JPH0379625B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in absorption heat pumps. In general, absorption heat pumps maintain the inside of the vessel at 1 atmosphere or less and extract heated fluids such as hot water, and are not covered by the so-called high-pressure vessels under the law, so they are widely used as highly safe equipment. It is something that

When comparing dual-effect absorption heat pumps and single-effect absorption heat pumps, the former can raise the temperature of the heated fluid more efficiently than the latter, but the temperature of the heat source fluid supplied to the evaporator must be set higher. There is a restriction that it must be done. Because,
As the temperature of the heat source fluid supplied to the evaporator decreases, the internal pressure of the evaporator decreases, so in order to maintain the refrigerant absorption effect in the absorber, the concentration of the absorption liquid sprayed in the absorber must be increased. It is necessary to maintain the saturated vapor pressure of the absorption liquid lower than the internal pressure of the evaporator, and therefore the amount of heating to the regenerator must be increased to increase the concentration rate of the absorption liquid. This is because the former is operated at a pressure several times higher than the pressure inside the regenerator in the latter, and by increasing the amount of heating, the regenerator internal pressure in the former reaches 1 atmosphere or more faster than in the latter.

In view of these circumstances, the present invention provides dual-effect absorption heat pump operation, single-effect absorption heat pump operation, or operation of a high-temperature regenerator depending on the temperature of the heat source fluid supplied to the evaporator. The purpose of this system is to stably raise the temperature of the heated fluid while maintaining the internal pressure at 1 atm or less by adopting a configuration in which the heating fluid is switched to one of the so-called boiler operations that raise the temperature of the heated fluid.

Embodiments of the present invention will be described below with reference to the drawings. In Figure 1, 1 is a combustion heating chamber 2 for kerosene, etc.
3 is a high-temperature regenerator that generates refrigerant vapor from a dilute liquid and concentrates it into an intermediate liquid, and 3 is a low-temperature regenerator that uses the heat of the refrigerant vapor from the high-temperature regenerator 1 to further generate refrigerant vapor from the intermediate liquid to convert it into a concentrated liquid. 4 is a condenser that condenses and cools the refrigerant vapor from both regenerators 1 and 3; 5 is an evaporator that vaporizes the refrigerant liquid from the condenser 4; 6 is an evaporator that converts the vaporized refrigerant from the evaporator 5 into an absorption liquid. Absorbers 7 and 8 are hot and cold solution heat exchangers, which include a refrigerant vapor pipe 9, a refrigerant liquid downflow pipe 10,
A refrigerant circulation path 12 having a refrigerant pump 11, a dilute liquid pipe 14 having a solution pump 13, an intermediate liquid pipe 15, and a concentrated liquid pipe 16 are connected to form a dual-effect absorption heat pump system.

Reference numeral 17 denotes an auxiliary condenser, and the upper part of the auxiliary condenser is connected to a branch pipe 18 of the refrigerant vapor pipe 9, and the lower part thereof is connected to a refrigerant liquid return pipe 19 that returns the refrigerant drain to the high-temperature regenerator 1 and the condenser 4. A refrigerant drain pipe 20 for guiding a refrigerant drain is connected thereto. And 21
and 22 are valves arranged in the refrigerant liquid return pipe 19 and the refrigerant drain pipe 20, respectively.

23 is a heat source tube housed in the evaporator 5; 24 is a heated fluid extraction tube housed sequentially in the absorber 6, condenser 4, and auxiliary condenser 17; 25 is a fuel supply tube to the combustion heating chamber 2; There is a valve 2 in the fuel supply pipe.
6 is arranged, and an evaporator 5 inlet side heat source tube 23 for the heat source fluid and an auxiliary condenser 17 for the heated fluid are provided.
The outlet-side heated fluid extraction pipe 24 is equipped with temperature detectors 27 and 28, respectively. 29 is a refrigerant blow pipe with a valve 30 that connects the refrigerant circulation path 12 and the absorber 6.

31 is a valve 26 in response to a signal from a temperature sensor 28.
32 is a control for switching the opening/closing of the valves 21, 22, and 30 and/or increasing/decreasing the opening degree of the valves 21, 22, and 30 according to the signal from the temperature detector 27, and also adjusting the rate of increase/decrease in the opening degree of the valve 26. It is a vessel.

Next, the control operation of the embodiment of the present invention will be explained. When the temperature of the heat source fluid supplied to the evaporator 5 is equal to or higher than the first lower limit set temperature, the valves 21, 22, and 30 are
is fully closed, and the heated fluid is taken out from the dual-effect absorption heat pump system described above. In other words, heat radiation from the absorber 6 and condenser 4 raises the temperature of the heated fluid.

When the temperature of the heat source fluid supplied to the evaporator 5 decreases to below the first lower limit set temperature and equal to or higher than the second lower limit set temperature, the valves 21 and 30 are fully closed via the controller 32 in response to a signal from the temperature detector 27. Open the leave valve 22. When the valve 22 is opened, more of the refrigerant vapor generated in the high temperature regenerator 1 flows to the branch pipe 18 side than to the refrigerant vapor pipe 9 side via the low temperature regenerator 3, which has a large flow resistance, and reaches the auxiliary condenser 17. It exchanges heat with the heated fluid in the auxiliary condenser and becomes a refrigerant drain.
This refrigerant drain passes through the drain pipe 20 to the condenser 4.
It is then cooled and supplied to the evaporator 5. That is, the fluid to be heated is taken out from a single-effect absorption heat pump system in which the temperature is raised by heat radiation from the absorber 6 and the auxiliary condenser 17.

When the temperature of the heat source fluid supplied to the evaporator 5 falls below the second lower limit set temperature, the valve 22 is closed via the controller 32 in response to a signal from the temperature detector 27.
1 and 30 and by opening the valve 21, much of the refrigerant separated in the high temperature regenerator 1 is circulated between the high temperature regenerator and the auxiliary condenser 17, forming a cycle. That is, the fluid to be heated is transferred to the auxiliary condenser 17.
It is extracted from the boiler system, where the temperature rises due to the heat of condensation of the refrigerant vapor. Also, by opening the valve 30, the unevaporated refrigerant liquid in the evaporator 5 is transferred to the absorber 6.
It is possible to dilute the concentration of the absorption liquid flowing back to the high-temperature regenerator 1 and lower the boiling temperature of the absorption liquid in the regenerator, thereby saving energy for heating the absorption liquid. Pressure can also be kept low. In addition, the valves 21 and 22 are not only opened and closed according to the signal from the temperature detector 27, but also the degree of opening is increased or decreased according to the temperature of the heat source fluid, or in other words, according to the vaporization capacity of the evaporator 5. It may be controlled as follows.

In other words, the temperature controller 31 is controlled by a signal from the temperature detector 28 depending on the temperature at the outlet side of the auxiliary condenser 17 of the fluid to be heated.
The opening degree of the valve 26 is increased or decreased through the high temperature regenerator 1.
Adjust the amount of heating to increase or decrease.

In addition, in each case where the heated fluid is extracted from a dual-effect absorption heat pump system, a single-effect absorption heat pump system, or a boiler system, the so-called result is the heat output extracted from the heated fluid with respect to the heating input to the high-temperature regenerator 1. Since the coefficients are different, valve 26
The opening increase/decrease rate is adjusted as shown in FIG. 2, for example. That is, temperature detection is performed when the supply temperature of the heat source fluid is equal to or higher than the first lower limit set temperature, lower than the first lower limit set temperature and higher than the second lower limit set temperature, or lower than the second lower limit set temperature. Based on the signal from the controller 27, the opening increase/decrease rate of the valve 26 relative to the load is set to 0.5, 0.6 or 0.6, respectively, via the controller 32.
Adjusted to 1.0. By adjusting in this way, an over input of the amount of heating to the high temperature regenerator 1 is prevented, and it is also useful to maintain the internal pressure of the regenerator at 1 atmosphere or less.

As described above, in the present invention, when the temperature of the heat source fluid supplied to the evaporator is sufficiently high and equal to or higher than the first lower limit set temperature, the heat source is heated from an efficient (high coefficient of performance) dual-effect absorption heat pump system. When the fluid is taken out and the temperature of the heat source fluid is lower than the first lower limit set temperature and higher than the second lower limit set temperature, the concentration of the absorbent supplied to the absorber is increased to 2 while maintaining the internal pressure of the high temperature regenerator at 1 atm or less. The fluid to be heated is taken out from the single-effect absorption heat pump system, which can have a higher concentration of the absorption liquid supplied to the absorber in the double-effect absorption heat pump system, and the heat source fluid temperature further decreases to the second lower limit set temperature. Since the heated fluid is taken out from the boiler system when the temperature drops below 1 atm, the temperature of the heated fluid can be stably raised while maintaining the inside of each component (especially the high-temperature regenerator) at 1 atm or less. It is something.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of the circuit configuration of an embodiment of the present invention;
Figure 2 is a diagram illustrating the opening degree (%) of the fuel valve corresponding to the load (%). The valve opening degree with respect to the load is shown when the temperature is above the temperature, when the temperature is below the first lower limit set temperature and above the second lower limit set temperature, and when the load is below the second lower limit set temperature. 1...High temperature regenerator, 3...Low temperature regenerator, 4...
Condenser, 5... Evaporator, 6... Absorber, 7, 8...
... Solution heat exchanger, 9 ... Refrigerant vapor pipe, 17 ... Auxiliary condenser, 18 ... Branch pipe, 19 ... Refrigerant liquid return pipe, 20 ... Refrigerant drain pipe, 21, 22 ... Valve,
27...Temperature detector, 32...Controller.

Claims (1)

[Claims] 1 High temperature regenerator, low temperature regenerator, condenser, evaporator,
A dual-effect heat pump system that connects an absorber and a solution heat exchanger to form an absorption heat pump cycle to raise the temperature of a heated fluid, a high-temperature regenerator, an auxiliary condenser attached to the regenerator, an evaporator, A single-effect heat pump system that connects an absorber and a solution heat exchanger with piping to form an absorption heat pump cycle to raise the temperature of the heated fluid, and a refrigerant circulation cycle that connects a high-temperature regenerator and an auxiliary condenser with piping. The refrigerant liquid return pipe from the auxiliary condenser to the high-temperature regenerator and the refrigerant drain pipe from the auxiliary condenser to the condenser are provided with valves. The opening and closing of the valve is controlled by a signal from a detection mechanism that detects the temperature of the heat source fluid supplied to the evaporator, and when the temperature of the heat source fluid is equal to or higher than the first lower limit temperature, the heated fluid is raised by a dual-effect heat pump system. When the temperature of the heat source fluid is lower than the first lower limit temperature and higher than the second lower limit temperature, the heated fluid is heated by a single-effect heat pump system, and when the temperature of the heat source fluid is lower than the second lower limit temperature, the heated fluid is heated. An absorption heat pump characterized by being equipped with a controller that raises the temperature in a boiler system.