JP2642048B2 - Heat storage type air conditioner using midnight power - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerative cooling and heating system using midnight power.

[0002]

2. Description of the Related Art As a regenerative cooling / heating device using nighttime power as a power source to level the difference between daytime and midnight power loads, as shown in FIG. And a condenser 10 for liquefying the compressed chlorofluorocarbon gas through the cooling water 107.
2, an expansion valve 106 for lowering the pressure of Freon, an evaporator 103 for cooling or heating water supplied from the heat storage tank 105, and a heat storage tank 105 for storing cold or hot water generated by the evaporator 103. I was During the cooling operation, the compressor 101 is driven by the midnight power and the chlorofluorocarbon is circulated in the direction of the arrow in FIG. 5 so that the cold water is stored in the heat storage tank 105, and when the cold water demand for cooling is generated, the heat storage is performed. The cold water in the tank 105 was taken out. Further, during the heating operation, the circulating Freon in the direction of the dashed arrow in FIG. 5 stores hot water in the heat storage tank 105, and when there is a demand for hot water for heating, the heat storage tank 1
The hot water in 05 was taken out.

[0003] By the way, the water used as a heat storage material in the above-mentioned conventional apparatus has a use temperature range of 6 ° C to 12 ° C in the cooling operation mode and 39 ° C to 45 ° C in the heating operation mode. In each case, the size was small, and the amount of heat retained per unit volume was small at 6,000 kilocalories per cubic meter of water. Therefore, the heat storage tank for injecting water was inevitably large, and the cost of the apparatus was high. .

[0004] In order to solve this drawback, the present applicant has filed a Japanese Patent Application No. 5-241938 for a regenerative air-conditioning apparatus comprising a high-temperature heat storage tank using a sensible heat storage material and an absorption refrigerator. According to this regenerative cooling / heating device, thermal energy is stored in the thermal storage tank by midnight power, and when heat output is required, the stored thermal energy is taken out to operate the absorption refrigerator to perform cooling operation or heating operation. Things. In the cooling and heating apparatus having the high-temperature heat storage tank, the heat storage layer can be reduced in size to 1/46 to 1/71 of the conventional water heat storage tank, and the apparatus cost can be significantly reduced.

However, in the regenerative air conditioner having the above-described high-temperature heat storage tank, since the temperature of the heat storage material changes in a wide range of 120 ° C. to 550 ° C., it is difficult to stably extract heat energy from the heat storage tank. There is a problem that there is.

That is, heat is transferred from the heat storage tank to the absorption refrigerator by connecting the heat transfer tube in the heat storage tank and the heat transfer tube in the regenerator of the absorption refrigerator with a closed flow path. It is done by injecting water into it. Water is heated in the heat transfer tube of the heat storage tank to become steam, and the steam is cooled and returned to water in the heat transfer tube of the regenerator. By this heating and cooling, heat energy is transferred from the heat storage tank to the regenerator. By the way, when the temperature of the heat storage material is high, most of the circulating water from the heat storage tank becomes steam and becomes dry steam with a small amount of circulating water, and the heat energy is smoothly taken out by the regenerator. If the temperature is low, water that does not evaporate remains in the circulating water from the heat storage tank and becomes wet steam having a large amount of circulating water. Therefore, the presence of moisture that does not participate in heat transfer deteriorates the circulation of heat energy.

When the flow of steam generated from the heat storage tank deteriorates, the pressure inside the heat transfer pipe inside the heat storage tank and the pressure inside the heat transfer pipe inside the regenerator increase. When the pressure in the heat transfer tube in the heat storage tank increases, the temperature of the generated steam also increases, so that the temperature difference between the heat storage material and the heat storage material decreases and the amount of heat that can be effectively extracted from the heat storage tank decreases. In addition, when the pressure in the heat transfer tube inside the regenerator increases, the temperature of the heat transfer tube increases, and local corrosion becomes severe, and the heat transfer tube is damaged within a short time.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and even if the temperature of the heat storage material changes, the amount of heat taken out of the heat storage tank can be stabilized at a high level without decreasing. It is an object of the present invention to provide a regenerative cooling / heating device using midnight power, which can be taken out and does not cause local corrosion in a heat transfer tube inside a regenerator.

[0009]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides an absorption refrigerator for cooling and / or heating, and a heat storage tank for storing thermal energy serving as a power source of the absorption refrigerator. In the heat storage tank, an electric heater and a heat transfer tube are arranged, and a heat storage material is filled, and heat energy is supplied to the absorption refrigerator using a fluid that changes in gas-liquid phase as a heat medium passing through the heat transfer tube. In the regenerative cooling / heating apparatus, a heat transfer tube in the regenerator is connected to a heat transfer tube in the regenerator in the absorption refrigerator that receives heat energy from the heat storage tank. A flow control valve is provided in the middle of the flow path to the heat transfer tube of the heat storage tank, and the flow control valve detects the outlet temperature and the inlet temperature of the heat transfer tube of the heat storage tank so that the outlet temperature is higher than the inlet temperature. A flow control unit for controlling the flow rate of the fluid is connected. Characterized in that

[0010] Further, between the outlet of the heat transfer tube of the regenerator and the flow control valve, there may be provided an adjusting tank for storing excess fluid accumulated in the tube. Further, the position of the heat transfer tube in the heat storage tank may be lower than the position of the heat transfer tube of the regenerator.

[0011]

The steam generated from the heat transfer tube of the heat storage tank becomes dry steam when no moisture is contained, and has a temperature higher than the saturation temperature. On the other hand, when steam contains moisture, it becomes wet steam and its temperature becomes the saturation temperature. By the way, the steam generated from the heat transfer tube of the heat storage tank is cooled and condensed in the heat transfer tube of the regenerator, and the temperature of the water supplied to the heat transfer tube of the heat storage tank is always in a saturated state since it is in a saturated state. Therefore, if the outlet temperature of the heat transfer tube of the heat storage tank is higher than the inlet temperature, the steam generated from the heat transfer tube of the heat storage tank can be determined to be dry steam, while at the same temperature, it is determined to be wet steam containing moisture. it can.

Therefore, a flow control valve is provided on the inlet side of the heat storage tank to the heat transfer pipe to adjust the amount of water entering the heat transfer pipe of the heat storage tank.
That is, by the flow control unit connected to the flow control valve,
If the inlet temperature and the outlet temperature in the heat transfer tube of the heat storage tank are the same, the flow control valve is operated in a direction to decrease the flow rate of water, and the steam generated from the heat transfer tube of the heat storage tank is dried. In addition, when the outlet temperature of the heat transfer tube of the heat storage tank is higher than the inlet temperature by a certain level or more, the flow rate control valve is operated in a direction to increase the flow rate of the circulating water to increase the transfer amount of the heat energy. To do it.

If a regulating tank is provided between the outlet of the heat transfer pipe of the regenerator and the flow control valve, excess water circulating in the heat transfer pipe is temporarily removed by adjusting the amount of water by the flow control valve. It is possible to store. Furthermore, by installing the regenerator at a higher position than the heat storage tank, heat transfer by steam from the heat storage tank to the regenerator and return of condensed water from the regenerator to the heat storage tank via the heat transfer tube are caused by water and steam. Smooth natural circulation is possible using the difference in specific gravity as power.

[0014]

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

FIG. 1 is a schematic explanatory view showing one embodiment of the regenerative cooling and heating apparatus of the present invention. The present apparatus includes a heat storage tank 1 and a single-effect absorption refrigerator 2.

The heat storage tank 1 has a heat transfer tube 21 and an electric heater 22 arranged inside, and the periphery thereof is filled with magnesia as a heat storage material 23. Then, at midnight, heat is stored in the heat storage tank 1 by energizing the electric heater 22 to heat the heat storage material 23, and when heat output is required, a fluid such as water or the like that changes gas-liquid phase in the heat transfer tube 21. To extract heat energy from the heat storage tank 1 and operate the single-effect absorption refrigerator 2 using this heat energy.

The single-effect absorption refrigerator 2 includes a regenerator 11,
Condenser 13, evaporator 14, absorber 15, and heat exchanger 16
Each of the regenerator 11, the condenser 13, the evaporator 14, and the absorber 15 has a heat transfer tube 2 therein.
4, 25, 26, 27 are provided. An aqueous solution containing lithium bromide as a main component (hereinafter, referred to as “lithium bromide solution”) is injected into the regenerator 11.

The heat transfer tube 21 inside the heat storage tank 1 and the regenerator 1
1 is connected endlessly so as to form a circulation path with the heat transfer pipe 24 inside, and a flow rate for adjusting the flow rate of water flowing in the pipe in the middle of the flow path from the heat transfer pipe 24 to the heat transfer pipe 21. A control valve 41 is provided. The flow control valve 41 is connected to a flow control unit 42 that automatically controls the flow rate of circulating water. The flow control unit 42 receives signals from the temperature sensors 40 and 44 disposed at the inlet and the outlet of the heat transfer tube 21 and reduces the flow rate of the circulating water when the inlet temperature and the outlet temperature are the same. Control is performed to reduce the opening of the flow control valve 41, and if the outlet temperature is higher than the inlet temperature by a certain level or more, the control is performed to increase the opening of the flow control valve 41. Control to increase the number of circulation waterways. In this way, the amount of water entering the heat transfer tube 21 is controlled by the flow control unit 42 to control the flow control valve 41.
Thus, it is possible to maintain the outlet temperature of the heat transfer tube 21 to be always higher than the inlet temperature thereof, and to generate dry steam from the heat transfer tube 21 of the heat storage tank 1.

The cooling operation of the single-effect absorption refrigerator is performed as follows. First, heat transfer tubes 2
Lithium bromide liquid 31 inside regenerator 11 is generated by heat energy taken out via fluids 1 and 24.
Is heated and boiled. Steam 3 generated by this boiling
3 is supplied to the condenser 13 and is cooled and condensed by the cooling water 38 flowing in the heat transfer tube 25.

Next, when the condensed water 35 generated in the condenser 13 is supplied into the evaporator 14, it becomes low-temperature water due to a decrease in pressure. This water is heated in the evaporator 14 by the cold water 39 flowing through the heat transfer tube 26 to become steam 36. At this time, the cold water 39 in the heat transfer tube 26 is deprived of heat and used for cooling.

On the other hand, the water vapor 36 supplied to the absorber 15
Is absorbed in the lithium bromide liquid 31 which is concentrated in the regenerator 11 and supplied through the heat exchanger 16 in the absorber 15. Then, the lithium bromide liquid 32 having absorbed the water vapor is returned to the regenerator 11 again through the heat exchanger 16.

Next, in the heating operation of the single-effect absorption refrigerator, the cooling water 38 in the cooling operation is heated by stopping the flow of the cooling water 38 passing through the heat transfer tube 25 of the condenser 13. It is used for heating instead of hot water. At this time, the same amount of heat as the amount of heat supplied to the regenerator 11 is the heating amount of heat.
In the drawing, reference numerals 45 and 46 denote circulation pumps.

The maximum temperature of the heat storage material during the cooling / heating operation is set to 5 due to the limitation of the insulation resistance of the electric heater 22.
At 50 ° C., the minimum temperature was set to 120 ° C. due to the limitation of the effective temperature of the single-effect absorption refrigerator. The heat storage material 23 is a solid heat storage material of magnetite or magnesia whose vapor partial pressure is equal to or lower than the atmosphere (preferably almost 0) under operating conditions.
A liquid heat storage material such as a mixture of sodium nitrate, sodium nitrite and potassium nitrate is suitable.

FIG. 2 shows another embodiment of the regenerative cooling / heating apparatus of the present invention.
The point is that an adjustment tank 43 is provided between the outlet of the heat transfer tube 24 of the regenerator 11 and the flow rate control valve 41. This adjustment tank 4
The internal volume of 3 is substantially equal to the volume of water injected into the circulation channel including the heat transfer tubes 21 and 24. Due to the presence of the adjustment tank 43, when the opening of the flow control valve 41 is reduced, the circulating water
4 so that it does not accumulate inside.

If circulating water accumulates in the heat transfer tube 24,
Since the effective heat transfer area of the heat transfer tube 24 decreases and the pressure in the heat transfer tube 21 in the heat storage tank 1 and the pressure in the heat transfer tube 24 inside the regenerator 11 increase to inhibit circulation of water and steam, The inconvenience accompanying this can be eliminated by the adjustment tank 43. That is, the heat transfer tube 2
Heat transfer concentrates on a part of the heat transfer surface due to the decrease of the effective heat transfer area of No. 4, which causes inconvenience that the local heat transfer tube is corroded intensely and may be damaged in a short time. The inconvenience that the amount of heat taken out from the heat storage tank 1 decreases because the steam temperature increases due to an increase in the pressure in the heat transfer tube 21 in the heat transfer tube 1 can be eliminated.

The graph shown in FIG. 3 shows an outer diameter of 12.7 mm,
A heat storage tank having a heat transfer tube having a wall thickness of 0.8 mm and a length of 30 m, under the conditions of a pushing pressure of 2 mAq and generating 1 atg of steam, the steam generated by the flow control valve 41 in the apparatus of the present invention is dried. The comparison shows the amount of heat taken out of the heat storage tank when the control and adjustment tank 43 is provided and when there is no countermeasure. According to this,
It can be seen that in the apparatus of the present invention, even when the temperature of the heat storage material is 300 ° C. or lower, the amount of heat extracted from the heat storage tank is stably performed, as compared with the case where no measures are taken.

FIG. 4 shows still another embodiment of the regenerative air conditioner of the present invention. In this embodiment, the position of the regenerator 11 is set higher than that of the regenerator 1. It is arranged. According to this, using the difference in specific gravity between water and steam as power for circulation, the natural circulation in which steam generated from the heat transfer tube 23 is condensed in the heat transfer tube 24 and returned to water, and becomes steam again in the heat transfer tube 23. Easy, heat storage tank 1
The heat transfer to the regenerator 11 is smoothly performed.

In each of the following embodiments, a single-effect device is used for the absorption refrigerator, but it goes without saying that the present invention can also be applied to a double-effect device.

[0029]

As described above, according to the regenerative air-conditioning system using late-night power of the present invention, by providing a flow control valve for adjusting the amount of water entering the heat transfer tube of the heat storage tank, the transfer of the heat storage tank is achieved. Since the steam generated from the heat tube becomes dry steam,
This has the effect of suppressing the problem that the amount of heat extracted from the heat storage tank decreases and the problem that local corrosion occurs in the heat transfer tube inside the regenerator (claim 1).

Further, by providing an adjusting tank for preventing water from collecting in the heat transfer tube of the regenerator, the heat transfer surface of the heat transfer tube of the regenerator can be used evenly and the heat transfer in the heat storage tank can be performed. Since the pressure in the heat pipe is reduced and the steam temperature is lowered, a major cause of corrosion of the heat transfer pipe is eliminated, and moreover, there is an effect that the amount of heat taken out of the heat storage tank can be stably taken out at a high level. .

Further, by providing an adjusting tank for preventing water from collecting in the heat transfer tube of the regenerator, the heat transfer surface of the heat transfer tube of the regenerator can be used evenly and the heat transfer in the heat storage tank can be performed. Since the pressure in the heat pipe is reduced and the steam temperature is lowered, a major cause of corrosion of the heat transfer pipe is eliminated, and moreover, there is an effect that the amount of heat taken out of the heat storage tank can be stably taken out at a high level. .

Further, by arranging the regenerator at a position higher than the heat storage tank, water and steam can be circulated without using a circulation pump, so that there is an effect that the apparatus cost and the operating cost can be reduced. (Claim 3).

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing an embodiment of the apparatus of the present invention.

FIG. 2 is a schematic explanatory view showing another embodiment of the device of the present invention.

FIG. 3 is an explanatory diagram showing the effect of the apparatus of the present invention in a graph.

FIG. 4 is a schematic explanatory view showing still another embodiment of the device of the present invention.

FIG. 5 is a schematic explanatory view showing an example of a conventional device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 heat storage tank 2 absorption refrigerator 11 regenerator 21 heat transfer tube of heat storage tank 22 electric heater 23 heat storage material 24 heat transfer tube of regenerator 41 flow control valve 42 flow control unit 43 adjustment tank

Claims (3)

(57) [Claims] 1. An absorption refrigerator (2) for cooling and / or heating, and a heat storage tank (1) for storing thermal energy serving as a power source of the absorption refrigerator. An electric heater (22) and a heat transfer tube (21) are arranged in the parentheses, and a heat storage material is filled therein to absorb heat energy by using a fluid that undergoes a gas-liquid phase change in a heat medium passing through the heat transfer tube (21). In the regenerative cooling / heating device to be supplied to the refrigerating machine (2), the regenerator in the absorption refrigerating machine (2) which receives the heat energy from the heat transfer tube (21) in the regenerative tank (1) and the regenerator (1) The heat transfer tube (24) in the regenerator (11) is connected to form a circulation path, and the heat transfer tube (24) of the regenerator is connected to the heat transfer tube (2) of the heat storage tank.
A flow control valve (41) is provided in the middle of the flow path to 1), and the flow control valve (41) detects the outlet temperature and the inlet temperature of the heat transfer tube (21) of the heat storage tank and changes the outlet temperature to the inlet temperature. A flow control unit (4) for controlling the flow rate of the fluid so as to be higher.
(2) A regenerative cooling / heating device utilizing midnight power, wherein the device is connected to (2). 2. An adjusting tank (43) is provided between an outlet of a heat transfer tube (24) of a regenerator and a flow control valve (41) for storing excess fluid accumulated in the tube. The regenerative cooling and heating device using midnight power according to claim 1. 3. The heat transfer tube according to claim 1, wherein a position of the heat transfer tube in the heat storage tank is lower than a position of the heat transfer tube of the regenerator. A regenerative cooling and heating system that uses midnight power.