JPS59173646A - Controlling method of heat source device - Google Patents

Abstract

PURPOSE:To stably control the delivery water temperature in accordance with the limit value and the load of an air conditioner by a method wherein the control value of a circulating water temperature is determined to every rotational frequency of a pump for a heat source apparatus. CONSTITUTION:Signals Sr, which represent the rotational frequencies of pumps P1 and P2 and are obtained from tacho-generators TG1 and TG2, are given to a factor converter FCV and, upon being converted to percentage, given to one input terminal of a low value selector LSE. On the other hand, a signal Si, which represents the return water temperature thetai, is sent together with the set value SPi of the return water temperature thetai to an operator PID1 and, after being subjected to PID (proportion, integration, differentiation) operation in order to be turned to the instruction value of a circulating water temperature theta0, given to the other input terminal of the low value selector LSE. Accordingly, the circulating water temperature can be controlled continuously, resulting in enabling to stably control the rotational frequencies of the pumps without the generation of misjudgement of the quantity of air conditioning load with respect to controlling, even under the condition that the valve opening of air conditioning load does not conform to the circulating water temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in a method for controlling an air conditioning heat source device according to an air conditioning load amount.

[Prior art]

FIG. 1 is a configuration diagram of a refrigeration system shown as an example of a heat source device. In addition to being cooled by R1+R2, water is supplied to the air conditioning load AL such as a fan coil unit as water via the header H1, and then to the header H2 via the header.
The water is returned to the refrigerator R as return water, and the circulation is repeated.
1. The temperature of the water fed from R2 is detected by the temperature sensor T1, and the temperature of the return water is detected by the temperature sensor T2. Based on the detection power of the two, the controller CT determines the temperature of the return water and the temperature of the feed water. The air conditioning load is calculated by multiplying the temperature difference by the water supply amount, and the return water temperature is calculated according to the air conditioning load.
The cooling capacity of refrigerators R1 and R2 is simultaneously controlled so that y is constant, and the rotation speed of pumps Pi and P20 is set to 509 g.
Or it is controlled at the same time as 100%.

Therefore, the air conditioning load amount LA and the water supply temperature θ. As shown in FIG. 2, when the air-conditioning load LA is 0 to 50%, the rotational speed of the pumps P1 and P2 is set to 50%, and as the air-conditioning load LA increases, the water supply temperature θ increases. changes from 1θ℃ to 5℃, while the air conditioning load LA changes from 50 to 10℃.
At 0°, when the rotation speed of pumps Pi and P2 is 100%, the amount of water supplied is twice that when the pumps rotate at 50°, so the water supply temperature θO changes from 7.5°C as the air conditioning load LA increases. 5
It will change to ℃.

In addition, even if the water supply temperature θ0 is different between the water supply temperature of 5°C at 50 inch rotation and the water supply temperature of 7.5 °C at 100 inch rotation, the amount of water conveyed is doubled due to 100 inch rotation. The amount of heat does not change.

However, the valve opening degree of the air conditioning load AL is controlled according to the room temperature set value and the room temperature, and even if the water supply temperature θ0 suddenly changes, the valve opening degree does not respond immediately, and the previous opening degree is It is to be maintained.

Therefore, as the air conditioning load LA increases, the rotation speed increases to 100 times, and even if the water supply temperature θO changes from 5°C to 7.5°C, the valve opening will still be a small opening relative to 5°C. The actual flow rate flowing through the air conditioning load AL is small (7.5℃ water is returned to water with almost no temperature rise, so the air conditioning load LA has apparently decreased). The controller CT makes a judgment and returns to the state of 50 inch rotation even though the contracted load LA exceeds 50%.

In addition, as the air conditioning load amount LA decreases, the valve rotates by 50°, and even if the water supply temperature θO changes from 7.5°C to 5°C, the valve opening remains at a large opening relative to 7.5°C. The flow rate actually flowing through the air conditioning load AL is higher than necessary, and the water sent at 5°C causes an excessive temperature rise and becomes return water, causing the apparent increase in the air conditioning load LA. The CT determines that the air conditioning load amount LA is actually less than 50%, but it returns to the state of 100 rotations.

Therefore, in the past, the air conditioning load amount LA was 50%
If there is an increase or decrease in the vicinity, pumps P1 and P2 will be 509
The state of 6 rotations and 100% rotation was repeated reciprocally, resulting in an unstable control situation.

[Summary of the invention]

The present invention has the purpose of fundamentally solving the drawbacks of the conventional technology, and sets a limit value for the water supply temperature for each rotation speed of the pump for heat source equipment, and adjusts the water supply temperature according to this limit value and the air conditioning load. The present invention provides an extremely effective method for controlling a heat source device.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to FIG. 3 and subsequent figures showing embodiments.

Fig. 3 is a block diagram of a control circuit added to the controller CT, and Fig. 4 shows the air conditioning load amount LA, return water temperature θI, and water supply temperature θ0 obtained by control with the configuration shown in Fig. 3. In FIG. 3, the speed generator TG in FIG. 1, the pump Pi obtained from 'f'G2,
A signal Sr indicating the rotation speed of P2 is applied to a coefficient converter FCV, where it is converted into an O0 fraction and applied to one input of the low value selectors I and SE.

On the other hand, the signal St indicating the return water temperature θi is given to the calculator PID1 together with the set value SPi of the return water temperature θi.
Based on the power of both people (PID (proportional, integral, differential)
After no calculation is performed and the command value of n1 water supply temperature θ0 is obtained, it is applied to the other input of the low value selector LSE.

In this case, the command value for the water supply temperature θ0 is 0% when the water supply temperature θ0 is 10℃, and 100% when the water supply temperature θ0 is 5℃.
It is determined as a percentage of 0.00.

For this reason, pump PIIP! If both rotate at 50%, the output of the coefficient converter FCV will be 50%; similarly, if the rotation will occur at 100%, the output will be 100, and at 50% rotation, the command value from the calculator PID1 will be θ. When the command value is less than ~50q6, the low value selector LSE selects the command value and sends it to the arithmetic unit PID2 as a set value.
When the value exceeds 0%, the low value selector LSE selects the coefficient converter F.
A signal S selects the output of CV and sends this value to the calculator PID2 as a set value, and indicates this set value and the water supply temperature θ0 from the temperature sensor Tl.

Based on this, the computing unit PID2 performs PID calculation and sends a signal Sc for controlling the water supply temperature θ0 to the refrigerator R1+R2, so that the water supply temperature θ0 is controlled as shown in Fig. 4, and the air conditioning load amount LA becomes θ~ When the air conditioning load LA is 25%, the water supply temperature θ0 decreases according to the air conditioning load LA, whereas when the air conditioning load LA is 25% to 50%, the water supply temperature θ0 remains at a constant value of 7.5℃. This determines the limit value LV+ at the time of 50-inch rotation. Also, at 100% rotation, the output of the coefficient converter FCV becomes 100 inches, and the command value from the calculator PII) becomes 1.
While it is less than 00%, the low value selector LSg always selects the command value and gives this 2t as a set value to the calculator PID2.
When the temperature is less than H, the water supply temperature θ0 decreases according to the air conditioning load amounts T and A, and reaches the limit value LV2 at 100% rotation at 100% of the air conditioning load amount Lh.

In addition, in Fig. 4, the air conditioning load amount LA is 'N25.
~50 degrees, the return water temperature θi fC changes, but
Since the temperature difference between the return water temperature θi and the water supply temperature θ0 increases according to the air conditioning load iLA, cooling is performed in accordance with the air conditioning load amount TJA.

Therefore, even if the air conditioning load LA increases or decreases in the vicinity of 50 inches, the water supply temperature θ0 will be continuously controlled, and even if the air conditioning load AL valve μm 1 degree does not immediately respond to changes in the water supply temperature θ0, the water supply temperature θ0 will be continuously controlled. The device CT no longer misjudges the air conditioning load amount LA, and the rotation speeds of the pumps PI and P2 can be controlled stably.

Also, when the load decreases and a decision is made to control the number of units and one unit is operated, the rated capacity of one unit is set to 100%, and when the load changes to half of that, 50%, limit control is performed in the same way. .

In FIG. 4, it is recognized that the limit value LV2 is not very effective, but when the rotational speed is set in three or more stages, it acts in the same way as the limit value LV+ and becomes effective.

However, the structure shown in FIG. 3 may be realized by the arithmetic function of a microprocessor, etc., and the selection of the specific structure is arbitrary as long as the control state shown in FIG. 4 is realized. 1 Number of refrigerators R1 and Rz, water supply temperature θo1, return water temperature θi, and limit value LV.

, LV2, etc. may be determined depending on the conditions, and can be applied not only to refrigeration equipment but also to hot water supply equipment including boilers and the like, and various modifications are possible.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, since the water supply temperature is continuously controlled, even if the valve opening degree of the air conditioning load does not immediately respond to the water supply temperature, misjudgment of the air conditioning load amount can be avoided. This does not occur, and the rotational speed of the pump can be controlled stably, resulting in a remarkable effect in controlling the air conditioning heat source device.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of a refrigeration system showing an example of a heat source device;
The figure shows the relationship between the air conditioning load and the water supply temperature in the past. Figure 3 and subsequent figures show the embodiments of the present invention. Figure 3 is a block diagram of the control circuit, and Figure 4 shows the relationship between the air conditioning load and the water return temperature. It is a diagram showing the relationship between temperature and water supply temperature.
・Pump, CT..., controller, F...flow meter,
T1~T2...Temperature sensor, TG...Speed generator, FC...Coefficient converter, PIDl, PID2
...φ・Arithmetic unit, LSE ...Low value selector, θ0
... Water supply temperature, θi ... Return water temperature, LA.
...Air conditioning load amount, LVt, LV2...Limit value. Patent Applicant Yamatake No. 1 Newel Co., Ltd. Agent Masaki Yamakawa (and 1 other person) Figure 3 Figure 4 + “Cl

Claims (1)

[Claims] In a method of controlling the rotation speed of a heat source equipment pump in stages so as to keep the return water temperature constant according to the air conditioning load, a limit value of the water supply temperature is determined for each rotation speed of the pump, and the limit value is set for each rotation speed of the pump. A method for controlling a heat source device, characterized in that the water supply temperature is controlled according to a value and the air conditioning load amount.