JP2008082664A - Hot water circulation heating system - Google Patents

Abstract

A hot water circulation heating system that makes use of the characteristics of a heat pump is provided.
A hot water circulation heating system includes a tank 40 for accumulating hot water, a radiator that is disposed in a building and dissipates heat of the hot water to air in the building, a circulation pump for the radiator, and a heat exchanger 41 in the hot water supply tank. And a hot water supply auxiliary dedicated tank external heat exchanger 43 and a heat pump 10. The hot water tank internal heat exchanger 41 disposed in the tank exchanges heat between water from the water supply source and hot water in the tank 40, and supplies the heated water to the hot water supply pipe of the building. A dedicated tank external heat exchanger 43 outside the tank 40 further supplies heat to the heated water. The heat pump 10 supplies heat to the hot water in the tank 40 and supplies heat to the hot water to the hot water supply pipe via the hot water supply auxiliary dedicated tank external heat exchanger 43.
[Selection] Figure 1

Description

  The present invention relates to a hot water circulation heating system, and more particularly to a hot water circulation heating system that performs heating by circulating hot water in a building.

Conventionally, a hot water circulation heating system that heats buildings by generating hot water using a boiler or electric heater and circulating the hot water to the radiators installed in each room in the building has spread mainly in cold regions such as Europe. is doing. For example, in the air conditioning system disclosed in Patent Document 1, cold / hot water supply means for supplying cold / hot water is installed outdoors or underground in a house, and hot water is supplied to heat exchangers and floor heating devices provided in each room. Supplied so that the room can be heated.
JP-A-10-266351

  Thermal efficiency, which is the merit of heat pumps when compared to boilers and electric heaters, when considering adopting a heat pump as a heat source for generating hot water in a hot water circulating heating system that circulates hot water in a building However, no heat pump has actually been used as a heat source for the hot water circulation heating system. The inventor of the present application recognizes that, in a hot water circulation heating system using a conventional boiler or the like as a heat source, simply replacing the boiler with a heat pump will not make full use of the characteristics of the heat pump with excellent thermal efficiency. Yes.

  The subject of this invention is providing the warm water circulation heating system etc. which can fully utilize the characteristic of the heat pump which is excellent in thermal efficiency.

The hot water circulation heating system according to the first invention is a system for heating by circulating hot water in a building, a tank for storing hot water, a radiator, a circulation pump for radiator, a first heat exchanger for hot water supply, A second heat exchanger for hot water supply and a vapor compression heat pump are provided. A radiator is arrange | positioned in a building and dissipates the heat which warm water has to the air in a building. The circulation pump for the radiator flows warm water from the tank to the radiator, and returns the warm water radiated by the radiator to the tank again. The 1st heat exchanger for hot water supply arrange | positioned in a tank makes heat exchange between the water taken in from the water supply source, and the hot water in a tank, heats water, and supplies it to the hot water supply piping of a building. The second heat exchanger for hot water supply arranged outside the tank supplies heat to the water supplied to the hot water supply pipe. The heat pump supplies heat to the hot water in the tank and also supplies water to the water supplied to the hot water supply pipe via the second hot water supply heat exchanger. Note that the hot water stored in the tank and circulated with the radiator by the circulation pump may be liquid and may not be water (H ₂ O).

  Here, the hot water in the tank is heated by the operation of the heat pump. As a result, hot water having a high temperature of, for example, 70 ° C. is stored in the tank. When this high-temperature hot water is sent to the radiator in the building by the operation of the circulation pump, the heat of the hot water moves to the air in the building and the room is heated. And the hot water which temperature fell will return to a tank again. The hot water whose temperature has been lowered is raised again by the operation of the heat pump. On the other hand, the first heat exchanger for hot water supply is provided in the tank, and water taken from the water supply source takes heat from the hot water in the tank when passing through the first heat exchanger for hot water supply, and becomes heated water. It flows into the hot water supply pipe of the building. The heated water flowing through the hot water supply pipe is supplied to a shower, a bathtub, or the like.

  By the way, as a characteristic of a heat pump, generally, the thermal efficiency of a heat pump improves, so that the temperature change range of heating object is wide. For example, for the hot water in the tank, the thermal efficiency of the heat pump when heating 10 ° C. hot water to 70 ° C. is considerably greater than the thermal efficiency of the heat pump when heating 40 ° C. hot water to 70 ° C. (FIG. 8 and FIG. 8). (See FIG. 9).

  In view of this, in this hot water circulation heating system, the heat of hot water stored in a tank is taken away for heating to a radiator in the building and the heat is used for hot water supply. Specifically, the first heat exchanger for hot water supply is installed in the tank, and the water from the water supply source such as tap water is deprived of the heat of the hot water in the tank when passing through the first heat exchanger for hot water supply. is doing. Thereby, since the temperature of the hot water in the tank is lowered, the heat pump that heats the hot water from that temperature to, for example, 70 ° C. can heat the hot water with very high thermal efficiency. Thereby, energy saving can be achieved. Furthermore, assuming that hot water is supplied by burning gas or the like here, a gas water heater is not necessary and the amount of gas used is reduced, and the work related to hot water supply is handled by a heat pump with high thermal efficiency. Therefore, further energy saving can be achieved.

  Here, the water supplied to the hot water supply pipe can be heated by a heat pump via the second hot water supply heat exchanger. For this reason, even when the temperature of the hot water in the tank is low and the water cannot be heated to a temperature suitable for hot water supply only by the first heat exchanger for hot water supply, the hot water supply temperature falls below the required temperature or the hot water cannot be supplied. It is possible to suppress the problem that the time zone occurs. Furthermore, since the heat pump has a function of supplying heat to the hot water in the tank and a function of supplying heat to the water supplied to the hot water supply pipe via the second hot water supply exchanger, Compared with the case where a booster heater or the like is used instead of the second heat exchanger, the running cost or the like can be suppressed.

  The hot water circulation heating system according to the second invention is the hot water circulation heating system according to the first invention, further comprising a control unit. The controller causes the heat pump to supply heat to the water supplied to the hot water supply pipe via the hot water supply second heat exchanger when the ability of heating the water by the hot water supply first heat exchanger is insufficient.

  A hot water circulation heating system according to a third aspect of the invention is the hot water circulation heating system of the second aspect of the invention, further comprising a hot water heating circulation pump and a hot water supply auxiliary circulation pump. The hot water heating circulation pump flows hot water from the tank to the heat pump, and returns the hot water from the heat pump to the tank again. The hot water supply auxiliary circulation pump circulates a fluid carrying heat from the heat pump to the hot water supply second heat exchanger between the heat pump and the hot water supply second heat exchanger. And a control part operates the circulating water pump for hot water supply assistance, when the capability of the water heating by the 1st heat exchanger for hot water supply is insufficient.

  In the second and third aspects of the invention, only when necessary, the second heat exchanger for hot water supply is used to control the supply of heat from the heat pump to the underheated water. Can be avoided.

  A hot water circulation heating system according to a fourth invention is the hot water circulation heating system according to any one of the first to third inventions, wherein the heat pump uses carbon dioxide as a refrigerant.

  Up to now, fluorocarbons have been widely used as a medium (refrigerant) for transporting heat energy in the refrigeration cycle in the heat pump, but in the future, there is a tendency to adopt carbon dioxide as a refrigerant. However, in general, when carbon dioxide is used as a refrigerant, as compared with the case where fluorocarbon is used as a refrigerant, when the temperature of the heating target before heating becomes relatively high, the drop in thermal efficiency becomes severe. Here, there is a difference depending on the outside air conditions and the temperature of hot water after heating. For example, when the temperature of hot water before heating is about 50 ° C., carbon dioxide is compared with a refrigerant called R410A which is one of hydrochlorofluorocarbons. When using as a refrigerant, the thermal efficiency (COP) may drop to nearly half. Therefore, the first to fourth inventions are particularly useful in a hot water circulation heating system that employs a heat pump using carbon dioxide as a refrigerant.

  A hot water circulation heating system according to a fifth invention is the hot water circulation heating system according to any one of the first to third inventions, wherein the heat pump uses a fluorocarbon refrigerant as the refrigerant. The CFC refrigerant is, for example, a refrigerant called R410A, a refrigerant called R407C, a refrigerant called R32, or the like, which is an HFC refrigerant.

  A hot water circulation heating system according to a sixth invention is the hot water circulation heating system according to any one of the first to third inventions, wherein the heat pump uses a refrigerant having a GWP of 200 or less as a refrigerant. GWP is a global warming potential (Global Warming Potential), and indicates the effect of warming that greenhouse gases have over 100 years on the basis of carbon dioxide.

  A hot water circulation heating system according to a seventh aspect is the hot water circulation heating system according to any one of the first to third aspects, wherein the heat pump uses an HC refrigerant that is a natural refrigerant as a refrigerant. The HC refrigerant that is a natural refrigerant is, for example, propane or butane.

  According to the first invention, the temperature of the hot water in the tank is lowered, the heat efficiency of the heat pump is increased, energy can be saved, and the temperature of the hot water in the tank is low so that the first heat exchanger for hot water supply is sufficient. Even when the water cannot be heated to a temperature suitable for hot water supply, it is possible to suppress problems such as the hot water supply temperature being lower than the required temperature or a blank time zone during which hot water cannot be supplied. Moreover, cost can be suppressed compared with the case where a booster heater etc. are used instead of the 2nd heat exchanger for hot water supply.

  According to the second and third inventions, useless heat supply can be avoided.

<Main configuration of hot water circulation heating system>
The structure of the hot water circulation heating system which concerns on one Embodiment of this invention is shown in FIGS. The hot water circulation heating system is a system that circulates hot water in a building and performs heating and has a hot water supply function, and includes a tank 40 for storing hot water, radiators 61a and 62a in the room, and radiators 69b, 69c, and 69e in the toilet. A circulation pump 51 for indoor heating, a vapor compression heat pump 10 for heating hot water, a circulation pump 25 for heating hot water, a heat exchanger 41 for hot water supply tank, and an external heat exchanger for tank for auxiliary hot water supply 43, a heated water spraying device 75, and a control unit 20.

  The indoor radiators 61 a and 62 a are arranged in the living rooms 61 and 62 of the building and dissipate the heat of the hot water to the indoor air of the living rooms 61 and 62.

  The radiators 69b, 69c, and 69e in the toilet are disposed in the toilet 69 of the building, and radiate the heat of the hot water in the toilet 69.

  The indoor heating circulation pump 51 allows hot water to flow from the tank 40 to the indoor radiators 61a and 62a and the radiators 69b, 69c and 69e in the toilet, and the indoor radiators 61a and 62a and the radiators 69b, 69c and 69e in the toilet. The heated hot water is returned to the tank 40 again. The hot water that has left the tank 40 flows through the in-room radiators 61 a and 62 a, then flows through the in-toilet radiators 69 b, 69 c, and 69 e and returns to the tank 40.

  The heat pump 10 includes a compressor 11, a radiator 12, an expansion valve 13, and an evaporator 14, takes heat from the outside air by the evaporator 14, and heats hot water flowing from the tank 40 by heat released from the radiator 12. To do.

  The hot water heating circulation pump 25 allows hot water to flow from the tank 40 to the radiator 12 of the heat pump 10, and returns the hot water from the radiator 12 of the heat pump 10 to the tank 40 again.

  The hot water tank internal heat exchanger 41 is disposed in the tank 40, exchanges heat between the water taken from the water supply source and the hot water in the tank 40, and heats the water to supply it to the hot water supply pipe 72 of the building. To do. The water heated by the hot water tank internal heat exchanger 41 and supplied to the hot water supply pipe 72 is hereinafter referred to as heated water. In addition, the water taken in from the water supply source and supplied to the hot water supply pipe 72 and the hot water in the tank 40 do not mix with each other.

  The dedicated hot water supply auxiliary tank external heat exchanger 43 is built in the hot water supply auxiliary unit 45 disposed outside the tank 40, and is heated by the hot water supply tank internal heat exchanger 41 and supplied to the hot water supply pipe 72. Further heating as necessary. This dedicated hot water supply auxiliary tank external heat exchanger 43 heats the heated water from the hot water supply tank internal heat exchanger 41 and the heat medium (water or the like) circulated through the circulation path 33 by the hot water supply auxiliary circulation pump 46. Heat exchange with the fluid for movement), and heat can be further applied to the heated water. The heat medium flowing through the circulation path 33 takes heat from the radiator 12 of the heat pump 10, and carries the heat to the hot water supply auxiliary tank external heat exchanger 43 by the hot water supply auxiliary circulation pump 46. The hot water supply auxiliary circulation pump 46 operates based on a command from the general controller 29 described later, and circulates the heat medium between the radiator 12 of the heat pump 10 and the hot water supply auxiliary dedicated tank external heat exchanger 43.

  The heated water spraying device 75 is a device that sprays heated water supplied from the hot water tank internal heat exchanger 41 to the hot water supply pipe 72 onto the outer surface of the evaporator 14 of the heat pump 10.

The hot water stored in the tank 40 and circulated through the closed loop by the indoor heating circulation pump 51 and the hot water heating circulation pump 25 is normal water here, but it may be liquid and is not necessarily water. (H ₂ O) may not be used. If there is a liquid that can reduce the power of the indoor heating circulation pump 51 and the hot water heating circulation pump 25 and can reduce the size of the piping 52, 31 and the like serving as a circulation route smaller than water (H ₂ O), It is desirable to use a liquid. Similarly, the heat medium circulated through the circulation path 33 may not necessarily be water (H ₂ O).

<Overview of hot water circulation heating system>
In the hot water circulation heating system, the hot water flowing from the tank 40 to the radiator 12 of the heat pump 10 by the operation of the hot water heating circulation pump 25 is heated using the heat released from the radiator 12 by the operation of the heat pump 10. As a result, high-temperature hot water of about 70 ° C. is returned from the heat pump 10 to the tank 40. On the other hand, the hot water in the tank 40 is sent to the indoor radiators 61 a and 62 a in the living rooms 61 and 62 and the radiators 69 b, 69 c and 69 e in the toilet 69 by the operation of the circulation pump 51 for indoor heating. The heat of the hot water moves around the indoor air of the living rooms 61 and 62 and the radiators 69b, 69c, and 69e in the toilet, and the living rooms 61 and 62 are heated. In the toilet 69, the washing water in the toilet tank 69a and the toilet seat 69d Etc. are warmed. Then, the hot water whose temperature has dropped to about 10 ° C. to 20 ° C. is returned to the tank 40 again. The hot water whose temperature has been lowered is raised again by the operation of the heat pump 10.

  Thus, here, the tank 40 connected by the piping 31 and the heat pump 10 are circulated, the tank 40 connected by the piping 52, the radiators 61a and 62a in the room, the radiator 69b in the toilet, A second loop that circulates through 69c and 69e is formed, and hot water circulates through each loop. As a result, the heat collected from the outside by the operation of the heat pump 10 or the heat generated by the operation of the compressor 11 is finally passed through the hot water stored in the tank 40 and finally the room air and the toilet 69 in the living rooms 61 and 62. Will move to each part.

  In addition, a hot water tank internal heat exchanger 41 is provided in the tank 40, and water taken from the water supply source heats from the hot water in the tank 40 when passing through the hot water supply tank internal heat exchanger 41. It is deprived of heated water and flows into the hot water supply pipe 72 of the building. The heated water flowing through the hot water supply pipe 72 is used in the shower 73, the bathtub 74, and the like. Further, part of the heated water that has flowed into the hot water supply pipe 72 is sprayed on the outer surface of the evaporator 14 of the heat pump 10 by the heated water spraying device 75. This spraying is periodically performed under a predetermined condition in which the evaporator 14 of the heat pump 10 is frosted.

<Detailed configuration of tank 40>
The tank 40 is installed indoors. The tank 40 is provided with a plurality of temperature sensors (thermistors) 40a to 40e for the purpose of measuring the temperature of the hot water at a plurality of different height positions. The hot water in the tank 40 naturally has a high temperature at the top and a low temperature at the bottom. The high temperature hot water heated by the heat pump 10 is returned to the vicinity of the center of the tank 40 in the height direction, as shown in FIG. Low-temperature hot water is directed to the heat pump 10 from the lower part of the tank 40. On the other hand, the hot water from the upper part or the central part of the tank 40 is directed to the indoor radiators 61a, 62a in the living rooms 61, 62, and the low-temperature hot water returned from the radiators 69b, 69c, 69e in the toilet is The tank 40 is returned to the lower part or the center part.

  The tank 40 is provided with a booster heater 42 that is used when the heating capacity of the heat pump 10 is insufficient, in addition to the above-described hot water tank internal heat exchanger 41. The booster heater 42 is an electric heater, and when the general controller 29 described later needs to increase the temperature of the hot water in the tank 40 and determines that the desired temperature increase of the hot water cannot be expected only by the heating capacity of the heat pump 10. The hot water in the tank 40 is heated together with the heat pump 10.

<Detailed configuration of heat pump 10>
The heat pump 10 is installed outdoors, and is connected to the compressor 11, the radiator 12, the expansion valve (electric expansion valve) 13, the evaporator 14, and the evaporator 14 that are connected by the refrigerant pipe 15 to constitute the refrigeration cycle. A fan 17 for application and a heat pump control unit 19 are provided. As the refrigerant flowing through the refrigeration cycle, the heat pump 10 employs carbon dioxide (hereinafter referred to as CO2 refrigerant). For this reason, in the heat pump 10, the CO 2 refrigerant enters a supercritical state in the radiator 12. In the refrigeration cycle, the CO2 refrigerant is compressed to a pressure exceeding the critical pressure by the compressor 11 (see the transition from the point A to the point B in FIG. 9) and cooled by the radiator 12, and the temperature gradually decreases and becomes supercritical. Transition from the state to the liquid state (see transition from point B to point C in FIG. 9), decompressed by expansion valve 13 (see transition from point C to point D in FIG. 9), and evaporation by evaporator 14 As a result, the gas is again sucked into the compressor 11 (refer to the transition from point D to point A in FIG. 9).

  The radiator 12 is connected to the first heat transfer pipe connected to the pipe 31 extending from the tank 40, the second heat transfer pipe connected to the circulation path 33 extending from the hot water auxiliary auxiliary tank external heat exchanger 43, and the refrigerant pipe 15. And the third heat transfer tube through which the CO2 refrigerant flows, and the first and second heat transfer tubes are spirally wound around the outer peripheral surface of the third heat transfer tube, or the third heat transfer tube is the first and second heat transfer tubes. It is wound spirally around the outer peripheral surface of the heat transfer tube. Thereby, in the radiator 12, heat exchange is performed between the compressed CO2 refrigerant in a high pressure and high temperature state, and the low-temperature hot water flowing from the tank 40 and the heat medium flowing through the circulation path 33. The heat is transferred from the CO2 refrigerant to the hot water or the heat medium, and the hot water or the heat medium is heated.

<Detailed configuration of indoor radiator such as radiator for heating>
As shown in FIG. 2, the interior radiators 61 a and 62 a are arranged in the interior rooms 61 and 62 of the building, and play a role of radiating the heat of the hot water flowing from the tank 40 to the indoor air of the interior rooms 61 and 62. Here, the two indoor radiators 61a and 62a are illustrated, but this is not intended to limit the quantity. Moreover, the form of the indoor radiators 61a and 62a may be arranged near the window or may be embedded under the floor. Further, the indoor radiators 61a and 62a are arranged in series here, but may be arranged in parallel.

  The toilet radiators 69b, 69c, and 69e include a toilet tank heat dissipation portion 69b, a toilet seat heat dissipation portion 69e, and a toilet radiator 69c. The toilet tank heat radiating portion 69b is provided inside a toilet tank 69a that collects wash water in the toilet 69, and dissipates heat of the hot water to the wash water in the toilet tank 69a. The toilet seat heat dissipating part 69e is provided inside the toilet seat 69d of the toilet 69, and dissipates heat of the hot water to the toilet seat 69d. The in-toilet radiator 69 c radiates the heat of the hot water to the air in the toilet 69.

  In addition, a pipe 52 that connects the tank 40, the radiators 61a and 62a in the room, and the radiators 69b, 69c, and 69e in the toilet to form a loop includes a heating / warming temperature sensor 52a, a heating / warming water return temperature sensor 52b, and a warm water flow rate adjustment Valves 53, 54 and 55 are provided.

<Detailed configuration for hot water supply function>
(Configuration related to normal hot water supply)
The hot water tank internal heat exchanger 41 provided in the tank 40 is a water heat exchanger that uses a copper tube or a stainless steel tube as a heat transfer tube, and as shown in FIG. A hot water supply pipe 71 extending from the hot water supply pipe 71 and a hot water supply pipe 72 for supplying hot water to the shower 73 and the bathtub 74 are connected. The water supply pipe 71 puts room temperature water into the lower end of the hot water tank internal heat exchanger 41. The normal temperature water that has entered the heat exchanger 41 in the hot water tank through the water supply pipe 71 takes heat from the hot water in the tank 40 while moving upward, and is discharged into the hot water supply pipe 72 as heated hot water. Is done. The water supply pipe 71 is provided with a water supply pipe temperature sensor 71a, and the hot water supply pipe 72 is provided with a hot water supply pipe temperature sensor 72a. For example, the water supply pipe temperature sensor 71a detects the temperature of tap water of 5 ° C., and the hot water supply pipe temperature sensor 72a detects the temperature of heated water of 45 ° C. The hot water supply pipe 72 is provided with a hot water supply valve (open / close operation valve) 72b which is an electromagnetic valve.

  As described above, the hot water supply auxiliary dedicated tank external heat exchanger 43 in the hot water supply auxiliary unit 45 provided outside the tank 40 has a heat medium flowing through the circulation path 33 that has taken heat away from the radiator 12 of the heat pump 10. Heat exchange is performed with the heated water exiting the hot water tank internal heat exchanger 41, and flows from the heat medium in the circulation path 33 to the hot water supply pipe 72 from the hot water tank internal heat exchanger 41. Heat is transferred to heated water. As a result, the heated water exiting the hot water tank internal heat exchanger 41 is further heated.

  In addition, although illustration is abbreviate | omitted, the heating water supplied to the shower 73 or the bathtub 74 is mixed with a tap water with a mixing valve, is temperature-controlled, and is sent to the shower 73 or the bathtub 74.

(Use of hot water supply for defrost)
The above-described heated water spraying device 75 guides the heated water heated by the hot water tank internal heat exchanger 41 and supplied to the hot water supply pipe 72 toward the evaporator 14 of the outdoor heat pump 10, and the surface of the evaporator 14. To spray. The heated water spraying device 75 includes a spraying pipe 76 that branches off from the hot water supply pipe 72 and extends to the outside, a defrost valve (open / close operation valve) 77 provided in the middle of the spraying pipe 76, and a tip of the spraying pipe 76. The defrosting nozzle 78 is provided in the part and sprays heated water toward the evaporator 14. As will be described later, the heating water spraying device 75 sprays a part of the heating water toward the evaporator 14 at a predetermined cycle when it is necessary to defrost the evaporator 14. The defrost valve 77 is an electromagnetic valve similar to the hot water supply valve 72b described above, and is opened when water spraying to the evaporator 14 is required based on a command from the general controller 29.

<Detailed configuration of control unit 20>
As shown in FIGS. 1 and 4, the integrated controller 29 controls equipment associated with the heat pump 10 and equipment associated with the tank 40 based on signals input from the outside. The general controller 29 is housed in a casing together with the three-way valves 21 and 22, the hot water heating circulation pump 25, and the hot water supply auxiliary circulation pump 46 to form one control unit 20 (see FIG. 1).

  The three-way valves 21 and 22 draw out hot water from which part of the tank 40 in the height direction and send it out to the radiators 61a and 62a, etc., and cool low-temperature water returned from the radiators 69b, 69c and 69e in the toilet. It is provided to adjust which part of the tank 40 is returned to the height direction. These three-way valves 21 and 22 operate according to instructions from the general controller 29.

  In addition to the three-way valves 21 and 22, the general controller 29 includes a booster heater 42, a heat pump control unit 19, an indoor heating circulation pump 51, a hot water heating circulation pump 25, a hot water supply auxiliary circulation pump 46, and hot water flow rate adjustment valves 53 to 55. The defrost valve 77 is controlled. The general controller 29 receives a measurement result signal from the heating / warming water temperature sensor 52a, the heating / warming water return temperature sensor 52b, the temperature sensors 40a to 40e of the tank 40, the water supply pipe temperature sensor 71a, the hot water supply pipe temperature sensor 72a, and the like. The remote controller / thermostat 91 provided in the living rooms 61 and 62 receives information on the room temperature and the room set temperature.

<Hot water control>
In this hot water circulation heating system, a hot water supply tank internal heat exchanger 41 and a hot water supply auxiliary dedicated tank external heat exchanger 43 are provided as heat exchangers that also have a hot water supply function and heat water taken from a water supply source for hot water supply. The two are deployed. The latter hot-water supply auxiliary dedicated tank external heat exchanger 43 is not always used, and is used only when the hot-water supply temperature detected by the hot-water supply pipe temperature sensor 72a provided in the hot-water supply pipe 72 is less than the required temperature. .

  FIG. 5 shows a schematic control flow of hot water supply control. The heated water heated by the hot water tank internal heat exchanger 41 in the tank 40 flows into the hot water supply pipe 72, and the water temperature is detected by the hot water supply pipe temperature sensor 72a (step S1). In step S2, it is determined whether or not the temperature detected by the hot water supply pipe temperature sensor 72a (the hot water temperature) is equal to or higher than the required temperature. If it is above the required temperature, the heated water heated by the hot water tank internal heat exchanger 41 is discharged as it is. On the other hand, if the detected temperature of the hot water supply pipe temperature sensor 72a is lower than the required temperature, the process proceeds to step S4, and the hot water supply auxiliary circulation pump 46 starts to operate according to a command from the general controller 29. As a result, the heat medium flowing through the circulation path 33 carries heat from the radiator 12 of the heat pump 10 to the hot water supply auxiliary dedicated tank external heat exchanger 43, and is heated by the heat exchanger 41 in the hot water supply tank by the heat. The heated water is further heated, and a hot water temperature higher than the required temperature is secured (steps S5 and S6).

<About energy-saving control using body heat storage>
This hot water circulation heating system is installed in a building such as a house whose outer wall is made of a material having high heat storage properties such as bricks and stones, and an energy saving control using frame heat storage (hereinafter referred to as frame heat storage). (Used energy saving control). When using this body heat storage energy saving control, an extremely high level of energy saving operation can be performed.

  FIG. 6 and FIG. 7 show a simplified control flow of the energy storage control using the housing heat storage. Here, based on this control flow, the energy saving control using the frame heat storage will be described.

  In step S11, first, it is determined whether the heating / warming water return temperature Tin, which is a measurement value of the heating / warming water return temperature sensor 52b, is higher than the first set temperature T1. The first set temperature T1 can be determined based on the temperature of tap water or the like, but is set to 20 ° C., for example. If “No” is determined in step S11, the process does not proceed to step S12 and thereafter. This is because it is determined that the hot water whose temperature has been sufficiently lowered has returned to the tank 40 and the heat efficiency of the heat pump 10 can be kept high. If “Yes” is determined in step S11, the process proceeds to step S12.

  In step S12, it is determined whether the room temperature Trm received from the remote controller / thermostat 91 is higher than the second set temperature T2. The second set temperature T2 is set to a temperature slightly higher than the room set temperature by the user receiving from the remote controller / thermostat 91, for example. If “No” is determined in step S12, the process returns to step S11 without proceeding to step S13 and subsequent steps. This is because if the capacity of the heat pump 10 is reduced when the room temperature is lower than the user's set temperature, the room temperature is further lowered. If “Yes” is determined in step S12, the process proceeds to step S13.

  In step S13, it is determined whether the compressor 11 of the heat pump 10 is an inverter compressor or a constant speed compressor. In the case of an inverter compressor, the process proceeds to step S14, and the frequency of the inverter is set to the lowest settable frequency. On the other hand, in the case of a constant speed compressor, the process proceeds to step S15 and the operation of the compressor 11 is stopped. Further, following Steps S14 and S15, in Step S16, the opening degree of the hot water flow rate adjusting valve 53 is reduced to circulate between the tank 40 and the indoor radiators 61a and 62a and the radiators 69b, 69c and 69e in the toilet. Reduce the amount of hot water for heating to zero or close to zero. By reducing the circulation amount in this way, the amount of energy consumed by the compressor 11 is reduced. However, since the amount of hot water sent from the tank 40 to the indoor radiators 61a and 62a is also reduced, the temperature of the hot water in the tank 40 does not decrease so much. Moreover, if it is a building with high heat storage property, once the inside of the building including the frame is warmed, even if the capacity of the heat pump 10 is reduced, the warmth can be maintained for a while.

  After step S16, the process proceeds to step S17. In step S17, it is determined whether the room temperature Trm is lower than the third set temperature T3. The third set temperature T3 is lower than the second set temperature T2, and is normally set to a temperature slightly lower than the indoor set temperature by the user who is receiving from the remote controller / thermostat 91. If “No” is determined in step S16, the process does not proceed to the next step S18. This is because the warmth in the building can be maintained by the heat accumulated in the housing without increasing the capacity of the heat pump 10.

  If “Yes” is determined in step S17, a timer is started in step S18, and the process proceeds to step S19. In step S19, it is determined whether the room temperature Trm is higher than the third set temperature. If “Yes” is determined in step S19, the process returns to step S17. If it is determined as “No” in step S19, the process proceeds to step S20, and it is determined whether a fixed time has elapsed after the timer is started. If “No” is determined in step S20, the process returns to step S19. After step S17, if the room temperature Trm is again higher than the third set temperature T3, there is no need to increase the capacity of the heat pump 10, and the room temperature Trm continues for a predetermined time and is lower than the third set temperature T3. Since it is desired to increase the capacity of the heat pump 10 only in such a case, the processes in steps S18 to S20 are performed.

  If the room temperature Trm is lower than the third set temperature T3 for a certain period of time, “Yes” is determined in step S20, and the process proceeds to step S21. In step S21, the process performed in step S14 or step S15 and step S16 is canceled. That is, in step S21, when the compressor 11 is a constant speed compressor, the operation of the compressor 11 is resumed, and when the compressor 11 is an inverter compressor, the frequency of the compressor 11 is subjected to normal control. The processing of step S14 that has been set to the lowest settable frequency is canceled. In step S21, the opening degree of the hot water flow rate adjustment valve 53 is increased. As a result, the room temperature Trm, which has been lower than the third set temperature T3, gradually increases.

<About defrosting operation of heat pump 10>
As described above, the heated water spraying device 75 removes the heat of the hot water in the tank 40 by the hot water tank internal heat exchanger 41 and supplies the heated water supplied to the hot water supply pipe 72 to the evaporator 14 of the outdoor heat pump 10. Then, it is spread on the surface of the evaporator 14. This spraying is performed at a predetermined cycle by opening and closing the defrost valve 77 according to an instruction from the general controller 29 that transmits and receives signals to and from the heat pump control unit 19 when defrosting of the evaporator 14 is necessary. Thereby, the frost attached to the evaporator 14 is melted, and the thermal efficiency of the heat pump 10 is improved.

  In addition, about the idea when defrosting is required, it is the same as the idea in the refrigerating cycle which uses the conventional fluorocarbon as a refrigerant | coolant.

<Characteristics of hot water circulation heating system>
(1)
In this system, the hot water in the tank 40 is led to the heat pump 10 by the hot water heating circulation pump 25, and the hot water heated by the heat pump 10 is returned to the tank 40 again. The heat pump 10 is outdoors and the tank 40 is indoors. It is installed. For this reason, the tank 40 is not exposed to the cold outdoor air, the temperature drop of the hot water in the tank 40 is suppressed, and the heat pump 10 can pump up heat from the outdoor air (outside air). Therefore, in this system, a large amount of high-temperature hot water can be efficiently secured in the tank 40.

(2)
In this system, each device (three-way valves 21 and 22, booster heater 42, heat pump control unit 19, compressor 11, expansion valve 13, indoor heating circulation pump 51, hot water heating circulation pump) associated with the heat pump 10 and the tank 40. 25, the hot water supply auxiliary circulation pump 46, the hot water flow rate adjustment valves 53 to 55, the defrost valve 77, etc.) from the remote control / thermostat 91 provided in the living rooms 61, 62, etc. The integrated controller 29 controls the information from the temperature sensors 40a to 40e of the tank 40. Thereby, the heat pump 10 can be optimally operated.

(3)
When the room temperature of the living rooms 61, 62 and the like rises, the building temperature of the building also rises, and the room temperature of the living rooms 61, 62 can be maintained even if the capacity of the hot water circulation heating system is reduced.

  In view of this, when the compressor 11 is a constant speed compressor, in this system, as shown in the control flow of FIGS. 6 and 7, the temperature of the hot water returning from the indoor radiators 61 a and 62 a to the tank 40. When Tin is higher than the first set temperature T1 and the room temperature Trm of the living rooms 61 and 62 is higher than the second set temperature T2, the compressor 11 is stopped and the operation of the heat pump 10 is stopped. . Thereby, energy saving can be achieved. Further, if the operation of the heat pump 10 is stopped, the room temperature Trm of the living rooms 61 and 62 gradually decreases even if there is heat storage in the housing. Therefore, the room temperature Trm keeps the third set temperature T3 for a certain time. When continuously falling, the operation of the compressor 11 of the heat pump 10 is resumed. Thereby, it is possible to prevent the room temperature Trm of the living rooms 61 and 62 from being excessively lowered while saving energy.

  Similarly, when the compressor 11 is an inverter compressor, in this system, as shown in the control flow of FIGS. 6 and 7, the temperature Tin of the hot water returning from the indoor radiators 61a and 62a to the tank 40 is When the room temperature Trm of the living rooms 61 and 62 is higher than the first set temperature T1 and higher than the second set temperature T2, the frequency of the inverter of the compressor 11 is set to the lowest settable frequency and the heat pump I try to drop 10 abilities. Thereby, energy saving can be achieved. Further, if the capacity of the heat pump 10 is kept low, the room temperature Trm of the living rooms 61 and 62 gradually decreases even if heat is stored in the housing. Therefore, the room temperature Trm keeps the third set temperature T3 constant. When the time continuously falls below, the frequency of the inverter of the compressor 11 is returned to the state according to the normal control. Thereby, it is possible to prevent the room temperature Trm of the living rooms 61 and 62 from being excessively lowered while saving energy.

  The feature of the present system described above is particularly effective in a building such as a house having a large amount of heat storage in a housing that is difficult to cool once heated.

(4)
As a characteristic of the heat pump, generally, the heat efficiency of the heat pump is improved as the temperature change range of the heating target is wider. When this is applied to the present system, for example, with respect to the hot water in the tank 40, the heat efficiency of the heat pump 10 when heating the hot water of 10 ° C. to 70 ° C. is higher than the thermal efficiency of the heat pump 10 when heating the hot water of 40 ° C. to 70 ° C. The thermal efficiency is considerably larger (see FIGS. 8 and 9).

  As shown in FIG. 8, when 40 ° C. warm water is heated to 70 ° C., H3 corresponding to the amount taken from the outside air by the evaporator 14 is relatively smaller than H1 corresponding to the work amount of the compressor 11. Compared to the small value, as shown in FIG. 9, when 10 ° C. hot water is heated to 70 ° C., the evaporator 14 generates H 1 corresponding to the work amount of the compressor 11 from the outside air. H2 corresponding to the amount taken in is a relatively large value. In the former case, considering the power generation efficiency when generating electric energy to be supplied to the compressor 11, only heat less than 1.0 times the consumed energy is generated. In the latter case, 1. It generates 2 to 1.4 times as much heat.

  Thus, in the heat pump of the present system that employs a CO 2 refrigerant, reducing the temperature of the hot water flowing from the tank 40 to the radiator 12 greatly contributes to the improvement of thermal efficiency. It will be.

  In view of this, in the present system, a radiator (non-toilet radiator 69b, 69c, 69e) is also provided in the toilet 69 that is not a living room, and after the hot water that has exited the tank 40 flows through the indoor radiators 61a, 62a, At least one of the radiators 69b, 69c, 69e in the toilet is configured to flow. Thereby, for example, the warm water that enters the indoor radiators 61a and 62a at 70 ° C. and exits the indoor radiators 61a and 62a at 40 ° C. decreases the temperature by passing through the radiators 69b, 69c, and 69e in the toilet, and the tank 40 For example, when the temperature returns to 10 ° C., the temperature drops to 10 ° C. That is, the temperature of the warm water returning to the tank 40 becomes very small, and the heat pump 10 that heats the warm water from that temperature to 70 ° C., for example, can heat the warm water with very high thermal efficiency.

  Moreover, in this system, the electric heater in the toilet 69 etc. which were conventionally installed separately from the heating system can be omitted. Further, since the heating work in the toilet 69 is handled by the heat pump 10 having higher thermal efficiency than the electric heater, further energy saving can be achieved.

  The toilet radiators 69b, 69c and 69e are not only the toilet radiator 69c but also the toilet tank heat dissipating part 69b provided in the toilet tank 69a for storing the wash water, and the toilet seat provided in the toilet seat 69d. Since the heat dissipating part 69e is provided and the device is designed to promote the decrease in the temperature of the hot water, the temperature of the hot water that inevitably returns to the tank 40 is very small.

(5)
In view of the characteristics of the heat pump that the thermal efficiency improves as the temperature change range of the heating target increases, the present system further adopts a configuration in which a hot water tank internal heat exchanger 41 is installed in the tank 40. This eliminates the need for a separate water heater such as a gas water heater, and the heat pump 10 maintains high thermal efficiency.

  That is, in the present system, the heat of hot water stored in the tank 40 is deprived for heating to the indoor radiators 61a and 62a of the living rooms 61 and 62, and the heat is used for hot water supply. Specifically, a hot water tank internal heat exchanger 41 is installed in the tank 40 so that the water from the water supply source takes the heat of the hot water in the tank 40 when passing through the hot water tank internal heat exchanger 41. It is composed. Thereby, the temperature of the hot water in the tank 40 falls, and the heat pump 10 that heats the hot water from that temperature to, for example, 70 ° C. can heat the hot water with very high thermal efficiency.

(6)
Further, in this system, a part of the heated water discharged (supplied) from the hot water tank internal heat exchanger 41 in the tank 40 to the hot water supply pipe 72 is used, and the evaporator of the heat pump 10 is used by the heated water spraying device 75. The structure which sprinkles heated water on the outer surface of 14 is employ | adopted. Since the heating water is at least 40 ° C. or higher, frost attached to the evaporator 14 can be melted.

  Thus, since the defrosting of the evaporator 14 is performed by the heated water generated using the heat in the tank 40, the evaporator 14 is operated as a radiator by reversing the refrigeration cycle as in the prior art. The defrosting operation is not performed and the heat efficiency of the heat pump 10 is not deteriorated, or the frost attached to the evaporator 14 is melted by another electric heater or the like and the electric consumption is not increased. For this reason, further energy saving can be achieved in this system.

  When defrosting of the evaporator 14 is not required, the general controller 29 does not issue an instruction for spraying heated water. For this reason, the heat of the hot water in the tank 40 is not wasted.

(7)
Further, in the present system, the heated water supplied from the hot water supply tank internal heat exchanger 41 to the hot water supply pipe 72 can be further heated via the hot water supply auxiliary dedicated tank external heat exchanger 43. Specifically, when the temperature of the hot water in the tank 40 is low, the hot water supply auxiliary circulation pump 46 is used when the water cannot be sufficiently heated to a temperature suitable for hot water supply by the hot water tank internal heat exchanger 41 alone. , And the heat from the radiator 12 of the heat pump 10 is given to the heated water heated by the hot water tank internal heat exchanger 41 via the hot water auxiliary auxiliary tank external heat exchanger 43 to heat the water at an insufficient temperature. Water is heated further. Thereby, the malfunction that the hot water temperature falls below request | requirement temperature or the blank time zone which cannot supply hot water arises can be suppressed.

  In addition, in this system, the heat pump 10 supplies heat to the hot water supplied to the hot water supply pipe 72 via the hot water auxiliary auxiliary tank external heat exchanger 43 and the function of supplying heat to the hot water in the tank 40. Therefore, the running cost can be reduced as compared with the case where a dedicated electric heater or the like is used in place of the hot water supply auxiliary dedicated tank external heat exchanger 43. Moreover, the thermal efficiency of the heat pump 10 can also be improved.

<Modification>
(A)
In the above hot water circulation heating system, a radiator (toilet radiators 69b, 69c, 69e) is also provided in the toilet 69 which is not a room, and after the warm water flowing out of the tank 40 flows through the indoor radiators 61a, 62a, Although it is configured to flow through at least one of the radiators 69b, 69c, 69e in the toilet, the heat pump 10 can be operated with high thermal efficiency even if the following configuration is adopted instead of this configuration.

  Here, as shown in FIG. 10, the hot water leaving the tank 40 flows through the indoor radiators 61 a and 62 a, then flows through the window frame radiators 61 b and 62 b, and then returns to the tank 40 from the indoor hot water. A circulation path is formed. The window frame radiators 61b and 62b are formed on the window frames of the windows 65 and 66 of the building, and heat of the hot water is transferred to the air in the vicinity of the windows 65 and 66 (the air on the indoor side of the windows 65 and 66 and the windows 65 and 66). The air on the outdoor side). The window frame radiators 61b and 62b may be pipes housed inside the window frame, or may be the window frame itself that serves both for holding the glass window and for the flow of hot water. Other configurations of the hot water circulation heating system are the same as those described above with reference to FIGS. 1, 3, and 4.

  Also in this hot water circulation heating system, the hot water in the tank 40 is heated by the operation of the heat pump 10, and the hot water is heated by the operation of the indoor heating circulation pump 51 in the indoor radiators 61a and 62a and the window frame heat radiation. To the devices 61b and 62b. Then, the heat of the hot water moves to the room air in the rooms 61 and 62 and the air around the window frame radiators 61b and 62b, and the rooms 61 and 62 are heated. Then, the hot water whose temperature has decreased returns to the tank 40 again. The hot water whose temperature has been lowered is raised again by the operation of the heat pump 10.

  Then, window frame radiators 61b and 62b are installed in the window frames of the windows 65 and 66 of the building so that the hot water flowing out of the tank 40 flows through the indoor radiators 61a and 62a and then flows through the window frame radiators 61b and 62b. Therefore, for example, the hot water that enters the indoor radiators 61a and 62a at 70 ° C. and exits the indoor radiators 61a and 62a at 40 ° C. further reduces the temperature by passing through the window frame radiators 61b and 62b. When returning to the tank 40, the temperature drops to 10 ° C., for example. Then, the temperature of the warm water returning to the tank 40 becomes very small, and the heat pump 10 that heats the warm water from that temperature to, for example, 70 ° C. can heat the warm water with very high thermal efficiency.

  Further, in the case of this system, the temperature of the cold air that has conventionally come down from the windows 65 and 66 is alleviated by the heat released from the window frame radiators 61b and 62b, and the temperature drop in the living rooms 61 and 62 is suppressed. And a useful effect that temperature deviation in each part in the living rooms 61 and 62 is suppressed can be obtained.

(B)
In the above hot water circulation heating system, CO2 refrigerant is used as the refrigerant of the heat pump 10, but the present invention also applies to GWP (Global) in the hot water circulation heating system using HFC-type freon refrigerants such as R410A, R407C, and R32. This method is effective both in a hot water circulation heating system using a chlorofluorocarbon refrigerant having a Warming Potential) of 200 or less and in a hot water circulation heating system using an HC natural refrigerant such as propane or butane.

(C)
In the above hot water circulation heating system, only when necessary, the heat from the heat pump 10 is supplied to the heated water that has exited the heat exchanger 41 in the hot water supply tank that has been underheated using the heat exchanger 43 dedicated to the hot water supply auxiliary tank. Although it tries to avoid useless heat supply to the heated water (what flows to the hot water supply pipe 72), it is also considered to always use the external heat exchanger 43 dedicated to hot water supply assistance. It is done.

  For example, the capacity of the hot water supply auxiliary circulation pump 46 can be adjusted so that the amount of heat supplied from the hot water supply auxiliary tank external heat exchanger 43 to the heated water discharged from the hot water supply tank internal heat exchanger 41 can be controlled. In this case, the hot water supply auxiliary circulation pump 46 can be adjusted so that the temperature detected by the hot water supply pipe temperature sensor 72a is always substantially constant.

The figure which shows a part of structure of the warm water circulation heating system which concerns on one Embodiment of this invention. The figure which shows a part of structure of a warm water circulation heating system. The figure which shows a part of structure of a warm water circulation heating system. The control block diagram of a hot water circulation heating system. The figure which shows the flow of hot water supply control. The figure which shows the flow of a frame heat storage utilization energy saving control. The figure which shows the flow of a frame heat storage utilization energy saving control. The figure (Th diagram) which shows the heat pump cycle in case the return temperature to the tank 40 of the hot water used for heating is high. The figure (Th diagram) which shows a heat pump cycle in case the return temperature to the tank 40 of the hot water provided for heating is low. The figure which shows a part of structure of the warm water circulation heating system of a modification (A).

Explanation of symbols

10 Heat Pump 14 Evaporator 25 Circulating Pump for Hot Water Heating 29 General Controller (Control Unit)
40 Tanks 41 Heat exchanger in hot water tank (first heat exchanger for hot water supply)
43 Heat exchanger auxiliary tank external heat exchanger (second heat exchanger for hot water supply)
46 Hot water supply auxiliary circulation pump 51 Indoor heating circulation pump (circulation pump for radiator)
61a, 62a Indoor radiator (radiator)
69c Radiator in the toilet (Radiator)

Claims (7)

A hot water circulation heating system for heating by circulating hot water in a building,
A tank (40) for storing hot water;
Radiators (61a, 62a, 69c) that are arranged in the building and dissipate the heat of warm water to the air in the building;
A radiator circulation pump (51) for flowing warm water from the tank to the radiator and returning the warm water radiated by the radiator to the tank again;
A first heat exchanger for hot water supply, which is disposed in the tank, exchanges heat between water taken from a water supply source and hot water in the tank, and heats the water to be supplied to a hot water supply pipe of a building ( 41),
A second heat exchanger for hot water supply (43) disposed outside the tank and supplying heat to the water supplied to the hot water supply pipe;
A vapor compression heat pump (10) that supplies heat to the hot water in the tank and supplies heat to the water supplied to the hot water supply pipe via the second hot water supply heat exchanger (43). When,
Hot water circulation heating system equipped with. When the ability of heating the water by the first hot water supply heat exchanger is insufficient, the heat pump heats the water supplied to the hot water supply pipe via the second hot water supply heat exchanger (43). Control unit (29)
The hot water circulation heating system according to claim 1, further comprising: Circulating hot water from the tank to the heat pump and returning the hot water from the heat pump back to the tank;
A hot water supply auxiliary circulation pump (46) for circulating a fluid carrying heat from the heat pump to the hot water supply second heat exchanger between the heat pump and the hot water supply second heat exchanger;
Further comprising
The control unit activates the hot water supply auxiliary circulation pump when the ability of heating the water by the first hot water supply heat exchanger is insufficient.
The hot water circulation heating system according to claim 2. The heat pump uses carbon dioxide as a refrigerant.
The hot water circulation heating system according to any one of claims 1 to 3. The heat pump uses a fluorocarbon refrigerant as a refrigerant.
The hot water circulation heating system according to any one of claims 1 to 3. The heat pump uses a refrigerant having a GWP of 200 or less as a refrigerant,
The hot water circulation heating system according to any one of claims 1 to 3. The heat pump uses an HC refrigerant that is a natural refrigerant as a refrigerant.
The hot water circulation heating system according to any one of claims 1 to 3.

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