WO2013128778A1 - Heat-transport system - Google Patents

Abstract

A heat-transport system used in a local cooling/heating system or the like balances a reduction in the fluid resistance of a heat-transfer medium during the transport of cold or heat, and an improvement in the heat-exchange efficiency of a heat-exchange unit. To this end, the heat-transport system transports a heat-transfer medium, which has been cooled in a heat exchange by a heat exchanger on the side where a chiller or freezer is used, to a heat exchanger at a demand source. The heat-transfer medium includes a cold-storage material having latent heat in the temperature range of the use-side heat exchanger. In addition, the heat-transfer-medium line connecting the use-side heat exchanger and the demand-source heat exchanger is provided with a tube-resistance reduction means.

Description

Heat transfer system

It is related to a heat transfer system that connects a heat source and a facility that requires air conditioning with a long pipe and transports the heat or cold of the heat source to a facility that requires air conditioning, and is particularly suitable for large-scale buildings and district heating and cooling systems. The present invention relates to a heat transfer system.

Conventionally, heat transfer systems used in large-scale buildings and district heating and cooling systems connect piping between the heat source and facilities that require air conditioning without using a packaged air conditioner that exchanges heat with the outside air via a refrigerant. The cold / hot water is circulated in the pipe. In the case of cooling, a so-called fan coil unit system is known in which cold / hot water generated on the heat source side is guided to a facility that needs air conditioning by a pump or the like, and air is blown indoors by a fan or the like in a facility that requires air conditioning.

In such a large-scale heat source facility, the piping distance between the heat source and the facility that requires air conditioning may range from several hundred meters to several kilometers, and the power to transport the cold / hot water circulating in the piping is the heat source system. It accounts for about 10 to 30% of the total power consumption, and cannot be ignored. Therefore, energy saving of conveyance power in a large-scale heat source facility is an important issue. Thus, an example of a method for reducing such conveyance power is described in Patent Document 1.

In the heat transfer system described in this publication, by using a phase change heat storage material, the heat transfer efficiency, which is the ratio of the transfer heat quantity to the transfer power, is increased, and the power of the pump is reduced. Specifically, the heat transfer material is an aqueous liquid in which a polymer material is added to a phase change heat storage material, and the phase change heat storage material is configured in a state of a micro latent heat storage microcapsule housed in a resin coating material, The phase change temperature is assumed to be in the temperature range between the heat supply temperature on the heat supply device side and the heat release temperature on the heat utilization device side. On the other hand, as the polymer substance, a material that can also be used as a surfactant such as polyethylene oxide is used to reduce the flow resistance.

Another method for reducing the flow resistance of the heat transfer system is described in Patent Document 2. In the air conditioning system using the latent heat transport hydrate slurry described in this publication, the hydrate slurry in which the hydrate having latent heat and the heat density larger than water is turbid is used as the heat medium of the air conditioning system. Different hydrate slurries are used for cooling and heating. Specifically, a cationic resistance reducing agent that is a surfactant and a clathrate hydrate slurry to which a counter ion of the cationic resistance reducing agent is added as a cooling medium at the time of cooling. An inorganic hydrate slurry to which a counter ion of the same cationic resistance reducing agent is added is used as a heat medium during heating.

This heat medium undergoes a phase change within the temperature range of the heat supply temperature on the heat supply device side and the heat release temperature on the heat utilization device side, so that compared to the heat medium that uses the latent heat of ice that freezes at 0 ° C. or less. The following problems can be solved. In order to produce ice, a heat source facility capable of bringing the heat transport medium into a state of 0 ° C. or lower is necessary. Since the heat source equipment of a normal air conditioning system is about 4 to 7 ° C., a large-scale or high-grade equipment is required as compared with ordinary equipment. In addition, since the temperature below 0 ° C is produced, the COP (coefficient of performance) indicating the performance of the heat source decreases, countermeasures against the occurrence of condensation due to the temperature below 0 ° C, ice clogging in the piping, etc. Countermeasures are also required.

Furthermore, in order to reduce energy loss during fluid conveyance, regardless of the state of liquid, gas, etc., pressurize the fluid flowing in the pipeline, repeat acceleration and deceleration, and pulsate and transfer the fluid Is described in Patent Document 3. In the fluid conveyance method described in this publication, if there is no pulsation, the fluid in the pipeline in a turbulent state is pulsated to reduce frictional resistance, and the fluid can be conveyed with less energy.

JP 2003-262482 A JP 2005-29591 A International Publication No. 2009/044744

In the conventional heat transfer system described in Patent Document 1, a polymer material such as polyethylene oxide that can also be used as a surfactant is used for the heat transfer medium. Therefore, the flow resistance of the heat transfer medium in the air conditioning equipment is reduced. It can be expected to reduce. However, although the surfactant is effective in reducing the flow resistance of the fluid, its heat exchange performance is not necessarily high as a heat exchange medium compared to water or a refrigerant.

Even in the air conditioning system using the latent heat transport hydrate slurry described in Patent Document 2, since the surfactant is used to reduce the flow resistance of the hydrate slurry, the flow resistance is reduced. In the heat exchange part of the system, the heat exchange performance may be reduced.

In the fluid transfer device described in Patent Document 3, pulsation is applied to the fluid to be transported so that the fluid is transported in the laminar flow direction, thereby enabling transport with less resistance than in turbulent transport. However, since this fluid transfer device focuses only on the flow resistance of the fluid to be transported, it can be used for transporting a heat medium such as an air conditioner to improve heat exchange efficiency. It is not considered enough. In an air conditioning facility, it is desired that both the flow resistance in fluid transportation and the heat exchange efficiency in the heat exchange section be improved.

The present invention has been made in view of the above-mentioned problems of the prior art, and its purpose is to reduce flow resistance in transportation of a heat medium and heat exchange in a heat exchange section in a large heat source facility such as a district cooling and heating system. There is a balance between improving efficiency. Another object of the present invention is to provide an inexpensive system that does not cause condensation or clogging of piping while simultaneously reducing the flow resistance and improving the heat exchange efficiency.

A feature of the present invention that achieves the above object is that in the heat transfer system for transferring the heat medium whose temperature has been reduced by heat exchange with the use side heat exchanger of the chiller or refrigerator to the heat exchanger of the demand source, the heat The medium includes a cold storage material having latent heat in the temperature range of the use side heat exchanger and having a heat capacity larger than that of water, and heat that connects the use side heat exchanger and the heat exchanger of the demand source. The pipe resistance reduction means is provided in the medium line.

In this aspect, it is preferable that the pipe resistance reducing means includes a rotation speed variable pump arranged in the line of the heat medium and capable of providing a periodic flow velocity fluctuation, and the pipe resistance reducing means is disposed on the heat medium. It is desirable to provide a plurality of control devices that are arranged in the line and synchronize the flow rate fluctuation cycles of the plurality of arranged pipe resistance reducing means. Further, the cycle of the flow velocity fluctuation is preferably 10 seconds or more, and the cold storage material may be an organic substance or an inorganic substance such as paraffin wax. The organic substance is preferably formed in a microcapsule state because there is concern about separability from water and adhesion in a heat exchanger.

Furthermore, the cold storage material is preferably a liquid in which about 10 to 40% of an organic substance such as paraffin wax is mixed with water, and the cold storage material may be configured in a microcapsule state.

According to the present invention, the heat storage material having latent heat in the air conditioning temperature zone is used as the heat transport medium, and this heat transport medium is stably maintained as a pulsating flow in the pipe according to the air conditioning load. It is possible to achieve both reduction of resistance and improvement of heat exchange efficiency in the heat exchange section. Moreover, since it has latent heat in the air-conditioning temperature zone, it is possible to achieve both a reduction in flow resistance and an improvement in heat exchange efficiency in the heat exchange section without causing dew condensation or piping clogging.

It is an arrangement schematic diagram of a district air conditioning system concerning the present invention. It is a piping system diagram of the district cooling and heating system shown in FIG. It is a piping system diagram of one Example of the heat transfer system with which the district cooling and heating system shown in FIG. 1 is provided. It is a figure explaining the flow velocity fluctuation | variation. It is a piping system diagram of other examples of a heat transfer system.

Hereinafter, an embodiment of a heat transfer system according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of a district cooling and heating district 10 to which a district cooling and heating system having a heat transfer system is applied. FIG. 2 is a piping diagram of the district cooling / heating system 80 applied to the district cooling / heating district 10 shown in FIG.

The district heating / cooling district 10 to which the district heating / cooling system 80 is applied is an area where the iron road 14 and a number of roads 12 run through the mesh. For example, in the example shown in FIG. Covers the block area. In this example, fluids used for air conditioning and hot water supply such as hot water, cold water, and steam are supplied to the plurality of buildings 16a to 16j via the piping facility 30. Incidentally, the buildings 16a, 16b and 16j are high-rise office buildings, and the buildings 16c and 16h are convention halls. The buildings 16d and 16g are general hotels, and the buildings 16e and 16f are low-rise general hotels.

The piping 30 for supplying cold water, hot water, steam, etc. to the plurality of buildings 16a to 16j has a diameter of 500 to 1000 mm and a total length of 8 km in the large district heating and cooling district 10. In order to supply cold water, hot water, steam, and the like, a machine building 21 and a heat exchange building 23, which will be described in detail later, are provided in one corner of the district heating and cooling district.

Details of the piping 30 will be described with reference to FIG. In the machine building 21, a heat source device for supplying cold water, hot water, hot water supply, and steam to the district air conditioning district 10 is installed. As a heat source machine, a heat pump chiller 110, a turbo refrigerator 120, and a steam-fired double-effect absorption chiller / heater 140 are provided, and a boiler 150 is installed as a heat source of the absorption chiller 140.

The heat pump chiller 110 is connected to a compressor 115 driven by a gas engine or an electric motor 115b, a heat source side heat exchanger 111 connected to the compressor 115 via a four-way valve 114, and acting as a condenser during cooling, Sometimes the use side heat exchanger 112 acting as an evaporator and the decompression means 113 such as an expansion valve are main components. The turbo refrigerator 120 includes a turbo refrigerator main body 125 driven by an electric motor 125b, a condenser 121, a decompression means 123 such as an expansion valve, and an evaporator 122.

The dual-effect absorption chiller / heater 140 includes a high-temperature regenerator 141 that uses steam generated in the boiler 150 as a heating source, and a low-temperature regenerator that further concentrates an absorbing solution such as an aqueous lithium bromide solution concentrated by the high-temperature regenerator 141. 142, a condenser 143 that condenses the steam generated in the low-temperature regenerator 142, an evaporator 145 that evaporates water generated in the condenser 143, and an absorber 144 that absorbs the steam generated in the evaporator 145. .

On the other hand, in the heat exchange building 23, cooling towers for heat exchange between the heat pump chiller 110, the turbo refrigerator 120, the absorption chiller / heater 140, and the like are arranged. Specifically, in the heat pump chiller 110, a cooling tower 117 for cooling the cooling water that exchanges heat with the refrigerant that circulates in the heat source side heat exchanger 111 is arranged in the heat exchange building 23. Even in the centrifugal chiller, a cooling tower 127 for cooling the cooling water that exchanges heat with the refrigerant flowing in the condenser 121 is disposed in the heat exchange building 23. Further, in the absorption chiller / heater 140, a cooling tower 132 is provided for the cooling water that has passed through the absorber 144 and the condenser 143 to exchange heat with the outside air. A steam / hot water heat exchanger 151 for converting a part of the steam generated in the boiler 150 into hot water is also arranged in the heat exchange building 23.

In the district cooling / heating system 100 configured as described above, when the heat pump chiller 110 is in a cooling operation, the refrigerant compressed by the compressor 115 is converted into the four-way valve 114, the heat source side heat exchanger 111, the decompression means 113, and the use side heat exchanger. The refrigerant line 212 is circulated in the order of 112 and the four-way valve 114. At that time, the heat source side heat exchanger 111 exchanges heat with the cooling water flowing through the cooling water line 211, and the use side heat exchanger exchanges heat with the cold water flowing through the cold / hot water lines 213 and 214. Here, the cold / hot water line 213 is branched into two lines 261 and 262 having switching valves 116a and 116b, respectively. During the cooling operation, the switching valve 116a is opened and the switching valve 116b is closed. Similarly, the cold / hot water line 214 is also branched into two lines 263 and 264 having switching valves 116c and 116d, respectively. During the cooling operation, the switching valve 116d is opened and the switching valve 116c is switched to the closed state. During heating operation, the opening and closing of the switching valves 116a to 116d are switched in reverse.

In the turbo refrigerator 120, the cooling water flowing through the cooling water line 221 is exchanged with the condenser 121 provided in the refrigerant line 222, and further, heat is exchanged with the outside air in the cooling tower 127. Further, the refrigerant circulating in the evaporator 122 and the cold water flowing in the cold water lines 223 and 224 exchange heat. The cold water generated in the evaporator is supplied to the buildings 16a to 16j which are demand sources.

The cold / warm water generated by the absorption chiller / heater 140 is branched from the chill / warm water lines 233 and 234 and guided to the chilled water lines 241 and 243 and the hot water lines 242 and 244 having switching valves 131a to 131d. During the cooling operation, the switching valves 131a and 131c are switched to open, and the switching valves 131b and 131d are switched to close. During heating operation, opening and closing of the switching valves 131a to 131d is reversed.

Steam generated in the boiler 150 is guided from the steam line 251 to the absorption chiller / heater 140 and returned to the boiler through the steam line 252. Steam lines 155 and 156 branched from the steam lines 251 and 252 and led to the steam / hot water heat exchanger 151 are provided. On the other hand, the hot water generated in the steam / hot water heat exchanger 151 is guided to the hot water lines 261 and 263 by the hot water lines 157 and 158 with the open / close valves 152 and 153 interposed therebetween. Fuel gas is supplied to the boiler 150 from the gas line 253. Steam lines 255 and 256 are also provided so that steam can be supplied to the buildings 16a to 16j.

The cold / hot water generated in the machine building 21 and the heat exchange building 23 is sent to the buildings 16a to 16j from the hot water line 261 and the cold water line 262 which are main pipes of the cold / hot water, and passes through the hot water line 263 and the cold water line 264. 21 and the heat exchange building 23. Here, the cool / hot water lines 261 to 264 are provided with pumps 161 to 164 for liquid feeding. A cold storage tank 170 is provided in the middle of the cold water return line 164, and the cold water line (outward) 262 passes through the cold storage tank 170. Further, booster pumps 165 and 167 are provided in the cold / warm water feed lines 261 and 262, and are driven by inverters 166 and 168, respectively.

From the hot water lines 261 and 263 and the cold water lines 262 and 264 which are the main pipes of the cold and hot water, the individual hot water lines 331 and 333 in the vicinity of the buildings 16a to 16j; ...; 391 and 393 and the cold water lines 332 and 334; 392 and 394 are branched. Some of the branch lines are also provided with booster pumps 181a to 181d and inverters 182a to 182d.

Thus, in the district cooling and heating system 100, a large number of pipes are laid, and reducing the pipe resistance of the pipe system leads to energy saving. Therefore, in the present invention, by controlling the flow of cold water and hot water in the piping system and changing the type of circulating fluid, the flow resistance is reduced, and the heat transfer efficiency, which is the ratio of the transfer heat amount to the transfer power, is improved, and the heat source The reduction in efficiency coefficient of performance COP is suppressed. A heat transfer system that suppresses the decrease in the flow resistance of the piping system and the decrease in the heat source COP will be described with reference to FIGS.

FIG. 3 is a diagram showing an embodiment of a piping system of a heat transfer system in which a part of the piping in the district cooling and heating system 100 is extracted, and the use of the chiller 110 or the refrigerators 120 and 140 which are heat source devices The system | strain after the side heat exchanger 400 is shown. The refrigerant pipes 400c and 400d of the use side heat exchanger (evaporator) 400 are compressed by a compressor or the like, condensed by a condenser, then decompressed by an expansion means, and a refrigerant whose temperature has decreased flows. The cold water lines 400a and 400b through which the circulating water that exchanges heat with the low-temperature refrigerant circulates and the cold water lines 420c, 420d; 430c, and 430d branched from the cold water line are connected to the use side heat exchanger (evaporator).

Here, the liquid (heat medium) flowing in the cold water lines 400a and 400b is a liquid that causes a change in latent heat in the temperature range (4 to 12 ° C.) of the refrigerant flowing into the use-side heat exchanger 400. Specifically, it is a liquid obtained by mixing about 10 to 40% of an organic substance such as paraffin wax in water, or a liquid obtained by mixing about 10 to 40% of an inorganic substance. The organic substance is preferably configured in the form of a microcapsule because there are concerns about separability from water and adhesion in a heat exchanger. The heat medium returns from the cold water return lines 400b, 420d, and 430d at, for example, 12 ° C., flows into the use-side heat exchanger 400 in a liquid state, exchanges heat with the refrigerant, and decreases in temperature to, for example, about 7 ° C. The property changes to the mixed state and is led to the cold water (outward) lines 400a, 420c, 430c, and sent by the pump 402 to the heat exchangers 410, 420, 430 of the demand sources (each building 16a-16j).

As a feature of the present invention, the flow sent from the pump 402 has a periodic speed fluctuation to reduce the pipe resistance. Therefore, the pump 402 is driven by the inverter drive motor 404, and the rotation speed is variable. A sensor 406 capable of detecting fluctuations in the flow rate of the heat medium in the chilled water outgoing line 400a is attached in the vicinity of the pump 402, in this embodiment, on the upstream side. These constitute pipe resistance reduction means.

In the heat exchangers 410, 420, and 430 that are the demand sources, the heat exchangers 410, 420, and 430 further exchange heat with the circulating water flowing through the cold water lines 410a and 410b; 420a and 420b; In addition, if the heat exchangers 410, 420, and 430 of the demand source are fan coils or the like, a blower fan is arranged instead of the cold water lines 410a and 410b; 420a and 420b; 430a and 430b.

The booster pumps 414, 424, and 434 are arranged at intervals in the cold water going lines 400a, 420c, and 430c. Each booster pump 414, 424, 434 is driven by an inverter drive motor 416, 426, 436 so that the number of rotations is variable. Sensors 412, 422, and 432 that can detect fluctuations in the flow rate of the heat medium flowing into the booster pumps 414, 424, and 434 are attached to the upstream side of each booster pump.

Fluctuations in the flow rate of the heat medium in the chilled water outgoing lines 400a, 420c, 430c detected by the sensors 406, 412, 422, 432 are input to the control device 440 via signal lines 406a, 412a, 422a, 432a. In addition, command signals are output from the control device 440 to the inverter drive motors 404, 416, 426, and 436 that drive the pump 402 and the booster pumps 414, 424, and 434 through the signal lines 404b, 416b, 426b, and 436b. .

The control device 440 instructs the inverter drive motor 404 so that the flow rate of the heat medium flowing in the cold water line 400a periodically varies. At that time, the flow rate is set so that the average value of the flow velocity satisfies the required cooling heat quantity from the demand source.

The control device gives the booster pumps 414, 424, and 434 positioned at several tens of meters or more away from the pump 402 to drive signals that are synchronized with the periodic pulsation generated by the pump 402. That is, on the downstream side of the cold water line 400a, there is a possibility that a flow rate corresponding to the flow resistance flows through the branch lines 420c, 420d; is there. Therefore, in order to cause the booster pumps 414, 424, and 434 to generate a pulsating flow that is synchronized with the pump 402, pulsations are generated according to fluctuations in the flow rate of the heat medium detected by the sensors 412, 422, and 432.

At this time, the booster pumps 414, 424, and 434 are not particular about being arranged at the illustrated positions. You may install in the cold water return line 400b, 420d, 430d after the flow in a pipe | tube is disturbed by the heat exchangers 410, 420, 430 of a demand source.

Fig. 4 shows an example of a cycle that gives flow velocity fluctuations. The horizontal axis represents the average flow velocity, and the vertical axis represents the period. There is a suitable period depending on the pipe diameter. In a district heating and cooling system or the like, a flow rate of 2 to 4 m / s is usually adopted, and the fluctuation period is preferably 10 seconds or more. Further, since the cycle changes depending on the pipe diameter, the branch line booster pumps 181a to 181d, which may have different pipe diameters in conjunction with the above-described pumps 161 to 167 in FIG. 2, are suitable for the branch line pipe diameter. A pulsation corresponding to the fluctuation of the flow velocity may be generated at a simple cycle. For this branch line, heat exchange with the heat medium is performed in the heat exchangers in the buildings 16a to 16c and 16j, which are facilities that require air conditioning, and the flow velocity is set so as to satisfy the heat exchange performance in the heat exchanger. May be varied. That is, the branch line should be operated under suitable conditions in consideration of both the resistance reduction of the pipe and the heat exchange performance.

Thereby, the flow resistance of the heat medium can be reduced, and the driving power of the pumps 402, 414, 424, 434 shown in FIG. 3 can be reduced. Further, since the state of the heat medium is changed by latent heat in the cooling temperature operation state of the use side heat exchanger 400, the heat capacity that can be used for cooling is increased as compared with the case of using water, and the heat transfer efficiency can be improved. In addition, since the temperature range of the refrigerant can be set to 4 to 7 ° C., it is possible to suppress a decrease in COP of the heat source.

FIG. 5 shows another embodiment of the heat transfer system according to the present invention. This embodiment is different from the embodiment of FIG. 3 in that a cold storage tank 550 is provided. Others are the same as the heat transfer system of FIG. Refrigerant lines 500c and 500d and cold water lines 550a and 550b are connected to the chiller or refrigerator use side heat exchanger 500. A cold storage tank 550 is arranged in the middle of the cold water lines 550a and 550b. The heat medium in the cold water lines 550 a and 550 b is circulated between the use side heat exchanger 500 and the cold storage tank 550 by the pump 552.

Cold water lines 500a, 500b; 520c, 520d; 530c, 530d through which a heat medium circulates are formed between the heat exchangers 510, 520, 530 on the demand source side and the cold storage tank 550. Further, pumps 514, 524, and 534 and inverter drive motors 516, 526, and 536 for driving the pumps 514, 524, and 534 are provided in the cold water outgoing lines 500a, 520c, and 530c, and the vicinity of the pumps 514, 524, and 534 is provided. In addition, sensors 512, 522, and 532 that can detect fluctuations in the flow rate of the heat medium in the chilled water outgoing lines 500a, 520c, and 530c are disposed on the upstream side. Further, a pump 502 and an inverter drive motor 504 for driving the pump 502 are arranged in the chilled water outgoing line 500a near the cold storage tank 550 and upstream of the point where the chilled water lines 520c and 530c branch. On the upstream side, a sensor 506 capable of detecting the speed fluctuation of the heat medium flowing in the cold water line 500a is provided.

The heat medium speed fluctuation data detected by the sensors 506, 512, 522, and 532 is input to the control device 540 via the signal lines 506a, 512a, 522a, and 532a. On the other hand, the control device 540 outputs a command signal to the inverter drive motors 504, 516, 526, and 536 via signal lines 504b, 516b, 526b, and 536b.

If the distance from the cold storage tank 540 to each heat exchanger 510, 520, 530 of the demand source is long, it is conceivable that the booster pumps 514, 524, 534 are installed in the chilled water outgoing lines 500a, 520c, 530c. 524 and 534 are given speed fluctuations synchronized with the speed fluctuation of the pump 502. Therefore, the control device 540 gives a variable speed command to the inverter drive motors 516, 526, and 536 based on the detection data of the sensors 512, 522, and 532.

In addition, as a usage method of the cool storage tank 550, it cools in the heat medium in the cool storage tank 550 when there is little nighttime cooling load. When the capacity of the heat medium in the cold water lines 500a, 500b; 520c, 520d; 530c, 530d on the demand source side is larger than the capacity of the cold storage tank 540, the pumps 502, 514, 524 even if the cooling load is small. 534 is operated to cool the cold water lines 500a, 500b; 520c, 520d; 530c, 530d. At this time, the control device 540 has power for circulating the heat medium in the cold water lines 500a, 500b; 520c, 520d; 530c, 530d, power for circulating the heat medium in the cold water lines 550a, 550b, and pumps 552, 502, 514 at that time. The heat load (heat input loss) of 524, 534 and the like are calculated and controlled so as to minimize them. In cold storage in the chilled water lines 500a, 500b; 520c, 520d; 530c, 530d, it is not necessary to store cold in all lines, and it is desirable from the viewpoint of energy saving to keep the minimum amount based on the prediction of the cooling load.

During the cooling operation in the daytime, the controller 540 controls the operation of the pumps 552, 502, 514, 524, 534 according to the heat load amount of the heat exchangers 510, 520, 530 on the demand side. In the embodiment of FIG. 4, the pump 552 for feeding the heat medium to the use side heat exchanger 500 is a constant speed pump. However, if the pump 552 is also a variable speed pump driven by an inverter drive motor, the pump 552 is more suitable. It can be controlled to the circulation amount of the heat medium, which saves energy.

In the embodiment shown in FIG. 4 as well, if the heat exchangers 510, 520, 530 of the demand source are heat exchangers that exchange heat with the atmosphere such as fan coils, the cold water lines 510a, 510b; 520a, 520b; What is necessary is just to provide a ventilation fan instead of 530a, 530b. In addition, the number of booster pumps is not limited to one for each line. When the pipe length is long, the pipe diameter is large, or when there are a large number of bend parts, a plurality of booster pumps cause periodic fluctuations in the heat medium. It becomes possible to give more accurately. That is, when the flow tends to be turbulent, it is preferable to provide a booster pump capable of giving periodic fluctuations.

DESCRIPTION OF SYMBOLS 10 ... District air-conditioning district, 12 ... Road, 14 ... Railway, 16a-16j ... (Use of district air-conditioning and heating) Building, 21 ... Machine building, 23 ... Heat exchange building, 30 ... Piping equipment, 80 ... District air-conditioning system, 100 ... Heat transfer system, 110 ... heat pump chiller, 111 ... heat source side heat exchanger, 112 ... use side heat exchanger, 113 ... pressure reducing means (expansion valve), 114 ... four-way valve, 115 ... compressor, 115b ... drive motor, 116a to 116d ... switching valve, 117 ... cooling tower, 120 ... turbo refrigerator, 121 ... condenser, 122 ... evaporator, 123 ... decompression means (expansion valve), 125 ... turbo refrigerator main body, 125b ... drive motor, 127 ... Cooling tower, 131a to 131d ... Switching valve, 132 ... Cooling tower, 140 ... (Double effect) absorption chiller / heater, 141 ... High temperature regenerator, 142 ... Low temperature regenerator 143 ... Condenser, 144 ... Absorber, 145 ... Evaporator, 150 ... Boiler, 151 ... Steam / hot water heat exchanger, 152, 153 ... Valve, 155 ... Steam line (forward), 156 ... Steam line (return), 157 ... Hot water line (outward), 158 ... Hot water line (return), 161 to 164 ... Pump, 165 ... Pump, 166 ... Inverter, 167 ... Pump, 168 ... Inverter, 170 ... Cold storage tank, 172 ... Cold water feed line, 174 ... Cool water return line, 181a to 181d ... Pump, 182a to 182d ... Inverter, 211 ... Cooling water line, 212 ... Refrigerant line, 213 ... Cold / hot water line (outward), 214 ... Cool / hot water line (return), 221 ... Cooling Water line, 222 ... refrigerant line, 223 ... cold water line (outward), 224 ... cold water line (return), 231 ... cooling water line 232 ... Cooling water line (return) 233 ... Cold and hot water line (return) 234 ... Cool and hot water line (return) 241 ... Cool water line (outward) 242 ... Hot water line (outward) 243 ... Cold water line (return), 244 ... Hot water line (return), 251 ... Steam line (return), 252 ... Steam line (return), 253 ... Gas line, 255 ... Steam line (return), 256 ... Steam line (return) 261 ... Hot water line (outward) 262 ... Cold water line (outward) 263 ... Hot water line (return) 264 ... Cold water line (return) 331 ... Hot water branch line (outward) 332 ... Cold water branch line (outward) 333 ... Hot water branch line (return) 334 ... Cold water branch line (return), 391 ... Hot water branch line (outward), 392 ... Cold water branch line (outward), 393 ... Hot water branch Line (return), 394 ... Cold water branch line (return), 400 ... Usage side heat exchanger, 400a, 400bd ... Cold water line, 400c, 400d ... Refrigerant line, 402 ... Pump, 404 ... Inverter drive motor, 404b ... Signal line 406 ... sensor 406a ... signal line 410 ... heat exchanger 410a, 410b ... cold water line 412 ... sensor 412a ... signal line 414 ... pump 416 ... inverter drive motor 416b ... signal line 420 ... heat Exchanger, 420a to 420d ... chilled water line, 422 ... sensor, 422a ... signal line, 424 ... pump, 426 ... inverter drive motor, 426b ... signal line, 430 ... heat exchanger, 430a-430d ... cold water line, 432 ... sensor 432a ... signal line, 434 ... pump, 436 ... inverter drive motor, 43 b ... signal line, 440 ... control device, 500 ... use side heat exchanger, 500a, 400b ... cold water line, 500c, 500d ... refrigerant line, 502 ... pump, 504 ... inverter drive motor, 504b ... signal line, 506 ... sensor 506a ... Signal line, 510 ... Heat exchanger, 510a to 510d ... Cold water line, 512 ... Sensor, 512a ... Signal line, 514 ... Pump, 516 ... Inverter drive motor, 516b ... Signal line, 520 ... Heat exchanger, 520a 520d ... Cold water line 522 ... Sensor 522a ... Signal line 524 ... Pump 526 ... Inverter drive motor 526b ... Signal line 530 ... Heat exchanger 530a-530d ... Cold water line 532 ... Sensor 532a ... Signal Line, 534 ... Pump, 536 ... Inverter drive motor, 536b ... Signal line, 54 ... controller, 550 ... cold storage tank, 550a, 550b ... cold water line, 552 ... pump.

Claims (7)

1. In a heat transfer system for transferring a heat medium whose temperature has been lowered by heat exchange with a chiller or a use side heat exchanger of a refrigerator to a heat exchanger of a demand source,
   The heat medium has a latent heat in the temperature range of the use side heat exchanger and includes a cold storage material having a heat capacity larger than that of water, and includes the use side heat exchanger and the heat exchanger of the demand source. A heat transfer system characterized in that pipe resistance reduction means is provided in a line of a heat medium to be connected.
2. The heat transfer system according to claim 1, wherein the pipe resistance reducing means includes a rotation speed variable pump arranged in the heat medium line and capable of providing a periodic flow velocity fluctuation.
3. 3. The heat according to claim 2, wherein a plurality of the pipe resistance reducing means are arranged in the line of the heat medium, and a control device is provided that synchronizes a flow rate fluctuation period of the plurality of arranged pipe resistance reducing means. Conveying system.
4. 3. A control device is provided, wherein a plurality of the pipe resistance reducing means are arranged in the line of the heat medium, and a flow rate fluctuation period of the plurality of arranged pipe resistance reducing means is changed depending on a pipe diameter. 3. The heat transfer system according to 3.
5. The heat transfer system according to any one of claims 1 to 4, wherein a cycle of the flow velocity fluctuation is 10 seconds or more.
6. The heat transfer system according to any one of claims 1 to 5, wherein the cold storage material is a liquid obtained by mixing about 10 to 40% of an organic substance such as paraffin wax with water.
7. The heat transfer system according to claim 6, wherein the cold storage material is a liquid obtained by mixing about 10 to 40% of an organic substance such as paraffin wax in water, and is configured in a microcapsule state.

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