JPS60126560A - Double effect 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 double-effect absorption refrigerating machine (hereinafter referred to as a dual-effect absorption refrigerating machine), and particularly relates to a dual-effect absorption refrigerating machine equipped with a mechanism for measuring the amount of absorbed liquid in a high-temperature generator.

(b) In the prior art dual effect absorption refrigerator, the pressure inside the high temperature generator rises to about 710 imHg during full load operation. In addition, the pump that sends the absorption liquid from the absorber to the high-temperature generator (hereinafter referred to as the solution pump) has its head determined assuming full-load operation. When the pressure inside the high temperature generator drops to about 100 mmHg, the liquid level inside the high temperature generator rises excessively. As a result, a large amount of absorption liquid mixes into the refrigerant vapor generated in the high-temperature generator, reducing the refrigerating capacity, and the amount of liquid p′ in the absorber increases.
- decrease and cause the solution pump to cavitate.

Therefore, in a dual-effect absorption refrigerator, it is necessary to measure the liquid level in the high temperature generator and adjust the liquid level in the high temperature generator based on the measurement result.

Conventionally, in a dual-effect absorption refrigerator, an electrode-type liquid level relay is installed in the high temperature generator, and the liquid level is measured by this relay, as explained in Japanese Patent Publication No. 54-43216, for example. The amount of liquid in the high temperature generator is adjusted by Electrode-type liquid level relays measure the liquid level by using the difference in electrical resistance between when liquid is in contact with the electrode and when it is not, so the sensor of this liquid level relay The structure of the part is usually attached to the high temperature generator first.
The structure is as shown in the figure. In Figure 1, (
al is the sensor part of the electrode type liquid level relay, (bl is the sensor part (the wall of the absorption liquid tank with al), (d) is the electrode, (fl is the insulator for electrical insulation, (g) is the bolt, ( E) is a conductor of electricity.

This type of installation is structurally similar to the ``electrode (d)''.
There is a drawback that vacuum leaks easily occur from the gaps between f-(f) and the gaps between the bolts (g) and the wall (bl), which impedes the normal operation of the absorption chiller, and these gaps are wetted by the absorption liquid and refrigerant. This causes poor insulation, which causes the liquid level relay to malfunction.Furthermore, the surface of the electrode (d) corrodes or becomes dirty due to the influence of the absorbed liquid, making it difficult for the liquid level relay to malfunction.

(c) Object of the Invention The object of the present invention is to provide a dual-effect absorption refrigerator equipped with a measuring mechanism that can reliably detect the liquid level of a high-temperature generator without malfunction.

(B) Structure of the Invention The present invention provides a first structure in which a first
In addition, a second temperature measuring element is provided on the liquid reservoir side of the high temperature generator, and the liquid level is measured by detecting the difference between the temperature values of these temperature measuring elements.

With this configuration, when the absorption liquid is not overflowing into the overflow pipe, the temperature measurement value of the first temperature sensor shows a value close to the temperature of the refrigerant vapor, so the temperature of the absorption liquid in the high temperature generator increases. For example, the difference between the temperature measurement value of the second temperature measurement device and the temperature measurement value of the first temperature measurement device, which shows a value close to , is about 20℃, but for some reason the liquid level rises and overflows. When the absorbent liquid starts to flow into the pipe, the temperature value measured by the first temperature measuring element also comes to show a value close to the temperature of the absorbent liquid, so the difference in the measured temperature values is, for example, about 1°C, and there is almost no difference. Gana (naru)

Therefore, a rise in the liquid level within the high temperature generator can be reliably detected. Furthermore, according to the present invention, there is no need for the sensor part of the temperature measuring element to come into contact with the absorbing liquid or to be inserted into the overflow pipe, so there is no possibility of malfunctions like in conventional electrode type liquid level relays. is small and has high measurement reliability.

(E) Embodiment Figure 2 is a schematic diagram showing an embodiment of the dual-effect absorption refrigerator equipped with a measuring mechanism according to the present invention, in which (1,) is a high temperature generator, and (2) is a low temperature generator. generator, (3) is the condenser, (
4) is an evaporator, (5) is an absorber, (6) and (7) are solution heat exchangers, and (8) is a pump for absorbing liquid (solution pump).
, (91 is a refrigerant liquid pump, and these devices include refrigerant flow pipes (1, 0), 00), refrigerant liquid flow pipes (11), and refrigerant liquid return flow pipes (12+, (12)). ,
Replacement liquid flow tt 7:l The pipes (13) and (13) are connected from the inside to form a refrigerant and absorption liquid ρ circulation path. Note that the dilute liquid refers to an absorption liquid with a low absorbent concentration, the concentrated liquid refers to an absorption liquid with a high absorbent concentration, and the intermediate liquid refers to an absorption liquid with an absorbent concentration between that of the dilute liquid and the concentrated liquid.

06) is the heat supply for the high temperature generator (1), 07) is the heater for the low temperature generator (2), and (20) is the condenser (3), evaporator (4), and absorber, respectively. (5) is a heat exchanger provided in (2J) and (2J) are pipes through which heat source fluid flows, which are connected to the heat supply device (16); (22) and (2 are heat exchangers (
19), □□□, (to) are the pipes through which cold water or low-temperature heat source fluid flows; A tube through which fluid flows. Note that ■ is a valve provided in pipe 01).

and (2) the high temperature generator (1) is located at a position higher than the normal level of the liquid level in the high temperature generator (1) during normal operation, for example at the upper limit setting level of the liquid level. (1) and the low temperature generator (2) are connected to each other, and this overflow pipe is equipped with an orifice (251).The overflow pipe is equipped with a U-shaped pipe. (S+) is the first temperature measuring element provided in the overflow pipe (24);
2) is the second temperature measuring element provided on the liquid reservoir (26) side of the high temperature generator (1), (0 is the difference between the temperature values of these temperature measuring elements (Sl) and (S2) is the set value ( This is a controller that stops the operation of the solution pump (8) when the temperature drops below 5°C (for example, 5°C).This controller (C) is used to monitor the difference between the temperature values of the thermometers (Sl) and (S2). Detecting arithmetic unit (0 is built-in.

Figure 3 shows the thermometer (81) (or thermometer (82))
FIG. 4 is a schematic explanatory diagram showing an example of the structure of the mounting portion of the temperature sensing element (Sl) in the overflow pipe. In Figures 3 and 4, (h) is the temperature sensing part of the temperature sensor (S,), (i) is a bolt with a male thread, (24) & is an overflow pipe, (jl is This is a container with a female thread formed on the upper part, and the lower part of this container is inserted into the overflow pipe 04). (k) is the welded part between the overflow pipe (goods) and the container (jl).Then, the temperature measuring element (S, ) is screwed into the female thread of the container fjl to measure the temperature. By fitting the temperature sensing part (hl) of the body (Sl) into the container (j), the temperature sensing element (Sl) is inserted into the overflow pipe (2).
4). Although not shown, the temperature measuring element (S2) is similarly attached to the liquid reservoir (A) side of the high temperature generator (1).

Next, an operational example of a dual-effect absorption refrigerator equipped with a measuring mechanism having such a configuration (hereinafter referred to as the main mechanism) will be briefly described.

During operation of the absorption chiller, when the liquid level in the high temperature generator (1) is lower than the upper limit setting level, only refrigerant vapor flows in the overflow pipe, so the first temperature measuring element (S
l) temperature value (hereinafter referred to as the first temperature value) is, for example, approximately 1
Indicates 35°C. On the other hand, since the second temperature measuring body (S,) senses a temperature close to the temperature of the absorbing liquid, its temperature value (hereinafter referred to as second temperature value) indicates, for example, about 155°C. and,
A controller (q is a controller that receives temperature measurement signals from the first and second temperature measurement elements (Sl) and (S2), where the difference between the second temperature measurement value and the first temperature measurement value is approximately 20'C; It is detected that the temperature is much higher than the set value (5° C.), and the solution pump (8) continues to operate based on this detection result.

In addition, during operation of the absorption refrigerator, 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 (24), the first The temperature measuring element (Sl) will sense a temperature close to the temperature of the absorption liquid, so the first temperature value will be approximately 154, for example.
Indicates °C. Then, the controller (q) 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 (8)
stop the operation.

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, an excessive rise in the liquid level in the high temperature generator (1) is prevented. You can do it like this.

In this way, in this mechanism, it is possible to accurately detect that the liquid level in the high temperature generator (1) has reached the upper limit setting level, and therefore it is possible to reliably prevent the liquid level from rising excessively. In addition, in the main a root, the thermometer (S, ), (S2)
Since the temperature is measured through the container ('') without bringing the temperature sensing part (HL) into contact with the absorption liquid, the temperature sensing part (HL) of the temperature sensing element (Sl) and (S2) may be corroded by the absorption liquid. Therefore, an absorption refrigerator equipped with this mechanism does not malfunction as much as a conventional absorption refrigerator using an electrode type liquid level relay.

Further, in this mechanism, since the jl is attached by welding to the pipe wall of the container (overflow pipe t24) or the vessel wall of the high temperature generator (1), the possibility of vacuum leakage is small.

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

In addition, in this mechanism, the overflow pipe (24
) or the liquid reservoir (26) side, but the temperature sensing part (h) of the temperature sensor is installed on the pipe wall of the overflow pipe (24) or on the liquid reservoir 06) side of the high temperature generator (1). It may also be mounted in close contact with the wall.

Furthermore, in this mechanism, the first temperature sensing element (St) may be placed anywhere in the overflow pipe, but it can be placed anywhere on the wall of the high temperature generator (1) or in the overflow pipe Q4). It is preferable to install it at a location where the temperature measurement error due to the influence of heat conduction of the tube wall is small. However, according to the experimental results, when the absorption liquid flows into the overflow pipe r2a, the difference between the second temperature measurement value and the first temperature measurement value shows a one-digit value, whereas the absorption liquid When there is no flow, the difference shows a two-digit value, so there is almost no possibility that this mechanism will malfunction ('.

Although not shown, a large number of overflow tubes may be sequentially provided above and each of these overflow tubes may be provided with a temperature measuring element to measure the vertical movement of the liquid level. Then, based on this measurement result, the discharge amount of the solution pump or the opening degree of the valve provided in the replacement fluid pipe may be adjusted.

(F) Effects of the Invention As described above, the present invention provides a temperature measurement value of the temperature measurement element provided in the overflow pipe of the high temperature generator and a temperature measurement value of the temperature measurement element provided on the liquid reservoir side of the high temperature generator. Since it is designed to detect the variation in the difference in the temperature, it has the effect of being able to reliably grasp the change in the liquid level in the high temperature generator (I'1).

In addition, in the measurement mechanism according to the present invention, there is no need for the temperature-sensing part of the thermometer to come into contact with the absorbing liquid, so unlike an electrode-type liquid level relay, the sensor part does not corrode or become dirty due to the influence of the absorbing liquid. Compared to electrode-type liquid level relays, there are fewer malfunctions and higher measurement reliability.

[Brief explanation of drawings]

Fig. 1 is a schematic explanatory diagram showing the structure in which the sensor part of a conventional electrode type liquid level relay is attached to the wall of an absorption liquid tank, and Fig. 2 is an example of a Nikoki effect absorption refrigerator equipped with the measuring mechanism of the present invention. FIG. 3 is a schematic configuration diagram of the temperature measuring element, and FIG. 4 is a schematic diagram showing the structure of attaching the container to the overflow pipe. (1)...High temperature generator, (2)...Low temperature generator,
(24)...Overflow pipe, Infusion...Liquid reservoir, (O...Arithmetic unit, (S,), (S,)...Temperature sensing element, (hl...Temperature sensing part, ( j)...Container.

Claims (1)

[Claims] (1) A temperature sensing element installed in the overflow pipe that causes the absorption liquid to overflow from the high temperature generator to the low temperature generator, a temperature sensing element installed on the liquid reservoir side of the high temperature generator, and a temperature sensing element installed in the overflow pipe with this temperature sensing element. A dual-effect absorption refrigerating machine characterized by being equipped with a liquid level measuring mechanism comprising a calculation unit that determines the liquid level in a high temperature generator by detecting a difference in temperature value from a temperature measuring element.