JPS5845438A - Control system for solar heat utilizing absorption type refrigerating machine - Google Patents

Abstract

PURPOSE:To utilize the solar heat properly by judging the advantage of utilizing the solar heat, based on weather conditions and the temperature of cool water from the absorption type efrigerating machine, and thereby controlling a heat collecting pump. CONSTITUTION:The solar heat utilizing absorption type refrigerating machine is consisting of a heat collector 1, a heat accumulating tank 2, the heat collecting pump 7, the absorption type refrigerating machine 3, an air conditioner 4, a cooling tower 5 and an auxiliary heat source 6. The temperature of the cool water from the refrigerating machine 3 to the air conditioner 4 is measured by a meter 11 and a cool water temperature signal is inputted into a control means 12 together with the signals of a sunshine amount meter 8, an atmospheric temperature meter 9 and an atmospheric humidity meter 10, in order to estimate a heat collecting amount and decide whether the solar heat is to be utilized or not, thereby controlling the heat collecting pump 7. The measurements of the cool water temperature and the atmospheric humidity may be omitted and assumed values therefor may be employed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a solar absorption type absorption refrigerator.

Conventional solar absorption refrigerators are operated based on the temperature difference between the entrance and exit of the collector. That is, when the temperature difference is large enough, the operation of the heat collection pump that supplies the heat collection medium to the heat collector is continued, inputting solar heat to the refrigerator, and mIf
When the difference became small, the heat collection pump was stopped and heat input to the refrigerator was cut off. However, when the heat collector pump is stopped, the temperature difference between the inlet and outlet of the heat collector has no meaning, so the above-mentioned method often has the disadvantage that it is not possible to appropriately determine whether to start operation of the heat collector pump.

The present invention has been made based on the above-mentioned matters, and an object of the present invention is to provide a control device for a solar heat absorption chiller that appropriately determines and controls whether or not the collector can operate, regardless of whether the collector pump is in operation or stopped. With the goal.

The present invention is characterized by a predicted value of the amount of heat collected when a heat collection pump is operated based on the weather condition values of outside air temperature, outside air humidity, and the amount of solar radiation per day, and the value of the chilled water temperature of the absorption chiller. is calculated, and the entire operation of the heat collection pump is controlled based on this calculated value.

Embodiments of the present invention will be described below with reference to all the drawings.

Figure 1 shows the configuration of a field heat absorption type absorption chiller equipped with an example of the device of the present invention. In the figure, 1 is a heat collector;
2 is a heat storage tank, 3 is an absorption refrigerator, 4 is an air conditioner, 5 is a cooling tower, 6 is an auxiliary heat source, and 7 is a heat collection pump. The absorption refrigerator 3 includes, for example, a high temperature generator 3a, a low temperature generator 3b, and a condenser 6.
It consists of a 3C% evaporator 3d and an absorber 3e. 8 is a solar radiation measuring device for measuring the amount of solar radiation, 9 is an outside temperature measuring device for measuring outside air temperature, 10 is an outside air humidity measuring device for measuring outside air humidity, 11 is a cold water temperature measuring device for measuring cold water temperature, 12 is a control means that determines whether or not solar heat can be utilized based on the above-mentioned measured values, and controls the heat collecting pump 7 based on the result.

The entire determination processing operation of the control means 12 will be described below.

The amount of heat collected by the heat collector 1 Qc is given by the following equation.

Qc=A"S"Jc+B@S"(Tw-T,)...
・・・・・・・・・・・・・・・ (1) However, S is the heat collection area, A is the coefficient representing solar radiation absorption t-, B is the function representing heat radiation loss, and Tw is the heat collection temperature.

T is the outside temperature.

On the other hand, the generator 3b is connected to the hot water heat exchanger from the heat collector 1.
The amount of heat Qo given to the solution inside matches the amount of heat collected. In other words, the following equation holds.

However, RG is the heat exchanger thermal resistance, and TL is the generator solution temperature. ,,,Furthermore, this solution temperature Tt is the cold water temperature T
0, determined by the cooling water temperature and the amount of heat generated by the speaker. Here, the cooling water temperature is the outside air humidity T,,H.

and the amount of heat generated by the speaker Qo, that is, the amount of heat collected Qc. Therefore, the solution temperature Tx is the outside air temperature and humidity T i I
H! , , S is determined as a function of the cold water temperature T and the amount of heat input. That is, TL = f (T, , H-, T-, Q, c)-
--(3) However, ) Ia is outside air humidity %) (e is cold water temperature. Based on equations (1) to (3) above, prediction of heat collection tQc @Qc'? can be calculated. , This makes it possible to determine whether or not heat collection is possible.Therefore, the control means of the present invention uses the control signal St ratio output according to the magnitude of the predicted value odor c based on equations (1) to (3). For example, when the predicted value Qa exceeds the predetermined value n,
In all cases, 0 is output. In addition, as shown in FIG. 2, a value that increases with the increase of the predicted value may be output as the control signal S.

The control means of the present invention controls the heat collecting pump 7 using the control signal S. That is, in the case where the control signal S is given in the former manner, the heat collecting pump 7 is stopped when S=0, and is operated when S=1. control signal S
When S is given as in the latter case, the capacity of the heat collection pump 7, for example, the number of pumps or the number of revolutions, is completely adjusted depending on the magnitude of S.

This allows appropriate input control of solar heat.

In addition, in the present invention, the outside air humidity H1 and the cold water temperature T,
A similar effect can be obtained by omitting the measurement of , and using its assumed value. In this case, the amount of solar radiation Jc and the outside air temperature T are measured with a measuring instrument, and the outside air humidity H and the cold water temperature T are assumed to be f[H, and T, and sound. In this case, the calculation within the control means 12 uses the above-mentioned equation (3) modified as follows.

TL=f(T・,H・,T,,Qc)・・・・・・・・・
- (4) And in the control means 12 of the present invention, the above-mentioned (υ).

Calculate the predicted value 6ck based on formulas (2) and (4),
Control signal 5tl-output. The method of determining the control signal S and the method of adjusting the capacity of the heat collection pump 7 based on the signal S are the same as in the embodiment of the present invention described above.

As described in detail above, the present invention enables the heat collecting pump to be operated appropriately, and solar heat can be used more effectively.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the 111 construction of an embodiment of the control device according to the present invention, and Fig. 2 is a diagram showing the amount of heat collected to explain the control system #a in the control device according to the present invention. 3 is a diagram showing the relationship between a predicted value Qc and a control signal S. FIG. DESCRIPTION OF SYMBOLS 1... Heat collector, 2... Heat storage tank, 3... Absorption refrigerator, 4... Air conditioner, 7... Heat collection pump, 8... Solar radiation meter, 9... ...Outside air temperature measuring device, 10...Outside air humidity measuring device, 11...Cold water temperature measuring device, 12...Control means. Agent Patent Attorney Toshiyuki Usuda

Claims (1)

[Claims] 1. In a solar absorption type absorption refrigerator equipped with a heat collector,
A solar heat utilization absorption type characterized by comprising a control means 7 for determining whether or not solar heat utilization is possible using weather condition values and chilled water temperature values and sounds from an absorption chiller, and controlling a heat collection pump based on the determination result. Refrigerator control device. 2. The control device for a solar heat absorption type refrigerator according to claim 1, characterized in that solar radiation, outside air @ degree, and outside air humidity are used as weather condition values. 3. The control device for a solar absorption type absorption refrigerator according to claim 2, characterized in that the amount of solar radiation, outside air temperature, outside air humidity, and chilled water temperature are each measured by one controller. 4. Measure the amount of solar radiation and the outside temperature with measuring instruments, and use the outside air humidity and cold water temperature as assumed values.1
A control device for a solar absorption type absorption refrigerator according to claim 2, wherein r: %.