JPS6350620B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optimal activation control method for an air conditioning system for multiple rooms.

[Conventional technology]

An example of the system of the central control device and local control device in this type of air conditioning system is shown in Fig. 1 and explained. In the figure, MC is the central control device, SC ₁ , SC ₂ . . . SC _o is the transmission line L The local controllers SC ₁ to _{SC o} are respectively connected to the central controller MC via
corresponds to, for example, a school classroom. Then, the local controllers SC ₁ to _{SC o} are given target values for each time period by a program from the central controller MC.
The temperature is controlled by time-proportional operation.

[Problem to be solved by the invention]

However, in the past, when the central controller MC calculates the optimal startup time for each air conditioning system and starts the system based on this, power limitations are expected in the precooling time due to a design that does not allow for a large margin. In some cases, the room temperature of each air conditioning system did not reach a predetermined temperature at a predetermined time.

[Purpose of the invention]

In order to compensate for this predicted temperature difference, the present invention
This system uses a predetermined calculation to control the startup time to be earlier, thereby achieving both power restriction and room comfort. The purpose of the present invention is to provide an optimal startup control method when there is a limit to the power consumption when starting up an air conditioning system before the specified time.

[Means to solve the problem]

The present invention has been made to achieve such an object, and it checks whether the average power demand of one period of time proportional operation of the entire air conditioning system during precooling is equal to or greater than a predetermined value, and detects whether the average power demand exceeds a predetermined value. In this case, a power consumption limit signal is sent to each local control device in response to the excess amount, and a start time signal is sent to extend the precooling heat time at the same rate as the reduction rate of power consumption corresponding to the excess amount. Temperature control is performed based on a power consumption limit signal and a start time signal.

〔Example〕

Hereinafter, the optimal activation control method for an air conditioning system according to the present invention will be described in detail.

First, before entering into a specific explanation of the present invention, a method (calculation formula) for determining the optimum startup time for pre-cooling heat will be briefly explained. That is, it is called a learning control method, and the optimal startup time is determined based on a calculation formula that takes actual measurement results into consideration. The calculation formula is shown below.

First, in the case of heating Next, in the case of cooling Here, T _S : Maximum preheating (precooling) time [Hr], e.g. 120 minutes T _D : Optimal startup delay time [Hr] θ _SPR : Target set temperature [℃] θ _R : Room temperature at startup [℃] Λ K ₁ : Predicted room temperature gain when starting heating [℃/Hr] Λ K ₂ : Predicted room temperature gain when starting cooling [℃/Hr] β: Compensation coefficient (depends on whether or not it was started the previous day) Coefficient β is used for compensation after holidays. You don't have to use it if you don't.

In this way, the optimal startup time is calculated by setting the maximum precooling heat time and determining how late the system should start, and this is written into the time program.

Here, the learning control method refers to the above (1) and (2).
It is so called because it is controlled by adding the actual measurement results from the previous day to the predicted room temperature gains Λ K ₁ and Λ K ₂ at the time of starting heating and cooling in the equations. The calculation formula for this predicted room temperature gain is performed as follows.

Λ K (i+1)=αΛ K (i)+(1−α)K(i) ………(3) However, Λ K (i+1): Predicted room temperature gain α on day (i+1): Learning coefficient (0 ≦α≦1) Λ K (i): Predicted room temperature gain on day i K(i): Actual room temperature gain on day i Here, α is determined empirically, as it is called a learning coefficient. It is a constant.

Now, if we give the predicted room temperature gain (amount of temperature change per hour) on the first day, the predicted room temperature gain on the second day is calculated from the actual room temperature gain on the first day using equation (3) above. given in a manner that takes into consideration. Then, from the third day onwards, it is similarly given by the above equation (3).

In this way, the predicted room temperature gain for the current day is determined, and this is substituted into the above equations (1) and (2) to calculate the startup start time.

According to the optimal startup control method of the present invention, which will be explained below, the time determined by the above equations (1) and (2) is
T _S - T _D is lengthened by the ratio of the power demand/limited power of the entire air conditioning system, and conversely, the off time of the time proportional operation is forced to be inserted by this ratio.

FIG. 2 is an explanatory diagram showing the aspect of this time-proportional operation, in which a shows the case when there is no power restriction, and b shows the case when there is a power limit. In Figure 2a, (a) "on" indicates a large deviation during the pre-cooling period, (b) P ₁ and P ₂ indicate each period, and (c) indicates "on" according to the deviation. It shows the manner in which the ratio of off-times changes. Also, in Figure 2b,
st indicates the precooling start time, which is advanced by this amount as shown in (d). P ₃ and P ₄ indicate each period, and (e) indicates a mode in which it is forcibly turned off.

Now, it can be considered that the air conditioning system issues a request to start pre-cooling heat so that each air-conditioned object (room) reaches a different predetermined temperature at a different time, so (1), (2) ) is calculated for each chamber.

As shown in FIG. 3, when time t ₀ elapses, the calculations of equations (1) and (2) above are started. Now, A, B,
Assume that the time program determines that four rooms, C and D, are to be used. In Figure 3,
(F) indicates the precooling heat start time of each room (a), (b), (c), and (d), and Ta in (a) is Ta=T _sa −T _Da , Wa (Watt),
Tb in (b) is Tb=T _sb −T _Db , Wb (watts), Tc in (c)
is Tc=T _sc −T _Dc , Wc (Watt), Td of (d) is Td=
T _sd −T _Dd , Wd (watts) is shown.

However, it is conceivable that the power used in each room is different, and the precooling heat time is also conceivable to be different.

For example, as in the example shown in Figure 3, A shown in (a)
The electricity used in the room is Wa and the pre-cooling heat time is Ta.
becomes.

Here, if the times during which these chambers A to D perform the precooling operation overlap, the maximum power demand will be the sum of these power demands.

The basic electricity rate is determined by the maximum power demand, so the contract power should be designed without giving too much margin, and the maximum power consumption should be controlled within the contracted power amount in order to reduce the basic charge. is a good idea for consumers.

In other words, in conventional air conditioning systems, the power used is controlled so that the power consumption does not exceed the contracted power amount, which is set low in order to save on basic charges. This resulted in the problem that comfort could not be ensured.

The present invention realizes an optimal startup control method for an air conditioning system that can achieve both such requirements and ensuring comfort. The central control unit MC issues a command to cut power consumption at a certain rate, and also advances the precooling heat start time.

In other words, the activation time for pre-cooling heat is determined by the central controller MC using a predetermined calculation formula (formulas (1) and (2) above), and during the pre-cooling heat, the entire air conditioning system operates in a time-proportional manner. The central controller MC checks whether the average demand power is greater than a predetermined (limit) value, and if it exceeds, the central controller MC controls each local controller according to the amount (ratio) of the excess.
Sends a power consumption limit signal to SC ₁ to _{SC o} , and
The local controller SC 1 sends a start time signal that lengthens the precooling time by the same rate as the power consumption reduction rate corresponding to the above-mentioned overage amount at the startup start time determined by the above-mentioned equations (1) and ( ₂ ). ~SC _o performs temperature control based on this power consumption limit signal and start time signal. That is, at time t ₀ shown in FIG. 3, since the chambers scheduled to be used are known in advance from the time program, the power consumption during precooling can be calculated assuming that all the scheduled chambers are used. The average power demand for one period of time-proportional operation can be determined from this power consumption, and by determining whether this average power demand is equal to or greater than a predetermined value, the above-mentioned optimal startup control method is applied. Become something. If such an optimal start-up control method is not applied, the power will be exceeded during pre-cooling, resulting in power restriction and the room temperature not reaching the predetermined value at the predetermined time.

Furthermore, to explain this in detail, when a x% power cut signal is given on the central controller MC side, each local controller SC ₁ to _{SC o} performs a time proportional operation in response to the command signal. The temperature is controlled by forcibly adding x% off time to the cycle.

Instead, the precooling heat time starts from T time (T
TXx)=(1+x)T time, and the precooling heat time becomes longer.

In this manner, when the output is limited during the pre-cooling period, the optimum startup time is advanced by calculation so that each room temperature reaches a predetermined temperature at a predetermined time.

Here, from an instantaneous point of view, the maximum power consumption has time to exceed the contracted power, but if the maximum amount of average power consumption is viewed in one period of time-proportional operation, it does not exceed the contract power, so there is no problem.

That is, as shown in FIG. 4, before time _t1 , each chamber is activated ta, tb, tc, and td hours earlier, and
Time-proportional control is also performed during the pre-cooling period, so
The average power demand does not exceed a predetermined value.

In this example, the optimal start-up control method was applied to an air conditioning system that performs time-proportional operation after time _t1 , but of course, it is applicable to an air conditioning system that does not perform time-proportional operation for temperature control after time _t1 . It may also be applied to

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, it is possible to achieve both power restriction that satisfies the requirements that are advantageous for consumers and ensuring room comfort, so the practical effects are extremely high. It's large.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of a system of a central control device and a local control device to which the optimal start-up control method for an air conditioning system according to the present invention is applied;
FIG. 3, and FIG. 4 are operation explanatory diagrams for explaining the time proportional operation and precooling heat operation of the present invention. MC...Central control unit, L...Transmission line,
SC ₁ ~SC _o ...Local control device.

Claims (1)

[Claims] 1. Consisting of a central control device and a plurality of local control devices connected to this central control device via transmission lines, each local control device receives the target for each time period from the central control device by a program. In an air conditioning system, the temperature is controlled based on a given value, and the startup time for precooling heat is determined by the central controller using the following predetermined calculation formula. The central control device checks whether the average demand power of the cycle is equal to or greater than a predetermined value set in advance, and if it exceeds the predetermined value,
In response to the excess amount, the central control device sends a power consumption limit signal to each of the local control devices, and also sends a start time signal to extend the precooling heat time at the same rate as the reduction rate of power consumption corresponding to the excess amount. and each local control device performs temperature control based on the power consumption limit signal and the start time signal. Here, T _S : Maximum preheating (pre-cooling) time [Hr] T _D : Optimal startup delay time [Hr] θ _SPR : Target set temperature [℃] θ _R : Room temperature at startup [℃] Λ K ₁ : At heating startup Predicted room temperature gain [℃/Hr] Λ K ₂ : Predicted room temperature gain at cooling start [℃/Hr]