JPH0621737B2 - Absorption refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an improvement of an absorption refrigerator (hereinafter referred to as an absorption refrigerator of this type) that operates by utilizing heat of hot water of an engine jacket.

(B) Conventional technology As a conventional technology of this type of absorption refrigerator, for example, as disclosed in Japanese Patent Laid-Open No. 52-133631, Japanese Utility Model Laid-Open No. 57-5677, etc., an engine jacket and this type of There is a hot water circuit that connects a generator of an absorption refrigerator with a hot water passage having a flow control valve that bypasses the generator.

(C) Problems to be Solved by the Invention In the above-mentioned conventional one, when the absorption refrigerating machine of this type is started, the flow rate of the hot water flowing to the generator is decreased while the hot water bypassing the generator is reduced. Although there is an advantage that it is possible to easily prevent excessive temperature drop of hot water returning to the engine jacket by increasing the flow rate, that is, excessive cooling of the engine, it takes a long time from the start of this type of absorption refrigerator to the normal operation. There is a problem that requires (for example, about 3 hours).

In view of this problem, the present invention can shorten the time from the start to the transition to steady operation (hereinafter referred to as the rise time), and the engine will be too cold during that period (excessive return temperature of the heat source fluid to the equipment side). It is an object of the present invention to provide an absorption refrigerating machine of this type capable of reducing the above.

(D) Means for Solving Problems As a means for solving the problems, the present invention stores a detection mechanism for detecting a physical quantity associated with a change in the absorption refrigeration cycle or a program for controlling the flow rate of the cooling fluid at startup. This type of absorption refrigerator has a timer and a control mechanism that gradually increases the cooling fluid supplied to the machine from a small amount during the period from startup to transition to steady operation by a detection mechanism or a signal from the timer. is there.

(E) Operation In the present invention, the flow rate of the cooling fluid supplied to this type of absorption refrigerator is adjusted at the time of start-up to gradually increase from a small amount to reduce heat radiation to the outside of the machine at the initial stage of start-up. Action (function) that accelerates the temperature rise and concentration of the absorption liquid circulating inside
Can be placed in this type of absorption refrigerator.

Therefore, according to the present invention, the rise time of this type of absorption refrigerator can be shortened as compared with the conventional one, and an excessive temperature drop of the heat source fluid flowing out from the generator is eliminated in a short time,
It can also reduce the engine and other equipment from overcooling.

(F) Embodiment FIG. 1 is a schematic structural explanatory view showing an embodiment of an absorption refrigerator of this kind according to the present invention, wherein (1) is a generator (G) and a condenser (C). A condenser, (2) an evaporative absorber comprising an evaporator (E) and an absorber (A), (H _ex ) a solution heat exchanger,
(P _R ) is a pump for the refrigerant liquid, (P _A ) is a pump for the absorbing liquid, and these are the pipe (3) through which the refrigerant liquid flows down, the pipes (4), (5) through which the refrigerant liquid flows back, The pipes (6), (7), (8) through which the liquid is sent and the pipes (9), (10) through which the absorbing liquid flows are connected to form a circulation path for the refrigerant (water) and the absorbing liquid (lithium bromide aqueous solution). I am configuring.

(11), (12), (13) and (14) are heat exchangers incorporated in the generator (G), the condenser (C), the evaporator (E) and the absorber (A), respectively. (15) and (16) are tubes for flowing cold water connected to the heat exchanger (13), and (17), (18) and (19) are cooling water connected to the heat exchangers (14) and (12). It is a flowing pipe, and the pipe (17) is provided with a pump (P _C ) for cooling water.

(J) is equipment such as engine and power plant (not shown)
This jacket is used to cool the heat exchanger.The jacket and the heat exchanger (11) are connected by pipes (20) and (21) to form a circulation path for hot water for the heat source of the generator (G). ing. (twenty two)
Is a pipe for bypassing the hot water generator (G), and this pipe is connected to the pipe (20) and the pipe (21) via a three-way valve (V ₁ ).
Further, a pump for hot water circulation having the (P _H) is a tube (20).

(P ₁ ) is a detector for detecting the hot water temperature at the outlet of the heat exchanger (11), (S ₂ ) is a detector for detecting the cooling water temperature at the outlet of the heat exchanger (12), and (S ₃ ) is a generator. A detector for detecting the temperature of the absorbing liquid in (G), (S ₄ ) is a refrigerant liquid reservoir (23) provided in the evaporator (E)
(T) is a timer. Then, the discharge amount of the cooling water pump (P _C ) is adjusted via the controller ( _CR ) by the signal of any of these detectors or the signal of the timer. Incidentally, so as to adjust the degree of opening of the cooling water pump (P _C) a flow control valve provided in the tube (17) instead of controlling the discharge amount of (V ₂₎ [a valve indicated by broken lines in FIG] Is also good.

In addition, (S) is a detector that senses the cold water temperature at the outlet of the heat exchanger (13), and the signal of this detector controls the opening of the three-way valve (V ₁ ) via the temperature controller (C _T ). You can do it.

Next, an example of the operation of the absorption refrigerating machine (hereinafter referred to as this machine) configured as described above will be described. Note that here,
The case where the control of the cooling water flow rate is performed by adjusting the opening degree of the flow rate control valve (V ₂ ) by the signal of the detector (S ₁ ) will be described.

Immediately after the start of the operation of this machine, the temperature of the absorbing liquid circulating in the generator (G) is close to the outside air temperature, so the hot water that has flowed into the heat exchanger (11) at about 85 ° C cools down, and this heat It flows out from the exchanger at about 60 ° C. And immediately after the start of operation,
If the flow control valve (V ₂ ) is left unthrottled, the cooling water causes a large amount of heat dissipation to the outside of the machine, so that the saturated vapor pressure and temperature in the generated condenser (1) rise slowly and the heat exchanger (11 ) The rise of the hot water temperature at the outlet will also be slow, and the jacket (J) on the equipment side will be too cold.

In this case, when the temperature sensed by the detector (S ₁ ) reaches 60 ° C., the signal from this detector reduces the opening of the flow control valve (V ₂ ) to 20%, and the signal is supplied to the unit. The cooling water flow rate is reduced to about one-fifth that of steady-state operation. As a result, the amount of heat radiated by this machine is reduced to about 1/5, and the temperature of the absorbing liquid in the generator (G) and the saturated vapor pressure rise rapidly. Then, the detected temperature of the detector (S ₁ ) is 5
Every time the temperature rises, the flow control valve (V ₂ ) is opened by 40%, 6
The temperature is increased by 20% from 0%, and when the temperature sensed by the detector (S ₁ ) reaches 80 ° C., the opening is set to 100%, and the operation is shifted to steady operation.

In this way, in this machine, the cooling water flow rate is adjusted at the time of startup to reduce the heat radiation to the outside of the machine, so that the temperature of the absorbing liquid circulating in the generator (G) is rapidly raised and the generated condensation occurs. The pressure inside the vessel (1) is quickly increased to prevent the jacket (J) of the engine or the like from being overcooled for a long time, and the rise time is shortened.

It should be noted that in connection with changes in the temperature, vapor pressure and concentration of the circulating absorption liquid, that is, changes in the absorption refrigeration cycle, the detector (S
₂ ), (S ₃ ), and (S ₄ ) sensed values also change,
The opening of the flow rate control valve (V ₂ ) or the discharge amount of the cooling water pump (P _C ) may be controlled by the signal of any of these detectors, and the operation at the time of start-up may be confirmed in advance by experiments. Alternatively, the control may be performed by a signal of a timer (T) in which a program for controlling the flow rate of the cooling fluid at startup is incorporated based on the result of this experiment.

FIG. 2 is a schematic structural explanatory view showing another embodiment of this type of absorption refrigerator according to the present invention, and the same components as those in the embodiment shown in FIG. is doing. In this embodiment, the flow rate of the cooling water that bypasses the heat exchanger (14) of the absorber (A) is controlled, so that heat radiation to the outside of the machine at the time of startup is reduced. In FIG. 2, (V ₃ ) is a three-way valve provided in the pipe (18), and (24) is a pipe for cooling water bypass.

(G) Effect of the Invention As described above, the present invention incorporates a detection mechanism for detecting a physical quantity associated with a change in the absorption refrigeration cycle of this type of absorption refrigerator or a program for controlling the flow rate of the cooling fluid at the time of startup. Equipped with a timer that gradually increases the cooling fluid supplied to the inside of the machine from a small amount until the control mechanism operates by the signal of the detection mechanism or the timer to shift from the start to the steady operation, and the heat dissipation to the outside at the start By reducing the temperature and vapor pressure of the absorption liquid in the generator quickly, it has the effect of shortening the start-up time of this type of absorption refrigerator, and also the equipment such as the engine. It is possible to prevent an excessive temperature drop of the fluid returned to the side (for example, jacket hot water) from continuing for a long time, and to have an effect that the adverse effect on the operation of the equipment side can be minimized.

[Brief description of drawings]

FIG. 1 is a schematic configuration explanatory view showing an embodiment of an absorption refrigerator of this type according to the present invention, and FIG. 2 is a schematic configuration explanatory view showing another embodiment of an absorption refrigerator of this type according to the present invention. Is. (1) …… Generating condenser, (2) …… Evaporation absorber, (G) …… Generator, (C) …… Condenser, (E) …… Evaporator, (A) …… Absorber,
(11), (12), (13), (14) …… heat exchanger, (J) …… jacket, (17), (18), (19), (20), (21) …… tube , (P _C) ...... cooling water pump, (V ₂₎ ...... flow rate control valve, (C _R) ...... _{controller, (S 1), (S} 2), (S 3), (S 4) ……Detector,
(24) …… Pipe, (V ₃ ) …… Three-way valve.

Claims (7)

[Claims] 1. A device such as a generator, a condenser, an evaporator, an absorber, a solution heat exchanger and a pump for absorbing liquid is connected by piping to form a refrigerant circulating passage and an absorbing liquid circulating passage. In an absorption refrigeration machine that uses a fluid flowing out from the equipment side such as a rectification tower of a chemical plant as a heating source of a generator and then returns it to the equipment side, and makes a cooling fluid flow through an absorber and a condenser. A detection mechanism that detects physical quantities related to changes in the refrigeration cycle or a timer that stores a program for controlling the flow rate of the cooling fluid at startup,
An absorption refrigerator comprising a detection mechanism or a control mechanism for gradually increasing a cooling fluid supplied into the machine from a small amount during a period from startup to a normal operation by a signal of a timer. 2. The absorption refrigerator according to claim 1, wherein the detection mechanism is a temperature detector provided in a flow path of a fluid returning from a generator to the facility side. 3. A temperature detector provided in the flow path of the cooling fluid flowing out from the condenser, wherein the detection mechanism is a temperature detector.
The absorption refrigerator according to the item. 4. The absorption refrigerator according to claim 1, wherein the detection mechanism is a temperature detector provided in the absorbing liquid in the generator. 5. The absorption refrigerator according to claim 1, wherein the detection mechanism is a liquid level detector provided in a refrigerant liquid reservoir of an evaporator. 6. The controller according to claim 1, wherein the control mechanism is a controller that adjusts a discharge amount of a pump or an opening degree of a flow rate control valve provided in a flow path of cooling water flowing into the absorber. Absorption refrigerator. 7. The absorption refrigerator according to claim 1, wherein the control mechanism is a controller that adjusts an opening of a flow control valve provided in a flow path of cooling water that bypasses the absorber.