JPH05264117A - Chemical heat pump - Google Patents

Abstract

PURPOSE:To effectively utilize heat of vaporization of liquefied natural gas. CONSTITUTION:A pair of reactors 6, 7 filled with ammonia complex of calcium chloride, in which ammonia gas is released when its pressure is high and absorbed when its pressure is low and heat is generated when the ammonia gas is absorbed. A condenser 22, wherein ammonia gas is condensed by cooled heat medium 34, is connected to one of the reactors 6 and an evaporator 26, wherein liquid ammonia is vaporized by means of sea water 25, is connected to the outlet side of liquid ammonia of the condenser 22, while the other reactor 7 is connected to the outlet side of the evaporator 26.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a chemical heat pump.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 4, at an LNG base, liquefied natural gas 2 stored in an LNG tank 1 is guided to an evaporator 3 so that the evaporator 3 exchanges heat with seawater 4. The natural gas 5 vaporized by heat exchange was supplied to the destination.

[0003]

However, the above-mentioned LNG base has a problem that a large amount of cold heat including the heat of vaporization of the liquefied natural gas 2 is dumped into the sea.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a chemical heat pump capable of effectively utilizing the heat of vaporization of liquefied natural gas.

[0005]

DISCLOSURE OF THE INVENTION According to the present invention, calcium chloride that releases ammonia gas when the pressure of the ammonia gas is low, absorbs the ammonia gas when the pressure of the ammonia gas is high, and generates heat when the ammonia gas is absorbed. A pair of reactors 6 and 7 filled with the ammonia complex is provided, and one of the reactors 6 is connected to a condenser 22 for condensing the ammonia gas by the cooled heat medium 34, and the liquid ammonia outlet side of the condenser 22. An evaporator 26 for evaporating liquid ammonia with seawater 25 is connected to the evaporator 26.
The present invention relates to a chemical heat pump characterized in that the other reactor 7 is connected to the outlet side of.

[0006]

According to the present invention, an ammonia complex of calcium chloride that releases ammonia gas when the pressure of the ammonia gas is low, absorbs the ammonia gas when the pressure of the ammonia gas is high, and generates heat when the ammonia gas is absorbed is formed. A pair of filled reactors 6 and 7 is provided, and a condenser 22 is connected to one reactor 6.

Then, the ammonia gas in the reactor 6 flows into the condenser 22, and in this state, the cooled heat medium 34
Is supplied to the condenser 22 to condense the ammonia gas in the condenser 22, the pressure of the ammonia gas in the condenser 22 is reduced, and the pressure of the ammonia gas in the reactor 6 is also reduced. The ammonia complex of calcium releases ammonia gas, and the ammonia gas generated in the reactor 6 flows to the condenser 22 having a low pressure.
The condensation of ammonia gas in 2 proceeds.

The liquid ammonia produced by condensation in the condenser 22 is then sent to the evaporator 26 and the evaporator 2
At 6, the water is evaporated by the seawater 25 to become ammonia gas.

When the ammonia gas is generated in the evaporator 26, the pressure of the ammonia gas in the evaporator 26 rises, the pressure of the ammonia gas in the other reactor 7 also rises, and the chloride in the other reactor 7 The ammonia complex of calcium absorbs ammonia gas and generates heat.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show an embodiment of the present invention.

[0012] inside, the pressure of the ammonia gas is ammonia gas released when low, as the pressure of the ammonia gas absorbs ammonia gas when high thermal ammonia complex of calcium chloride for generating (CaCl ₂ · when ammonia gas absorption A pair of reactors 6 and 7 filled with nNH ₃ ; n = 4 or 8) is provided.

For example, as shown in FIGS. 2 and 3, the reactors 6 and 7 (solid-phase reactors) are partitioned at both ends by a pair of tube plates 8 to form a gas chamber 9 at the center and at both ends. Heat medium chamber 10
And a heat transfer medium pipe 12 with fins that passes through the gas chamber 9 of the reactor main body 11 and communicates with both heat transfer medium chambers 10, and surrounds the outer periphery of the heat transfer medium pipe 12. It is constituted by a porous tube (or a porous film) 14 that forms a large number of cells 13 with the heat medium tube 12, and one heat medium chamber 10 is partitioned by a partition plate 15 to form headers 16 and 17. ,
Heat medium supply pipe 1 for supplying and discharging a heat medium 18 such as seawater or water
9 and the heat medium discharge pipe 20 are connected.

Then, via the ammonia gas flow path 21 into the gas chamber 9 of the one reactor 6, the ammonia gas is heated by the heat medium 34 such as naphtha, gasoline or propane cooled by the liquefied natural gas 2 in the heat exchanger 35. Is connected to the inlet side of a condenser 22 for condensing, and the condenser 22 is connected to an inlet side of an evaporator 26 for evaporating liquid ammonia by seawater via a liquid ammonia flow path 24 equipped with an ammonia pump 23, The gas chamber 9 of the other reactor 7 is connected to the outlet side of the evaporator 26 via an ammonia gas flow path 27.

Then, both ammonia gas flow paths 21 and 27
Bypass channels 28 and 29 are connected between them.

In the figure, reference numerals 30, 31, 32 and 33 are valves.

Next, the operation will be described.

[0018] First, the reactor ammonia complex of calcium chloride in 6 is CaCl ₂ · 8NH _3, ammonia complex of calcium chloride in the reactor 7 is CaCl ₂ · 4NH ₃
If so, first open the valves 30 and 31 and open the valve 3
Close 2, 33.

Then, the heat medium 18 such as seawater or water is caused to flow through the heat medium supply pipe 19 of the reactor 6 and discharged from the heat medium discharge pipe 20. In the reactor 6, the ammonia complex of calcium chloride and the ammonia gas are kept in equilibrium, but when the valve 30 is opened, the gas chamber 9 of the reactor 6 and the condenser 22 are connected by the ammonia gas flow passage 21. As a result, the ammonia gas in the reactor 6 flows into the condenser 22 and the pressure of the ammonia gas in the reactor 6 drops, so that the equilibrium state in the reactor 6 collapses.

Then, in order to maintain the above equilibrium state, the following reaction proceeds in the reactor 6, ammonia gas is released from the ammonia complex of calcium chloride, and the pressure of the ammonia gas in the reactor 6 and the condenser 22 is increased. The reaction continues until equalized.

CaCl ₂ · 8NH ₃ → CaCl ₂ · 4NH ₃ + 4NH ₃

In this state, the heat medium 34 cooled in the heat exchanger 35 by the liquefied natural gas 2 and having a temperature of approximately minus 70 degrees.
Is sent to the condenser 22, the ammonia gas in the condenser 22 is condensed by the cold heat of the heat medium 34, and liquid ammonia is generated in the condenser 22.

When the ammonia gas is condensed inside the condenser 22, the pressure of the ammonia gas inside the condenser 22 is lowered to about 0.1 to 0.2 atm, and the ammonia gas is connected to the condenser 22 through the ammonia gas flow passage 21. Since the ammonia gas in the gas chamber 9 of the reactor 6 thus sucked is sucked toward the condenser 22 side, the pressure of the ammonia gas inside the reactor 6 decreases,
Since the equilibrium state between the ammonia complex of calcium chloride and the ammonia gas in the reactor 6 is destroyed again, the reaction proceeds in the reactor 6 in an attempt to maintain the equilibrium state as described above.
Release of ammonia gas occurs continuously.

As a result, a flow of the ammonia gas from the reactor 6 to the condenser 22 is generated, and the ammonia gas flow advances the condensation of the ammonia gas in the condenser 22 as described above.

The above operation is performed until the ammonia complex of calcium chloride in the reactor 6 becomes almost CaCl ₂ .4NH ₃ .

At this time, the liquefied natural gas 2 supplied to the heat exchanger 35 also indirectly obtains the condensation heat of the ammonia gas from the heat medium 34 and is vaporized to become the natural gas 5, so that it is directly supplied to the destination. be able to.

The liquid ammonia stored by the condensation of the ammonia gas inside the condenser 22 passes through the liquid ammonia flow path 24 by the ammonia pump 23, and then the evaporator 2
6 and is vaporized in the evaporator 26 by seawater of approximately 20 degrees.

When the liquid ammonia is evaporated in the evaporator 26, the pressure of the ammonia gas inside the evaporator 26 is 6 to 7a.
Since the pressure is as high as about tm, the other reactor 7 having a lower pressure is passed through the ammonia gas flow path 27 by the pressure.
A flow of ammonia gas towards is produced.

Then, in the reactor 7, the pressure of the internal ammonia gas rises and the equilibrium state between the ammonia complex of calcium chloride and the ammonia gas is broken, so that the following reactions are performed in the reactor 7 in order to maintain the equilibrium state. Then, the ammonia gas is continuously absorbed.

The _{CaCl 2 · 4NH 3 + 4NH 3} → CaCl 2 · 8NH 3

Since the reaction is an exothermic reaction, by supplying the heat medium 18 such as water to the reactor 7, the heat medium 18 is heated and heat (warm water) of about 50 to 60 degrees can be recovered. ..

The hot water is used, for example, to prevent freezing of the LNG tank and for heating.

When the ammonia complex of calcium chloride in the reactor 6 almost exhausts the ammonia gas and the ammonia complex of calcium chloride in the reactor 7 almost absorbs the ammonia gas, the valves 30 and 31 are closed. Then, the valves 32 and 33 are opened, the heat medium supply pipe 19 of the reactor 7 is caused to flow the heat medium 18 such as seawater or water, and the heat medium discharge pipe 20 discharges the heat medium 18. The operation can be continued by releasing the ammonia gas from 7 and causing the reactor 6 to absorb the ammonia gas.

In the present invention, the cold heat of the liquefied natural gas can be recovered as warm heat with a very simple structure.

The present invention is not limited to the above-mentioned embodiments, and the reactors 6 and 7 can be switched at regular intervals by providing a timer. It is needless to say that the internal pressures of 6 and 7 may be detected, and other various changes may be made without departing from the scope of the present invention.

[0036]

As described above, according to the chemical heat pump of the present invention, it is possible to effectively use the heat of vaporization of liquefied natural gas.

[Brief description of drawings]

FIG. 1 is a schematic system diagram of an embodiment of the present invention.

FIG. 2 is an enlarged view of the reactor of FIG.

FIG. 3 is an enlarged view of the heat transfer medium pipe of FIG.

FIG. 4 is a schematic system diagram of a conventional LNG base.

[Explanation of symbols]

 6,7 Reactor 22 Condenser 25 Seawater 26 Evaporator 34 Heat medium

Claims (1)

[Claims] 1. A pair of calcium-complex-containing ammonia complexes that release ammonia gas when the pressure of the ammonia gas is low, absorb the ammonia gas when the pressure of the ammonia gas is high, and generate heat when the ammonia gas is absorbed. The reactors 6 and 7 are provided, the condenser 22 for condensing ammonia gas by the cooled heat medium 34 is connected to one of the reactors 6, and liquid ammonia is evaporated on the liquid ammonia outlet side of the condenser 22 by seawater 25. The chemical heat pump is characterized in that an evaporator 26 to be connected is connected, and the other reactor 7 is connected to the outlet side of the evaporator 26.