JP3516883B2 - Fan coil air conditioning control system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention controls the air conditioning capacity of a fan coil by adjusting the opening of an automatic control valve provided on a supply passage for supplying water (cold water or hot water) from a heat source to a fan coil. The present invention relates to an air conditioning control system.

[0002]

2. Description of the Related Art In designing a fan coil air-conditioning system, a flow rate value at which the exchange heat quantity in the coil of the fan coil is not saturated, that is, a flow quantity value at which the exchange heat quantity does not increase even if cold water or hot water is further flowed, is used as a design flow rate. It is decided in advance before operating the equipment. When the design flow rate is flowed, the temperature difference between the incoming water to the fan coil and the returning water is about 5 ° C.

In fan coil air-conditioning equipment, design flow rates, water supply temperatures, and rated air volumes are shown as equipment specifications. If the operating point is close to this value, the amount of heat exchanged will not be saturated and the temperature difference will not decrease. If the difference between the return water temperature is about 5 ° C, the efficiency of the heat source equipment is also increased, so 5 ° C is often the design target.

[0004]

However, in the conventional fan coil air-conditioning equipment, the flow rate of the actually flowing water exceeds the design flow rate (overflow rate) due to the following factors (1) to (3) The temperature difference causes a situation where the design target cannot be secured. Overflow causes an increase in water transportation power, and a low temperature difference between the return water causes a decrease in efficiency of the heat source, resulting in waste of energy and increase in operating costs of equipment. The efficiency of heat exchange deteriorates due to the contamination of the inside of the coil and the fins, and the temperature difference between the return water cannot be secured. When a short circuit occurs, there is no temperature difference between the supply air and the return air, heat exchange between the coil and air is not promoted, and the temperature difference between the return water and the return water cannot be secured. When the amount of air blown by the fan is fixed at a low amount, the amount of air passing through the coil is insufficient, heat exchange between the coil and air is not promoted, and the temperature difference between the return water cannot be ensured. When the design of the air conditioning load is improper, the capacity is insufficient, the amount of heat exchanged is saturated, and the temperature difference of the return water cannot be secured. If the pipeline resistance adjustment of the entire piping system or the selection of the automatic control valve are inappropriate, an excessive flow rate may result. Heretofore, effective measures have not been taken against such overflow and low temperature difference of return water. This is because control of the thermal environment in the residential area of the building is directly linked to the comfort level and complaints of the occupant, while the problems of equipment efficiency and driving do not appear to the occupant.

The present invention has been made to solve such a problem, and an object thereof is to prevent an excess flow rate even if the temperature difference of the return water is insufficient, that is, to reduce the return water. An object of the present invention is to provide a fan coil air-conditioning control system in which a temperature difference and an excessive flow rate do not occur at the same time.

[0006]

In order to achieve such an object, the first invention (the invention according to claim 1) is the return water temperature.
When the temperature difference is smaller than the set temperature difference, the fan air volume is maximum.
If it is not a large air volume, it is controlled to increase the air volume of the fan.
However, the difference in the temperature of the return water is greater than the set temperature by more than a specified value.
If the fan air volume is not the minimum when
While controlling to reduce the air flow,
When the temperature difference is smaller than the set temperature difference, the fan air volume is the maximum
, The upper limit is the current opening of the self-regulating valve.
The opening of the automatic control valve is controlled. This
According to the invention of, when the air volume of the fan is not the maximum air volume,
If the return water temperature difference becomes smaller than the set temperature difference, the fan
The volume of airflow is increased to promote heat exchange in the coil,
The temperature difference becomes large. Return water temperature difference is more than set temperature difference
The air volume of the fan becomes larger than the specified value, and the air volume of the fan at that time is the minimum
If not, the air volume of the fan is reduced. Fan
Even if the air volume is set to the maximum air volume, the return water temperature difference is
If it becomes too small, it will be automatically adjusted with the opening at that time as the upper limit.
The opening degree of the valve is controlled. As a result, the air volume of the fan
Despite the maximum air volume, the difference between the return water temperature is the set temperature.
If it becomes smaller than the difference, the flow rate at that point will be the upper limit.
Flow rate within the range that does not exceed this upper limit.
Adjusted.

[0007]

The second invention (the invention according to claim 2) is the first invention.
In the invention, a predetermined time has passed since the fan coil was activated.
Up to the current opening of the automatic control valve until
This prohibits all opening control. From this
According to Ming, a predetermined time has passed since the fan coil was activated.
Until the elapse of time, the fan air volume is the maximum and the return water
Even if the temperature difference is smaller than the set temperature difference, the
The opening control with the current opening as the upper limit is not performed.

[0009]

[ Reference example ]

FIG. 1 is a configuration diagram showing a main part of a fan coil air conditioning control system which is a reference example before the description of the present invention . In the figure, 1 is a fan 1-1 and a coil (cooled / hot water coil) 1
-2 is a fan coil composed of 2 and 2 is a heat source,
An automatic control valve 3 is provided on a supply passage for supplying water (cold water or hot water) from the heat source 2 to the fan coil 1.

A forward water temperature sensor 5 is provided on the forward water passage 4S, and a return water temperature sensor 6 is provided on the return water passage 4R. The outlet temperature of the heat source 2 may be measured as the outgoing water temperature. Reference numeral 7 denotes an indoor temperature sensor that detects the temperature inside the room supplied with the supply air from the fan coil 1.

Reference numeral 8 denotes a control device, which is a temperature difference calculation unit 8-
1, temperature difference comparison unit 8-2, post-startup time measurement unit 8-3, limit unit 8-4, temperature PID unit 8-5, and MIN unit 8
-6 is provided. The temperature difference calculation unit 8-1 receives the return water temperature TS from the return water temperature sensor 5 and the return water temperature TR from the return water temperature sensor 6, and outputs | TS-TR | as the return water temperature difference ΔT. To do. The temperature difference comparison unit 8-2 compares the return water temperature difference ΔT from the temperature difference calculation unit 8-1 with a preset temperature difference ΔTsp (for example, ΔTsp = 5 ° C.), and compares the comparison result. Output.

The post-startup time measuring unit 8-3 measures the time after the fan coil 1 is started up (post-startup time) until the post-startup time exceeds a predetermined time (1 hour in this example). , The operation of the limit unit 8-4 is prohibited. The limit unit 8-4 uses the ΔT and Δ from the temperature difference comparison unit 8-2.
When the comparison result with Tsp is input and ΔT ≦ ΔTsp, the instruction opening θR to the automatic control valve 3 is read as the current opening, and the read current opening θR is output as the upper opening θLIM. To do.

The temperature PID section 8-5 is an indoor temperature sensor 7
From the room temperature tpv and the set room temperature tsp,
By the PID calculation, the target opening degree θT for the automatic control valve 3 such that tpv = tsp is calculated. MIN section 8-
6 receives the target opening degree θT from the temperature PID section 8-5 and the upper limit opening degree θLIM from the limit section 8-4, and outputs the smaller one as the instruction opening degree θR.

FIG. 2 shows a processing flow in the control device 8.
In the post-startup time measuring unit 8-3, when the time after the fan coil 1 is started exceeds 1 hour (step 20
1), the operation of the limit unit 8-4 is permitted.
As a result, the limit unit 8-4 has the temperature difference comparison unit 8-2.
Based on the comparison result of the return water temperature difference ΔT from the set temperature difference ΔTsp, if ΔT ≦ ΔTsp, the instruction opening degree θR to the automatic control valve 3 is read as the current opening degree,
The read current opening θR is output to the MIN unit 8-6 as the upper limit opening θLIM.

Assuming now that ΔT> ΔTsp (NO in step 202), the limit unit 8-4 has the MIN unit 8-
6, the upper limit opening θLIM is not output, and the MIN unit 8-6 outputs the target opening θT from the temperature PID unit 8-5 as the instruction opening θR. As a result, the opening degree of the automatic control valve 3 becomes θ.
R = θT is set, and the flow rate of water sent from the heat source 2 to the fan coil 1 is adjusted according to the difference between the indoor temperature tpv and the set temperature tsp (step 203).

From such a state, when the return water temperature difference ΔT becomes small and ΔT ≦ ΔTsp is satisfied (step 202).
YES), the limit unit 8-4 starts outputting the current opening θR to the MIN unit 8-6 with the upper limit opening θLIM (step 204). As a result, the target opening θT from the temperature PID unit 8-5 is θLIM in an attempt to return to ΔT> ΔTsp.
Even if it becomes larger, θR does not become larger than θLIM. If the opening θT from the temperature PID unit 8-5 becomes smaller than θLIM, θT is output as θR.

That is, when ΔT ≦ ΔTsp, the opening control (limit control) of the automatic control valve 3 is performed with the opening θR at that time as the upper limit opening θLIM. As a result, the flow rate at the time when the return water temperature difference ΔT becomes smaller than the set temperature difference ΔTsp is set as the upper limit (point P in FIG. 3), and the flow rate is adjusted within a range not exceeding this upper limit, and the return water Even if the temperature difference ΔT is insufficient, the overflow does not occur, and the low temperature difference of the return water and the overflow are prevented from occurring at the same time.

It should be noted that, since the fan coil 1 is activated,
Until the time elapses, even if the return water temperature difference ΔT is smaller than the set temperature difference ΔTsp, the current opening θR of the automatic control valve 3 is not subjected to limit control with the upper limit opening θLIM. When the fan coil 1 is started, pre-cooling / pre-heating of the pipe can be promoted, and the normal state can be quickly achieved.

[ Embodiment ] FIG. 4 shows a configuration diagram when the fan air volume in the fan coil 1 is variable. In this case, the controller 8'has a fan air volume of high ("H"), medium ("M"), and low ("L").
There are provided a fan air flow rate setting unit 8-7 for setting in multiple stages and a fan air flow rate increasing / decreasing unit 8-8 for sending a fan air flow rate increasing / decreasing command to the fan air flow rate setting unit 8-7.

The fan air flow rate increasing / decreasing step portion 8-8 and the set temperature difference ΔTs and the return water temperature difference ΔT from the temperature difference comparing portion 8-2.
Based on the comparison result with p, the fan air volume setting unit 8-7 controls the air volume setting operation. During “L” operation, ΔT ≦ ΔTs
When it becomes p, the operation is switched to ", M" operation to increase the fan air volume. If ΔT ≦ ΔTsp during “M” operation, “H”
Switch to operation to further increase the fan air volume. "H"
If ΔT ≧ ΔTsp + α during operation, the operation is switched to “M” operation to reduce the fan air flow. During "M" operation, ΔT ≧
When ΔTsp + α is reached, the operation is switched to “L” operation to further reduce the fan air volume.

The fan air volume increasing / decreasing step unit 8-8 compares the ΔT and ΔTsp from the temperature difference comparing unit 8-2 when the fan air volume is the maximum air volume "H", that is, during "H" operation. To the limit section 8-4. Further, the operation of the fan air flow rate increasing / decreasing step unit 8-8 is the same as the limit unit 8-4, and the post-start time measured by the post-start time measuring unit 8-3 is a predetermined time (1 hour in this example). It is prohibited until it exceeds.

FIG. 5 shows a processing flowchart in the control device 8 '. In the after-start-up time measuring unit 8-3, when the time after the fan coil 1 is started exceeds one hour (NO in step 501), the operation of the limit unit 8-4 and the fan air flow rate increasing / decreasing stage unit 8-8 Is allowed.

The fan air flow rate increasing / decreasing step portion 8-8 and the set temperature difference ΔTs and the return water temperature difference ΔT from the temperature difference comparison portion 8-2.
Based on the comparison result with p, the fan air volume setting unit 8-7 controls the air volume setting operation.

Now, ΔT> ΔTsp (step 50
2) and ΔT ≧ ΔTsp + α (YES in step 503), YES in step 504
Accordingly, the process proceeds to step 508, and the state of “L” operation is continued.

From such a state, when the return water temperature difference ΔT becomes small and ΔT ≦ ΔTsp is satisfied (step 502).
YES), and after confirming that the fan air volume increasing / decreasing step portion 8-8 is not in the “H” operation (NO in step 506),
The operation is switched to "M" operation to increase the fan air volume (step 507: point P1 shown in FIG. 6). As a result, the return water temperature difference ΔT returns to ΔT> ΔTsp.

During the "M" operation, if ΔT≤ΔTsp (YES in step 502), the fan air flow rate increasing / decreasing step portion 8-
8 is not in "H" operation (step 5
(NO in 06), the operation is switched to "H" operation to further increase the fan air volume (step 507: P2 point shown in FIG. 6).
As a result, the return water temperature difference ΔT returns to ΔT> ΔTsp. During this “H” operation, the fan air flow rate increasing / decreasing step portion 8-8 is
The comparison result of ΔT and ΔTsp from the temperature difference comparison unit 8-2 is sent to the limit unit 8-4. Thus, ΔT ≦ ΔTs
If it is p, by increasing the fan air volume,
Promotes heat exchange of the coil 1-2 and changes ΔT to ΔT> ΔTsp
It is possible to improve the efficiency of the heat source 2 by returning to the above and prevent the indoor draft.

When ΔT ≦ ΔTsp is satisfied during the “H” operation (YES in step 502), the limit unit 8-4 sends ΔT and Δ to the fan air flow rate increasing / decreasing stage unit 8-8.
Based on the comparison result with Tsp, the instruction opening degree θR to the automatic control valve 3 is read as the current opening degree, and the read current opening degree θR is output to the MIN section 8-6 as the upper limit opening degree θLIM (step 509).

As a result, the opening degree θR at that time is set as the upper limit opening degree θLIM, and the opening degree control (limit control) of the automatic control valve 3 is performed.
Is performed, that is, the flow rate at the time when the return water temperature difference ΔT becomes smaller than the set temperature difference ΔTsp at the maximum air volume “H” is set as the upper limit (P3 shown in FIG. 6).
Point), the flow rate is adjusted within a range that does not exceed this upper limit, and even if the return water temperature difference ΔT is insufficient, it does not become an overflow, and it is possible to prevent a low temperature difference of the return water and an overflow from occurring at the same time. To be done.

During the "H" operation, if ΔT ≧ ΔTsp + α (YES in step 503), the fan air volume increasing / decreasing step portion 8
After confirming that -8 is not in the "L" operation (NO in step 504), the operation is switched to the "M" operation to reduce the fan air volume (step 505). During "M" operation, ΔT ≧ Δ
If it becomes Tsp + α (YES in step 503), after confirming that the fan air volume increasing / decreasing step portion 8-8 is not in “L” operation (NO in step 504), switch to “L” operation to further reduce the fan air volume. (Step 505).
As described above, when ΔT ≧ ΔTsp + α, the power consumption of the fan can be reduced by reducing the fan air volume.

It should be noted that 1 has been set since the fan coil 1 was started.
Until the time elapses, even if the fan air volume is the maximum air volume “H” and the return water temperature difference ΔT is smaller than the set temperature difference ΔTsp, the current opening θR of the automatic control valve 3 is set to the upper opening θLI.
Since the limit control as M is not performed, the precooling / preheating of the pipe can be promoted at the time of starting the fan coil 1 in the morning, and the normal state can be quickly achieved.

[0031]

As is apparent from the above description, according to the present invention, in the first invention, the air volume of the fan is set to the maximum air volume.
Even if the return water temperature difference is smaller than the set temperature difference,
For example, the opening of the automatic control valve can be controlled with the opening at that time as the upper limit.
The maximum air volume of the fan is
When the flow rate becomes smaller than the set temperature difference, the upper limit
The flow rate is adjusted within the range not exceeding this upper limit.
Even if there is not enough temperature difference between the return water and
There is no flow rate, and there are
It is prevented from occurring at the same time. Further, in this first invention
If the fan airflow is not the maximum airflow, the return water temperature difference
Becomes smaller than the set temperature difference, the fan air volume increases
Therefore, the heat exchange of the coil is promoted and the efficiency of the heat source is improved.
It is possible to improve and prevent indoor draft
It In addition, the temperature difference between the return water and the set temperature is more than the specified value.
When the fan becomes larger, the air flow of the fan is reduced.
Power consumption can be reduced.

[0032]

In the second invention, the fan coil is activated.
Until the predetermined time has elapsed,
Even if the amount of water flowing back and forth is smaller than the set temperature difference,
Opening control is performed with the current opening of the automatic control valve as the upper limit.
Pre-cooling / pre-heating of the piping when starting the fan coil in the morning
It can be promoted, and can quickly shift to the normal state.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a main part of a fan coil air-conditioning control system, which is a reference example before starting description of the present invention.

FIG. 2 is a diagram showing a processing flow in a control device in this fan coil air conditioning control system.

FIG. 3 is a diagram illustrating a situation in which an upper limit value of a flow rate is regulated by this control device.

FIG. 4 is a fan coil air conditioning control system according to the present invention.
Is a block diagram showing an essential part of the implementation in the form of.

FIG. 5 is a diagram showing a processing flow in a control device in this fan coil air conditioning control system.

FIG. 6 is a diagram illustrating a situation in which an upper limit value of a flow rate is regulated by this control device.

[Explanation of symbols]

1 ... Fan coil, 1-1 ... Fan, 1-2 ... Coil,
2 ... Heat source, 3 ... Automatic control valve, 4R ... Return water passage, 4L ...
Outflow water passage, 5 ... Outflow water temperature sensor, 6 ... Return water temperature sensor, 7 ... Indoor temperature sensor, 8, 8 '... Control device, 8-1
... Temperature difference calculation section, 8-2 ... Temperature difference comparison section, 8-3 ... Post-start time measurement section, 8-4 ... Limit section, 8-5 ... Temperature PI
D section, 8-6 ... MIN section, 8-7 ... Fan air volume setting section,
8-8 ... Fan air flow increasing / decreasing step section.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F24F 11/02 102

Claims (2)

(57) [Claims] 1. An opening of an automatic control valve provided on a supply passage of water from a heat source to a fan coil, and
In a fan coil air-conditioning control system for controlling the air conditioning capacity of the fan coil by adjusting the air volume of the fan coil, the temperature difference between the incoming water and the returning water to the fan coil is measured. Based on the comparison result by the temperature difference comparing means for comparing the temperature difference of the return water measured by the temperature difference measuring means for the return water and the set temperature difference, When the difference between the return water temperature is smaller than the set temperature difference, the fan
If the air volume of the fan is not the maximum air volume, increase the air volume of the fan
Control so that the return water temperature difference is less than the set temperature difference.
Is greater than a specified value, the air volume of the fan is the minimum air volume
Otherwise, the wind that controls to reduce the air flow of the fan
Based on the comparison result of the amount control means and the temperature difference comparison means, the return water
The fan is operated when the temperature difference is smaller than the set temperature difference.
Fan coil air-conditioning control system, the valve opening control means for controlling the opening of the automatic control valve with the current opening of the automatic control valve as an upper limit when the air flow rate is the maximum. . 2. A fan coil air conditioner according to claim 1.
In the control system, a predetermined time has passed since the fan coil was activated.
Up to the present of the automatic control valve by the valve opening control means.
A fan coil air-conditioning control system comprising means for prohibiting opening control with an existing opening as an upper limit .