JP2007192432A - Hot water storage system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide technology capable of achieving high COP in a hot water storage system capable of storing hot water of high temperature in a hot water storage tank. <P>SOLUTION: This hot water storage system comprises the hot water storage tank, a water flow channel connecting an upper portion of the hot water storage tank from a bottom portion of the hot water storage tank at the outside of the hot water storage tank, a means for circulating the water from the bottom portion of the hot water storage tank to the upper portion of the hot water storage tank through the water flow channel, a compression type heat pump, and an absorption type heat pump. When a temperature of the water flowing into the water flow channel from the hot water storage tank is low, heat is absorbed from the atmospheric air by using only the compression type heat pump to heat the water in the water flow channel. When the temperature of water flowing into the water flow channel from the hot water storage tank is high, heat is absorbed from the atmospheric air by using the compression type heat pump to be used as a heat source of the absorption type heat pump, and the water flow channel is heated by using the absorption type heat pump. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hot water storage system that heats water and stores hot water in a hot water storage tank. Specifically, high COP (Coefficient of Performance) is realized by switching between heating using only a compression heat pump and heating using an absorption heat pump and a compression heat pump in accordance with the temperature of the water to be heated. It relates to a hot water storage system.

  Conventionally, a system that heats water using a heat pump and stores hot water in a hot water tank is known. Various types of heat pumps are used. Typically, a compression heat pump and an absorption heat pump are known.

  The compression heat pump includes a compressor that compresses the working fluid, a cooling unit that cools the compressed working fluid, an expander that expands the cooled working fluid, and a heating unit that heats the expanded working fluid. Yes. The working fluid is compressed by the compressor, cooled by the cooling means, expanded by the expander, and repeated in a cycle heated by the heating means.

  Using the compression heat pump, water can be heated by causing the cooling means to exchange heat with water and the working fluid, and the heating means to exchange heat between the atmosphere and the working fluid. In this case, the working fluid expanded by the expander is at a lower temperature than the atmosphere, and the working fluid is heated by heat exchange with the atmosphere. Further, the working fluid compressed by the compressor is at a high temperature, and the working fluid is cooled by heat exchange with water. By flowing the heated water into the hot water tank, hot water can be stored in the hot water tank. The hot water heated to the desired temperature can be stored in the hot water tank by repeating a series of processes in which water is pumped from the hot water tank, heated by a compression heat pump, and the heated water is returned to the hot water tank. .

  In the hot water storage system using the compression heat pump described above, water is heated using heat absorbed from the atmosphere, so it is possible to store a large amount of hot water in the hot water storage tank with low energy consumption, and a high COP. Can be realized.

  On the other hand, an absorption heat pump heats a solution diluted with a solvent to separate it into a solvent vapor and a concentrated solution, a condenser that cools and condenses the separated solvent vapor, and heats the condensed solvent. And an evaporator that evaporates and absorbs the evaporated solvent in a concentrated solution for dilution, and cools the diluted solution. The solvent evaporates in the evaporator, is absorbed in the concentrated solution by the absorber, is evaporated and separated from the solution in the regenerator, and is condensed in the condenser. The solution is diluted by absorbing the solvent in the absorber and evaporating and concentrating the solvent in the regenerator.

  In the regenerator, the solvent in the solution absorbs the heat of evaporation and evaporates. The evaporated solvent is condensed by releasing heat of condensation in the condenser. Therefore, the working fluid can be heated by the condenser using the heat applied by the regenerator. The heated working fluid can be used as a means for heating water for hot water storage.

  In the evaporator, the solvent absorbs the heat of evaporation and evaporates. The evaporated solvent is absorbed into the concentrated solution by the absorber and releases heat of absorption. Therefore, the working fluid can be heated by the absorber using the heat applied by the evaporator. The heated working fluid can be used as a means for heating water for hot water storage.

  Although the absorption heat pump is inferior to the compression heat pump in COP, the temperature of the working fluid can be adjusted by adjusting the combination of the solute and the solvent, the concentration of the solution, and the pressure of evaporation and condensation of the solvent. Is possible.

For example, Patent Documents 1 to 5 describe hybrid heat pump systems that use the above-described compression heat pump and absorption heat pump in combination.
JP 2004-108731 A JP 2004-116800 A JP 2004-116806 A JP-A-2005-77036 JP-A-2005-77037

  In a hot water storage system using a compression heat pump, when trying to heat water to a high temperature, there is a problem that an excessive load is applied to the compressor and COP is lowered. For example, compared with the case where water is heated from 20 ° C. to 30 ° C., the case where the water is heated from 40 ° C. to 50 ° C. greatly reduces the COP. Therefore, in a hot water storage system using a compression heat pump, water is heated to, for example, about 40 ° C., and hot water that is not so hot at about 40 ° C. is stored in a large hot water storage tank. If you want to supply hot water that is lower than the temperature of the hot water stored (for example, hot water of about 30 ° C), mix the hot water in the hot water tank with tap water and then supply the hot water to the desired temperature. Hot water can be supplied. If you want to supply hot water at a higher temperature (for example, hot water of about 60 ° C.), heat the hot water drawn from the hot water storage tank with an auxiliary heat source machine such as a burner and raise the temperature to the desired temperature before supplying hot water. Do. If the auxiliary heat source device is used in this way, heat loss increases and the thermal efficiency of the system decreases.

  As a system that can supply high-temperature hot water without using an auxiliary heat source device, a system that uses a compression heat pump and an absorption heat pump in combination can be considered. By using a compression heat pump and an absorption heat pump in combination, water can be heated to a high temperature without reducing thermal efficiency. If hot water heated to a high temperature (for example, hot water of about 60 ° C.) is stored in a hot water storage tank, high temperature hot water can be supplied without using an auxiliary heat source machine. If you want to supply hot water at a temperature lower than the temperature of the hot water stored in the hot water, you can supply hot water adjusted to the desired temperature by mixing the hot water in the hot water tank with hot water and then supplying hot water. .

  However, when heating low-temperature water such as tap water to a high temperature, the water is heated using only a compression heat pump rather than using a compression heat pump and an absorption heat pump as long as the water temperature is not so high. The thermal efficiency is higher. For example, when water is heated from 20 ° C. to 30 ° C., the COP is higher when only the compression heat pump is used than when the compression heat pump and the absorption heat pump are used in combination.

  As described above, a hot water storage system that heats water using only a compression heat pump and a hot water storage system that uses a compression heat pump and an absorption heat pump together have advantages and disadvantages. If both can be properly used, high-temperature hot water can be stored in a hot water storage tank with a high COP.

  The present invention provides a technology capable of realizing a high COP in a hot water storage system capable of storing high-temperature hot water in a hot water storage tank.

  The present invention is embodied as a hot water storage system in which hot water is stored in a hot water storage tank using a compression heat pump and an absorption heat pump in combination. The compression heat pump includes a compressor that compresses a first working fluid, an expander that expands the first working fluid, and a heat absorber that heats the first working fluid by exchanging heat between the first working fluid and the atmosphere. It has. The absorption heat pump includes a regenerator that heats a solution to separate it into a solvent vapor and a concentrated solution, a condenser that cools and condenses the separated solvent vapor, and heat between the condensed solvent and the first working fluid. An evaporator that heats and evaporates the solvent, and an absorption that absorbs the solvent vapor into the concentrated solution, dilutes the concentrated solution, and heat-exchanges between the diluted solution and the second working fluid to cool the solution And a means for refluxing the cooled solution to the regenerator. The hot water storage system includes a hot water storage tank, a water flow path connecting the bottom of the hot water storage tank to the upper part of the hot water storage tank via the first heat exchanger and the second heat exchanger, and the water at the bottom of the hot water storage tank through the water flow path. Drive means for refluxing to the upper part of the tank, first circulation means for circulating the first working fluid in a first circulation path for circulating the compressor, the first heat exchanger, the expander, and the heat absorber in order, and the first operation A second circulation means for circulating the fluid in the order of the compressor, the evaporator, the expander, and the heat absorber; and the second circulation means for circulating the second working fluid in the order of the absorber and the second heat exchanger. Third circulation means for circulating the three circulation paths is provided. In the hot water storage system, when the temperature of the water flowing into the water flow path from the bottom of the hot water tank does not reach a predetermined temperature, the compression heat pump and the first circulation means are operated to heat the water with the first heat exchanger. To do. The hot water storage system operates the compression heat pump, the absorption heat pump, the second circulation means, and the third circulation means when the temperature of the water flowing into the water flow path from the bottom of the hot water tank exceeds the predetermined temperature, Water is heated in the second heat exchanger.

  In the above hot water storage system, water is pumped from the bottom of the hot water tank by the driving means, the pumped water is heated by the first heat exchanger or the second heat exchanger, and the heated water is returned to the upper part of the hot water tank. . By repeating such circulating heating, hot water having a desired temperature can be stored in the hot water tank. The hot water stored in the hot water storage tank can be used for hot water supply or heating, for example.

  The hot water storage system includes a compression heat pump and an absorption heat pump as a heat source for heating water drawn from the bottom of the hot water tank. The above hot water storage system may heat water using only a compression heat pump depending on the temperature of water flowing into the water flow path from the bottom of the hot water tank, or it may use both a compression heat pump and an absorption heat pump. Heating water may also be heated.

  When the temperature of the water flowing into the water channel from the bottom of the hot water tank is less than the predetermined temperature, that is, when the temperature of the water flowing into the water channel from the bottom of the hot water tank is not so high, heat is released from the atmosphere by the compression heat pump. It absorbs and heats the water flowing through the water channel using the absorbed heat. In such a case, the first working fluid of the compression heat pump can heat the water even if the temperature is not so high, so that a high COP is realized without applying an excessive load to the compressor. Water can be heated while.

  When the temperature of the water flowing into the water channel from the bottom of the hot water tank exceeds a predetermined temperature, that is, when the temperature of the water flowing into the water channel from the bottom of the hot water tank is high, the heat from the atmosphere is absorbed by the compression heat pump. The absorbed heat is used as a heat source for the evaporator of the absorption heat pump. The absorption heat pump uses the heat applied from the first working fluid in the evaporator to heat the second working fluid in the absorber. The heated second working fluid heats the water flowing through the water flow path. In the absorption heat pump, even when the first working fluid that is not so hot is used as a heat source of the evaporator, the second working fluid can be heated to a high temperature by the absorber. Therefore, high-temperature water flowing through the water flow path can be heated without applying an excessive load to the compressor of the compression heat pump.

  In addition, the 1st working fluid and the 2nd working fluid may use the same kind of fluid.

  In addition, the temperature of the water flowing into the water channel from the bottom of the hot water tank can be measured by various methods. For example, a temperature sensor that measures the water temperature inside the hot water storage tank, which is provided near the bottom of the hot water storage tank, can also be measured. Or it is a temperature sensor which measures the water temperature inside a water flow path, Comprising: It can also measure using what was provided in the upstream rather than any of a 1st heat exchanger and a 2nd heat exchanger.

  In the above hot water storage system, the condenser of the absorption heat pump includes a heat exchanger that cools the solvent vapor by exchanging heat between the separated solvent vapor and the second working fluid, and the third circulation means includes: The second working fluid is preferably circulated in the order of the absorber, the condenser, and the second heat exchanger.

  With the above configuration, when heating the high-temperature water flowing through the water flow path, the heat applied to the second working fluid in the absorber of the absorption heat pump is added to the second working fluid in the condenser. Both heats can be used to heat the water. The temperature rise range until the water pumped out from the bottom of the hot water tank returns to the upper part of the hot water tank increases, and hot hot water can be stored in the hot water tank in a short period of time.

  According to the present invention, a high COP can be realized in a hot water storage system capable of storing high-temperature hot water in a hot water storage tank.

The main features of the embodiments described below are listed first.
(Mode 1) The first working fluid of the compression heat pump is a compressive fluid such as Freon or carbon dioxide.
(Mode 2) The absorption heat pump solution is a lithium salt solution such as an aqueous lithium bromide solution or an aqueous ammonia solution.
(Mode 3) The evaporator and the absorber of the absorption heat pump are provided inside a common tank.
(Mode 4) When the absorption heat pump is used in a high temperature range, a lithium salt solution is used as the solution. In this case, water becomes a solvent. The evaporator and the absorber are maintained at a low pressure inside.
(Mode 5) When the absorption heat pump is used in a low temperature range, an aqueous ammonia solution is used as the solution. In this case, ammonia is the solvent. The evaporator and the absorber are maintained at a high pressure inside.

  A system 100 embodying the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 to 5, the system 100 mainly includes an air conditioner 102, a hot water tank 104, an absorption heat pump 106, a compression heat pump 108, a controller 300, and a remote controller 302. The operation mode of the system 100 is controlled by the controller 300, and a cooling operation, a heating operation, a hot water storage operation, and the like can be performed.

  The remote control 302 can communicate with the controller 300. The user of the system 100 can set the operating state of the system 100, the set temperature during cooling or heating operation, the hot water storage temperature in the hot water storage tank, the hot water supply temperature, etc. by operating the remote controller 302. it can. The content set by the user on the remote control 302 is transmitted to the controller 300. The controller 300 controls the operation of the system 100 by controlling operations of various valves, pumps, compressors, heating sources, and the like constituting the system 100 based on the contents set by the user.

(1) Cooling operation, heating operation FIG. 1 shows a state during cooling operation of the system 100 of the present embodiment. The system 100 starts the cooling operation when the user sets the start of the cooling operation on the remote controller 302.

  The air conditioner 102 is an air conditioner that uses water as a working fluid. The air conditioner 102 can communicate with the controller 300, and performs either a cooling operation or a heating operation in accordance with an instruction from the controller 300. In the cooling operation, the working fluid is cooled by the absorption heat pump 106, and the cooling operation is performed using the cooled working fluid. In the heating operation, the working fluid is heated by the absorption heat pump 106, and the heating operation is performed using the heated working fluid.

  The absorption heat pump 106 uses a lithium salt solution such as an aqueous lithium bromide solution as a working fluid. The absorption heat pump 106 mainly includes a high temperature regenerator 110, a separator 122, a low temperature regenerator 112, a condenser 114, an evaporator 116, and an absorber 118. The low-temperature regenerator 112, the condenser 114, the evaporator 116, and the absorber 118 are formed in a negative pressure tank 120 whose interior is kept at a low pressure.

  The high-temperature regenerator 110 includes a high-temperature regenerative heat exchanger 124 through which a low-concentration solution (hereinafter referred to as a dilute liquid) passes, and a heating source (burner) that heats the dilute liquid that passes through the high-temperature regenerative heat exchanger 124 with combustion gas. 126 is provided. The dilute liquid in the dilute liquid flow path 130 is driven by the pump 128 to flow into the high temperature regenerator 110 and is supplied to the high temperature regenerative heat exchanger 124. The dilute liquid heated and boiled while passing through the high-temperature regenerative heat exchanger 124 is guided to the separator 122 and separated into water vapor and a concentrated medium-concentration solution (hereinafter referred to as a medium liquid).

  The water vapor and the intermediate liquid separated by the separator 122 are divided and supplied to the low temperature regenerator 112 formed in the upper part of the negative pressure tank 120 through the water vapor channel 132 and the intermediate liquid channel 134, respectively. When supplied to the low-temperature regenerator 112, the intermediate liquid flowing through the intermediate liquid flow path 134 exchanges heat with the dilute liquid flowing through the dilute liquid flow path 130 by the heat exchanger 136. As a result, the intermediate liquid is cooled and supplied to the low temperature regenerator 112, and the dilute liquid is heated and supplied to the high temperature regenerator 110.

  A low-temperature regenerative heat exchanger 138 is provided in the low-temperature regenerator 112, and steam that flows into the low-temperature regenerative heat exchanger 138 from the steam flow path 132 and low-temperature regenerative heat exchanger 138 from the middle liquid flow path 134. Heat exchange is performed with the middle liquid dripped on the surface of the liquid. Through the heat exchange, the water vapor is cooled and the intermediate liquid is heated. The cooled water vapor is condensed into water, led from the low temperature regeneration heat exchanger 138 to the condenser 114, and stored at the bottom of the condenser 114. Condensation heat generated when the water vapor condenses is absorbed by the intermediate liquid, and the intermediate liquid boils again to produce water vapor and a high-concentration solution (hereinafter referred to as a concentrated liquid). Water vapor and concentrated liquid are separated in the low temperature regenerator 112, and the concentrated liquid is stored at the bottom of the low temperature regenerator 112. The water vapor generated from the middle liquid moves into the condenser 114 having a low vapor pressure.

  During the cooling operation, the water vapor in the condenser 114 is guided to the atmospheric heat exchanger 146 cooled by the blower 144 via the water vapor flow path 142 including the valve 140 as shown in FIG. The water vapor is condensed by the atmospheric heat exchanger 146, refluxed to the condenser 114, and stored at the bottom of the condenser 114. The condensation heat at this time is released from the atmospheric heat exchanger 146 to the atmosphere. During heating operation, the valve 140 is closed as shown in FIG. 2, condensed on the surface of the condensation heat exchanger 148 provided in the condenser 114, and stored at the bottom of the condenser 114. The condensation heat at this time is absorbed by the working fluid flowing in the condensation heat exchanger 148.

  Two heat exchangers 150 and 152 are provided in the lower part of the negative pressure tank 120. One of the heat exchangers 150 and 152 functions as a heat exchanger (evaporation heat exchanger) of the evaporator 116 by switching the flow paths of the three-way valves 154 and 156, and the other is a heat exchanger (absorption heat of the absorber 118). Function as an exchange). As shown in FIG. 1, during the cooling operation, the heat exchanger 150 functions as an absorption heat exchanger, and the heat exchanger 152 functions as an evaporation heat exchanger. As shown in FIG. 2, during the heating operation, the heat exchanger 152 functions as an absorption heat exchanger, and the heat exchanger 150 functions as an evaporation heat exchanger. A concentrated liquid supplied from the bottom of the low-temperature regenerator 112 via the concentrated liquid flow path 158 is sprayed from above on the absorption heat exchanger. At this time, the concentrated liquid flowing through the concentrated liquid flow path 158 exchanges heat with the diluted liquid flowing through the diluted liquid flow path 130 by the heat exchanger 162. As a result, the dilute liquid flowing in the dilute flow path 130 is heated and supplied to the heat exchanger 136, and the concentrated liquid flowing in the concentrated liquid flow path 158 is cooled and supplied to the absorber 118. In the evaporative heat exchanger, water supplied from the bottom of the condenser 114 via the water channel 160 is sprayed from above.

  The water sprayed on the evaporative heat exchanger (heat exchanger 152 during the cooling operation shown in FIG. 1) evaporates on the surface of the evaporative heat exchanger to become water vapor, and moves to the absorber 118 having a low vapor pressure. At this time, the vapor generated on the surface of the evaporation heat exchanger removes heat of evaporation from the working fluid flowing in the evaporation heat exchanger, thereby cooling the working fluid. The water vapor that has moved to the absorber 118 is absorbed by the concentrated liquid on the surface of the absorption heat exchanger (the heat exchanger 150 during the cooling operation), and is stored as a diluted liquid at the bottom of the absorber 118. The absorbed heat generated at this time is absorbed by the working fluid flowing in the absorption heat exchanger.

  The concentrated liquid channel 158 and the water channel 160 include three-way valves 154 and 156, respectively. During the cooling operation, the three-way valve 154 switches so that the concentrated liquid flows to the heat exchanger 150 and the three-way valve 156 switches so that the water flows to the heat exchanger 152. During the heating operation, the three-way valve 154 switches so that the concentrated liquid flows to the heat exchanger 152 and the three-way valve 156 switches so that water flows to the heat exchanger 150.

  The high-temperature regenerator 110 includes an exhaust heat recovery heat exchanger 196 that exchanges heat between the combustion gas (combustion exhaust gas) after heating the diluted liquid by heat exchange in the high-temperature regenerative heat exchanger 124 and the working fluid flowing inside. Is provided. By exchanging heat with the working fluid, the combustion exhaust gas is cooled and discharged to the outside of the high temperature regenerator 110. The working fluid flowing inside the exhaust heat recovery heat exchanger 196 is heated by heat exchange with the combustion exhaust gas.

  The compression heat pump 108 uses a compressive fluid such as Freon or carbon dioxide as a working fluid. The compression heat pump 108 includes a compressor 164, an atmospheric heat exchanger 166, and an expansion valve 168. A blower 144 is attached to the atmospheric heat exchanger 166. The compression heat pump 108 includes four-way valves 170, 172, 178 and a three-way valve 184, and switches the working fluid flow path in accordance with an instruction from the controller 300.

  During cooling operation, as shown in FIG. 1, the controller 300 switches the four-way valves 170, 172, 178 and the three-way valve 184, and the working fluid compressed by the compressor 164 becomes the atmospheric heat exchanger 166, the expansion valve 168, A flow path returning to the compressor 164 is formed through the heat exchanger 150 (which functions as an absorption heat exchanger during cooling operation). The working fluid is compressed by the compressor 164 to a high temperature and high pressure, and is cooled and condensed by the blower 144 in the atmospheric heat exchanger 166, and the condensed heat is released to the atmosphere. The condensed working fluid is expanded by the expansion valve 168 to become a low temperature, and is supplied to the heat exchanger 150. The low-temperature working fluid that has flowed into the heat exchanger 150 is heated and evaporated by the absorbed heat generated on the surface of the heat exchanger 150. The evaporated working fluid returns to the compressor 164.

  During the heating operation, as shown in FIG. 2, the controller 300 switches the four-way valves 170, 172, 178, and the three-way valve 184, and the working fluid compressed by the compressor 164 is converted into the heat exchanger 150 (evaporation heat during the heating operation). Functioning as an exchanger), an expansion valve 168, and an atmospheric heat exchanger 166 are passed through in this order to form a flow path returning to the compressor 164. The working fluid is compressed by the compressor 164 to a high temperature and pressure, and is supplied to the heat exchanger 150. The working fluid that has flowed into the heat exchanger 150 is deprived of evaporation heat by water vapor generated on the surface of the heat exchanger 150, cooled, and condensed. The condensed working fluid expands at the expansion valve 168 and becomes low temperature, and is heated by the blower 144 in the atmospheric heat exchanger 166 and evaporated. The evaporated working fluid returns to the compressor 164.

  The flow of the working fluid in the air conditioner 102 will be described. During the cooling operation, the four-way valves 186 and 188 and the three-way valves 190 and 192 are switched as shown in FIG. As a result, a working fluid supplied from the air conditioner 102 by the pump 194 passes through the heat exchanger 152 (functioning as an evaporative heat exchanger during the cooling operation) and returns to the air conditioner 102. The high-temperature working fluid supplied from the air conditioner 102 during the cooling operation is deprived of the evaporation heat by the water vapor generated on the surface of the heat exchanger 152, and returns to the air conditioner 102 at a low temperature.

  During the heating operation, the four-way valves 186 and 188 and the three-way valves 190 and 192 are switched as shown in FIG. As a result, the working fluid supplied from the air conditioner 102 by the pump 194 passes through the exhaust heat recovery heat exchanger 196, the heat exchanger 152 (functioning as an absorption heat exchanger during heating operation), and the condensing heat exchanger 148 in this order. Thus, a flow path returning to the air conditioner 102 is formed. The low temperature working fluid supplied from the air conditioner 102 during the heating operation is heated by the combustion exhaust gas in the exhaust heat recovery heat exchanger 196 of the high temperature regenerator 110, and is heated by the absorbed heat generated on the surface of the heat exchanger 152, It is heated by the condensation heat generated on the surface of the condensation heat exchanger 148 and returns to the air conditioner 102.

  When the air conditioner 102 performs a cooling operation, the system 100 according to the present embodiment performs cooling by releasing the heat absorbed by the air conditioner 102 to the atmosphere using the atmospheric heat exchangers 146 and 166. it can. By using the compression heat pump 108 and the absorption heat pump 106 together, a higher COP can be realized as compared with the case where only the absorption heat pump 106 is used. Further, by using the compression heat pump 108 and the absorption heat pump 106 in combination, the load on the compressor 164 can be reduced as compared with the case where only the compression heat pump 108 is used.

  In the system 100 of the present embodiment, when the air conditioner 102 performs a heating operation, the heat absorbed from the atmosphere by the atmospheric heat exchanger 166 and the combustion gas absorbed by the high temperature regenerative heat exchanger 124 of the high temperature regenerator 110 are absorbed. Heating can be performed using heat and energy applied to the working fluid by the compressor 164. By using the compression heat pump 108 and the absorption heat pump 106 together, a higher COP can be realized as compared with the case where only the absorption heat pump 106 is used. Further, by using the compression heat pump 108 and the absorption heat pump 106 in combination, the load on the compressor 164 can be reduced as compared with the case where only the compression heat pump 108 is used.

  In the hybrid heat pump 100 of the present embodiment, when the air conditioner 102 performs the heating operation, the working fluid for air conditioning is heated by the heat exchanger 196 of the high temperature regenerator 110 using the combustion exhaust gas. Thereby, the heat of the combustion gas of the high temperature regenerator 110 can be effectively utilized, and the COP can be further improved.

(2) Hot Water Storage Operation The hot water storage operation of the system 100 of the present invention will be described with reference to FIGS.
The hot water tank 104 stores hot water therein. Hot water inside the hot water tank 104 forms a temperature stratification, and hot water is stored in the upper part of the hot water tank 104, and low temperature hot water is stored in the lower part. When hot water is supplied, hot hot water is pumped from the upper part of the hot water tank 104, and tap water is supplied from the lower part of the hot water tank 104.
A temperature sensor 306 that measures the water temperature inside the hot water tank 104 is provided near the bottom of the hot water tank 104. The temperature sensor 306 transmits the measured temperature to the controller 300.

  The controller 300 watches the temperature measured by the temperature sensor 306. When the temperature measured by the temperature sensor 306 is less than the hot water storage temperature set by the remote controller 302, the controller 300 starts the hot water storage operation.

  When the hot water storage operation is started, the controller 300 determines whether to perform the first hot water storage operation or the second hot water storage operation according to the temperature measured by the temperature sensor 306. When the temperature measured by the temperature sensor 306 is less than 45 ° C., the controller 300 starts the first hot water storage operation. When the temperature measured by the temperature sensor 306 is 45 ° C. or higher, the controller 300 starts the second hot water storage operation.

(A) First hot water storage operation When the temperature measured by the temperature sensor 306, that is, the water temperature near the bottom of the hot water tank 104 is less than 45 ° C., the system 100 compresses without driving the absorption heat pump 106. Water is heated using only the heat pump 108. The first hot water storage operation will be described with reference to FIG.

When the first hot water storage operation is started, the controller 300 switches the four-way valves 170, 172, 178 and the three-way valve 184 of the compression heat pump 108. Thereby, the working fluid flowing out from the compressor 164 passes through the heat exchanger 200, the expansion valve 168, the heat exchanger 150, and the atmospheric heat exchanger 166 in order, and a flow path returning to the compressor 164 is formed. When the controller 300 drives the compressor 164, the working fluid circulates through the formed flow path.
The controller 300 switches the four-way valve 198. As a result, a flow path is formed from the bottom of the hot water tank 104 to the upper part of the hot water tank 104 via the heat exchanger 200. When the controller 300 drives the pump 204, the water inside the hot water tank 104 circulates through the formed flow path.
During the first hot water storage operation, the absorption heat pump 106 is not operating, and the heat exchanger 150 does not perform heat exchange.

  In the first hot water storage operation, heat exchange is performed between the high-temperature and high-pressure working fluid flowing from the compressor 164 into the heat exchanger 200 and the water pumped from the bottom of the hot water tank 104 to the heat exchanger 200 by driving the pump 204. Is done. By the heat exchange in the heat exchanger 200, the working fluid is cooled and condensed, and the water is heated and heated. The water heated by the heat exchanger 200 returns to the upper part of the hot water tank 104. The working fluid cooled and condensed by the heat exchanger 200 is expanded by the expansion valve 168 and becomes a low temperature. The working fluid that has been expanded by the expansion valve 168 to a low temperature is exchanged with the atmosphere by the atmospheric heat exchanger 166. Due to the heat exchange in the atmospheric heat exchanger 166, the working fluid is heated and evaporated. The working fluid heated and evaporated by the atmospheric heat exchanger 166 flows into the compressor 164.

  By circulating the working fluid as described above, the water pumped out from the bottom of the hot water tank 104 can be heated using the heat absorbed from the atmosphere by the atmospheric heat exchanger 166. By circulatingly heating the water in the hot water tank 104 as described above, the water in the hot water tank 104 gradually increases in temperature.

  During the first hot water storage operation, the controller 300 watches the water temperature measured by the temperature sensor 304. The water temperature measured by the temperature sensor 304 indicates the temperature of water pumped from the bottom of the hot water tank 104. When the water temperature measured by the temperature sensor 304 becomes 45 ° C. or higher, the controller 300 shifts the process to the second hot water storage operation described later. When the water temperature measured by the temperature sensor 304 is less than 45 ° C., the controller 300 continues the first hot water storage operation.

  During the first hot water storage operation, the temperature of the water flowing into the heat exchanger 200 is less than 45 ° C. Therefore, it is not necessary to raise the temperature of the working fluid supplied to the heat exchanger 200 to a very high temperature, and energy consumption in the compressor 164 is low. The compression heat pump 108 can be operated at a high COP.

(B) Second Hot Water Storage Operation When the temperature measured by the temperature sensor 306 is 45 ° C. or higher, or when the temperature measured by the temperature sensor 304 is 45 ° C. or higher, the system 100 uses the compression heat pump 108 and the absorption heat pump 106. Heat the water together. The second hot water storage operation will be described with reference to FIG.

When the second hot water storage operation is started, the controller 300 switches the four-way valves 170, 172, 178 and the three-way valve 184 of the compression heat pump 108. As a result, a working fluid flowing out from the compressor 164 passes through the heat exchanger 150, the expansion valve 168, and the atmospheric heat exchanger 166 in order, and a flow path returning to the compressor 164 is formed. When the controller 300 drives the compressor 164, the working fluid circulates through the formed flow path.
The controller 300 switches the three-way valves 154 and 156 of the absorption heat pump 106. Thereby, the heat exchanger 150 functions as an evaporating heat exchanger, and the heat exchanger 152 functions as an absorption heat exchanger. The controller 300 drives the pump 128 and starts the combustion of the heat source 126, so that a series of cycles in the absorption heat pump 106 proceeds.
The controller 300 switches the four-way valves 186 and 188 and the three-way valves 190 and 192. Thus, the working fluid flowing out from the pump 206 passes through the exhaust heat recovery heat exchanger 196, the heat exchanger 152, the condensing heat exchanger 148, and the heat exchanger 202 in this order, and the working fluid flow path returns to the pump 206. Is formed. When the controller 300 drives the pump 206, the working fluid circulates through the formed flow path.
Furthermore, the controller 300 switches the four-way valve 198. As a result, a flow path is formed from the bottom of the hot water tank 104 to the upper part of the hot water tank 104 via the heat exchangers 200 and 202. When the controller 300 drives the pump 204, the water inside the hot water tank 104 circulates through the formed flow path.
In the second hot water storage operation, the working fluid of the compression heat pump 108 does not flow through the heat exchanger 200 and heat exchange in the heat exchanger 200 is not performed.

  In the second hot water storage operation, the working fluid flowing out from the heat exchanger 202 by driving the pump 206 is heated by the exhaust heat recovery heat exchanger 196. The heated working fluid is heated by the absorbed heat generated on the surface of the heat exchanger 152 in the heat exchanger 152 (corresponding to the absorption heat exchanger). The heated working fluid is heated by the condensation heat generated on the surface of the condensation heat exchanger 148 in the condensation heat exchanger 148. The exhaust fluid of the combustion exhaust gas from the high temperature regenerator 110, the absorption heat from the absorber 118, and the working fluid heated by the condensation heat from the condenser 114 are returned to the heat exchanger 202, and are pumped from the lower part of the hot water tank 104 by the pump 204. Heat the pumped water. The heated water returns to the upper part of the hot water tank 104.

  In the second hot water storage operation, the working fluid that has been compressed by the compressor 164 to a high temperature and high pressure flows into the heat exchanger 150 (corresponding to an evaporating heat exchanger). The working fluid that has flowed into the heat exchanger 150 is deprived of evaporation heat by water vapor generated on the surface of the heat exchanger 150, cooled, and condensed. The condensed working fluid expands at the expansion valve 168 and becomes low temperature, and is heated by the blower 144 in the atmospheric heat exchanger 166 and evaporated. The evaporated working fluid returns to the compressor 164.

  When the compression heat pump 108 is driven, water is evaporated by the evaporation heat exchanger of the absorption heat pump 106 using the heat absorbed by the atmospheric heat exchanger 166. When the absorption heat pump 106 is driven, the working fluid flowing through the heat exchanger 202 is recovered from the heat recovered from the combustion exhaust gas of the high-temperature regenerator 110, the absorption heat in the absorption heat exchanger, and the condensation in the condensation heat exchanger 148. Heated by heat. The water pumped out of the hot water storage tank 104 is heated by heat exchange with the heated working fluid. As the water in the hot water tank 104 circulates as described above, the temperature of the water in the hot water tank 104 gradually increases.

  During the second hot water storage operation, the controller 300 watches the water temperature measured by the temperature sensor 304. The water temperature measured by the temperature sensor 304 indicates the temperature of water pumped from the bottom of the hot water tank 104. When the water temperature measured by the temperature sensor 304 is 60 ° C. or higher, the controller 300 determines that no more hot water storage is necessary and ends the hot water storage operation.

  During the second hot water storage operation, the temperature of the water flowing into the heat exchanger 202 is in the range of 45 ° C to 60 ° C. Therefore, the temperature of the working fluid supplied to the heat exchanger 202 needs to be high. In this embodiment, heat is supplied to the evaporator 116 of the absorption heat pump 106 using the compression heat pump 108, and is supplied to the heat exchanger 202 using the absorber 118 and the condenser 114 of the absorption heat pump 106. The working fluid is heated. In such a configuration, it is not necessary to raise the temperature of the working fluid of the compression heat pump 108 to a high temperature. Therefore, since the compression heat pump 108 can be operated with a high COP, the thermal efficiency of the entire system can be increased.

  In the system 100 of the present embodiment, when hot water is stored in the hot water storage tank 104, the first hot water storage operation and the second hot water storage operation are switched according to the temperature of the water pumped from the bottom of the hot water storage tank 104. While the water pumped out of the hot water storage tank 104 is low in temperature, the first hot water storage operation in which the water is heated using only the compression heat pump 108 is performed. A second hot water storage operation is performed in which the heat pump 108 and the absorption heat pump 106 are used together to heat water. Since an excessive load is not applied to the compressor 164 of the compression heat pump 108, the thermal efficiency of the entire system can be increased.

(3) Cooling / Hot Water Storage Operation The system 100 according to the present embodiment can start a hot water storage operation while performing a cooling operation, and can perform a cooling operation and a hot water storage operation in parallel. The cooling operation can be started while the cooling operation and the hot water storage operation are performed in parallel. Hereinafter, a mode in which the cooling operation and the hot water storage operation are performed in parallel is described as the cooling / hot water storage operation. The cooling / hot water storage operation will be described with reference to FIG.

When the cooling / hot water storage operation is started, the controller 300 switches the four-way valve 198. As a result, a flow path is formed from the bottom of the hot water tank 104 to the upper part of the hot water tank 104 via the heat exchangers 200 and 202. When the controller 300 drives the pump 204, the water inside the hot water tank 104 circulates through the formed flow path.
The controller 300 switches the four-way valves 170, 172, 178 and the three-way valve 184 of the compression heat pump 108. Thereby, the working fluid flowing out from the compressor 164 passes through the heat exchanger 200, the expansion valve 168, and the heat exchanger 150 in this order, and a flow path is formed that returns to the compressor 164.
The controller 300 switches the three-way valves 154 and 156 of the absorption heat pump 106. Thereby, the heat exchanger 150 functions as an absorption heat exchanger, and the heat exchanger 152 functions as an evaporating heat exchanger. When the controller 300 drives the pump 128 and starts the combustion of the heat source 126, a series of cycles in the absorption heat pump proceeds.
Further, the controller 300 switches the four-way valve 186 and the three-way valves 190 and 192. Thus, a flow path is formed in which the working fluid flowing out from the pump 194 returns to the pump 194 through the air conditioner 102 and the heat exchanger 152 in this order. When the controller 300 drives the pump 194, the working fluid circulates through the formed flow path. The controller 300 switches the four-way valve 188. As a result, a flow path is formed in which the working fluid flowing out from the pump 206 returns to the pump 206 via the condensation heat exchanger 148 and the heat exchanger 202 in this order. When the controller 300 drives the pump 206, the working fluid circulates through the formed flow path.

In the cooling / hot water storage operation, the water in the hot water storage tank 104 is heated by the operation of both the absorption heat pump 106 and the compression heat pump 108. In the cooling / hot water storage operation, the absorption heat pump 106 performs substantially the same operation as in the cooling operation, but instead of cooling the water vapor in the condenser 114 by heat exchange with the atmosphere in the atmospheric heat exchanger 146, evaporation is performed. Cooling is performed by exchanging heat with the working fluid flowing in the heat exchanger 148. The working fluid of the compression heat pump 108 is compressed to a high temperature by the compressor 164, is cooled and condensed in the heat exchanger 200, and releases condensation heat. The condensed working fluid is expanded by the expansion valve 168 to become a low temperature, and is supplied to the heat exchanger 150. The low-temperature working fluid is heated and evaporated by the absorbed heat generated on the surface of the heat exchanger 150. The evaporated working fluid is heated by the exhaust gas from the high-temperature regenerator 110 in the exhaust heat recovery heat exchanger 185 and returns to the compressor 164. In the heat exchanger 200, heat is exchanged between the water pumped from the bottom of the hot water storage tank 104 by driving the pump 204 and the working fluid that has been compressed by the compressor 164 to a high temperature, and the water is heated. Supplied to the heat exchanger 202.
In the cooling / hot water storage operation, the working fluid returns from the heat exchanger 202 to the heat exchanger 202 via the condensation heat exchanger 148 by driving the pump 206. The working fluid is heated to a high temperature in the condensation heat exchanger 148 by the condensation heat generated on the surface of the condensation heat exchanger 148. The high-temperature working fluid exchanges heat with water returning to the hot water tank 104 in the heat exchanger 202. Water heated to a high temperature by the heat exchanger 202 returns to the upper part of the hot water tank 104.
As described above, the system 100 of the present embodiment can perform the cooling operation and the hot water storage operation in parallel.

  As described above, the system 100 of the present embodiment is a hot water storage system that stores hot water in the hot water storage tank 104 by using the compression heat pump 108 and the absorption heat pump 106 together. The compression heat pump 108 includes a compressor 164 that compresses the first working fluid, an expansion valve 168 that expands the first working fluid, and an atmosphere that heats the first working fluid by exchanging heat between the first working fluid and the atmosphere. A heat exchanger 166 is provided. The absorption heat pump 106 includes a high-temperature regenerator 110 and a low-temperature regenerator 112 that heat the solution to separate it into a solvent vapor and a concentrated solution, a condenser 114 that cools and condenses the separated solvent vapor, and a condensed solvent. An evaporator 116 that heat-exchanges between the first working fluid to heat and evaporate the solvent, and absorbs the solvent vapor into the concentrated solution to dilute the concentrated solution, and between the diluted solution and the second working fluid An absorber 118 that cools the solution by exchanging heat and means for refluxing the cooled solution to the high temperature regenerator 110 and the low temperature regenerator 112 are provided. The system 100 includes a hot water storage tank 104, a water flow path connecting the bottom of the hot water storage tank 104 to the upper part of the hot water storage tank 104 through the heat exchanger 200 and the heat exchanger 202, and water at the bottom of the hot water storage tank 104. Then, a pump 204 that recirculates to the upper part of the hot water storage tank 104, and a first circulation that circulates the first working fluid in a first circulation path that circulates the compressor 164, the heat exchanger 200, the expansion valve 168, and the atmospheric heat exchanger 166 in this order. Means, a second circulation means for circulating the first working fluid in the order of the compressor 164, the evaporator 116, the expansion valve 168, and the atmospheric heat exchanger 166, and the second working fluid for the absorber. A third circulation means for circulating a third circulation path that circulates in the order of 118 and the heat exchanger 202 is provided. When the temperature of the water flowing into the water flow path from the bottom of the hot water storage tank 104 does not reach a predetermined temperature, the system 100 operates the compression heat pump 108 and the first circulation means to heat the water with the heat exchanger 200. To do. The system 100 operates the compression heat pump 108, the absorption heat pump 106, the second circulation means, and the third circulation means when the temperature of the water flowing into the water flow path from the bottom of the hot water tank 104 exceeds the predetermined temperature. Then, water is heated by the heat exchanger 202.

  The system 100 also includes a condensation heat exchanger 148 in which the condenser 114 cools the solvent vapor by exchanging heat between the separated solvent vapor and the second working fluid, and the third circulation means includes a first circulation means. Two working fluids are circulated in the order of the absorber 118, the condenser 114, and the heat exchanger 202.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
In addition, the technical elements described in the present specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

FIG. 1 is a diagram showing a state of the system 100 during cooling operation. FIG. 2 is a diagram illustrating a state of the system 100 during heating operation. FIG. 3 is a diagram showing a state of the system 100 during the first hot water storage operation. FIG. 4 is a diagram showing a state of the system 100 during the second hot water storage operation. FIG. 5 is a diagram illustrating a state of the system 100 during the cooling / hot water storage operation.

Explanation of symbols

100: system 102: air conditioner 104: hot water storage tank 106: absorption heat pump 108: compression heat pump 110: high temperature regenerator 112: low temperature regenerator 114: condenser 116: evaporator 118: absorber 120: negative pressure tank 122: Separator 124: High temperature regenerative heat exchanger 126: Heat source 128, 194, 204, 206: Pump 130: Dilute liquid flow path 132, 142: Water vapor flow path 134: Middle liquid flow path 136, 150, 152, 162, 200 202: Heat exchanger 138: Low temperature regeneration heat exchanger 140: Valve 144: Blower 146, 166: Atmospheric heat exchanger 148: Condensation heat exchanger 154, 156, 184, 190, 192: Three-way valve 158: Concentrated liquid flow Channel 160: Water channel 164: Compressor 168: Expansion valves 170, 172, 178, 186, 188, 198: Four-way valve 19 : Heat recovery heat exchanger 300: controller 302: remote control 304, 306: temperature sensor

Claims (2)

A hot water storage system that uses a compression heat pump and an absorption heat pump together to store hot water in a hot water tank,
The compression heat pump
A compressor for compressing the first working fluid;
An inflator for inflating the first working fluid;
A heat absorber for heating the first working fluid by exchanging heat between the first working fluid and the atmosphere;
Absorption heat pump
A regenerator that heats the solution to separate it into solvent vapor and concentrated solution;
A condenser for cooling and condensing the separated solvent vapor;
An evaporator that heats and evaporates the solvent by exchanging heat between the condensed solvent and the first working fluid;
An absorber that absorbs the solvent vapor into the concentrated solution to dilute the concentrated solution and heat exchange between the diluted solution and the second working fluid to cool the solution;
Means for refluxing the cooled solution to the regenerator,
The hot water storage system
A hot water tank,
A water flow path connecting the bottom of the hot water tank to the upper part of the hot water tank via the first heat exchanger and the second heat exchanger;
Driving means for returning water at the bottom of the hot water tank to the upper part of the hot water tank through the water flow path;
A first circulation means for circulating a first working fluid through a first circulation path that circulates in order of a compressor, a first heat exchanger, an expander, and a heat absorber;
Second circulation means for circulating a first working fluid through a second circulation path for circulating the first working fluid in the order of the compressor, the evaporator, the expander, and the heat absorber;
A third circulating means for circulating a third working path for circulating the second working fluid in the order of the absorber and the second heat exchanger;
When the temperature of the water flowing into the water flow path from the bottom of the hot water tank is less than the predetermined temperature, the compression heat pump and the first circulation means are operated to heat the water with the first heat exchanger,
When the temperature of the water flowing into the water flow path from the bottom of the hot water tank exceeds the predetermined temperature, the second heat exchanger is operated by operating the compression heat pump, the absorption heat pump, the second circulation means, and the third circulation means. Hot water storage system characterized by heating water with water. The condenser includes a heat exchanger that cools the solvent vapor by exchanging heat between the separated solvent vapor and the second working fluid;
The hot water storage system according to claim 1, wherein the third circulation means circulates the second working fluid in the order of an absorber, a condenser, and a second heat exchanger.

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