JPH0512625B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides a central heat source that circulates and supplies a heat medium fluid whose temperature is adjusted to a target temperature to each of a plurality of terminal air conditioners; The present invention relates to a central air conditioner comprising: a load determining means for determining the air conditioning load state of the load determining means; and a control means for automatically changing the target temperature to a load canceling side and a side opposite to the load canceling side based on determination information of the load determining unit.

[Conventional technology]

Conventionally, in such a central air conditioner, the following control form has been adopted for changing the target temperature of the heat medium fluid based on the judgment information of the load judgment means.

That is, regarding the change to the load relief side, when the load determination means determines that at least one of the terminal air conditioners is in an overload state, the target temperature is simply changed by a predetermined temperature to the load relief side. It had a repeating structure. By the way, regarding the change to the side opposite to the load relief side, the target temperature is changed to the side opposite to the load relief side by a predetermined temperature, with respect to the judgment of the load judgment means that all terminal air conditioners are in a non-overload state. The configuration was such that the changes were simply repeated (see, for example, Japanese Patent Laid-Open No. 127738/1983).

[Problem to be solved by the invention]

However, in the above-mentioned conventional central air conditioner, when changing to the load cancellation side, when the load determination means determines that at least one of the terminal air conditioners is in an overload state, the load is canceled by a predetermined temperature by changing the target temperature. Because the process of changing the temperature to the other side is simply repeated, even if the target temperature is only changed up to a certain stage,
There are situations in which a terminal air conditioner that has been determined to be in an overload condition returns to a non-overload condition after a while due to a delay in air conditioning, or a situation in which the terminal air conditioner is determined to be in an overload condition is sufficiently restored to a non-overload condition after a while, or it is in a situation where the terminal air conditioner is determined to be in an overload condition due to a temporary disturbance. However, even though the current target temperature would be sufficient to return to the non-overload state, the target temperature may be changed more than necessary to the load-relieving side prematurely. As a result, there was a problem that the desired goal of energy saving could not be achieved sufficiently, and there was also a problem that the stability of air conditioning was impaired due to frequent target temperature changes.

The present invention has been made in view of the above-mentioned conventional circumstances, and its purpose is to provide a central air conditioner with a rational improvement in the target temperature control form of the heat transfer fluid, while sufficiently maintaining the air conditioning function. The purpose of this invention is to prevent prematurely changing the target temperature to a load-reducing side more than necessary, thereby achieving even higher energy savings.

[Means to solve the problem]

The characteristic configuration of the central air conditioner according to the present invention includes a central heat source that circulates and supplies a heat medium fluid whose temperature is adjusted to a target temperature to each of a plurality of terminal air conditioners, and a central heat source that determines the air conditioning load state of each of the terminal air conditioners. In a configuration comprising: a load determining means; and a control means for automatically changing the target temperature to a load canceling side and a side opposite to the load canceling side based on determination information of the load determining means, Among the target temperature changes based on the determination information, at least for the change to the side of load cancellation, the determination by the load determination means that at least one of the terminal air conditioners is in an overload state continues for a predetermined period of time. when the target temperature is changed by a predetermined temperature to the load canceling side, the process is repeated at the predetermined time intervals;
Its actions and effects are as follows.

[Effect]

In the above characteristic configuration, the effect of changing the target temperature of the heat transfer fluid is not immediately reflected in the air conditioning control, and it is necessary to avoid unnecessary control caused by temporary disturbances. Considering this, even if the target temperature is repeatedly changed to the load-relieving side by a predetermined temperature, it is necessary to do so at predetermined time intervals, and each time, at least one terminal air conditioner is in an overload state. When the determination continues for the above-mentioned predetermined time, the target temperature is changed to the load-relieving side by a predetermined temperature for the first time, and then the next time the target temperature is changed, thereby confirming the effect of changing the target temperature to the load-relieving side. By providing a waiting time for this and by preventing an overload state caused by a temporary disturbance from being judged as an overload, it is possible to accurately determine which terminal air conditioner is in an overload state.

Therefore, it is possible to change the heating medium fluid temperature by a predetermined temperature to the load canceling side only when the overload condition cannot be canceled with the current heating medium fluid temperature, thereby eliminating the load. If the target temperature is changed to a certain level, or if the current target temperature is maintained and the non-overload state is fully restored after a while, the target temperature is applied more than necessary. It is possible to prevent a change to the cancellation side.

〔Effect of the invention〕

As a result, although the air conditioning function was maintained by repeatedly changing the target temperature to the load relief side, unlike the conventional device mentioned above, the target temperature was changed prematurely to the load relief side more than necessary. Since this can be reliably prevented, it has become possible to achieve even higher levels of energy savings. Furthermore, frequent changes in the target temperature can be suppressed, and the stability of air conditioning can also be improved.

〔Example〕

Hereinafter, specific embodiments of the present invention will be described based on the drawings.

Figure 1 shows the overall schematic configuration of a central heating system, in which a plurality of air-conditioned rooms R ₁ ... _R A plurality of terminal air conditioners 3 respectively installed in... (fan convector)
However, header H, H and box stock BC...
are connected in parallel to each other via.

In the central heat source 1, 4 is a fuel gas supply path, 5 is a Bunsen type main burner connected to the tip thereof, 6 is a pilot burner, 7 is a spark igniter for the pilot burner 6, and 8 is for pilot burner flame detection. Thermocouple, V ₀ is a manual main valve, SV is an electromagnetic safety shutoff valve, MV is an electromagnetic main valve, 9 is a Finch-Ube heat exchanger for heating medium fluid, 10 is this heat exchanger TH ₀ is a pump for circulating heat medium fluid installed on the inlet side of heat exchanger 9;
1 is cistern.

Moreover, in the terminal air conditioner 3..., 12...
is an air conditioning fan, 13 is a Finch-Hube type air conditioning heat exchanger, and V ₃ is the air conditioning heat exchanger 13...
TH ₁ ... TH _o are the thermometers (load judgment means) for detecting the indoor temperature of each air-conditioned room R ₁ ... R _o , and SW ₁ ... SW _o are the electromagnetic flow path opening/closing valves for each terminal air conditioner 3... It is an ON/OFF switch. In addition, the indoor temperature detection thermometer TH ₁ ... TH _o is as follows:
Each of them is configured to remain in the ON state until the indoor temperature of the rooms R ₁ ... R _o reaches the set temperature (this can be set arbitrarily), and then to become the OFF state. Therefore, the above
Only when the ON/OFF switch SW ₁ ...SW _o is turned on (ON) and the indoor temperature of the room _R1 ...R _o is below the set temperature, the on-off valve V3 is opened and the above-mentioned on-off valve _V3 is opened. The fan 12 will be activated.

C is an automatic control device mainly composed of a CPU, which includes an automatic ignition control device that opens the safety shut-off valve SV and the main valve MV and operates the igniter 7 in response to a starting operation, and the thermocouple 8. automatic safety control that closes the safety shut-off valve SV upon detection of pilot burner flame extinguishing (both of the above automatic controls are well known, so their explanation will be omitted); and the thermostat TH for detecting the heat medium fluid outlet temperature ₀ and the temperature detection results by the above-mentioned indoor temperature detection thermometers TH ₁ ...TH _o ,
ON/OFF switch for each terminal air conditioner 3...
Based on the state detection results of _SW1 ... _SWo , the heat medium fluid outlet temperature θ is automatically controlled as follows.

That is, the automatic control device basically determines the PID based on the comparison between the set control target temperature θ _s of the heat medium fluid and the detected outlet temperature θ by the heat medium fluid outlet temperature detection thermometer TH ₀ . The opening and closing of the main valve MV is controlled so as to maintain the heat medium fluid outlet temperature θ near the control target temperature θ _s through control, but in the method of the present invention, the control target temperature θ s The settings are automatically performed using the following algorithm. That is, (i) at the start and when the number of air conditioners 3 in use increases, the control target temperature θs is set to a predetermined upper limit temperature θmax (for example, 80° C.).

(ii) When it is detected that the indoor temperatures of all the rooms being air-conditioned using the air conditioner have reached the set temperature, the control target temperature θs is immediately lowered by a predetermined temperature Δθ (for example, 5° C.).

(iii) After the control in (ii) above, a predetermined period of time (e.g.
15 minutes), if even one of the detected indoor temperatures is below the set temperature, the control target temperature θs is changed to the predetermined temperature Δθ.
(e.g. 5°C).

FIG. 2 shows an example of a flowchart of a control subroutine for realizing automatic control using the above algorithm.

That is, in the step after START, the arithmetic integer parameter i is reset (i=1). Before entering this control subroutine, the following various parameters TPi,
SWi ₀ is reset to 1 and 0 respectively, and
The timer has also been reset to its initial state. Here, TPi is a parameter that indicates that the indoor temperature has not reached the set temperature when it is 1, and that it has reached the set temperature when it is 0, and STi ₀ and SWi are the respective ON and OFF switches SW ₁ ... SW This parameter represents the state of _o , with 1 representing ON and 0 representing OFF.

In the step, it is checked whether SWi is ON or OFF, and if it is OFF, the step moves to the backward step routine in which TPi is set to 0, and if it is ON, the process moves to the step.

In the step, the previous state of SWi is checked, and if it is _OFF0 , it goes to the step and turns ON.
If it is 1, proceed to step.

In the step, it is determined that the air conditioner 3 has been newly turned on, so the control target temperature θs is set to the predetermined maximum temperature θmax, and in the next step, the parameter SWi ₀ is set to 1 and the timer is reset. Return.

At the step, there is a thermometer THi for indoor temperature detection.
The status of is checked, and if OFF is 0, TPi is 0
If it is set to ON1, the process moves to the step routine.

In the step routine, the parameter i is incremented in steps, and in the next step it is checked whether the parameter i exceeds the total number n of air conditioners 3 . If i≦n, return to step; if i>n, return.

In step, the total of n TPi is calculated, and if the value is 0, it is determined that all indoor temperatures have reached the set temperature, and the process moves to the target temperature reduction routine, and if the value is 0. If not, proceed to step.

In step, it is checked whether a predetermined period of time (for example, 15 minutes) has elapsed, and if it has elapsed, the process moves to the target temperature increase routine, and if it has not elapsed, it moves to the stepping routine.

The target temperature reduction routine basically changes the control target temperature θs to a predetermined temperature △ as shown in steps.
θ (for example, 5℃), but as shown by step Lower limit temperature θmin
It is set to .

On the other hand, the target temperature increase routine basically raises the control target temperature θs by a predetermined temperature △θ (for example, 5°C), as shown in steps. When θs becomes higher than the upper limit temperature θmax (for example, 80° C.), the upper limit temperature θmax is uniformly set.

After this, the timer is reset in the step,
Step ~〓〓 is the ON/OFF switch SW ₁ ...SW _o
Check whether is ON or OFF,
If ON, TPi is set to 1 and RETURN
do.

In addition, in the above embodiment, a method of automatically changing and controlling the temperature control target temperature θs for the heat medium fluid of the heat source 1 is described based on whether or not all the thermos for detecting the indoor temperature of the room being air-conditioned are turned off. In addition to this, the thermometer for each room temperature detection is turned on,
The OFF time ratio (the ratio of time during a predetermined period of time when the load determination means TH ₁ and TH _o determine that there is no load) (tOFF/tON + tOFF) is calculated, and the thermometer for detecting the indoor temperature of the room being air-conditioned is calculated. Automatic change control of the control target temperature θs is performed based on the time ratio, such as reducing the control target temperature θs by a predetermined temperature Δθ when the time ratios of all exceed a predetermined value (for example, 80%). You may do so.

Further, in the above embodiments, the method of the present invention was applied to a heating system, but it goes without saying that it can also be applied to a cooling system or an air-conditioning/heating system.

[Brief explanation of the drawing]

The drawings show an embodiment of the central air conditioner according to the present invention, with FIG. 1 being a general schematic diagram and FIG. 2 being a control flowchart. 1...Heat source, 3...Terminal air conditioner, θs...Target temperature,
Δθ...predetermined temperature, C...control means, TH...load determination means.

Claims (1)

[Scope of Claims] 1. Determine the air conditioning load state of the central heat source 1 that circulates and supplies heat medium fluid whose temperature is adjusted to a target temperature θs to each of the plurality of terminal air conditioners 3, and each of the terminal air conditioners 3. A central air conditioner comprising a load determining means TH, and a control means C for automatically changing the target temperature θs to a load canceling side and a side opposite to the load canceling side based on the determination information of the load determining unit TH, the central air conditioner comprising: The control means C controls the load when at least one of the terminal air conditioners 3 is in an overload state, when changing the target temperature based on the judgment information of the load judgment means TH, at least to the load cancellation side. When the determination by the determination means TH continues for a predetermined period of time, the target temperature θs is changed to a predetermined temperature △
A central air conditioner configured to repeat changing the load by θ to the load canceling side at predetermined time intervals. 2 When changing the target temperature of the control means C to the side opposite to the load cancellation side based on the judgment information of the load judgment means TH, all of the terminal air conditioners 3 are set to non-operation by the load judgment means TH. When it is determined that there is an overload state, the target temperature θs
The central air conditioner according to claim 1, wherein the central air conditioner is configured to repeatedly change the temperature by a predetermined temperature Δθ to the side opposite to the load cancellation side. 3. When changing the target temperature to the side opposite to the load cancellation side based on the judgment information of the load judgment means TH, the control means C is controlled in a non-overload state by the load judgment means TH during a predetermined period of time. When the ratio of the time when it is determined that the condition is equal to or higher than a predetermined value for all of the terminal air conditioners 3, the target temperature θs is changed by a predetermined temperature Δθ to the side opposite to the load cancellation side for each predetermined time. The central air conditioner according to claim 1, wherein the central air conditioner has a structure that repeats the following.