JPH10205910A - Absorption cooling and heating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide heating which is felt suitable independent of the air volume during operation of a heat pump. SOLUTION: A condenser temperature-calculating part 20 consists of a map showing the correlation between a set temperature and the solution temperature Tc for having warm air at the set temperature and calculates the solution temperature Tc inside the condenser 9 based on an inputted set temperature. A vapor pressure-calculating part 22 has a solutionvapor pressure characteristic chart and, with a solution temperature Tc as the input, calculates the vapor pressure Pc in relation to the temperature Tc. A comparison part 23 compares the output Ps of a pressure sensor PS9 with the calculated vapor pressure Pc. On the basis of the result of the comparison by the comparison part 23, a burner adjusting part 24 controls a burner 7, for example, in a manner of increasing the amount of heating when the condenser pressure Ps in the sensing is lower than the calculated vapor pressure Pc. As a result, the air discharged from an indoor unit is maintained at a temperature corresponding to the condenser pressure Ps.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption type air conditioner, and more particularly, to a method of obtaining a suitable warm air having a desired constant heating irrespective of a change in the amount of air sent from an indoor unit. The present invention relates to an absorption type air conditioner that can be used.

[0002]

2. Description of the Related Art Conventionally, an absorption-type refrigeration type cooling device has been known. In recent years, not only a cooling operation but also a heat pump heating operation utilizing heat pumped from outside air by an evaporator can be performed. There is an increasing demand for a heating and cooling system.

For example, Japanese Patent Publication No. 6-97127 proposes an absorption type water cooler / heater which can be operated in three modes of cooling operation, heating by heat pump operation, and heating by direct fired (boiler) operation. ing.

[0004]

In the conventional air conditioner, when the heating load suddenly increases during the operation of the heat pump and the amount of hot air discharged from the indoor unit suddenly increases, the temperature of the hot air decreases and the desired temperature is reduced. On the other hand, when the feeling of heating is no longer obtained, when the discharge amount of the hot air from the indoor unit suddenly decreases, there is a problem that the temperature of the hot air rises more than necessary. In particular, it is wasteful that the temperature of the hot air is unnecessarily high, which leads to a decrease in operating efficiency.

On the other hand, even if the temperature of the hot air discharged from the indoor unit is measured and the result is fed back to obtain a certain heating sensation, the flow of the air is uneven, so the temperature is detected. There is a problem in that the results vary, and the control becomes very complicated in order to eliminate the variations in the detection results.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide an absorption-type cooling and heating apparatus which can reliably obtain an appropriate heating sensation even with a change in air flow with simple control.

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems and achieve the object, the present invention provides an evaporator for storing a refrigerant, and a solution containing an absorbent for absorbing refrigerant vapor generated in the evaporator. And a regenerator for heating the solution to extract the refrigerant vapor in order to recover the absorbent concentration of the solution, and condensing the refrigerant vapor extracted by the regenerator to the evaporator. In the absorption type air conditioning system having a condenser for supplying, in the cooling operation, the cold water passing through the evaporator is circulated to the indoor unit to discharge the cool air, and in the heat pump operation, the inside of the absorber is discharged. And a configuration in which the cooling water passed through the condenser is circulated to the indoor unit to discharge hot air, and the pressure in the condenser corresponding to a condensing temperature capable of providing the solution with a heating calorie. Maintain There is a first feature that is configured to control the heating amount of the regenerator during sea urchin heat-pump operation.

Further, the present invention is characterized in that trifluoroethanol is used as the refrigerant, and the internal pressure of the condenser is calculated within a range of 250 mmHg to 500 mmHg based on a set temperature. There are features. Further, the present invention has a third feature in that the circulation amount of the cooling water is maintained substantially constant.

According to the first to third features, the temperature of the cooling water that determines the temperature of the hot air from the indoor unit has a certain correlation with the temperature of the refrigerant liquid in the condenser that gives the calorific value to the cooling water. The desired pressure is maintained by maintaining the internal pressure of the condenser within a predetermined range.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a system block diagram showing a main configuration of an absorption type cooling and heating apparatus according to one embodiment of the present invention.
In the evaporator 1, trifluoroethanol (TF) is used as a refrigerant.
E) or the like, and the absorber 2 contains a DMI derivative (dimethylimidazolidinone) as a solution containing an absorbent. In this case, the refrigerant is not limited to the fluorinated alcohol and may be any refrigerant that can have a wide non-freezing range. The solution is not limited to the DMI derivative, but can have a wide non-crystalline range, and may be any absorbent that has a higher normal pressure boiling point than TFE and can absorb TFE. For example, a combination of water and lithium bromide is not suitable for the system according to the present embodiment because water as a refrigerant may freeze during a heating operation in a state where the outside air temperature is close to zero degrees. .

The evaporator 1 and the absorber 2 are fluidly connected to each other through an evaporating (refrigerant) passage (not shown).
When these spaces are kept under a low pressure environment of, for example, about 30 mmHg, the refrigerant in the evaporator 1 evaporates and enters the absorber 2 through the passage. The evaporating passage has a precooler 1
8 are provided. The precooler 18 functions to heat and vaporize the mist (mist-like refrigerant) remaining in the refrigerant vapor, and to lower the temperature of the refrigerant supplied from the condenser 9. The absorbent vapor in the absorber 2 absorbs the refrigerant vapor, and the absorption refrigeration operation is performed.

First, when the burner 7 is ignited and the solution concentration in the absorber 2 is increased by the regenerator 3 (the burner, the regenerator and the solution concentration will be described later), the solution in the absorber 2 absorbs the refrigerant vapor. Then, the inside of the evaporator 1 is cooled by the latent heat due to the evaporation of the refrigerant. Inside the evaporator 1, a pipe line 1a through which cold water passes is provided. One end (outlet end in the figure) of the pipeline 1a is connected to the # 1 opening of the first four-way valve V1, and the other end (inlet end in the figure) is connected to the # 1 opening of the second four-way valve V2.

The refrigerant is guided by the pump P1 to the spraying means 1b provided in the evaporator 1, and is sprayed on the pipeline 1a through which the cold water passes. The refrigerant removes heat of evaporation from the cold water in the pipe 1a to become refrigerant vapor, and flows into the absorber 2 through the evaporation passage. As a result, the temperature of the cold water in the pipe 1a drops. The refrigerant in the evaporator 1 is guided to the spraying means 1b, and a part of the refrigerant is supplied to the rectifier 6 through the filter 4 as described later. A flow control valve V5 is provided between the evaporator 1 and the filter 4.
In addition, it is preferable to use an ethylene glycol or propylene glycol aqueous solution as the cold water flowing through the pipeline 1a.

When the vapor of the fluorinated alcohol, ie, the refrigerant vapor, is absorbed by the solution in the absorber 2, the temperature of the solution rises due to the heat of absorption. The absorption capacity of a solution increases as the temperature of the solution decreases and as the concentration of the solution increases. Therefore, in order to suppress a rise in the temperature of the solution, a pipe 2a is provided inside the absorber 2, and cooling water is passed through the pipe 2a. After passing through the condenser 9 at one end (outlet end in the figure) of the pipe line 2a, the # 4 of the first four-way valve V1 is
The other end (the inlet end in the figure) of the pipeline 2a is connected to the # 2 opening of the second four-way valve V2, respectively. As the cooling water passing through the pipe 2a, the same aqueous solution as the cold water is used.

The solution is guided to the spraying means 2b provided in the absorber 2 by the pump P2, and is sprayed on the pipeline 2a. As a result, the solution is cooled by the cooling water passing through the pipe 2a. On the other hand, the temperature of the cooling water rises because it absorbs heat. The solution in the absorber 2 absorbs the refrigerant vapor, and the absorption capacity decreases when the concentration of the absorbent decreases. Therefore,
By separating and generating the refrigerant vapor from the absorbent solution by the regenerator 3 and the rectifier 6, the concentration of the solution is increased and the absorption capacity is restored.

The solution diluted by absorbing the refrigerant vapor in the absorber 2, that is, the dilute solution, is guided to the spraying means 2 b, and is also fed to the rectifier 6 through the pipe 7 b by the pump P 2 to the regenerator 3. Flow down. An on-off valve V3 is provided in a pipe 7b connecting the pump P2 and the regenerator 3. The regenerator 3 has a burner 7 for heating the dilute solution supplied from the absorber 2. The burner 7 is preferably a gas burner, but may be any other type of heating means. The solution (concentrated solution) heated by the regenerator 3 to increase the concentration by extracting the refrigerant vapor is returned to the absorber 2 through the pipe 7a. An on-off valve V4 is provided on the pipeline 7a. At this time,
The concentrated solution having a relatively high temperature is sprayed by the spraying means 2c to the pipeline 2a.
Sprayed on.

When the diluted liquid supplied to the regenerator 3 is heated by the burner 7, refrigerant vapor is generated. The absorbent solution mixed into the refrigerant vapor is separated by the rectifier 6, and the refrigerant vapor having a higher purity is fed to the condenser 9.
The refrigerant cooled and condensed and liquefied there is supplied to the pre-cooler 1
8. Returned to the evaporator 1 via the pressure reducing valve 11 and sprayed.

Although the purity of the vapor supplied from the condenser 9 to the evaporator 1 is extremely high, a very small amount of the absorbent component mixed in the refluxing refrigerant accumulates over a long operation cycle. It is inevitable that the purity of the refrigerant in the evaporator 1 gradually decreases. Therefore, as described above, only a small part of the refrigerant is supplied from the evaporator 1 to the rectifier 6 via the filter 4 so as to pass through a cycle for increasing the purity again together with the refrigerant vapor generated from the regenerator 3. It is desirable to do.

The high-temperature concentrated liquid in the pipe 7a discharged from the regenerator 3 is discharged from the absorber 2 by the heat exchanger 12 provided in the middle of the pipe connecting the absorber 2 and the rectifier 6. After being cooled by exchanging heat with the dilute solution, it is sprayed into the absorber 2. on the other hand,
The diluted liquid preliminarily heated by the heat exchanger 12 is supplied to the rectifier 6. Although the thermal efficiency is improved in this way, a heat exchanger (not shown) for transferring the heat of the concentrated liquid to be refluxed to the cooling water in the pipe line 2a coming out of the absorber 2 or the condenser 9 is further provided. The temperature of the concentrated liquid recirculated to the absorber 2 may be further reduced by providing (i), and the cooling water temperature may be further increased.

The sensible heat exchanger 14 for exchanging the cold water or the cooling water with the outside air is provided with a pipe 4a, and the indoor unit 15 is provided with a pipe 3a. One end (the inlet end in the figure) of each of the conduits 3a, 4a is at the opening # 3 and # 4 of the first four-way valve V1, and the other end (the outlet end in the figure) is the # of the second four-way valve V2.
3 and # 4 openings respectively. The indoor unit 15 is provided in a room that performs cooling and heating, and is provided with a cooling air or warm air blowing fan (both are common) 10 and a blowing outlet (not shown). The sensible heat exchanger 14 is placed outdoors, and the fan 19 forcibly exchanges heat with the outside air.

The evaporator 1 is provided with a level sensor L1 for detecting the amount of the refrigerant, a temperature sensor T1 for detecting the temperature of the refrigerant, and a pressure sensor PS1 for detecting the pressure in the evaporator 1. The absorber 2 is provided with a level sensor L2 for sensing the amount of the solution. The condenser 9 is provided with a level sensor L9 for sensing the amount of condensed refrigerant, a temperature sensor T9 for sensing the temperature of the refrigerant, and a pressure sensor PS9 for sensing the pressure in the condenser 9. The sensible heat exchanger 14, the regenerator 3, and the indoor unit 15 are provided with temperature sensors T14, T3, and T15, respectively. The temperature sensor T14 of the sensible heat exchanger 14 detects the outside air temperature,
The temperature sensor T15 of the indoor unit 15 senses the temperature of the room for cooling and heating. Further, the temperature sensor T3 of the regenerator 3 senses the temperature of the solution.

In the above configuration, during the cooling operation, the first and second four-way valves V1 and V2 are connected to the respective # 1 valves.
The opening and the # 3 openings are communicated and the # 2 and # 4 openings are communicated with each other. Thereby, the cold water whose temperature has been lowered by the refrigerant being sprayed on the pipeline 1a is guided to the pipeline 3a of the indoor unit 15 to cool the room.

On the other hand, during the heating operation, the first and second four-way valves V1 and V2 are switched to positions where the # 1 and # 4 openings are communicated and the # 2 and # 3 openings are communicated. I do. Thereby, the warmed cooling water in the pipeline 2a is guided to the pipeline 3a of the indoor unit 15 to heat the room.

If the outside air temperature becomes extremely low during the heating operation, it becomes difficult to pump heat from the outside air via the sensible heat exchanger 14, and the heating capacity is reduced. For such a case, a recirculation passage 9a and an on-off valve 17 are provided to bypass between the condenser 9 and the regenerator 3 (or the rectifier 6). That is, when it is difficult to pump up heat from the outside air, the absorption refrigeration cycle operation is stopped, the steam generated in the regenerator 3 is circulated to the condenser 9, and the heat generated by the burner 7 is transferred to the condenser 9. Thus, the temperature of the cooling water is increased by a direct fired operation in which the cooling water is efficiently transmitted to the cooling water in the pipe line 2a to improve the heating capacity.

Next, a description will be given of an operation for obtaining an appropriate feeling of heating regardless of the amount of air discharged from the indoor unit 15. The air volume of the indoor unit 15 is changed by a change in load calculated from the set temperature, the indoor temperature, and the outside air temperature. If the air flow increases due to an increase in the load, the cooling water temperature decreases and a feeling of heating cannot be obtained. Therefore, in the present embodiment, the temperature of the cooling water is maintained so that an appropriate feeling of heating is always obtained.

By the way, in the heating operation, the cooling water finally passed through the condenser 9 is supplied to the indoor unit 15.
Therefore, the temperature of the cooling water entering the indoor unit 15 is equal to the temperature of the cooling water exiting the condenser 9 ignoring the heat loss.
On the other hand, the temperature of the solution in the condenser 9 and the vapor pressure have the following relationship. FIG. 3 is a characteristic diagram showing the relationship between the temperature of the solution, the vapor pressure, and the concentration of the absorbent in the solution. Since the solution passing through the condenser 9 is 100% of the refrigerant (TFE), the relationship between the temperature and the vapor pressure of the solution is obtained from the characteristic A in FIG. As understood from this characteristic, since there is a certain correlation between the temperature of the solution and the vapor pressure, the vapor pressure of the solution for bringing the temperature of the solution to a desired value is specified.

According to experiments by the present inventors, the temperature of the cooling water discharged from the condenser 9 is set to approximately 45 ° C. to 60 ° C.
By setting the discharge temperature of the indoor unit 15 to 40 ° C.
It has been found that the temperature can be maintained at 50 ° C. Here, there is a certain correlation between the temperature of the refrigerant liquid in the condenser 9 and the temperature of the cooling water, and according to the characteristics shown in FIG.
In the range of 50 mmHg to 500 mmHg, the temperature of the refrigerant liquid is 48 ° C to 63 ° C. Therefore, if this vapor pressure range is maintained, the temperature of the cooling water is set to 45 ° C. to
0 ° C, that is, the discharge temperature of the indoor unit 15 is almost 40 ° C
~ 50 ° C.

In the present embodiment, the refrigerant condensing pressure of the condenser 9 is maintained at a predetermined value based on the above-mentioned relationship between the temperature and the vapor pressure, and as a result, the temperature of the cooling water circulated to the indoor unit 15 is maintained. I do. Specifically, the heating amount of the regenerator 3 is adjusted such that the detected pressure of the pressure sensor PS9 provided in the condenser 9 is maintained at a predetermined value while the circulation amount of the cooling water is kept substantially constant.

The main function of the control means for adjusting the heating amount of the regenerator 3 will be described with reference to a block diagram. FIG.
In, the control unit 25 can be constituted by a microcomputer. The output of the pressure sensor PS9 that senses the pressure in the condenser 9 is taken into the control unit 25. The condenser temperature calculator 20 calculates the temperature Tc of the solution in the condenser 9 based on the set temperature input from the temperature setter 21.
Specifically, a set temperature previously determined by an experiment,
The temperature Tc of the solution is obtained by using the map indicating the correlation with the temperature Tc of the solution for obtaining the hot air at the set temperature and inputting the set temperature.

The vapor pressure calculator 22 receives the temperature Tc of the solution as input and calculates a vapor pressure Pc related to the temperature Tc. Specifically, a map created based on the solution-vapor pressure characteristic diagram (FIG. 3) is used. The comparing unit 23 compares the sensed pressure Ps of the pressure sensor PS9 with the calculated vapor pressure Pc. The burner adjusting section 24 adjusts the burner 7 based on the comparison result of the comparing section 23. For example, when the detected condenser pressure Ps is lower than the calculated vapor pressure Pc, the burner 7 is controlled to increase the heating amount.

By increasing the amount of heating by the burner 7, the refrigerant vapor supplied to the condenser 9 is increased, and the condenser pressure Ps is increased. Then, the temperature of the refrigerant in the condenser 9 rises, and as a result, the air discharged from the indoor unit 15 is maintained at a temperature corresponding to the condenser pressure Ps.

As described above, according to the present embodiment, the discharge temperature of the indoor unit 15 can be maintained during the operation of the heat pump regardless of the change in the air flow due to the increase or decrease of the load. In particular, since the amount of heating of the regenerator 3 is controlled based on the condenser pressure, there is an advantage that the response to a pressure change due to heating is fast. Further, by controlling the heating amount of the regenerator 3, the pressure of the regenerator 3 itself is also maintained at a high level.
It is also possible to secure the amount of solution circulating from the filter to the absorber 2.

[0033]

As is apparent from the above description, according to the first to third aspects of the present invention, the heating amount of the regenerator can be increased even when the air volume of the indoor unit changes during the operation of the heat pump. This compensates for the temperature drop of the cooling water. In particular, since the heating amount is controlled based on the condenser pressure, the control response is fast.

According to the third aspect of the present invention, the circulation amount of the cooling water may be constant, so that the configuration of the circulation pump is simplified.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a configuration of an absorption type cooling and heating apparatus according to an embodiment of the present invention.

FIG. 2 is a functional block diagram showing a control function of the absorption type air conditioner according to the embodiment of the present invention.

FIG. 3 is a characteristic diagram showing a relationship between a solution temperature and a vapor pressure, and an absorbent concentration in the solution.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Evaporator, 2 ... Absorber, 3 ... Regenerator, 9 ... Condenser, 11 ... Pressure reducing valve, 14 ... Sensible heat exchanger, 15 ... Indoor unit, 25 ... Control part

Claims (3)

[Claims] 1. An evaporator for storing a refrigerant, an absorber for containing a solution containing an absorbent for absorbing refrigerant vapor generated in the evaporator, and an absorbent for recovering the absorbent concentration of the solution.
An absorption-type cooling and heating device having a regenerator that heats the solution to extract a refrigerant vapor and a condenser for condensing the refrigerant vapor extracted by the regenerator and supplying the condensed refrigerant vapor to the evaporator; During the cooling operation, the cold water that has passed through the evaporator is circulated to the indoor unit so as to discharge the cool air, and when the heat pump is operating, the cooling water that has passed through the absorber and the inside of the condenser is cooled by the indoor unit. A circulation path formed so as to circulate through the machine to discharge hot air; a pressure sensor for sensing a pressure in the condenser; and a temperature of the refrigerant in the condenser, and applying a heating calorie to the solution. A pressure calculating means for calculating a condenser internal pressure corresponding to the condensing temperature based on a predetermined correlation, and a pressure sensed by the pressure sensor and the pressure calculating means. An absorption type air conditioner comprising: comparison means for determining the magnitude of the determined vapor pressure; and heating amount adjustment means for controlling the heating amount of the regenerator during a heat pump operation based on the determination result by the comparison means. apparatus. 2. The method according to claim 1, wherein trifluoroethanol is used as the refrigerant, and the pressure in the condenser is 250 mmH based on a set temperature.
2. The absorption type cooling and heating apparatus according to claim 1, wherein said pressure calculating means is configured to calculate within a range of g to 500 mmHg. 3. The absorption type cooling and heating apparatus according to claim 1, wherein the circulation amount of the cooling water is maintained substantially constant.