JPH041267B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a LiBr-water based two-stage absorption type chilled/hot water device for producing hot water and cold water for use in heating, cooling, etc. A problem with conventional LiBr-water absorption chiller/heater systems is that high efficiency cannot be achieved because the heat pump cannot be operated during heating. First, the operation of the conventional example shown in FIG. 1 will be explained. Figure 1a shows a heating cycle. In this cycle, high-temperature steam generated in the first generator a enters the evaporator d via the second generator b, condenser c, etc. The hot water flowing through the vessel d is heated and condensed, and is absorbed by the concentrated solution in the absorber e to become a dilute solution and sent to the first generator a again, and the hot water is used for heating. Ru. On the other hand, the concentrated solution separated from the water vapor in the first generator a is sent directly into the absorber e via a path g having an air conditioning switching valve f which is open. In this way, the heating cycle does not involve heat pump operation and is no different from boiler operation, so it is best to maintain an efficiency of, for example, 80%. Next, FIG. 1b shows a cooling cycle, in which the dilute solution is separated into high-temperature steam and intermediate solution by heating in the first generator a. First, high-temperature steam enters the second generator b and condenses.
It becomes a liquid refrigerant and flows into the condenser c. Also the second
The water vapor generated in generator b is also separated from the concentrated solution and condensed in condenser c to become a liquid refrigerant. These liquid refrigerants enter the evaporator d and evaporate under the vacuum created by the absorber e, removing heat from the cold water flowing in the evaporator d, and the cooled water is used for air conditioning. do. On the other hand, the intermediate solution separated from the water vapor in the first generator a is heat-exchanged with the dilute solution in the first heat exchanger i provided on the path h from the absorber e to the first generator a. It flows into the second generator b, where it is heated and concentrated by the high temperature steam to become a concentrated solution, and after exchanging heat with the dilute solution in the second heat exchanger j, it flows into the absorber e. The concentrated solution absorbs low-temperature water vapor and becomes a dilute solution, which is then transferred to the first and second heat exchangers i, j by the solution circulation pump k.
and returns to the first generator a. Also, the heat generated when the concentrated solution absorbs water vapor is removed by the cooling water passing through the cooling water path 1. The present invention solves the above conventional problems by providing two sets of evaporators and absorbers and rationally combining them to form a heating system and a cooling system. The purpose of this system is to improve efficiency by operating a heat pump in the air conditioner, and also to improve efficiency by increasing the heat transfer area of the evaporator and absorber during cooling. . The present invention will be described in detail below. FIGS. 2a and 2b show an embodiment of the cold/hot water apparatus of the present invention. ,
That is, the first evaporator 4, the first absorber 5, the second evaporator 4', the second absorber 5' and the solution heat exchanger, that is, the first, second and third solution heat exchangers 6, 6', The condenser 3 is connected to each evaporator 4, 4', and the dilute solution in the first absorber 5 is transferred to the second absorber 5', and the second absorber 5 is connected to the condenser 3. ' is configured to send the dilute solution of The second solution heat exchanger 6' is configured to exchange heat between the solutions in the path from the second generator 2 to the first absorber 5, and
The structure is such that heat is exchanged between the solutions in the path from the first absorber 5 to the third solution heat exchanger 6'', and the third solution heat exchanger 6'' exchanges heat from the second absorber 5' to the first solution heat exchanger. The structure is such that heat is exchanged between the solution in the path leading to the vessel 6 and the path leading from the second solution heat exchanger 6' to the second absorber 5'. In the above configuration, the present invention provides a hot water supply path A that runs from the hot water inlet 7 to the hot water outlet 7' via the second absorber 5' and the condenser 3;
a cold water circulation path B that circulates between the first evaporator 4 and the outside air heat exchange section 16;
A heating system is constituted by a hot water circulation path C circulating between the evaporators 4', and a cold water supply path leading from the cold water inlet 8 through the second evaporator 4' and the first evaporator 4 to the cold water outlet 8'. D, and a cooling water path E extending from the cooling water inlet 9 through the second absorber 5', the first absorber 5, and the condenser 3 to the cooling water outlet 9', A switching mechanism is configured to switch between a heating system and a cooling system. In the illustrated example, the switching mechanism includes four switching valves 10, 1.
0', 10'', 10 and a route passing through these, but these may be configured as appropriate.The operation of the present invention in the above configuration will be explained as follows.First, During heating, the switching mechanism is operated to configure the heating system as shown in Figure 2a.When the first generator 1 is heated, the dilute solution is separated into high temperature steam and intermediate solution. The temperature of the intermediate solution decreases through the first solution heat exchanger 6,
to the second generator 2. On the other hand, the high-temperature water vapor that has reached the second generator 2 from the first generator 1 is condensed and becomes a liquid refrigerant that flows into the condenser 3, and the water vapor generated in the second generator 2 also flows into the condenser 3. It condenses to become a liquid refrigerant. Heat is then applied to the hot water in the hot water supply path A in the condenser 3. The liquid refrigerant then reaches the first evaporator 4 and the second evaporator 4' and evaporates, becoming low-temperature water vapor. At this time, cold water that has undergone heat exchange with outside air is being circulated through the first evaporator 4 through the cold water circulation path B, giving heat to low-temperature steam whose temperature is lower than that of the cold water. On the other hand, the concentrated solution separated from the water vapor in the second generator 2 passes through the second solution heat exchanger 6' and reaches the first absorber 5 with its temperature reduced.
Here, the concentrated solution absorbs the aforementioned low temperature water vapor. The heat generated at this time is absorbed by the hot water in the hot water circulation path C, and the hot water in the hot water circulation path C is circulated to the second evaporator 4' to provide heat to the low temperature water vapor. On the other hand, the concentrated solution (second dilute solution) that has absorbed appropriate water vapor in the first absorber 5 passes through the second solution heat exchanger 6', and its temperature rises, and then passes through the third solution heat exchanger 6''. The temperature then decreases and reaches the second absorber 5', where it absorbs water vapor and becomes a dilute solution (first dilute solution), which is then transferred to the third and first solution heat exchangers 6'',
6, the temperature rises and the gas flows back to the first generator 1. Heat generated when the second dilute solution absorbs water vapor in the second absorber 5' is absorbed by the hot water in the hot water supply path A. The hot water that entered from the hot water inlet 7 as described above is
The temperature of the water is raised through the second absorber 5' and the condenser 3, and reaches the hot water outlet 7', where it can be used for heating. As is clear from the above description, during heating, the present invention sucks up the heat of Qe ₁ from the outside air through the cold water through the cold water circulation path B in the first evaporator 4, and then transfers the heat to the first absorber 4. In step 5, the heat of the hot water Qa ₁ in the hot water circulation path C is given, and the heat is sucked up as heat Qe ₂ in the second evaporator 4', and in the second absorber 5', Since the hot water in the hot water supply route A used for heating is given as heat Qa ₂ , that is, the heat pump is operated, high efficiency can be achieved. During such heat pump operation, the temperature of the hot water in the hot water circulation path C is determined by the heat entering the hot water Q _a1 and the heat exiting.
If Q _e2 is balanced, it can be kept constant, and this can be easily achieved by adding, for example, the following configuration in addition to the above configuration. That is, in this configuration, the hot water supply path A
A hot water path 12 controlled by a hot water control three-way valve 11 is provided downstream of the second absorber 5' in the hot water circulation path C. A first hot water heat exchanger 13 for exchanging heat with the side is provided, and refrigerant control is provided between the condenser 3 and the first and second evaporators 4, 4' to adjust the distribution ratio of liquid refrigerant to each. This configuration includes a three-way valve 14. In normal operation, the distribution ratio is, for example, 1:1 parallel flow. In this configuration, if Q _e2 >Q _a1 , the temperature of the circulating hot water decreases, so the following two control methods can be considered in the above configuration. As a first method,
The route 1 is controlled by the hot water control three-way valve 11.
Heat balance can be maintained by appropriately flowing hot water through the first hot water heat exchanger 13 and applying heat to the circulating hot water. Next, as a second method,
Heat balance can be maintained by controlling the refrigerant control three-way valve 14 to increase the distribution of liquid refrigerant to the first evaporator 4. Incidentally, the first hot water heat exchanger 13 is used to raise the temperature of the circulating hot water at the time of starting. In addition, when Q _e2 <Q _a1 , the temperature of the circulating hot water increases, so the heat balance can be maintained by controlling the refrigerant control three-way valve 14 to distribute more liquid refrigerant to the second evaporator 4'. can. By setting Q _e2 =Q _a1 in this way, the efficiency of the heat pump in the present invention becomes η _o =(Qa2 + Q _c )/Qg1. However, Qc and Qg1 are condenser 3 and 1st, respectively.
This is the heat of the generator 1. Furthermore, in the above operation, as the outside temperature rises, the pressure inside the first evaporator 4 increases, so if the circulating hot water is kept constant as described above, in order to keep the solution concentration unchanged, The temperature of the first absorber 5 may be increased. This is achieved by providing, in addition to the above configuration, a second hot water heat exchanger 13' in the hot water circulation path C that exchanges heat between the upstream and downstream sides of the second evaporator 4'. be able to. Furthermore, in order to be able to perform heating while preventing the cold water in the cold water circulation path B from freezing when the outside temperature drops significantly, the first generator 1 transmits air through the heating switching solenoid valve 15. A steam path 15' leading directly to the condenser 3 can be provided. In the above case, the heating switching solenoid valve 15 is opened and the high-temperature steam generated in the first generator 1 is directly introduced into the condenser 3 and condensed, thereby converting the hot water in the hot water supply path A into hot water. Heat can be applied to obtain hot water at the desired temperature. FIG. 3a shows a Duering diagram during heating according to the present invention as described above. In this diagram, for example, the temperature of the cold water in the cold water circulation path B is about 2.
When absorbing heat at °C, the desired temperature in one stage, approximately 55
It can be seen that if you try to obtain hot water at ℃, it will collide with the crystal line and crystallize. However, as described above, in the present invention, the temperature is raised in two stages via the hot water in the hot water circulation path C, so for example, by setting the temperature of the hot water in the hot water circulation path C to about 29°C, crystallization can be carried out. can be prevented. Then the third
The first, second, and third solution heat exchangers 6, 6', 6'' will be explained using Figure a as follows. First, the first solution of the intermediate solution exiting the first generator 1 The state points at the inlet and outlet of the heat exchanger 6 are indicated by points 12 and 13, that is, the temperature of the intermediate solution decreases from point 12 to 13, and the temperature of the first dilute solution increases from point 15 to 16. Ru.
In the second solution heat exchanger 6', the temperature of the concentrated solution decreases from point 8 to 9, and the temperature of the second dilute solution decreases from point 4 to point 14.
The temperature is raised to In addition, since the temperature at point 5 is required in the second absorber 5', heat is exchanged with the first dilute solution in the third solution heat exchanger 6'', and the second dilute solution is heated at point 14→5.
The temperature of the first dilute solution increases from point 6 to point 15. Since the present invention is thus provided with the first, second, and third solution heat exchangers 6, 6', and 6'', the temperature difference between the first absorber 5 and the second absorber 5' can be Heat can be effectively recovered by the temperature difference between The cooling water in the water path E removes the heat generated in the first and second absorbers 5, 5' as well as the condenser 3 and passes through the first and second evaporators 4, 4'. Chilled water at a desired temperature can be obtained through the cold water supply path D and can be used for air conditioning.
Since a set of evaporator and absorber is used, there is plenty of heat transfer area between the evaporator and absorber, and the stepwise temperature drop allows for higher efficiency than before. In addition, during such cooling, cooling water is allowed to flow through the path where hot water was flowing during heating, and the cold water supply path D is connected to the external air conditioning load side in the same way as the hot water supply path A during heating. Such connection switching can be easily performed by an eight-way valve 17 as shown in the figure. FIG. 3b shows a Dueling diagram during cooling according to the present invention. Tables 1 and 2 show examples of the results of theoretical analysis of the operation of the present invention during heating and cooling, respectively. It is calculated that the COP is approximately 1.5, and the COP is approximately 1.5 during cooling, so it can be clearly understood that the system can be operated with extremely high efficiency.

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[Table] Dueling diagram number

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[Table] As described above, the present invention has two sets of evaporator and absorber.
The main feature is that the heat pump can be operated during heating by rationally combining them to form a heating system and a cooling system, which allows for a significant increase in thermal efficiency compared to conventional systems. . Also, during cooling, there is plenty of heat transfer area between the evaporator and absorber, and the temperature of the cold water is lowered in two stages, so the temperature of the second stage evaporator can be higher than the first stage evaporator temperature. Therefore, by increasing the evaporator temperature, it is possible to obtain higher efficiency than before.

[Brief explanation of drawings]

Figures 1a and 1b are explanatory diagrams of conventional examples, and
FIGS. 3A and 3B are system explanatory diagrams for explaining the configuration and operation of the present invention, and FIGS. 3A and 3B are Dueling diagrams showing the operation of the present invention. Code 1, 2...First, second generator, 3...Condenser, 4,4'...First, second evaporator, 5,5'...
...First and second absorbers, 6, 6', 6''...First, second and third solution heat exchangers, 7...Hot water inlet, 7'...
...Hot water outlet, 8...Cold water inlet, 8'...Cold water outlet,
9...Cooling water inlet, 9'...Cooling water outlet, 10,
10', 10'', 10...Switching valve, 11...Hot water control three-way valve, 12...Hot water path, 13...First hot water heat exchanger, 14...Refrigerant control three-way valve, 15...
Heating switching solenoid valve, 15'...Water vapor path, 16...
...Outside air heat exchange section, 17...8-way valve, 18 circulation pump, A...Hot water supply route, B...Cold water circulation route,
C...Hot water circulation route, D...Cold water supply route, E...
...Cooling water path.

Claims (1)

[Claims] 1. First and second generators, condensers, evaporators,
Consists of absorber and solution heat exchanger
In a LiBr-water-based absorption chiller/heater, two sets of evaporators and absorbers are provided, each evaporator and the condenser are connected, and the dilute solution in the first absorber is transferred to the second absorber. , and a configuration in which the dilute solution of the second absorber is sent to the first generator, and a hot water supply path from the hot water inlet to the hot water outlet via the second absorber and the condenser, and the first evaporator and the outside air. A heating system is constituted by a cold water circulation path that circulates between the heat exchange parts of the heat exchanger, and a hot water circulation path that circulates between the first absorber and the second evaporator. A cooling system consists of a cold water supply path that passes through the first evaporator and reaches the chilled water outlet, and a cooling water path that runs from the cooling water inlet to the cooling water outlet via the second absorber, the first absorber, and the condenser. A LiBr-water system two-stage absorption chiller/heater, further comprising a switching mechanism for switching between the heating system and the cooling system. 2. The switching mechanism is characterized in that the cold water supply path and the hot water supply path can be selectively connected to the external air conditioning load side, and is also equipped with an eight-way valve for flowing cooling water into the cooling water path during cooling. A LiBr-water based two-stage absorption type chilled/hot water device according to claim 1. 3. In a LiBr-water absorption type chilled/hot water device whose components include a generator, condenser, evaporator, absorber, and solution heat exchanger, two sets of evaporator and absorber are provided, and each evaporator and the condenser, the dilute solution in the first absorber is sent to the second absorber, and the dilute solution in the second absorber is sent to the generator, and the hot water inlet is connected to the second absorber and condensed. a hot water supply path leading to the hot water outlet via the container; a cold water circulation path circulating between the first evaporator and the outside air heat exchange section;
Constructing a heating system consisting of a hot water circulation path circulating between the first absorber and the second evaporator,
A cold water supply path from the cold water inlet to the chilled water outlet via the second evaporator and the first evaporator, and cooling water from the chilled water inlet to the chilled water outlet via the second absorber, the first absorber, and the condenser. and a switching mechanism for switching between the heating system and the cooling system, and a hot water control three-way valve downstream of the second absorber in the hot water supply path. A hot water path controlled by the above method is provided, and a first hot water heat exchanger for exchanging heat with the downstream side of the first absorber in the hot water circulation path is provided in the path, and a first hot water heat exchanger that exchanges heat with the downstream side of the first absorber in the hot water circulation path is provided. A refrigerant control three-way valve is provided between the two evaporators to adjust the distribution ratio of liquid refrigerant to each evaporator, and a second evaporator for heat exchange between the upstream and downstream sides of the second evaporator is provided in the hot water circulation path. A LiBr-water system two-stage absorption type chilled/hot water device characterized by being equipped with a hot water heat exchanger. 4. The switching mechanism is characterized in that the cold water supply path and the hot water supply path can be selectively connected to the external air conditioning load side, and is provided with an eight-way valve for flowing cooling water into the cooling path during cooling. LiBr-water system two-stage absorption type chilled/hot water device according to claim 3. 5. In a LiBr-water absorption type chilled/hot water device whose components include a generator, condenser, evaporator, absorber, and solution heat exchanger, two sets of evaporator and absorber are provided, and each evaporator and the condenser, the dilute solution in the first absorber is sent to the second absorber, and the dilute solution in the second absorber is sent to the generator, and the hot water inlet is connected to the second absorber and condensed. a hot water supply path leading to the hot water outlet via the container; a cold water circulation path circulating between the first evaporator and the outside air heat exchange section;
Constructing a heating system consisting of a hot water circulation path circulating between the first absorber and the second evaporator,
A cold water supply path from the cold water inlet to the chilled water outlet via the second evaporator and the first evaporator, and a chilled water supply path from the chilled water inlet to the chilled water outlet via the second absorber, the first absorber, and the condenser. a cooling system comprising a heating system and a cooling system, further comprising a switching mechanism for switching between the heating system and the cooling system, and further comprising a water vapor path from the first generator directly to the condenser via the heating switching solenoid valve. A LiBr-water based two-stage absorption chiller/heater, which is characterized by the following: 6. The switching mechanism is characterized in that the cold water supply path and the hot water supply path can be selectively connected to the external air conditioning load side, and is also equipped with an eight-way valve for flowing cooling water into the cooling water path during cooling. LiBr-water system two-stage absorption type chilled/hot water device according to claim 5.