coefficient α is less than 0.4, the amount of ice making may be too small in early spring, autumn, or early winter, and if the coefficient α is more than 0.8, the amount of ice making may be large in early spring, autumn, or early winter. Because it is too much.

When the coefficient is 0.5, the target ice making amount G is reduced by 50% compared with the all-day mode (step S
2).

Then, in the ice making operation, the water 9 is turned into ice 26 by the action of the ice making heat exchanger 10 (step S3). When the ice thickness sensor 12 is off (step 4A), the target ice making amount G is made (step S7). When the ice thickness sensor 12 is turned on (step 4A) (step S
4), the ice making operation is stopped (step S8), and the normal cooling operation is started (step S9).

Then, the operation is performed so that the ice 26 in the heat storage device 3 is used up (step S10).

If the water temperature in the heat storage unit 3 falls below, for example, 7 ° C, the air conditioning operation is continued, and if the water temperature in the heat storage unit 3 exceeds, for example, 7 ° C, a chiller chase operation is performed during the air conditioning operation. To do.

Next, the case where there is no residual ice will be described.

In step S1, since the remaining ice amount is zero (step S4), the arithmetic unit 27 of the control device 22
In the above equation, the equation for the target ice making amount G is not multiplied by the coefficient α. That is, the calculation formula of the target ice making amount G is not corrected. Then, the reference water level is measured to make ice up to the target ice making amount G (step S7).

After the ice making up to the target ice making amount G, steps S8 to S12 are carried out as described above.

As described above, if there is no extreme decrease in the load, the remaining ice disappears the day after the remaining ice occurs, and the abnormality (abnormal ice thickness) that occurs when the remaining ice continues for several days does not occur.

By the way, the present invention can be variously modified without departing from the scope of the claims.

For example, f in the equation for calculating the target ice making amount G
(T) is not limited to a value (average outside air temperature) calculated from the daytime outside air temperature for the previous three days, but is calculated from the daytime outside air temperature for the previous two days or four days or more. The calculated value (average outside temperature) may be used.

[0048]

As described above, according to the first aspect of the present invention, when the full-day mode is selected in the middle period such as early spring, autumn, or early winter, the control device controls the number of days before the predetermined number of days. Since the target ice-making amount G is set by multiplying the value obtained by subtracting the remaining ice amount g from the daytime average outside temperature f (t) in the above by the coefficient α smaller than 1, the accurate ice amount according to the cooling load is set. You can get it and there will be no remaining ice. As a result, it is possible to prevent the generation of residual ice during the intermediate period when the cooling load is relatively small, and to perform efficient cooling operation. That is, efficient cooling operation can be performed by effectively storing the minimum required heat. Further, the false alarm due to the remaining ice is not issued, and the influence of water leakage from the pump is eliminated, so that the ice amount can be accurately measured.

According to the second invention, the coefficient α is set to 0.
Since it is set to 4 to 0.8, it is possible to reliably obtain an accurate ice amount according to the cooling load, and it is possible to reliably prevent generation of residual ice, so that more efficient cooling operation can be performed. This makes it possible to obtain an accurate amount of ice according to the cooling load, and reliably prevent the generation of residual ice.

[Brief description of drawings]

FIG. 1 is a diagram showing a preferred circuit example of an air conditioner of the present invention.

FIG. 2 is a flowchart showing a series of operations in the circuit of FIG.

FIG. 3 is a flowchart showing a series of operations in a circuit of a conventional air conditioner.

[Explanation of symbols]

 2 Refrigerator 3 Heat accumulator 4 Air conditioner 22 Controller α coefficient

Claims (2)

[Claims] 1. An air conditioner comprising a refrigerator, a heat accumulator for storing the heat obtained by the refrigerator, and an air conditioner for controlling the temperature in the room by using the heat of the heat accumulator. When residual ice is detected in the heat accumulator on the day before the predetermined day when the vehicle is operated, the residual ice on the previous day is calculated from the ice-making amount f (t) calculated from the average outside temperature t during the day in the days preceding the predetermined day. An air conditioner comprising a control device that sets a target ice making amount G of the heat storage unit by multiplying a value obtained by subtracting the amount g by a coefficient α smaller than 1. 2. An air conditioner comprising a refrigerator, a heat accumulator that stores heat obtained by the refrigerator, and an air conditioner that controls the temperature of the room by using the heat of the heat accumulator. When residual ice is detected in the heat accumulator on the day before the predetermined day when the vehicle is operated, the residual ice amount on the previous day is calculated from the ice-making amount f (t) calculated from the average outside temperature t during the day during the predetermined days. The coefficient α, which is 0.4 to 0.8, is obtained by subtracting g.
An air conditioner comprising a control device that sets a target ice-making amount G by multiplying by.