JPH081344B2 - Multi hot water supply system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hot water supply system for a house using a heat pump, and more particularly to a hot water supply system for an apartment house.

2. Description of the Related Art Conventionally, a late-night electric water heater has been known as a device that uses electric power as a heating source for hot water supply in a house.

This is to heat hot water from a heater (85 ° C) from midnight to early morning with cheap electricity to cover the hot water supply load from that morning to midnight. The maximum load of hot water supply in ordinary households is the flooding of the bath, which often occurs from evening to night. Therefore, hot water must be stored from early morning to early evening. In addition, in order not to run out of hot water, it is necessary to install a hot water storage tank according to the maximum load per day within a year.

Further, as a hot water supply system using electric power as a heat source, a hot water supply device using a heat pump device is known.

This is energy saving because it can be operated with high efficiency because heat is drawn from the outside air by the heat pump device, but the boiling temperature is 60 to 70 ° C, which is lower than that of an electric water heater, and therefore the capacity of the hot water storage tank is large. The heating capacity is
It is difficult to make it large due to the equipment price and electric capacity, and it operates for a long time with a low heating amount to store hot water in the hot water storage tank so that it can withstand a large load.

A hot water supply system that uses electric power as a heat source in an apartment
Since the electric water heater is provided in each home, a large hot water storage tank and a relatively large amount of electric power are required, and a large power receiving facility is provided in a residential building of an apartment house. Similarly, a heat pump water heater requires a large hot water storage tank and relatively large electric power.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In a water heater that uses midnight power, as described above, high-temperature hot water must be stored for a long time, and since a hot water storage tank is provided in accordance with the maximum hot water supply load, Since there is an excessively large hot water storage tank for most days, the installation space is large and the amount of heat loss is large. Furthermore, once hot water runs out, there is no reheating function, so there is a problem that hot water cannot be used unless you wait until the next morning.

A water heater using a heat pump device is energy-saving, but as already mentioned, since the heating capacity is small and the boiling temperature is lower than that of the electric water heater, the capacity of the hot water storage tank is further increased. There is a problem that once the hot water is cut off, the waiting time until boiling is long because the reheating capacity is small.
Further, if the heating capacity is increased, the equipment cost becomes high and it becomes impractical.

In an apartment house, both the electric water heater and the heat pump device require a hot water tank installation space for each dwelling unit, and a large amount of electricity capacity is required for each unit, so a large power receiving facility is required for the entire dwelling. There are challenges.

In view of the above-mentioned problems, the present invention has a merit of gathering each dwelling unit in an apartment house, that is, a hot water supply amount per unit fluctuates greatly per day, but is averaged when hot water supply amounts of a plurality of dwelling units are added. In addition, the concept of simultaneous usage rate that the average hot water supply amount required per hour converted to one dwelling unit becomes smaller by shifting the hot water supply usage time zone to each dwelling unit, and converted to one dwelling unit, the capacity is relatively large. A system that installs a small heat pump device with a small-capacity hot water tank and a large heat exchanger for each dwelling unit, and can easily distribute the heat from the heat pump device to each dwelling unit in the required amount. A hot water supply system is provided.

Means for Solving the Problems A heat pump device including a compressor and a condenser, and a hot water tank, a condenser, and a hot water storage unit including a pump are provided in each dwelling unit, and the heat pump device and the condensers of the plurality of hot water storage units are provided. Are connected in parallel by a refrigerant pipe, the lower part of the hot water storage tank of the hot water storage unit and the condenser water inlet are connected by a suction pipe through a pump, and the condenser water outlet and the hot water supply pipe at the upper part of the hot water storage tank are passed through a solenoid valve. It is connected by a pipe and branched from the pipe between the condenser water outlet and the solenoid valve, and a bypass pipe via an electric valve is installed in the suction pipe between the lower part of the hot water storage tank and the pump, and near the condenser water outlet. , A first hot water temperature sensor is provided, a second temperature sensor is provided between the confluence of the bypass pipe and the suction pipe and the condenser water inlet, and a pressure sensor is provided at the outflow pipe of the refrigerant pipe,
The first hot water temperature sensor controls the amount of water flowing in the condenser so that the condenser outlet water temperature is constant, and the second temperature sensor controls the opening of the motor-operated valve provided in the bypass pipe to control the condenser outlet. The bypass amount of high-temperature hot water is controlled according to the heating demand from the hot water storage unit installed in each dwelling unit, and it is mixed with the low-temperature hot water from the hot water storage tank to set the condenser inlet water temperature as the set value, and the refrigerant internal pipe pressure. The number of revolutions of the compressor is controlled so that is constant.

Action As a result, the first temperature sensor of each dwelling unit controls the heating temperature of the hot water, and the second temperature sensor controls the hot water temperature at the inlet of the condenser. As a result, the temperature difference between the hot water and the refrigerant (here, R-12) in the condenser can be controlled, and thus the heat exchange amount can be controlled. Therefore, the control valve is not required on the refrigerant side.

If a dwelling unit supplies hot water and the temperature of the hot water storage tank drops and a heating request is issued to the heat pump device, the compressor will
-12 is operated so as to have a predetermined pressure, and R-12 is supplied to each condenser as a high temperature and high pressure gas. In the condenser to which the heating request is issued, the pump is operated and the hot water is circulated, but the electromagnetic valve is closed and the electric valve is open, so the hot water in the hot water storage tank is not circulated. If the first temperature sensor detects that the hot water in the condenser has been heated to the specified temperature, the electromagnetic valve is opened and the motorized valve is closed at the same time so that the condenser outlet temperature becomes constant. Control to control the circulating amount of hot water. Furthermore, when a heating request is issued from a plurality of units, it is necessary to distribute the output of the heat pump device according to the heating request amount. The required heating amount is
The output of the heat pump device is distributed by predicting the amount of hot water used in the future from the amount of hot water discharged from the hot water storage tank of each dwelling unit and the hot water supply load pattern. As an action for distributing this output, the inlet water temperature of the condenser is returned to the pump intake side through the bypass pipe while controlling the electric valve to part of the hot water supplied from the condenser outlet by the second temperature sensor. , The target condenser inlet water temperature is obtained by mixing with the low temperature hot water from the lower part of the hot water storage tank. Thereby, the condenser inlet water temperature can be controlled, and the refrigerant (R-1 having a constant saturation temperature in the condenser is controlled).
The difference between 2) and the average temperature of hot and cold water inlets and outlets should be large for dwelling units with a large amount of hot water coming out of the hot water storage tank or for those with a large load expected from the hot water supply load pattern, and small for dwelling units with a light load. This allows capacity distribution. The compressor only needs to control the rotation speed so that the discharge pressure is constant.

Embodiment One embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a heat pump device, a compressor 2, an evaporator 3 for pumping heat from a waste heat source, and the like.
The expansion valve 4 is built in and is connected by a pipe line 5. 6, 6 '
Is a hot water storage unit, 7 and 7'are condensers, and 8 and 8'are hot water storage tanks. Lower part 9, 9'of the hot water storage tank of the hot water storage unit 6, 6 '
And condenser water inlets 10 and 10 'are connected by suction pipes 12 and 12' via pumps 11 and 11 ', and condenser water outlets 13 and 13' and hot water tank upper portions 14 and 14 'hot water supply pipes 15 and 15 ′ Is connected via solenoid valves 16 and 16 ′ by pipes 17 and 17 ′, and branched from the pipes 17 and 17 ′ between the condenser water outlets 13 and 13 ′ and the solenoid valves 17 and 16 ′, and the hot water storage tank Bypass pipes 19 and 19 'are provided in the suction pipes 12 and 12' between the lower portions 9 and 9'and the pumps 11 and 11 'through the motorized valves 18 and 18', and near the condenser water outlets 13 and 13 '. , 1st hot water temperature sensor 2
0, 20 'are provided, and the amount of water flowing in the condenser 7, 7'is controlled by the first temperature sensor 20, 20' so that the condenser outlet water temperature becomes constant, by controlling the number of revolutions of the pumps 11, 11 ', Confluence part of bypass pipes 19 and 19 'and suction pipes 12 and 12'
A second temperature sensor 22, 22 'is provided between 21, 21' and the condenser water inlet 10, 10 ', and this second temperature sensor 22, 2'
2 ′ allows the condenser water outlets 13, 1 to open at the opening of the motorized valves 18, 18 ′.
By controlling the bypass amount of the hot water supplied from 3 ', the hot water supply from the hot water storage tanks 8 and 8'and the merging parts 21, 21'
And the condenser inlet water temperature is set lower for dwelling units where a large load is expected and set higher for dwelling units where the load is low. 23 and 23 'are controllers for the pump 1 by the first temperature sensor 20, 20', the second temperature sensor 22, 22 'and the temperature sensor 24, 24' in the hot water tank 8, 8 '.
1, 11 ', solenoid valves 16, 16', motorized valves 18, 18 'are controlled,
A heating request is issued from the hot water storage unit 6, 6'to the heat pump device 1. In response to a heating request from the hot water storage unit 6, 6 ', it enters the controller 25 of the heat pump device 1 to start the compressor 2, and at the same time, the discharge pressure is detected by the sensor 26 and the inverter 27 rotates so that the discharge pressure becomes a predetermined pressure. Are in control. The heat pump device 1 and the hot water storage units 6 and 6'include the condensers 7 in the middle of the going pipe 28 and the returning pipe 29 of the refrigerant pipe.
7'are respectively branched and connected. 30 and 30 'are hot water taps, 3
1, 31 'are water inlets.

Next, the operation of the structure of this embodiment will be described. First of all, the hot water storage unit 6, 6'of each dwelling unit is in a boiling state, that is, the temperature sensor 24, 24 'is set to a predetermined value (here,
Assuming that the temperature is 60 ° C.) and a certain house opens the hot water tap 30 and taps, city water is injected into the hot water tank 8 from the water supply port 31, and the temperature sensor 24 detects a low temperature and controls it. The heating request is output from the device 23 to the controller 25 of the heat pump device 1. As a result, the compressor 2 is started and the rotation speed is controlled by the inverter 27 so that the pressure in the going pipe 28 becomes a predetermined pressure. The hot water is sent to the condenser 7 by the pump 11, and the solenoid valve 16 is closed and the motor-operated valve 18 is opened by the first temperature sensor 20 until the temperature reaches a predetermined value (here, 62 ° C.) or more. The hot water supply of is not circulated in the condenser 7. After that, the hot water is gradually heated, and when the first temperature sensor 20 detects a predetermined temperature or higher, the solenoid valve 16 is opened and the motor-operated valve 18 is closed.
The hot water therein is circulated by the first temperature sensor 20 while controlling the flow rate of the pump 11 so as to be 62 ° C. The heated hot water flows through the pipe 17, the solenoid valve 16, and the hot water supply pipe 15 from the upper part 14 of the hot water storage tank to the upper part in the hot water storage tank 8 and is stored therein. Next, a case where a heating request is made from another dwelling unit while heating one dwelling unit will be described. When there are a plurality of heating requests, it is necessary to distribute the output of the heat pump device 1 to each dwelling unit. Heat pump device 1 is for multiple units
Small hot water storage tanks 8 and 8'with the concept of simultaneous usage rate that equipment capacity per unit can be reduced by installing a stand
Since the condensers 7 and 7'having a relatively large capacity are provided, the total heat exchanging capability of the condensers 7 and 7'that require heating may exceed the capacity of the heat pump device 1. At that time as well, similarly to the above, it becomes necessary to distribute the capacity of the heat pump device 1 to the dwelling units that require heating. This distribution method should be based on a method that has a low probability of hot water shortage. In order to obtain this required heating amount, predict the future hot water supply usage from the amount of hot water discharged and the hot water supply load pattern of each dwelling unit, and decrease it for dwelling units that are likely to use more and less for dwelling units that use less. To decide. It is possible to control the amount of heat exchange by changing the inlet water temperature of the condenser 7 and controlling the average temperature difference between the R-12 condensation temperature and the hot water supply water temperature.

FIG. 2 shows a graph of the condensing capacity with respect to the inlet water temperature.
The condenser outlet water temperature is determined to be 62 ° C. by the first temperature sensor 20, and the R-12 also controls the rotation speed so that the discharge pressure of the compressor 2 is constant, so the condensation temperature is determined and the inlet water temperature is When changed, the temperature difference between the condensation temperature in the condenser 7 and the hot water temperature can be changed, and the heat exchange capacity can be changed. In other words, the bypass pipe is set by the second temperature sensor 22 so that the water temperature at the inlet of each condenser becomes a set value corresponding to the load amount of each dwelling unit.
By controlling the opening of the motorized valve 18 provided in 24,
By changing the bypass amount of the hot water supplied to the condenser outlet heated to 62 ° C and mixing it with the low-temperature hot water drawn by the pump 11 from the lower part 9 of the hot water storage tank at the merging part 21, the required heating amount for each dwelling unit can be obtained. Controlled temperature. The heat pump device 1 includes a condenser 7
On the other hand, in order to guarantee the condensing temperature, it is only necessary to control the number of revolutions of the compressor 2 so as to keep the pressure of the going pipe 28 constant. For each condenser 7 and 7 ', the circulation amount of the refrigerant R-12 is required. Does not need control of.

FIG. 3 shows a control flowchart which is an embodiment of the present invention. Briefly described, if the hot water tank sensor 24 is 60 ° C. or higher, it is all OFF, and if it is 60 ° C. or lower, a heating request is issued, the compressor 2 is turned ON, and the compressor rotation speed control is performed at a constant discharge pressure. At the same time, the water pump 11 is operated and the first hot water temperature sensor
Until 20 exceeds 62 ° C., the solenoid valve 16 is turned off and the motor operated valve 18 is operated so that the hot water supplied to the hot water storage tank 8 is not heated. When the first hot water temperature sensor 20 exceeds 62 ° C, the solenoid valve 16 is turned on and the electric valve 18 is closed to control the rotation speed of the water pump 11 so that the condenser outlet water temperature is kept constant at 62 ° C. On the other hand, if a plurality of heating requests are received, operate the electric valve 18 of each dwelling unit to
The target of the temperature sensor 22 is set to a temperature according to the load, and the capacity distribution can be performed by controlling the temperature of each condenser water inlet.

As described above, when the capacity of the heat pump device 1 is distributed, the condensers 7 and 7'are controlled by the hot water supply side, that is, the hot water temperature of each condenser water inlet is changed according to the load. The heat exchange capacity can be changed, and most of the output of the heat pump device of the dwelling unit, which has a large heating demand, can be distributed, so that the hot water runs out.

Further, each condenser 7, 7'needs no refrigerant R-12 control valve for distribution, and if there is a heating request even in one dwelling unit, the refrigerant is circulated and the condenser 7, 7'of the dwelling unit which does not have a heating request. Since it is preheated, the next heating request can be responded promptly and the heating request can be promptly responded to, and the time delay with respect to the heating request is small, and the occurrence of hot water shortage is reduced accordingly.

EFFECTS OF THE INVENTION The present invention makes the condensation temperature of a multi-hot water supply system constant,
By varying the condenser water inlet temperature according to the load,
The capacity distribution to each condenser can be realized without providing a control valve on the refrigerant side. Furthermore, it is possible to accommodate a large hot water supply load even with a small hot water storage tank by providing one heat pump device for a plurality of houses and incorporating the concept of simultaneous usage rate that the heat pump device capacity per house can be made smaller than individual devices. Therefore, a multi-hot water supply system with great convenience can be provided.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a multi-hot water supply system according to an embodiment of the present invention, and FIG. 2 is a condensation capacity diagram with respect to a condenser inlet water temperature in the system. FIG. 3 is a flowchart of control in the system. 1 ... Heat pump device, 2 ... Compressor, 6, 6 '...
Hot water storage unit, 7, 7 '... Condenser, 8, 8' ... Hot water storage tank, 16, 16 '... Solenoid valve, 18, 18' ... Motorized valve.

Claims (1)

[Claims] 1. A heat pump device including a compressor and an evaporator, and a hot water storage unit including a hot water storage tank, a condenser, and a pump is provided in each dwelling unit, and the heat pump device and the condensers of the plurality of hot water storage units are used as a refrigerant. Connected in parallel by piping, the lower part of the hot water tank of the hot water storage unit and the condenser water inlet are connected by a suction pipe via a pump, and the condenser water outlet and the hot water supply pipe at the upper part of the hot water storage tank are piped via a solenoid valve. And a branch pipe from the pipe between the condenser water outlet and the solenoid valve, and a bypass pipe via a motorized valve is installed in the suction pipe between the lower part of the hot water tank and the pump. The first hot water supply water temperature sensor is provided, the second temperature sensor is provided between the confluence of the bypass pipe and the suction pipe and the condenser water inlet, and the pressure sensor is provided at the outflow pipe of the refrigerant pipe. The water temperature sensor keeps the condenser outlet water temperature constant. The amount of water flowing in the condenser is controlled by the second temperature sensor, and the bypass amount of the high temperature hot water at the condenser outlet is heated by the hot water storage unit provided in each dwelling unit by the opening of the electric valve provided in the bypass pipe. It is controlled according to the required amount, mixed with low temperature hot water from the hot water storage tank to set the condenser inlet water temperature as a set value, and controlling the rotation speed of the compressor so that the refrigerant internal pipe pressure becomes constant. Multi hot water supply system.