JPH0532658B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides an air conditioner equipped with an air conditioning heat exchanger and a fan that blows air onto the heat exchanger and then blows the air out of the device. The present invention relates to a heat medium circulation type air conditioner provided with a control means for controlling a heat source so that the temperature of a heat medium fluid circulated through a heat exchanger of the air conditioner reaches a target temperature.

[Conventional technology]

In conventional air conditioners (here, we will use heating devices as an example, but from this explanation you can easily infer cooling devices as well), the number of revolutions of the fan is generally constant. (Air volume is constant), even if the heat medium fluid is within the temperature range that can be heated, when the temperature of the heat medium is relatively low, the hot air blown by the fan will feel cold. The basic drawback is that when the temperature of the heat medium is relatively high, the hot air blown by the fan gives the user a feeling of overheating, which results in relatively large unevenness in the feeling of being heated.

In addition, some devices are configured so that the air blown by the fan can be arbitrarily switched between strong (large air volume) and weak (low air volume) by manual operation, but the operation is cumbersome and inconvenient. Not only is this system lacking in functionality, but it only takes into account the switching of the strength of the blowing air, and it is of little use in solving the above-mentioned drawbacks. This is because, from a human sense of operation,
If you have the fan set to low and you feel a cold breeze, you should naturally switch the fan to strong, and conversely, if you have the fan set to high and feel a feeling of overheating, you should naturally switch the fan back to low. I will do it. In this case, unless the temperature of the heat transfer fluid is controlled in some way, the above-mentioned drawbacks will be exacerbated.

On the other hand, in order to prevent cold air from blowing out especially at the start of heating, temperature switches such as thermal reed switches or bimetal switches that turn on and off depending on the temperature of the heat medium fluid that is circulated and supplied to the air conditioning heat exchanger are used. It is also known that the fan is installed in the drive circuit of the wind blowing fan so that the fan is not operated when the temperature of the heat transfer fluid is below a predetermined value. For example, the operating characteristic of the temperature switch is that the temperature of the heat medium fluid must drop until the ambient temperature near the heat exchanger reaches about 35°C.
Since there is a relatively large hysteresis in which the fan does not turn off and does not turn on until the ambient temperature rises to about 49℃, the fan cannot be turned on and off accurately at the desired heating fluid temperature.
The OFF control cannot be performed, and the fan does not operate even though the heating medium temperature has reached a sufficient temperature for heating, or the heating medium temperature has dropped and cold air is now coming out. There are drawbacks such as the fan not stopping. Therefore, even with a structure that prevents cold air from blowing out,
As long as the amount of air blown by the fan is constant, the above basic drawbacks cannot be overcome.

[Problem to be solved by the invention]

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide uneven heating sensation (cold air The aim is to eliminate as much as possible the feeling of overheating and feeling of overheating.

[Means to accomplish the task]

The characteristic configuration of the heat medium circulation type air conditioner according to the present invention is that air volume control means for controlling the air volume blown by the fan is provided, and the control means is set to a load canceling side as the air conditioning load increases, such that the target temperature of the heat medium fluid increases. and, based on the changed target temperature, change the setting so that the target air volume blown by the fan increases as the air conditioning load increases, and the air volume control means The present invention is configured to control the amount of air blown out by the fan so that the amount of air blown out is a target air amount set by the means.

[Action and effect]

According to the above characteristic configuration, the target temperature of the heat medium fluid generated by the heat source is set to be changed to the side where the air conditioning load increases as the air conditioning load increases. Since the temperature of the fluid can be automatically controlled to be kept as low as possible without interfering with comfortable air conditioning performance, depending on the air conditioning load, energy loss due to heat radiation from piping etc. can be extremely reduced. In addition, the temperature of the heat transfer fluid that returns to the heat source can be kept as low as possible, which improves the efficiency of the heat source, making it possible to achieve significant energy savings while maintaining comfortable air conditioning performance as a whole. Basic effects can be obtained. Furthermore, based on the target temperature of the heat transfer fluid that has been automatically changed as described above, the setting is changed so that the target blowout air volume by the fan increases as the air conditioning load increases, and the circulating supply is supplied to the heat exchanger. The higher the temperature of the heating medium fluid is, the higher the airflow volume should be, and the lower the temperature, the lower the airflow volume should be.
(In the case of air conditioning, the opposite is true) Since the fans are automatically controlled, the amount of heat held per unit air volume tends to be equalized even if the heat medium fluid temperature changes.
In other words, the temperature of the blowing air is almost constant regardless of the temperature of the heating medium fluid, and therefore, unevenness in the feeling of being heated, such as the feeling of cold air or overheating caused by temperature changes of the heating medium fluid, can be minimized. In other words, during heating, there is a feeling of cold air when the heating medium temperature is relatively low, and a feeling of overheating when it is relatively high, and during cooling, there is a feeling of warm air when the heating medium temperature is relatively high, and a feeling of overheating when the heating medium temperature is relatively high. The feeling of overcooling at low temperatures is greatly reduced compared to conventional systems, making it possible to always enjoy extremely comfortable air conditioning.

In addition, since the above effects can be obtained, the temperature difference between the heating medium fluid and the outside air temperature can be made as small as possible, that is, in the case of heating, the temperature of the heating medium fluid can be lowered, and also in the case of cooling. In this case, the comfort of air conditioning can be ensured even if the temperature of the heating medium fluid is increased during operation, so from this point of view as well, the heat dissipation loss due to the transport of the heating medium fluid can be kept as small as possible. Further energy saving effects can be achieved.

Furthermore, according to the above configuration, it is possible to easily prevent cold air from blowing out (in the case of heating) when air conditioning is started, so there is an advantage that a special mechanism for preventing cold air from blowing out is not required.

It is also possible to proportionally control the amount of air blown out by the fan based on the temperature of the heat transfer fluid itself, but in that case, the amount of air blown out by the fan may fluctuate even in response to slight fluctuations in the temperature of the heat transfer fluid. However, in the present invention, control is performed using the target temperature of the heat medium fluid, which is an indirect parameter, rather than using the direct parameter of the heat medium fluid temperature itself. This has the advantage that minute fluctuations in the heat medium fluid temperature are not reflected in the air volume blown out by the fan, allowing stable control to be performed.

〔Example〕

Hereinafter, specific embodiments to which the present invention is applied 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 (Ri, i = ₁ A plurality of terminal air conditioners (fan convectors) (3i, i= ₁ to n) respectively arranged in the air conditioners H, H, H and box stocks BC are connected in parallel to each other via headers H, H and box stocks BC.

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 a thermoelectric wire for detecting the pilot burner flame. In contrast, 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 a heat medium fluid, and 10 is this heat exchanger 9. _TH0 is a temperature sensor installed on the outlet side of the heat exchanger 9 for detecting the heat medium fluid outlet temperature θ, and 11 is a cistern.

In addition, the terminal air conditioner (3i, i= ₁ to n)
, 12... is a Finch-Hube air conditioning heat exchanger, _V3 ... is an electromagnetic flow path opening/closing valve for the air conditioning heat exchanger 12..., and 13... is a blowing air to the heat exchanger 12... An air conditioning fan for blowing the air into the room, (THi, i= ₁ ~
n) is a thermometer for detecting the indoor temperature of each air-conditioned room (Ri, i= ₁ to n), and (SWi, i= ₁ to n) is a thermostat for each terminal air conditioner (3i, i= ₁ to n).・ON/OFF switch for stopping, 14... is the power supply for the said fan, 15... is the said fan 13
This is a rotation speed control device for the fan 13, which serves as an air volume control means for controlling the air volume blown out. In addition, the indoor temperature detection thermometer (THi,
i = ₁ to n) are in the ON state until they reach the room temperature of the room (Ri, i = ₁ to n) (this can be set arbitrarily), and then they are in the OFF state. Therefore, when the ON/OFF switch (SWi, i= ₁ to n) is turned on (ON), the room (Ri, i= ₁ to n) is turned on. Only when the temperature is below the set temperature, the on-off valve _V3 is closed and the fan 13 is operated.

C is an automatic control device as a control means whose main component is a CPU;
Automatic ignition control that opens the igniter and operates the igniter 7; Automatic safety control that closes the safety shutoff valve SV when the thermocouple 8 detects extinguishment of the pilot burner flame (both of the above automatic controls are well known, so ), the thermometer for detecting the heat medium fluid outlet temperature TH ₀ and the thermometer for detecting the indoor temperature (THi, i= ₁ to
n) temperature detection results and the ON/OFF switch of each terminal air conditioner 3 (SWi, i = ₁ to n)
Based on the state detection results of the heating medium fluid outlet temperature θ and the rotation speed α of the fans 13 as follows,
(Blowout air volume) is automatically controlled.

That is, the automatic control device C basically performs PID control based on a comparison between the set control target temperature θs of the heat medium fluid and the outlet temperature θ detected by the thermometer THa for detecting the heat medium fluid outlet temperature. 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 θs, but in this embodiment, the setting of the control target temperature θs is automatically performed as follows.

That is, the basic method of automatic control is to set the target temperature θs of the circulating heat medium according to the continuous operating time of one air conditioner 3i selected from the air conditioners (3i, i= ₁ to n). The setting is automatically changed so that the next continuous operation time of the selected air conditioner 3i approaches a predetermined set time _T0 .

As one of the specific means for realizing this basic method, the following algorithmic procedure is adopted.

(i) At the start, the control target temperature θs is set to a predetermined upper limit temperature θmax (for example, 80° C.).

(ii) Among the air conditioners that are activated, the one with the largest air conditioning load (3i) will be selected based on city regulations.

(iii) Regarding the selected standard air conditioner 3i,
The operation duration T of the reference air conditioner 3i is determined from the ON state duration time of the indoor temperature detection thermometer THi.

(iv) Then, depending on the operation duration T of the reference air conditioner 3i, set the target temperature θs of the circulating heat medium,
The next operation duration of the reference air conditioner 3i is automatically set to approach a predetermined appropriate time T ₀ , and the rotation speed of the fan 13 is set according to the automatically set target temperature θs. The target rotational speed αs (target air volume) given to the control device 15 is also automatically set. That is, as shown in Fig. 2, the operating duration T of the reference air conditioner 3i is equal to the set time.
If it is less than or equal to T ₀ , then θs becomes θ _{0 -θ -3 (} θmin) and αs becomes α ₀ -
When α1 _-3 (αmin), <2> T _-3 ≦ T < T _-2 , θs becomes θ ₀ - _{θ -2} , and αs becomes α ₀ - α _-2 <3> T _-2 When ≦T<T _-1 , θs becomes θ ₀ -θ _-1 and αs becomes α ₀ -α _-1 . When <4> T _-1 ≦T≦T ₀ , θs becomes θ ₀ ( Based on the idea that emphasis is placed on the comfort of heating, if the operation duration _T exceeds the set time _T0 , Without waiting for the reference air conditioner 3i to stop operating, <5> When T>T ₀ , θs becomes θ ₀ + θ ₁ and αs becomes α ₀ + α ₁ , <6> When T>T ₁ , θs becomes θ ₀ +θ ₂ , and αs becomes α ₀ +α _2. <7> When T>T ₂ , θs becomes θ ₀ +θ ₃ (θmax) Then, the target temperature θs of the heat transfer fluid and the target rotation speed αs that determines the airflow volume of the fan are forcibly and automatically changed in multiple stages, such as αs to α ₀ + α ₃ (αmax). Let it happen. In addition, if the minimum rotation speed (αmin) is set to 0,
It is possible to easily prevent cold air from blowing out at the start of heating.

FIG. 3 shows an example of a flowchart of a control subroutine for performing automatic control using the above algorithm.

That is, after the various parameters for calculation are initialized in the post-START step, one air conditioner 3i is selected as a reference for control in the step. In this example, each air-conditioned room (Ri,
The order of the air conditioning load is determined in consideration of the size and position of the air conditioners (i= ₁ to n), and a table is created and activated. In other words, the air conditioner 3 whose ON/OFF switch (SWi, i= ₁ to n) is turned on
From among i, the one with the largest air conditioning load is selected.

Next, in step, the target temperature θs of the heating medium
is initially set to the maximum temperature θmax, and in step, a timer is started to measure the ON state duration time of the indoor temperature detection thermometer THi, that is, the operation duration time T of the air conditioner 3i.

Then, in a step, it is determined whether the thermostat THi for indoor temperature detection is switched from an ON state to an OFF state, and in a subsequent step, the operation duration T is calculated.

Next, in step, the target temperature .theta.s of the heating medium and the target rotation speed .alpha.s of the fan are changed in accordance with the operation duration T by the algorithms <1> to <7> described above.

Then reset the timer in step,
The thermometer THi for indoor temperature detection is activated again in the step.
Wait until the thermostat THi turns ON.
If the switch is switched to the ON state, the process returns to the above-mentioned step.

In addition, in the above embodiment, when selecting one air conditioner 3i as a reference for control, the one with the largest air conditioning load among the activated air conditioners (3i, i= ₁ to n) is selected. However, it is not necessary to do so; for example, one with an average air conditioning load may be selected.

In addition, in the above embodiment, the target temperature θs of the heating medium and the target rotation speed αs of the fan are automatically changed in multiple stages (7 stages), but for example, the setting is changed automatically in multiple stages (7 stages). Alternatively, control may be performed using other functions.

Furthermore, in the above embodiments, the present invention was applied to a heating system, but it is of course applicable to a cooling system or an air-conditioning/heating system.

[Brief explanation of drawings]

The drawings show an embodiment of a central air conditioning system to which the present invention is applied, in which Fig. 1 is a schematic diagram of the overall system configuration, Fig. 2 is a graph for explaining the control algorithm, and Fig. 3 is its control flow. It's a chat. 1...Heat source, 3i...Air conditioner, 12...Air conditioning heat exchanger, 13...Fan, 15...Air volume control means, C...Control means, Ri...Air conditioned room, θs...
...Target temperature.

Claims (1)

[Scope of Claims] 1. An air conditioner 3i including an air conditioning heat exchanger 12 and a fan 13 that blows air onto it and then blows the air out of the device is arranged in an air conditioned room Ri, and the air conditioner A heat medium circulation type air conditioner is provided with a control means C for controlling the heat source 1 so that the temperature of the heat medium fluid circulated in the heat exchanger 12 of 3i reaches the target temperature θ _s , An air volume control means 15 for controlling the air volume is provided, and the control means C changes the setting of the target temperature θ _s of the heating medium fluid to the side where the air conditioning load increases as the air conditioning load increases, and the set target temperature θ _s , the setting is changed so that the target air volume blown by the fan 13 is increased as the air conditioning load increases, and the air volume control means 15 is set to the target air volume set in the control means C. So that the fan 1
3. A heat medium circulation air conditioner configured to control the amount of air blown out.