JP2006078111A - Large-capacity hot water supply system and its operation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a large-capacity hot water supply system capable of uniformizing the load of an electric water heater in supplying a large capacity of hot water to facilitate control works of hot water supply and additional heating, and flexibly responding to even a case that a hot water supply quantity is over a hot water storage quantity of a hot water storage tank to enable continuous hot water supply and its operation method. <P>SOLUTION: A plurality of hot water storage type electric water heaters are combined to constitute a hot water supply system. Each hot water storage type electric water heater comprises a heating means H heating hot water, a plurality of hot water storage tanks T, and a hot water supply passage P for circulating hot water. The hot water supply passages P to the plurality of hot water storage type electric water heaters are alternately opened and closed through an electric valve M installed to each hot water supply passage P. A serial connecting pipe Q is arranged in each hot water storage tank T, and all the hot water storage tanks T in one hot water storage type electric water heater are laid in a serial state to supply hot water by a water supply pressure. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a large-capacity hot water supply system that can supply large-capacity continuous hot water using a hot-water storage type electric water heater and can make the load of the electric water heater uniform, and an operation method thereof.

  As a system that uses a plurality of hot water storage type electric water heaters in combination, for example, there are systems disclosed in Patent Documents 1 to 3.

  The hot water supply apparatus described in Patent Document 1 is designed to improve comfortability while suppressing an increase in cost, and a plurality of hot water heated by the heating means are arranged in a line substantially in parallel. It is stored in a hot water storage tank. This makes it possible to reduce the diameter of each hot water storage tank, for example, when the hot water storage capacity is equivalent to that of a conventional hot water storage tank, for example, a passage space when installed in an alley, a veranda, etc. Because the space where people can act is widened, the comfortability can be improved than before, and the heating means, water supply piping, and hot water supply piping are shared for each hot water storage tank, so that the cost increase can be suppressed. It is.

  The hot water supply apparatus described in Patent Document 2 is a hot water supply apparatus devised so as to be able to supply hot water that has reached a set temperature more quickly. In the third embodiment of the hot water supply apparatus, a plurality of hot water storage tanks are provided in parallel, and an open / close valve is provided at the water supply port of each hot water storage tank. By switching the open / close state of these open / close valves, water supply / A configuration is described in which a tank for hot water operation is alternatively selected. And by using a plurality of hot water storage tanks individually, heat conduction between each hot water storage in each hot water storage tank hardly occurs, and hot water and water are respectively added to the upper side and the lower side in one tank. Compared with the case of maintaining the separated state, a more reliable separation state can be obtained between the hot water storage tanks, and the diameter of each hot water storage tank can be reduced by using the same internal capacity as that of a single tank. For example, when it is installed on the veranda of an apartment, it can be installed in close contact with the wall surface.

Patent Document 3 relates to a heat pump type hot water supply facility having a hot water storage tank, and is configured for the purpose of avoiding an insufficient amount of hot water storage or an insufficient rise in hot water temperature without greatly increasing the facility cost. According to this hot water supply equipment, a hot water supply heat pump that heats water by heat absorbed from the outside air, a first temperature sensor that detects the water temperature in the hot water storage tank, a second temperature sensor that detects the outside air temperature, and a water source One or both of a third temperature sensor that detects the temperature of the water, and a 24-hour timer in which a night power period and a first predetermined period before the start of the night power period are set. It is a thing. And in the 1st predetermined time zone before the night electric power time zone start, the outside air temperature detected by the 2nd temperature sensor or the water temperature from the water source detected by the 3rd temperature sensor is below each predetermined value In such a case, the hot water storage mode operation is started earlier than the case where the first control means performs the hot water storage mode operation and the hot water storage mode operation is started simultaneously with the start of the nighttime power period. Therefore, the rise in water temperature and water level in the storage tank will be accelerated.
Japanese Patent Publication No.7-117290 Japanese Examined Patent Publication No. 7-45662 Japanese Patent No. 3371622

  In any of these conventional systems, even if a plurality of hot water storage tanks are used, it has been difficult to use these hot water storage tanks in a large capacity hot water supply system. For example, in Patent Document 1 and Patent Document 2, a plurality of hot water storage tanks are used when using the same amount of hot water storage capacity as in the past, and the size of each hot water storage tank is reduced to enable installation on a veranda or the like. It did not realize continuous hot water supply in a large capacity hot water supply system.

  That is, in Cited Document 1, since a plurality of hot water storage tanks are connected in parallel, each time the hot water storage tanks are replaced, it is necessary to switch the open / close valve mounted on each hot water storage tank. To do so, many operations are required in proportion to the number of hot water storage tanks. Moreover, there is a disadvantage that continuous hot water supply cannot be performed when all hot water storage tanks have run out. Further, in another embodiment of the cited document 1, there is a configuration that enables reheating of hot water storage tanks that are not supplying hot water. However, an extremely large number of pipes and on-off valves are provided between each hot water storage tank and the heat exchanger. Since it is equipped, it is an extremely complex device. As a result, when hot water supply and reheating are performed simultaneously, the operation of each open / close valve becomes extremely complicated, and depending on the operation of each open / close valve, hot water from a plurality of pipes can be concentrated on one hot water supply pipe. There is also a possibility that an excessive load is generated on the piping and the electric water heater, resulting in a great danger.

  According to the cited document 2, hot water boiled by a heat exchanger is temporarily stored in an auxiliary tank, and the hot water in the auxiliary tank is transferred to a plurality of adjacent hot water storage tanks for use. However, when hot water is supplied from the auxiliary tank to the hot water storage tank, the hot water tank is moved from the upper layer to the inside, and hot water is supplied from the upper layer of the hot water storage tank. For this reason, since the hot water transferred from the auxiliary tank to the hot water storage tank is always taken in and out at the upper layer of each hot water storage tank, old hot water remains in the lower layer of the hot water storage tank. In addition, since the heat pump has a characteristic that it cannot be heated by the heat pump unless it is 50 degrees Celsius or less, when the hot water in the hot water storage tank is reheated, it cannot be reheated if the temperature is high, and the hot water that cannot be circulated becomes dead water. There were also inconveniences.

  On the other hand, in Cited Document 3, a temperature sensor and a 24-hour timer are provided in order to avoid a shortage of hot water storage or a rise in hot water temperature. Therefore, in order to construct a large-capacity hot water supply system using this system, an extremely large number of hot water storage tanks are required. In addition, since the amount of hot water that can be used is limited to the amount of hot water that has been boiled in advance, there is also a disadvantage that it becomes impossible to cope with hot water supply that exceeds the amount of hot water storage.

Therefore, the present invention was created to solve the above-described problems, and when performing large-capacity hot water supply,
The load on the electric water heater can be made uniform, and the control operation for hot water supply and reheating is easy, and even when the amount of hot water exceeds the amount of hot water stored in the hot water storage tank, it can flexibly respond to large volumes of continuous hot water supply. The purpose is to provide a large-capacity hot water supply system and an operation method thereof.

  In order to achieve the above object, the first means in the present invention is a hot water supply system configured by combining a plurality of hot water storage type electric water heaters, each hot water storage type electric water heater being a heating means H for heating hot water. And a plurality of hot water storage tanks T and a hot water supply path P through which hot water is circulated, and the hot water supply paths P to a plurality of hot water storage type electric water heaters are alternately connected via electric valves M attached to the respective hot water supply paths P. Connected to each hot water storage tank T so that all the hot water storage tanks T in one hot water storage type electric water heater are connected in series by hot water supply pressure supplied from the opened hot water supply path P. The pipe Q is provided.

  The second means is to use, as the heating means H, a heat pump using carbon dioxide as a refrigerant.

The third means is a series connection pipe Q connected in series so that all the hot water is interlocked with the heating means H for heating the hot water, the hot water supply path P for circulating the hot water, and the hot water pressure supplied by the hot water supply path P. Hot water boiled by each heating means H in an operating method of a large-capacity hot water supply system in which a hot water storage type electric water heater having a plurality of hot water storage tanks T connected thereto is provided and the two hot water storage type electric water heaters are combined and operated alternately Is stored in each hot water storage tank T of each hot water storage type electric water heater, and in each hot water storage tank T in the first hot water storage type electric water heater through a series connection pipe Q and an electric valve M attached to each hot water supply path P. When the amount of hot water in the hot water storage tank T decreases to the limit amount, the electric valve M mounted on each hot water supply passage P is switched to close the hot water supply passage P, and the second hot water storage type electric Each hot water storage tank T is opened by opening the hot water supply path P of the water heater. The water in each hot water storage tank T in the first hot water storage type electric water heater having the hot water supply passage P closed at the same time is replenished by the heating means H, and each hot water storage tank in the second hot water storage type electric water heater. While the amount of hot water in T is reduced to the limit amount, the water is boiled up and continuously operated.

In a fourth means, rotation operation is performed using three or more hot water storage type electric water heaters, and the operation of boiling after hot water supply to the limit amount in the preceding hot water storage type electric water heater is performed by a plurality of subsequent hot water storage type The electric water heater is boiled while the amount of hot water is reduced to the limit amount and is operated so that continuous hot water supply is possible.

A fifth means is a method of operating the large-capacity hot water supply system, wherein when the amount of hot water in each hot water storage tank T in the one hot water storage type electric water heater reaches a set amount before decreasing to a limit amount, The water supply by the hot water supply path P of the electric water heater is divided into the hot water storage tank T and the heating means H, and the hot water reheated by the heating means H is supplied together with the hot water in the hot water storage tank T. Extending the hot water supply time from the hot water storage tank T is a means for solving the problem.

  According to the first aspect of the present invention, the hot water supply paths P to the plurality of hot water storage type electric water heaters are alternately opened and closed via the motor-operated valves M attached to the respective hot water supply paths P, and series connection pipes are connected to the respective hot water storage tanks T. Since Q is provided, the hot water supply pressure supplied from the opened hot water supply path P allows the hot water supply tanks T to be connected in series to supply hot water, so that hot water can be supplied by a simple operation. And the load of each hot water supply path P of an electric water heater can be made uniform.

  According to claim 2, by using a heat pump using carbon dioxide as a refrigerant as the heating means H, it has become possible to construct a powerful hot water supply system using a heat pump having a high coefficient of performance (COP). In addition, due to the characteristics of the heat pump, the inconvenience of old hot water remaining in the lower layer of the hot water storage tank has been solved.

  According to claim 3, when the amount of hot water in the hot water storage tank T decreases to the limit amount, the motor-operated valve M attached to each hot water supply path P is switched to close the first hot water supply path P, and the second hot water storage type electric hot water The hot water supply passage P of the water heater is opened to sequentially supply hot water from the other hot water storage tanks T. At the same time, the water in each hot water storage tank T in the first hot water storage type electric water heater with the hot water supply passage P closed is heated by the heating means H. By boiling up and boiling up until the amount of hot water in each hot water storage tank T in the second hot water storage type electric water heater is reduced to the limit amount, continuous hot water supply with a large capacity is possible. Moreover, the load of the heating means H of an electric water heater can be made uniform.

  According to the fourth aspect, by combining three or more hot water storage type electric water heaters, it is possible to meet a higher demand for hot water supply and to expand the application range of large-capacity hot water supply.

  According to claim 5, when the amount of hot water in each hot water storage tank T in the one hot water storage type electric water heater reaches a set amount before decreasing to a limit amount, water supply by the hot water supply path P of the hot water storage type electric water heater is performed. Is divided into the hot water storage tank T and the heating means H, the hot water reheated by the heating means H is supplied together with the hot water in the hot water storage tank T, and the hot water supply time from the hot water storage tank T is extended. Even if the amount of hot water supply exceeds the amount, it can be flexibly dealt with by reheating at the same time as this hot water supply. As a result, the boiling time in the other hot water storage type electric water heater can be secured.

In addition, the amount of hot water supply and the hot water supply time by the set of hot water storage tanks T can be freely extended by arbitrarily changing the set amount for starting the reheating. Furthermore, since the capacity of each hot water storage type electric water heater can be set to be small, there is also an advantage that a compact installation is possible while being a large capacity hot water supply system.

  As described above, according to the present invention, when performing large-capacity continuous hot water supply, the load of the electric water heater can be made uniform, and the control operation of hot water supply and reheating is facilitated, and the amount of hot water supply can be reduced in the hot water storage tank. Even when the amount of stored hot water is exceeded, various effects such as enabling continuous hot water supply flexibly are provided.

  The best mode of the present invention system is a hot water supply system using two hot water storage type electric water heaters. Each hot water storage type electric water heater includes a heating means H using a heat pump using carbon dioxide as a refrigerant in order to heat hot water. Furthermore, a plurality of hot water storage tanks T and a hot water supply path P for circulating hot water are provided. Then, the hot water supply paths P to the two hot water storage type electric water heaters are alternately opened and closed via the motor-operated valves M attached to the hot water supply paths P, and a plurality of water supply pressures supplied from the opened hot water supply paths P are used. By configuring a system in which the series connection pipes Q are arranged in each hot water storage tank T so that the hot water storage tanks T are connected in series to supply hot water, the original purpose is achieved.

  An embodiment of the present invention will be described below. The main configuration of the system of the present invention is a combination of a plurality of hot water storage type electric water heaters (see FIG. 1). Each hot water storage type electric water heater is provided with a heating means H, a hot water storage tank T, a hot water supply path P, and an electric valve M, respectively. In the illustrated example, two hot water storage type electric water heaters are combined, but it is possible to arbitrarily combine three or more hot water storage type electric water heaters.

  The heating means H is means for heating hot water, and a heat pump, an electric heater or the like is used. In particular, as the heating means H suitable for large-capacity hot water supply, it is possible to construct a powerful hot water supply system having a high coefficient of performance (COP) by using a heat pump using carbon dioxide as a refrigerant.

  The hot water storage tank T is a tank for storing hot water boiled by the heating means H, and a plurality of hot water storage tanks T are arranged in each hot water storage type electric water heater. The illustrated hot water storage tank T uses a set of six hot water storage tanks T. The one set of hot water storage tanks T can store 3000 liters of hot water, and the two sets of hot water storage tanks T have a total capacity of 6000 liters of hot water. But the capacity | capacitance of each hot water storage tank T and the hot water storage amount of the whole hot water storage type electric water heater can be set arbitrarily.

  The hot water supply path P is composed of all the pipes that circulate the water supplied from the water supply valve to the hot water storage tank T and the heating means H and reach the hot water tap. The hot water supply path P is provided with a series connection pipe Q and an electric valve M, which will be described later. Further, in the illustrated hot water supply path P, a water tap 1 that opens and closes water supply from a water source such as a water supply, a water supply port 2 that is installed between the water tap 1 and each hot water storage tank T, and an electric valve from each hot water storage tank T. A hot water supply port 3 installed between M and a mixing valve 4 which adjusts the temperature of the hot water by mixing water with hot water supplied between each motor operated valve M and the hot water tap R via the motor operated valve M , Etc. are installed. Further, a water proportional valve 5 is mounted on the water supply side of the heating means H, and the water proportional valve 5 controls water supply or shut-off to the heating means H. Note that reference numeral 6 in the figure denotes a drainage channel that releases the expanded water in the hot water supply channel P or drains the hot water in the hot water storage tank T during maintenance.

  The series connection pipe Q is configured to connect a plurality of hot water storage tanks T in series to form a set of hot water storage tanks T. The hot water is stored in each hot water storage tank T by the pressure at the time of water supply via the series connection pipe Q. The hot water is discharged in conjunction. In the illustrated example, when water is supplied to the hot water storage tank T from the lower end portion of the hot water storage tank T at the right end, the hot water moves from the upper end portion of the tank to the left through the serial connection pipe Q to the left side. . Such hot water movement continues in all remaining hot water storage tanks T and is finally supplied from the upper end of the hot water storage tank T at the left end to the hot water tap R through the hot water supply path P and the electric valve M.

  The motor-operated valve M opens and closes so as to select and supply one of a plurality of hot water storage type electric water heaters. In the illustrated motor-operated valve M, hot water taps R in the two hot water storage type electric water heaters are respectively arranged in the hot water supply path P of the water. At this time, the hot water supply path P of the water supply in each hot water storage type electric water heater is connected so as to branch from one water supply path and supply water to each hot water storage tank T. As a result, when one of the motor-operated valves M is closed, the closed motor-operated valve M cannot supply water to the hot water storage tank T, so that the open motor-operated valve M is supplied with water to the hot water storage tank T. The hot water is supplied from the hot water tap R through the motorized valve M.

  Next, the operation method of this system will be described. As a main procedure of the operation method, operation is performed in four stages of night water heating operation, initial hot water supply operation, replacement hot water supply operation, and auxiliary reheating operation. Further, the number of hot water storage type electric water heaters to be operated alternately can be arbitrarily set to two or more, but in the illustrated example, a method of operating two hot water storage type electric water heaters will be described.

  In the night water heating operation, the operation is necessary before the initial hot water supply operation or after a long pause, and in each hot water storage tank T of the two hot water storage type electric water heaters (hereinafter, the upper stage is referred to as Unit 1 and the lower stage is referred to as Unit 2). This is an operation in which all water is boiled at night (22:00 to 8:00) (see FIG. 1). At this time, both the two motor-operated valves M are closed and the water proportional valves 5 of the respective heating means H are opened. Then, the heating means H is circulated from each hot water storage tank T and heated to boil all the hot water storage tanks T in the first and second hot water tanks. The next initial hot water supply operation is performed from this state.

  The initial hot water supply operation is an operation of sequentially supplying hot water from the hot water storage tank T of the first unit (see FIG. 2). In this operation, the motorized valve M of the first unit is opened, and the motorized valve M of the second unit is closed. When the amount of hot water in the hot water storage tank T of the first unit is used up to the limit amount, the next replacement hot water supply operation is started.

  In the replacement hot water supply operation, the hot water storage tank T of the first unit is switched to the hot water storage tank T of the second unit to supply hot water (see FIG. 4). In this case, the electric valve M of the first car is closed and the electric valve M of the second car is opened. At the same time, in Unit 1 that has finished the hot water supply, water is stored in the hot water storage tank T, and in order to boil this water by the heating means H, a reheating operation is performed in parallel with the replacement hot water supply operation. In addition, when the amount of hot water in the hot water storage tank T of the second unit has decreased to the limit amount, the replacement hot water supply operation is repeated again to supply hot water from the first unit, and to chase the second unit (see FIG. 6). Such a replacement hot water supply operation is repeated many times as long as there is a demand for hot water supply.

  The auxiliary reheating operation is an operation in which the hot water supply amount and the hot water supply time from one hot water storage type electric water heater are freely increased in the replacement hot water supply operation. For example, before the amount of hot water in the hot water storage tank T of the first unit is reduced to the limit amount, an arbitrary set amount is set in advance, and when the time to reach this set amount is earlier than planned, the heating means H of the first unit In this way, a re-running operation is performed (see FIG. 3). In this auxiliary refueling operation, a part of the water supplied to the hot water storage tank T of the first unit is diverted to the heating means H, and the hot water is supplied together with the hot water in the hot water storage tank T to supply the hot water in the hot water storage tank T. The time required for the amount of hot water to reach the limit is extended, and the time required for boiling up Unit 2 is earned. By arbitrarily changing the set amount, the hot water supply time from the hot water storage tank T can be freely adjusted. Further, by using this chasing operation not only for emergency operation but also for normal operation, large-capacity continuous hot water supply can be achieved even with a compact hot water storage tank T. FIG. 5 shows a state in which the auxiliary reheating operation is performed by the heating means H of the No. 2 machine when the hot water storage amount in the No. 2 hot water storage tank T is reduced to the set amount.

  In addition, when rotating three or more hot water storage type electric water heaters, the hot water operation at night, the initial hot water supply operation, and the auxiliary reheating operation are the same as those described above, but the timing of the replacement hot water operation is as follows. It can be changed arbitrarily depending on the number of hot water storage type electric water heaters. In other words, in the replacement hot water supply operation, the reheating operation in which the preceding hot water storage type electric water heater is heated to the limit amount is heated up while the amount of hot water in the subsequent multiple hot water storage type electric water heaters is reduced to the limit amount. It will be good.

  Note that the present invention is not limited to the illustrated example, and the design change and temperature setting of each component can be arbitrarily changed, and the application can be freely changed without departing from the scope of the present invention. It can be done.

It is the schematic which shows the night-time hot water operation in this invention hot-water supply system. It is the schematic which shows the initial hot water supply driving | operation of No. 1 machine in this invention hot water supply system. It is the schematic which shows the reheating operation of the 1st machine in this invention hot-water supply system. It is the schematic which shows the replacement | exchange hot water supply operation to No. 2 machine in this invention hot water supply system. It is the schematic which shows the reheating operation of the 2nd machine in this invention hot-water supply system. It is the schematic which shows the replacement hot water supply operation to No. 1 machine in this invention hot water supply system.

Explanation of symbols

H Heating means M Motorized valve P Hot water supply path Q Series connection pipe R Hot water tap T Hot water storage tank

1 Water Tap 2 Water Supply Port 3 Hot Water Supply Port 4 Mixing Valve 5 Water Proportional Valve 6 Drainage Channel

Claims (5)

  A hot water supply system configured by combining a plurality of hot water storage type electric water heaters, each hot water storage type electric water heater having a heating means for heating hot water, a plurality of hot water storage tanks, and a hot water supply path for circulating hot water. The hot water supply path to a plurality of hot water storage type electric water heaters is alternately opened and closed via motor-operated valves attached to each hot water supply path, and one hot water storage type is provided by the supply water pressure supplied from the open hot water supply path. A large-capacity hot water supply system, wherein a series connection pipe is provided in each hot water storage tank so that all hot water storage tanks in an electric water heater are connected in series.   The large-capacity hot water supply system according to claim 1, wherein a heat pump using carbon dioxide as a refrigerant is used as the heating means. A heating means for heating the hot water, a hot water supply path for circulating the hot water, and a plurality of hot water storage tanks connected in series with a series connection pipe so that all the hot water is linked by the supply water pressure supplied by the hot water supply path, In a method for operating a large-capacity hot water system in which two hot water storage type electric water heaters are provided and operated in combination with each other, the hot water boiled by each heating means is stored in each hot water storage type electric water heater. Hot water is stored in the tank, and hot water in each hot water storage tank in the first hot water storage type electric water heater is sequentially supplied via an electric valve and a serial connection pipe installed in each hot water supply passage, and the amount of hot water in the hot water storage tank is limited. When the amount is reduced to the amount, the motor-operated valve attached to each hot water supply passage is switched to close the hot water supply passage, and the hot water supply passage of the second hot water storage type electric water heater is opened to sequentially supply hot water from each hot water storage tank, At the same time, the hot water supply path P was closed In the hot water storage type electric water heater, the water in each hot water storage tank is chased by heating means, and while the amount of hot water in each hot water storage tank in the second hot water storage type electric water heater is reduced to the limit amount, it can be continuously heated. A method of operating a large-capacity hot water supply system, characterized in that it is operated in   In the operation method of the large-capacity hot water supply system, rotation operation is performed using three or more hot water storage type electric water heaters. The operation method of the large-capacity hot water supply system according to claim 3, wherein the hot water storage type electric water heater is operated so as to be continuously heated without being heated while the amount of hot water decreases to a limit amount. In the operation method of the large-capacity hot water supply system, when the amount of hot water in each hot water storage tank of the one hot water storage type electric water heater reaches a set amount before decreasing to a limit amount, the hot water supply of the hot water storage type electric water heater is The hot water supply time from the said hot water storage tank is extended by diverting the water supply by a path into the said hot water storage tank and the said heating means, and supplying the hot water reheated with this heating means with the hot water in the said hot water storage tank. Or the operation method of the large capacity hot water supply system of 4.

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