JPS5896963A - Controller for 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 The present invention relates to flow control of refrigerant or absorption liquid in a relatively small absorption refrigerator.

Although some parts of absorption refrigerators use liquid pumps to circulate the refrigerant and absorption liquid, there are fewer parts that use pressure differences and head differences between each component part to ensure liquid flow. In particular, in small absorption refrigerators, there are many parts that use pressure differences and head differences to circulate the liquid, and do not use pumps, but only pressure differences or ~rad differences (-therefore, liquid circulation is ensured. There are also natural circulation absorption refrigerators.

However, liquid circulation due to such a pressure difference and head difference C2 becomes stable only when the temperature and pressure conditions of all components of the absorption chiller reach a steady operating state. After startup, the steady operating state (until - (at startup), or before stopping the operation of the absorption chiller, reduce the absorbent concentration in each part (during dilution), or when the absorption chiller starts and stops. During so-called unsteady conditions, such as during repeated partial loads, liquid circulation is not performed smoothly C2, and the liquid is unevenly pressured in each component of the absorption refrigerator.As a result, the absorption liquid mixed in the refrigerant circulation circuit and the test liquid pump This results in various problems such as cavitation and dry firing in the 8-generator.

In view of this, the present invention provides a control valve in the refrigerant circulation circuit or the absorption liquid circulation circuit, and adopts a configuration in which the @ control valve is opened and closed according to the absorption liquid level in the separator. The purpose is to completely control the liquid circulation of the chiller 5E machine, and to eliminate problems such as absorption liquid mixed into the 6 second generation refrigerant during so-called unsteady conditions such as during start-up, and to ensure safe operation of the chiller. It is something.

An embodiment of the present invention will be described below with reference to the drawings.

The drawing shows an example in which the invention is implemented in a small double-effect absorption refrigerator. (1) is a high-speed refrigerant that heats and separates the refrigerant from a dilute liquid using a saline gas such as kerosene and regenerates it into an intermediate liquid. ! Nyuuki,
(2) is heated by the high temperature regenerator (1) and the liquid lift pipe (31
A separator that separates the intermediate liquid and refrigerant vapor that have risen from the
4) is a low-temperature regenerator that further heats and separates the refrigerant from the intermediate liquid using the heat of the refrigerant vapor from the fractionator (2) and regenerates it into a concentrated liquid;
(5) is a condenser that condenses and cools the refrigerant from the regenerator fil (4); (7) is an evaporator configured to obtain cold water for air conditioning from the evaporator;
Two refluxing bubble pumps (9) are connected to the low temperature regenerator (4);
) A heat recovery device that raises the temperature of the dilute liquid with refrigerant from Q In order to maintain a low pressure inside the evaporator (6) and to provide a continuous supply of cold water, there are two absorbers, I and Caa low temperature and high temperature solution heat exchangers, which are connected to the refrigerant vapor pipe U, the refrigerant Liquid flow down pipe 14
1. Tank liquid pipe α with refrigerant circulation path α9 and dilute liquid pump αe
It has a supplementary fluid side pipe q#, an intermediate liquid supply α field, a concentrated liquid pipe (4), and an on-off valve (to) to open the on-off valve during heating. The refrigerant vapor is connected to the evaporation absorption cylinder @C together with the absorption liquid through a bypass pipe (c) which allows hot water to be taken out from the heat exchanger (7), thereby reshaping the circulation circuit between the refrigerant and the absorption liquid.

(Incorporated) is the intermediate liquid control valve installed in the intermediate liquid tU9, (c) is the side path intermediate liquid control valve installed in the side path pipe (to) of the intermediate liquid pipe 0, and @ is the intermediate liquid control valve installed in the intermediate liquid pipe 0. Pipe 0ηC: Provided replacement fluid control valve.

(To) is the refrigerant control valve installed in the refrigerant vapor pipe 03 on the way from the separator (21 to the condenser (5)), ■ is the separator (2) gatekeeper = installed liquid level, @ Goki, According to the signal from the controller, the intermediate liquid control valve C2J, 11!Circuit intermediate liquid control (
The valve (c), replacement fluid control valve +27), or refrigerant control valve (g) is operated to open or close.

Next, the operation and control operation of the embodiment of the present invention will be explained.

(a) Operation at startup When starting the absorption chiller, high-temperature regeneration i! 5 (11, Separator (
Since the temperature and pressure inside the separator (2) are lower than normal and the pressure difference between the separator (2) and the low-temperature regenerator (4) is small, the flow of the intermediate liquid is poor and the liquid level inside the separator (21) gradually rises. Then, in response to the rise in the liquid level in the separator (2), the liquid level controller
2) The intermediate liquid control valve @ and the side route intermediate liquid control valve (to) are opened to a large degree, the test liquid control valve (b) or the refrigerant control valve (
Make it as small as possible. By fully opening or increasing the opening of the intermediate liquid control valve (24) and the side route intermediate liquid control valve (c), the flow of the intermediate liquid becomes smooth and the flow of the intermediate liquid in the separator (2) ((a)
The intermediate liquid flows from the separator (2) to the low-temperature regenerator (4) via the separator (2), thereby preventing an abnormal rise in the liquid level in the separator (21).

], refrigerant→J control valve C& is fully opened or opened to a small degree, thereby preventing the absorption liquid from entering the refrigerant circulation circuit from the separator i21 [particularly, the absorption liquid of the separator (2) This prevents the surface from rising abnormally and causing a large amount of absorption liquid to flow into the refrigerant circulation circuit. ]. Cavitation of the diluted liquid pump αe is also prevented by reducing the opening degree of the diluted liquid control valve. In other words, in the conventional absorption refrigerator, at startup, the amount of absorbed liquid ME entering from the separator (2) to the absorber O1 is small, while the amount of absorbed liquid flowing out from the absorber to the high temperature regenerator (1) is small. Since the diluted liquid pump tttp performs the same operation as in normal operation, there is a risk that the absorbed liquid in the absorber QCJ will gradually decrease and cavitation Z will occur in the diluted liquid pump αe, and the flow of the diluted liquid will stop due to the cavitation of the pump. Finally, the g of the high temperature regenerator (1)
! There was a risk of ignition, but it was resolved by increasing the opening of the intermediate liquid control valve @side route intermediate liquid control valve (G)! ! <While increasing the absorption liquid inflow 11 to IQ, the opening of the tank liquid control well Qη is made small to reduce the absorption liquid outflow it from the absorber σ.≦2. Cavitation of the replacement liquid pump haze is prevented. In addition, dry firing of the high temperature regenerator (1) is also prevented.

These control valves cl! 41 (to) (b) or (to) are operated at the same time when the liquid level in the separator (2) detected by the liquid level controller (to) reaches a level. Also, depending on the rise in the liquid level in the separator (2), for example, tank liquid control valve (capital) → intermediate liquid control valve@
It is also possible to operate these control valves sequentially, such as by changing the opening degree and setting in the order of the intermediate liquid control valve (to) and the refrigerant control cape valve.

Therefore, when starting up the absorption chiller, operation is carried out safely, the pressure and temperature inside each component are brought to a tight state, and the absorption liquid and As refrigerant circulation became smoother, separators (
2) The liquid level inside begins to drop.

Then, the liquid level in the separator (2) decreases (in response, the intermediate liquid control valve Q is activated by the signal from the liquid level side device 03, and the opening degree of the side route intermediate liquid control valve (c) is reduced, and the tank liquid Operate the control valve (C) and refrigerant control valve (to) to a large opening (C: to -), and open the separator (
2) When the internal liquid level reaches the set value, that is, when the steady state is reached.

The so-called steady operation is performed with the intermediate liquid control valve 124) at the set opening, the sideway intermediate liquid control valve (c) fully open, and the tank liquid control valve @ and the refrigerant control valve fully open. In this way, the present invention improves liquid circulation by operating the control valve (to) (to) (to) (b) or (sub) according to the liquid level in the separation Wi (21) and achieves steady operation safely and in a short time. (improved startup characteristics).

(Operations during dilution of CFl In general, an absorption refrigerator (2) is operated by stopping the heating to the regenerator, and by operating the absorption liquid pump, etc., to reduce the concentration in each equipment such as the solution heat exchanger. A so-called dilution operation is performed to dilute the liquid and prevent crystallization of the absorbed liquid when the refrigerator is completely stopped.

Therefore, when the heating to the high temperature regenerator (1) is stopped, the pressure and temperature inside the separator (2) rapidly decreases, and the temperature between the separator (2) and the low temperature regenerator (4), etc. The pressure difference becomes smaller,
Similar to the above-mentioned case B1, the liquid circulation deteriorates and the liquid level in the 1st separator (2) rises. During such dilution, depending on the rise in the liquid level in the separator (2) at C2, the opening of the control valve (24t25 is increased, and the opening of 2M is decreased. The liquid circulation becomes difficult and it is safe in a short time (two concentrated liquids are diluted (improved dilution characteristics).

(c) Operation during partial load In general, in small absorption refrigerators, it is customary to perform so-called on-off control that repeatedly turns on and off heating to the regenerator when the partial load is off. The start-up standby operation and dilution operation are repeated.

Considering this, when starting heating to the high-temperature amphigenator (1), the above-mentioned K)
When starting up - the same control as in the second stage, and when heating is stopped, perform the same control as in the above-mentioned dilution (in the second stage) to ensure that the liquid circulation at 1 partial load is good≦2 and safe≦
Operate dual absorption refrigeration m.

Note that in order to achieve the object of the present invention C; the refrigerant control valve @
It may be controlled by detecting the pressure or temperature in the separator (2), but it is better to detect the liquid level in the separator (2) because the liquid circulation state can be directly known, and the liquid circulation @ control can be conducted more appropriately.

As described above, the present invention connects the regenerator 1 separator, condenser, evaporator, absorber, and solution heat exchanger with piping to form a refrigerant circulation circuit, an absorption liquid circulation circuit, and the refrigerant circulation circuit or A control valve is provided in the absorption liquid circulation circuit, and the opening degree of the control valve is controlled according to changes in the absorption liquid level in the separator to improve liquid circulation during so-called unsteady conditions such as during startup and dilution. Therefore, it is possible to ensure safe operation of the absorption refrigerator and to realize the same so-called starting characteristics and dilution characteristics.

Although the embodiment shown in FIG. 1 has been described with reference to a double-effect absorption chiller C, it goes without saying that the present invention can also be implemented in a single-effect absorption chiller.

[Brief explanation of the drawing]

Drawing 11 is a circuit configuration explanatory diagram of an embodiment of the present invention. (21-...Separator, (To)...Intermediate liquid control valve, (C)--Sideway intermediate liquid control valve, (1)...Sideway pipe, 12n
@One-tank liquid, refrigerant system (company) valve. (c)...Liquid level detector.

Claims (1)

[Claims] (1) A refrigerant circulation circuit in which a regenerator, a separator, a condenser, an evaporator, an absorber, and a solution and liquid heat exchanger are connected through piping. An absorption refrigerator characterized in that an absorption liquid circulation circuit is formed and the circuit is provided with two control valves, and the opening degree of the control valve is controlled according to a physical quantity such as a liquid level in the separator. (2) A control device for an absorption refrigerating machine according to claim 1, in which the control valve is connected to a test liquid circuit (2) extending from the absorber to the regenerator. t. Control of an absorption refrigerating machine according to claim 1, which is provided in an intermediate liquid bypass circuit arranged so that the intermediate liquid bypasses the solution heat exchanger and leads from the separator to the low-temperature regenerator. (4) The control device for an absorption refrigerating machine according to claim 181, wherein the control valve is provided in a refrigerant vapor circuit extending from a separator to a condenser.