JPH046857B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to an improvement in an absorption heat pump that uses heat radiation from the heat radiation side of an absorption refrigeration cycle, that is, an absorber and a condenser, to raise the temperature of a fluid to be heated, such as hot water.

(b) Prior art and its problems Absorption heat pumps that raise the temperature of the heated fluid by using the heat dissipation effect of the absorber and condenser have drive energy, in other words, the heat output of the heated fluid relative to the heating input to the generator. It has a high ratio (i.e. coefficient of performance) and has the advantage of being able to efficiently raise the temperature of the heated fluid, but if the temperature of the heat source fluid supplied to the evaporator becomes too low or the supply amount of the heat source fluid is insufficient, evaporation will occur. The refrigerant vaporization effect in the absorber becomes insufficient, and in extreme cases, the vapor pressure on the absorber side (saturated vapor pressure of the absorption liquid sprayed in the absorber) becomes higher than the vapor pressure on the evaporator side, causing the refrigerant to evaporate. There is a problem in that steam moves from the absorber to the evaporator and condenses in the evaporator, that is, a reverse heat radiation phenomenon occurs from the heated fluid to the heat source fluid, and the temperature of the heated fluid flowing into the absorber increases. If it is too low to cause a reverse heat dissipation phenomenon, there will be problems such as crystallization of the absorption liquid and freezing of the refrigerant. As described above, conventional absorption heat pumps of this type have the problem that if the temperature or flow rate of the heat source fluid supplied to the evaporator drops too much, the temperature of the heated fluid cannot be raised safely and stably. .

(C) Means for Solving the Problems In view of the above problems, the present invention provides, in this type of absorption heat pump, when the heat source fluid supplied to the evaporator falls below the set temperature or set flow rate, the evaporator is The refrigerant liquid that is sprayed on the stored heat source tubes and the absorption liquid that is sprayed on the heated tubes that are stored in the absorber are
flowing through the refrigerant bypass pipe and the solution bypass pipe, respectively;
By adopting a switching means that circulates the heat source tube and the heated tube in a bypass manner, it is possible to prevent the above-mentioned reverse heat dissipation phenomenon, crystals of the absorption liquid, freezing of the refrigerant, etc., while preventing them from occurring. The present invention provides an absorption heat pump that can safely and stably raise the temperature of a fluid to be heated in the condenser using the heat of refrigerant vapor flowing into the condenser from the condenser.

(d) Embodiment The drawing is a schematic configuration diagram showing an embodiment of the present invention, in which 1 is a generator equipped with a combustion burner 2, and 3 is a generator that heats and separates the refrigerant from a dilute liquid and regenerates it into a concentrated liquid. 4 is a separator that separates the gas and liquid from 1 into concentrated liquid and refrigerant vapor; 4 is a condenser that cools and condenses the refrigerant vapor from separator 3 with the heated fluid in the heated tube 5 housed in the container; 6 is an evaporator that circulates and vaporizes the refrigerant liquid in a refrigerant reservoir 7 provided at the lower part of the vessel through a heat source tube 9 housed in the vessel using a bubble pump 8; 11 is a solution heat exchanger, and 11 is a solution heat exchanger, and 11 is a solution heat exchanger. 13. A dilution tube 15 having a solution pump 14; a refrigerant liquid down-flow pipe 17 that passes the condensed refrigerant liquid through the bubble pump 8 and then leads it to the refrigerant distributor 16; a refrigerant liquid that leads the refrigerant liquid in the refrigerant reservoir 7 to the bubble pump 8; pipe 18 , a refrigerant liquid riser pipe 19 that sends the refrigerant liquid to the refrigerant distributor 16 by the bubble pump 8;
and are connected by a refrigerant vapor conduit 20 to form a circulation cycle of refrigerant and absorption liquid.

Reference numeral 21 denotes a solution bypass pipe that is branched from the concentrated liquid pipe 13 and connected to the bottom of the absorber 10 so that the concentrated liquid sprayed onto the heated pipe 5 bypasses the heated pipe. is equipped with an on-off valve V ₁ , and
The concentrated liquid pipe 13 on the way from the concentrated liquid branch point to the solution disperser 22 is also provided with an on-off valve V ₂ . 23 is
The refrigerant liquid reservoir 7 is arranged so that the refrigerant liquid sprayed onto the heat source pipe 9 by the bubble pump 8 bypasses the heat source pipe.
A refrigerant bypass pipe connects the solution reservoir 24 and the refrigerant bypass pipe, and the pipe is equipped with an on-off valve _V3 . S is a temperature detector (or flow rate detector) provided in the heat source tube 9
According to the signal from the detector, when the heat source fluid is below the set temperature (or set flow rate), the on-off valve is activated.
V ₁ and V ₃ are opened and on-off valve V ₂ is closed, and when the heat source fluid is higher than the set temperature (or higher than the set flow rate), the on-off valves V ₁ and V ₃ are closed and on-off valve V ₂ is opened. It is possible to switch as follows.

In the absorption heat pump having such a configuration, when the energy of the heat source fluid supplied to the evaporator 6 becomes insufficient and the refrigerant vaporization effect in the evaporator 6 becomes insufficient, the concentrated water that has been sprayed on the heated tubes 5 As the liquid flows through the solution bypass pipe 21, the refrigerant liquid that had been sprayed in the heat source pipe 9 flows through the refrigerant bypass pipe 23, and the refrigerant vaporization action in the evaporator 6 and the refrigerant absorption action in the absorber 10 are stopped. The heated fluid flowing through the heated tube 5 is heated in the condenser 5 by the heat of the refrigerant vapor flowing from the generator 1 through the separator 3. That is, the saturated vapor pressure of the absorption liquid sprayed on the heated tube 5 of the absorber 10 becomes higher than the refrigerant vapor pressure of the evaporator 6, and the refrigerant vapor moves from the absorber 10 side to the evaporator 6 side, and the evaporator In other words, the circulation cycle of the refrigerant and absorption liquid is switched to prevent the phenomenon of condensation in the heat source tube 9, in which the heat of the heated fluid is released to the heat source fluid. This is a transition to

In addition, if the heat source fluid supply temperature drops too much or the supply amount is too small, even if the temperature of the heated fluid flowing into the absorber 10 becomes low, the absorber 1
If the refrigerant absorption action continues at 0, the internal pressure of the evaporator 6 and absorber 10 will decrease, causing problems such as freezing of the refrigerant, freezing of the heat source fluid, and crystallization of the absorption liquid. In the refrigerator,
Since the refrigerant absorption action of the absorber 10 and the refrigerant vaporization action of the evaporator 6 are stopped before the supply temperature or supply amount of the heat source fluid drops too much, these disadvantages are also prevented. Furthermore, the refrigerant liquid in the refrigerant liquid reservoir 7 is mixed with the absorbent liquid in the solution reservoir 24, and the concentration of the absorbent liquid returned to the generator 1 becomes diluted, so that the boiling temperature of the absorbent liquid in the generator becomes low, resulting in the so-called Another advantage is that it saves energy needed to heat up the absorption liquid during boiler operation.

Note that the bypass path for the refrigerant liquid is not limited to the one shown in the figure, and for example, a pipe (not shown) connecting the refrigerant liquid pipe 18 and the suction side of the solution pump 14 of the dilution tube 15, or a bypass path for directing the condensed refrigerant liquid to the solution reservoir 24. It may be replaced with a pipe (as shown in the figure) or a combination of these pipes, and the circulation cycle switching mechanism is not limited to that shown in the figure. The opening and closing of the on-off valves V ₁ , V ₂ and V ₃ may be switched by a signal from a sensing detector (not shown), or the on-off valves V ₁ , V ₂ may be switched between opening and closing.
A three-way valve (not shown) may be used instead.

Furthermore, in the case of an absorption heat pump that pumps refrigerant liquid from a bubble pump 8 as shown in the figure, the condenser 4
During boiler operation, when the pressure difference between the air bubble pump 8 and the evaporator 6 becomes smaller, the liquid pumping power of the bubble pump 8 decreases and the flow of the refrigerant liquid decreases significantly. It is particularly useful to provide a refrigerant bypass path because the circulating absorbent liquid becomes increasingly overconcentrated and tends to crystallize.

On the other hand, in the absorption heat pump having such a configuration, when there is sufficient energy in the heat source fluid supplied to the evaporator 6, in other words, when the temperature and flow rate of the heat source fluid are higher than the set values, the detector The on-off valves V ₁ and V ₃ are closed by the signal S,
The on-off valve _V2 is opened, and a so-called heat pump operation is performed in which the temperature of the fluid to be heated is raised by heat radiation due to the refrigerant absorption action of the absorber 10 and heat radiation due to the refrigerant condensation action of the condenser 5. Note that the set temperature or set flow rate of the heat source fluid is appropriately determined according to the specifications of the absorption heat pump. The detector S may be one that senses both the temperature and flow rate of the heat source fluid.

In addition, in the event that an abnormality occurs such as dry firing in the generator 1 or locking of the solution pump 14 due to crystal formation in any part of the absorption liquid circulation system, the on-off valves V ₁ , V ₂ ,
It is preferable to dilute the absorption liquid by opening _V3 . Furthermore, it is desirable to open the on-off valves V ₁ , V ₂ , and V ₃ to perform a so-called absorption liquid dilution operation prior to stopping operation of the absorption heat pump.

(e) Effects of the invention As described above, in the absorption heat pump of the present invention, the heat source fluid flowing through the heat source tube housed in the evaporator is
When the set temperature and flow rate are exceeded and there is sufficient energy, efficient so-called absorption heat pump operation is performed to raise the temperature of the heated fluid, and when the heat source fluid falls below the set temperature or flow rate, the refrigerant liquid and absorption Since the liquid flows through the refrigerant bypass path and the solution bypass path to transition from so-called absorption heat pump operation to boiler operation, there may be a reverse heat radiation phenomenon from the heated fluid to the heat source fluid, freezing of the refrigerant, or absorption liquid This has the effect of safely and stably raising the temperature of the fluid to be heated while preventing the occurrence of harmful effects such as crystals.

[Brief explanation of drawings]

The drawing is a schematic explanatory diagram of a circuit configuration showing an embodiment of the present invention. 1... Generator, 4... Condenser, 5... Heated tube, 6... Evaporator, 8... Bubble pump, 9... Heat source tube, 10... Absorber, 11... Solution heat exchanger ,
21...Solution bypass pipe, 23...Refrigerant bypass pipe, S...Detector, _V1 , _V2 , _V3 ...Opening/closing valve.

Claims (1)

[Claims] 1 A generator, condenser, evaporator, absorber, and solution heat exchanger are connected via piping to form a circulation cycle of refrigerant and absorption liquid, and the superheated fluid in the heated pipes housed in the absorber and condenser is elevated. In an absorption heat pump that heats up, there is a solution bypass path that is provided in the absorption liquid path between the absorber and the solution heat exchanger and bypasses the heated tube of the absorber, and a refrigerant liquid reservoir of the evaporator or a condenser. A refrigerant bypass path is provided in the refrigerant liquid path between the evaporator and bypasses the heat source tube housed in the evaporator, and a solution bypass path is provided when the heat source fluid flowing in the heat source tube falls below the set temperature or flow rate. An absorption heat pump characterized by comprising a mechanism for flowing an absorption liquid and a refrigerant liquid into a passage and a refrigerant bypass passage.