JP7703101B2 - Air conditioning and hot water supply systems, and collective air conditioning and hot water supply systems - Google Patents

Description

This disclosure relates to air conditioning and hot water systems and collective air conditioning and hot water systems.

For example, Patent Document 1 describes a heat pump water heater and a heat pump water heater system in which a heat medium that has received heat is compressed in a compressor to increase its temperature, and the heat is then applied to city water in a heat exchanger to provide hot water.

JP 2012-42105 A

In a heat pump water heater system like the one described above, the heat medium that receives exhaust heat from a data center or the like is circulated to supply heat to each heat pump water heater. However, because piping resistance acts within the piping through which the heat medium circulates, the pressure of the heat medium in the piping decreases the farther the piping is from the pump that pumps the heat medium. As a result, the flow rate of heat medium supplied to heat pump water heaters that are farther from the pump is smaller than that of heat pump water heaters that are closer to the pump, which can result in a decrease in heat pump capacity.

In consideration of the above circumstances, one of the objectives of this disclosure is to provide an air conditioning and hot water supply system and a collective air conditioning and hot water supply system that can maintain a substantially constant heat pump capacity regardless of the installation location of the air conditioning and hot water supply equipment.

One aspect of an air conditioning and hot water supply system according to the present disclosure includes a heat supply facility that supplies heat, and a plurality of air conditioning and hot water supply facilities that receive heat from the heat supply facility, the heat supply facility including a first circulation circuit that circulates a first heat medium, and the air conditioning and hot water supply facilities including a second circulation circuit that circulates a second heat medium, a branch pipe line connected to the first circulation circuit, a heat pump that transfers heat from the branch pipe line to the second circulation circuit, and a pressure regulator that is provided in the branch pipe line and that adjusts the pressure of the first heat medium flowing inside the branch pipe line to a predetermined pressure. the air conditioning and hot water supply equipment comprises a flow rate adjustment mechanism provided downstream of the pressure adjustment mechanism in the branch pipeline and adjusting a flow rate of the first heat medium flowing through the branch pipeline, and a control device controlling the flow rate adjustment mechanism, wherein the higher the temperature of the first heat medium flowing into the heat exchanger of the heat pump, the lower the flow rate of the first heat medium flowing through the branch pipeline, and the lower the temperature of the first heat medium flowing into the heat exchanger of the heat pump, the higher the flow rate of the first heat medium flowing through the branch pipeline .
Moreover, one aspect of an air conditioning and hot water supply system according to the present disclosure includes a heat supply facility that supplies heat, and a plurality of air conditioning and hot water supply facilities that receive heat from the heat supply facility, the heat supply facility includes a first circulation circuit that circulates a first heat medium, the air conditioning and hot water supply facility includes a second circulation circuit that circulates a second heat medium, a branch pipe line connected to the first circulation circuit, a heat pump that transfers heat from the branch pipe line to the second circulation circuit, and a pressure adjustment mechanism that is provided in the branch pipe line and adjusts the pressure of the first heat medium flowing inside the branch pipe line to a predetermined pressure, and the air conditioning and hot water supply facility includes a pressure adjustment mechanism in the branch pipe line. a flow rate adjustment mechanism provided downstream of the mechanism for adjusting a flow rate of the first heat medium circulating inside the branch pipe, and a control device for controlling the flow rate adjustment mechanism, and the heat pump comprises a third circulation circuit through which a third heat medium circulates, a heat exchanger for exchanging heat between the branch pipe and the third circulation circuit, and a compressor provided in the third circulation circuit for compressing the third heat medium, wherein the flow rate of the first heat medium flowing into the heat exchanger increases when the rotation speed of the compressor stops increasing, and the flow rate of the first heat medium flowing into the heat exchanger decreases when the rotation speed of the compressor stops decreasing.

One aspect of the collective air conditioning and hot water supply system disclosed herein comprises a second heat supply facility that supplies heat, and a plurality of air conditioning and hot water supply systems that receive heat from the second heat supply facility, at least one of the plurality of air conditioning and hot water supply systems comprising the above-described air conditioning and hot water supply system.

According to the present disclosure, heat pump capacity can be kept approximately constant regardless of the installation location of the air conditioning and hot water supply equipment.

1 is a schematic diagram showing the configuration of a collective air-conditioning and hot water supply system in embodiment 1. FIG. 1 is a schematic diagram showing the configuration of an air conditioning and hot water supply system in a first embodiment. FIG. 2 is a block diagram showing a configuration of a control device according to the first embodiment. FIG. 4 is a flowchart showing control by the control device in the first embodiment. 5 is a graph showing a relationship between a flow rate of a heat medium flowing inside a branch pipe and a temperature of the heat medium flowing into a heat exchanger on a primary side of a heat pump in the first embodiment. FIG. 11 is a schematic diagram showing the configuration of an air conditioning and hot water supply system in a second embodiment. A schematic diagram showing the configuration of a collective air-conditioning and hot water supply system in embodiment 3.

Below, an embodiment of the present disclosure will be described with reference to the drawings. Note that the scope of the present disclosure is not limited to the following embodiment, and can be modified as desired within the scope of the technical ideas of the present disclosure. Also, in the following drawings, the scale and number of each structure may differ from the scale and number of the actual structure in order to make each configuration easier to understand.

Embodiment 1.
Fig. 1 is a schematic diagram showing the configuration of a collective air-conditioning and hot water supply system 1 in embodiment 1. Fig. 1 illustrates a collective air-conditioning and hot water supply system 1 installed in a high-rise collective dwelling such as an apartment building.
The collective air conditioning and hot water system 1 shown in Figure 1 comprises a central heat supply equipment 2 (also referred to as a main heat supply equipment) that supplies heat to each floor of the apartment building, and a plurality of air conditioning and hot water systems 3 that are provided on each floor of the apartment building and receive heat from the central heat supply equipment 2.

The central heat supply facility 2 includes a heat pump 11 , a circulation circuit 12 , a pump 13 , an expansion tank 14 , and a heat exchanger 15 .
A plurality of heat pumps 11 are installed, for example, on the rooftop of an apartment building. The heat pumps 11 collect heat from the atmosphere and heat a heat medium in a pipe of a circulation circuit 12.

The circulation circuit 12 connects the heat pump 11, the pump 13, the expansion tank 14, and the heat exchanger 15. The piping of the circulation circuit 12 is filled with a heat medium. An example of a heat medium is water. The pump 13 circulates the heat medium in the piping of the circulation circuit 12, and supplies the heat medium heated by the heat pump 11 to the heat exchanger 15.

For example, the heat medium is at 20°C before being heated by the heat pump 11, and at 25°C after being heated. The expansion tank 14 absorbs a portion of the heat medium, the volume of which has increased due to the rise in temperature, from the circulation circuit 12. The expansion tank 14 is, for example, a sealed tank. Since the heat medium in the sealed tank does not come into contact with the atmosphere, using a sealed tank can prevent the heat medium in the sealed tank from evaporating into the atmosphere and oxidizing.

Heat exchangers 15 are installed on each floor of the apartment building. Heat exchangers 15 are, for example, plate heat exchangers. The heat medium dissipates heat in the heat exchanger 15 on each floor, and the air conditioning and hot water supply system 3 on each floor receives the heat. For example, the heat medium is at 25°C before dissipating heat in the heat exchanger 15, and is at 20°C after dissipating heat.

An air conditioning and hot water supply system 3 is provided on each floor of the apartment building. In other words, the air conditioning and hot water supply systems 3 are installed in a line in the vertical direction. On each floor, multiple dwelling units are lined up horizontally, and an air conditioning and hot water supply equipment 30 is installed corresponding to each dwelling unit.

The air conditioning and hot water system 3 includes a heat supply facility 20 (also called a branch heat supply facility) that relays heat received from the central heat supply facility 2 and supplies it to each dwelling unit, and a number of air conditioning and hot water facilities 30 that receive heat from the heat supply facility 20. The heat supply facility 20 includes a circulation circuit 21, a pump 22, and an expansion tank 23.

The circulation circuit 21 connects the pump 22, the expansion tank 23, and the air conditioning and hot water supply equipment 30. The piping of the circulation circuit 21 is filled with a heat medium. An example of a heat medium is water. The pump 22 circulates the heat medium in the piping of the circulation circuit 21, and supplies the heat medium heated in the heat exchanger 15 to the air conditioning and hot water supply equipment 30.

For example, the heat medium is at 15°C before being heated by the heat exchanger 15, and at 20°C after being heated. The expansion tank 23 absorbs a portion of the heat medium, the volume of which has increased due to the rise in temperature, from the circulation circuit 21. The expansion tank 23 is, for example, a sealed tank. Since the heat medium in the sealed tank does not come into contact with the atmosphere, using a sealed tank can prevent the heat medium in the sealed tank from evaporating into the atmosphere and being oxidized.

FIG. 2 is a schematic diagram showing the configuration of air conditioning and hot water supply equipment 30 in the first embodiment.
The air conditioning and hot water supply equipment 30 shown in Fig. 2 is installed in a dwelling unit 5. Note that the air conditioning and hot water supply equipment 30 may be installed outside the dwelling unit 5 as long as it is installed for each dwelling unit 5. An air conditioning terminal 6 and a hot water supply terminal 7 are installed in the dwelling unit 5.

The air conditioning terminal 6 includes, for example, a radiator panel, and conditions the interior of the dwelling unit 5 using the heat of hot water or water supplied from the air conditioning and hot water supply equipment 30. The hot water supply terminal 7 includes, for example, a shower, and supplies hot water supplied from the air conditioning and hot water supply equipment 30. Note that at least one of the air conditioning terminal 6 and the hot water supply terminal 7 may be connected to the air conditioning and hot water supply equipment 30, either singly or in multiples.

The air conditioning and hot water supply system 30 includes a transformer 31 , a control device 32 , a tank 33 , a circulation circuit 40 , a branch pipe 50 , and a heat pump 60 .
The tank 33 includes a tank heat exchanger 43a therein and stores water. Hereinafter, the water stored in the tank 33 is referred to as tank water. The tank 33 is connected to the hot water supply terminal 7. The circulation circuit 40 includes an air conditioning circuit 42 connected to the air conditioning terminal 6 and a hot water supply circuit 43 connected to the tank heat exchanger 43a.

The piping of the circulation circuit 40 is filled with a heat medium. One example of the heat medium is water. The circulation circuit 40 is provided with a pump 41 that circulates the heat medium, and a flow path switching mechanism 44 that switches the circulation path of the heat medium to the air conditioning circuit 42 or the hot water supply circuit 43. The flow path switching mechanism 44 is, for example, a three-way switching valve, which communicates two of the three flow paths and blocks one.

Specifically, the flow path switching mechanism 44 can communicate with the air conditioning circuit 42 and block the hot water supply circuit 43. In this case, the heat medium in the piping of the circulation circuit 40 circulates in the order of the heat exchanger 64 on the secondary side of the heat pump 60, the flow path switching mechanism 44, the air conditioning circuit 42, and the air conditioning terminal 6. The heat medium dissipates heat in the air conditioning terminal 6 and heats the inside of the dwelling unit 5.

The flow path switching mechanism 44 can also communicate with the hot water supply circuit 43 and block the air conditioning circuit 42. In this case, the heat medium in the piping of the circulation circuit 40 circulates through the heat exchanger 64 on the secondary side of the heat pump 60, the flow path switching mechanism 44, the hot water supply circuit 43, and the tank heat exchanger 43a in that order. The heat medium dissipates heat in the tank heat exchanger 43a and heats the tank water. The heated tank water is used by the hot water supply terminal 7.

The circulation circuit 40 is provided with a temperature sensor 45. The temperature sensor 45 is disposed in the circulation circuit 40 downstream of the heat exchanger 64 on the secondary side of the heat pump 60 and upstream of the flow path switching mechanism 44. The temperature sensor 45 measures the temperature (outlet hot water temperature) of the heat medium flowing out from the heat exchanger 64 on the secondary side of the heat pump 60.

The heat pump 60 transfers heat from the branch pipe 50 connected to the circulation circuit 21 of the heat supply equipment 20 to the circulation circuit 40. The heat pump 60 includes a circulation circuit 61, a compressor 62, an expansion mechanism 63, a secondary side heat exchanger 64, a primary side heat exchanger 65, and a flow path switching mechanism 66.

The circulation circuit 61 connects a compressor 62, an expansion mechanism 63, a secondary heat exchanger 64, a primary heat exchanger 65, and a flow path switching mechanism 66. The piping of the circulation circuit 61 is filled with a heat medium. An example of a heat medium is difluoromethane or propane. The compressor 62 compresses and discharges the heat medium in the piping of the circulation circuit 61, circulating the heat medium.

The primary-side heat exchanger 65 is thermally connected to the circulation circuit 21 of the heat supply equipment 20 via a branch pipe 50. The secondary-side heat exchanger 64 is thermally connected to the circulation circuit 40 of the air-conditioning terminal 6 and the hot water supply terminal 7. The expansion mechanism 63 is, for example, an expansion valve, and expands the heat medium that has passed through the secondary-side heat exchanger 64 to lower the temperature.

Specifically, the heat medium in the piping of the circulation circuit 61 dissipates heat in the secondary heat exchanger 64. The heat medium that has dissipated heat is cooled as it passes through the expansion mechanism 63, and flows into the primary heat exchanger 65. The heat medium that has flowed into the primary heat exchanger 65 absorbs heat from the branch pipe 50 in the primary heat exchanger 65. The heat-absorbing heat medium flows back into the compressor 62.

The heat pump 60 repeats this cycle to transfer heat from the branch pipe 50 to the circulation circuit 40. An example of the temperature of the heat medium in the piping of the branch pipe 50 is 20°C before heat is released in the primary heat exchanger 65, and 15°C after heat is released. An example of the temperature of the heat medium in the circulation circuit 40 is 45°C before heat is absorbed in the secondary heat exchanger 64, and 50°C after heat is absorbed. The amount of heat (watts) that the heat pump 60 provides to the circulation circuit 40 from the branch pipe 50 is called the heat pump capacity.

The heat pump capacity can be changed by changing the circulation flow rate of the heat medium in the circulation circuit 61. Specifically, the circulation flow rate of the heat medium in the circulation circuit 61 (heat pump capacity) can be changed by changing at least one of the rotation speed of the compressor 62 and the opening degree of the expansion mechanism 63. By changing the heat pump capacity, the outlet hot water temperature can be increased or decreased.

The flow path switching mechanism 66 is, for example, a four-way switching valve, and switches the flow path of the circulation circuit 61 to form a heating circuit and a cooling circuit. The heating circuit is a circuit that transfers heat from the branch pipe 50 to the circulation circuit 40. The cooling circuit is a circuit that transfers heat from the circulation circuit 40 to the branch pipe 50. In the following explanation, an example will be given in which the flow path switching mechanism 66 forms a heating circuit.

The branch pipe 50 connects the circulation circuit 21 of the heat supply equipment 20 to the primary heat exchanger 65 of the heat pump 60. The branch pipe 50 is connected to the outgoing side of the circulation circuit 21 via a connection point 50a provided in the dwelling unit 5, and is connected to the upstream side of the primary heat exchanger 65 via a connection point 50b provided in the air conditioning and hot water supply equipment 30.

In addition, the branch pipe 50 is connected to the return side of the circulation circuit 21 via a connection point 50d provided in the dwelling unit 5, and is connected to the downstream side of the primary heat exchanger 65 via a connection point 50c provided in the air conditioning and hot water supply equipment 30. In other words, the branch pipe 50 connects the outward and return sides of the circulation circuit 21, and forms a flow path that passes through the primary heat exchanger 65 of the air conditioning and hot water supply equipment 30.

The branch pipe 50 is provided with a pressure adjustment mechanism 51 and a flow rate adjustment mechanism 52. The pressure adjustment mechanism 51 adjusts the pressure of the heat medium flowing inside the branch pipe 50 to a predetermined pressure. The predetermined pressure is a pressure at which the differential pressure of the heat medium before and after the pressure adjustment mechanism 51 is approximately constant. The pressure adjustment mechanism 51 is, for example, a differential pressure adjustment valve equipped with a spring, and reduces the pressure of the heat medium flowing in with the spring to adjust the differential pressure of the heat medium before and after the pressure adjustment mechanism 51 to be approximately constant. Note that the pressure adjustment mechanism 51 may be reduced by an elastic member such as rubber, not limited to a spring, as long as it can reduce the pressure of the heat medium flowing inside the branch pipe 50, or may reduce the pressure using hydraulic pressure or air pressure.

The flow rate adjustment mechanism 52 is provided downstream of the pressure adjustment mechanism 51 in the branch pipe 50, and adjusts the flow rate of the heat medium flowing inside the branch pipe 50. The flow rate adjustment mechanism 52 has, for example, an on-off valve, and changes the opening of the branch pipe 50 through which the heat medium flows to change the flow rate of the heat medium. The flow rate of the heat medium flowing through the flow rate adjustment mechanism 52 and the branch pipe 50 decreases as the opening of the branch pipe 50 becomes smaller, and increases as the opening of the branch pipe 50 becomes larger.

The flow rate adjustment mechanism 52 further includes an electric motor and a communication device. The electric motor is, for example, a stepping motor driven by 24 V, and drives the above-mentioned on-off valve to change the opening degree of the branch pipe 50. The communication device communicates with the control device 32. The communication device receives a target opening degree, which is a target value for the opening degree of the branch pipe 50, from the control device 32.

The flow rate adjustment mechanism 52 drives the electric motor so that the opening of the on-off valve becomes the target opening. The transformer 31 is connected to a power source and supplies power to the flow rate adjustment mechanism 52. The transformer 31 changes the voltage, for example, by electromagnetic induction. The voltage of the power source is, for example, 240 V, and the transformer 31 transforms the voltage of the power source to 24 V, which is the drive voltage of the flow rate adjustment mechanism 52.

A temperature sensor 53 is provided in the branch pipe 50. The temperature sensor 53 is disposed in the branch pipe 50 downstream of the flow rate adjustment mechanism 52 and upstream of the heat exchanger 65 on the primary side of the heat pump 60. The temperature sensor 53 measures the temperature of the heat medium flowing into the heat exchanger 65 on the primary side of the heat pump 60.

FIG. 3 is a block diagram showing a configuration of the control device 32 in the first embodiment.
3 , the control device 32 is connected to the above-mentioned temperature sensors 45, 53 and receives measurement results from the temperature sensors 45, 53. The control device 32 is also connected to the above-mentioned compressor 62, expansion mechanism 63, and flow path switching mechanism 66, and controls switching between the heating circuit and the cooling circuit and the heat pump capacity of the heat pump 60.

The control device 32 is also connected to the pump 41 and flow path switching mechanism 44 described above, and controls the switching between the air conditioning circuit 42 and the hot water supply circuit 43, and the circulation or stopping of the heat medium to the air conditioning circuit 42 and the hot water supply circuit 43. The control device 32 is also connected to the flow rate adjustment mechanism 52 described above, and adjusts the flow rate of the heat medium circulating inside the branch pipe 50, and controls the flow rate of the heat medium supplied to the heat exchanger 65 on the primary side of the heat pump 60.

The control device 32 changes the target opening of the branch pipe 50 based on the temperature measured by a temperature sensor 53 provided in the branch pipe 50. When the temperature measured by the temperature sensor 53 increases, the control device 32 decreases the target opening of the branch pipe 50, and when the temperature measured by the temperature sensor 53 decreases, the control device 32 increases the target opening of the branch pipe 50. The target opening of the branch pipe 50 can be selected, for example, between 0% (fully closed) and 100% (fully open).

The control device 32 also has a target temperature as a control parameter. The target temperature is a target value for the hot water outlet temperature, and is set to, for example, 50°C. The target temperature is usually set based on the temperature that the resident of the dwelling unit 5 wishes to use at the hot water supply terminal 7 or air conditioning terminal 6. As will be described in more detail later, the control device 32 changes the rotation speed of the compressor 62, the opening of the expansion mechanism 63, and the target opening of the branch pipe 50 so that the hot water outlet temperature becomes the target temperature.

The control device 32 also has, as control parameters, an upper limit rotation speed, which is the upper limit of the rotation speed of the compressor 62, and a lower limit rotation speed, which is the lower limit of the rotation speed of the compressor 62. The control device 32 increases the target opening of the branch pipe 50 when the rotation speed of the compressor 62 reaches the upper limit rotation speed, and decreases the target opening of the branch pipe 50 when the rotation speed of the compressor 62 reaches the lower limit rotation speed. The control device 32 may increase (or decrease) the target opening of the branch pipe 50 immediately before the rotation speed of the compressor 62 reaches the upper limit (or lower limit) rotation speed.

Furthermore, the control device 32 has, as control parameters, an upper limit opening, which is the upper limit of the target opening of the branch pipeline 50, and a lower limit opening, which is the lower limit of the target opening of the branch pipeline 50. The upper limit opening and the lower limit opening may be set values selected between 0% (fully closed) and 100% (fully open), or the upper limit opening may be 100% (fully open) and the lower limit opening may be 0% (fully closed).

4 is a flowchart showing the control of control device 32 in embodiment 1. In the following description, control device 32 performs control so that the outlet heated water temperature becomes a target temperature.
First, the control device 32 compares the measurement result (outlet hot water temperature) of the temperature sensor 45 with the target temperature (step S1).

If the hot water outlet temperature is lower than the target temperature, the control device 32 increases the rotation speed of the compressor 62 to raise the hot water outlet temperature (step S2). Next, the control device 32 compares the rotation speed of the compressor 62 with the upper limit rotation speed (step S3). If the rotation speed of the compressor 62 has not reached the upper limit rotation speed, the process returns to step S1 and compares the hot water outlet temperature with the target temperature.

On the other hand, if the rotational speed of the compressor 62 reaches the upper limit before the hot water outlet temperature reaches the target temperature, the control device 32 increases the target opening of the branch pipe 50 as the next step to increase the hot water outlet temperature (step S4). Next, the control device 32 compares the target opening of the branch pipe 50 with the upper limit opening (step S5).

If the target opening of the branch pipe 50 has not reached the upper limit, the process returns to step S1, and the hot water outlet temperature is compared with the target temperature. On the other hand, if the target opening of the branch pipe 50 reaches the upper limit before the hot water outlet temperature reaches the target temperature, the control device 32 ends control.

If the determination in step S1 is NO, the control device 32 compares the outlet hot water temperature with the target temperature (step S6). If the outlet hot water temperature is higher than the target temperature, the control device 32 reduces the rotation speed of the compressor 62 to lower the outlet hot water temperature (step S7). Next, the control device 32 compares the rotation speed of the compressor 62 with the lower limit rotation speed (step S8).

If the rotational speed of the compressor 62 is not at the lower limit, the process returns to step S1, and the hot water outlet temperature is compared with the target temperature. On the other hand, if the rotational speed of the compressor 62 reaches the lower limit before the hot water outlet temperature falls to the target temperature, the control device 32 reduces the target opening of the branch pipe 50 as the next step in lowering the hot water outlet temperature (step S9).

Next, the control device 32 compares the target opening of the branch pipe 50 with the lower limit opening (step S10). If the target opening of the branch pipe 50 has not reached the lower limit opening, the process returns to step S1, and the outlet hot water temperature is compared with the target temperature. On the other hand, if the target opening of the branch pipe 50 reaches the lower limit opening before the outlet hot water temperature drops to the target temperature, the control device 32 ends control.
In this manner, the control device 32 controls the outlet heated water temperature to the target temperature.

In the above-mentioned air conditioning and hot water supply system 3, as shown in FIG. 1, the heat medium circulating inside the circulation circuit 21 of the heat supply equipment 20 is subjected to piping resistance, so the pressure of the heat medium decreases as the distance from the pump 22 increases. Therefore, even if the piping diameter of the circulation circuit 21 is constant, the flow rate of the heat medium is likely to increase in the air conditioning and hot water supply equipment 30 that is closer to the pump 22, and the flow rate of the heat source medium is likely to decrease in the air conditioning and hot water supply equipment 30 that is farther from the pump 22. The heat pump capacity of each air conditioning and hot water supply equipment 30 varies depending on the flow rate of the heat medium, and the capacity increases when the flow rate of the heat medium is high, and the capacity decreases when the flow rate is low. Therefore, the heat pump capacity of each air conditioning and hot water supply equipment 30 differs depending on its installation position.

2, the air conditioning and hot water supply system 3 of the above-mentioned embodiment 1 is provided with a pressure adjustment mechanism 51 in the branch pipe 50 connected to the circulation circuit 21, which adjusts the pressure of the heat medium flowing through the branch pipe 50 to a predetermined pressure. With this configuration, the differential pressure of the heat medium before and after the pressure adjustment mechanism 51 of each air conditioning and hot water supply equipment 30 can be adjusted to a substantially constant value, so that the flow rate of the heat medium flowing into the air conditioning and hot water supply equipment 30 is substantially constant regardless of the distance from the pump 22 to the air conditioning and hot water supply equipment 30, that is, regardless of the location of the dwelling unit 5 of the apartment building, and the heat pump capacity of the air conditioning and hot water supply equipment 30 can be made substantially constant.

Thus, according to the air conditioning and hot water supply system 3 of the above-mentioned embodiment 1, the system includes a heat supply equipment 20 that supplies heat and a plurality of air conditioning and hot water supply equipment 30 that receive heat from the heat supply equipment 20, the heat supply equipment 20 includes a circulation circuit 21 (first circulation circuit) that circulates a heat medium (first heat medium), and the air conditioning and hot water supply equipment 30 includes a circulation circuit 40 (second circulation circuit) that circulates a heat medium (second heat medium), a branch pipe 50 connected to the circulation circuit 21, a heat pump 60 that transfers heat from the branch pipe 50 to the circulation circuit 40, and a pressure adjustment mechanism 51 that is provided in the branch pipe 50 and adjusts the pressure of the heat medium flowing inside the branch pipe 50 to a predetermined pressure. With this configuration, the heat pump capacity can be made approximately constant regardless of the installation position of the air conditioning and hot water supply equipment 30.

According to the first embodiment, the air conditioning and hot water supply equipment 30 includes a flow rate adjustment mechanism 52 that is provided downstream of the pressure adjustment mechanism 51 in the branch pipe 50 and adjusts the flow rate of the heat medium flowing inside the branch pipe 50, and a control device 32 that controls the flow rate adjustment mechanism 52. The control device 32 changes the target opening of the branch pipe 50 based on the temperature measured by the temperature sensor 53. The flow rate adjustment mechanism 52 drives the electric motor so that the opening rate of the opening and closing valve becomes the target opening rate. This operation allows the control device 32 to control the opening rate of the opening and closing valve of the flow rate adjustment mechanism 52. According to this configuration, the pressure adjustment mechanism 51 adjusts the differential pressure upstream of the flow rate adjustment mechanism 52, so when the flow rate adjustment mechanism 52 changes the opening rate of the branch pipe 50, the relationship between the opening rate of the branch pipe 50 and the flow rate of the heat medium is stable regardless of the distance from the pump 22 to the air conditioning and hot water supply equipment 30, that is, regardless of the position of the dwelling unit 5 of the apartment building, and the same opening rate results in the same flow rate. Therefore, the heat pump capacity of the air conditioning and hot water supply equipment 30 remains approximately constant.

According to the first embodiment, the flow rate adjustment mechanism 52 reduces the flow rate of the heat medium flowing through the branch pipe 50 as the temperature of the heat medium flowing into the heat exchanger 65 on the primary side of the heat pump 60 increases, and increases the flow rate of the heat medium flowing through the branch pipe 50 as the temperature of the heat medium flowing into the heat exchanger 65 on the primary side of the heat pump 60 decreases. As a result, the higher the temperature of the heat medium flowing into the heat exchanger 65 on the primary side, the lower the flow rate of the heat medium, so that excess heat pump capacity can be suppressed. Also, according to this configuration, the lower the temperature of the heat medium flowing into the heat exchanger 65 on the primary side, the higher the flow rate of the heat medium, so that insufficient heat pump capacity can be suppressed.

Specifically, according to the first embodiment, the air conditioning and hot water supply equipment 30 is provided with a temperature sensor 53 that is provided in the branch pipe 50 and measures the temperature of the heat medium flowing into the heat exchanger 65 on the primary side of the heat pump 60, and the control device 32 controls the flow rate adjustment mechanism 52 based on the temperature measured by the temperature sensor 53. In other words, the control device 32 changes the target opening degree of the branch pipe 50 based on the temperature measured by the temperature sensor 53. The flow rate adjustment mechanism 52 drives the electric motor so that the opening degree of the opening and closing valve becomes the target opening degree. This operation allows the control device 32 to control the opening degree of the opening and closing valve of the flow rate adjustment mechanism 52. According to this configuration, the amount of heat of the heat medium supplied to the heat pump 60 can be adjusted to expand the range of control of the hot water temperature.

Fig. 5 is a graph showing the relationship between the flow rate of the heat medium flowing through the branch pipe 50 in the first embodiment and the temperature of the heat medium flowing into the heat exchanger 65 on the primary side of the heat pump 60. Note that the graph shown in Fig. 5 illustrates a case where the temperature of the heat medium flowing into the heat exchanger 65 on the primary side of the heat pump 60 is 20°C and the flow rate of the heat medium is 10 L/min.
As shown in Fig. 5, when the temperature of the heat medium flowing through the inside of the branch pipe 50 increases, the flow rate of the heat medium flowing into the heat exchanger 65 on the primary side of the heat pump 60 decreases. When the temperature of the heat medium flowing through the inside of the branch pipe 50 decreases, the flow rate of the heat medium flowing into the heat exchanger 65 on the primary side of the heat pump 60 increases. When the number of revolutions of the compressor 62 reaches the upper limit rotational speed when the temperature of the heat medium does not change at 20°C, that is, when the rotational speed of the compressor 62 does not increase, the flow rate of the heat medium flowing into the heat exchanger 65 on the primary side of the heat pump 60 increases. When the temperature of the heat medium does not change at 20°C, when the number of revolutions of the compressor 62 reaches the lower limit rotational speed, that is, when the rotational speed of the compressor does not decrease, the flow rate of the heat medium flowing into the heat exchanger 65 on the primary side of the heat pump 60 decreases.

The heat pump capacity increases as the temperature of the heat medium flowing into the primary heat exchanger 65 increases and as the flow rate of the heat medium flowing into the primary heat exchanger 65 increases. The heat pump capacity decreases as the temperature of the heat medium flowing into the primary heat exchanger 65 decreases and as the flow rate of the heat medium flowing into the primary heat exchanger 65 decreases.

According to the first embodiment, the control device 32 decreases the target opening of the branch pipe 50 when the temperature measured by the temperature sensor 53 increases, and increases the target opening of the branch pipe 50 when the temperature measured by the temperature sensor 53 decreases. According to this configuration, the higher the temperature of the heat medium flowing into the primary heat exchanger 65, the smaller the flow rate of the heat medium, so that excess heat pump capacity can be suppressed. Also, according to this configuration, the lower the temperature of the heat medium flowing into the primary heat exchanger 65, the larger the flow rate of the heat medium, so that insufficient heat pump capacity can be suppressed.

According to the first embodiment, the heat pump 60 includes a circulation circuit 61 (third circulation circuit) in which a heat medium (third heat medium) circulates, a heat exchanger 65 that exchanges heat between the branch pipe 50 and the circulation circuit 61, and a compressor 62 that is provided in the circulation circuit 61 and compresses the heat medium. The flow rate adjustment mechanism 52 increases the flow rate of the heat medium flowing into the heat exchanger 65 when the rotation speed of the compressor 62 stops increasing, and decreases the flow rate of the heat medium flowing into the heat exchanger 65 when the rotation speed of the compressor 62 stops decreasing. As a result, for example, when the rotation speed of the compressor 62 is increased and the heat pump capacity is increased to the upper limit rotation speed of the compressor 62, the flow rate of the supplied heat medium further increases, so that the heat pump capacity can be increased to a wider range than the capacity adjustment by the compressor 62. In addition, for example, when the rotation speed of the compressor 62 is reduced and the heat pump capacity is lowered to the lower limit rotation speed of the compressor 62, the flow rate of the heat medium supplied is further reduced, so that the heat pump capacity can be reduced to a wider range than the capacity adjustment by the compressor 62.

Specifically, according to the first embodiment, the control device 32 controls the flow rate adjustment mechanism 52 based on the rotation speed of the compressor 62. That is, when the rotation speed of the compressor 62 reaches the upper limit, the control device 32 increases the target opening of the branch pipe 50, and when the rotation speed of the compressor 62 reaches the lower limit, the control device 32 decreases the target opening of the branch pipe 50. The flow rate adjustment mechanism 52 drives the electric motor so that the opening of the opening/closing valve becomes the target opening. This operation allows the control device 32 to control the opening of the opening/closing valve of the flow rate adjustment mechanism 52. According to this configuration, the amount of heat of the heat medium supplied to the heat pump 60 can be adjusted to expand the adjustment range of the heat pump capacity to a range wider than the adjustment range of the heat pump capacity by the compressor 62.

According to the first embodiment, the control device 32 increases the target opening of the branch pipe 50 when the rotation speed of the compressor 62 reaches the upper limit rotation speed, and decreases the target opening of the branch pipe 50 when the rotation speed of the compressor 62 reaches the lower limit rotation speed. For example, when the rotation speed of the compressor 62 is increased and the heat pump capacity is increased to the upper limit rotation speed of the compressor 62, the flow rate of the heat medium supplied further increases, so that the heat pump capacity can be increased to a wider range than the capacity adjustment of the compressor 62. Also, for example, when the rotation speed of the compressor 62 is decreased and the heat pump capacity is reduced to the lower limit rotation speed of the compressor 62, the flow rate of the heat medium supplied further decreases, so that the heat pump capacity can be reduced to a wider range than the capacity adjustment of the compressor 62.

The target temperature is usually set by the resident of the dwelling unit 5 at their own preferred temperature, so the heat pump capacity required for each dwelling unit 5 differs. In other words, the air conditioning and hot water supply system 30 can adjust the heat pump capacity individually for each dwelling unit 5 according to the set value of the target temperature for each dwelling unit.

According to the first embodiment, the air conditioning and hot water supply equipment 30 is equipped with a transformer 31 that is connected to a power source and supplies power to the flow rate adjustment mechanism 52. With this configuration, the voltage of the power source can be changed to the voltage required for the motor of the flow rate adjustment mechanism 52. Therefore, in the dwelling unit 5, there is no need to install electrical wiring of a voltage different from that of the power source, which reduces the amount of construction work.

Furthermore, the collective air conditioning and hot water supply system 1 of the first embodiment includes a central heat supply facility 2 (second heat supply facility) that supplies heat, and a plurality of air conditioning and hot water supply systems 3 that receive heat from the central heat supply facility 2, and at least one of the plurality of air conditioning and hot water supply systems 3 (all in the first embodiment) includes an air conditioning and hot water supply facility 30 that includes the above-mentioned pressure adjustment mechanism 51. With this configuration, even when the system is installed in a large-scale collective housing complex, the heat pump capacity can be kept approximately constant regardless of the installation location of the air conditioning and hot water supply facility 30.

According to the first embodiment, the multiple air conditioning and hot water supply systems 3 are installed vertically side by side. With this configuration, even when the system is installed in a high-rise apartment building, the heat pump capacity can be kept substantially constant regardless of the installation position of the air conditioning and hot water supply equipment 30.

Embodiment 2.
Fig. 6 is a schematic diagram showing the configuration of an air-conditioning and hot water supply system 30 according to embodiment 2. In the following description, the same components as those in the above-described embodiment may be denoted by the same reference numerals as appropriate and the description thereof may be omitted.

6 includes a pressure opening adjustment unit 34 having a pressure adjustment mechanism 51 and a flow rate adjustment mechanism 52, and an air conditioning hot water supply unit 35 having a heat pump 60 and a circulation circuit 40. The air conditioning hot water supply unit 35 further includes a transformer 31, a control device 32, a tank 33, etc.

The branch pipe 50 connects the pressure opening adjustment unit 34 and the air conditioning hot water supply unit 35. By adjusting the length of the branch pipe 50 connecting the pressure opening adjustment unit 34 and the air conditioning hot water supply unit 35, the placement of the pressure opening adjustment unit 34 and the air conditioning hot water supply unit 35 can be adjusted to any position for each dwelling unit 5. Thus, according to the second embodiment, the freedom of installation of the air conditioning hot water supply equipment 30 is improved.

Embodiment 3.
Fig. 7 is a schematic diagram showing the configuration of a collective air-conditioning and hot water supply system 1 in embodiment 3. In the following description, the same components as those in the above-mentioned embodiment may be appropriately denoted by the same reference numerals and description thereof may be omitted.

7, the collective air conditioning and hot water supply system 1 is provided with a pressure adjustment mechanism 25 in each of a plurality of branch pipes 24 that connect the circulation circuit 12 of the central heat supply facility 2 to the heat exchangers 15 on each floor. The branch pipes 24 are connected to the outward side of the circulation circuit 12 via connection point 24b, and are connected to the return side of the circulation circuit 12 via connection point 24a.

The pressure adjustment mechanism 25 adjusts the pressure of the heat medium flowing inside the branch pipe 24 to a predetermined pressure. The pressure adjustment mechanism 25 is, for example, a differential pressure adjustment valve equipped with a spring, and reduces the pressure of the inflowing heat medium with the spring to adjust the differential pressure of the heat medium before and after the pressure adjustment mechanism 51 to be approximately constant. The predetermined pressure is a pressure at which the differential pressure of the heat medium before and after the pressure adjustment mechanism 51 is approximately constant. Note that the pressure adjustment mechanism 25 is not limited to a spring, and may reduce the pressure using an elastic member such as rubber, or may reduce the pressure using hydraulic pressure or air pressure, as long as it can reduce the pressure of the heat medium flowing inside the branch pipe 24.

The heat medium in the circulation circuit 12 is subjected to a hydrostatic head due to the difference in elevation, so the higher the floor, the lower the heat medium pressure, and the lower the floor, the higher the heat medium pressure. According to the above-mentioned third embodiment, the branch pipes 24 connected to the heat exchangers 15 on each floor are provided with pressure adjustment mechanisms 25, so that the flow rate of the heat medium flowing into the air conditioning and hot water supply systems 3 on each floor can be made approximately constant, regardless of the difference in elevation. Therefore, the capacity of the air conditioning and hot water supply systems 3 on each floor can be made approximately constant.

Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the configurations of the above-described embodiments, and the following configurations and methods may also be adopted.

Each air conditioning and hot water equipment 30 (each dwelling unit 5) of the air conditioning and hot water system 3 does not have to be installed on the same floor, but may be installed across several floors.

A single apartment building may be equipped with multiple collective air conditioning and hot water systems 1.

The central heat supply facility 2 is equipped with a heat pump 11 that collects heat from the atmosphere, but the heat source for heating the heat medium may be a gas or kerosene boiler. The heat pump 11 may also be replaced with a heat exchanger so that the heat medium can be heated with heat generated at waste incineration facilities, power plants, data centers, etc.

The dwelling unit 5 is an example of a heat utilization space that utilizes heat in the collective air conditioning and hot water supply system 1, and may be not only a residence but also a commercial store or office space.

The pressure adjustment mechanism 51, flow rate adjustment mechanism 52, and air conditioning and hot water equipment 30 may be installed in each dwelling unit 5, and may be located within the living space of each dwelling unit 5 (inside the entrance hall), or outside the living space, such as in a pipe shaft or meter box.

The pressure adjustment mechanism 51 and the flow rate adjustment mechanism 52 may be installed downstream of the heat exchanger 65 on the primary side of the heat pump 60 in the branch pipe 50. The flow rate adjustment mechanism 52 may be installed downstream of the pressure adjustment mechanism 51.

The air conditioning and hot water supply unit 35 may further be composed of two units: a hot water supply circuit unit and an air conditioning circuit unit.

The tank heat exchanger 43a may be installed outside the tank 33. In that case, a tank circulation pump can be installed between the tank 33 and the tank heat exchanger 43a to guide the tank water to the tank heat exchanger 43a.

The control device 32 may be configured as two control devices: a first control device that controls the flow control mechanism 52 based on the temperature measured by the temperature sensor 53, and a second control device that controls the flow control mechanism 52 based on the rotation speed of the compressor 62.

The configurations and methods described in this specification can be combined as appropriate within the limits that do not contradict each other.

1... collective air conditioning and hot water supply system, 2... central heat supply equipment (second heat supply equipment), 3... air conditioning and hot water supply system, 5... dwelling unit, 6... air conditioning terminal, 7... hot water supply terminal, 11... heat pump, 12... circulation circuit, 13... pump, 14... expansion tank, 15... heat exchanger, 20... heat supply equipment, 21... circulation circuit (first circulation circuit), 22... pump, 23... expansion tank, 24... branch pipe line, 24a... connection point, 24b... connection point, 25... pressure adjustment mechanism, 30... air conditioning and hot water supply equipment, 31... transformer, 32... control device, 33... tank, 34... pressure opening adjustment Adjusting unit, 35...air conditioning and hot water supply unit, 40...circulation circuit (second circulation circuit), 41...pump, 42...air conditioning circuit, 43...hot water supply circuit, 43a...tank heat exchanger, 44...flow path switching mechanism, 45...temperature sensor, 50...branch pipe, 50a...connection point, 50b...connection point, 50c...connection point, 50d...connection point, 51...pressure adjustment mechanism, 52...flow rate adjustment mechanism, 53...temperature sensor, 60...heat pump, 61...circulation circuit (third circulation circuit), 62...compressor, 63...expansion mechanism, 64...heat exchanger, 65...heat exchanger, 66...flow path switching mechanism

Claims (11)

A heat supply facility that supplies heat;
a plurality of air conditioning and hot water supply facilities that receive heat from the heat supply facility;
The heat supply facility includes:
A first circulation circuit for circulating a first heat medium,
The air conditioning and hot water supply equipment includes:
a second circulation circuit for circulating a second heat medium;
a branch line connected to the first circulation circuit;
a heat pump that transfers heat from the branch pipe to the second circulation circuit;
a pressure adjustment mechanism that is provided in the branch pipe and adjusts a pressure of the first heat medium flowing through the branch pipe to a predetermined pressure ,
The air conditioning and hot water supply equipment includes:
a flow rate adjustment mechanism provided in the branch pipe downstream of the pressure adjustment mechanism and adjusting a flow rate of the first heat medium flowing through the branch pipe;
A control device for controlling the flow rate adjustment mechanism,
an air conditioning and hot water supply system, wherein the higher the temperature of the first heat medium flowing into the heat exchanger of the heat pump, the smaller the flow rate of the first heat medium circulating inside the branch pipe, and the lower the temperature of the first heat medium flowing into the heat exchanger of the heat pump, the larger the flow rate of the first heat medium circulating inside the branch pipe . The air conditioning and hot water supply equipment includes:
a temperature sensor provided in the branch pipe for measuring a temperature of the first heat medium flowing into a heat exchanger of the heat pump;
The air conditioning and hot water supply system according to claim 1 , wherein the control device controls the flow rate adjustment mechanism based on a temperature measured by the temperature sensor. The control device includes:
When the temperature measured by the temperature sensor increases, the target opening degree of the branch pipe is decreased;
The air conditioning and hot water supply system according to claim 2 , wherein the target opening degree of the branch pipe is increased when the temperature measured by the temperature sensor decreases. The heat pump comprises:
a third circulation circuit in which a third heat medium circulates;
a heat exchanger for exchanging heat between the branch pipe and the third circulation circuit;
a compressor provided in the third circulation circuit and configured to compress the third heat medium,
4. The air conditioning and hot water supply system according to claim 1, wherein the flow rate of the first heat medium flowing into the heat exchanger increases when the rotation speed of the compressor stops increasing, and the flow rate of the first heat medium flowing into the heat exchanger decreases when the rotation speed of the compressor stops decreasing. A heat supply facility that supplies heat;
a plurality of air conditioning and hot water supply facilities that receive heat from the heat supply facility;
The heat supply facility includes:
A first circulation circuit for circulating a first heat medium,
The air conditioning and hot water supply equipment includes:
a second circulation circuit for circulating a second heat medium;
a branch line connected to the first circulation circuit;
a heat pump that transfers heat from the branch pipe to the second circulation circuit;
a pressure adjustment mechanism that is provided in the branch pipe and adjusts a pressure of the first heat medium flowing through the branch pipe to a predetermined pressure,
The air conditioning and hot water supply equipment includes:
a flow rate adjustment mechanism provided in the branch pipe downstream of the pressure adjustment mechanism, the flow rate adjustment mechanism adjusting a flow rate of the first heat medium flowing through the branch pipe;
A control device for controlling the flow rate adjustment mechanism,
The heat pump comprises:
a third circulation circuit in which a third heat medium circulates;
a heat exchanger for exchanging heat between the branch pipe and the third circulation circuit;
a compressor provided in the third circulation circuit and configured to compress the third heat medium,
An air conditioning and hot water supply system, wherein a flow rate of the first heat medium flowing into the heat exchanger increases when the rotation speed of the compressor stops increasing, and a flow rate of the first heat medium flowing into the heat exchanger decreases when the rotation speed of the compressor stops decreasing. The air conditioning and hot water supply system according to claim 4 , wherein the control device controls the flow rate adjustment mechanism based on a rotation speed of the compressor. The control device includes:
When the rotation speed of the compressor reaches an upper limit rotation speed, a target opening degree of the branch pipe is increased;
The air conditioning and hot water supply system according to claim 6 , wherein the target opening degree of the branch pipe is reduced when the rotation speed of the compressor reaches a lower limit rotation speed. The air-conditioning and hot water supply system according to claim 1 , wherein the air-conditioning and hot water supply facility includes a transformer connected to a power source and supplying power to the flow rate adjustment mechanism. The air conditioning and hot water supply equipment includes:
a pressure opening adjustment unit including the pressure adjustment mechanism and the flow rate adjustment mechanism;
The air conditioning and hot water supply system according to claim 1 , further comprising: an air conditioning and hot water supply unit including the heat pump and the second circulation circuit. a second heat supply facility that supplies heat;
a plurality of air conditioning and hot water supply systems that receive heat from the second heat supply facility;
A collective air conditioning and hot water supply system, wherein at least one of the plurality of air conditioning and hot water supply systems comprises the air conditioning and hot water supply system according to any one of claims 1 to 9 . The collective air conditioning and hot water supply system according to claim 10 , wherein the plurality of air conditioning and hot water supply systems are installed side by side in a vertical direction.

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