JPS60126559A - 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 (a) Industrial Application Field The present invention is applicable to dual-effect absorption refrigerators and absorption heat pumps (
The present invention relates to a control device that adjusts the amount of liquid in a high temperature generator of an absorption refrigerator (hereinafter referred to as an absorption refrigerator).

(b) Conventional technology In dual-effect absorption refrigerators, if the liquid level in the high-temperature generator becomes too high, the absorption liquid mixes with the refrigerant vapor generated within the container due to heating, reducing the refrigeration effect. At the same time, the level of the suction liquid in the pump that sends the absorption liquid drops, causing cavitation in the pump.For this reason, conventional high-temperature generators are equipped with an electrode-type liquid level relay, and this relay detects the liquid level and absorbs the liquid. Starting and stopping liquid pumps, or
By controlling the valve as described in Japanese Patent No. 43216, the amount of absorption liquid sent to the high temperature generator is adjusted to prevent the liquid level from rising excessively.

In an electrode type liquid level relay, generally, as shown in Fig. 1, the sensor part (a) of the liquid level relay is located at the junction between the wall (b) of the absorption liquid tank and the electrode (d). is an insulator (for insulation), and a bolt (
The sensor part (a) of the liquid level relay is attached to the tank by fitting the gl and screwing this bolt into the wall (b)1, which may cause vacuum leakage from the joint. This has the disadvantage that it easily interferes with the normal operation of the absorption chiller.

Furthermore, since the surface of the electrode (d) corrodes or becomes dirty due to the influence of the absorbing liquid (for example, lithium bromide aqueous solution), there is also a drawback that the liquid level relay is likely to malfunction.

Furthermore, if the insulator (f) gets wet with the absorbing liquid or refrigerant, it will cause insulation failure, making the liquid level relay more likely to malfunction.

(C) Object of the Invention The object of the present invention is to provide a control device that can reliably prevent an excessive rise in the level of filtrate in a high temperature generator of an absorption refrigerator without causing malfunction.

2) Structure of the Invention The present invention provides a pipe (hereinafter referred to as overflow (referred to as a tube) is connected between the high temperature generator and the low temperature generator,
A first temperature measuring element is provided at an appropriate location in the overflow pipe, and a second temperature measuring element is provided on the liquid reservoir side of the high temperature generator, and when the difference between the temperature values of these temperature measuring elements becomes less than a predetermined value, a high temperature is generated. The structure is such that the flow of absorption liquid into the container is blocked.

When a temperature measuring element is provided in this way, when the normal operation of the absorption refrigerator is maintained and the liquid level of the high temperature generator is within the normal level range, the temperature measuring element of the first temperature measuring element is activated. The difference between the temperature measurement value of the second thermometer and the first thermometer, which shows a value close to the temperature of the absorbing liquid inside, is about 20 degrees Celsius, but for some reason a high temperature has occurred. When the liquid level in the vessel rises and the absorption liquid begins to flow in the overflow pipe, the temperature measured by the first temperature measuring element also shows a value close to the temperature of the absorption liquid. For example, it becomes about l'C, and there is almost no difference.

Therefore, according to the present invention, a rise in the liquid level within the high temperature generator can be accurately detected, and an excessive rise in the liquid level can be reliably prevented.

Furthermore, according to the present invention, there is no need to insert a part of the sensor of the temperature measuring element into the absorption liquid or into the overflow pipe, so there is less possibility of malfunctions as in conventional electrode type liquid level relays.

(E) Embodiment FIG. 2 is a schematic configuration explanatory diagram showing an embodiment of the control device for an absorption refrigerator according to the present invention, in which (11 is a high temperature generator, (2 is
) is a low temperature generator, (3) is a condenser, (4) is an evaporator, (
5) is an absorber, (6), (7) is a solution heat exchanger, (8)
is a pump for absorption liquid (hereinafter referred to as solution pump), (9
1 is a refrigerant liquid pump, and these devices include refrigerant flowing pipes (10), 00), refrigerant liquid flowing down 1-filtration pipe (11)
, refrigerant liquid reflux pipe (121, (+2), replacement liquid (7)
R;h Le tube Q31. (131, pipe 04 through which the intermediate liquid flows), (+4), pipe (+5) through which the concentrated liquid flows, and are connected by a9 to form a circulation path for the refrigerant and the absorption liquid.

Note that the replacement fluid refers to an absorption solution with a low absorbent concentration, the concentrated solution refers to an absorption solution with a high absorbent concentration, and the intermediate solution refers to an absorption solution with an absorbent concentration between that of the replacement solution and the concentrated solution.

(16) is the heat supply for the high temperature generator (1), On is the heater for the low temperature generator (2), f181.0], (20) is the condenser (3), evaporator (4), and absorber, respectively. (21), CD is a pipe through which the heat source fluid flows, connected to the heat supply device θG), C22, C2 is the heat exchanger 0
5. A pipe through which cold water or a low-temperature heat source fluid flows, connected to the power source (23), □□□ is a heat exchanger (20), and a pipe connected in series to the heat exchanger (20), which is a pipe connected in series to a pipe to be heated such as cooling water or hot water or hot air. A tube through which fluid flows. In addition, (■ is a valve provided in the pipe (2I).

at a position higher than the normal level of the liquid level in the high temperature generator (1), for example at the upper set level of the liquid level;
This is an overflow pipe for overflowing the absorption liquid that connects the high temperature generator (1) and the low temperature generator (2), and this overflow pipe is equipped with an orifice (25). (Sl)
is the first temperature measuring element provided in the overflow pipe (24), (
S2) is the second temperature measuring element provided on the side of the high temperature generator (liquid reservoir c!6 of 11), (0 is the temperature measuring element (Sl), (S2)
This is a controller that stops the operation of the solution pump (8) when the difference between the measured temperature values becomes less than a set value (for example, 5°C).

Figure 3 shows the thermometer (S+) (or thermometer (S2))
FIG. 4 is a schematic explanatory diagram showing two sides of the structure of the receiving part of the thermometer (S) placed in the overflow pipe (24). In Figures 3 and 4, (h) is the temperature sensing part of the temperature sensor (S,), (i) is a bolt with a male thread (2, 11 is an autocooled flow tube, (j ) is a container with a female thread formed on the top, and the bottom of this container is the overflow pipe 04)
inserted inside. (k+ is overflow pipe 1
This is the welded part between the container (i) and the container (i). Then, screw the male thread of the bolt (i) of the 3+11 warm body (S,) onto the female thread of the container (jl), and attach the temperature sensing part (hl of the temperature sensor (Sl) to the container (J).
By fitting the temperature sensing element (S,) into the overflow pipe C24). Although not shown in the figure, the temperature measuring element (S2) is similarly attached to the liquid reservoir (2G+ 1111) of the high temperature waste generator (1).

Next, an example of the operation of the absorption refrigerating machine controller R (hereinafter referred to as the present device) according to the present invention configured as described above will be briefly described.

During operation of the absorption chiller, if the liquid level in the high temperature generator ( ) is lower than the upper limit setting level, the overflow pipe (2
4) Since only refrigerant vapor flows inside the first temperature sensing element (
Sl) temperature measurement value (hereinafter referred to as the first if'jl temperature value)
indicates, for example, about 135°C. On the other hand, the second temperature measuring element (S) senses a temperature close to the temperature of the absorption liquid, so its temperature value (hereinafter referred to as the second temperature value) is approximately 155.
Indicates °C. Then, the first and second temperature measuring bodies (St), (S2
) The controller (0) detects that the difference between the second temperature measurement value and the first temperature measurement value is about 20 degrees Celsius, which is much larger than the set value (5 degrees Celsius), Based on this detection result, the solution pump (8) continues to operate.

In addition, during operation of the absorption chiller, if for some reason the liquid level in the high temperature generator (1) exceeds the upper limit setting level and a large amount of absorption liquid begins to flow in the overflow pipe, the The first temperature measuring element (S,) senses a temperature close to the temperature of the absorption liquid, so the first temperature measurement value is, for example, about 154°C.
shows. Then, the controller (0) detects that the difference between the second temperature measurement value and the first temperature measurement value is approximately 1°C, which is less than the set value (5°C), and based on this detection result, the solution pump Stop the operation of (8).

As a result, the flow of the absorption liquid into the high temperature generator (1) is blocked, and an excessive rise in the liquid level in the high temperature generator (1) is prevented. Although not shown, instead of controlling the start and stop of the solution pump (8), a valve is provided in the replacement fluid pipe 03), and by controlling the opening and closing of this valve, excessive rise in the filtrate level in the high temperature generator (1) can be prevented. It may be possible to prevent this.

In this way, in this device, it is possible to accurately detect that the liquid level in the high temperature generator (1) has reached the upper limit setting level, so that an excessive rise in the liquid level can be reliably prevented. In addition, in this device, the temperature measuring body (S, ), (S2)
Since the temperature is measured through the container (j) without bringing the temperature sensing part (b) of the body into contact with the absorption liquid, the temperature sensing part (h) of the temperature sensing body (Sυ, (S2)) may be corroded by the absorption liquid. Therefore, in this device, malfunctions do not occur as much as in conventional control devices using a city electrode type liquid level relay.

Furthermore, in this device, since the container (j) is attached by welding to the tube wall of the automatic flow tube (24) or the vessel wall of the high temperature generator (1), the possibility of vacuum leakage is also small.

Furthermore, since this device can use a generally commercially available temperature measuring body, it has the advantage of being easily applicable to explosion-proof specifications and other special specifications, and is inexpensive.

In addition, in this device, the temperature-sensing part (hl) of the temperature-measuring element is placed on the oat (-flow tube or reservoir) side by fitting it into the container (j). The temperature sensing part (h) of the body may be attached in close contact with the wall of the overflow pipe (24) or the wall of the high temperature generator (liquid reservoir (26+) side of 11).

Furthermore, in this device, the first thermometer (S, ) may be installed at any location on the T-bar 70-pipe (24), but It is preferable to install the absorbent liquid in the overflow tube (2) according to the experimental results. When the absorption liquid is flowing, the difference between the second temperature measurement value and the first temperature measurement value is 1 digit, whereas when the absorption liquid is not flowing, the difference is 2 digits.
Since the value is shown in digits, there is almost no possibility that this device will malfunction.

(f) Effects of the Invention As described above, the present invention provides a first temperature measuring element in the overflow pipe and a second temperature measuring element on the liquid reservoir side of the high temperature generator, and measures these temperature measuring elements. The difference in temperature values is detected, and based on this detection result, the supply of absorption liquid to the high temperature generator is started or stopped by controlling the start/stop of the solution pump or the opening/closing of the valve. Therefore, it is possible to reliably prevent an excessive rise in the liquid level within the high temperature generator.

In addition, in the control device according to the present invention, there is no need to bring the temperature-sensing part of the thermometer into contact with the absorbing liquid, so the sensor part does not corrode unlike the conventional control device using an electrode-type liquid level relay. It does not get dirty and has less chance of malfunction than conventional control devices.

[Brief explanation of drawings]

Fig. 1 is a schematic explanatory diagram showing the installation structure of an electrode type liquid level relay conventionally used in absorption refrigerators; Fig. 2 is a schematic explanatory diagram showing an embodiment of the device of the present invention; The figure is a schematic configuration explanatory diagram showing an example of a temperature measuring element used in the device of the present invention,
FIG. 4 is a schematic explanatory diagram showing an example of the structure of the mounting portion of the temperature measuring element in the overflow pipe. (1)...High temperature generator, (2)...Low temperature generator,
(8)...pump [solution pump], (24)...
Pipe [overflow pipe], 25+...orifice,
(26)...liquid reservoir, (0...controller, (Sl
), (82 units...temperature detector, (j)...container. Figure 1, Ward 3, Figure 4)

Claims (1)

[Claims] (1) A tube with a pressure regulator is connected between the high temperature generator and the low temperature generator so that the liquid level is above the upper limit setting level of the high temperature generator, and this tube is equipped with a temperature sensor and the high temperature A temperature measuring element is provided on the liquid reservoir side of the generator, and when the difference between the temperature values measured by the temperature measuring elements becomes less than a set value, the flow of absorption liquid to the high temperature generator is interrupted. Features of absorption chiller control device.