JPH01281379A - Heat pump system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a heat pump system,
In particular, the present invention relates to a heat pump system having a multi-room heating function and a bathtub heating function.

(Prior art) As a conventional example of the heat pump system as described above,
For example, the apparatus described in Japanese Patent Application Laid-Open No. 62-288454 can be mentioned. In this system, a single outdoor unit has a compressor and an outdoor heat exchanger, and a plurality of indoor units each having an indoor heat exchanger, and a bath heat source that is used for heating bath water, especially for reheating. Bath units having exchangers are connected in parallel to each other, and the refrigerant discharged from the compressor is circulated from the indoor heat exchanger or the bath heat exchanger to the outdoor heat exchanger, thereby heating or If the bath heating operation is to be performed, and if a heating operation request from the indoor unit and a bath heating operation request from the bath unit are generated at the same time, the bath heating operation will be performed under the conditions described below. This is given priority.

The reason why we have set these conditions to limit simultaneous operation is because it is assumed that the frequency of simultaneous operation of heating all rooms and bath heating, which is the maximum load condition, is required to be extremely rare, so we have set the conditions to limit simultaneous operation. If the capacity of the compressor is selected based on the above, the equipment will become larger and the cost will increase.Also, the reason why priority is given to the bath heating operation is that This was done considering that the heating operation time is relatively short and that a drop in hot water temperature causes greater discomfort to the user than a drop in room temperature.

In the above device, when a heating operation request and a bath heating operation request are generated at the same time, the simultaneous operations are started, and then the temperature of the condensed liquid refrigerant at the outlet side of the bath heat exchanger is If it is determined that the difference between the bath temperature and the bath temperature is smaller than the standard value, that is, the bath heating capacity is small,
Heating operation is stopped and the system automatically switches to bath heating operation alone.

(Problem to be solved by the invention) However, in the above case, when it is determined that the bath heating capacity is small, the heating operation is stopped in all rooms on the indoor side that had been operated up to that point, so Even though the bath heating capacity has become excessive or the compression capacity of the compressor has been controlled to decrease, the compressor has surplus capacity, but the compressor remains in operation until the bath heating operation ends. There is a problem in that the vehicle continues to be operated at low speeds, resulting in a decrease in utilization efficiency and, therefore, inability to provide fully satisfactory comfort.

This invention has been made in view of the above, and its purpose is to create a heat pump system that maintains bath heating capacity above a predetermined value and enables simultaneous heating operation in as many rooms as possible, thereby improving comfort compared to conventional systems. Our goal is to provide the following.

(Means for Solving the Problem) Therefore, the heat pump system of the present invention includes a plurality of indoor units A to C, each of which has an indoor heat exchanger 19 in an outdoor unit x having a compressor 1 and an outdoor heat exchanger IO.
and a reheating unit Y including a bath heat exchanger 30 for heating bath water are connected in parallel to each other,
An operation control means 51 is provided for controlling the heating operation in response to the heating operation request signal from each of the indoor units A to C, and the bath heating operation in response to the bath heating operation request signal from the reheating unit Y, respectively. As shown in Figure 1, the heat pump system further includes a priority determining means 59 for determining the priority of each of the indoor units A...C, and a bath heating ability detecting means for detecting the bath heating ability. 60, and when the detection value of the bath heating capacity detection means 6o is below the reference value when the heating and bath heating are being operated simultaneously, each indoor unit (A) that is in operation is prioritized. A bath heating capacity monitoring means 55 is provided which stops the heating according to the timing.

(Function) In the heat pump system described above, when the detection value of the bath heating capacity detection means 60 becomes equal to or less than the reference value during simultaneous operation of heating and bath heating, each indoor unit A in operation is ... is controlled to maintain the bath heating capacity at a predetermined capacity by sequentially stopping the compressor 1 in priority order, so the capacity of the compressor 1 is maximized without compromising the comfort of bath users. Simultaneous heating operation will be maintained across the multiple rooms utilized.

As a result, the number of rooms in which heating operation is forcibly stopped becomes smaller than in the past, making it possible to improve comfort.

(Example) Next, a specific example of the heat pump system of the present invention will be described in detail with reference to the drawings.

First, FIG. 2 shows a refrigerant circuit diagram of a heat pump system configured to apply the present invention.

In the figure, X is an outdoor unit, and three indoor units A to C, a reheating unit Y, and a hot water supply unit Z are connected to the outdoor unit X.

The above-mentioned outdoor unit 8
and a second gas pipe 9 are connected. Note that the above compressor 1
has an inverter 5 for controlling its rotation speed, that is, its compression capacity, and a first electromagnetic valve 6 is provided in the discharge pipe 2, and an accumulator 7 is provided in the suction pipe 3. . The first gas pipe 8 is connected to an outdoor heat exchanger 10, and the second gas pipe 9 is connected to a header 11, with a gas shutoff valve 12 interposed therebetween. J: An outdoor fan 17 is attached to the outdoor heat exchanger 10, and a liquid pipe 13 is also connected to the liquid pipe 13. A container 15 and a liquid shutoff valve 16 are provided in this order.

Between the tip of this liquid pipe 13 and the header 11, there are a plurality of branch refrigerant pipes 18...18 each having a second electric expansion valve 20...20 interposed therein. They are connected in parallel to each other, and three of them are connected to the indoor heat exchangers 19 of each indoor unit A to C (indoor unit A
(Only shown in the figure) are provided respectively. Note that each indoor unit 1-A-C is composed of the indoor heat exchanger 19 and the indoor fan 21, respectively. On the other hand, the bath heat exchanger 30 of the reheating unit Y is interposed in the remaining one of the branch refrigerant pipes 18. The configuration of this reheating unit Y will be explained later.

Furthermore, the discharge pipe 2 of the compressor 1 is provided with a hot water supply gas pipe 2.
A hot water supply liquid pipe 24 is connected to the liquid receiver 15 interposed in the liquid pipe 13, and a hot water supply unit is connected between the hot water supply gas pipe 22 and the hot water supply liquid pipe 24. Z
A hot water supply heat exchanger 23 is connected. A second magnetic valve 25 is provided in the gas pipe 22 for hot water supply, and a capillary tube 26 and a check valve 27 are provided in the liquid pipe 24 for hot water supply.

The hot water supply heat exchanger 23 is disposed on the bottom side of a hot water storage tank 31 that is constituted by a cylindrical closed tank. Hot water supply pipe 3 is connected to the hot water supply port on the upper end side of this hot water storage tank 31.
2, and a water supply pipe 33 is connected to the water supply port on the bottom side, respectively, and a ring (not shown) at the tip of the hot water supply pipe 32 is connected.
When the valve is opened, the pressure of the tap water acting through the water supply pipe 33 pushes up the hot water in the upper part of the hot water storage tank 31 to the hot water supply pipe 32, and at the same time, the same amount of hot water as the amount of hot water supplied is supplied to the hot water supply pipe 32. Water is replenished from the water supply pipe 33 to the bottom side of the hot water storage tank 31. - A hot water temperature sensor 34 constituted by, for example, a thermistor is attached to a position on the bottom side of the outer peripheral wall of the hot water storage tank 31. Based on the hot water temperature detected by the hot water temperature sensor 34, the hot water storage tank 3 is heated by the condensation heat of the condensed refrigerant in the hot water supply heat exchanger
It is designed to heat the hot water inside 1.

On the other hand, the above-mentioned reheating unit Y is the above-mentioned heat exchanger for baths! 4
It connects the A vessel 30 and a water outgoing pipe 36 and a water returning pipe 37 that connect the bath heat exchanger 30 to the bathtub 35. A circulation pump 38 is interposed in the water outgoing pipe 36, and by operating the circulation pump 38, the hot water in the bathtub 35 flows in the path direction from the water outgoing pipe 36 to the water returning pipe 37. The water is then circulated through the bath heat exchanger 30. At this time, the heat of condensation of the condensed refrigerant in the bath heat exchanger 30 is applied to raise the temperature of the bath water. Although it is also possible to heat the bathtub water from the supplied water temperature state by the above-mentioned reheating unit Y,
Normally, the heating operation by the reheating unit Y is performed in response to a temperature drop after the hot water stored in the hot water storage tank 31 is supplied to the bathtub 35. In addition, the above water outbound pipe 3
6 is a bathtub water temperature first sensor 39 for detecting the bathtub water temperature, and the water return pipe 37 is for the hot water returned to the bathtub 35 after being heated by the bath heat exchanger 30. A second bathtub water temperature sensor 40 is attached to each bathtub to detect the temperature of the bathtub.

In the heat pump system having the above configuration, refrigerant circulation control during heating and air conditioning operation will be explained next. In this operation, the first solenoid valve 6 is opened, the second solenoid valve 25 is closed, and the compressor 1
The refrigerant is passed through the four-way switching valve 4 and the second gas pipe 9, condensed in each indoor heat exchanger 19...19, and then passed through the liquid pipe I3 to evaporate in the outdoor heat exchanger lO. let

Thereafter, the gas is returned to the compressor 1 from the first gas pipe 8 and the four-way switching valve 4. In this case, the degree of superheating of the evaporative refrigerant is controlled by the first electric expansion valve 14, and each of the 21st dynamic expansion valves 20 controls the amount of refrigerant distributed to each indoor heat exchanger 19. By causing the bath heat exchanger 30 to function as a condenser in the same refrigerant circulation direction as the heating operation described above, bath heating operation alone or heating and bath heating operations can be performed simultaneously. In addition, heating operation with bath heating stopped or heating operation with some rooms stopped is performed on the reheating unit Y side, indoor unit A in the stopped room.
This is done by setting each of the second electric expansion valves 20 on the side to a stop opening degree (an opening degree that allows a small amount of refrigerant to flow in proportion to natural heat radiation in order to prevent liquid from returning to the compressor l).

On the other hand, cooling operation is performed by switching the four-way switching valve 4 from the above to circulate the refrigerant from the compressor 1 from the outdoor heat exchanger 10 to each indoor heat exchanger 10. The expansion valve 14 is fully opened, and the second electric expansion valves 20 on the reheating unit Y side and on the indoor unit A side in the cooling-off room, which control the degree of superheating of the refrigerant in each second electric expansion valve 20, are fully opened. Close it.

Note that during hot water heating operation, the first solenoid valve 6 is closed, and the second solenoid valve 25 is closed.
Open the compressor and operate the compressor. Then, the refrigerant passes through the hot water supply gas pipe 22 and condenses in the hot water supply heat exchanger 23, then passes through the hot water supply liquid pipe 24 and the liquid pipe 13, and evaporates in the outdoor heat exchanger 10, and then, The flow is returned to the compressor 1 via the first gas pipe 8 and the four-way switching valve 4. In this case, each second electric expansion valve 20 is fully closed, and the first electric expansion valve 14 controls the degree of superheating of the evaporative refrigerant. In addition, for simultaneous operation of heating and hot water heating, both the first and second solenoid valves 6.25 are opened, the refrigerant is condensed in both the indoor heat exchanger 19 and the hot water heat exchanger 23, and the outdoor heat exchanger is condensed. This can be done by circulating a refrigerant that is evaporated in the vessel 10. Further, in the above, simultaneous operation of cooling and hot water heating can be performed by closing the first TL valve 6, opening the second electromagnetic valve 25, and fully opening the first electric expansion valve 14. At this time, the refrigerant from the compressor 1 passes through the hot water supply gas pipe 22 and condenses in the hot water supply heat exchanger 23, and then passes through the hot water supply liquid pipe 24 and the liquid receiver 15.
, through the liquid pipes 13 to each indoor heat exchanger 19, where it is evaporated, and then returned to the compressor l through the second gas pipe 9 and the four-way switching valve 4.

In this case, each second electric expansion valve 20 controls the degree of superheating of the evaporative refrigerant. In addition, by making the above-mentioned refrigerant i-ring path circulate from the hot water supply heat exchanger 23 to the bath heat exchanger 30, the exhaust heat of the bathtub hot water after bathing is recovered to the hot water storage tank 31. It is also possible.

Next, regarding the operation control of the heat pump system mentioned above,
For convenience, the operation mode control between heating operation and bath heating will be described as an example with reference to the operation control system diagram shown in FIG. 3.

First, each indoor unit A to C has an indoor control device 4.
1 (illustration is made only for indoor unit A, the same applies hereinafter), but these indoor control devices 41 include:
A remote control switch 42 and a room temperature detection sensor 43 are connected to each other. The remote control switch 42 has an operation switch and a room temperature setting switch for setting the desired room temperature, and when the operation switch is ON,
And when the room temperature detected by the room temperature detection sensor 43 is lower than the set room temperature, the indoor control device 41
A heating operation request signal is transmitted, and at the same time, a temperature difference signal between the set room temperature and the detected room temperature is also transmitted. on the other hand,
As will be described later, the heating operation command signal issued by the outdoor unit X is input to each indoor control device W41, so that the indoor fan 21 is
is activated, and heating operation for that room is performed.

Next, the reheating unit Y includes a bath control device 45, and this bath control device 45 includes the above-mentioned bathtub water temperature first sensor 39 and bathtub water temperature second sensor 40, and a sensor for reheating operation. A remote control 46 is connected. The reheating operation remote control 46 is provided with a hot water temperature setting switch and a reheating operation switch, and the reheating operation switch is turned on.
and when the hot water temperature detected by the first bath water temperature sensor 39 is lower than the set hot water temperature, a bath heating operation request signal is transmitted from the bath control device 45 to the outdoor unit X,
At the same time, a temperature difference signal obtained by subtracting the temperature detected by the first bathtub water temperature sensor 39 from the temperature detected by the second bathtub water temperature sensor 40 is transmitted as the bath heating ability signal ΔT. On the other hand, a bath heating operation command signal issued by the outdoor unit
is activated, and a bath heating operation in which bath water is circulated through the bath heat exchanger 30 is performed.

On the other hand, the outdoor unit X includes an outdoor control device (operation control means) 51, an inverter control device 52, and a valve switching control device 53. The heating operation control in the case where the heating operation request signal is not output and there is a heating operation request signal from the indoor side will be explained.

The outdoor control device 51 includes an operation request unit grasping section 54 and an operation unit determining section (bath heating capacity monitoring means) 5.
5 and a frequency control section 56 are provided. The operation request unit grasping section 54 has a function of determining the indoor unit with the operation request from the heating operation request signal, and the operation unit determining section 55 has the function of determining the indoor unit with the operation request from the above-mentioned heating operation request signal. The operation unit signal is outputted to the frequency control section 56 and the valve switching control device 53, and a heating operation command signal is outputted to each indoor unit having the operation request. As a result, first, the valve switching control device 53 controls the first and 21st M1 valves 6, 25, the four-way switching valve 4, the first and The operation of the second electric expansion valve 14.20 is controlled. In addition, for each indoor unit that requires operation, each indoor fan 2
1 is started. On the other hand, the frequency control section 56 first reads out the load level of each unit for which an operation is requested from the load level storage section 57 based on the operation unit signal and sums them up. This load level storage section 57 contains a numerical value corresponding to the rated capacity of each unit (for example, +1111.280 for a unit with a rated capacity of 2240 kcal/h).
At 0kcal/h, "1.5"-.) is stored in advance. Furthermore, the frequency control section 56 extracts the maximum temperature difference among the temperature difference signals from each indoor unit with an operation request, and then extracts the maximum temperature difference from among the temperature difference signals from each indoor unit that is requested to operate, and then selects an initial frequency preset for various combinations of load levels and temperature differences. An initial frequency corresponding to the combination of the total load level and maximum temperature difference is selected from the data table, and is output to the inverter control device 52. As a result, the inverter control device 52 starts driving the compressor l at the initial frequency, and after the rotation speed has reached the initial frequency, the inverter control device 52 starts driving the compressor l at the initial frequency, and then responds to the subsequent change in the maximum value of the temperature difference signal. For example, the frequency control section 56 sequentially generates a frequency corresponding to a change in load by PID control, and the heating operation is continued while controlling the compression capacity of the compressor 1 at this frequency. .

Note that if the number of operating rooms on the indoor side increases or decreases, the above-mentioned procedure is newly repeated starting from the control for selecting the initial frequency.

Next, an explanation will be given of operation control when a bath heating operation request signal is output during the heating operation of any of the indoor units A to C, or when a heating operation request signal is output during the bath heating operation. The bath heating operation request signal is input to the operation unit determining section 55. The operation unit determining section 55 sends the reheating unit signal to the frequency control section 56 and the valve switching control device 5 together with the operation unit signal corresponding to the indoor unit with the operation request described above.
3 and also outputs a heating operation command signal to the indoor unit with the operation request, and outputs a bath heating operation command signal to the reheating unit I-Y. As a result, the valve switching control device 53 first provides a refrigerant circulation path during simultaneous operation of indoor unit heating and bath heating for which the operation request is made (the operation of the above response is controlled. The indoor fan 21 and circulation pump 38 are operated in a certain indoor unit and a reheating unit +-y, respectively.

On the other hand, the frequency control section 56 calculates the total load level of the indoor unit with the operation request and the reheating unit Y in the same way as above, selects the maximum frequency in the frequency variable range corresponding to this total load level, and selects the maximum frequency in the frequency variable range corresponding to this total load level. The frequency is output to the control device 52, and heating and bath heating are simultaneously operated at this frequency.

After starting the simultaneous heating and bath heating operations as described above, the operation unit determining section 55 further performs control to maintain the bath heating capacity at a predetermined value or higher. For this purpose, the outdoor unit X is provided with a priority setting switch 58, and the setting contents of this switch 58 are inputted to the operation unit determining section 55 via a priority determining section (priority determining means) 59. Furthermore, this operation unit determination section 55 has the above-mentioned reheating unit Y.
The bath heating capacity signal ΔT is input from the bath heating capacity signal ΔT.

After a predetermined period of time (for example, 0.5 to 1 minute) has elapsed after the simultaneous operation of heating and bath heating is started, the operation unit determining section 55 performs a process according to the flowchart shown in FIG. 4. That is, first, the bath heating capacity signal ΔT
is read (step S1), and then this ΔT is compared with a preset reference value (for example, 6° C.) (step S2).

If the above-mentioned ΔT is equal to or greater than the reference value, it is assumed that a simultaneous operation is being performed in which the predetermined bath heating capacity is satisfied, and the current operating state is continued (step S3). on the other hand,
If the above-mentioned ΔT is smaller than the above-mentioned reference value, the process moves from step S3 to step S4, and among the indoor units grasped by the operation request unit grasping section 54, that is, the According to the priority order determined by the priority order determination unit 59, the heating operation command signal to the indoor unit having a lower priority order is stopped.

It also outputs a signal to that effect to the valve switching control device 53 to stop the heating operation of the indoor unit with the lower priority. In this way, the heating capacity of the reheating unit Y is increased. Then, after a certain period of time has elapsed, the bath heating capacity signal ΔT is read again (step S5).
Then, this ΔT is compared with the reference value (for example, 6°C) (step S6), and if the reference value is still not reached, the indoor unit with the lower priority at this time is stopped again (step S7). ), and thereafter, by repeating the processes from step S5 to step S7 at regular time intervals, the heating operation of the indoor units with lower bond priority is sequentially stopped and the bath heating capacity is increased to a predetermined value. conduct. If it is determined in step S6 that ΔT has exceeded the reference value, then in step S8 the operation of the indoor unit with the higher priority order among the indoor units with heating operation request signals that have been stopped is resumed. As a result, from then on, the bath heating capacity is substantially maintained at a predetermined value, and the simultaneous operation state in which the capacity of the compressor 1 is utilized to the maximum is continued. Note that the above-mentioned bath heating operation is completed in a relatively short time, and when the bath water temperature reaches the set water temperature by continuing the above-mentioned simultaneous operation, the bath heating operation request signal is no longer generated. At this time, the heating operation is restarted in all the rooms that have generated the heating operation request signal.

Although one embodiment of the present invention has been described above,
The above embodiment is not intended to limit the present invention, and various changes can be made within the scope of the present invention. Although an example is shown in which the bath heating capacity detection means 60 is configured in steps S1 and 82 and steps S5 and S6 in FIG. It is possible to adopt a configuration that determines the bath heating ability.

(Effects of the Invention) As described above, in the heat pump system of the present invention, in order to maintain the bath heating capacity above a predetermined value, the indoor units that are in simultaneous heating operation are sequentially stopped in accordance with the priority order. As a result, simultaneous heating operation is carried out to the extent that the compressor capacity is utilized as much as possible without compromising the comfort of bath users.As a result, heating operation is forced to stop in a number of rooms. As a result, comfort can be improved.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram of the present invention, FIG. 2 is a refrigerant circuit diagram of a heat pump system according to an embodiment of the present invention, FIG. 3 is an operation control system diagram of the heat pump system, and FIG. 4 is a diagram of the operation control system of the heat pump system. It is a flowchart figure of bath heating capacity monitoring control performed by an operation unit determination part. 1...Compressor, 10...Outdoor heat exchanger, 19...
Indoor heat exchanger, 30... Bath heat exchanger, 51...
Outdoor control device (operation control means), 55... Operation unit determining section (bath heating ability monitoring means), 59... Priority determining section (priority determining means), 60... Bath heating ability detecting means, A, B, C...indoor unit, X...
Outdoor unit, Y... Reheating unit. Figure 1 Figure 4

Claims (1)

[Claims] 1. An outdoor unit (X) having a compressor (1) and an outdoor heat exchanger (10), a plurality of indoor units (A) to (C) each having an indoor heat exchanger (19), and a bathtub A reheating unit (Y) having a bath heat exchanger (30) for heating is connected in parallel with each other, and a heating system that responds to heating operation request signals from each of the indoor units (A) to (C). and a bath heating operation in response to a bath heating operation request signal from the additional heating unit (Y), the heat pump system comprising an operation control means (51) for controlling each of the indoor units. A priority determining means (59) for determining the priority of (A)...(C), a bath heating ability detecting means (60) for detecting the bath heating ability, and simultaneous operation of the heating and bath heating. Bath heating capacity monitoring means (60) that stops each indoor unit (A) in operation according to priority when the detected value by the bath heating capacity detection means (60) becomes below a reference value during 55) A heat pump system characterized by comprising: