JPH07318191A - Absorption type heat pump equipment - Google Patents

Abstract

PURPOSE:To make capacity and efficiency higher than usual ones in absorption type heat pump equipment wherein a boiling point difference between a refrigerant being a working medium and an absorbent is small and which necessitates a rectifier. CONSTITUTION:Part of a thick solution is made to flow into the upper part of a rectifier 3. A heat exchanger 10 is provided in the upper part of the rectifier 3 and the thick solution flowing in flows through the heat exchanger 10. On the occasion, the solution is subjected to heat exchange without being brought into direct contact with refrigerant vapor rising outside the heat exchanger 10. The lower part of the heat exchanger 10 is opened and the thick solution flows out into the middle part of a packing layer 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption heat pump device which utilizes hot and cold heat obtained by pumping heat from a low temperature heat source using city gas, solar heat or the like as an energy source, and particularly a refrigerant as a working medium. And a small difference in the boiling point of the absorbent, and to the improvement of the device requiring a rectifier.

[0002]

2. Description of the Related Art The structure of a conventional absorption heat pump device is shown in FIG.

A solution having a high refrigerant concentration (hereinafter referred to as a concentrated solution) pressurized by the solution pump 1 is branched into two, one of which flows into the solution heat exchanger 2 and the other of which flows out of the rectifier 3 here. The temperature of the solution is increased by receiving the sensible heat of the coming solution having a low refrigerant concentration (hereinafter referred to as a dilute solution).

The other concentrated solution branched into two (hereinafter referred to as a branched concentrated solution) directly flows into the upper portion of the rectifier 3 without passing through the solution heat exchanger 2.

The concentrated solution heated in the solution heat exchanger 2 is externally heated in the refrigerant vapor generator 4 to generate refrigerant vapor,
It flows into the lower part of the rectifier 3 in a gas-liquid two-phase state.

Inside the rectifier 3, there is provided a packing layer 5 filled with metal pieces having many gaps such as lariching for the purpose of increasing the contact area between the branched concentrated solution and the refrigerant vapor.

In the lower part of the rectifier 4, due to the difference in density, the generated refrigerant vapor flows upward and the dilute solution in which the refrigerant has become less flows downward to separate gas and liquid.

The refrigerant vapor rising inside the rectifier 4 exchanges heat while directly contacting the branched concentrated solution flowing from the upper part of the rectifier 4.

Therefore, the branched concentrated solution receives heat from the refrigerant vapor and flows down while raising the temperature, and drops to the lower portion of the rectifier 3 while partially producing the refrigerant vapor.

Further, the temperature of the rising refrigerant vapor is lowered and the solution having a low refrigerant concentration is condensed, so that the purity is increased.

Then, the highly purified refrigerant vapor flows out from the upper part of the rectifier 3 to the condenser 6, where heat is discharged to the outside to be liquefied. After that, the pressure is reduced by the expansion valve 8 and the temperature becomes low to enter the evaporator 9, receives heat from the outside to evaporate, and returns to the absorber 7.

On the other hand, the dilute solution in which the amount of the refrigerant has decreased flows out to the solution heat exchanger 2, where the dilute solution gives its sensible heat to the concentrated solution to lower the temperature, and then the absorber is passed through the pressure reducing valve 11 to the absorber. Return to 7.

In the absorber 7, the refrigerant vapor is absorbed by the dilute solution to form a concentrated solution, and the absorption heat generated at that time is discharged to the outside.

When the absorption heat pump is used for cooling or freezing, the cold heat of the evaporator 9 is used, and when it is used for heating or hot water supply, the hot heat of the condenser 6 and the absorber 7 is used.

[0015]

However, such a conventional absorption heat pump is still insufficient for increasing the purity of the refrigerant flowing out from the upper part of the rectifier 3,
There is a problem that the capacity and efficiency of the heat pump are lowered.

This problem will be described more specifically with reference to FIG.

FIG. 5 shows an equilibrium state in two phases of gas and liquid, and shows the relationship between concentration and temperature under a constant pressure.

In the figure, the curve S _L on the left side shows the equilibrium liquid line, and the curve S _V on the right side shows the equilibrium vapor line. Point A shows the state of the branched concentrated solution flowing from the upper part of the rectifier 3, and point B shows the state of the refrigerant vapor flowing from the lower part of the rectifier 3.

The branched concentrated solution flows into the rectifier 3 at the concentration ξa% and the temperature Ta, and the refrigerant vapor flows into the rectifier 3 at the concentration ξb% and the temperature Tb. At this time, the refrigerant vapor is almost in equilibrium, but the branched concentrated solution is in a supercooled state.

The refrigerant vapor gives heat to the branched concentrated solution while rising in the rectifier 3 to lower the temperature and change along the equilibrium vapor line S _V , so that the equilibrium concentration rises as the temperature drops. .

At this time, a solution having a low refrigerant concentration (a liquid containing more absorbent than refrigerant vapor) is condensed, and the purity of the refrigerant is increased. When the refrigerant is cooled to the temperature Tc, the predetermined refrigerant concentration ξc
The purity is increased to the level and the product flows out from the upper part of the rectifier 3.

On the other hand, in the upper portion of the rectifier 3, the condensed refrigerant vapor comes into contact with the above-mentioned supercooled branched concentrated solution.

Since the liquid side saturation concentration corresponding to the refrigerant vapor concentration ξc% at the temperature Tc is ξc '%, in order to obtain the refrigerant vapor concentration ξc%, the concentration of the branched concentrated solution is ξc%.
It is necessary to raise it to c '%.

Therefore, the branched concentrated solution needs to absorb a large amount of refrigerant vapor and changes in the direction of arrow E. As a result, the amount of refrigerant flowing out from the upper portion of the rectifier 3 is reduced, and the heat pump capacity and efficiency are reduced.

An object of the present invention is to solve the above-mentioned problems and to provide an absorption heat pump device with high efficiency and high efficiency.

[0026]

The present invention adopts the following constitution in order to achieve the above object.

In the first aspect of the present invention, a heat exchanger is installed in the upper part of the rectifier for only heat exchange without directly contacting the branched concentrated solution with the generated refrigerant vapor, and after heat exchange with the refrigerant vapor, The branched concentrated solution was made to flow down into the lower part of the rectifier.

In the second aspect of the invention, a heat exchanger for cooling water and refrigerant vapor is installed in the upper part of the rectifier, and the branched concentrated solution is made to flow into the rectifier from below the heat exchanger.

In the third invention, a heat exchanger for the refrigerant vapor flowing out of the evaporator and the refrigerant vapor rising in the rectifier is installed in the upper part of the rectifier, and the branched concentrated solution is introduced from below the heat exchanger. Was made to flow into the rectifier.

[0030]

In any of the above-mentioned first to third inventions, the heat exchanger is installed above the rectifier, and the heat exchanged fluid whose temperature is lower than that of the refrigerant vapor is placed in the heat exchanger. Since the refrigerant flows, the refrigerant vapor and the heat exchange fluid do not come into direct contact with each other, and only heat exchange is performed.

Therefore, in FIG. 5, the refrigerant vapor is cooled without being absorbed by the concentrated solution, and the purity can be increased along the equilibrium vapor line S _V.

In particular, when the fluid to be heat exchanged is a concentrated solution, the temperature is raised to a temperature Td which is the boiling point of the concentration ξa% or more by a heat exchanger, and then it is made to flow to the lower part of the rectifier to branch. The concentrated solution can be heated in the direction of arrow F.

Further, the concentration of the refrigerant vapor flowing out from the rectifier greatly varies depending on the flow rate of the refrigerant vapor and the temperature condition of the two-phase flow flowing into the rectifier (the refrigerant concentration is determined by the temperature under the same pressure). Be done). Moreover, since the concentration of the refrigerant vapor is more affected by the temperature fluctuation than the pressure fluctuation, if the temperature near the inlet of the branched concentrated solution of the rectifier is kept constant, the concentration of the refrigerant vapor is kept constant. It is possible to For that purpose, it is possible to control the concentration of the refrigerant flowing from the upper part of the rectifier by changing the flow rate of the branched concentrated solution.

Therefore, the capacity and efficiency of the absorption heat pump device are further enhanced.

[0035]

EXAMPLE 1 FIG. 1 is a block diagram of an absorption heat pump device according to Example 1 of the present invention.

The concentrated solution having a high refrigerant concentration which is pressurized by the solution pump 1 is branched into two, one of which flows into the solution heat exchanger 2 and the concentration of the refrigerant which flows out from the rectifier 3 there. The temperature rises by receiving the sensible heat of a dilute solution with a low

The other concentrated solution, which is branched into two, flows into the upper part of the rectifier 3 with the flow rate controlled by the flow rate adjusting valve 12.

On the other hand, the concentrated solution heated by the solution heat exchange 2 is
The refrigerant vapor generator 4 is externally heated to generate refrigerant vapor, which flows into the lower portion of the rectifier 3 in a gas-liquid two-phase state.

At the bottom of the rectifier 3, due to the difference in density,
The generated vapor flows upward, and the dilute solution depleted in the refrigerant flows downward to separate gas and liquid.

Inside the rectifier 3, for the purpose of increasing the contact area between the branched concentrated solution flowing down and the rising refrigerant vapor,
A filling layer 5 is provided which is filled with metal pieces having many gaps such as Rarich rings.

Therefore, the ascending refrigerant vapor flows between the packed beds 5 in the rectifier 3.

The feature of the first embodiment is that a heat exchanger 10 is provided in the upper part of the rectifier 3 and the branched concentrated solution is introduced into the heat exchanger 10.

In order to increase the contact area with the refrigerant vapor, this heat exchanger 10 is formed in a spiral shape in this example, and its lower portion is open.

Therefore, the branched concentrated solution flowing inside the heat exchanger 10 receives heat from the refrigerant vapor rising outside the heat exchanger 10 to raise its temperature, and reaches the boiling point or more at the outlet of the heat exchanger 10. And flows into the middle portion of the packed bed 5.

On the other hand, the temperature of the refrigerant vapor that rises and rises is lowered, and at the same time, the equilibrium solution having a low refrigerant concentration (conversely, a large amount of absorbent) is condensed, so that the purity is increased.

Then, the highly purified refrigerant vapor flows out from the upper portion of the rectifier 3 to the condenser 6.

The high-purity refrigerant vapor flowing out from the upper portion of the rectifier 3 radiates heat to the outside in the condenser 6 to be liquefied, is decompressed by the expansion valve 8 and becomes a low temperature, enters the evaporator 9, and enters from the outside. It receives heat, evaporates, and returns to the absorber 7.

On the other hand, the liquid condensed from the refrigerant vapor flows down in the packed bed 5 to exchange heat and substance with the ascending refrigerant vapor, and when it flows down to the lower part of the heat exchanger 10, it is filled with the branched concentrated solution. After flowing down in the layer 5, heat and mass exchange are performed with the rising refrigerant vapor.

These liquids are mixed with the liquid flowing from the refrigerant vapor generator 4 in the lower portion of the rectifier 3 while reducing the concentration while generating the refrigerant vapor of equilibrium concentration, and become a dilute solution. After flowing out to the heat exchanger 2, the dilute solution gives its sensible heat to the concentrated solution to lower the temperature, and then the absorber 7 via the pressure reducing valve 11.
Return to.

As described above, the refrigerant vapor rising inside the rectifier 3 flows without being absorbed in a large amount by the flowing solution.

In the absorber 7, the refrigerant vapor is absorbed in the dilute solution,
The absorption heat generated at that time is discarded to the outside.

When the absorption heat pump device is used for cooling or freezing, the cold heat of the evaporator 9 is used, and when it is used for heating or hot water supply, the hot heat of the condenser 6 and the absorber 7 is used.

The concentration of the refrigerant vapor flowing out from the rectifier 3 is
It greatly varies depending on the flow rate of the refrigerant vapor and the temperature condition of the two-phase flow flowing into the rectifier.

However, by adjusting the opening of the flow rate adjusting valve 12 so as to keep the temperature at the outlet of the rectifier constant and changing the flow rate of the branched concentrated solution flowing into the rectifier 3, the rectifier 3 is changed. It is also easy to control the refrigerant concentration at the outlet of the.

As described above, since the high-purity refrigerant vapor can be obtained without decreasing, the capacity and efficiency of the absorption heat pump device are further enhanced.

Embodiment 2 FIG. 2 is a block diagram of an absorption heat pump device according to Embodiment 2 of the present invention.

The concentrated solution having a high refrigerant concentration which is pressurized by the solution pump 1 is branched into two, one of which flows into the solution heat exchanger 2 and the concentration of the refrigerant which flows out from the rectifier 3 there. The temperature rises by receiving the sensible heat of a dilute solution with a low

Further, the flow rate of the other branched concentrated solution branched into two is controlled by the flow rate adjusting valve 12, and flows into the central portion of the rectifier 3.

On the other hand, the concentrated solution heated by the solution heat exchange 2 is
The refrigerant vapor generator 4 is externally heated to generate refrigerant vapor, which flows into the lower portion of the rectifier 3 in a gas-liquid two-phase state.

At the bottom of the rectifier 3, due to the difference in density,
The generated vapor flows upward, and the dilute solution depleted in the refrigerant flows downward to separate gas-liquid.

Inside the rectifier 3, there is provided a packing layer 5 which is filled with metal pieces having many gaps such as Rarich rings for the purpose of increasing the contact area between the flowing solution and the rising refrigerant vapor. There is.

Therefore, the ascending refrigerant vapor flows between the packed beds 5 in the rectifier 3.

The feature of the second embodiment is that the heat exchanger 10 is provided above the rectifier 3 and cooling water is supplied into the heat exchanger 10, while the heat exchanger 10 in the rectifier 3 is supplied. It is configured such that the concentrated solution that has passed through the flow rate adjusting valve 12 flows into the lower position of.

This heat exchanger 10 is formed in a spiral shape in this example in order to increase the contact area with the refrigerant vapor.

The cooling water flowing in the heat exchanger 10 cools the refrigerant vapor rising outside the heat exchanger 10, so that the refrigerant vapor is cooled and the refrigerant concentration in equilibrium at the temperature at that time is low. Concentrates the solution (if it has a lot of absorbent), increasing the purity.

Then, the highly purified refrigerant vapor flows out from the upper part of the rectifier 3 to the condenser 3.

The high-purity refrigerant vapor flowing out from the upper part of the rectifier 3 discards heat to the outside in the condenser 6 to be liquefied, is decompressed by the expansion valve 8 and becomes a low temperature, and enters the evaporator 9 to be discharged from the outside. It receives heat, evaporates, and returns to the absorber 7.

On the other hand, the liquid condensed from the refrigerant vapor flows down in the packed bed 5 to exchange heat and substances with the ascending vapor, and when it flows down to the central portion of the heat exchanger 10, the inflowing concentrated solution. At the same time, heat and substance exchange are performed with the refrigerant vapor flowing down in the packed bed 5 and rising.

These liquids are mixed with the liquid flowing from the refrigerant vapor generator 4 in the lower part of the rectifier 3 while reducing the concentration while generating vapors of equilibrium concentration, and become a dilute solution to heat the solution. It flows out to the exchanger 2, where the dilute solution gives its sensible heat to the concentrated solution to lower the temperature, and then returns to the absorber 7 via the pressure reducing valve 11.

As described above, the refrigerant vapor rising inside the rectifier 3 flows without being absorbed in a large amount by the flowing solution.

In the absorber 7, the refrigerant vapor is absorbed in the dilute solution,
The absorption heat generated at that time is discarded to the outside.

When the absorption type heat pump device is used for cooling or freezing, the cold heat of the evaporator 9 is used, and when it is used for heating or hot water supply, the hot heat of the condenser 6 and the absorber 7 is used.

As described above, since the high-purity refrigerant vapor can be obtained without decreasing, the capacity and efficiency of the absorption heat pump device are further enhanced.

Third Embodiment FIG. 3 is a block diagram of an absorption heat pump device according to a third embodiment of the present invention.

The concentrated solution having a high refrigerant concentration, which is pressurized by the solution pump 1, is branched into two, one of which flows into the solution heat exchanger 2 and the concentration of the refrigerant which flows out from the rectifier 3 there. The temperature rises by receiving the sensible heat of a dilute solution with a low

Further, the flow rate of the other branched concentrated solution branched into two is controlled by the flow rate adjusting valve 12, and flows into the central portion of the rectifier 3.

On the other hand, the concentrated solution heated by the solution heat exchange 2 is
The refrigerant vapor generator 4 is externally heated to generate refrigerant vapor, which flows into the lower portion of the rectifier 3 in a gas-liquid two-phase state.

At the bottom of the rectifier 3, due to the difference in density,
The generated vapor flows upward, and the dilute solution depleted in the refrigerant flows downward to separate gas-liquid.

Inside the rectifier 3, there is provided a packing layer 5 which is filled with metal pieces having many gaps such as Rarich rings for the purpose of increasing the contact area between the flowing solution and the rising refrigerant vapor. There is.

Therefore, the ascending refrigerant vapor flows between the packed beds 5 in the rectifier 3.

The feature of the third embodiment is that a heat exchanger 10 is provided above the rectifier 3, and the heat exchanger 10 supplies the low-pressure refrigerant evaporated in the evaporator 10 into the heat exchanger 10 for heat exchange. Bowl 1
The refrigerant passing through 0 is connected so as to flow out to the absorber 7, while the concentrated solution passing through the flow rate adjusting valve 12 flows into the rectifier 3 below the heat exchanger 10. is there.

This heat exchanger 10 is formed in a spiral shape in this example in order to increase the contact area with the refrigerant vapor,
The inflow port is connected to the evaporator 9, and the outflow port is connected to the absorber 7.

Since the low-pressure refrigerant flowing through the heat exchanger 10 has a low temperature and cools the refrigerant vapor rising outside the heat exchanger 10, the refrigerant vapor is cooled and at the same time, the refrigerant concentration is balanced. Concentrates low (or, conversely, high absorbent) solutions, increasing purity.

Then, the highly purified refrigerant vapor flows out from the upper portion of the rectifier 3 to the condenser 3.

The high-purity refrigerant vapor flowing out from the upper part of the rectifying device 3 discards heat to the outside in the condenser 6 and is liquefied, and is decompressed by the expansion valve 8 to become a low temperature and enters the evaporator 9 from the outside. It receives heat, evaporates, and returns to the absorber 7.

On the other hand, the liquid condensed from the refrigerant vapor flows down through the packed bed 5 to exchange heat and substance with the ascending vapor, and when it flows down to the central portion of the heat exchanger 10, the flowing concentrated solution flows. At the same time, heat and substance exchange are performed with the refrigerant vapor flowing down in the packed bed 5 and rising.

These liquids are mixed with the liquid flowing in from the refrigerant vapor generator 4 in the lower part of the rectifier 3 while reducing the concentration while generating vapors of equilibrium concentration, and become solution heat. It flows out to the exchanger 2, where the dilute solution gives its sensible heat to the concentrated solution to lower the temperature, and then returns to the absorber 7 via the pressure reducing valve 11.

As described above, the refrigerant vapor rising inside the rectifier 3 flows without being absorbed in a large amount by the flowing solution.

In the absorber 7, the refrigerant vapor is absorbed in the dilute solution,
The absorption heat generated at that time is discarded to the outside.

When the absorption type heat pump device is used for cooling or freezing, the cold heat of the evaporator 9 is used, and when it is used for heating or hot water supply, the hot heat of the condenser 6 and the absorber 7 is used.

In the absorber 7, the heat recovered by the heat exchanger can also be used.

As described above, since the high-purity refrigerant vapor can be obtained without decreasing, the capacity and efficiency of the absorption heat pump device are further enhanced.

In each of the first to third embodiments described above, the packed bed 5 is filled to secure the contact area in the rectifier 3, but the present invention is not limited to this. It is possible to easily adapt to a rectifier adopting.

Although the shape of the heat exchanger 10 has been described as a spiral shape, the shape is not particularly limited to this example as long as it can separate the refrigerant vapor and the solution for heat exchange from each other.

[0095]

EFFECTS OF THE INVENTION The absorption heat pump device according to the present invention has a structure in which a heat exchanger for performing only heat exchange without directly contacting the branched concentrated solution and the refrigerant vapor is installed on the upper part of the rectifier. And high efficiency.

Particularly, in the device according to the first aspect of the invention, the heat of the refrigerant vapor is recovered by the branch concentrated solution by heat exchange between the refrigerant vapor and the branched concentrated solution, so that the efficiency is high and
It has the advantage of a simple configuration.

Further, in the device according to the third aspect of the present invention, the refrigerant from the evaporator having the lowest temperature in the pump system is caused to flow into the heat exchanger, so that the contact area of the heat exchanger with the branched concentrated solution is increased. Even if is small, sufficient heat exchange can be performed.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an absorption heat pump device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of an absorption heat pump device according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of an absorption heat pump device according to a third embodiment of the present invention.

FIG. 4 is a configuration diagram of a conventional absorption heat pump device.

FIG. 5 is an explanatory diagram of gas-liquid equilibrium inside the rectifier.

[Explanation of symbols]

1 ... solution pump, 2 ... solution heat exchanger, 3 ... rectifier, 5 ...
Packed bed, 6 ... Condenser, 7 ... Absorber, 8 ... Expansion valve, 9 ... Evaporator, 10 ... Heat exchanger, 12 ... Flow control valve.

Claims (5)

[Claims] 1. At least an absorber, a refrigerant vapor generator, a condenser, an evaporator, and a rectifier, which guide a part of the concentrated solution having a high refrigerant concentration obtained from the absorber to the rectifier. In an absorption heat pump that increases the purity of the refrigerant vapor by exchanging heat and substance with the refrigerant vapor rising from the bottom of the rectifier, in the upper part of the rectifier, without directly contacting the concentrated solution and the refrigerant vapor. Install a heat exchanger that only performs heat exchange,
An absorption heat pump device characterized in that a concentrated solution is caused to flow into a rectifier after heat exchange with refrigerant vapor. 2. The absorption heat pump device according to claim 1, wherein the temperature of the concentrated solution at the outlet of the heat exchanger is set near the boiling point of the concentrated solution at the pressure of the rectifier. 3. At least an absorber, a refrigerant vapor generator, a condenser, an evaporator, and a rectifying device are provided, and a part of the concentrated solution having a high refrigerant concentration obtained from the absorber is guided to the rectifying device. In an absorption heat pump that increases the purity of the refrigerant vapor by exchanging heat and substance with the refrigerant vapor rising from the bottom of the rectifier, in the upper part of the rectifier, heat that performs heat exchange between cooling water and the refrigerant vapor. An absorption type heat pump device, characterized in that an exchanger is installed, and the concentrated solution is caused to flow into the rectifier from a position below the heat exchanger. 4. At least an absorber, a refrigerant vapor generator, a condenser, an evaporator, and a rectifier are provided, and a part of the concentrated solution having a high refrigerant concentration obtained from the absorber is guided to the rectifier. In an absorption heat pump that raises the purity of the refrigerant vapor by exchanging heat and substance with the refrigerant vapor rising from the bottom of the rectifier, in the upper part of the rectifier, between the refrigerant vapor flowing out of the evaporator and the refrigerant vapor An absorption heat pump device, wherein a heat exchanger for exchanging heat is installed, and the concentrated solution is caused to flow into the rectifier from a position below the heat exchanger. 5. A flow rate adjusting valve for increasing the flow rate of the concentrated solution when the temperature of the refrigerant vapor discharged from the upper part of the rectifier is high, and the flow rate adjusting valve is provided. The absorption heat pump device as described in.