JPH0633914B2 - Heat pump system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a heat pump system, and more particularly to a heat pump system having a function of heating bath water by a heat exchanger for bath.

(Prior Art) As a conventional example of a heat pump system capable of heating bath water by using a bath heat exchanger, for example, Japanese Patent Laid-Open No.
An example is the device described in Japanese Patent Publication No. 169045. This device will be described with reference to FIG.
In the figure, (51) is a compressor, (52) is an indoor heat exchanger,
(53) is an outdoor heat exchanger, (54) is a hot water storage tank unit, (5
5) shows bathtub units, respectively, and the above-mentioned components (51) to (55) are connected by a refrigerant circuit (56). The bathtub unit (55) includes a bathtub (57),
It is composed of a bath heat exchanger (58) and a pump (59) for circulating bath water between the two (57) and (58). The refrigerant circuit (56) includes the first to fourth parts.
Electric expansion valves (61) to (64), first and second four-way switching valves (65), (66), first and second electromagnetic valves (67), (68) are interposed, and these The refrigerant circulation circuit can be switched by controlling the valves (61) to (68). That is, the third and fourth electric expansion valves (63), (64)
The compressor 1 by opening the second solenoid valve (68)
Refrigerant is circulated from the indoor heat exchanger (52) to the outdoor heat exchanger (53) through the second four-way switching valve (66) to heat the room, while the first and second indoor heat exchangers are heated. By opening the three electric expansion valves (61) and (63) and the first solenoid valve (67), the refrigerant discharged from the compressor 1 is transferred to the first four-way switching valve (6).
The bath heat can be heated by circulating it from the bath heat exchanger (58) to the outdoor heat exchanger (53) via 5).

Further, although not shown, the device has a room temperature thermometer for further detecting the room temperature and a hot water temperature thermometer for detecting the temperature of the bath water, and when the room temperature becomes lower than the set temperature. Each of the above valves (61) to (64), so that the heating operation is performed by the signal from the room temperature thermostat and the bath heating operation is performed by the signal from the hot water thermostat when the bath water falls below the set temperature. The operation of (67) and (68) is controlled. In the above apparatus, when there is an operation request signal from both the room temperature thermostat and the hot water thermostat, the heating operation is not performed but the bath heating operation is preferentially controlled. The reason why the switching operation is performed in this way is that if the capacity of the compressor 1 is selected on the assumption that both of the above operations are performed at the same time, the size of the device itself increases and the cost increases. The reason why the bath heating operation is prioritized is that it takes into consideration that the user feels more uncomfortable when the temperature of the water is lowered than when the temperature of the room is lowered.

[Problems to be solved by the invention]

By the way, in recent years, an inverter heat pump system having a structure in which a plurality of indoor units are connected in parallel to one outdoor unit equipped with a compressor having a variable compression capacity and a bath unit is further connected in parallel to the indoor unit has been put into practical use. However, it is extremely unreasonable to directly adopt the operation control method for performing independent bath heating operation in such a heat pump system as described above by always giving priority to bath heating. . That is, in the inverter heat pump system as described above, the capacity of the compressor has an excess depending on the load condition on the heating side and the like, and the bath heating operation can be performed by this excess capacity, that is, heating and bath heating. In some cases, it may not be possible to simultaneously perform heating operation, and in such a case it is not necessary to uniquely perform heating operation in order to make heating users uncomfortable without utilizing the surplus capacity. This is because

The present invention has been made to solve the above-mentioned conventional drawbacks, and an object thereof is to enable simultaneous operation of bath heating and heating depending on the situation, and to reduce user discomfort. It is to provide a heat pump system capable of

(Means for Solving Problems) Therefore, in the heat pump system of the present invention, the outdoor unit (X) having the compressor 1 having a variable compression capacity and the outdoor heat exchanger (10), and the indoor heat exchanger (19). Bath unit (D) having a heat exchanger for bath (22) connected in parallel to the indoor heat exchanger (19) while forming a refrigerant circulation circuit with the indoor unit (A) having In a heat pump system equipped with, as shown in FIG. 1, a room and a bathtub unit (A) having an operation request,
(D) load capacity value grasping means (44) for grasping the total load capacity value, compression capacity storing means (47) for storing the maximum compression capacity of the compressor 1 corresponding to the load capacity value,
A heating operation command signal generating means (37) that detects a heating load and issues a heating operation command signal when the heating load is larger than a reference value, and a bath when the bath temperature is detected and the bath temperature is less than the reference value. The bath heating operation command signal generating means (40) for issuing a heating operation command signal, the bath heating capacity detecting means (28) for detecting a bath heating capacity, and the compressor 1 when both of the above operation command signals are issued The compressor operation control means (32) that operates at the maximum compression capacity in the total load capacity value and the simultaneous heating operation and bath heating operation when the detected bath heating capacity during the operation is equal to or greater than the reference value. An operation control means (33) for controlling the refrigerant circulation system is provided so as to perform the operation and the bath heating independent operation when the bath heating capacity is less than the reference value.

(Operation) When both the heating and bath heating operation command signals are output as described above, the compressor 1 is operated at the maximum capacity in the grasped total load capacity value, and the bath heating capacity is changed during this operation. When the bath heating capacity is detected and the bath heating capacity is higher than the reference value, heating and bath heating are performed at the same time, so the heating operation frequency is higher than in the past, which causes user discomfort. It can be reduced.

(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. As shown in the figure, this device has an outdoor unit (X), three indoor units (A) to (C), and a bath unit (D). It is a thing. The outdoor unit (X) has the compressor 1,
The discharge pipe (2) and the suction pipe (3) of the compressor 1 are each connected to a four-way switching valve (4). The compressor 1 has an inverter (5) for controlling its rotational speed, that is, its compression capacity, and an intake pipe (3) is provided with an accumulator (6). The four-way switching valve (4) has a first gas pipe (7).
And a second gas pipe (8) are connected, the first gas pipe (7) is connected to an outdoor heat exchanger (9), and the second gas pipe (8) is a header (10). It is connected to the.
A first liquid pipe (11) is connected to the outdoor heat exchanger (9), and the first liquid pipe (11) is connected to the liquid receiver (12), and in the middle of the process. A first electric expansion valve (13) is provided. The liquid receiver (12) has a second liquid pipe (1
One end of 4) is connected, but this second liquid pipe (14)
Four branch refrigerant pipes (15) to (18) are connected between the other end of the header and the header (10) in the figure. Three pipes (15), (1
6) and (17) are the indoor unit (A) and
(B) and (C), and the remaining refrigerant pipe (18) is connected to the bath unit (D). Although the above indoor units (A) to (C) are shown only for one indoor unit (A), the indoor heat exchanger (19) and the indoor fan (2)
0) and. The bathtub unit (D) includes a bathtub (21), a bath heat exchanger (22), and a pump (23) for circulating bathtub hot water between the two (21) and (22). I have. In addition, in each of the refrigerant branch pipes (15) to (18), the liquid pipe (14)
The second electric expansion valves (24) to (27) are provided at the side positions, respectively. In the branch refrigerant pipe (18) on the bath unit (D) side, a temperature sensor (28) is attached between the unit (D) and the second electric expansion valve (27). The temperature sensor (28) is for detecting the temperature of the condensed refrigerant at the outlet of the bath heat exchanger (22).

In the heat pump system described above, when performing the heating operation, the second electric expansion valve (27) on the side of the bath unit (D) is stopped to the opening degree (to prevent the liquid from returning to the compressor 1, so that the natural heat is radiated). The degree of opening that allows a slight amount of refrigerant to flow, which is the same below), and other necessary second electric expansion valves (24) to (26) are connected to the indoor heat exchanger (19) ..
The control opening for controlling the degree of supercooling in (19) is used, and the refrigerant discharged from the compressor 1 is passed through the four-way switching valve (4) to each indoor heat exchanger (19). ) To the outdoor heat exchanger (9). In this case, the first electric expansion valve (13) has a control opening so as to control the heating degree of the outdoor heat exchanger (9). When the bath heating operation is performed, the second electric expansion valves (24) to (26) on the indoor units (A) to (C) side are set to stop openings, and the second electric expansion valves on the bath unit (D) side are opened. The electric expansion valve (27) and the first electric expansion valve (13) are set to the same control opening as above, and the refrigerant discharged from the compressor 1 is exchanged with the outdoor heat from the bath heat exchanger (22) in the same manner as above. Circulate to vessel (9). Bath heating
Required second electric expansion valve (24) for simultaneous heating operation
(26) and the second electric expansion valve (27) may be set to the control opening. Further, in the cooling operation and the bath cooling operation, the four-way switching valve (4) is switched so that the refrigerant discharged from the compressor (1) is reversed from the above, from the outdoor heat exchanger (9) to the indoor heat exchanger (19).・
・ It is done by circulating it to (19) and the heat exchanger for bath (22). In this case, the first electric expansion valve (1
3) is fully opened, and the degree of superheat of the evaporated refrigerant is controlled by the second electric expansion valves (24), (27).

Next, the operation control circuit of the heat pump system will be described with reference to FIG. 3, but the following description will be made regarding the heating operation and the bath heating operation. As shown in the figure, the outdoor unit (X) has an outdoor control device (31),
The outdoor control device (31) further includes a frequency control circuit (32) as compressor operation control means and an operation control circuit (33) as operation control means. The inverter (5) is connected to the frequency control circuit (32), and the frequency control circuit (32) controls the frequency of the inverter (5), that is, the compression capacity of the compressor 1. ing. Further, the operation control circuit (33) is connected to the temperature sensor (28) and a valve control circuit (34). The valve control circuit (34) is connected to the operation control circuit (33). The second electric expansion valve (2
4) to (27) and the four-way switching valve (4) are controlled to perform heating operation,
It has a function of controlling operation modes such as bath heating operation and heating / bath heating simultaneous operation.

On the other hand, the indoor units (A) to (C) are the indoor control devices (3
5) It has an indoor unit (A) (only one indoor unit (A) is shown, but the same applies below).
The heating operation switch (36) and the room temperature thermostat (37) are connected to 5), respectively. And each indoor control device (3
From 5), the following four signals are output to the outdoor control device (31). That is, it is the heating operation request signal generated by the ON operation of the heating operation switch (36), and the heating operation output from the room temperature thermostat (37) when the heating operation request signal is output and the room temperature becomes lower than the set temperature. Command signal The ΔT signal corresponding to the difference between the room temperature and the set temperature detected by the indoor thermostat (37) and the model code signal. For example, in the heating operation, in the indoor control device (35), as shown in FIG. 4, assuming that the operation switch is ON (step S1), ΔT =
Calculated temperature-set temperature (step S2), ΔT ≤ 0
Is confirmed (step S3), this is changed to the ΔT signal in step S4, and this ΔT signal and model code signal are transmitted to the outdoor control device (31).

Further, as shown in FIG. 3, the bathtub unit (D) has a bath control device (38), and this bath control device (38) has a bath operation switch ( 39)
And a hot water temperature thermostat (40) for detecting the hot water temperature of the bathtub (21) are connected. The bath control device (38) outputs the following four signals to the outdoor control device (31) in the same manner as the indoor control device (35).

Bath heating operation request signal by turning on the bath heating switch (39) Bath heating operation command signal from the bath temperature thermostat (40) ΔT signal corresponding to the difference between the detected bath temperature and the set temperature Model code signal And each of the above signals , And is transmitted to the outdoor control device (31) in a procedure substantially similar to that shown in FIG.

On the other hand, in the outdoor control device (31), the ΔT value detection circuit (41) obtains the ΔT value based on the above ΔT signal as in the following (1) to (7).

(1) 0 ≦ ΔT signal ··· ΔT value = 0 (2) -0.5 ≦ ΔT signal <0 ···· ΔT value = −0.5 (3) -1.0 ≦ ΔT signal <−0.5 ·· ΔT Value = -1.0 (4) -1.5 ≤ ΔT signal <-1.0 ... ΔT value = -1.5 (5) -2.0 ≤ ΔT signal <-1.5 ... ΔT value = -2.0 (6) -2.5 ≤ ΔT signal <- 2.0 ·· ΔT value = −2.5 (7) ΔT signal <−2.5 ··· ΔT value = −3.0 Then, in the outdoor controller (31), the total temperature difference detection circuit (42) is used in each room and bath unit (A). ) ~ (D)
And the maximum temperature difference detection circuit (43) as the heating load detection means finds the maximum of the absolute values of the above ΔT values.

Further, in the outdoor control device (31), the load capacity value grasping means (44) operates based on the model code signals output from the indoor control devices (35) and (35) and the bath control device (33). The total load capacity value ΣS of all the indoor units and the bathtub units (A) to (D) that have been requested (including those with the thermostat stopped) is grasped, which is performed by the following procedure. ing. First, the model code signals output from the indoor control devices (35) and (35) and the bath control device (38) correspond to the capacities of the indoor heat exchanger (19) and the bath heat exchanger (22). For example, for a capacity of 2240 kcal / h, a code of "000", a value of "001" for 2800 kcal / h, and a value of "01" for 3550 kcal / h.
"0" is also defined as "011" at 4500 kcal / h, and these codes are for each unit (A) ~
It is stored for each (D). Further, in the outdoor control device (31), the storage unit (45) stores the load capacity value S corresponding to the model code. This load capacity value S
Has a capacity of 2240kcal / h (model code "000") as the standard value "1" and 2800kcal / h (model code "001") as "1.2".
5550, 3550kcal / h (model code "010") to "1.5"
4500kcal / h (model code “011”) is set to “2”, and the load capacity value grasping circuit (46) has units (A) to
For each (D), the load capacitance value S is read out and the sum ΣS of these is calculated.

In the outdoor control device (31), the maximum absolute values of the total load capacity values ΣS, ΣΔT values, and ΔT values of the indoor and bathtub units (A) to (D) for which operation is requested as described above are grasped, respectively. However, based on these, the frequency control circuit (32) as the compressor control means controls the compressor 1
The frequency of is controlled. First, the initial setting frequency of the inverter (5) is set. The initial setting frequency is set as shown in Table 1 in relation to the total load capacity value ΣS grasped above and the ΔT value which is the maximum absolute value. It is what is done. Each initial setting frequency shown in Table 1 is stored in the storage section (47) as a compression capacity storage means.

The upper limit of ΣΔT used in Table 1 is 3.0,
In other words, 3.0 and above are all set to 3.0, the reason for which will be described later.

First, the frequency control when the heating operation is performed in each of the indoor units (A) to (C) without the bathtub unit (D) being operated will be described with reference to FIG. 5. First, in step S10. , It is determined whether the compressor (1) is stopped, and if it is stopped, the total load capacity value ΣS obtained by moving to step S1 and ΔT having the maximum absolute value are obtained.
The default frequency is selected according to Table 1 in relation to the value and the inverter (5) is operated at this frequency. Then, after that, and when the compressor (1) is operating in step S10, the frequency control is performed after the next step S12. , P control) and integral control (hereinafter referred to as I control). First, in step S12, it is determined whether or not a predetermined time (for example, 30 seconds) has elapsed after the activation or the previous control. In the case of NO, the process returns to step S10 to maintain this frequency, but in the case of YES, the following calculation is performed in the next step S13, and the inverter frequency is increased or decreased by the calculated Δ. Take control.

Δ = Kp · (ΣΔT0−ΣΔT1) In the above, Δ is the frequency to be changed, ΔT0 is the current ΔT, ΔT1 is the previous ΔT, and Kp is the proportional term coefficient (negative coefficient during heating). Then, in the next step S14, it is determined whether or not Δ obtained in the above is 0. As described above, since the upper limit of ΣΔT is 3.0, each indoor unit (A ) ~ (C)
When the absolute value of ΔT at is large, or when each room temperature is very close to the set value and is stable, the term of (ΣΔT0−ΣΔT1) becomes zero. This P control is not performed. Therefore, in such a case, the above step S14 becomes SES, and the next step S15.
Advances the I control counter by 1. On the other hand, step S1
When 4 becomes NO, that is, when P control is performed, the I control counter is cleared in step S16, and the process proceeds to step S10. And step S
At 17, it is judged whether or not the I control counter is 6 or more, that is, whether or not the P control is continuously performed 6 times or more. If NO, the process returns to step S10. On the other hand, if YES, I control is performed based on the following equation in step S18, the process returns to step S10, and the same operation is repeated thereafter.

Δ = KiΣΔT0 The above ΔT0 is the same as above, and Ki is an integral term coefficient (negative coefficient in the case of heating). That is, in step S18, control is performed so that the inverter frequency is increased in substantially proportion to ΣΔT.

When P control and I control based on ΣΔT are performed as described above, it is possible to perform fine heating capacity control in consideration of each indoor load.

Next, operation control when the bath heating operation command signal is output during the heating operation of any of the indoor units (A) to (C) or when the heating operation command signal is output during the bath heating operation The method will be described with reference to FIG. First, in step S21, it is determined whether or not there is a heating operation command signal, that is, whether the heating operation switch (36) is ON and whether the temperature detected by the indoor thermostat (37) is lower than the set temperature. When the heating operation command signal is output, in the next step S22, whether or not the bath heating operation command signal is output, that is, the bath operation switch (39) is ON, and the hot water temperature thermostat (40 It is determined whether or not the detected hot water temperature in) is lower than the set temperature. If the step S21 is NO, if the heating operation is being performed, the heating operation is stopped in step S23, the process proceeds to the next step S24, and it is determined again whether or not there is a bath heating operation command signal. To do. If step S24 is NO, it means that no operation command signal is output, so the compressor 1 is stopped in step S25. On the other hand, step S24
In the case of YES, the bath heating independent operation is performed in the next step S26. This operation is continued until the output of the bath heating operation command signal is stopped, as in step S27, and when the bath heating operation command signal is not output due to the hot water temperature reaching the set temperature, step S21. Return to.
On the other hand, if step S22 is NO, heating operation is performed in step S28, but this operation is stopped in step S21.
After returning to step S21, the room temperature reaches the set temperature.
When NO becomes NO, the process proceeds to step S23.

On the other hand, if step S22 is YES, that is, both operation command signals are output, the process proceeds to step S29, and the inverter frequency of the compressor (1) is set to the initial setting frequency in Table 1. , The maximum frequency in the corresponding total load capacity value ΣS is set, and the heating operation and the bath heating operation are simultaneously performed at this frequency for a fixed time (for example, 1 to 0.5 minutes) (step S30). Then, after the lapse of the certain period of time, in step S31, the temperature sensor (2
Whether the temperature Tc of the condensed liquid refrigerant on the outlet side of the bath heat exchanger (22) detected in 8) is Tc> T + α in relation to the hot water temperature T detected by the hot water thermostat (40). Make a decision. Note that α is a constant within the range of 2 to 5 ° C. That is, in step S31, it is determined whether or not the bath heating capacity is sufficiently larger than the required bath heating load. If the capacity is insufficient, the process proceeds to step S26, the heating operation is stopped, and the bath heating independent operation is performed as described above. on the other hand,
If it has sufficient bath heating capacity, the process proceeds to step S32 to continue the simultaneous bath heating and heating operation,
After returning to step S21, the same operation is repeated.
The heating operation (step S28), bath heating operation (step S26), and heating / bath heating simultaneous operation (step S32)
When performing, the frequency control as shown after step S12 in FIG. 5 is preferably performed.

As described above, in the heat pump system,
The inverter frequency is set to the maximum frequency corresponding to the total load capacity value ΣS, and the temperature Tc of the condensed refrigerant is detected by the temperature sensor (28) as the bath heating capacity detecting means, which is configured in steps S31 and S32. The operation control means (33) compares the detected temperature Tc with the reference value (T + α), and as a result, if the bath heating capacity is sufficient, the bath heating and the heating are simultaneously operated. ,
As compared with the case where the heating operation is uniquely stopped as in the conventional case, the heating operation frequency becomes higher, and therefore the discomfort of the heating user can be reduced. In particular, in an inverter multi-air conditioner capable of controlling the compression capacity, there is a surplus in the capacity of the compressor (1) depending on the load state on the heating side, and the probability that the bath heating can be performed with this surplus capacity. Therefore, in the inverter multi-air conditioner as described above, the capacity of the compressor (1) can be fully utilized, which can greatly contribute to comfortable air conditioning.

In the above, the heating operation command signal generation means is the room temperature thermostat (37), the bath heating operation command signal generation means is the hot water thermostat (40), the bath heating capacity detection means is the temperature sensor (28), and the operation is performed again. The control means (33) is set in step S3 in FIG.
Although it is configured by 1 and S32 respectively, it is of course possible to configure by another having the same function. In the above embodiment (Fig. 2), the temperature sensor (28) as the bath heating capacity detecting means is attached to the branch refrigerant pipe (18) portion O on the outdoor unit (X) side. As shown in FIG. 2, it may be attached to the refrigerant outlet portion P of the bath heat exchanger (22) in the bath unit (D) or to the midway portion Q of the bath heat exchanger (22). Moreover, in the above description, the bath heating capacity is detected as the condensed refrigerant temperature, but this can also be detected as the condensed refrigerant pressure at each of the positions O, P, Q, and further, the indoor heat exchanger. Portions O1, P1, Q1 corresponding to the respective positions O, P, Q of (19)
It is also possible to detect it as the temperature or pressure of the condensed refrigerant. It is also possible to detect the bath heating capacity in the bathtub unit (D) as a temperature difference between the entrance and exit (48) and (49) of the bathtub hot water to the bath heat exchanger (22). Further, as the total load capacity value grasped by the load capacity value grasping means (44), in addition to the above, each unit (A) to
It is also possible to use the operating number of (D).

(Effect of the Invention) In the heat pump system of the present invention, the compressor is operated at the maximum compression capacity corresponding to the total load capacity value when both the heating and bath heating operation command signals are output as described above. At the same time, the bath heating capacity is detected, and when the bath heating capacity is above the reference value, the heating and bath heating operations are performed simultaneously, so the heating operation frequency is higher than in the past, and therefore It is possible to reduce the discomfort of the user and perform comfortable air conditioning.

[Brief description of drawings]

1 to 6 show an embodiment of a heat pump system of the present invention. FIG. 1 is a functional system diagram, FIG. 2 is a refrigerant circuit diagram, FIG. 3 is a control system circuit diagram, and FIG. Is a flow chart of the control method on the indoor unit side, FIG. 5 is a flow chart of the control method during heating operation, FIG. 6 is a flow chart of the operation control method during bath heating operation, and FIG. It is an example refrigerant circuit diagram. (1) …… Compressor, (5) …… Inverter, (10) ……
Outdoor heat exchanger, (15) …… first electric expansion valve (expansion mechanism), (19) …… indoor heat exchanger, (22) …… bath heat exchanger, (28) …… temperature sensor (bath (Heating capacity detection means), (32) ... frequency control circuit (compressor control means),
(33) …… Operation control circuit (operation control means), (37) ……
Room temperature thermo (heating operation command signal output means), (40) ……
Hot water thermo (bath heating operation command signal output means), (44)
...... Load capacity value grasping means, (47) ...... Compression capacity storing means.

Claims (1)

[Claims] 1. An outdoor unit (X) having a compressor (1) having a variable compression capacity and an outdoor heat exchanger (10) and an indoor unit (A) having an indoor heat exchanger (19). It constitutes a refrigerant circulation circuit, and further, the indoor heat exchanger (19).
A heat pump system including a bathtub unit (D) having a bath heat exchanger (22) connected in parallel to a room, which has an operation request, and a bathtub unit (A) (D).
Load capacity value grasping means (44) for grasping the total load capacity value of the compressor, compression capacity storing means (47) for storing the maximum compression capacity of the compressor (1) corresponding to the load capacity value, and heating. Heating operation command signal generation means (37) that detects the load and issues a heating operation command signal when the heating load is greater than the reference value, and detects the bath temperature and heats the bath when the bath temperature is below the reference value. A bath heating operation command signal generating means (40) for issuing an operation command signal, a bath heating capacity detecting means (28) for detecting a bath heating capacity, and a compressor (1) when both the operation command signals are issued. A compressor operation control means (32) that operates at the maximum compression capacity in the grasped total load capacity value, and a heating operation and a bath heating operation when the detected bath heating capacity during the above operation is a reference value or more. Simultaneous operation, Heat pump system, characterized in that it comprises a driving control means (33) for the bath heating capacity to control the coolant circulation system to perform each bath heated isolated operation when it is less than the reference value.