JPS5840464A - Air conditioner - 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 The present invention relates to an improvement in a heat pump air conditioner equipped with a heat exchanger for hot water supply.

A conventional air conditioner of this type is usually configured as shown in FIG. In the figure, A is the outdoor unit of the air conditioner, and B is the indoor unit.

C indicates a hot water supply unit, and the outdoor unit A includes a compressor 1, a four-way valve 2. Outdoor heat exchanger 6° expansion mechanism 4.
Check valve 5. An outdoor blower 21 and an accumulator 9 are built in, and components other than the outdoor blower are connected by refrigerant piping as shown.

Further, in the indoor unit) B, an expansion mechanism 6, a check valve 7, and an indoor heat exchanger 8 are connected as shown in the figure by refrigerant piping. Note that 22 indicates an indoor blower.

The outdoor unit A and the outdoor unit B are connected by refrigerant pipes 15 and 16. The hot water supply unit C also includes a hot water supply heat exchanger 10. A pump 11 is built in, and the hot water supply unit C and outdoor unit A are connected to each other by refrigerant pipes 13 and 14 as shown in the figure, and the hot water supply unit C is connected to an external hot water storage tank 12 and water pipe 17.
18 and are connected as shown in the figure. In the figure, 19 indicates a water supply pipe, 20 indicates a hot water supply pipe, solid line arrows indicate the flow direction of the refrigerant during cooling, and dotted line arrows indicate the flow direction of the refrigerant during heating.

゛ The high temperature, high pressure gas refrigerant discharged from the compressor 1 during cooling operation of this conventional air conditioner is introduced from the hot water storage tank 12 by the pump 11 when passing through the refrigerant pipe 13 and the hot water supply heat exchanger 10. By exchanging heat with the hot water supply water, the hot water supply water is heated and the refrigerant is cooled. When the amount of heat exchange between the hot water supply water and the refrigerant increases, and the refrigerant exiting the hot water heat exchanger 10 becomes a high-pressure liquid/gas mixed state, the amount of refrigerant required in the refrigerant circuit increases. The amount of water is adjusted to be small so that the refrigerant exits as superheated gas without liquid at the outlet of the hot water supply heat exchanger 10. The high-pressure gas refrigerant leaving the hot water supply heat exchanger 10 is
It passes through the four-way valve 2 and is throttled by the expansion mechanism B to become a low-pressure liquid/gas mixed refrigerant, which exchanges heat with the indoor air sent by the indoor blower 22 in the indoor heat exchanger 8 and evaporates to become a low-pressure gas refrigerant. 16, the four-way valve 2, and the accumulator 9 before being sucked into the compressor 1.

In addition, when the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 during heating operation passes through the refrigerant piping 16 and the hot water heat exchanger 10, it exchanges heat with the hot water supply water sent from the hot water storage tank 12 by the pump 11. As a result, the water for hot water supply is heated and the refrigerant is cooled.

In this case, similarly to the cooling operation, the amount of water for hot water supply passing through the heat exchanger 10 for hot water supply is adjusted to a small amount so that the refrigerant exiting the heat exchanger 10 for hot water supply does not become liquid.

The high-pressure gas refrigerant that exits the hot water supply heat exchanger 10 passes through the four-way valve 2, passes through the refrigerant pipe 16, and is cooled by the passing air in the indoor heat exchanger 8 to become a high-pressure liquid refrigerant. It passes through the check valve 7, passes through the refrigerant piping 15, and is throttled by the expansion mechanism 4 to become a low-pressure liquid/gas mixed refrigerant, which is heated by the passing air in the outdoor heat exchanger 3 and evaporates, and then passes through the four-way valve 2. It is sucked into the compressor 1 via the accumulator 9. Therefore, during heating operation, only the amount of heat radiated by the hot water heat exchanger 10 is
The heat dissipation capacity of the indoor heat exchanger 8 will be reduced. In addition, the pump 1 is
When 1 is stopped, hot water cannot be supplied and only cooling or heating is performed.

The above conventional heat pump air conditioners (1) do not have a refrigerant amount adjustment device, so they cannot operate only to supply hot water; in order to supply hot water, they must operate either cooling or heating; As a result, hot water cannot actually be heated during the middle seasons when heating and cooling are not required.

(In order to prevent the refrigerant leaving the hot water supply heat exchanger 10 from becoming a liquid refrigerant, the amount of water is small. Therefore, the hot water supply capacity is small, and therefore it takes a long time to raise the water temperature in the hot water storage tank 12.

There were drawbacks such as.

The present invention was proposed for the purpose of eliminating the drawbacks of the conventional heat pump type air conditioners, and includes a compressor, a four-way valve, an outdoor heat exchanger, an expansion mechanism, a check valve, an indoor heat exchanger, In an air conditioner in which a heat exchanger for hot water supply is arranged between a four-way valve and the discharge side of a compressor of an air conditioner to which an accumulator is connected via refrigerant piping, an outdoor heat exchanger and an indoor heat exchanger are used. This relates to an air conditioner characterized in that a liquid receiver is interposed in the middle of a refrigerant liquid pipe connecting the air conditioners.

The present invention will be specifically explained below with reference to an embodiment shown in FIG.

In FIG. 2, A is an outdoor unit of an air conditioner, and A includes a compressor 1. Four-way valve 2, outdoor heat exchanger filter, expansion mechanism 4, check valve 5, outdoor blower 21. The accumulator 9 is built-in, and everything except the outdoor blower 21 is connected by refrigerant piping, which is almost the same as the above-mentioned conventional air conditioner outdoor unit (equal parts are given the same reference numerals). . Snake is an indoor unit, and the same indoor unit BK has an expansion mechanism 6, a check valve 7, and an indoor heat exchanger 8 built-in and connected by refrigerant piping, and is also equipped with an indoor blower 22. , is almost the same as the above-mentioned conventional indoor unit) B (equal parts are given the same reference numerals). C' is a hot water supply unit, and the hot water supply unit C' is different from the conventional one in that it includes a hot water supply heat exchanger 10 and a pump 11, and is connected to the outdoor unit A via refrigerant pipes 13 and 14. Although it is almost similar to the hot water supply unit C of an air conditioner, the hot water supply unit C' of the present invention has a built-in liquid receiver 26 as shown in the figure, and the liquid receiver 26 is connected to the hot water supply unit C' via a refrigerant pipe 15a. and outdoor units) A
The structure differs from the conventional air conditioner described above in that the hot water supply unit C' and the indoor unit B are connected via the refrigerant pipe 15b. The detailed structure of this liquid receiver 23 is as shown in FIG.
The height h of the tube tip in the receiver 2 filter b is set to be the same.

Note that the liquid receiver 23 may be installed in an outdoor unit A or an indoor unit B other than the hot water supply unit C'. In addition,
The hot water storage tank 12 is connected to the water supply pipe 19. It is also substantially the same as the conventional air conditioner described above in that it includes a hot water supply pipe 20 and is connected to the hot water supply unit C' through water pipes 18 and 19.

An embodiment of the heat pump air conditioner of the present invention is constructed as described above, and the air conditioner is operated as follows.

(a) Stop the pump 11 when operating only for cooling.
When the compressor is operated under the condition of Since water is not flowing, there is no heat exchange and the high temperature, high pressure gas refrigerant remains in the refrigerant pipe 14. It passes through the four-way valve 2, is cooled by the outdoor air passing through the outdoor blower 21 in the outdoor heat exchanger 3, and becomes a high-pressure liquid refrigerant, which is transferred to the check valve 5, the refrigerant pipe 15a, the liquid receiver 23, and the refrigerant pipe 151).
After that, the refrigerant is squeezed by the expansion mechanism B in the indoor/unit) B to become a low-pressure liquid/gas mixed refrigerant, which exchanges heat with the indoor air passing by the indoor blower 22 in the indoor heat exchanger 8, is heated and evaporated, and becomes a low-pressure refrigerant. It becomes a gas refrigerant. In this case, the indoor air is cooled and dehumidified by passing through the indoor heat exchanger 8. The low pressure gas refrigerant leaving the indoor heat exchanger 8 is then transferred to the refrigerant pipe 16, the four-way valve 2. It is sucked into the compressor 1 through the accurator 9.

(b) During cooling and hot water supply operation, when the pump 11 is also operated, the high temperature, high pressure gas refrigerant discharged from the compressor 1 enters the hot water supply heat exchanger 1o via the refrigerant pipe 13 as shown by the solid arrow. Here, the pump 11 causes the hot water storage tank 12 to
exchange heat with the hot water introduced via the water pipe 17,
The high temperature, high pressure gas refrigerant is cooled and the hot water is heated. This heated hot water supply water is returned to the hot water storage tank 12 via the water pipe 18, and then circulated between the hot water storage tank 12 and the hot water supply heat exchanger 100 by the action of the pump 11.
The hot water supply operation continues until the temperature of the hot water in the hot water supply unit 2 rises to a predetermined temperature. On the other hand, when the temperature of the hot water supply water is low, the refrigerant that exchanges heat with the hot water supply water in the hot water supply heat exchanger 10 and exits the hot water supply heat exchanger 10 becomes a high-pressure liquid refrigerant, and the temperature of the hot water supply water increases. As the water temperature rises, it becomes a liquid/gas mixed refrigerant, and as the water temperature rises further, it becomes a high-pressure gas refrigerant, and the refrigerant pipe 14
, enters the outdoor heat exchanger °6 via the four-way valve 2. Here, when the refrigerant exiting the hot water supply heat exchanger 10 is a liquid refrigerant, when the outdoor air temperature is low, the refrigerant is cooled in the outdoor heat exchanger filter and becomes a supercooled liquid, and when the outdoor air temperature is high, the refrigerant is cooled into a supercooled liquid. On the contrary, it is heated. The refrigerant leaving the hot water supply heat exchanger 10 is
When it is in a liquid/gas mixed state or when it is a gaseous refrigerant, the gas refrigerant is cooled by the air passing through the outdoor heat exchanger 6 and condensed, becoming a high-pressure liquid refrigerant and exiting the outdoor heat exchanger 3 into the refrigerant pipe 15a.

The liquid enters the indoor heat exchanger 8 via the liquid receiver 23 and the refrigerant pipe 15b, and thereafter operates in the same manner as during cooling.

(C) During heating-only operation (in this case, the pump 11 is in a stopped state because hot water supply operation is not performed), the high-pressure, high-temperature gas refrigerant discharged from the compressor 1 is transferred to the refrigerant pipe 13 as shown by the dotted arrow. It enters the hot water heat exchanger 10 through
Since the hot water supply water is not flowing, the hot water is not exchanged and comes out of the hot water heat exchanger 10 as a high temperature, high pressure refrigerant, and enters the refrigerant pipe 14. Four-way valve 2. The refrigerant passes through the refrigerant pipe 16 and enters the indoor heat exchanger 8. Here, the gas refrigerant is cooled and condensed by exchanging heat with the indoor air passing through it by the indoor ventilation fan 22, becoming a high-pressure liquid refrigerant, and the indoor air is heated. The high-pressure liquid refrigerant discharged from the indoor heat exchanger 8 passes through the check valve 7, the refrigerant pipe 15b, and the liquid receiver 23. Passes through the refrigerant pipe 15a,
It is throttled by the expansion mechanism 4 to become a low-pressure liquid/gas mixed refrigerant, and enters the outdoor heat exchanger 3. And here outdoor blower 2
1, the liquid/gas mixed refrigerant is heated and evaporated by exchanging heat with the outdoor air passing through it, becoming a low-pressure gas refrigerant, which is sucked into the compressor 1 via the four-way valve 2 and the accumulator 9.

(d) During heating and hot water supply operation (in this case, the pump 11 is operated), the high temperature, high pressure gas refrigerant discharged from the compressor 1 passes through the refrigerant pipe 13 as shown by the dotted line arrow to exchange heat for hot water supply. The pump 11 exchanges heat with the hot water supplied from the hot water storage tank 12, resulting in high temperature and
The high pressure gas refrigerant is cooled and the hot water is heated. The hot water heated by the hot water supply heat exchanger 10 is returned to the hot water storage tank 12 via the water piping 18, and is circulated between the hot water storage tank 12 and the hot water heat exchanger 10I:r) by the iris pump 11, and is then stored. The hot water supply operation continues until the temperature of the hot water in the tank 12 rises to a predetermined temperature. on the other hand.

When the hot water supply heat exchanger 10 leaves the hot water supply heat exchanger 10, the refrigerant becomes a high-pressure liquid refrigerant when the hot water supply water temperature is low, and when the hot water supply temperature rises, it becomes a liquid and gas mixed refrigerant, and when the water temperature further increases, the refrigerant becomes a high-pressure liquid refrigerant. It becomes a gas refrigerant, refrigerant piping 14, four-way valve 2.
The refrigerant enters the indoor heat exchanger 8 via the refrigerant pipe 16. When the refrigerant leaving the hot water supply heat exchanger 10 is a liquid refrigerant, when the indoor air temperature is low, the refrigerant is cooled and becomes a supercooled liquid, and when the indoor temperature is high, the refrigerant is cooled and becomes a supercooled liquid. , on the contrary, it is heated. When the refrigerant exiting the hot water supply heat exchanger 10 is in a liquid/gas mixed state or is a gas refrigerant, it is cooled by the passing indoor air, and the gas refrigerant is cooled and condensed to become a high-pressure liquid refrigerant, which is used for indoor heat exchange. After leaving the container 8, the same operation as during heating is performed. In this way, the heating capacity when hot water supply operation is performed at the same time as heating is smaller than the heating capacity when only heating operation is performed. The reason is that the hot water heat exchanger 1
Due to the condensing capacity at 0, the discharge pressure of the compressor 1 decreases, and the power consumption of the compressor 1 decreases. Since the required heat dissipation capacity (condensing capacity) of the sum becomes smaller and the condensing capacity is the sum of the capacity of the hot water supply heat exchanger 10 and the heating i capacity of the indoor heat exchanger 8, the hot water supply heat exchanger 10 The larger the capacity of the indoor heat exchanger 8, the smaller the heating capacity of the indoor heat exchanger 8, and the smaller the capacity of the hot water supply heat exchanger 10, the larger the heating capacity of the indoor heat exchanger 8. This is because it will always be smaller than the capacity.

(e) During operation for only hot water supply (in this case, the pump 11 is operated and the indoor blower 22 is stopped), the high temperature, high pressure gas refrigerant discharged from the compressor 1 becomes a refrigerant as shown by the dotted arrow. It enters the heat exchanger 10 for hot water supply via the piping 13. Here, the gas refrigerant exchanges heat with hot water sent from the hot water storage tank 12 by the pump 11, and the gas refrigerant is cooled and condensed to become a high-pressure cabinet refrigerant. Then the hot water is heated,
It returns to the hot water storage tank 12 via the water pipe 18, and then the pump 1
1, the hot water is circulated between the hot water storage tank 12 and the hot water supply heat exchanger 10, and hot water supply operation is performed until the temperature of the hot water in the hot water storage tank 12 rises to a predetermined temperature. Heat exchanger 10 for hot water supply
The high-pressure liquid refrigerant that exits the refrigerant pipe 14 and the four-way valve 2. The refrigerant enters the indoor heat exchanger 8 via the refrigerant pipe 16. In this case, the indoor blower 22 is stopped, so the amount of indoor air passing through the indoor heat exchanger a8 is .

Since the amount due to natural convection is very small, the amount of heat exchange is almost negligible. Therefore, the high-density liquid refrigerant exiting the indoor heat exchanger 8 is in almost the same state as the inlet state of the indoor heat exchanger 80, and the check valve 7. Refrigerant piping 15b, liquid receiver 23
．． The refrigerant passes through the refrigerant pipe 15a, is throttled by the expansion mechanism 4, becomes a low-pressure liquid/gas mixed refrigerant, and enters the outdoor heat exchanger 6. Here, the outdoor air passing through the outdoor blower 21 heats and evaporates, and the four-way valve 2. In each operation above the absorption through the accumulator 9 to the compressor 1, the receiver 26
The amount of refrigerant in the refrigerant circuit during each operation of cooling only, cooling and hot water supply, heating only, heating and hot water supply, and hot water supply only is adjusted as follows.

Now, if the total amount of refrigerant in the device is R, the total amount R is determined by the volume of the rg refrigerant and the density of the refrigerant, R=V,
becomes.

However, -R: h+ ”: ”3+ X: KV
/m3 again. The density From liquid to liquid, liquid/gas mixture x2.Gas (X
The extension of 3) and the magnitude of the change in density X are also determined by the above (
The change in the total amount H of refrigerant in the device is larger than the change due to the pressure and temperature of the refrigerant in ii), and can be considered to be mainly the change due to the state of the refrigerant in (1) above. Therefore, the amount of refrigerant in the device R
is R-Xl, v1+X2・■2+x3. (3) However, vl is the volume of liquid, and (2) is the volume of liquid/gas mixture v3 is the volume of gas.

Further, the density has a relationship of xl>X2>X3. Depending on each operation, Xl, X2. The value of X3 also changes, but this is due to the pressure and temperature of the refrigerant mentioned in (ii) above, and the change is small. The main factors that cause the amount of refrigerant to change depending on each operation are ■1
．． v2. ■This is the change in number 3.

The total amount R of refrigerant in the device becomes larger as Vl and -V2 are larger, and becomes smaller as (3) is larger.

Since V1■2■3 changes with each operation, the total refrigerant amount R changes.

The refrigerant filling amount R in the cycle is the refrigerant amount R1 during operation when the amount of refrigerant in other devices other than the liquid receiver 23 is at its maximum, and the refrigerant amount R1 during operation when the refrigerant amount in other devices except the liquid receiver 23 is at a maximum. This is the added value of the refrigerant amount R2 in the liquid receiver 23 in the filled state.

R=R1+R2 Then, the amount of refrigerant held in the liquid receiver 26 is the minimum in R2, and during other operations, more than R2 is held, and the amount of refrigerant in the device excluding the liquid receiver 23 is the minimum. At times, the amount of refrigerant held in the liquid receiver 23 reaches a maximum.

Now, if the pressure inside the liquid receiver 23 is R2, and the saturation pressure of the temperature of the liquid refrigerant at the inlet of the liquid receiver is Ps, then R2 is the condensation pressure P, the refrigerant friction pressure loss ΔPF from the condenser to the liquid receiver,
The head difference ΔPH between the condenser liquid level and the liquid receiver liquid level is determined by the pressure ΔPA that changes due to the condensation and evaporation of the refrigerant due to heat exchange between the receiver 23 and its surrounding air, p2==p, +ΔPA+ΔPH−ΔPF. .

Note that under the same operating conditions, Pl increases as the amount of refrigerant held in the condenser (refrigerant liquid level) increases, and decreases as the amount of refrigerant held in the condenser decreases.

In addition, ΔPH is when the condenser liquid level is higher than the receiver liquid level,
ΔPH＞o, when low, ΔPH<○, when the same, ΔPH:o, and ΔPF becomes larger as the amount of refrigerant circulation increases;
F>o.

In addition, when the ambient air temperature of the liquid receiver is high and the liquid refrigerant in the liquid receiver is heated and evaporated, ΔPA becomes ΔPA<0; conversely, when the ambient air temperature is low and the gas refrigerant in the liquid receiver is When is cooled and condensed, ΔPp becomes >O.

Further, Ps is determined by the refrigerant temperature at the condenser outlet, the refrigerant piping from the condenser to the liquid receiver, and the heat exchanged with the surrounding air.

Then, the refrigerant liquid level (hold contribution) in the liquid receiver 23 is Ps
(7) When P8=P2, the receiver liquid level does not change and remains stable.

(If Pa > R2, the liquid level in the liquid receiver decreases and the holding amount decreases, and gas mixes with the liquid and flows in before the expansion mechanism 4, so the throttle of the expansion mechanism 4 becomes choked. As a result, the refrigerant flow rate decreases, the refrigerant amount distribution within the device becomes concentrated in the condenser, and the supercooling of the liquid refrigerant at the condenser outlet increases, resulting in an increase in Pl. Ps=P
2, and the liquid level in the liquid receiver becomes stable.

(1) When Ps<R2, the liquid level in the liquid receiver rises (the amount of refrigerant held increases), the amount of refrigerant bold in the condenser decreases, Pl decreases, and the amount of refrigerant at the condenser outlet increases. When supercooling decreases and gas is mixed in, ΔPF increases, and becomes ~=P2, and the liquid level in the liquid receiver becomes stable.

As described above, by optimizing the ambient temperature of the liquid receiver 23, the refrigerant friction loss from the condenser to the liquid receiver 26, the difference in liquid level between the condenser and the liquid receiver, etc., it is possible to The surplus refrigerant is held in the receiver, and the receiver 23 controls the refrigerant in the device.

Since the air conditioner of the present invention has the above configuration 1 function, according to the present invention, (1) a liquid receiver 26 is provided in which the amount of refrigerant in the refrigerant circuit can be adjusted; By stopping the operation of the blower 22, only hot water supply operation became possible.

(2) It is highly reliable because it can operate only for hot water supply with a simple refrigerant circuit without using a solenoid valve or the like.

(3) It is possible to operate only hot water supply, so it is cold in the middle of the season.

Hot water can be operated even when heating is not required.

(4) Since the power consumption of the compressor 1 is reduced through the cooling and hot water supply operation, the cooling capacity is increased, and the hot water supply operation is possible, the operation has a very high coefficient of performance, and it is possible to reduce the hot water supply operation fee.

The following practical effects can be mentioned.

Next, another embodiment of the present invention shown in FIG. 3 is an example in which the compressor 1 is built in the indoor unit B. In this example, the outdoor unit A has a refrigerant pipe. Tied outdoor heat exchanger3. Expansion mechanism 4. A check valve 5 and an outdoor blower 21 are installed, and the indoor unit) B has a compressor 1° four-way valve 2. connected by refrigerant piping. Expansion mechanism 6. A check valve 7, an indoor heat exchanger 8, an accumulator 9, and an indoor blower 22 are arranged as shown in the figure, and the hot water supply unit GK also includes a hot water supply heat exchanger 10, a hot water supply pump 11. A liquid receiver 23 is arranged as shown. Then, the outdoor unit (A) and the indoor unit (B) are connected by a refrigerant pipe 24, and the outdoor unit (A)
and hot water supply unit C are connected by a refrigerant pipe 15a, and indoor unit) B and hot water supply unit) C are connected by refrigerant pipes 15b and 13-.
14, and has the same function and effect as the above embodiment. .

Further, another embodiment of the present invention shown in FIG. 4 is an embodiment in the case of a chilling unit, in which a compressor 1. Four-way valve 2. Outdoor heat exchanger 3. Expander 1It
4.6. The check valves 5, 7, the user-side heat exchanger 25, and the accumulator 9 are connected to each other via refrigerant piping as shown in the figure, and an outdoor blower 21 is also provided. 22) C has a heat exchanger 1 for hot water supply as shown in the diagram.
0. A liquid receiver 2 filter and a hot water supply pump 11 are built-in.

26 is a cooling and heating pump, 27 is a fan coil unit, and a chilling unit is provided by cold and hot water pipes 28 and 29)D
The water heat exchanger 25 is connected to the water heat exchanger 25.

In this example, the indoor heat exchanger 8 of the embodiment shown in FIG.
If replaced with , each operating method and effect.

The effect is similar to the embodiment shown in FIG.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an example of an air conditioner equipped with a conventional hot water heat exchanger, and FIG. 2 is a system diagram of an embodiment of the present invention.
3 and 4 are system diagrams of other embodiments of the present invention, respectively, and FIG. 5 is a longitudinal sectional view of a liquid receiver. 1: Compressor, 2: West valve, Ro: Outdoor heat exchanger. 4.6: Expansion mechanism 1 517: Check valve, 8: Indoor heat exchanger, 9: Accumulator, 10: Hot water supply heat exchanger, il: x pump, 12: Hot water storage tank. 13, 14.15a, 15'b: Refrigerant piping. 17.18: Water piping, 23: Receiver.

Claims (1)

[Claims] A compressor, four-way valve, outdoor heat exchanger, expansion mechanism, check valve, indoor heat exchanger, and accumulator are connected via refrigerant piping between the discharge side of the compressor and the four-way valve of an air conditioner for hot water supply. An air conditioner equipped with a heat exchanger, characterized in that a liquid receiver is interposed in the middle of a refrigerant liquid pipe connecting an outdoor heat exchanger and an indoor heat exchanger. −