KR101012051B1 - Absorption heat pump - Google Patents

Abstract

An object of this invention is to provide the absorption type heat pump which prevented the crystallization of the concentrated absorption liquid resulting from the partial load during heating operation.

In order to solve the said subject, while installing the heat-source water pump 18 in the upstream of the heat exchanger tube 17 which passes through the inside of the evaporator 4, the flow rate detection means 19 is installed in the downstream, and further the evaporator ( At the bottom of 4), the coolant liquid temperature sensor 20 is installed. When the flow rate of the heat source water decreases below the set value or when the heat source water pump 18 stops, the crystallization of the concentrated absorbent liquid is prevented by performing the dilution operation of the absorbent liquid without immediately stopping the operation. When the heat source water may be frozen, the temperature of the refrigerant liquid stored at the bottom of the evaporator 4 is measured by the refrigerant liquid temperature sensor 20, and the temperature of the refrigerant liquid exceeds a predetermined temperature. The dilution operation of the absorbent liquid is carried out. When the temperature is lower than the predetermined temperature, the operation stops.

Absorption heat pump, evaporator, heat source water pump, refrigerant liquid temperature sensor

Description

Absorption Heat Pump {ABSORPTION HEAT PUMP}

The present invention relates to an absorption type heat pump which prevents crystallization of the absorbent liquid and prevents freezing of the heat source water during heating operation.

Conventionally, for example, an absorption heat pump using water as a refrigerant and a lithium bromide (LiBr) solution as an absorption liquid is known. This absorption type heat pump is a main component, a regenerator for heating a rare absorbent liquid returned from the absorber to separate refrigerant vapor, a condenser for condensing and liquefying refrigerant vapor transferred from the regenerator, and a refrigerant liquid transferred from the condenser. And an absorber which absorbs the refrigerant vapor transferred from the evaporator by spraying the concentrated absorbent liquid transferred from the regenerator from the spreader (e.g., For example, patent document 1).

When the single-use absorption heat pump as described above is used for heating operation, the heat source water is passed as a sub-heat source to the heat transfer tube passing through the evaporator, and the refrigerant liquid transferred from the condenser to stay at the bottom of the evaporator The refrigerant pump is sent to a sparger installed in the upper part of the evaporator and sprayed to the heat transfer tube. When the refrigerant liquid evaporates, heat is removed from the heat source water flowing through the heat transfer tube, and the refrigerant vapor is sprayed into the concentrated absorbent liquid sprayed in the absorber. When absorbed, warm water (cold water returned from the load) flowing in the hot water pipe passing through the absorber is warmed. The hot water heated by the absorber is heat-exchanged with the refrigerant vapor transferred from the regenerator when the hot water pipe passes through the condenser, is further warmed, and then supplied to the load to be used as a heat source for heating.

In this case, a flow rate detection means is provided in the outlet side heat exchanger tube of the evaporator, and the flow rate detection means monitors the flow rate of the heat source water. When the flow rate of the heat source water decreases and becomes equal to or lower than the set value, a signal is inputted from the flow rate detection means to the control device, and a signal is output from the control device to the hot water pump provided in the inlet heat transfer pipe of the absorber, thereby providing the hot water. The pump stops and the heating operation is stopped immediately.

However, if the heating operation is stopped immediately, the absorbent liquid pump for returning the rare absorbent liquid stored in the absorber to the regenerator stops, so that the absorbent liquid does not flow in the circulation path connecting the regenerator and the absorber, so that the absorber liquid does not flow in the pipeline from the regenerator to the absorber and on the way. The concentrated absorbent liquid remains in the heat exchanger. If the stop time is prolonged in such a state, the concentrated absorbent liquid may be cooled and crystallization may occur.

If crystallization of such concentrated absorbent liquid occurs, the flow of concentrated absorbent liquid is inhibited at the time of resuming operation thereafter, and normal operation immediately becomes impossible. For this reason, prior to resuming operation, the pipe leading from the regenerator to the absorber must be heated with a heater or the like to dissolve the crystals, and the cumbersome work is forced. In particular, in the case of crystallization in a heat exchanger provided at a position halfway between the regenerator and the absorber, the melting operation by heating becomes very difficult.

[Patent Document 1] Japanese Unexamined Patent Publication No. 8-233391

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the conventional absorption heat pump, and provides an absorption heat pump that prevents the crystallization of the concentrated absorbent liquid when the flow rate of the heat source water is decreased during the heating operation. The purpose.

As a means for achieving the above object, the first aspect of the present invention is a regenerator for separating the refrigerant vapor by heating the rare absorption liquid returned from the absorber; A condenser to condense and liquefy the refrigerant vapor conveyed from the regenerator; An evaporator for evaporating the refrigerant liquid conveyed from the condenser; And the absorber for absorbing the refrigerant vapor transferred from the evaporator, and installed in the heat transfer tube upstream of the evaporator when the flow rate of the heat source water flowing in the heat transfer tube passing through the evaporator decreases below a set value during heating operation. When the one heat source water pump stops, the absorption type heat pump is characterized in that the dilution operation of the absorbent liquid is performed without immediately stopping the operation.

According to a second aspect of the present invention, in the absorption heat pump of the first aspect, a flow rate detecting means is provided in a heat transfer tube downstream from the evaporator, and the flow rate of the heat source water flowing through the heat transfer tube is adjusted through the flow rate detection means. At the same time, the detection signal is input to the control device when the flow rate of the heat source water decreases below the set value.

According to the third aspect of the present invention, in the absorption heat pump of the first aspect, when the heat source water may be frozen, the temperature of the refrigerant liquid stored in the bottom of the evaporator is measured, and the The dilution operation of the absorbent liquid is performed when the temperature exceeds the predetermined temperature, and the operation is stopped when the temperature is lower than the predetermined temperature.

In the fourth aspect of the present invention, in the absorption type heat pump of the third aspect, a temperature sensor is provided at the bottom of the evaporator, and the temperature sensor detects the temperature of the refrigerant liquid stored at the bottom of the evaporator. At the same time, the detection signal is input to the control device.

According to the invention of the first aspect, the operation of the absorption type heat pump is performed immediately when the flow rate of the heat source water drops below the set value or when the heat source water pump installed in the heat transfer pipe upstream of the evaporator is stopped. Since the dilution operation of the absorbent liquid is performed without stopping, the concentrated absorbent liquid is not left in the conduit from the regenerator to the absorber. For this reason, crystallization of the concentrated absorbent liquid can be suppressed, and the flow of the concentrated absorbent liquid is not impaired at the time of resuming operation, and normal operation can be performed immediately. In addition, prior to the resumption of operation, the conventional cumbersome operation of warming the pipeline to dissolve the crystals in the concentrated absorbent liquid is not required.

According to the invention of the second aspect, when the flow rate of the heat source water decreases below the set value by providing the flow rate detecting means in the heat transfer tube downstream from the evaporator, the detection signal is inputted to the control device to ensure the control device. The dilution operation signal can be output.

According to the invention of the third aspect, when the heat source water may be frozen, the temperature of the refrigerant liquid stored at the bottom of the evaporator is measured, and when the temperature of the refrigerant liquid exceeds a predetermined temperature, the absorbing liquid. By performing the dilution operation of, the crystallization of the concentrated absorbent liquid can be prevented. In addition, when the temperature of the coolant liquid reaches a predetermined temperature or less, freezing of the heat source water in the heat transfer tube in the evaporator can be suppressed to the maximum by stopping operation.

According to the invention of the fourth aspect, by installing a temperature sensor at the bottom of the evaporator, by detecting the temperature of the coolant liquid stored at the bottom of the evaporator, the heat source water can be monitored so as not to freeze. . In addition, by inputting a detection signal by the temperature sensor to the control device, when the temperature of the coolant liquid becomes below a predetermined temperature, an operation stop signal can be output.

Hereinafter, an embodiment of the absorption type heat pump according to the present invention will be described with reference to the accompanying drawings.

1 is a block diagram showing the main part of the absorption type heat pump according to the present invention. In this figure, 1 is a regenerator, 2 is a condenser, and these are accommodated in the upper body (namely, the upper body) 3, and the lower part is partitioned by the partition plate 3a. (4) is an evaporator, (5) is an absorber, These are accommodated in the lower fuselage 6, and the partition is partitioned by the partition plate 6a in the lower part.

Reference numeral 7 denotes a drive heat source tube through which a drive heat source (main heat source) flows, which is piped to pass through the regenerator 1, and a flow rate control valve 8 is provided upstream from the regenerator 1. As the driving heat source, steam or hot water or the like can be used, for example, supplied from a supply source such as a boiler or an engine.

In the regenerator 1, a low concentration absorbent liquid (hereinafter referred to as " absorbent liquid ") supplied from the absorber 5 via the absorbent liquid pump 9 and the rare absorbent liquid tube 10 is referred to as the drive heat source tube 7 The refrigerant vapor is separated by heating by a driving heat source passing through the chamber.

The refrigerant vapor separated from the rare water absorbing liquid by the regenerator 1 flows into the adjacent condenser 2 and is cooled to become a refrigerant liquid and is stored in the bottom of the condenser 2. In this condenser 2, it is piped so that the hot water pipe 11 may pass, and this hot water pipe 11 passes through the inside of the condenser 2 after passing through the said absorber 5. In addition, a hot water pump 12 is provided upstream of the absorber 5 in the hot water pipe 11, and a hot water outlet temperature sensor 13 is provided downstream of the condenser 2. Based on the temperature detection by this hot water outlet temperature sensor 13, the opening / closing valve of the said flow control valve 8 is controlled, and the drive heat source supplied to the regenerator 1 is adjusted.

The coolant liquid stored at the bottom of the condenser 2 flows down into the evaporator 4 by the coolant liquid supply pipe 14, is supplied to the bottom of the evaporator 4, and at the same time, the coolant liquid pump ( 15 is supplied to the spreader 4a provided in the upper part of the evaporator 4 via the refrigerant | coolant liquid pipe 16, and it spreads | spreads. In this evaporator 4, the heat-transfer tube 17 through which heat source water (sub-heat source) flows passes, and the heat source water pump 18 is provided upstream than the evaporator 4 in this heat-transfer tube 17, On the downstream side of the evaporator 4, the flow rate detecting means 19 is provided. As this flow rate detection means 19, a flow switch can be used, for example. In addition, a coolant liquid temperature sensor 20 is provided outside the bottom of the evaporator 4.

The absorbent liquid (hereinafter, the concentrated absorbent liquid) in which the concentration of the refrigerant is separated by the regenerator 1 (hereinafter, the concentrated absorbent liquid) flows down to the absorber 5 by the absorbent liquid supply pipe 21 and is supplied to the upper part of the absorber 5. It is sprayed from the spreader 5a. The heat exchanger 22 is provided in the middle of this absorbent liquid supply pipe 21, and the said concentrated absorbent liquid 10 passes through the inside of this heat exchanger 22, and the hot concentrated absorbent liquid and low temperature rare absorbent liquid heat-exchange.

Reference numeral 23 is a control device, which is connected to the flow rate detecting means 19 and the coolant liquid temperature sensor 20, and at the same time, the heat source water pump 18, the coolant liquid pump 15, the absorbent liquid pump 9, and hot water. It is connected with the pump 12 and the flow control valve 8. The flow rate control valve 8 is connected to the hot water temperature sensor 13.

The absorption heat pump according to the present invention configured as described above can be heated by supplying a drive heat source to the drive heat source tube 7 and by supplying a sub-heat source to the heat transfer tube 17. As the sub-heat source, for example, heat source water pumped up from the basement can be used.

In the heating operation, for example, water vapor is supplied to the drive heat source tube 7 to heat the rare water absorbing liquid in the regenerator 1 to separate the refrigerant vapor. The refrigerant vapor separated from the regenerator (1) flows into the condenser (2), radiates and condenses the hot water flowing through the hot water pipe (11) in the condenser (2), and becomes a refrigerant liquid to form the bottom of the condenser (2). Is stored in.

The coolant liquid stored at the bottom of the condenser 2 is supplied to the evaporator 4 by the coolant liquid supply pipe 14 and is spreader 4a via the coolant liquid pipe 16 by the coolant liquid pump 15. ) Is sprayed toward the heat transfer pipe 17. This sprinkled refrigerant liquid takes heat from the heat source water flowing through the heat transfer pipe 17 in the evaporator 4, evaporates it, becomes a refrigerant vapor, and flows into the absorber 5.

The refrigerant vapor flowing into the absorber 5 is supplied from the regenerator 1 to the absorber 5 by the absorbent liquid supply pipe 21, and is absorbed by the concentrated absorbent liquid sprayed from the spreader 5a to form a rare absorbent liquid. It is stored at the bottom of the absorber 5. Then, the rare absorbent liquid stored in the lower part of the absorber 5 passes through the rare absorbent liquid pipe 10 by the absorbent liquid pump 9, and is heated in the heat exchanger 22 before being supplied to the regenerator 1. do.

In this way, the refrigerant and the absorbing liquid are circulated respectively, and the hot water passing through the hot water pipe 11 is heated by heat exchange with the refrigerant vapor when passing through the absorber 5, and then, when passing through the condenser 2, the refrigerant vapor. Heats and is re-heated, supplied to a load not shown, and used as a heat source for heating. The hot water whose heat is dissipated by the load and the temperature decreases is returned to the inlet side of the hot water pipe 11 via a pipe line (not shown), and is supplied to the hot water pipe 11 by the hot water pump 12.

When the flow rate of the heat source water supplied to the heat transfer pipe 17 decreases, and the flow rate detection means 19 of the heat source water detects the flow rate below the set value or the heat source water pump 18 stops, the operation is immediately performed. The dilution operation is performed without stopping.

This dilution operation closes the flow control valve 8 to stop the supply of water vapor to the regenerator 1, and operates the absorbent liquid pump 9 to return the rare absorbed liquid from the absorber 5 to the regenerator 1. The coolant liquid pump 15 is operated to supply the refrigerant vapor from the evaporator 4 to the absorber 5, and the hot water pump 12 is supplied to supply hot water to the load.

By this dilution operation, the rare absorbent liquid is supplied to the regenerator 1 from the absorber 5, so that the concentration of the absorbent liquid in the regenerator 1 is softened, and the regenerator 1 is driven with a drive heat source tube 7. Since no water vapor is supplied from the reactor, almost no refrigerant vapor is separated from the regenerator 1.

The absorbent liquid whose concentration is softened by the regenerator 1 is supplied to the absorber 5 via the absorbent liquid supply pipe 21. Conventionally, since it stopped operation immediately in the case of abnormality, when a concentrated absorbent liquid does not flow from the regenerator 1 to the absorber 5, it stays in the absorbent liquid supply pipe 21 or the heat exchanger 22, and when the stop time becomes long as it is, After cooling, the concentrated absorbent liquid crystallized. In the case of the present invention, since the dilution operation is continued without immediately stopping the operation as described above, it is possible to prevent the crystallization of the absorbent liquid as in the prior art. In addition, prior to the resumption of operation, the operation of dissolving crystals by heating with a heater or the like was required. However, in the case of the present invention, such dissolution is unnecessary because crystallization of the absorbent liquid does not occur.

In the present invention, in order to prevent freezing of the heat source water, when the temperature of the refrigerant liquid stored at the bottom of the evaporator 4 exceeds the predetermined temperature, the dilution operation of the absorbing liquid is performed, and when the temperature is lower than the predetermined temperature, Stop operation.

As shown in FIG. 2, when the flow volume of heat source water falls in step S1, or an interlock abnormality arises in the heat source water pump 18, a dilution operation start signal is output from the control apparatus 23 in step S2. When the flow rate control valve 8 is closed in step S3 and the coolant liquid temperature is 7 ° C. or higher in step S4, the hot water pump 12, the absorbent liquid pump 9, and the coolant liquid pump 15 in steps S5 to S7. ), Dilution operation is performed.

In step S8, it is determined whether or not the dilution is completed. If "NO", the flow returns to step S4 to repeat the dilution operation. Whether or not dilution is completed can be determined by, for example, a timer.

In step S4, when refrigerant | coolant liquid temperature is 7 degrees C or less, it progresses to step S9-S11 and stops the hot water pump 12, the absorption liquid pump 9, and the refrigerant liquid pump 15, respectively, and makes operation stop. Thereby, when the temperature of a refrigerant liquid exceeds predetermined temperature, crystallization of a concentrated absorbent liquid can be prevented by performing dilution operation of an absorbent liquid. In addition, when the temperature of the coolant liquid becomes below the predetermined temperature, the freezing of the heat source water in the heat transfer tube 17 in the evaporator 4 can be suppressed to the maximum by stopping the operation. 3 shows the time chart.

The present invention can be effectively applied as a means for preventing crystallization of absorbent liquid due to partial load when heating is performed with an absorption heat pump.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram in the case of heating operation with the absorption type heat pump by this invention;

Fig. 2 is a flow chart in the case of abnormality in the case of heating operation with the absorption type heat pump according to the present invention;

3 is similarly a time chart at abnormal time.

<Description of the symbols for the main parts of the drawings>

1: regenerator 2: condenser

4: evaporator 5: absorber

7: drive heat source tube 8: flow control valve

9: Absorption liquid pump 10: Rare absorption liquid pipe

11: hot water pipe 12: hot water pump

13: hot water outlet temperature sensor 14: refrigerant liquid supply pipe

15: refrigerant liquid pump 16: refrigerant liquid pipe

17: heat pipe 18: heat source water pump

19: flow rate detection means 20: refrigerant liquid temperature sensor

21: absorption liquid supply pipe 22: heat exchanger

23: controller

Claims (4)

A regenerator for separating the refrigerant vapor by heating the rare absorbent liquid returned from the absorber; A condenser to condense and liquefy the refrigerant vapor conveyed from the regenerator; An evaporator for evaporating the refrigerant liquid conveyed from the condenser; And And the absorber for absorbing the refrigerant vapor conveyed from the evaporator, Dilution of absorbed liquid without immediate operation stop when the flow rate of the heat source water flowing in the heat transfer tube passing through the evaporator during heating operation decreases below a set value or when the heat source water pump installed in the heat transfer tube upstream of the evaporator stops. Absorption heat pump characterized in that the operation. The flow rate detecting means is provided in a heat transfer tube downstream from the evaporator, and the flow rate of the heat source water flowing in the heat transfer tube via the flow rate detection means is adjusted, and the flow rate of the heat source water is equal to or less than a set value. The absorption type heat pump, characterized in that the detection signal is input to the control device when the reduction signal is decreased. The method of claim 1, wherein when the heat source water may be frozen, the temperature of the refrigerant liquid stored at the bottom of the evaporator is measured. When the temperature of the refrigerant liquid exceeds a predetermined temperature, dilution operation of the absorbing liquid is performed. An absorption heat pump characterized in that the operation stops when the temperature is lower than the predetermined temperature. 4. The method according to claim 3, wherein a temperature sensor is provided at the bottom of the evaporator, and the temperature sensor detects the temperature of the refrigerant liquid stored at the bottom of the evaporator and inputs this detection signal to the control device. Absorptive heat pump.

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