JPH0463986B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a residential oil supply system using a heat pump,
Among these, it particularly relates to a refueling device for housing complexes.

BACKGROUND TECHNOLOGY The use of electric power to heat the fuel supply in a house is desirable because it does not generate waste air, unlike heating by combustion, and is therefore clean, free from flames, and safe because there is no risk of gas leakage. However, with electric instant heating equipment, not only is the fuel price expensive, but the power distribution capacity per residential unit is large, and when these devices are aggregated, it places a large burden on the local power supply infrastructure. This is not possible. Therefore, in contrast to conventional electric water heaters, late-night electric water heaters have become popular, as they use cheap late-night electricity to store hot water that has been heated to around 85℃ using an electric heater in the morning, providing hot water supply until midnight on the same day. ing.

The amount of hot water used in actual houses not only varies greatly depending on the season, but also varies widely from day to day even during the same season. During the day, excessive hot water is left in storage, which unnecessarily increases heat dissipation loss.

BACKGROUND ART There is known a water heater using a heat pump that can heat water with an amount of electricity equal to (1/coefficient of performance) the amount of electricity required for heating with an electric heater. In this case, the power consumption is low, so the power distribution capacity per dwelling unit is small, and an instant heating method is also possible, but the equipment is expensive and the heat capacity of the equipment itself is large, so ineffective energy is consumed for heating, so it is not practical. A hot water storage type, in which small equipment is operated continuously, is used. Currently, the boiling temperature using heat pumps is as low as 60°C, so the storage tank must be larger than with electric heaters.

In the conventional technology, water heaters using heat pumps have high energy efficiency, that is, low fuel costs, small power distribution capacity, and are superior to electric heater types, but they are expensive for both equipment and hot water storage tanks, and require a large installation area. This is not an acceptable condition.

As already mentioned, the daily amount of hot water used in each residence fluctuates widely, but in the case of multiple residences, the larger the number, the more it is averaged out, and the time of use also differs between each residence, so it is converted to a per-dwelling amount. The average amount of hot water required per hour becomes smaller. Regarding this, it is generally known in the field of building equipment that the simultaneous usage rate is less than 1. The hot water supply system based on this idea is called the housing central type, in which a heat source with a relatively small capacity is installed per housing unit, and each housing unit is heated to a temperature of 60°C.
Hot water is provided. With this system, each dwelling unit can freely use the amount of hot water it needs;
It is necessary to circulate hot water 24 hours a day, which is not economical because the pump power required for this and the heat loss from the piping surface for circulation are large.

Problems to be Solved by the Invention As mentioned earlier, electric hot water supply is clean and highly safe, and is particularly suitable for hot water supply systems in high-rise apartment complexes. For systems installed in each dwelling unit, the power distribution capacity per dwelling unit is quite large, and there is a limit to the amount of hot water each dwelling unit can use per day, making it difficult to meet the demand for hot water supply in homes, which is expected to increase in the future. There's a problem.

Installing a heat pump and a hot water storage tank in each dwelling unit, which reduces the power distribution capacity and saves energy, has a limit to the amount of hot water that can be used. However, there are economical problems in terms of both equipment costs and installation area.

A residential central hot water system that supplies hot water directly to each residential unit requires a large amount of power to circulate the hot water, has low energy efficiency due to heat loss from the surface of the hot water piping, and has problems in terms of fuel costs.

Means for Solving the Problems The present invention is an extremely excellent new hot water supply system for apartment buildings that combines the advantages of the aforementioned individual system in which a heat pump and hot water storage tank are installed in each dwelling unit, and the central system for residential buildings. be.

For multiple units, one heat pump unit containing an evaporator and compressor is provided as a heat source, and each unit is equipped with a small-capacity hot water tank, and each hot water tank has a condenser and is heated by it. Install a hot water heat exchanger,
Each condenser is connected to the heat pump unit in parallel through a heat pump working medium conduit.

Effects In the hot water supply device of the present invention, the hot water heating by the heat pump reduces the power distribution capacity to (1/coefficient of performance) compared to the electric heater type, has high energy efficiency, and operates with low fuel cost. In the water heater of the present invention, which installs one heat pump unit for multiple units, based on the principle that the simultaneous usage rate in a group of units is much smaller than 1, the equipment capacity converted per unit may be small.
As a result, not only will equipment costs be reduced, but the demand for hot water, which fluctuates widely from day to day, will be reduced.
A temperature sensor installed in the middle of the hot water storage tank determines which units use the most hot water, and by heating them preferentially, an almost unlimited supply of hot water can be achieved.
In addition, when the hot water tap is opened in each residence, since that residence is equipped with a hot water storage tank, the hot water is immediately released as in the individual method, and the heat pump unit that is the heat source is activated at the same time as the hot water tap is opened. The high-pressure working medium vapor is sent through a pipe to the condenser of the hot water storage tank, where it is condensed and liquefied, and the new city water entering the hot water storage tank is heated semi-instantaneously in a hot water heat exchanger to the hot water storage temperature. do.

Embodiments First, the basic concept of the water heater of the present invention will be explained. The principle that the hot water supply system can meet the hot water demand of each dwelling unit without limit even though the capacity of the hot water storage tank and heat pump unit is small in terms of one dwelling unit is based on the concept that the simultaneous usage rate in an apartment complex is 1 or less. It is. This concept of a simultaneous usage rate of 1 or less holds true in apartment complexes with at least several dozen or more units, but with the water heater of the present invention, the combination of 5 to 10 units causes large statistical fluctuations, and in a short period of time. However, there may be times when the concurrent usage rate is close to 1. In order to solve this problem, the amount of hot water distributed to each dwelling unit is controlled.

Next, the specific configuration will be explained with reference to FIG. 1. The pipes 9, 6, 7, 8 are filled with working medium R12, and when the compressor 1 is in operation, the low pressure R12 vapor in the pipe 7 is compressed by the compressor 1 and converted into high pressure vapor. It is then discharged into the pipe line 8. The high-pressure R12 steam in pipe 8 is passed through pipes 14 and 24, and plugs 15 and 2.
8, the water is condensed and liquefied in condensers 16 and 29, and heats hot water heat exchangers 19 and 34. In other words, heat is supplied from the heat pump unit to the hot water storage tank of each dwelling unit by the vapor phase of the heat pump cycle working medium, and the high pressure working medium vapor released from the compressor in the heat pump unit is supplied by its own pressure difference. The water flows into a condenser installed in each hot water storage tank, where it is condensed and liquefied to generate heat of condensation, which heats the hot water heat exchanger.

Although the capacity of the heat pump unit and the hot water storage tank are small when calculated per dwelling unit, the condenser and hot water heat exchanger heated by it enable instant heating, so the condenser and hot water supply of an individual heat pump water heater are small. It has several times the capacity of a heat exchanger.

The liquefied working medium R12 enters line 9 through lines 10, 25, enters the evaporative heat exchanger 2 at low pressure through the expansion valve 3, enters through line 4 and exits in line 5. It receives heat from the heat source water and evaporates into low-pressure steam. The hot water storage temperature in the hot water tanks 18 and 31 is approximately 60℃.
hot water is stored. When the hot water faucets 21 and 35 are opened, city water is supplied from the pipes 13 and 36, and the heat storage tank 1
It accumulates in the lower part of 8,31. When the pumps 11 and 26 are operated, the low-temperature water accumulated in the lower part is sent to the hot water heat exchangers 19 and 34 through the lower part outlets 12 and 27 of the heat storage tanks 18 and 31, where it is instantaneously stored. The upper end 1 of the heat storage tank 18, 31 is heated to the temperature
7, 30 and returns to the heat storage tanks 18, 31. Hot water tank 1
Temperature sensors 22, 23, 32, and 33 are attached to the tanks 8 and 31 at intermediate heights and low positions in the tank, making it possible to measure the surrounding water temperature.

FIG. 2 shows an example of an algorithm for controlling the operation of the device shown in FIG. 1. When the hot water faucet 21 is opened, hot water is released, but the city water corresponding to the amount released is piped into the pipe 1.
Supplied from 3. Since city water has a low temperature and a high density, it accumulates in the lower part of the hot water storage tank 18, and the indicated value of the temperature sensor 23 becomes low. The compressor 1 is operated immediately when the indicated value of the temperature sensor at the lower position of any one of the plurality of hot water storage tanks becomes a predetermined temperature or less. If this corresponds to the hot water storage tank 18, when the compressor 1 starts operating, the pump 11 starts operating, pumps up the low-temperature water accumulated in the lower part of the hot water storage tank 18, and sends it to the hot water heat exchanger 19. The hot water is instantaneously heated to near the temperature of the hot water storage tank, and is sent to the inlet 17 at the top of the hot water storage tank 18. As explained in the previous section, in this water heater, the hot water storage tank in each dwelling unit has a small capacity, but the hot water heat exchanger is large, so the hot water from the hot water faucet 21 is instantly heated together with the originally stored hot water. Since hot water is discharged at the same time, it is possible to fully meet the daily demand for hot water supply. In the above state, when the indicated value of the temperature sensor 33 becomes the next lowest indicated value of the temperature sensor 23, the blocking plug 28 is opened and the pump 26 is operated. As described above, the blockage valves are opened in descending order of temperature according to the temperature indication at the low position of each hot water storage tank, but since each condenser is connected in parallel, the amount of heating distributed to each dwelling unit is As the number of households with open water taps increases, the amount of heating per household decreases, and it may not be possible to keep up with the amount of hot water used by each household. To solve this problem, two steps of the algorithm shown in FIG. 2 are provided.

In order to clarify the following explanation, the heat pump unit, the hot water storage tank for each house, the capacity of the condenser and the hot water heat exchanger heated by it, the number of residential units connected in parallel, that is, the number of hot water storage tanks are explained in detail in the example. In other words, the capacity of the heat pump unit;
15000Kcal/hour, hot water storage tank; 200, condenser and hot water heat exchanger heated by it:
10000Kcal/hour, number of parallel residences: 5.

The control algorithm is clear from the flowchart shown in FIG. When the temperature falls below a predetermined temperature (55°C in this example), compressor 1 of the heat pump unit and pump 1 attached to the corresponding hot water tank 18 are activated.
1, the blockage valve 15 is opened, and the city water coming in from the pipe 13 is instantaneously heated to 60°C and sent to the inlet 17 at the top of the hot water storage tank 18. When the hot water faucet 21 is closed, the supply of city water is cut off, so the low temperature water in the lower part of the hot water storage tank 18 is heated and sent to the upper inlet, lowering the position of the high temperature part in the hot water tank and detecting the low temperature sensor 23. When the indicated value increases and reaches a predetermined value (58° C. in this example), the compressor 1 and pump 11 are stopped, and the occlusion plug 15 is closed. Next, the indicated value of the low position temperature detector 23 is
If the reading on the low-position temperature sensor of the second hot water storage tank falls below 55°C before the temperature reaches 58°C, operate the pump attached to the corresponding hot water tank and open the blockage valve in the same way as above. The number of hot water storage tanks to be heated simultaneously is determined by the amount of hot water that is supplied at one time in an actual house, but in this example, it was most convenient to set the number to three. This control is shown in the steps in FIG.
Next, when the number of hot water storage tanks that require heating exceeds 3, search the indicated value of the temperature sensor located in the middle of all the hot water storage tanks, and find the temperature of the hot water storage tank below a predetermined temperature (55℃ in this example). Priority is given to heating, and the number of hot water storage tanks that are only the number of prioritized hot water storage tanks is the same as the three that were heated first.
The heating state is set in the order of the lowest reading of the low position temperature sensor. This is shown in steps. One of the points of the present invention is that the indicated value of the temperature sensor at the middle position is
By preferentially heating the hot water tank below 55℃,
It is possible to catch up with the amount of hot water used by each dwelling unit and satisfy the demands of all units.

FIGS. 3 and 4 show the results of a numerical experiment regarding the hot water temperature of each residential unit when the multi-heat pump water heater according to the present invention is applied to the actual hot water supply load of five residential units. The results in Figure 3 are
If you apply the control flow steps in the diagram
A drastic drop in hot water temperature was observed between 10pm and 11pm in units No. 4 and 5, posing a practical problem. However, the amount of hot water used per day for both residences reaches 700 to 800 units. On the other hand, the results shown in Fig. 4 are obtained when steps ~ of the control flow shown in Fig. 2 are applied.
It can be seen that hot water supply of approximately 45℃ or higher is guaranteed for all units.

Effects of the Invention The refueling system of the present invention uses a common heat pump for multiple dwelling units, further utilizes the concept that the simultaneous usage rate is 1 or less, reduces its capacity, and furthermore,
This system uses small hot water storage tanks with a capacity of about 1/4 of the maximum amount of hot water supplied to a dwelling unit, and temperature detectors are installed at the middle and lower positions of each tank. When the heating request exceeds the appropriate number of hot water storage tanks (3 in the example), the indicated value of the temperature sensor in the middle position is searched, priority is given to heating the hot water storage tanks below a predetermined temperature, and the hot water tanks that are in the heating state are first heated. The hot water tanks that are the difference between the three hot water storage tanks and the priority hot water storage tank are heated in descending order of the indicated value of the temperature sensor located at the lowest position. By adding a new control system that preferentially heats units (with a small number of units), the hot water demand for all units can be met without limit.
This solution is both economical and convenient.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a water heater according to an embodiment of the present invention, FIG. 2 is a flow diagram of a control algorithm in the same device, and FIGS. 3 and 4 are characteristic diagrams of the same device. 1... Compressor, 2... Evaporative heat exchanger, 16,2
9... Condenser, 19, 34... Hot water heat exchanger, 1
8, 31... hot water tank, 22, 23, 32, 33...
Temperature detector, 15, 28...occlusion valve.

Claims (1)

[Claims] 1 A compressor, an evaporator, a plurality of condensers connected in parallel to each dwelling unit, pipes connected in parallel for flowing a working medium to them, and pipes installed in those pipes and connected to each dwelling unit. A plurality of corresponding plugs, a plurality of hot water storage tanks provided in each dwelling unit that can exchange heat with the condenser, and temperatures provided at middle and low positions of the internal height of each hot water storage tank, respectively. If the indicated value of the low-position temperature sensor falls below a predetermined value, the blockage plug corresponding to the hot water storage tank is opened, and the temperature sensor whose temperature has fallen below the predetermined value is removed. If the number of hot water storage tanks in your possession exceeds a predetermined number, close the plugs corresponding to the hot water storage tanks for which the reading of the temperature sensor in the middle position has fallen below the prescribed value, or A refueling device characterized by opening the taps in sequence.