JPH0781728B2 - Cooling / heating device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a cooling / heating device, and more particularly to an ice heat storage system that mainly performs heating and cooling for heating in winter and cooling in summer.

[Prior art]

Conventionally, there is a system in which cold water is manufactured at night for the purpose of cutting power peaks due to cooling in the summer and daytime, and for the purpose of reducing the refrigeration capacity, the cold water is stored, and the cooling is performed during the daytime. .

However, in this case, since the cold heat is stored only by the sensible heat of water, an enormous amount of water storage is required to cover the daytime cooling load.

For this reason, a system that stores ice instead of cold water has recently been receiving attention. In other words, since this system stores cold heat using latent heat of ice, it can store cold in about 1/10 of the volume of water, so there is also a surge in land prices in recent years.
Its spread is expected. As a result, many ice storage systems have begun to operate. Also, many proposals have been made in patent applications and the like.

[Problems to be Solved by the Invention]

However, although many ice cold storage systems have been proposed, conventional systems have various drawbacks,
It is hard to say that its spread is still sufficient. This is probably because there is no system that satisfies all the following 10 conditions required for the ice storage system.

Condition 1, a system that can be operated during the day to reduce equipment costs, and condition 2 that the IPE (ice filling rate) of the ice storage tank is large to reduce equipment costs. For that purpose, it is desirable that the dead space such as the water passage during the maximum ice making is as small as possible.

Condition 3, the heat transfer area for ice making must be small to reduce equipment costs.

Condition 4, To reduce operating costs and compressor capacity, small and medium-sized machines should be of the direct expansion type that does not use brine.

Condition 5: To reduce operating costs, the evaporator should be cooled with cold water when there is a cooling load without using ice.

Condition 6, Thick icing should not hinder the heat transfer between the evaporator heat transfer surface and water.

Condition 7, In order to prolong the life of the compressor, it is possible to avoid operation with large pressure fluctuations such as reverse cycle in summer.

Condition 8 In order to reduce maintenance costs and construction costs, cold water circulates on the load side instead of brine on small and medium-sized machines.

Condition 9, winter, hot water for heating or hot water can be heated. At that time, the heat storage tank should not become large.

Similarly to condition 10, when hot water heating in winter is also performed, there will be no problem due to the difference in the required amount of refrigerant between cooling and warm water heating.

Of course, some conventional systems satisfy some of these 10 conditions. However, among these conditions, if one condition is tried to be satisfied, it is difficult to satisfy the other conditions, and it is technically difficult and important to satisfy all of these 10 conditions. .

These 10 conditions will be described in comparison with the conventional example.

Condition 1 is an indispensable condition in the case of a normal cooling and heating load condition. That is, it is rare that the increase in the heat storage tank cost can be amortized only by reducing the operating cost without reducing the refrigeration capacity. Therefore, most of the ones currently in operation seem to satisfy this condition.

Conditions 2 and 3 are difficult conditions. One solution is a method called a dynamic system in which ice pieces or sherbet-like ice is made to flow and the ice is stored in a heat storage tank. However, in many cases, this method cannot satisfy the conditions such as Conditions 4, 7, and 8 described later.

Condition 4 is an important condition for reducing operating costs and equipment costs, but the conventional one is mostly through the brine. The reason for this is that it is difficult for the direct expansion type to satisfy the following conditions 9 and 10.

Condition 5 is proposed in the system disclosed in Japanese Patent Application No. 58-148760, and most of the systems currently implemented employ a system that satisfies this condition.

However, the system of Japanese Patent Application No. 58-148760 mentioned above does not satisfy the above-mentioned conditions, so that it is a system which is difficult to be adopted in small and medium-sized machines.

Condition 6 is also a difficult condition, and various proposals have been made. There is a method in which a part of the water in the brine is frozen to make it a dynamic method, or a method in which a reverse cycle is performed and thawing and ice making are repeated. However, the dynamic system cannot satisfy the conventional conditions 8 and 10, and the reverse cycle system cannot satisfy the condition 7 as described later.

Condition 7 is a condition for defrosting, but it is difficult to adopt the reverse cycle method, which is easy to think of. In the summer, when the reverse cycle is used, the evaporation temperature rises to 30 ° C or higher, and various research and development are required to ensure operation without problems.

Condition 8 seems to be an indispensable condition for popularizing the ice heat storage system.

As described above, it is difficult to satisfy the above conditions 1 to 8, but it is particularly difficult to satisfy the heating conditions of conditions 9 and 10.
However, if heating is not possible, rapid spread will be difficult.

The present invention has been made in view of the above points, and the above condition 1
It is an object of the present invention to provide a system that performs summer ice storage cooling and winter hot water heating that simultaneously satisfies the conditions of 10 to 10.

[Means for Solving the Problems]

In order to solve the above problems, in the present invention, the cooling / heating device is configured as follows.

A compressor, an outside air side heat exchanger, a load side condenser, a water flow-down heat exchanger, a vapor compression heat pump path constituted by a pressure reducing device and a refrigerant passage connecting these, and the load side condenser, a water flow-down type Heat exchanger, tank water pump for supplying water to the upper part of the water flow type heat exchanger, tank provided at the lower part of the water flow type heat exchanger, load fluid inlet part, load fluid outlet part and fluid connecting these In the cooling cold storage mode, the outside air side heat exchanger operates as a condenser, and the water flow type heat exchanger operates as an evaporator.
In addition, when the tank water pump is operated to cool the water sent to the water flow-down heat exchanger and freeze it, and in the load cooling mode, the outside air side heat exchanger acts as a condenser in the water flow-down type as in the cooling storage mode. When the heat exchangers operate as evaporators, respectively, and the load fluid return water flows down to the upper part of the water flow type heat exchanger, and in the heat storage mode, the outside air side heat exchanger is used as an evaporator and the water flow type heat exchanger is used. Each of the exchangers is operated as a condenser, and the tank water pump is operated to heat the water sent to the water-flow heat exchanger to heat and store the water in the tank. The side condenser as a condenser,
Each of the water-flow heat exchangers is operated as an evaporator, and the tank water pump is operated to heat the refrigerant in the water-flow heat exchanger.

[Action]

By configuring the cooling / heating device as described above, the cooling / heating device satisfies all the conditions 1 to 10 for the spread of the above-mentioned ice heat storage system, as will be described later in detail.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a flow sheet when the cooling / heating apparatus according to the present invention is used for cold storage. In the figure, the flow of the refrigerant and water is indicated by arrows. The cooling / heating device is usually grouped as a cold / hot water unit 3 in which a heat pump unit 2 is arranged on the heat storage unit 1.

As the heat pump unit 2, a mass-produced heat pump component before piping is piped for this heat pump.

During this ice making, the cold / hot water pump 4 is stopped, the four-way valve 5 is set to the "cooling normal cycle" side, the solenoid valves 6 and 6'are set to the "outside air heat exchanger" side, and the solenoid valve 27 is closed. . The outside air side heat exchanger 7 functions as a condenser, and the water flow-down heat exchanger 8 functions as an evaporator. That is, the cooling air absorbs heat from the “water” flowing down to the outside of the water flow-down heat exchanger 8 and evaporates, and the piping 9 → four-way valve 5 → solenoid valve 6 ′ → outside air side heat exchanger 7 → check valve 11 → expansion It circulates from the valve 12 to the water flow type heat exchanger 8. At this time, the fan 13 is operated and the outside air side heat exchanger 7 is cooled by the outside air. Further, the tank water pump 14 is operated, and the water under the tank 15 is sent to the header 17 through the pipe 16. A nozzle 18 is attached to the header 17, and the water in the header 17 flows down to the fin portion 19 of the water flow-down heat exchanger 8 by the nozzle 18. Then, the water is cooled in the fin portion 19 and a part of the water is frozen around the fin portion 19. The bypass control valve 21 is opened when the ice grows further and becomes thicker. This opening is controlled by the temperature detection signal from the temperature sensor 20 so that the evaporation temperature becomes 0 ° C. or higher, and a part of the refrigerant evaporated in the water flow-down heat exchanger 8 is transferred to the water flow-down heat exchanger 8. return. Alternatively, by using a bypass pipe whose evaporation temperature is 0 ° C or higher in advance,
The bypass control valve 21 may be a solenoid valve.

FIG. 2 is a pressure / enthalpy diagram for explaining the cooling cycle. A → b (compression process), b → c during ice making operation
(Condensation process), c → d (pressure reduction process), d → a (evaporation process).

The refrigeration cycle in which the bypass control valve 21 operates is e → f
→ Works like g → e. That is, the bypass control valve 21 changes the high-pressure refrigerant gas as e → f. Since the pressure at this point f is higher than the saturation pressure corresponding to 0 ° C., the ice frozen on the fin surface is thawed through the fin portion 19, and the heat cools the refrigerant gas. Is
It is point g. Then, it is compressed again by the compressor 10 and e
It becomes a point.

When the ice is thawed, the fin 13 is stopped. The reason is the third
This is because if the condenser is cooled as shown in the figure, the outside air is heated by the enthalpy corresponding to e ′ → e ″, so that the enthalpy difference f → g for defrosting is reduced.

Further, the thawed ice pieces Ip fall into the tank 15 and are stored therein.

When the water flow-down heat exchanger 8 is a direct expansion evaporator as shown in FIG. 1, the refrigerant in the evaporator is a liquid separator 8'when the ice is thawed.
After the completion of the deicing operation, the electromagnetic valve 21 'is opened, the liquid is returned to the water flow down heat exchanger 8, and then the bypass control valve 21 and the electromagnetic valve 21' are closed to restart the ice making operation. ing.

In this way, when the ice pieces Ip increase in the tank 15, the bottom of the tank 15 also becomes a layer of the ice pieces Ip at the end,
At this time, the ice making operation is automatically stopped. This stop
For example, the liquid level detection switch 22 for detecting the volume expansion of the mixture of water and ice in the tank 15 is used. There is a cylinder 26 with many small holes in the center of the tank 15 to improve the flow of water.

FIG. 4 is a flow sheet in the compressor stop cooling mode of the cooling / heating device having the above configuration. The cold / hot water pump 4 is operated, the solenoid valve 27 is opened, and the tank water pump 14, the compressor 10, and the fan 13 are not operated. The return water from the load 23 flows from the nozzle 24, the water heat exchanger 25, the electromagnetic valve 27, the header 17 and the nozzle 18 to the tank 15. Then, it is sent from the nozzle 30 to the load side via the pipe 28, the three-way control valve 29, and the cold / hot water pump 4. At this time, the three-way control valve 29 partially bypasses the load return water from the bypass pipe 31 to control the cold water temperature in the nozzle 30 to, for example, 7 ° C.

FIG. 5 is a flow sheet in the normal cooling operation mode of the cooling / heating device having the above configuration. If the vehicle is operated for a while in the state shown in Fig. 4, the deicing progresses and the water level in the tank 15 drops. For example, the liquid level detection switch 22 'is activated,
The compressor 10 is operated by switching to the normal cooling operation mode. At this time, since the water flow-down heat exchanger 8 is heated by the load return water, it is operated at an evaporation temperature of, for example, 5 ° C. However, since the load is usually larger than the refrigerator capacity, cold heat due to ice is also used, and the temperature is sent from the nozzle 30 to the load 23 at, for example, 7 ° C.

FIG. 6 is a flow sheet in the heating heat storage operation of the cooling / heating device having the above-mentioned configuration. At this time, the four-way valve 5 is switched to the normal heating cycle side, and the solenoid valve 27 is closed. The gas discharged from the compressor 10 is sent to the water-flow heat exchanger 8 through the four-way valve 5, condensed, and then the check valve 32 and the solenoid valve 6
And the pressure is reduced by the expansion valve 33. The depressurized refrigerant absorbs heat from the outside air in the outside air heat exchanger 7 and evaporates, and the four-way valve 5
And is sucked into the compressor 10 again. When the water temperature in the tank 15 rises, the operation is stopped by the temperature detection signal of the temperature sensor.

FIG. 7 is a flow sheet in the compressor stop heating mode of the cooling / heating device having the above configuration. Compressor 10, fan 1
3, the tank water pump 14 is not operated, only the hot and cold water pump 4 is operated. The solenoid valve 27 is opened. Since the temperature inside the tank 15 is 45 ° C or higher, by adjusting the three-way control valve 29,
For example, warm water of 45 ° C. or higher is sent to the load 23 side.

FIG. 8 is a flow sheet in the case of normal heating operation of the cooling / heating device having the above configuration. Normally, when the temperature detected by the temperature sensor 34 falls to 45 ° C., the four-way valve 5 is switched to the same state as the “cooling normal cycle”. In addition, solenoid valve 6,
6'is switched to the "ice heat exchanger" side. The solenoid valve 27 is also closed. Cold / hot water pump 4, tank water pump 1
4, the compressor 10 and the fan 13 are all operated. Compressor 10
The refrigerant compressed in 4 circulates the four-way valve 5-> solenoid valve 6 '-> water heat exchanger 25-> solenoid valve 6-> expansion valve 12-> water flow-down heat exchanger 8-> four-way valve 5-> compressor 10 and the tank. Hot water is heated by the water heat exchanger 25 using the water in 15 as a heat source. When the water temperature in the tank 15 drops to 0 ° C. or lower, the water can be iced to continue heating using the latent heat as a heat source.

The return hot water from the load 23 is heated by the water heat exchanger 25 and is supplied to the load 23 again through the bypass pipe 31, the three-way control valve 35, the three-way control valve 29, and the cold / hot water pump 4.

When the load 23 is small, the three-way control valve 29
The low temperature water in the heat storage tank is mixed and the hot water at 45 ° C is constantly heated. At this time, the same amount as this bypass amount is returned to the tank 15 by the three-way control valve 35.

〔The invention's effect〕

As described above, according to the present invention, in the cooling cold storage mode, the outside air side heat exchanger operates as a condenser, the water flow-down heat exchanger operates as an evaporator, and the tank water pump operates. Cooled water sent to the water flow-down heat exchanger is frozen and stored in a tank.When in load cooling mode, the outside air side heat exchanger acts as a condenser and cools down the water flow in the load cooling mode. Type heat exchangers operate as evaporators respectively, and load fluid return water is made to flow down to the upper part of the water flow type heat exchanger. In the heat storage mode, the outside air side heat exchanger is used as an evaporator and the water flow type is used. Each of the heat exchangers is operated as a condenser, and the tank water pump is operated to heat the water sent to the water-flow heat exchanger, heat and store the water in the tank, and in the normal heating mode, Using the condenser on the load side as a condenser, Each of the conditions 1 to 10 for the spread of the ice heat storage system described above because the refrigerants in the water flow-down heat exchanger are heated by operating the tanks as evaporators and the tank water pumps. Since the conditions are satisfied, the following excellent effects are obtained.

(1) Naturally, both air conditioning and heating can be operated day and night.

(2) The IPF can be increased because there is no heat transfer surface in the ice heat storage tank. Moreover, the IPF during heating is not restricted.

(3) Since the ice-making coil is not evenly arranged in the ice heat storage tank, the ice-making heat exchanger can be downsized.

(4) The evaporation temperature can be raised because the method does not involve the brine.

(5) When there is a cooling load, the evaporator is heated by the load return water, so the evaporation temperature can be raised.

(6) Since the icing does not become thick, the heat transfer performance is good.

(7) Evaporation temperature is 0 even when performing the thaw cycle.
Since the ice is thawed under operating conditions that are slightly higher than ℃, the pressure fluctuation in the suction part of the compressor is small.

(8) Since no brine is used on the load side, maintenance costs and construction costs can be reduced.

(9) Since the heat storage tank during heating is used in two stages, it is not necessary to enlarge the heat storage tank.

(10) The ice making evaporator is also small, and the required amount of refrigerant is almost the same during cooling and heating, and stable operation is possible.

(11) For the heat pump part, the main part of the mass-produced machine can be used as it is, with only a part of the piping changed, resulting in low cost.

(12) The tank water pump is not operated when there is a heating load such as cooling and heating, so operating costs can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a flow sheet when the cooling / heating device of the present invention is used for cooling storage, FIGS. 2 and 3 are pressure / enthalpy diagrams for explaining a cooling cycle, and FIG. 4 is a book. The figure which shows the flow sheet in the case of the compressor stop cooling mode of the cooling and heating apparatus of the invention, FIG. 5 is the figure which shows the flow sheet in the case of the normal cooling operation mode of the cooling and heating apparatus of this invention, and FIG. FIG. 7 is a diagram showing a flow sheet in the heating / heat storage operation of the cooling / heating device of the present invention, FIG. 7 is a diagram showing a flow sheet in the compressor stop heating mode of the cooling / heating device of the present invention, and FIG. It is a figure which shows the flow sheet at the time of normal heating operation of the cooling / heating apparatus of this invention. In the figure, 1 ... Heat storage unit, 2 ... Heat pump unit, 3 ... Cold / hot water unit, 4 ... Cold / hot water pump, 5 ...
… Four-way valve, 6,6 ′ …… Solenoid valve, 7 …… Outside air heat exchanger,
8 ... Water flow down heat exchanger, 10 ... Compressor, 11 ... Check valve, 12 ... Expansion valve, 13 ... Fan, 14 ... Tank water pump, 15 ... Tank, 18 ... Nozzle, 19 …… Fin part,
21 ... Bypass control valve, 21 '... Solenoid valve, 22,22' ...
Liquid level detection switch, 23 …… load, 24 …… nozzle, 25 ……
Water heat exchanger, 26 ... Cylinder, 27 ... Solenoid valve, 29 ... Three-way control valve, 30 ... Nozzle, 31 ... Bypass pipe, 32 ... Check valve, 33 ... Expansion valve, 34 ... Temperature Sensor.

Claims (2)

[Claims] 1. A compressor, an outside air side heat exchanger, a load side condenser,
A water compression heat exchanger, a decompression device, and a vapor compression heat pump path constituted by a refrigerant passage connecting these, a load-side condenser, the water cooling heat exchanger, and an upper portion of the water cooling heat exchanger. A tank water pump for delivering water to the tank, a tank provided under the water flow-down heat exchanger, a load fluid inlet,
It is composed of a load fluid path composed of a load fluid outlet part and a fluid passage connecting them, and in the cooling cold storage mode, the outside air side heat exchanger operates as a condenser, and as a water downflow heat exchanger, In addition, when the tank water pump is operated to cool the water sent to the water downflow heat exchanger to freeze it, and in the load cooling mode, the outside air side heat exchanger serves as a condenser in the same manner as in the cooling cold storage mode, Each of the lower heat exchangers operates as an evaporator, and the load fluid return water is caused to flow down to the upper part of the water flow-down heat exchanger, and in the heat storage mode, the outside air side heat exchanger is used as the evaporator. Each of the water-downflow heat exchangers is operated as a condenser, and the tank water pump is operated to heat the water sent to the water-downflow heat exchanger to heat and store the water in the tank. Composed Cooling and heating device, characterized in that the. 2. A compressor, an outside air side heat exchanger, a load side condenser,
A water compression heat exchanger, a decompression device, and a vapor compression heat pump path constituted by a refrigerant passage connecting these, a load-side condenser, the water cooling heat exchanger, and an upper portion of the water cooling heat exchanger. A tank water pump for delivering water to the tank, a tank provided under the water flow-down heat exchanger, a load fluid inlet,
It is composed of a load fluid path composed of a load fluid outlet part and a fluid passage connecting them, and in the cooling cold storage mode, the outside air side heat exchanger operates as a condenser, and as a water downflow heat exchanger, In addition, when the tank water pump is operated to cool the water sent to the water downflow heat exchanger to freeze it, and in the load cooling mode, the outside air side heat exchanger serves as a condenser in the same manner as in the cooling cold storage mode, Each of the lower heat exchangers operates as an evaporator, and the load fluid return water is made to flow down to the upper part of the water-flow-type heat exchanger.In the normal heating mode, the load side condenser serves as a condenser and the water flow A cooling / heating device characterized in that the lower heat exchanger is operated as an evaporator and the tank water pump is operated to heat the refrigerant in the water flow down heat exchanger.