JPS59119160A - Method of preventing crystallization of 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 a method for preventing crystallization of a solution in an absorption refrigerator. In this specification, "
The term "absorption refrigerator" also includes a narrowly defined heat pump that pumps heat from a subtemperature section and supplies it to a high temperature section.

In an absorption heat pump, for example, if there is a large change in cooling water temperature or if there is a large change in condensation temperature, there is a risk that the solution will crystallize.

To take an example where the temperature of the cooling water changes significantly, when used as a beat pump in the narrow sense, the temperature of the cooling water at startup is significantly different from the temperature of the cooling water during steady operation. For this reason, even if the same heat source temperature, for example the same steam temperature, is used, the amount of heat transfer in the generator varies greatly, and a large amount of refrigerant is released from the generator at startup, resulting in a very concentrated solution. There is a danger of crystals.

For example, in the example shown in Figure 1, the condensation temperature is 80°C1
In a B r -)-120 type absorption heat pump designed to have a generator outlet solution temperature of about 140° C., a cycle like A occurs in steady operation, and the generator outlet solution is balanced at a concentration of 63%. Even after startup, the chilled water temperature remains low for a while (especially when a heat storage tank is used or when there is a large amount of cooled water, i.e. hot water, it takes a long time), and the condensing temperature only rises to about 40℃. If not, and with the same heat source and constant vapor pressure, if the generator outlet temperature exceeds 120°C, the cycle will be as shown in B, and the solution concentration will exceed 70% at the generator outlet. It reaches about 73% and reaches crystal line K before returning to the absorber and crystallizes. In this case, the average concentrations in cycle 8 and cycle B are almost the same, and the conventional method of trying to prevent crystallization by estimating the average solution concentration from the evaporator refrigerant liquid level is not effective in preventing crystallization. It is not prevention.

To give an unusual example of a change in condensing temperature, if the cooling water system is dirty and a large amount of scale is expected to arrive, the refrigerator should be turned on so that it can reach the specified capacity with the scale still on. Designed. In such cases, the condensing temperature changes significantly before and after scale adhesion, and when installing a new facility or immediately after removing scale, the condensing temperature may be higher than the refrigerant being discharged, causing a large amount of solvate to be generated.
The concentration becomes too high, leading to the danger of crystal formation.

Also, if the temperature of the heating source for the generator changes drastically,
During intense heating, a large amount of refrigerant is generated, which increases the concentration of the solution and poses a danger of crystal formation.

The present invention eliminates the above-mentioned drawbacks of the conventional method and solves the problem of
The object of the present invention is to provide a method for preventing crystallization in an absorption refrigerator by preventing overload from being applied to the solution at the time of installation and eliminating the risk of crystallization.

The present invention provides a method for preventing crystallization of an absorption refrigerator having an absorber, a generator, a condenser, an evaporator, and a solution path and a refrigerant path connecting these devices. An absorption refrigerating machine characterized in that, when the detected value exceeds a set value, both refrigerant liquids containing vapor are mixed into the generator or into the volume of liquid flowing into and out of the generator. This is a method of preventing crystallization.

An embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 2, an absorber A, a generator G, a condenser C1, an evaporator E, a solution heat exchanger '<
1.2.3.4.5 Piping is provided as a solution route.
, a spray pipe 6, and an overflow pipe 7, and piping 8.9, spray pipe 10, and piping 11 as refrigerant paths connect the above-mentioned devices to form a refrigeration cycle.

12 is a heating tube, ] 3 is a heat source calorie adjustment valve.

The cooling water system includes a cooling water pump 14, piping 15, cooling water pipe 16, piping 17, cooling water pipe 18, and piping 19, and is configured to cool the absorber A and the condenser C. There is also a method of cooling with air instead of cooling water. In this case, a cooling fan is used instead of the cooling water pump 14. 20
is a cold water pipe which leads cold water to the evaporator E through pipes 21 and 22.

23 is a liquid level gauge that detects the height of the refrigerant liquid level in the condenser C;
24 is a bypass pipe connecting the pipe 11 and the generator;
5 is a control valve, 26 is a controller, and 27 is an orifice.

Is the control valve 25 normally closed, or is the temperature inside the condenser C detected by the liquid level gauge 23? When the liquid level of the pseudo-condensed refrigerant exceeds a set value, the signal activates the controller 26, opens the control valve 25, and mixes a portion of the refrigerant into the solution in the generator G. ing. The tip of this bypass pipe 24 is connected not only to the generator G, but also to pipes 3.4.5, solution heat exchanger
You can also connect to Alternatively, it may be connected to absorber A. There is no problem even if the refrigerant liquid is accompanied by refrigerant vapor when mixed into the solution.

To explain the operation, when the discharge of refrigerant in the generator G increases due to the various causes mentioned above, the amount of condensation in the condenser C also increases and the flow rate of the condensed refrigerant liquid increases. Along with this, the liquid level in the condenser C also rises. When the height of the liquid level exceeds a set value, a signal from the liquid level gauge 23 activates the controller 26 to open the control valve 25. A portion of the refrigerant liquid flows into generator G via bypass pipe 24 to dilute the solution, lowering its concentration and preventing crystallization. When the liquid level drops due to the branching of the refrigerant liquid to the bypass pipe 24, the control valve 25 is closed again.

In the second embodiment, the flow rate of the condensed refrigerant liquid is detected by detecting the refrigerant liquid level in the condenser C, and the concentration of the solution is estimated from this to prevent the concentration from becoming high. In Although,? Detection of the flow rate of the vertical line refrigerant liquid may be performed by the pond method. Examples will be described below.

For example, as shown in FIG.
4, the refrigerant liquid may be made to flow down into the refrigerant receiver 30 via the orifice 29 connected to the generator G. In this case, the differential pressure across the orifice 29 is detected as a liquid level, and the space before and after the orifice 29 is communicated with the interior of the refrigerant receiver 30 to maintain the same pressure. As in the previous example, the liquid level height is detected by the liquid level gauge 23, and if it exceeds a set value, the control valve 25 is opened and the refrigerant is mixed into the solution in the generator G.

FIG. 4 shows an example of starvation, in which a refrigerant chamber 31 is provided in the flow path of the refrigerant liquid going from the condenser C to the pipe 11.
will be established. Instead of providing the orifice 27, the orifice action of the pipe 11 itself may be used. When the liquid level in the refrigerant chamber 31 exceeds a set value, the refrigerant liquid flows over the weir 32 and mixes into the solution in the generator G.

FIG. 5 shows an embodiment of a pond, in which the height of the inlet of the bypass pipe 24 of the refrigerant reservoir 28 having an orifice 29 is increased to form a weir 32 in a part of the wall.
When the liquid level of 8 exceeds the set value, the refrigerant liquid overflows over the basin 32 and flows into the generator G.

The condensed refrigerant liquid flow rate (i.e., the amount of generated refrigerant vapor) is calculated as “heat of condensation/
It can also be calculated based on the "latent heat of condensation". The amount of heat of condensation can be detected by the amount of heat transferred in the condenser C, that is, the amount of heat received by the cooling water, and the temperature of the cooling water.

Therefore, the cooling water temperature difference and the cooling water flow rate at the inlet and outlet of the condenser C are detected, and the condensed refrigerant liquid flow rate is calculated based on the detected values. If the set value is exceeded, the refrigerant liquid is transferred to the generator G. etc. will be introduced.

In addition, since the amount of refrigerant vapor generated corresponds to the amount of heating in the generator (electrical generator), the flow rate of the condensed refrigerant liquid can also be determined by detecting the amount of heating. For example, in the case of steam drive,
It can be determined by detecting the amount of condensed steam or the steam flow rate.

The following is an example of a single-effect absorption refrigerator, or it can be similarly applied to a double-effect absorption refrigerator. That is, the above method is applied between the condenser and the one-condensation generator, and when there is a large amount of refrigerant liquid from the condenser, the excess refrigerant liquid is added to the solution in the low temperature generator.

In addition, if the heating side of the low temperature generator is regarded as a condenser and the above method is applied between it and the high temperature generator, if the amount of refrigerant generated in the high temperature generator and condensed in the low temperature generator is large, this refrigerant liquid () into the solution of the high temperature generator.

In the above examples, the refrigerant liquid introduced into the solution is a condensed dC
It may be led from the evaporator E other than from the 1 pipe 11 or the like.

According to the present invention, it is possible to provide a method for preventing crystallization of an absorption refrigerator, which can prevent a solution from being overconcentrated and eliminate the risk of crystallization even when starting up or newly installed.
In practical terms, it has the same effect as a dog.

[Brief explanation of the drawing]

Fig. 1 is a cycle diagram of an absorption refrigerator, Fig. 2 is a 70-diagram of an embodiment of the present invention, and Figs. 3, 4, and 5 are embodiments of several refrigerant liquid flow rate measurement structures of the present invention. FIG. A...Absorber, G...Generator, C...Condenser, E...Evaporator, X...Solution heat exchanger, Sl)...Solution pump, R
P... Refrigerant pump, 1.2.3.4.5... Distribution % I, 6
...Spray pipe, 7..Overflow pipe, 8.9...
Delivery! ', 10...Spray pipe, 11...Piping, 12...
Heating pipe, 13...Heat source heat amount control valve, 14...Cooling water pump, 15...Piping, 16...Cooling water pipe, 17...Piping,
18... Cooling water pipe, 19... Piping, 20... Cold water pipe, 2
], 22... Piping, 23... Level gauge, 24... Bypass pipe, 25... Control valve, 26... Controller, 27... Orifice, 28... Refrigerant liquid reservoir, 29... Orifice, 30
... Refrigerant receiver, 31.. Refrigerant chamber, 32.. Cough. Patent applicant Minoru Sen 1) Patent attorney representing Ebara Corporation

Claims (1)

[Claims] 1. A method for preventing crystallization of an absorption refrigerator having an absorber, a generator, a condenser, an evaporator, and a solution path and a refrigerant path connecting these devices; Detects the refrigerant liquid flow rate and when the detected value exceeds the set value,
A method for preventing crystallization in an absorption refrigerator, characterized in that a refrigerant liquid, which may contain vapor, is mixed into the generator or into the δ liquid flowing into and out of the generator. 2. The flow rate of the condensed refrigerant liquid is detected by detecting the liquid level of the refrigerant liquid in the condenser or a chamber communicating with the condenser.
The method described in section. 3. The method according to claim 1, which is carried out by detecting the flow rate of the condensed refrigerant liquid or by detecting the amount of heat required for heating in the generator. 4. The method according to claim 1, wherein the flow rate of the condensed refrigerant liquid is detected by detecting the flow rate of cooling water in the condenser and the temperature difference between the inlet and outlet of the cooling water. 5. Detection of the flow rate of the condensed refrigerant liquid or a weir provided in the refrigerant liquid flow path, and if the flow rate exceeds a set value, the refrigerant liquid crosses the outside of the above-mentioned wall and enters and exits the generator or the generator. The method according to claim 11, wherein the method is mixed into a solution of