JP3143227B2 - Refrigerant freezing prevention device for absorption refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant freezing prevention device for an absorption refrigerator.

[0002]

2. Description of the Related Art As a refrigerant freezing prevention device of this type, for example, a cooling water pipe housed in an absorber and a condenser disclosed in Japanese Patent Application Laid-Open No. 58-221358 is connected to a cooling water pipe via a control valve. A cooling water bypass pipe that bypasses the absorber is provided, and a detector that detects a physical quantity such as a temperature of the refrigerant flowing through the evaporator is provided. The physical quantity reaches a first lower limit set value according to a signal from the detector. After that, the opening degree of the control valve is controlled to adjust the amount of cooling water to the absorber, and the physical quantity
A refrigerant freezing prevention device of an absorption refrigerator having a controller for stopping heating to a regenerator (described as a generator) and stopping circulation of an absorbing solution from a time when a lower limit set value is reached,

[0003] This refrigerant freezing prevention device is said to prevent the normal operation of the refrigerant due to the freezing of the refrigerant even when the temperature of the cooling water is remarkably lowered or when the flow rate of the refrigerant supplied to the evaporator in the initial operation is small. The problem was solved.

[0004]

However, Japanese Patent Application Laid-Open No.
In the refrigerant freezing prevention device proposed in Japanese Patent Application Laid-Open No. 8-221358, there is a problem that the cost is increased because the cooling water side pipe is piped through an expensive three-way valve.
The solution of this point has been an issue.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and comprises connecting a regenerator, a condenser, an evaporator, an absorber, and a heat exchanger with piping to form a refrigerant. In an absorption refrigerator that forms a circulation cycle of the absorption liquid, with means for detecting the refrigerant temperature of the evaporator,
When the refrigerant temperature detected by the means has dropped to the first predetermined temperature, the heating of the regenerator is stopped, the operation of the absorbent pump for sending the absorbing liquid from the absorber to the regenerator is stopped, and the inside of the absorber and the condenser is removed. Stop the water supply of the cooling water pipe provided via
And a controller that, when the refrigerant temperature rises to a second predetermined temperature higher than the first predetermined temperature, delays restarting the water supply to restart heating of a regenerator and restart operation of the absorbent pump. A refrigerant freezing prevention device for an absorption refrigerator,

An absorption refrigerator having a recycler, a condenser, an evaporator, an absorber, and a heat exchanger connected to each other to form a circulation cycle of a refrigerant and an absorbing liquid, has means for detecting a refrigerant temperature of the evaporator. When the refrigerant temperature detected by the means drops to a first predetermined temperature, the water supply to a cooling water pipe provided via the inside of the absorber and the condenser is stopped, and further,
When the refrigerant temperature drops to the second predetermined temperature, the heating of the regenerator is stopped, and the operation of the absorbent pump for sending the absorbing liquid from the absorber to the regenerator is stopped, and the refrigerant temperature is reduced to the first predetermined temperature. An absorption refrigerator having a controller that, when the temperature rises to a third predetermined temperature higher than the temperature, delays the restart of the water supply to the restart of the heating of the regenerator and the restart of the operation of the absorbent pump. By providing a refrigerant freezing prevention device, the problem of the related art is solved.

[0007]

In the refrigerant freezing prevention apparatus according to the first aspect, when it is confirmed by the temperature detection means that the temperature of the refrigerant in the evaporator has dropped to a first predetermined temperature, the heating in the regenerator and the temperature in the regenerator are reduced. Since the operation of the absorbent pump and the water supply of the cooling water pipe are stopped by the controller, the internal temperature of the absorber and the condenser increases,
Supply of refrigerant vapor to the condenser and absorption liquid (concentrated liquid) to the absorber
Supply is reduced.

For this reason, the effect of suppressing the evaporation of the refrigerant in the evaporator to prevent the temperature from lowering is greater than in the case where the water supply in the cooling water pipe is simply stopped, and the refrigerant temperature can be reduced within a short time. It does not rise and the refrigerant freezes.

When it is confirmed by the temperature detecting means that the refrigerant temperature in the evaporator has risen to the second predetermined temperature, the water supply is restarted by resuming the heating of the regenerator and the absorption liquid pump. Since the resumption of operation is performed with a delay of a predetermined time, cooling water is supplied after a sufficient amount of refrigerant vapor is supplied to the condenser, and no excessively cooled refrigerant liquid flows into the evaporator, and Since the vapor pressure of the absorber is also kept high until a sufficient amount of the refrigerant is sprayed in the evaporator, a rapid decrease in the temperature of the refrigerant is prevented.

In the refrigerant freezing prevention apparatus according to the second aspect, when it is confirmed by the temperature detecting means that the temperature of the refrigerant in the evaporator has decreased to a first predetermined temperature, water is supplied to the cooling water pipe. Is stopped by the controller, and further, when it is confirmed that the refrigerant temperature has dropped to the second predetermined temperature, the heating of the regenerator and the operation of the absorbent pump are stopped by the controller,

At the stage where the temperature has dropped to the first predetermined temperature, a gradual temperature reduction prevention measure is taken, and at the stage where the temperature has dropped to the second predetermined temperature, a reliable temperature reduction prevention measure described in the section of the apparatus according to claim 1. Therefore, gentle control is performed at the first stage, and freezing of the refrigerant is reliably prevented at the next stage.

When it is confirmed by the temperature detecting means that the refrigerant temperature in the evaporator has risen to a third predetermined temperature, the water supply is restarted in the same manner as in the apparatus according to the first aspect. Therefore, also in this case, the refrigerant liquid that has been cooled too much does not flow into the evaporator, and a rapid decrease in the temperature of the refrigerant is prevented.

[0013]

(Embodiment 1) A first embodiment will be described with reference to FIG. 1. Reference numeral 1 designates a combustion device 2 such as kerosene, which generates a refrigerant vapor by heating a dilute liquid to produce an intermediate liquid. A high-temperature regenerator for concentrating, 3 is a separator for separating the refrigerant vapor pumped from the regenerator and the intermediate liquid, and 4 is a low-temperature regenerator for heating the intermediate liquid to a concentrated liquid by the refrigerant vapor from the separator. 5, a condenser for cooling and condensing the refrigerant vapor from the regenerators 1, 4; 6, an evaporator for spraying / dropping the refrigerant liquid from the refrigerant distributor 24 to evaporate; Refrigerant vapor from the low-temperature regenerator 4
Absorber that absorbs the concentrated liquid from to maintain the inside of the vessel at low pressure,
Reference numeral 8 denotes a bubble pump for pumping the unevaporated refrigerant in the evaporator 6 by the heat of the refrigerant after heating the intermediate liquid in the low-temperature regenerator 4, and 9 and 10 low-temperature and high-temperature heat exchangers. Connected by a pipe 11, an intermediate liquid pipe 12, a concentrated liquid pipe 13, a diluted liquid pipe 15 having an absorbent pump 14, a refrigerant conduit 16, a refrigerant liquid pipe 17, and a refrigerant recirculation pipe 18 to form a circulation cycle of refrigerant and absorbent. are doing.

Reference numeral 19 denotes a cold water pipe routed through the interior of the evaporator 6, and reference numeral 20 denotes a cooling water pipeline routed through the interior of the absorber 7 and the condenser 5. Cooling water pump 21 is provided.

In the absorption refrigerator having the above structure, when the temperature of the cooling water flowing through the cooling water pipe 20 falls outside the design range, the concentrated liquid sprayed on the cooling water pipe 20 is excessively cooled, and the refrigerant absorption function becomes abnormal. Therefore, the surrounding refrigerant vapor is actively absorbed, and the refrigerant vapor pressure in the absorber 7 greatly decreases beyond the design range.

For this reason, in the adjacent evaporator 6 via the eliminator 22, the amount of evaporation of the refrigerant abnormally increases, a large amount of heat of vaporization is taken, and the temperature is greatly reduced. Fall into.

In order not to cause the above-mentioned inconvenience, the refrigerant freezing prevention device according to the present invention comprises a temperature detector 23 for detecting the temperature of the refrigerant flowing inside the refrigerant distributor 24,
And a controller 25 for outputting a required control signal based on the signal from the detector.

That is, when the refrigerant temperature detected by the temperature detector 23 drops to a first predetermined temperature (for example, 1 ° C.), the controller 25 stops heating the high-temperature regenerator 1, The operation of the absorption liquid pump 14 for sending the absorption liquid (dilute liquid) to the high-temperature regenerator 1 and the operation of the cooling water pump 21 are stopped, and the refrigerant temperature detected by the temperature detector 23 is equal to the first refrigerant temperature. When the temperature rises to a second predetermined temperature (for example, 4 ° C.) higher than the predetermined temperature, the heating of the high-temperature regenerator 1 and the operation of the absorbent pump 14 are first restarted, and thereafter a predetermined time (for example, 1 minute and 30 seconds) It is provided so that the operation of the cooling water pump 21 is restarted with a delay.

With the above configuration, when it is confirmed that the temperature of the refrigerant in the evaporator 6 has decreased to the first predetermined temperature, the heating of the high-temperature regenerator 1 and the operation of the absorbent pump 14 are performed. Since the controller 25 stops the supply of water through the cooling water line 20, the internal temperatures of the absorber 7 and the condenser 5 increase, and the amount of refrigerant vapor generated in the high-temperature regenerator 1 decreases. Of the absorption liquid (concentrated liquid) decreases.

Therefore, the supply of the refrigerant vapor from the high-temperature regenerator 1 to the condenser 5 is restricted, and the supply of the refrigerant liquid from the condenser 5 to the evaporator 6 is suppressed by suppressing the condensing action in the condenser. The evaporation of the refrigerant in the evaporator 6 is strongly suppressed by restricting the supply of the concentrated liquid to the device 7 and increasing the refrigerant vapor pressure in the absorber. For this reason, in the evaporator 6, the refrigerant temperature quickly rises, and the freezing of the refrigerant is more reliably prevented.

The evaporator 6 is detected by the temperature detector 23.
When it is confirmed that the refrigerant temperature has risen to a second predetermined temperature (for example, 4 ° C.) set in advance, the heating of the high-temperature regenerator 1 and the operation of the absorbent pump 14 are restarted, and a predetermined time (for example, (1 minute and 30 seconds), the operation of the cooling water pump 21 is restarted, so that the cooling water is supplied after a sufficient amount of refrigerant vapor is supplied to the condenser 5. For this reason, the refrigerant liquid that has been cooled too much does not flow into the evaporator 6, and the vapor pressure of the absorber 7 is also kept high until a sufficient amount of the refrigerant is sprayed in the evaporator 6, so that the refrigerant It is effectively prevented that the temperature suddenly drops and freezes.

(Embodiment 2) Embodiment 2 will be described with reference to FIG. 1, similarly to Embodiment 1. In this case, the controller 25 determines that the refrigerant temperature detected by the temperature detector 23 is equal to a first predetermined temperature (for example, , 2.5 ° C.), the operation of the cooling water pump 21 is stopped, and
When the refrigerant temperature decreases to a second predetermined temperature (for example, 1 ° C.), the heating of the high-temperature regenerator 1 is stopped, and the absorption liquid pump 1 is stopped.
4, and when the refrigerant temperature detected by the temperature detector 23 rises to a third predetermined temperature (for example, 4 ° C.) higher than the first predetermined temperature, heating of the high-temperature regenerator 1 The operation of the absorbent pump 14 is first restarted, and the operation of the cooling water pump 21 is restarted after a delay of a predetermined time (for example, 1 minute and 30 seconds).

Therefore, the first preventive measure against the temperature drop of the evaporator 6 is taken at the stage when the refrigerant temperature has dropped to the first predetermined temperature, and when the refrigerant temperature has dropped to the second predetermined temperature. In addition, since a second temperature drop prevention measure for stopping the heating of the high temperature regenerator 1 and the operation of the absorbent pump 14 is taken, the temperature drop of the refrigerant in the evaporator 6 is gradual and the water flowing through the cold water pipe 19 As a result, there is little fluctuation in the performance of cooling and the like, and freezing of the refrigerant is reliably prevented.

The temperature detector 23 detects that the refrigerant temperature in the evaporator 6 is a third predetermined temperature (for example, 4 ° C.).
The operation and effect after confirming that the temperature has risen to (.degree. C.) are the same as those in the first embodiment, and a description thereof will be omitted.

Since the present invention is not limited to the above-described embodiment, various modifications can be made without departing from the spirit of the appended claims.

For example, the temperature detector 23 is connected to the coolant reservoir 26.
May be installed in the refrigerator to detect the refrigerant temperature. The absorption refrigerator to be applied is not limited to the double-effect absorption refrigerator of the above configuration, and can be applied to a single-effect absorption refrigerator. Instead of 8, an ordinary pump or an absorption refrigerator having no separator 3 may be used.

[0027]

As described above, according to the refrigerant freezing prevention apparatus for an absorption refrigerator according to the present invention, the temperature of the cooling water is significantly reduced without using an expensive three-way valve, In the case where the amount of refrigerant supplied to the evaporator is small, the problem that the refrigerant is frozen in the evaporator and the operation becomes inoperable is solved by a refrigerant freezing prevention device proposed in JP-A-58-221358. Is possible,

In addition, compared to the conventional apparatus disclosed in Japanese Patent Application Laid-Open No. 58-221358, since the decrease in the refrigerant temperature when the operation is restarted is further reduced, the operation is less likely to be stopped again.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an apparatus according to the first and second aspects of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High temperature regenerator 2 Combustion apparatus 3 Separator 4 Low temperature regenerator 5 Condenser 6 Evaporator 7 Absorber 8 Bubble pump 9 Low temperature heat exchanger 10 High temperature heat exchanger 11 Pumping pipe 12 Intermediate liquid pipe 13 Concentrated liquid pipe 14 Absorption Liquid pump 15 Rare liquid pipe 16 Refrigerant conduit 17 Refrigerant liquid pipe 18 Refrigerant return pipe 19 Cold water pipe 20 Cooling water pipe line 21 Cooling water pump 22 Eliminator 23 Temperature detector 24 Refrigerant distributor 25 Controller 26 Refrigerant liquid reservoir

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masao Sudo 2-18-18 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Minoru Hasegawa 2--18 Keihanhondori, Moriguchi-shi, Osaka (56) References JP-A-3-207966 (JP, A) JP-A-58-221358 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 15/00 306

Claims (2)

(57) [Claims] 1. A means for detecting a refrigerant temperature of an evaporator in an absorption refrigerator in which a regenerator, a condenser, an evaporator, an absorber, and a heat exchanger are connected by piping to form a circulation cycle of a refrigerant and an absorbing liquid. And when the temperature of the refrigerant detected by the means is reduced to a first predetermined temperature, the heating of the regenerator is stopped, the operation of the absorbent pump for sending the absorbent from the absorber to the regenerator is stopped, and the absorber and the condenser are stopped. When the cooling water temperature is increased to a second predetermined temperature higher than the first predetermined temperature, the water supply is restarted. A refrigerant freezing prevention device for an absorption refrigerator, comprising: a controller that delays restart and restart of operation of the absorbent pump. 2. A means for detecting a refrigerant temperature of an evaporator in an absorption refrigerator in which a regenerator, a condenser, an evaporator, an absorber, and a heat exchanger are connected by piping to form a circulation cycle of a refrigerant and an absorbent. When the refrigerant temperature detected by the means drops to a first predetermined temperature, water supply to a cooling water pipe provided via the interior of the absorber and the condenser is stopped, and the refrigerant temperature further decreases to a second predetermined temperature. When the temperature has dropped to the predetermined temperature, the heating of the regenerator is stopped, and the operation of the absorbent pump for sending the absorbing liquid from the absorber to the regenerator is stopped, and the third predetermined temperature is higher than the first predetermined temperature. A refrigerant freezing prevention device for an absorption refrigerator, comprising: a controller that, when the temperature rises, restarts the water supply with a delay to restart heating of a regenerator and restart operation of the absorbent pump.