JP3112596B2 - Absorption refrigerator and control method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an absorption refrigerator including a hot water system communicating with a heat source, a cooling water system communicating with a cooling load, and a cooling water system communicating with a cooling tower, and a control method therefor.

[0002]

2. Description of the Related Art It has been conventionally proposed to use waste heat in a cogeneration system or the like using a gas engine for a hot water-fired absorption refrigerator to thereby make effective use of energy. And in such a hot water absorption absorption refrigerator,
The hot water system communicates with a cogeneration system, which is a heat source, and supplies the waste heat to a hot water-fired absorption refrigerator.

Here, as a method of controlling a hot water-fired absorption refrigerator, a technique for controlling a flow rate of a hot water system has been conventionally known. FIG. 5-7 shows such a prior art. FIG.
At -7, a hot water system is indicated by reference numeral 2, a cold water system is indicated by reference numeral 3, and a cooling water system is indicated by reference numeral 4. In each piping system, reference symbol I is attached to the inlet side (the side that flows into the hot water-fired absorption refrigerator), and reference symbol O is attached to the outlet side (the side that flows out of the hot water-fired absorption refrigerator). .

[0005] In the hot water-fired absorption refrigerator 1 shown in FIG. It is sent to the opening adjusting means 7. Then, by adjusting the opening degree of the three-way valve 6, the flow rate of the hot water flowing through the branch pipe 2B bypassing the absorption refrigerator 1 is controlled.

In the hot water-fired absorption refrigerator 8 shown in FIG. 6, the temperature of the hot water flowing through the inlet pipe 2I of the hot water system 2 is measured by the temperature detecting means 9 and the result is measured by the opening adjusting means of the three-way valve 6. 7 On the other hand, in the hot water-fired absorption refrigerator 10 shown in FIG. 7, the liquid temperature detecting means 11 is provided in the outlet pipe 20 of the hot water system 2, and the output is sent to the opening degree adjusting means 7 of the three-way valve 6. ing.

In the conventional hot water-fired absorption chillers 1, 8 and 10 shown in FIGS.
The liquid temperature of I is set to be, for example, 31 ° C.

[0007]

The effect of the hot water flow rate control in FIGS. 5 to 7 is obtained when the flow rate is reduced to 20% or less of the rated flow rate. In this case, the heat transfer coefficient of the heat transfer tube of the regenerator is reduced because the heat transfer coefficient inside the heat transfer tube is deteriorated. Along with this, the solution regeneration temperature in the regenerator decreases, and the performance of the hot water-fired absorption refrigerator decreases.

In the hot water-fired absorption chillers 1, 8, and 10 shown in FIGS.
Hot water bypasses the refrigerator even if the temperature of the hot water system inlet 2I (see FIG. 6) or the temperature of the hot water system outlet temperature 20 (see FIG. 7) is too low to supply hot water to the refrigerator. It is configured to circulate in hot water system 2
Must continue to drive the pump 12 located at That is, in the related art as shown in FIGS. 5 to 7, it is wasteful to continue to drive the hot water pump 12 even when it is not necessary to supply hot water to the hot water absorption chiller, which is called an effective use of energy. The problem arises that goes against the gist.

Further, in the hot water-fired absorption refrigerator 1 shown in FIG. 5, the opening adjusting means 7 sends the cooling water to the refrigerator 1 when the temperature of the outlet side 30 of the cold water system 3 is lower than a predetermined temperature (for example, 7 ° C.). The flow rate of hot water is reduced. Therefore, even when the exhaust heat can be used from the heat source (exhaust heat source) communicating with the hot water system 2, the amount of hot water sent to the refrigerator 1 decreases if the liquid temperature of the cold water system outlet side 30 is equal to or lower than the predetermined temperature. Therefore, there is a problem that exhaust heat is not sufficiently utilized. Such a situation is contrary to the purpose of effective use of energy.

The present invention has been proposed in view of the problems of the prior art as described above, and has a load, a mechanism,
It is an object of the present invention to provide a hot water-fired absorption refrigerator capable of maximizing refrigeration capacity and efficiency in response to other various conditions, and a control method thereof.

[0011]

The absorption refrigerator according to the present invention comprises:
In an absorption refrigerator including a hot water system that communicates with a heat source, a cold water system that communicates with a cooling load, and a cooling water system that communicates with a cooling tower, the water passes through the discharge side line of the hot water system and travels from the absorption refrigerator to the heat source. The system includes a hot water outlet temperature measuring means for measuring the temperature of the hot water, and a cooling water inlet temperature control means for adjusting the temperature of the cooling water flowing into the absorption refrigerator in response to the output of the measuring means.

Further, the control method of the absorption refrigerator according to the present invention is as follows.
In a control method of an absorption refrigerator including a hot water system communicating with a heat source, a cooling water system communicating with a cooling load, and a cooling water system communicating with a cooling tower, the absorption refrigerator flows through a discharge side line of the hot water system. A hot water outlet temperature measuring step of measuring the temperature of the hot water heading toward the heat source; and a cooling water inlet temperature controlling step of adjusting the temperature of the cooling water flowing into the absorption refrigerator in response to the measured hot water outlet temperature. .

In practicing the present invention, the above-described cooling water inlet temperature control means or cooling water inlet temperature control step is preferably performed by adjusting the flow rate of cooling water passing through the cooling tower. It is also preferable that the cooling be performed by adjusting the cooling capacity of the cooling tower.

[0014]

According to the absorption refrigerator of the present invention having the above-described configuration and the control method thereof, the temperature of the hot water flowing from the absorption refrigerator to the heat source flowing through the discharge line of the hot water system is measured, The temperature of the cooling water flowing into the absorption refrigerator is adjusted in response to the measured hot water outlet temperature. In other words, the lower the cooling water temperature on the inlet side, the better the capacity of the absorption refrigerator becomes.However, if the cooling water temperature on the inlet side is too low, the heat supplied from the hot water system is consumed more. become. Therefore, the liquid temperature of the hot water flowing from the absorption refrigerator to the heat source, the hot water flowing through the outlet side of the hot water system, is detected, and when the hot water system outlet side temperature falls below a predetermined value, the cooling water inlet temperature is raised. I have. As a result, the cooling water inlet temperature is set as low as possible without excessively consuming the heat supplied from the hot water system.

Here, in the present invention, the cooling water inlet temperature is controlled, and the flow rate of the cooling water supplied to the hot water-fired absorption refrigerator is constant. In other words, according to the present invention, the absorption chiller is always supplied with a fixed amount of cooling water, and even when hot water is not supplied to the absorption chiller as in the pump in the conventional hot water system shown in FIGS. Since there is no situation of being driven, there is no waste in driving the pump (for hot water) disposed in the hot water system and the pump (for cooling water) disposed in the cooling water system. Therefore, electric power consumed by auxiliary equipment such as a pump (auxiliary equipment electric power) is saved, which meets the demand for energy saving.

Further, the heat transfer performance of the heat transfer tube of the regenerator, which is caused by the hot water flow rate control, does not decrease. Therefore, it is possible to prevent a decrease in the performance of the hot-water-fired absorption refrigerator due to this, and in this respect, it further meets the demand for energy saving.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the drawings, common members are represented by using common reference numerals.

In FIG. 1, a hot-water-absorption absorption refrigerator generally designated by reference numeral 20 has a hot-water system 2, a cold-water system 3, and a cooling-water system 4. The symbol I is attached to the outlet (the side flowing out of the hot water absorption absorption chiller). In each piping system, pumps provided for supplying and discharging water are each denoted by a letter P as a subscript.

The cooling water system 4 is provided with a cooling tower 32 for lowering the temperature of the cooling water heated by returning from the absorption refrigerator 20. The outlet pipe 40 of the cooling water system is branched into a pipe L1 toward the cooling tower 32 and a bypass pipe L2 that bypasses the cooling tower 32 and joins the inlet pipe 4I. A three-way valve V1 is provided at the junction of the bypass pipe L2 and the inlet pipe 4I of the cooling water system.

The three-way valve V1 is configured so that the flow rate of the cooling water flowing from the bypass pipe L2 side, that is, the flow rate of the bypass pipe L2 can be controlled. here,
If the flow rate of the bypass pipe L2 is increased, the flow rate of water that is not cooled by the cooling tower 32 (the flow rate of water that bypasses the cooling tower 32) is increased. The temperature (the temperature of the cooling water flowing through the cooling water system inlet pipe) increases. On the other hand, if the flow rate of the bypass pipe L2 is reduced, the flow rate of the water sent to the cooling tower 32 via the pipe system L1 and cooled is increased. The temperature drops.

The hot water-fired absorption refrigerator 20 shown in FIG.
Is provided with a temperature detecting means 34 in the outlet side pipe 2O. The output of the temperature detecting means 34 is supplied to the signal transmission line SL
1 through an opening control means 36 for controlling the opening of the three-way valve V1 (corresponding to the flow rate of the bypass pipe L2), the flow rate of the bypass pipe L2 or the cooling water inlet side pipe 4
The temperature of the cooling water flowing through I is controlled by the temperature of the hot water at the outlet side 20 of the hot water system 2.

The control of the cooling water liquid temperature of the cooling water inlet pipe 4I by the hot water liquid temperature of the hot water system outlet pipe 20 will be described below with reference to FIG.

During the operation of the hot water-fired absorption refrigeration system 20, the temperature of the hot water flowing through the hot water system outlet pipe 2O (indicated by the symbol T in FIG. 2) is measured by the temperature detecting means 34 (step S1). The measured hot water temperature T is used as the signal transmission line SL
1 and is sent to the opening degree adjusting means 36, and it is determined whether or not the value is equal to or less than a predetermined value (step S2). The predetermined value may be a function of the cooling water inlet temperature or the cooling water inlet temperature. If the measured hot water temperature T is lower than the predetermined value (YES in step S2), the temperature of the cooling water flowing through the cooling water system inlet side pipe 4I and supplied to the refrigerator 20 becomes too low. Therefore, it is determined that the heat supplied from the hot water system is consumed extra. Therefore, the opening of the three-way valve V1 is adjusted to increase the flow rate of the cooling water flowing through the bypass pipe L2 (Step S).
3).

On the other hand, if the measured hot water liquid temperature T is higher than the predetermined value (NO in step S2), there is no problem even if the temperature of the cooling water supplied to the refrigerator 20 is lowered. It is determined that there is. As described above, the lower the temperature of the cooling water supplied to the refrigerator, the higher the performance of the refrigerator. Therefore, in such a case, the temperature of the cooling water flowing through the cooling water system inlet 4I and supplied to the refrigerator is lowered. Control is performed in order to do so. In the case of the embodiment of FIG. 1, the opening degree of the three-way valve V1 is adjusted to reduce the flow rate flowing through the bypass pipe L2 (step S4). In some cases, the flow rate of either of the tubes L1, L2 will be zero.

Thereafter, after performing the control process of step S3 or S4, the process returns to step S1 again.

FIG. 3 shows another embodiment of the present invention. In this embodiment, the number of rotations of the cooling fan 40 of the cooling tower 38 provided in the cooling water system 4 depends on the temperature of the hot water flowing through the hot water system outlet side piping system 2O transmitted via the signal transmission line SL2 (detection (Measured by the means 34). More specifically, if the temperature of the hot water is high, the rotation speed of the cooling fan increases, and if the temperature of the hot water is low, the rotation speed of the cooling fan decreases.

The manner of controlling the coolant temperature in the embodiment of FIG. 3 will be described with reference to FIG. 4. First, the temperature of the warm water flowing through the hot water system 2O by the temperature detecting means 34 (in FIG. Is measured (step S11). And
It is determined whether the value is equal to or less than a predetermined value (step S12).

If the measured hot water temperature T is lower than the predetermined value (YES in step S12), the temperature of the cooling water flowing through the cooling water system inlet side pipe 4I and supplied to the refrigerator 20 becomes too low. Therefore, it is determined that the heat supplied from the hot water system is consumed extra. Therefore, in order to raise the temperature of the cooling water flowing through the inlet pipe 4I of the cooling water system 4,
That is, the rotation speed of the cooling fan 40 is reduced. (Step S13).

On the other hand, if the measured hot water liquid temperature T is higher than the predetermined value (NO in step S12), it flows through the cooling water system inlet 4I and is supplied to the refrigerator as in the case of FIGS. Control is performed to lower the cooling water temperature. That is, the rotation speed of the cooling fan 40 is increased (step S
14) In the cooling tower 38, the cooling water temperature is further reduced.

Hereinafter, step S13 or step S1
After performing the control process of No. 4, the process returns to step S11 again.

The illustrated embodiment is merely an example, and is not intended to limit the technical scope of the present invention. For example, a wide variety of changes and modifications can be made to the manner of controlling the temperature of the cooling water supplied to the hot water-fired absorption refrigerator, the arrangement of the temperature detecting means, and the like.

[0032]

The effects of the present invention are listed below.

(1) Since the cooling water inlet temperature is set as low as possible without excessively consuming the heat supplied from the hot water system, the refrigeration capacity and cooling efficiency of the hot water absorption absorption chiller can be reduced. It is possible to improve as much as possible.

(2) Energy saving is achieved by effective use of low-temperature exhaust heat.

(3) The power consumed by auxiliary equipment such as a pump (auxiliary equipment power) is saved, which further meets the demand for energy saving.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a view showing a control flowchart of the embodiment of FIG. 1;

FIG. 3 is a block diagram showing one embodiment of the present invention.

FIG. 4 is a view showing a control flowchart of the embodiment of FIG. 3;

FIG. 5 is a block diagram showing an example of a conventional hot-water-fired absorption refrigerator.

FIG. 6 is a block diagram showing another example of the conventional hot-water-fired absorption refrigerator.

FIG. 7 is a block diagram showing still another example of the conventional hot water-fired absorption refrigerator.

[Explanation of symbols]

 1, 8, 10, 20, 30 ... hot water-fired absorption refrigerator 2 ... hot water system 3 ... cold water system 4 ... cooling water system 2I, 3I, 4I ... inlet side piping 2O, 3O, 4O: Outlet piping 5, 9, 11, 34 ... Temperature detecting means 6, V1 ... Three-way valve 7, 36 ... Opening degree adjusting means 2B ... Branch pipe 32, 38 ... Cooling tower 40: cooling fan L1: pipe L2: bypass pipe SL1, SL2: signal transmission line

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-161767 (JP, A) JP-A-47-5436 (JP, A) JP-A-64-13466 (JP, U) (58) Investigation Field (Int.Cl. ⁷ , DB name) F25B 15/00 306

Claims (2)

(57) [Claims] 1. An absorption refrigerator comprising a hot water system communicating with a heat source, a cooling water system communicating with a cooling load, and a cooling water system communicating with a cooling tower. Hot water outlet temperature measuring means for measuring the temperature of hot water flowing from the refrigerator to the heat source, and cooling water inlet temperature control means for adjusting the temperature of cooling water flowing into the absorption refrigerator in response to the output of the measuring means. An absorption refrigerator. 2. A method for controlling an absorption refrigerator including a hot water system communicating with a heat source, a cooling water system communicating with a cooling load, and a cooling water system communicating with a cooling tower. A hot water outlet temperature measuring step of measuring the temperature of hot water flowing from the absorption refrigerator to the heat source; anda cooling water inlet temperature control step of adjusting the temperature of cooling water flowing into the absorption refrigerator in response to the measured hot water outlet temperature. And a method for controlling an absorption refrigerator.