KR20090103740A - Absorption heat pump - Google Patents

Abstract

PURPOSE: An absorption heat pump is provided to suppress the temperature rise of the hot water at a warm water gate by reducing the hot water flow rate. CONSTITUTION: A regenerator(1) separates the refrigerant vapor by heating the absorption liquid returned from an absorber(5). A condenser(2) liquidizes the refrigerant vapor transferred from the regenerator. An evaporator(4) evaporates the coolant liquid transferred from the condenser. The absorber absorbs the refrigerant vapor transferred from the evaporator. A hot water entrance temperature sensor(13) is set up at upstream of a warm water pipe(11) passing through the condenser after passing through the absorber. A hot water flow rate of the warm water pipe is reduced, when the hot water entrance temperature sensor detects the prescribed temperature or greater.

Description

Absorption Heat Pump {ABSORPTION HEAT PUMP}

This invention relates to the absorption type heat pump which enabled the operation | movement which the original efficiency as a heat pump was good even when it became a partial load.

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 in 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. When the hot water heated by the absorber passes through the condenser, the hot water is heat-exchanged with the refrigerant vapor transferred from the regenerator, further warmed, and then supplied to a load to serve as a heat source for heating.

In the absorption type heat pump, a hot water outlet temperature sensor for detecting the outlet side temperature of the hot water is installed downstream from the condenser in the hot water pipe, and the temperature of the hot water supplied to the load is detected by the hot water outlet temperature sensor. The flow rate of the driving heat source (main heat source, for example, water vapor discharged from the boiler, etc.) supplied to the regenerator via the flow control valve is controlled so that the temperature of the hot water becomes almost constant.

However, when the load decreases, the heat quantity of the hot water consumed by the load decreases, and even though the hot water outlet temperature sensor maintains a constant temperature, the temperature of the hot water discharged from the load tends to increase. And since the hot water discharged from this load is returned to the inlet side of a hot water pipe, the hot water temperature on the inlet side of the hot water pipe rises.

The increase in the hot water temperature at the hot water pipe inlet side lowers the heat exchange efficiency in the absorber through which the hot water pipe passes. This is because when the hot water having a high temperature passes through the hot water pipe in the absorber, the refrigerant vapor evaporated in the evaporator becomes difficult to be absorbed by the concentrated absorbent liquid sprayed in the absorber, which reduces the amount of heat radiation of the refrigerant vapor generated by the absorption.

In addition, when the refrigerant vapor becomes difficult to be absorbed by the absorber 5, the amount of heat taken away from the heat source water as the sub-heat source passing through the heat transfer tube in the evaporator 4 decreases, making it impossible to effectively use the heat of the sub-heat source. When such a situation arises, the heat pump which draws in sufficient heat from a sub heat source will go against the original purpose of the heat pump which aims at energy saving of a boiler for a main heat source.

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

The present invention has been made in order to solve the problems of the conventional absorption type heat pump, and an object thereof is to provide an absorption type heat pump that suppresses a rise in the temperature of hot water at the inlet side of a hot water pipe even when a partial load is generated during the heating operation. .

As a means for achieving the above object, a first aspect of the invention, the 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 an absorber for absorbing the refrigerant vapor conveyed from the evaporator, and a hot water inlet temperature sensor is installed upstream of the absorber of the hot water pipe passing through the condenser after passing through the absorber. An absorption type heat pump is characterized in that the flow rate of hot water to the hot water pipe is reduced when the sensor detects a predetermined temperature or more.

According to a second aspect of the present invention, in the absorption type heat pump of the first side, a hot water pump is provided upstream from the absorber, and is connected to the hot water pump via a control device by a detection signal from the hot water inlet temperature sensor. The flow rate control is performed by the above.

According to a third aspect of the present invention, in the absorption heat pump of the first side, a flow rate control valve is provided upstream from the absorber, and the flow rate control valve controls the flow rate of hot water to the hot water pipe. It is done.

The fourth side of the present invention is the water absorption type heat pump of any one of the first side to the third side, wherein the hot water flow rate to the hot water pipe when the load of the hot water decreases and the hot water inlet temperature rises. Is gradually reduced, and the hot water flow rate is controlled to be constant when the hot water inlet temperature exceeds a predetermined value.

According to the invention of the first aspect, during the heating operation of the absorption type heat pump, the hot water inlet temperature sensor at the hot water pipe inlet side detects the temperature of the hot water, and when the predetermined temperature or more is detected, the hot water flow rate at the hot water inlet side is decreased. The temperature rise of the hot water at the inlet side can be suppressed. Thereby, even if partial load generate | occur | produces, the high thermal efficiency as an absorption type heat pump can be ensured.

According to the invention of the second aspect, a hot water pump is provided upstream from the absorber, and flow rate control is performed by the hot water pump through a control device by a detection signal from the hot water inlet temperature sensor. The flow rate of hot water supplied can be adjusted suitably.

According to the invention of the third aspect, the flow rate control of the hot water can be performed by a flow rate control valve instead of the inverter control of the hot water pump. That is, a flow rate control valve is provided upstream from the absorber, and the flow rate of the hot water to the hot water pipe can be controlled by the flow rate control valve.

According to the invention of the fourth aspect, when the load of hot water decreases and the hot water inlet temperature rises, the hot water flow rate supplied to the hot water pipe is gradually decreased, and when the hot water inlet temperature exceeds a predetermined value, the hot water flow rate is By controlling to be constant, it is possible to prevent a sudden change in the hot water flow rate to protect the hot water pump and to avoid an abnormal state of the hot water pump due to insufficient flow rate.

1 is a block diagram showing the main portion showing an embodiment of the absorption type heat pump according to the present invention;

2 is a graph showing an example of a hot water flow rate control schedule during partial load of an absorption type heat pump according to the present invention.

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

1: regenerator 2: condenser

4: evaporator 5: absorber

7: driven 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 inlet temperature sensor 14: hot water outlet temperature sensor

15: control unit 16: refrigerant liquid supply pipe

17: refrigerant liquid pump 18: refrigerant liquid pipe

19: heat transfer pipe 20: absorbent liquid supply pipe

21: heat exchanger

Next, the Example of the absorption type heat pump which concerns on this invention is described based on drawing. 1 is a configuration diagram of main parts showing an embodiment of an absorption type heat pump according to the present invention. In Fig. 1, reference numeral 1 denotes a regenerator, and reference numeral 2 denotes a condenser, and these are housed in the upper body 3, and the lower portion 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, for example, steam or hot water discharged from a boiler or an engine can be used.

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 filter.

The refrigerant vapor separated from the rare water absorbing liquid in the regenerator 1 flows into the condenser 2 adjacent to it, cools it, condenses it, and is stored at the bottom of the condenser 2. The condenser 2 is piped so that the hot water pipe 11 passes, and the hot water pipe 11 passes through the condenser 2 after passing through the absorber 5. Moreover, the hot water pump 12 is provided upstream from the absorber 5 in the hot water pipe 11, and the hot water which detects the temperature of the hot water in the hot water pipe inlet side between this hot water pump 12 and the absorber 5 is provided. An inlet temperature sensor 13 is provided, and a hot water outlet temperature sensor 14 that detects the temperature of the hot water at the hot water pipe outlet side is provided downstream from the condenser 2.

Numeral 15 denotes a control device, in which a detection signal from the hot water inlet temperature sensor 13 is input, and a control signal is output from the control device 15 to the hot water pump 12 to control the flow rate. . In addition, the hot water pump 12 may control the frequency of the pump by phase control or the like.

The refrigerant liquid stored at the bottom of the condenser 2 is supplied to the evaporator 4 by the refrigerant liquid supply pipe 16, is stored at the bottom of the evaporator 4, and at the same time, the refrigerant liquid pump 17. Is supplied to the spreader 4a provided in the upper part of the evaporator 4 via the refrigerant liquid pipe 18, and spreads. In this evaporator 4, the heat exchanger tube 19 is piped so that the heat source water flows through this heat exchanger tube 19 as a sub-heat source.

The absorbent liquid (hereinafter referred to as "concentrated absorbent liquid") whose concentration is increased by separating the refrigerant vapor by the regenerator 1 is supplied to the absorber 5 by the absorbent liquid supply pipe 20, and the absorber 5 It spreads from the spreader 5a provided in the upper part. A heat exchanger 21 is provided in the middle of the absorbent liquid supply pipe 20, and the rare water absorbing tube 10 passes through the heat exchanger 21 to exchange heat between the hot concentrated absorbent liquid and the cold rare absorbent liquid. As a result, since the concentrated absorbent liquid is cooled and supplied to the absorber 5, the concentrated absorbent liquid easily absorbs the refrigerant vapor from the evaporator 4 when sprayed from the sprayer 5a, and the rare absorbent liquid becomes warm to the regenerator 1. Since it is supplied, the drive heat source for separating the refrigerant vapor can be reduced.

The absorption heat pump according to the present invention configured as described above supplies steam to the drive heat source tube 7 as a heat source for driving, for example, as a heat source for heating, and at the same time as a sub-heat source to the heat pipe 19. For example, heat source water is supplied.

In this heating operation, the rare water absorbing liquid in the regenerator 1 is heated by steam supplied to the driving heat source tube 7 as described above to separate the refrigerant vapor. The refrigerant vapor separated from the regenerator 1 flows into the neighboring condenser 2, radiates the hot water pipe 11 in the condenser 2 to the hot water flowing therein, and becomes a refrigerant liquid to the bottom of the condenser 2. Is stored.

The coolant liquid stored at the bottom of the condenser 2 is supplied to the evaporator 4 by the coolant liquid supply pipe 16, and is also spreader 4a via the coolant liquid pipe 18 by the coolant liquid pump 17. ) Is sprayed toward the heat transfer pipe 19. The sprinkled refrigerant liquid takes heat from the heat source water flowing through the heat transfer tube 19 and evaporates to become refrigerant vapor and flows into the neighboring absorber 5.

The refrigerant vapor introduced into the absorber 5 is supplied from the regenerator 1 to the absorber 5 by the absorbent liquid supply pipe 20, 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 is returned to the regenerator 1 after being heated in the heat exchanger 21 through the rare absorbent liquid tube 10 by the absorbent liquid pump 9. .

In this way, the coolant and the absorbent liquid are circulated by the circuit, respectively, and the hot water passing through the hot water pipe 11 is heated by heat exchange with the refrigerant vapor absorbed by the concentrated absorbent liquid when passing through the absorber 5 and then condensed ( When passing through 2), heat is exchanged with the refrigerant vapor supplied from the regenerator 1 and re-heated, and supplied to a load such as an indoor unit (not shown) and used as a heating heat source. The hot water heat-exchanged by the load and the temperature dropped is discharged from the load and returned to the inlet side of the hot water pipe 11 through a circulation circuit (not shown).

When the load decreases during the heating operation of the absorption heat pump, control is performed to reduce the supply amount of the driving heat source so that the hot water outlet temperature is not too high. However, as described above, the hot water discharged from the load is returned to the inlet side of the hot water pipe 11. Since it is a losing structure, the temperature of the hot water at the inlet side rises. As described above, when the hot water inlet temperature rises, the heat exchange efficiency in the absorber 5 through which the hot water pipe 11 passes is lowered. That is, when the hot water having risen in temperature passes through the absorber 5, the refrigerant vapor evaporated in the evaporator 4 becomes difficult to be absorbed by the concentrated absorbent liquid sprayed by the absorber 5, and thus, the refrigerant vapor with respect to the hot water pipe 11. The heat dissipation amount is reduced.

In addition, when the refrigerant vapor becomes difficult to be absorbed by the absorber 5, the generation of the refrigerant vapor in the evaporator 4 is inhibited, so that the amount of heat taken as heat of evaporation from the heat source water flowing through the heat transfer tube 19 is reduced. For this reason, the effective use of the sub-heat source reduces the amount of water vapor as the driving heat source supplied to the regenerator 1, thereby making it impossible to achieve the purpose of saving use heat energy in a boiler or the like. Absorption heat pumps improve heat efficiency by spreading heat from the heat source water. However, as described above, when the heat efficiency of the sub-heat source decreases due to an increase in the temperature of the hot water inlet, it is not possible to save the driving heat source and function as a heat pump. It will not be enough.

In the present invention, the rise of the hot water inlet temperature at the time of reducing the load is prevented so that such a situation does not occur. As the means, when the hot water inlet temperature sensor 13 detects a predetermined temperature or more, the flow rate of the hot water to the hot water pipe 11 is reduced.

2 is a graph showing an example of a hot water flow rate control schedule at partial load. In this case, for example, the rated hot water inlet temperature is set to 40 ° C. and the hot water outlet temperature is set to 80 ° C., and when the hot water inlet temperature sensor 13 detects 40 ° C. or more as a partial load, this detection signal is detected. Is input to the control device 15, and a control signal is output from the control device 15 to the hot water pump 12. In response to the control signal from the control device 15, the hot water pump 12 performs flow rate control to gradually reduce the flow rate of the hot water to the inlet of the hot water pipe 11.

When the hot water inlet temperature sensor 13 detects 60 ° C. or more from this state, this detection signal is input to the control device 15, and a control signal is supplied from the control device 15 to the hot water pump 12. It outputs and hold | maintains the flow volume of hot water to the inlet of hot water pipe 11 uniformly.

In the control in this case, the hot water inlet temperature was expected to be 70 ° C. at 25% of the load, but the hot water inlet temperature could be lowered to 60 ° C. by reducing the flow rate of the hot water supplied to the hot water pipe 11 as described above. . Thereby, it turned out that the load condition which can operate an absorption type heat pump appropriately is expanded, and the operation | movement which is inherently efficient is possible. The hot water flow rate is not narrowed to less than 50% in order to prevent a sudden change in the hot water flow rate to protect the hot water pump 12 and to avoid abnormality of the hot water pump 12 due to insufficient flow rate.

In this way, if the flow rate of the hot water supplied to the inlet of the hot water pipe 11 during partial load decreases, the temperature of the hot water discharged from the load decreases, and the hot water from which the temperature is dropped is returned to the inlet side of the hot water pipe 11. Therefore, the temperature rise of the hot water at the inlet side of the hot water pipe 11 can be suppressed. Thereby, even when it becomes a partial load during the heating operation of an absorption type heat pump, it becomes possible to spread | fever heat from the heat source water of a sub heat source, and the operation | movement with the inherent efficiency of the absorption type heat pump becomes possible.

In the above embodiment, the hot water pump 12 is used as a means for controlling the hot water flow rate, but the flow rate is not limited thereto. For example, a flow rate control valve (not shown) is provided on the upstream side of the absorber 5, and this flow rate The control valve may be configured to control the flow rate of the hot water supplied to the inlet side of the hot water pipe 11.

The present invention can be applied very effectively when a single-use absorption heat pump is used for heating operation.

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, After passing through the absorber, a hot water inlet temperature sensor is provided upstream from the absorber of the hot water pipe passing through the condenser, and when the hot water inlet temperature sensor detects a predetermined temperature or more, the flow rate of hot water to the hot water pipe is measured. Absorption heat pump, characterized in that for reducing. The absorption type heat pump according to claim 1, wherein a hot water pump is provided upstream from the absorber, and flow rate control is performed by the hot water pump via a control device by a detection signal from the hot water inlet temperature sensor. The absorption type heat pump according to claim 1, wherein a flow rate control valve is provided upstream from the absorber, and the flow rate control valve controls the flow rate of hot water to the hot water pipe. The hot water flow rate to the hot water pipe is gradually decreased when the load of the hot water decreases and the hot water inlet temperature rises, and the hot water inlet temperature exceeds a predetermined value. At one time, the absorption type heat pump, characterized in that the control so that the flow rate of the hot water is constant.