JPH0293258A - Concentration difference heat accumulating device and operation method - Google Patents

Abstract

PURPOSE:To enable reduction of a quantity of a cooling heat during heat emission operation by a method wherein a bypass piping running around a heat exchanger is installed to pipings by means of which a condensing and diluting device is connected to a heat accumulating liquid storage tank through a heat exchanger, and a flow passage for heat accumulating liquid is switched to either the heat exchanger or the bypass piping according to a set liquid temperature. CONSTITUTION:A bypass piping 20 bypassing a heat exchanger 12 is installed to pipings 8 and 9 on the feed side through which a heat accumulating liquid storage tank 6 and a condensing and diluting device 2 are intercoupled. Liquid temperature measuring device 21 and 22 are installed to the piping 8 on the feed side and a piping 10 on the discharge side, respectively. Solenoid on-off valves 23 and 24 are mounted in a position closer to the heat exchanger 12 side than the branch point of the bypass piping 20 from the piping 8 on the feed side and to the bypass piping, respectively. Further, a measuring computing device 25 to output a signal, by means of which the solenoid on-off valves 23 and 24 are opened and closed, by means of temperature signals detected by the liquid temperature measuring devices 21 and 22 is provided.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a concentration difference heat storage device, and in particular, a concentration difference heat storage device suitable for improving heat recovery efficiency and downsizing a cooling device installed in the device. Concerning equipment and operating methods.

[Conventional technology]

For example, as a concentration difference heat storage device used in an absorption refrigerator, a proposal described in Japanese Patent Application Laid-open No. 195575/1983 is known. This proposal is structured as shown in FIG. In the figure, a concentrator/diluter 2 and a condenser/evaporator 3 are installed in a container 1, and cooling and heating pipes 4 and 5 are installed in each of them. Condenser 3. Heating tube 4. Acts as a cooling pipe 5, and serves as a diluter 2 during heat dissipation operation. Evaporator 3. Cooling pipe 4.
It acts as a heating tube 5. Further, the heat storage liquid storage tank 6 is a container that stores a concentrated liquid and a diluted heat storage liquid, respectively, and the refrigerant storage tank 7 is a container that stores a refrigerant. Heat storage liquid storage tank 6
A supply side pipe 8.9 and a discharge side pipe 10.11 are connected between the concentrator and diluter 2, and these pipes 8,
A heat exchanger 12 is provided between 9 and 10.11. Similarly, a supply side pipe 13.14 and a discharge side pipe 15.16 are connected between the refrigerant storage tank 7 and the condenser/evaporator 3, and a heat pipe is connected between these pipes 13.14 and 15°16. An exchanger 17 is provided.

In addition, the supply side pipes 8 and 13 are equipped with pumps 18 and 19, respectively.
is installed.

In the conventional concentration differential heat storage device configured as described above, a liquid having a water vapor pressure lower than that of the refrigerant is used as the heat storage liquid, and first, during heat storage operation, a low concentration heat storage liquid is pumped through the pipes 8 and 9 by the pump 18. The liquid is introduced into the concentrator 2, and heated by supplying the high temperature liquid to the heating tube 4. The steam generated at this time is
The water is introduced into the condenser 3, which is maintained at the same pressure as the condenser 2, and is condensed. The heat storage liquid that has generated steam and is concentrated is returned to the heat storage liquid storage tank 6 via the pipe 10.11.

At this time, the low concentration heat storage liquid introduced into the concentrator 2 has the same temperature as that stored in the heat storage liquid storage tank 6, which is usually about 25° C., which is room temperature. If the heat storage liquid at this temperature is supplied as it is to the concentrator 2, it is necessary to raise the temperature until it evaporates, that is, to heat the sensible heat with the heating tube 4.

On the other hand, the heat storage liquid that is concentrated and returned to the heat storage liquid storage tank 6 is usually 70%
Since the temperature is higher than 0.degree. C., by exchanging heat between the return liquid and the supply liquid using the heat exchanger 12, the temperature of the supply liquid can be increased and the amount of heating related to the sensible heat change can be reduced.

Further, during the heat dissipation operation, the concentrated heat storage liquid mentioned above is introduced into the diluter 2, which absorbs the vapor generated by being heated by the heating tube 5 in the evaporator 3, generates heat, and becomes low in concentration.

In order to cool the heat storage liquid that has generated heat and increased in temperature, a cooling pipe 4 is used.
coolant is flowing into the

[Issues to be Solved by the Invention] However, according to the conventional concentration difference heat storage device configured as described above, the heat storage liquid whose temperature has increased and the concentration has become low during the heat dissipation operation is transferred to the heat storage liquid via the heat exchanger 12. The temperature of the high concentration heat storage liquid introduced into the diluter 2 is increased by exchanging heat with the medium heat storage liquid in the storage tank. Therefore, there is a problem that the amount of cooling heat in the diluter 2 increases or the amount of steam generated in the evaporator 3 decreases.

As a result, the capacity of the cooling equipment must be increased, and the amount of cold heat obtained is reduced if the capacity of the cooling equipment is the same.

An object of the present invention is to provide a concentration difference heat storage device and an operating method that can reduce the amount of cooling heat during heat dissipation operation or increase the amount of cold water heat with the same amount of cooling heat.

[Means to solve the problem]

In order to achieve the above object, the present invention consists of a heat storage liquid concentrator/diluter and a refrigerant condenser/evaporator, each having a heating/diluting device.
A container equipped with cooling pipes, a heat storage liquid storage tank for heat storage liquid and a refrigerant storage tank for refrigerant, which are connected via piping to the concentrator/diluter and condenser/evaporator, respectively, and from the heat storage liquid storage tank to the concentrator/diluter. In a concentration difference heat storage device equipped with a heat exchanger that exchanges heat between the supplied heat storage liquid and the heat storage liquid discharged from the concentrator/diluter to the heat storage liquid storage tank, heat exchange is performed between the concentrator/diluter and the heat storage liquid storage tank. A bypass pipe is provided to bypass the heat exchanger in one of the pipes connected through the heat exchanger, and a liquid temperature measuring means is provided at the heat exchanger inlet of each pipe. A means is provided for switching the flow path to either the heat exchanger or the bypass piping.

[Effect]

According to the above configuration, when the liquid temperature measurement means detects that the temperature of the heat storage liquid in the heat storage liquid storage tank is lower than the temperature of the heat storage liquid discharged from the diluter during heat dissipation operation, the temperature of the heat storage liquid is removed from the heat storage liquid storage tank. By switching the introduction flow path to the diluter to bypass piping using the switching means and introducing it to the diluter without going through a heat exchanger, it is possible to supply the heat storage liquid at room temperature and high concentration to the diluter at the same temperature. can. As a result, by reducing the amount of heat required to cool the diluter and reducing the cooling equipment capacity, or with the same cooling equipment capacity, it is possible to increase the amount of steam generated in the evaporator and increase the cold output. can. In addition, the temperature of the heat storage liquid in the S heat liquid storage tank is
If the temperature is higher than the temperature of the heat storage liquid discharged from the diluter due to operating conditions or weather conditions, the temperature of the heat storage liquid introduced into the diluter via the heat exchanger will be lowered even during heat dissipation in the same way as during heat storage. let

〔Example〕

Hereinafter, one embodiment of the concentration difference heat storage device according to the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. In fig.

Parts that are the same or equivalent to those of the conventional example shown in FIG. 8,
9 is provided with a bypass piping 20 that bypasses the heat exchanger 12, liquid temperature measuring instruments 21 and 22 are provided on each of the supply side piping 8 and the discharge side piping 10, and the bypass piping 2o of the supply side piping 8 is provided.
Electromagnetic on/off valves 23.24 are provided on the heat exchanger 12 side and this bypass piping from the branch point, respectively, and the electromagnetic on/off valves 23.24 are opened/closed based on the temperature signal detected by the liquid temperature measuring device 21.22. The point is that a measurement calculator 25 is provided which outputs a signal. Note that in this embodiment, the refrigerant n tank 7
A side heat exchanger is not required, and the discharge side pipe 10.15 and the supply side pipes 9, 13 are connected by return pipes 26.27, respectively.

The rest of the structure is the same as the conventional example.

Next, the operation of this embodiment will be explained with reference to FIGS. 2 to 5. For example, in an absorption refrigerator, LiBr is used as the heat storage liquid.
Water is used as an aqueous solution and a refrigerant, and water is also used as a heating liquid and a cooling liquid. During heat storage operation, the system shown in Figure 2 is used. In this case, as mentioned above, the container 1 is the concentrator 2. Condenser 3. Heating tube 4. It acts as a cooling pipe 5. A heating liquid having a temperature of about 95° C. is supplied to the heating pipe 4, and a cooling liquid having a temperature of about 30° C. is supplied to the cooling pipe 5. When the heat storage liquid and refrigerant are heated or cooled by 5°C with these heating liquid and cooling liquid, respectively, the heating liquid outlet temperature will be approximately 90°C, the cooling water outlet temperature will be approximately 35°C, and it is assumed that the heat exchange temperature difference is 3°C. Then, a 55% concentration LiBr aqueous solution is transferred from the heat storage liquid storage tank 6 to the concentrator 2 of the container 1, which satisfies the conditions of 0 or more, such that the concentration temperature is about 87°C and the condensation temperature is about 38°C, respectively. heat exchanger 1
2. When introduced via pipe 9, the heat storage liquid is 61.7%
It is concentrated to
and most of the other water flows to the pipe 9 via the pipe 26,
It is mixed with the heat storage liquid supplied from the heat storage liquid storage tank 6.

In addition, the medium with a concentration of 61.7% flowing into the pipe 10 has a temperature of 87%.
℃, heat is transferred to the heat storage liquid from the heat storage liquid storage tank 6 in the heat exchanger 12, and the heat storage liquid is heated from 30℃ to 76.2℃.
Raise the temperature to ℃. Therefore, the amount of heat required for the sensible heat change from 30°C to 76.2°C does not need to be obtained from the heated water.
In addition, since the LiBr aqueous solution with a concentration of 61.7% is cooled to 30°C, even if it is discharged into the heat storage liquid storage tank 6, this storage tank 6
A room temperature storage tank may be used, and the material of the storage tank 6 can be made at low cost. In addition, the water vapor generated in the condenser 2 moves to the condenser 3,
The water is condensed at ℃ and accumulated in the refrigerant storage tank 7.

Next, the action during the heat dissipation operation will be explained with reference to FIGS. 3 and 4. In this case, as mentioned above, container 1 is diluter 2.
．． Evaporator 3. Cooling pipe 4. It acts as a heating tube 5. By flowing cooling water through the cooling pipe 4 and flowing heated water through the heating pipe 5, operating conditions for the diluter 2 and the evaporator 3 are set. For example, a LiBr aqueous solution with a concentration of 61.7% and a temperature of 30° C. is introduced into the diluter 2, absorbs the water vapor generated in the evaporator 3, and is diluted to a concentration of 55%, at the same time raising the temperature.
It is cooled to about 38°C by cooling water.

This heat storage liquid is absorbed by the pump 18, a - part flows to the pipe 9 via the pipe 26, and the other part flows to the pipe 10. Heat exchanger 12. It returns to the heat storage liquid storage tank 6 via the piping 11. At this time, if the heat storage liquid discharged from the pipe 10 has a higher temperature than the heat storage liquid supplied to the diluter 2 through the pipes 8 and 9 as described above, the liquid temperature shown in FIG. Measuring device 2
1.22, this is detected, the electromagnetic on-off valve 23 is closed and 24 is opened via the measurement calculator 25, and the heat storage liquid is caused to flow into the bypass pipe 20. As a result, the heat storage liquid on the supply side does not pass through the heat exchanger 12, so no heat exchange occurs.
The heat storage liquid is introduced into the diluter 2 at about 30°C. Therefore, the amount of cooling heat transferred to the cooling pipe 4 of the diluter 2 can be reduced compared to the case where the heat is introduced via the conventional heat exchanger 12. The water generated in the evaporator 3 and deprived of latent heat cools down to 8°C, and cold water with a water temperature of 11°C is obtained from the outlet of the heating tube 5. In addition, if the temperature of the heat storage liquid discharged from the pipe 10 is lower than that of the heat storage liquid supplied to the diluter 2 through the pipes 8 and 9, the electromagnetic on-off valve 23 is opened and the valve 24 is opened in the same way as during the heat storage operation. When closed, the heat storage liquid on both the supply side and the discharge side flows through the heat exchanger 12 to perform heat exchange and cool the heat storage liquid on the supply side.

Figure 5 shows the results of simulation calculations for the above situation. This figure is a graph showing the relationship between the temperature efficiency Φ of the heat exchanger 12 and the heat recovery rate determined by the amount of heating required during heat storage operation and the amount of cold output obtained during heat dissipation operation. This temperature efficiency Φ is given by the following equation (1).

1-tx Here, T1: High-temperature side inlet temperature T2: High-temperature side outlet temperature tl: Low-temperature side inlet temperature As seen in the diagram, as the heat exchange temperature efficiency Φ on the horizontal axis improves, the heat recovery efficiency improves. .

The solid line shows the case where heat is exchanged via the heat exchanger 12 during both the heat storage operation and the heat radiation operation, and the broken line shows the case where the heat exchanger 12 is not used during the heat radiation operation. It is clear that the heat recovery efficiency of the device is improved.

According to this embodiment, it is possible to reduce the amount of cooling water supplied to the cooling pipe 4 in the diluter 2 during heat dissipation operation, and it is possible to reduce the capacity of a cooling water production device such as a cooling water tower. . On the other hand, if the cooling water production apparatus has the same capacity, the amount of cooling can be improved, and as a result, the amount of heat of the cold water obtained by the heating tube 5 can be increased.

〔Effect of the invention〕

As described above, according to the present invention, a bypass line for the heat exchanger provided in the concentration difference heat storage device is provided, so that during heat storage operation, the temperature of the heat storage liquid supplied to the concentrator is increased to heat the concentrator. By reducing the amount of heat, it is possible to reduce the amount of cooling heat of the diluter or increase the cooling output without using a heat exchanger depending on the operating conditions during heat dissipation operation, thereby achieving energy savings.

[Brief explanation of the drawing]

FIG. 1 is a piping system diagram of an embodiment of the concentration difference heat storage device according to the present invention, and FIGS. 2 and 3 are piping system diagrams during heat storage operation and heat dissipation operation of FIG. 1, respectively. FIGS. 4 and 5 are graphs showing the operating state of the heat storage device according to this embodiment and the relationship between the temperature efficiency and heat recovery rate of the heat exchanger, respectively, and FIG. 6 is an example of a conventional concentration difference heat storage device. It is a piping system diagram shown. 1... Container, 2... Concentrator/diluter, 3... Condensate/
Evaporator. 4.5... Heating/cooler, 6... Heat storage liquid storage tank, 7.
・Refrigerant storage tank, 8, 9. to, 11, 13, 14, 151
16. 26, 27... Piping, 12, 17... Heat exchanger, 18. 19... Pump, 20... Bypass piping, 21° 22... Liquid temperature measuring device, 23. 24. ...Solenoid on-off valve, 25...Measurement calculator. Foil 5 Diplomatic Scars 1 Rib Cup

Claims (1)

[Scope of Claims] 1. A container comprising a heat storage liquid concentrator/diluter and a refrigerant condenser/evaporator, each of which is provided with a heating/cooling pipe, and the concentrator/diluter and the condenser/evaporator. A heat storage liquid storage tank for the heat storage liquid and a refrigerant storage tank for the refrigerant are connected to each of the heat storage liquid and the refrigerant via piping, and the heat storage liquid is supplied from the heat storage liquid storage tank to the concentrator/diluter, and the heat storage liquid storage tank is supplied from the concentrator/diluter to the heat storage liquid storage tank. In a concentration difference heat storage device comprising a heat exchanger for exchanging heat with a heat storage liquid discharged to a heat storage liquid, either one of the pipes connects the concentrator/diluter and the heat storage liquid storage tank via the heat exchanger. A concentration difference heat storage device, characterized in that a bypass pipe is provided to bypass the heat exchanger, and a liquid temperature measuring means is provided at the inlet of each pipe to the heat exchanger. 2. The temperature of each heat storage liquid inlet of the heat exchanger is measured by a liquid temperature measuring means, and when the heat storage liquid is concentrated, the heat is exchanged through the heat exchanger, and when the heat storage liquid is diluted, the heat exchange is performed from the heat storage liquid storage tank. If the temperature of the heat storage liquid flowing into the heat exchanger is higher than the temperature of the heat storage liquid discharged from the concentrator/diluter to the heat exchanger, the heat storage liquid is distributed to a bypass pipe of either one of the heat exchangers. A method of operating a concentration difference heat storage device, characterized in that: