JPH0684851B2 - Operating method of air conditioner using heat pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of application" The present invention uses a single-stage compressor at night and daytime by interposing a heat storage tank capable of storing latent heat (including cold storage) in various heat pump cycles. It relates to the operating method of an air conditioner that enables two-stage compression operation with an equal difference between the two, and in particular, the cold energy storage source obtained by using midnight power is used as the heat energy for daytime cooling and heating operation. The present invention relates to a method for operating an air conditioner using a heat pump, which is used as a heat pump to reduce heating and cooling costs.

"Conventional technology and its problems" Compared with the conventional method, the power cost is reduced by using the late-night electricity, and the two-stage compression operation by the time difference operation is performed using the single-stage compressor and the sensible heat storage tank. The operation method of the cooling and heating device that enables the cooling and heating operation at the compression ratio is
The applicant has previously proposed.

However, since the heat storage tank used in the above-mentioned prior art uses sensible heat during heating, it requires a considerably large volume in order to obtain the amount of heat storage required for daytime heating operation. In order to install a heat storage tank, because it will be installed underground from the mechanical equipment in terms of strength and heat retention, not only will the construction cost for installing an underground tank be large, but it will also be necessary to install a compressor and other mechanical equipment. The problem arises that the cost of plumbing for connecting to is likely to be quite large.

Further, the applicant previously, during the winter heating, first performs the primary compression operation of the heat pump at night by using the outside air heat source, the thermal energy is stored in the heat storage tank as latent heat of 15 ~ 25 ℃, In the daytime, the heat pump uses the latent heat energy as a heat source, and the target temperature for load heat exchange is 50 ° C.
By performing secondary compression operation up to the vicinity, a heating system is configured by an operation method that is substantially similar to the two-stage compression operation with a time difference, while during summer cooling, the refrigerator mainly operates at night and the ice latent heat We have proposed a cooling and warming system that performs cooling by performing heat storage and exchanging the stored heat energy with the cooling load during daytime cooling.

However, in such an air conditioning system, 15-25
A heat storage tank for storing heat storage near ℃ and a heat storage tank for storing cold as ice heat storage are required, or two or two categories of heat storage tanks, and each heat storage tank is used only in either the summer or winter seasons. In addition, there is a problem that it is extremely inefficient and the installation area of the heat storage tank is required to be approximately doubled.

In order to eliminate such drawbacks, the present applicant encapsulates the latent heat storage agent, and the ice latent heat storage agent in a single heat storage tank,
Although latent heat storage agents having a melting point of around 25 ° C are mixed and stored, the disadvantage that the heat storage tank becomes large and complicated cannot be solved even with such a configuration.

Further, in the cooling and heating system, during summer cooling, an operation similar to a substantial two-stage compression operation due to an efficient time difference is performed while using inexpensive late-night power, and
In the heat storage tank using the outside air heat source having a temperature of around 30 ℃,
In order to take the configuration of the single-stage compression operation in which cold is stored as ice latent heat of 0 ° C or less, the temperature difference Δt between the condensation temperature and the evaporation temperature of the refrigerant is
The temperature is around 40 to 50 ° C, the compression ratio becomes considerably large, and the power consumption increases in proportion to this.

A technical problem to be solved by the present invention is to perform a two-stage compression operation by a heat pump cycle similar to a two-stage compression operation with a time difference using a heat storage tank capable of storing latent heat (including cold storage) and a single-stage compressor. Therefore, it is an object of the present invention to propose an operation method of an air conditioner using a heat pump applied as a cooling and heating system, which effectively utilizes heat energy.

Another object of the present invention is to enable the use of a common heat storage tank together with a substantial two-stage compression operation due to a time difference in both summer cooling and winter heating, and as a result, it is possible to use a midnight power and a low compression ratio. By using a common heat storage tank for both cooling and heating, the cooling and heating system achieves a large volume reduction and construction cost reduction. It is an object of the present invention to provide an operating method of an air conditioner using a heat pump applied as above.

[Means for Solving Problems] In order to achieve the technical problem, the present invention provides a single-stage compressor for refrigerant compression, and an evaporator that takes in an external air heat source or load to evaporate or condense the refrigerant. Equipped with a condenser and a heat storage tank that can store latent heat with an intermediate temperature range of approximately 15 to 25 ° C, which is located approximately midway between the temperature of the outside air heat source at night or day and the target temperature for heat exchange with the load, as the melting point. Using an air conditioner that constitutes a heating / cooling system, during the cooling cycle, the outside air heat source at night is guided to the condenser side, while the evaporator side heat-exchanges with the heat storage tank,
After performing primary compression operation to approximately the intermediate temperature range using the outside air heat source at night and storing it in the heat storage tank as latent heat having a melting point near 15 to 25 ° C in the intermediate temperature range, the latent heat is condensed in the daytime. On the other hand, while performing secondary compression operation while exchanging heat with the load on the evaporator side, obtaining heat energy for cooling,
On the other hand, during the heating cycle, the outside air heat source at night is guided to the evaporator side, while the condenser side is performing heat exchange with the heat storage tank, while using the outside air heat source at night to perform the primary compression operation up to about the intermediate temperature range. After the heat energy having a melting point near 15 to 25 ° C in the intermediate temperature range is stored in the heat storage tank as latent heat, the latent heat is guided to the evaporator side during the daytime, while the heat is exchanged with the load on the condenser side. We propose a method of operating an air conditioner using a heat pump, which is characterized in that the secondary compression operation is performed to obtain heat energy for heating.

And in such technical means, a heat storage tank is formed by stacking cylindrical, spherical or other capsules formed of a resin system or a metal having good thermal conductivity in which a latent heat storage agent having a melting point at an intermediate temperature in two-stage compression is filled. Along with forming the latent heat storage agent enclosed in the capsule, the melting point of the latent heat storage agent is varied from approximately 15 ° C to 25 ° C to enable latent heat storage of a plurality of melting points. It is also advantageous from the standpoint of thermal efficiency that it is possible to form a latent heat storage tank whose melting point is not in a single fixed temperature but in a plurality of continuous temperature ranges, and which can be easily exchanged.

"Action" That is, the action and effect will be described in terms of numbers using the Mollier diagram of Fig. 5. A. During summer cooling For example, a single stage using an outside air heat source with an outside air temperature of around 40 ° C during the day When daytime cooling (load chilled water temperature of 5 to 7 ° C) is performed in the compression operation, the condensing temperature of the refrigerant (R-22) is about 50 ° C, and the evaporation temperature is about 0 ° C. The compression ratio is around 3.9-4.0 as shown by the dotted line in).

In addition, if the outside heat source at night (outside air temperature is around 30 degrees Celsius) is used to store cold by ice latent heat and the stored heat energy is exchanged with the cooling load during daytime cooling, Since the condensation temperature of (R-22) is about 40 ° C and the evaporation temperature is about -5 to -10 ° C, its compression ratio is 3.9.
It is around 4.4, and there is no significant difference in operating efficiency from the conventional technology.

On the other hand, according to the present technical means, when the latent heat storage of about 15 ° C. is performed using the outside air heat source (the outside air temperature is about 30 ° C.) at night, the compression operation of the first stage (of the two-stage compressor) Due to the high-stage side compression operation), the condensation temperature of the refrigerant (R-22) is about 40 ° C, and the evaporation temperature is about 5-10 ° C, so it is shown by the double line in Fig. 5 (A). The compression ratio is around 2.3-2.7, and the latent heat is guided to the condenser side during the daytime.
The compression ratio when performing the compression operation of the stage (corresponding to the low-stage compression operation of the two-stage compressor) is such that the condensation temperature of the refrigerant (R-22) is about 20 ° C and the evaporation temperature is about 0 ° C. Therefore, as shown by the solid line in FIG. 5 (A), the compression ratio is around 1.8 to 1.9, which is extremely low as compared with any of the above-mentioned conventional techniques, and consumes less power. It is possible to obtain heat energy for cooling at a desired temperature while effectively utilizing nighttime electric power.

B, During winter heating For example, when daytime heating (load hot water temperature of about 40 ° C) is performed by single-stage compression operation using an outside air heat source with an outside air temperature of about 0 ° C, the evaporation temperature of the refrigerant (R-22) Is about -5 to -10 ° C and the condensing temperature is about 50 ° C, the compression ratio is about 4.6 to 5.5 as shown by the dotted line in Fig. 5 (B).

On the other hand, according to the present technical means, when the latent heat storage of about 15 ° C. is performed using the outside air heat source at night (outside air temperature is about −5 to −10 ° C.), the evaporation temperature of the refrigerant (R-22) Is about −10 to −
Since the condensation temperature is around 15 ° C and the condensation temperature is around 20 ° C, the compression ratio is around 2.5-3.1 as shown by the solid line in Fig. 5 (B), and the latent heat is conducted to the evaporator side during the daytime. The compression ratio when performing the second-stage compression operation corresponding to the high-stage compression operation of the two-stage compressor is such that the evaporation temperature of the refrigerant (R-22) is disturbed.
Since the condensing temperature is around 50 ℃ at 10 ℃, Fig. 5 (B)
As shown by the double line, the compression ratio is around 2.6, which is extremely low compared to any of the conventional techniques described above.
Similar to the above, it is possible to obtain the cooling thermal energy at a desired temperature while consuming less power and effectively utilizing the nighttime electric power.

That is, according to the present technical means, the melting point of the latent heat storage layer is the intermediate temperature range located between the nighttime or daytime outside air heat source temperature and the target temperature for heat exchange with the load, in other words, the two-stage compressor. Since the temperature equivalent to the temperature range of the intercooler is set to the intermediate temperature range, by using the single-stage compressor twice through the time difference in both cooling and heating, the effect of low compression ratio This enabled efficient two-stage compression operation.

Moreover, according to the present technical means, a common heat storage tank can be used in both summer cooling and winter heating, and a single stage compressor can be used to perform a substantial two-stage compression operation due to a time difference. It is possible to operate at a low compression ratio with the use of electric power, and it is possible to use a common heat storage tank for both cooling and heating, reducing power cost and power consumption, and reducing the volume and construction of cooling and heating equipment. The cost can be significantly reduced.

Further, according to the present technical means, it is possible to use a latent heat storage tank having a common melting point temperature which is common during cooling and heating.
Along with the smaller volume of the cooling and heating equipment and the smaller size of the cold storage heat tank, there is no problem with the strength of the building even if it is installed on the roof of a building, etc., the construction cost is greatly reduced, and the pump power for pumping water is unnecessary. It is possible to achieve simplification of piping, etc., and it is possible to significantly reduce operating costs and maintenance costs.

[Embodiment] Hereinafter, a preferred embodiment of the present invention will be exemplarily described in detail with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described in this embodiment are not intended to limit the scope of the present invention only thereto, but merely illustrative examples. Nothing more than.

FIG. 3 shows a cold storage heat tank 6 used in the present invention, in which spherical balls 62 having a diameter of approximately 30 to 80 mm are stacked and filled in the tank 6, and a spray section 61 is arranged on the upper portion of the tank 6. Spray part 61
The fresh water or brine further flowing down is filled in the spherical balls 62 and is configured to circulate between the heat exchangers 3 and 4 described later while exchanging heat with the latent heat storage agent 63.

Further, in the spherical ball 62, a latent heat storage agent 63 containing Cacl ₂ 6H ₂ O and other components is enclosed, and its melting point is set to, for example, 10 to 30 ° C., preferably about 15 to 25 ° C. There is.

Incidentally, the latent heat storage agent 63 may be a single type, or by mixing a catalyst, the melting point is 15-18 ° C, 19-22 ° C, 23-
The spherical balls 62 formed at 25 ° C. and filled with such a latent heat agent may be sequentially laminated and arranged in three stages.
With this structure, the heat exchange efficiency is improved.

FIGS. 1A to 2B show an embodiment of the present invention using such a cold storage layer 6, wherein 1 is a single-stage compressor for compressing a refrigerant, and 3 and 4 are built-in heat exchangers as condensers and evaporators. In the functioning heat exchanger, one heat exchanger 3 is connected to a cooling and heating load via a branched pipe. Reference numeral 5 denotes an outside air heat source type heat exchanger that takes in an outside air heat source and exchanges heat with the refrigerant, and functions as a condenser and an evaporator.

11 to 17 are three-way switching valves, and 18 is a four-way switching valve.
By switching 18 as appropriate, the cooling and heating cycle described later is configured. Numerals 19 and 21 are circulation pumps for circulating brine composed of fresh water or antifreeze, and numerals 21 to 27 are switching valves for refrigerant or brine.

A solar water heater 7 is connected to the spray section 61 of the heat storage tank 6, and warms the fresh water or brine together with the compressor 1 in the solar water heater 7 during warming of the fresh water or brine in winter. The load on the machine 1 is reduced and the power cost is reduced.

Next, the operation based on such a configuration will be described separately for summer cooling and winter heating. In addition, the arrow line shown by the solid line in the figure shows the actual flow path.

A) During summer cooling A-1) Thermal energy heat storage at night (see FIG. 1A) First, the circulation path of the refrigerant will be described. The refrigerant compressed by the compressor 1 is an outside air heat source heat exchanger 5 (condenser). )
After entering the inside and condensing there, it is evaporated and vaporized in the heat exchanger 3 (evaporator) through the expansion valve 28, and the fresh water or brine circulating between the heat exchanger 3 and the heat storage tank 6 is cooled. , Compressor 1
Return to and repeat this.

And the fresh water or brine cooled in the heat exchanger 3 is
It is circulated and sprayed in the heat storage tank 6 from the spray section 61, and the latent heat storage agent 63 in the spherical balls 62 is cooled and solidified, so that the latent heat and sensible heat of about 15 to 25 degrees Celsius are included in the heat storage tank 6 at 15 to 25 degrees Celsius. Cold energy is stored in the area.

Therefore, in such a compression operation, since the condensation temperature of the refrigerant (R-22) is about 40 ° C and the evaporation temperature is about 5-10 ° C, the compression is performed as shown by the double line in Fig. 5 (A). The ratio is around 2.3 to 2.7, which is a low-pressure compression operation equivalent to the high-stage compression operation of the two-stage compressor, and the compression operation efficiency is improved.

A-2) Cooling operation during the daytime (see Fig. 1B) During the daytime, the four-way switching valve 18 is heated from the outside heat source heat exchanger 5 to the heat exchanger 4 side, and the three-way switching valves 15 and 16 are heated from the heat exchanger 3. After switching to the exchanger 4 side, the following cooling operation is performed.

First, the refrigerant that has exchanged heat with the cold water on the cooling load 2 side in the heat exchanger 3 (evaporator) is compressed by the compressor 1 and then enters the heat exchanger 4 (condenser) where the spherical balls After the latent heat in 62 is released, heat is exchanged with the fresh water or brine circulating between the heat exchanger 4 and the heat storage tank 6 to condense at a lower condensing temperature than that of the outside air heat source type heat exchanger 5, and then the expansion valve 28 is turned on. After evaporating and evaporating in the heat exchanger 3 (evaporator) to cool the cold water on the cooling load 2 side, the process returns to the compressor 1 and this is repeated thereafter.

In this case, since the latent heat of 15 to 25 ° C is stored in the heat storage tank 6, and the compression ratio in the daytime is such that the condensation temperature of the refrigerant (R-22) is about 20 ° C and the evaporation temperature is about 0 ° C. Since it is before and after, the compression ratio is around 1.8 to 1.9 as shown by the solid line in FIG. 5 (A), and the refrigeration cycle with a low compression ratio corresponding to the low-stage compression operation of the two-stage compressor is constructed. As a result, as described above, the two-stage compression with a substantially time difference is performed, and since the outside air heat source that should be the basis is the night outside air temperature that is significantly lower than the daytime outside air heat source, The compression ratio can be set to be significantly lower than in the case of performing the cooling by using the outside air heat source than in the case of performing the operation by the two-stage compressor by using the outside air heat source during the day as well as in the case of the single-stage compression operation.

B) During winter heating B-1) Thermal energy heat storage at night (see Fig. 2A) During nighttime operation during winter heating, the outside heat source heat exchanger 5 is used as an evaporator and the heat exchanger 3 is used as a condenser. In order to function as, the three-way switching valves 11 to 14 and the four-way switching valve 18 are switched, respectively, and after the three-way switching valves 15 and 16 are configured to circulate fresh water or brine between the heat exchanger 3 and the heat storage tank 6,
Latent heat storage at an intermediate temperature of 15 to 25 ° C. is performed in the heat storage tank 6 as described below.

That is, the compressor 1 is operated at night by the heat pump operation, and the refrigerant absorbed by the outside air heat source type heat exchanger 5 (evaporator) is compressed by the compressor 1 and then circulated in the heat exchanger 3 (condenser). It exchanges heat with the accumulated water or brine to release condensation heat energy.

Then, the warmed fresh water or brine is sprayed 61
By being sprayed more, the latent heat storage agent enclosed in the spherical balls 62 has thermal energy equivalent to the intermediate temperature on the low stage side in the two-stage compressor including latent heat and sensible heat of about 15 to 25 ° C. The heat is stored.

That is, in order to perform latent heat storage of about 15 ° C using an outside air heat source with an outside air temperature of about -5 to -10 ° C, the evaporation temperature of the refrigerant (R-22) is about -10 to -15 ° C The temperature reaches about 20 ℃, and the compression ratio is about 2. as shown by the solid line in Fig. 5 (B).
It will be around 5 to 3.1, and can be operated at a compression ratio equivalent to the low-stage compression process of a two-stage compressor.

B-2) Daytime heating operation (see Fig. 2B) In the daytime, the four-way switching valve 18 heats the outside heat source heat exchanger 5 to the heat exchanger 4 side, and the three-way switching valves 15 and 16 heats the heat exchanger 3. After switching to the exchanger 4 side, the following heating operation is performed.

First, the compressor 1 is heated by the heat pump operation,
The refrigerant that has exchanged heat with the hot water on the heating load 2 side in the heat exchanger 3 (condenser) is evaporated and vaporized in the heat exchanger 4 (condenser) via the post-expansion valve 29, where the heat Exchanger 4 and heat storage tank 6
After absorbing the latent heat in the spherical balls 62 through the fresh water or brine circulating between them, it returns to the compressor 1 and this is repeated thereafter.

As a result, a heat pump cycle that heats the hot water for heating load on the heat exchanger 3 side to about 50 ° C by using the heat energy including latent heat and sensible heat of about 15 to 25 ° C stored by the nighttime operation as a heat source is configured. The second stage compression operation, which corresponds to the high-stage compression operation of the two-stage compressor, can be performed during the day. The compression ratio in that case is that the evaporation temperature of the refrigerant (R-22) is about 10 ° C. Since the condensing temperature is around 50 ° C, the compression ratio is around 2.6 as shown by the double line in Fig. 5 (B), and the heating operation can be performed by the compression operation at a low pressure ratio.

FIG. 4 shows a cooling and heating system which is configured to perform the above-mentioned action by switching two four-way switching valves without using a three-way switching valve, and which simplifies the circulation path of the refrigerant and fresh water and reduces the number of parts. A schematic explanatory view is shown, and the difference from the above embodiment will be mainly described. 1'is a compressor, 3'is a heat exchanger (secondary chiller / heater) for exchanging heat with circulating water on the side of an air conditioner 2 '. ,
Reference numeral 4'denotes a heat exchanger (primary chiller / heater) for exchanging heat with fresh water or brine circulating between the latent heat storage tanks 6 ', 5'an outside air heat source type heat exchanger, and 8'a liquid receiver.

41-44 are all open / close valves, which are used to store energy at night.
The outside air heat source type heat exchanger 5'side and the heat exchanger (secondary chiller / heater) 3'side during cooling / heating operation during the daytime are opened. 45 and 46 are all four-way switching valves, and by appropriately switching the four-way switching valves 45 and 46 during cooling or heating,
Outside air heat source type heat exchanger 5 ', heat exchanger (secondary water heater)
3'and the heat exchanger (primary chiller / heater) 4'are configured to function as a condenser and an evaporator, respectively.

Incidentally, 47 is an expansion valve and 48 is a pump.

Even with this configuration, the same operation as in the first embodiment can be performed, and the circulation path can be simplified without using the three-way switching valve.

"Effects of the Invention" As described above, according to the present invention, a common heat storage tank capable of storing latent heat is used, and the latent heat storage temperature is used for heat exchange between a nighttime or daytime outside air heat source temperature and a load. Since the temperature is set to an intermediate temperature range located between the temperatures, it is possible to perform a two-stage compression operation with a time difference using a single-stage compressor, and it is possible to effectively utilize heat energy.

In particular, by applying the present invention to an air-conditioning system, it is possible to operate at a low compression ratio with the use of late-night electric power, reduce power cost and power consumption, reduce the volume of the entire system, and significantly reduce construction cost. It will be possible.

It has various remarkable effects.

[Brief description of drawings]

FIGS. 1A to 2B each show a schematic explanatory view of an air conditioning system according to an embodiment of the present invention, and FIG. 1A shows a thermal energy heat storage cycle at night during summer cooling (high-stage compression operation), and FIG. 1B. Is the daytime cooling operation cycle (low-stage compression operation), Figure 2A is the nighttime heat energy storage cycle during winter heating (low-stage compression operation), and Figure 2B is the daytime heating operation cycle (high-stage compression operation). Show each. FIG. 3 is a schematic sectional view of the cold storage heat tank used in each of the above-mentioned embodiments. FIG. 4 is a schematic explanatory view of an air conditioning system according to another embodiment of the present invention. FIG. 5 is an action diagram using a Mollier diagram for explaining the action of the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Keisuke Kasahara 3-6-11 Shirasagi, Nakano-ku, Tokyo (72) Inventor Tadakichi Saeki 146 Aramachi, Sendai City, Miyagi Prefecture (72) Ikuo Kasahara Gifu City, Gifu Prefecture 26, Nakashinmachi (56) Reference JP-A-58-133542 (JP, A) JP-A-58-193035 (JP, A) JP-A-53-55547 (JP, A) JP-B-57-36506 (JP , B2)

Claims (2)

[Claims] 1. A single-stage compressor for compressing a refrigerant, an evaporator and a condenser that take in an outside air heat source or a load to evaporate or condense the refrigerant, a nighttime or daytime outside air heat source temperature, and heat exchange with a load. Approximately 15 ℃, which is located approximately in the middle of the target temperature for
From an air conditioner that constitutes a cooling / heating cycle, which has a heat storage tank that can store latent heat with an intermediate temperature range of 25 ° C to While exchanging heat with the heat storage tank on the side,
After performing primary compression operation to approximately the intermediate temperature range using the outside air heat source at night and storing it in the heat storage tank as latent heat having a melting point near 15 to 25 ° C in the intermediate temperature range, the latent heat is condensed in the daytime. On the one hand, the secondary compression operation is carried out while exchanging heat with the load on the evaporator side to obtain heat energy for cooling, and on the other hand, during the heating cycle, the outside air heat source at night is guided to the evaporator side, and one condenser While exchanging heat with the heat storage tank on the side, the primary air compression operation is performed up to approximately the intermediate temperature range by utilizing the outside air heat source at night, and the heat energy having a melting point near 15 to 25 ° C in the intermediate temperature range is used as latent heat. After being stored in the heat storage tank, the latent heat is introduced to the evaporator side in the daytime, and the secondary compression operation is performed while the heat is exchanged with the load on the condenser side to obtain the heat energy for heating. Empty with a heat pump Apparatus method of operation 2. The heat storage tank is formed by stacking capsules made of a resin system or a metal having good thermal conductivity, in which a latent heat storage agent having a melting point in the intermediate temperature range is sealed, and sealed in the capsule. The melting point of the latent heat storage agent
The method for operating an air conditioner using a heat pump according to claim 1, wherein the heat storage tank is a heat storage tank in which latent heat storage of a plurality of melting points is made possible by differentiating between them.