JPS6273054A - Absorption refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to an improvement of an absorption refrigerator (hereinafter referred to as this type of absorption refrigerator) equipped with a solution flow rate adjustment device and a heating amount adjustment device.

(B) Conventional technology The conventional technology for this type of absorption refrigerator is as follows: 1. As seen in Japanese Patent Publication No. 58-34730 and Japanese Patent Publication No. 59-52348, there is a method for sensing the cold water outlet temperature of the evaporator. There is a known method that proportionally controls a dilute solution flow rate control valve and a generator heating amount control valve (hereinafter referred to as the former) via a temperature controller (and potentiometer) based on a signal from a temperature sensor. In addition, as another conventional technology for this type of absorption refrigerator, a heating amount control valve is controlled according to the cold water outlet diopter of the evaporator, while a dilute solution flow rate control valve is controlled according to the cold water outlet temperature of the evaporator. Kaikai - ``rumono [for example, special public service in 1972-
No. 35342] (hereinafter referred to as the latter) is known.

9→ Problems to be Solved by the Invention In both the former and latter type of conventional absorption refrigerators described above, the heating amount control valve is proportionally controlled based on the cold water inlet temperature, which has a direct influence on the refrigeration output. Therefore, it has the advantage of being able to control the amount of heating so that the refrigeration output matches the load. However, the operation of controlling the amount of heating is a proportional operation [P operation], and there is a proportional band of the chilled water outlet temperature, so this temperature depends on the load. It has the disadvantage of fluctuating with changes. For this reason, this type of conventional absorption refrigerator has the problem that it is not suitable as a refrigerator for use in facilities that require cold water at a constant temperature, such as clean rooms and chemical process facilities. In addition, the former has the advantage of being able to adjust the amount of diluted liquid supplied to the generator to match the heating amount of the generator.
In addition to the latter'Mako's advantage, fuel usage rate I! Advantage of being lower than 1'-? However, these both adjust the amount of dilute liquid supplied to the generator, and do not adjust the amount of concentrated liquid supplied to the absorber, which has a direct effect on the refrigeration output, so sudden changes in load may occur. (For example, when the number of clean room operations is drastically reduced or increased), the control has poor follow-up ability, and it is difficult to stably supply cold water at a predetermined temperature to the load side. There is. In addition, a flow control valve was installed in the ill liquid flow path. It has been proposed, for example, in Japanese Patent Laid-Open No. 59-44557, to adjust the amount of concentrated liquid supplied to the absorber by controlling the amount of concentrated liquid supplied to the absorber.

In this case, the pressure difference between the generator side and the absorber side is 6"
- If the amount of concentrated liquid supplied to the absorber does not change much, it is difficult to rapidly increase the amount of concentrated liquid supplied to the absorber, so there is a problem that the control ability to follow a sudden increase in load is poor. In view of this, it is an object of the present invention to provide an absorption refrigerating machine of this type which is excellent in followability of refrigerating output control to the load and is capable of supplying chilled water at a predetermined temperature to the load.

(-1 Means to Solve the Problem) The present invention, as a means to solve the above problems, adjusts the solution flow rate of this type of absorption cooling fi machine by the signal from the detector of the cold water inlet temperature of the evaporator. It is configured to control the discharge amount of the concentrated liquid pump, and the heating amount of one generator is adjusted by PI control of the heating amount based on the signal from the detector of the cold water outlet temperature of the evaporator [control by proportional action + integral action] ] or PID control (control based on proportional action + integral effect and sufficient differential).

(4) Function This heel absorption refrigerator according to the present invention has a function to adjust the amount of concentrated liquid supplied to the absorber and the discharge rate of the pump for concentrated liquid, which directly affects the refrigerating output. Since there are two functions, it is excellent at following refrigeration output control.

In addition, there is a function that controls the discharge amount of the concentrated liquid pump according to the population temperature of chilled water (or cold air), which is directly affected by changes in load, so it is possible to adjust the refrigeration output to match the load. becomes. Gah.

Determination of chilled water outlet temperature; Temperature inside the evaporator and absorber during the night; amount of heating that affects absorption liquid concentration [i.e. concentration level of absorption liquid], which affects saturated vapor pressure; Detection of chilled water outlet temperature; This type of absorption refrigerating machine has a function of maintaining the chilled water outlet temperature at a target value, since this is carried out in response to a signal from the refrigerator via a PI regulator or a PIDa 14-section regulator.

(f) Example Is Figure 1 an example of this type of absorption refrigerator according to the present invention?
FIG. 2 is a diagram schematically illustrating the configuration. In Figure 1, (1)
I. High @ generator, (2) is low @ generator condenser consisting of generator (3) and condenser (4), (5) is evaporator (6)
and an absorber (evaporative absorption J (81, (9)) are low-temperature and high-temperature bath liquid heat exchangers, respectively (101 is an absorber (
7) dilute acid reservoir, old) is f4i night reservoir aO) overflow avr: concentrated liquid reservoir with, 03) is solution sprayer, (14
)'・Ma evaporator (6) refrigerant liquid reservoir, U Zheng i refrigerant liquid sprayer, (PL, ) is pump for dilute acid, (P, □) is pump for concentrated liquid, (P7) is for refrigerant liquid In the pump, these are the pipes (16), (17) through which the refrigerant flows, the 'd+ through which the refrigerant liquid flows
廀、Refrigerant liquid reflux pipe u9、Side、Dilute liquid sent pipe (
2υ, vessel, Cshi, (2(a), pipe vessel through which the intermediate liquid flows,
4. Concentrated liquid flowing down pipe ■, CL concentrated liquid flowing pipe I2t
, (2) are connected to form a circulation path for the refrigerant (water) and the absorption liquid (odor-rich hylithium aqueous solution).

01) is the combustion heating chamber of the high temperature constant generator (1), G2
... is the pipe through which combustion gas flows, (to) is the low @ generator (3
) is the PA adder, (b) is the condenser (4) cooler, (to)
is the heat exchanger of the evaporator (6).

06) is a cooler for the absorber (7). Also, C37)
, (to) is the load side heat exchange unit [not shown] and the heat exchange Masuda? The tied conduit, G! J, (4G, (41
) is the cooler □□□, (b)? Air supply line connected in series,
This is a fuel supply line that connects the fuel tank (not shown) to the fuel tank (not shown). The air supply path (4z) and the fuel supply path (c) are each equipped with a damper (Dl) and a fuel control valve (2).

In addition, (Vl), CV, ), and (V3) are the pipe (44) connecting the pipe a and the evaporator (5), and the pipe (ha) connecting the pipe a and the pipe (21), respectively. ), refrigerant reservoir ■ and pipe? These cold/hot switching valves are closed during refrigeration operation. When these cold/hot switching valves are opened and operated, hot water (or hot air) can be obtained from the heat exchanger 65. In such a case, cut off the flow of cooling water (or cooling air) to pipes C3'J, (4G, (41)) and stop the operation of the refrigerant liquid pump (8) and concentrated liquid pump (Pl, , ). (47) is a pipe for blowing refrigerant liquid, and a non-open/close valve (Vl) 6- is attached to this pipe.
(S eXW ) is the heat exchanger (S eXW ) that flows out of the cold water [cold air] = -1 The temperature of the hot water [warm air] (hereinafter referred to as the cold water outlet temperature)? A detector that senses the PI or PID regulator (CvI) based on the signal from this ejector.
) through damper 1D) and fuel! ! 11 Moaning valve (V
, ) is controlled by the opening Y(ut).Adjustment 5
When a PI regulator is used for (Cvo), the control operation of this regulator is shown by the following (Equation 81).

M=100/P(e+1/T1・fedt)...
・・・・・・・・・(a) In addition, (in the a+ formula, M-ma operation amount [damper CD) and! Opening degree IP' of 2-way control valve (v2) = strength of proportional action? The constant representing [also referred to as the proportional band] 100/P'' is the proportional gain, and e is the deviation [also referred to as the control deviation or control operation signal. It means the difference from V.], T is a constant (also called integration time) that represents the strength of integration.

Also, if a PID regulator is used as the regulator (CYD),
The control operation of this regulator is expressed by the following equation tb).

M=100/P(e+1/TI-fedt+TD-de
/dt)...(b) In addition, in fbj2, T, i
The strength of the differential is expressed by the constant, which is called the differential time. Other symbols <1 (same as formula 81. These (a),
(As shown in equation b1, the opening degree M [operated amount] of the damper (D+ and fuel control valve (V)), the difference e [control deviation] of the chilled water outlet temperature X with respect to the target temperature V of the cold water outlet, and the time It becomes a function with t and ? variables.

(Senw) +-z A detector that senses the temperature of cold water (cold air) flowing into the heat exchanger Masuda from the load side heat exchange unit (not shown) (hereinafter referred to as cold water inlet temperature), and the signal of this detector The discharge amount of the concentrated liquid pumps (P, A) is proportionally controlled through the adjustment 6 (C□,).

(SaA) - This is a detector that senses the temperature of the absorption liquid of the home high temperature generator (1), and the signal from this detector is used to control the regulators (C,
The discharge amount of the dilute acid pump (PL, ) is proportionally controlled through the pump L□). Furthermore, (I,).

(Engineering) is an inverter. Next, an absorption chiller (hereinafter referred to as "absorption refrigerator") configured in this way will be described.

An example of the operation of this machine (referred to as this machine) will be explained in relation to the control operation of '@Iso.
°C, regulator (C, ,) d', i proportional band p b:
s℃ to 20'C1 Integral time T, 6'' - 5 minutes to 10 minutes, Differential time T. PID ID controller that can be set to 11 minutes to 15 minutes. When the temperature reaches 12℃, the concentrated liquid pump (P
, , ), while setting the discharge amount to the maximum [100%]
When it reaches °C, use Centosu Motsu for zero [O%],
In addition, the regulator (C, I) has 1 and the house price generator (1).
When the temperature reaches 150℃, the discharge rate of the dilute acid pump (PL) is set to the maximum [100%], and when the temperature reaches 140℃, the maximum discharge rate is 1151m20%.
] What to sect? A case in which it is used will be explained. In this case, the load is zero (0%) when the chilled water inlet temperature reaches 7°C, which is the target temperature of the chilled water outlet, and the load becomes 100% when the chilled water inlet temperature reaches 12°C.
%.

Now, while the machine is operating, 1 For example, the load changes from 100% to 50%.
When the refrigerating capacity (refrigerating output) of this machine suddenly decreases, the cold water of approximately 7°C flows from the heat exchanger C35+ because it does not change suddenly.
Supplied to the load side. On the other hand, since the load has been halved,
The temperature of the cold water flowing from the load side into the heat exchanger (chilled water inlet temperature) begins to drop.

As a result, the concentration pump (P, □
) is gradually reduced as shown in FIG. In addition, Fig. 2 shows the relationship between the chilled water inlet temperature Y [chilled water load RE (displayed on the horizontal axis) and the discharge tM of the concentrated liquid pump (P, .) (displayed on the vertical axis). FIG. MP, I as shown in FIG.

is proportionally controlled from 100% to 50% of its maximum value, the flow rate of concentrated liquid distributed to the cooler (to) of the absorber (7) is proportionally reduced, and the The amount of refrigerant absorbed gradually decreases. That is, the absorption capacity of the absorber (7) is adjusted so that the refrigerating output matches the load.

By the way, the drop in chilled water inlet temperature Y due to a sudden decrease in load -
1. When viewed on a second-by-second level, the drop in Y becomes more gradual. ], and as a result, the absorption capacity of the absorber (7) also becomes slower to adjust, so the concentrated liquid pump (P+
! Even if the discharge amount MPIIA in A) starts to be adjusted, the state of excessive refrigerating output will continue for a while (particularly until MPIIA is fixed at 50%) in response to the rapidly reduced load. For this reason.

Heat exchanger Tauchi's heat exchanger b' - will be excessively cooled, and the seismic intensity of the cold water flowing out (chilled water outlet temperature X) will also begin to drop. As a result, the opening degrees of the damper ID) and fuel control valve (v7) are controlled by No. 1 of the injector (S-xw) through the adjustment B (CvD) for PID control @, and the opening of the high temperature generator ( 1) The heating amount b'- is adjusted. In addition,
The opening degrees of the dampers f, D) and the fuel control valve (■2) [can be obtained from the above 2(a)], control deviation e, that is, the target temperature of the chilled water outlet (7°C) and the chilled water outlet temperature X Since the difference between the two values changes from moment to moment for a while, it must remain constant during this time.

In this way, immediately after the load suddenly decreases, the concentrated liquid pump (P11 □
), the proportional control of the discharge amount M□, is started, and there is a slight delay from this control [about 1 to 2 seconds delay, which is such a delay that a human being can feel it almost at the same time. ] PID control of the opening of damper fD) and fuel control valve (v2) is started, and the heating input of the machine is adjusted so that the refrigeration output matches the load, and the heat balance of the machine is balanced. It will be maintained.

And, as shown in Figure '@3, the cold water outlet diopter X is almost maintained at the target temperature, and the cold water population temperature Y is also 95 degrees Celsius.
(see figure), when M□ and U are fixed at 50%, the above opening degrees are also almost fixed, and the control ends. In addition,
FIG. 3 is a diagram showing momentary changes in the chilled water outlet temperature X with respect to changes in the chilled water load R (control progress) in PID control. In FIG. 3, the horizontal axis shows time t, and the vertical axis shows changes in the load R as a disturbance and changes in the cold water outlet temperature X as a deviation.

In addition, in one machine, the temperature and saturated vapor pressure of the absorbing liquid in the generator (1) begin to drop as the heating capacity is reduced to match the suddenly reduced load, and as a result, the Since the amount of absorption liquid flowing from the @generator (1) to the low @generator (3) side begins to decrease, the signal from the detector (S, , ) causes the controller (Cvt,) for proportional control to The discharge amount of the fluid replacement pump (PL) is gradually reduced as shown in FIG. In addition, Figure 4 shows the absorption liquid gain Z within 5 m of high @ occurrence.
What is the relationship between and the discharge amount MpL of the replacement fluid pump (PL, )?
The diagram shown is the discharge of the saliva pump (PLA).
AMp1. By reducing A, the amount of absorption liquid in and out of the high temperature generator fl+? This makes it possible to balance the temperature of the absorbing liquid, and also to save on significant consumption due to the temperature increase of the absorbent. The opposite action will take place.

In this way, when the machine is in use, it becomes difficult to respond to changes in load.
(The pump for concentrated liquid (P
By controlling the discharge K M p II Ak of □, ), the amount of concentrated liquid sprayed to the absorber (7) is adjusted.
absorption capacity? By controlling the heating amount of the high-temperature generator (1) according to the load, the amount and concentration of concentrated liquid applied to the absorber (power) can be adjusted indirectly to the absorber (7).
absorption capacity? Compared to the conventional one to be adjusted.

Is the response speed of the refrigeration output to load changes faster? As long as it continues, high @ generator (1), generation condenser (2)
, the pressure difference between the evaporator and absorber (5)? Motsunoso absorber (7)
There is a limit to the ability adjustment of the absorber (7) to cut off the spraying of concentrated liquid to the absorber (7). On the other hand, this machine has a concentrated liquid pump (P,
,) the capacity of the absorber (7) by stopping Y? Since the refrigeration output can be completely lost, the control range of the refrigeration output can be expanded compared to the conventional method. In addition, absorption from low @ 箆生器(3)
It is also possible to cut off the spraying of the concentrated liquid to the absorber (7) by providing a valve in the concentrated liquid flow path leading to the solution spraying 5 (13) of l'1 (1) and completely closing it. In this case,
When the load suddenly increases, the valve is fully opened and at the same time the high @ generator (1
) Even if the heating amount of It is not possible to increase the amount rapidly. However, this method (C) also has the disadvantage of poor followability of the refrigerating output when the load suddenly increases. On the other hand, in one machine -1, m liquid pump (P,,)
Discharge amount MPI1. By rapidly increasing the refrigeration output, it is possible to quickly overturn the refrigeration output to match the rapidly increased load. In addition, in this machine, by making the capacity of the liquid reservoir uD sufficiently large, the discharge amount M of the concentrated liquid pump (P, ) can be increased.
, 3. Of course, cavitation can be prevented in the event of a rapid increase in M□A.Also, in the event of a sudden decrease in M□A, the flow from the concentrated liquid reservoir CILI to the dilute acid reservoir qO s MpI because it can discharge concentrated liquid! By controlling it to 1, it absorbs 1 night flow and supports 11! There's nothing like it happening.

Furthermore, this book [How many times is it '4, cold water outlet compatibility X? While detecting the amount of heating of the high temperature generator (1) by the PID operation of the damper (Dl of the air supply path (42) and the fuel control valve (V), the degree of concentration of the absorption liquid is adjusted. It is possible to maintain the saturated vapor pressure and saturation temperature of the concentrated liquid sprayed in the cooler of the absorber (7) within a predetermined range, and also to maintain the chilled water outlet temperature approximately at the target temperature V (7°C). ″】
It is also possible to use a VCli, and a liquid pump (
It is also possible to balance the heat balance of the machine by increasing or decreasing the heating input of the machine in response to the increase/decrease in the refrigerating output by controlling the discharge amount M, □ of P, □). 5 In this machine, 1, Danno: -+rn and fuel control valve (
The amount of heating may be adjusted four times by the PI operation of V, ). In the case of adjustment by PI operation, compared to the case of adjustment by PID operation, hunting in the chilled water outlet temperature X becomes transiently somewhat larger when the chilled water load R suddenly changes.

This degree of hunting can be ignored [particularly when adjusting the heating amount of a large-capacity absorption refrigerator, there is no significant difference in the degree of hunting. ].

In addition, in this machine, the discharge amount MPL of the dilute acid pump (PL) is detected while detecting the absorption liquid temperature Z of the high temperature generator (1).
picture? Since it is controlled, is the balance of the absorption liquid in and out of the 5-high @ generator (1)? Keep the absorption liquid circulating? It is possible to maintain good thermal efficiency and maintain a high level of thermal efficiency.It is also possible to operate with hot water from the MPLA system heat exchanger field.

Furthermore, in this machine, the detector (SenW), (Se
xw), (SGA)%'! , the conduit G7), (to), and the wall of the specific generator (1) may be sensed.

(G) Effects of the Invention As described above, according to the present invention, the ability of the current freezing output control to follow sudden changes in load? The control range can be expanded as well as the suction ff16. Saturation temperature inside the evaporator? This type of absorption refrigerator can bring excellent effects that are difficult to achieve with conventional absorption refrigerators, such as being able to keep the cold water outlet temperature constant within a predetermined range. It goes without saying that the same effect can be achieved even if a heavy-effect absorption refrigerating machine is applied.

[Brief explanation of drawings]

Is this kind of absorption according to the present invention the first example? The schematic configuration explanatory diagram shown in Figure 2 “・Cooled water inlet temperature Y
and cold water load R and Wλ liquid pump discharge amount M, IIA
Figure 3 is a graph showing the change in chilled water outlet temperature It is a diagram showing the relationship between the discharge amount Mp and L of the acid pump. (1)...High temperature generator, (2)...Generation condenser, (
3)...low temperature generator, (4)...condenser, (5
)...Evaporator absorber, (6)...Evaporator, (7)...
・Absorber, (8), (9)...Low temperature, high temperature @ belly heat exchanger, (10)...Dilute acid reservoir, UL)...Concentrated liquid reservoir, (121+...Offflow port , 03)...Solution sprayer, CD, container, container, C241, field, 06J, @
, (2), GO)...pipe, C3+)...combustion heating chamber, ■...heater, (b)...cooler,
Field...Heat exchanger, ■...Cooler, (3η, (to)...Pipe, (4)...Air supply path, (4J・
・・Fuel supply path, < pL, )−1° fluid replacement pump, (P,, )・・concentrated liquid pump, (Senv
)...Detector, (C□,)...Adjuster. (Sc,)...Detector, (CV,)...Adjuster, (D)...Damper, (V,)...Fuel control valve Applicant Sanyo Seiki Co., Ltd. and one other representative Person Patent Attorney Shizuka Sano Arrow 2 Figure 7 g 4 10 11 12'ζ4, enter Roshishi Sei (A) Figure 3

Claims (4)

[Claims] (1) A variable discharge volume pump is provided in the flow path of the concentrated solution, and a concentrated solution flow rate adjustment device that controls the discharge volume of this pump by the temperature of the cold water inlet of the evaporator and the amount of heat generated by the generator are controlled by the cold water of the evaporator. An absorption refrigerating machine characterized by being equipped with a heating amount adjusting device that controls the outlet temperature. (2) The absorption refrigerator according to claim 1, wherein the control operation of the concentrated solution flow rate adjustment device is a proportional operation. (3) The absorption refrigerator according to claim 1 or 2, wherein the control operation of the heating amount adjusting device is a PID operation. (4) The absorption refrigerator according to claim 1 or 2, wherein the control operation of the heating amount adjusting device is a PI operation.