JP2000227263A - Control method of absorption chiller / heater - Google Patents

Abstract

(57) [Problem] Even if heating in a high-temperature regenerator is stopped when there is almost no heating load, the temperature of the hot water circulating to the heating load is heated by the Joule heat of the pump, resulting in an abnormally high temperature. The emergency stop of the equipment may occur, so prevent this. SOLUTION: At the time of heating operation of an absorption chiller / heater in which a high-temperature regenerator 1, a low-temperature regenerator 2, a condenser 3, an evaporator 4, an absorber 5, and the like are connected by piping to form a circulation path of an absorbent and a refrigerant. When the hot water outlet side temperature T1 detected by the temperature sensor 30 exceeds the set temperature, the refrigerant pump 19 is operated to transfer the low-temperature condensed refrigerant accumulated in the refrigerant reservoir of the evaporator 4 to the upper side of the heat transfer tube 21A. And the hot water flowing inside was cooled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption chiller / heater capable of selectively supplying cold water for performing a cooling action such as cooling and hot water for performing a heating action such as heating.

[0002]

2. Description of the Related Art In a heating operation using an absorption chiller / heater of this type, when the heating load is small, the amount of heat input to the high-temperature regenerator is suppressed to reduce the retained heat of the refrigerant vapor supplied from the high-temperature regenerator to the evaporator. When the heating load is large, the amount of heat input to the high-temperature regenerator is increased to increase the retained heat of the refrigerant vapor supplied from the high-temperature regenerator to the evaporator. The heating effect on the hot water passing through the inside of the heat pipe is reduced, and when the heating load is large, the heating effect on the hot water passing through the inside of the heat transfer tube is increased to cope with the increase and decrease of the load.

[0003]

However, in the above-described conventional absorption chiller / heater, even if the heating load in the high-temperature regenerator is stopped with little heating load, the piping is installed inside the evaporator. The hot water in the heat transfer pipe is heated by the Joule heat of the pump that circulates and supplies this hot water to the heating load. There was a problem, and this solution was a problem.

[0004]

According to the present invention, as a specific means for solving the above-mentioned problems in the prior art, a rare absorbing liquid having absorbed a large amount of refrigerant is heated to evaporate and separate the refrigerant, and the separated rare absorbing liquid is heated. A high-temperature regenerator for obtaining a refrigerant vapor and an intermediate absorbent; and an intermediate absorbent generated and supplied by the high-temperature regenerator, heated by the refrigerant vapor generated by the high-temperature regenerator to further evaporate and separate the refrigerant. A low-temperature regenerator that obtains a refrigerant vapor and a concentrated absorption liquid from a low-temperature regenerator, and supplies a refrigerant liquid that is heated and condensed by the intermediate absorption liquid, and cools the refrigerant vapor that is generated and supplied by the low-temperature regenerator And a refrigerant liquid supplied from the condenser and accumulated in the refrigerant liquid reservoir is sprayed on the heat transfer tubes by the refrigerant pump, and the refrigerant takes heat from the fluid flowing in the heat transfer tubes to generate refrigerant. An evaporator that evaporates, and The refrigerant vapor is separated from the low-temperature regenerator and is absorbed into the concentrated absorption liquid supplied to make the diluted absorption liquid, and the absorber supplied to the high-temperature regenerator is provided. The fluid can be supplied from the heat transfer tube of the evaporator to the portion to be cooled to perform a cooling operation, and the refrigerant vapor heated and generated by the high-temperature regenerator is connected to the evaporator so that the refrigerant vapor can be supplied to the evaporator. During the heating operation of the absorption chiller / heater, the fluid heated by the refrigerant vapor supplied from the evaporator can be circulated and supplied from the heat transfer tube of the evaporator to the heated portion to perform the heating operation. The refrigerant pump is activated when the temperature of the fluid exceeds a set temperature due to the Joule heat of the pump that circulates the fluid from the heat transfer tube of the evaporator to the heated portion from the heat transfer tube of the evaporator. Control method,

[0005] In the control method of the first configuration, when the temperature of the fluid does not fall below a set temperature even after operating the refrigerant pump for a predetermined time, the fluid is circulated from the heat transfer tube of the evaporator to the portion to be heated. And a second control method for stopping the operation of the pump.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. The example illustrated in FIG. 1 is a double-effect absorption chiller / heater that circulates cold or hot water to a load, and uses water as a refrigerant and lithium bromide (LiB
r) An aqueous solution is used.

In the figure, 1 is a high temperature regenerator equipped with a gas burner 1B, 2 is a low temperature regenerator, 3 is a condenser, 4 is an evaporator, 5 is an absorber, 6 is a low temperature heat exchanger, 7 is a high temperature heat exchanger. Vessel, 8-11 are absorption liquid pipes, 13 is absorption liquid pump, 14-
18 is a refrigerant pipe, 19 is a refrigerant pump, 21 is a cold / hot water pipe through which cold or hot water circulates to a cooling / heating load (not shown), 22 is a cold / hot water pump, 23 is a cooling water pipe, and 24 and 2
Reference numeral 5 denotes a pressure equalizing pipe, and 26 to 29 denote on-off valves. These devices are connected by pipes as shown in FIG. 1, and the configuration itself is conventionally known.

In the double-effect absorption chiller / heater of the above construction, the shut-off valves 26, 27, 28 and 29 are closed, cooling water is supplied to the cooling water pipe 23, and the gas burner 1B is ignited. When the absorbing liquid is heated, a refrigerant vapor evaporated and separated from the rare absorbing liquid and an intermediate absorbing liquid in which the refrigerant vapor is separated and the concentration of the absorbing liquid is increased are obtained.

The high-temperature refrigerant vapor generated by the high-temperature regenerator 1 enters the low-temperature regenerator 2 through the refrigerant pipe 14 and is generated by the high-temperature regenerator 1 and passes through the high-temperature heat exchanger 7 by the absorbing liquid pipe 9. Then, the intermediate absorbing liquid that has entered the low-temperature regenerator 2 is radiated and condensed by heating and enters the condenser 3.

The refrigerant heated in the low-temperature regenerator 2 and evaporated and separated from the intermediate absorbing liquid enters the condenser 3 and enters the cooling water pipe 2.
The refrigerant flows into the evaporator 4 through the refrigerant pipe 16 together with the refrigerant condensed and supplied from the refrigerant pipe 14 by exchanging heat with the water flowing in the inside 3.

The refrigerant liquid entering the evaporator 4 and stored in the refrigerant liquid reservoir is sprayed by a refrigerant pump 19 onto a heat transfer tube 21A connected to the cold / hot water pipe 21, and is supplied with water supplied through the cold / hot water pipe 21. The heat exchange evaporates and cools the water flowing inside the heat transfer tube 21A.

The refrigerant evaporated in the evaporator 4 enters the absorber 5 and is heated in the low-temperature regenerator 2 to evaporate and separate the refrigerant. It is supplied through the low-temperature heat exchanger 6 and is absorbed by the concentrated absorbent sprayed from above.

The absorption liquid whose concentration has been reduced by absorbing the refrigerant in the absorber 5, that is, the diluted absorption liquid, is regenerated at a high temperature via the low-temperature heat exchanger 6 and the high-temperature heat exchanger 7 by the operation of the absorption liquid pump 13. It is sent from the absorbing liquid tube 8 to the vessel 1.

When the absorption chiller / heater is operated as described above, the chilled water cooled by the heat of vaporization of the refrigerant in the heat transfer tube 21A provided inside the evaporator 4 is cooled by the operation of the chilled / heated water pump 22. Since it can be circulated and supplied to a cooling / heating load (not shown) through the water pipe 21, a cooling operation or the like can be performed.

On the other hand, the on-off valves 26, 27, 28 and 29 are opened, and the gas burner 1B
When the rare absorbent is heated by the high-temperature regenerator 1 and the refrigerant evaporated from the rare absorbent in the high-temperature regenerator 1, the refrigerant mainly passes through the refrigerant pipes 14 and 15 having a small flow path resistance and the absorber 5 and the evaporator. 4, heat exchange with the water supplied from the cold / hot water pipe 21 via the heat transfer tube 21A is condensed, and the water flowing inside the heat transfer tube 21A is heated mainly by the heat of condensation at this time.

The refrigerant condensed by performing the heating action in the evaporator 4 enters the absorber 5 through the refrigerant pipes 17 and 18, evaporates and separates the refrigerant in the high-temperature regenerator 1, and absorbs the refrigerant flowing from the absorption liquid pipe 11. It is mixed with the liquid and sent to the high-temperature regenerator 1 via the low-temperature heat exchanger 6 and the high-temperature heat exchanger 66 by the operation of the absorption liquid pump 13.

The hot water heated by the heat transfer pipe 21A inside the evaporator 4 is circulated and supplied to a cooling / heating load (not shown) through the cold / hot water pipe 21 by operating the cold / hot water pump 22, thereby performing a heating operation and the like. It is.

Note that even if the cooling water stagnating in the cooling water pipe 23 is heated by the absorber 5, the on-off valve 29 of the pressure equalizing pipe 25
Can be opened to release the pressure.
Pressure does not rise abnormally.

C is a controller provided in a double-effect absorption chiller / heater having the above-mentioned operation function, and is provided with a microcomputer, a storage means, etc., and supplies chilled / heated water to a cooling / heating load (not shown). The evaporator 4 is connected to the cold / hot water pipe 21 for circulating supply.
The temperature information of the cold / hot water flowing out of the heat transfer tube 21A is taken from the temperature sensor 30 provided at the outlet side of the evaporator 4 of the cold / hot water tube 21, and the temperature of the cold / hot water evaporator outlet side is maintained at a predetermined set temperature. Thus, by adjusting the opening of the heating amount control valve (not shown) connected to the gas burner 1B,
It has a conventionally well-known capacity control function for controlling the amount of heat input to the heat exchanger.

That is, the larger the difference between the predetermined set temperature and the temperature of the cold / hot water detected by the temperature sensor 30 is, the greater the degree of opening of the heating amount control valve connected to the gas burner 1B is set to the controller C. When the temperature of the cold / hot water detected by the temperature sensor 30 reaches the set temperature, the control program for performing the normal capacity control such as controlling the opening of the heating amount control valve to the set opening or closing the same is stored. It is stored in the means.

The controller C controls the operation of the absorbent pump 13 so that the liquid level of the absorbent in the high-temperature regenerator 1 is maintained at a predetermined level, and the temperature sensor 30 detects the temperature during cooling operation. The temperature of cold water is the set temperature (for example, 7 ° C)
A control program for operating the refrigerant pump 19 at a higher time is also provided in the storage means.

Further, the controller C circulates and supplies hot water heated to a set temperature (for example, 55 ° C.) by the heat transfer tube 21A of the evaporator 4 to a cooling / heating load (not shown) through the cold / hot water tube 21 for heating operation. When the control is performed, a control program for controlling the refrigerant pump 19 and the cold / hot water pump 22 as shown in FIG. 2 is also provided in the storage means.

That is, in step S1, the controller C detects the temperature T1 of the hot water heated by the heat transfer tube 21A installed in the evaporator 4 and flowing out of the cold / hot water tube 21 by the temperature sensor 30.

In step S2, the hot water outlet side temperature T1 detected by the temperature sensor 30 is set to, for example, 10 ° C.
It is determined whether the temperature is higher than the high 65 ° C. or not.

In step S3, the temperature T2 of the hot water returning from the cooling / heating load (not shown) through the cold / hot water pipe 21 to the heat transfer pipe 21A of the evaporator 4 is determined.
It is detected by a temperature sensor 31 installed on the entrance side.

In step S4, it is determined whether or not the temperature difference between the inlet and outlet of the hot water flowing through the cold / hot water pipe 21 to the evaporator 4 is smaller than 0.5 ° C. No, that is, the hot water is sufficient for the cooling / heating load. When returning with heat release, the process returns to step S1, and when yes, that is, when hot water returns with little heat release to the cooling / heating load, the process proceeds to step S5,
The refrigerant pump 19 is operated for a predetermined time, for example, 10 seconds.

After the operation of the refrigerant pump 19 is stopped, the process proceeds to step S6, where the hot water outlet side temperature T1 is detected by the temperature sensor 3.
Detect again with 0.

In step S7, the hot water outlet side temperature T1 is 6
It is determined whether the temperature is higher than 3 ° C., and if it is not higher, the process returns to step S1. If it is higher, the process proceeds to step S8, and the refrigerant pump 19 is operated again for 10 seconds. The temperature sensor 30
To detect further.

In step S10, the same determination as in step S7 is performed. If the hot water outlet side temperature T1 is not higher than 63 ° C., the process returns to step S1, and if it is higher than 63 ° C., the refrigerant pump 19 is operated to operate the low-temperature refrigerant. Even if the liquid is sprayed on the heat transfer tube 21A, the hot water outlet side temperature T1 does not drop to the predetermined set temperature. Therefore, the process proceeds to step S11, in which the operation of the cold / hot water pump 22 is stopped, and further proceeds to step S12, where the buzzer An alarm is issued by the sounding of lights, lighting or blinking of lights, and the control is terminated.

Therefore, according to the present invention, when the heating by the gas burner 1B is stopped to cope with a decrease in the heating load, the hot and cold water in the cold and hot water pipe 21 that is circulated and supplied to the heating load by the cold and hot water pump 22 becomes cold and hot. When the temperature is increased by the Joule heat of the water pump 22 and the temperature rises, the low-temperature condensed refrigerant liquid accumulated in the refrigerant liquid pool of the evaporator 4 is sprayed onto the heat transfer tube 21A by the refrigerant pump 19 which is operated each time, and the inside thereof is dispersed. , The temperature of the hot water flowing through the cold / hot water pipe 21 becomes abnormally high, the safety device operates, and the inconvenience of emergency stop of the equipment is almost eliminated.

The controller C includes a refrigerant pump 19
The operation for a predetermined time, the detection of the hot water outlet side temperature T1 by the temperature sensor 30, and the determination as to whether or not the hot water outlet side temperature T1 is higher than 63 ° C. may be repeated three or more times.

The controller C stops the operation of the refrigerant pump 19 once started when the hot water outlet side temperature T1 detected by the temperature sensor 30 is lower than a predetermined 63 ° C. at that time, and proceeds to step S1. Return, predetermined time, for example, 30
If the hot water outlet side temperature T1 does not become lower than 63 ° C. even after the continuous operation for two seconds, the control after step S5 may be configured so as to stop the operation of the refrigerant pump 19, issue an alarm, and end the control.

The controller C may be configured to omit the operations of steps S2 and S3 and control the operation of the refrigerant pump 19 and the cold / hot water pump 22.

[0034]

As described above, according to the present invention, when the heating of the absorbing liquid in the high-temperature regenerator is stopped to cope with a decrease in the heating load, the cold / hot water pump circulates and supplies the heating load. When the hot water is heated by the Joule heat of the cold / hot water pump and rises in temperature, the low-temperature refrigerant liquid accumulated in the refrigerant liquid pool of the evaporator is sprayed on the heat transfer tubes by the refrigerant pump that is operated each time, and the internal hot water is discharged. Since the temperature of the hot water circulating to the heating load becomes abnormally high, the safety device is activated, and the emergency stop of the equipment is almost eliminated, even if the cooling equipment is not separately installed.

When the temperature of the hot water does not decrease to the set temperature even when the refrigerant pump is operated, the operation of the cold / hot water pump is stopped to prevent the temperature of the hot water from rising further. There is no danger of damage.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an apparatus configuration.

FIG. 2 is an explanatory diagram of a control method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High temperature regenerator 1B Gas burner 2 Low temperature regenerator 3 Condenser 4 Evaporator 5 Absorber 6 Low temperature heat exchanger 7 High temperature heat exchanger 8-11 Absorbing liquid pipe 13 Absorbing liquid pump 14-18 Refrigerant pipe 19 Refrigerant pump 21 Cold / hot water pipe 22 Cooling / heating water pump 23 Cooling water pipe 24/25 Equalizing pipe 26-29 Open / close valve 30/31 Temperature sensor C Controller

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Sumio Ikeda 2-5-5 Keihanhondori, Moriguchi-shi, Osaka F-term in Sanyo Electric Co., Ltd. 3L093 AA05 BB11 BB22 BB29 BB31 BB37 DD10 EE17 GG02 HH08 HH19 JJ06 KK05 LL03

Claims (2)

[Claims] 1. A high-temperature regenerator that heats a rare absorbing liquid that has absorbed a large amount of a refrigerant to evaporate and separate the refrigerant, and obtains refrigerant vapor and an intermediate absorbing liquid from the rare absorbing liquid. A low-temperature regenerator that heats the intermediate absorption liquid to be produced with the refrigerant vapor generated by the high-temperature regenerator and further evaporates and separates the refrigerant to obtain a refrigerant vapor and a concentrated absorption liquid from the intermediate absorption liquid. Is supplied with the refrigerant liquid condensed by heating the refrigerant, and cools the refrigerant vapor generated and supplied by the low-temperature regenerator to obtain a refrigerant liquid; and a condenser supplied from the condenser and accumulated in the refrigerant liquid reservoir. The refrigerant liquid is sprayed onto the heat transfer tubes by the refrigerant pump, and the evaporator evaporates the refrigerant by removing heat from the fluid flowing in the heat transfer tubes, and the low-temperature regenerator Is separated from the refrigerant vapor and absorbed by the concentrated absorbent supplied. And an absorber for supplying a high-temperature regenerator to the diluted absorption liquid, and the refrigerant deprived of evaporation heat can be supplied from the heat transfer tube of the evaporator to the portion to be cooled to perform a cooling action. The refrigerant vapor heated by the high-temperature regenerator is connected to the evaporator via a pipe so that the refrigerant can be supplied to the evaporator, and the fluid heated by the refrigerant vapor supplied from the high-temperature regenerator is circulated from the heat transfer tube of the evaporator to the portion to be heated. During the heating operation of the absorption chiller-heater configured to be able to supply and perform the heating action, the load of the heated section is small, and the pump for circulating the fluid from the heat transfer tube of the evaporator to the heated section is supplied. A method for controlling an absorption chiller / heater, comprising activating a refrigerant pump when the temperature of the fluid exceeds a set temperature due to Joule heat. 2. When the temperature of the fluid does not fall below a set temperature even after operating the refrigerant pump for a predetermined time, the operation of the pump for circulating the fluid from the heat transfer tube of the evaporator to the portion to be heated is stopped. The method for controlling an absorption chiller / heater according to claim 1, wherein: