JPH10185344A - Absorption type cooling-heating equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide absorption type cooling-heating equipment which simplifies switchover of a cooling operation, a heat pump operation and a direct fired heating operation, enables execution of a heating operation of high efficiency by a heat pump cycle and can continue the heating operation, without lowering a heating capacity, by the switchover to the direct fired heating operation at a low outdoor air temperature. SOLUTION: This absorption type cooling-heating equipment has an absorber 2 absorbing refrigerant vapor generated in an evaporator 1 and generating absorption heat, a regenerator 3 extracting a refrigerant in a solution and recovering the concentration of an absorbent, a condenser 9 of the extracted refrigerant, a first pipeline 1a for cold water disposed in the evaporator 1, a second pipeline 2a for cooling water disposed in the absorber 2 and the condenser 9 and a third pipeline 3a supplied with one of the cold water and the cooling water, has an indoor machine 15 blowing air for cooling-heating indoors and a fourth pipeline 4a supplied with the other of the cold water and the cooling water and is equipped with a sensible heat exchanger 14 exchanging heat with outdoor air. The equipment has four-way valves V1 and V2 through which the first and second pipelines 1a and 2a are connected to the third and fourth pipelines 3a and 4a respectively at the time of cooling and to the fourth and third pipelines respectively at the time of heating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption type heating and cooling apparatus, and more particularly to a heating operation mode in which a heat pump can perform a high-efficiency heating operation and a low outside air temperature makes it difficult to pump heat. However, by switching to the direct heating operation, the heating operation can be performed without lowering the heating capacity, and the absorption heating and cooling system can easily switch between the cooling operation, the heat pump operation, and the direct heating and heating operation. Related to the device.

[0002]

2. Description of the Related Art This type of absorption chiller is usually used exclusively for cooling.
There is an increasing demand for a cooling and heating device that can perform a heat pump heating operation by utilizing heat pumped by an absorber.

[0003] JP-B 1-47714, JP-A-6-67714
Japanese Patent Publication No. 2980, Japanese Patent Publication No. Hei 7-96977, and the like propose an absorption heat pump device and an absorption chiller / heater which can be commonly used for cooling and heating. 6-9712
No. 7 discloses an absorption type air conditioner which can be operated in three modes of a cooling operation, a heating operation by a heat pump cycle, and a heating operation by direct heating.

[0004]

In the above-mentioned conventional air-cooled absorption air conditioner, the configuration for switching from the cooling operation to the heating operation or vice versa becomes very complicated.
There is a problem that it is extremely difficult to use for heating operation.

For example, in the apparatus disclosed in Japanese Patent Publication No. 6-97127, it is necessary to switch the refrigerant flow path or the absorbent solution flow path when switching between the cooling operation mode and the heat pump operation mode. Will be mixed with the absorbent solution. For this reason, the switching mechanism between the three operation modes of cooling / heat pump heating / open flame heating / heating becomes extremely complicated. Further, in the apparatus disclosed in Japanese Patent Publication No. 1-77714, the four-way valve is used for switching between the cooling and the heating to simplify the flow path switching. However, the switching between the refrigerant flow path and the absorbent solution flow path is still required. In addition, since the refrigerant liquid and the absorbent solution are mixed at the time of the switching, there is a problem that it takes time to exhibit the predetermined performance after the switching.

[0006] The present invention solves the above problems, the refrigerant and the absorbent solution are not mixed when switching between the cooling / heat pump heating operation mode, and the switching between the heat pump operation and the direct heating operation mode is simple. It is an object of the present invention to provide an absorption type cooling and heating device which can be realized with a simple configuration.

[0007]

SUMMARY OF THE INVENTION The present invention provides an evaporator for containing a refrigerant, an absorber for containing a solution containing an absorbent that absorbs refrigerant vapor generated in the evaporator and generates heat of absorption, A regenerator that heats a part of the solution to extract the refrigerant vapor and recovers the absorbent concentration in the solution, and a condenser that condenses the extracted refrigerant vapor and supplies it to the evaporator,
A first pipe disposed in the evaporator and cooled therein by a refrigerant in the evaporator, and a cooling water disposed in the absorber and the condenser and passing through the interior. A second pipeline that is heated by heat exchange between the solution in the absorber and the refrigerant vapor in the condenser, an indoor unit for blowing air for cooling and heating into the room, and the indoor unit, A third pipe line for selectively passing one of the cold water and the cooling water, a sensible heat exchanger for exchanging heat between one of the cooling water and the cold water and the outside air, and disposed in the sensible heat exchanger; A fourth pipe for selectively passing the other of the cold water and the cooling water; a fourth pipe having one end of each of the first and second pipes and one end of each of the third and fourth pipes connected to the opening thereof; A four-way valve, the other end of each of the first and second conduits, 3 and the other end of the fourth conduit; and a second four-way valve connected respectively to the opening. In the first and second four-way valves, the first and second pipes are connected to the third and fourth pipes respectively in the cooling operation mode, and the first and second pipes are connected in the heating operation mode. Switching control is performed so as to be connected to the fourth and third conduits, respectively.

[0008] Further, a reflux path fluidly connecting the condenser and the regenerator is further provided, so that when the heat pump cycle heating operation cannot be performed, the refrigerant vapor generated from the regenerator is returned from the condenser to the reflux path. The heating operation can be continued by direct flame heating circulated to the regenerator via the path.

[0009]

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 a fluorinated alcohol such as DMI such as dimethylimidazolidinone in the absorber 2 as a solution containing an absorbent.
A derivative is contained. In this case, the refrigerant is not limited to the fluorinated alcohol, and may be any one that can have a wide non-freezing range. The solution is not limited to the DMI derivative, and can have a wide non-crystalline range, and has a higher normal pressure boiling point than TFE. Any absorbent may be used as long as it has TFE and can absorb TFE. For example, the combination of water and lithium bromide may cause the water as a refrigerant to freeze due to a decrease in the temperature of the solution during a heating operation in a state where the outside air temperature is close to zero degrees. It is hard to say that it is suitable.

The evaporator 1 and the absorber 2 are fluidly connected to each other through an evaporating (refrigerant) passage. When these spaces are maintained under a low pressure environment of, for example, about 30 mmHg, the evaporator 1 has The refrigerant evaporates and enters the absorber 2 through the passage as indicated by a double arrow in the figure. When the refrigerant vapor is absorbed by the absorbent solution in the absorber 2, an absorption refrigeration operation is performed. A cooler (heat exchanger) 18 is disposed in the evaporating passage.

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 converts the refrigerant vapor. The inside of the evaporator 1 is cooled by the latent heat due to the absorption and 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 conduit 1a is connected to the # 1 opening of the first four-way valve V1, and the other end (the inlet end in the figure) is connected to the # 1 opening of the second four-way valve V2 (FIG. 2, 3). 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 5. As a result, the temperature of the cold water drops. The refrigerant in the evaporator 1 is guided to the spraying means, and a part of the refrigerant is also supplied to the rectifier 6 through the filter 4 as described later in detail. A flow control valve V5 is provided between the evaporator 1 and the filter 4.
Is provided. 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, that is, 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 by a pump P2 to a spraying means 2b provided in the absorber 2, and is sprayed on a 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,
The regenerator 3 and the rectifier 6 separate and generate refrigerant vapor from the absorbent solution, thereby increasing the concentration of the solution and recovering the absorption capacity.

The solution diluted by absorbing the refrigerant vapor in the absorber 2, that is, the dilute solution, is guided to the spraying means 2b by the pump P2, and is also fed to the rectifier 6 through a pipe 7b to be regenerated. Flow down to The regenerator 3 has a burner 7 for heating the dilute solution. Although the burner 7 uses a gas burner, any heating means may be used. The solution (concentrated liquid) heated by the regenerator 3 to increase the concentration by extracting the refrigerant vapor is returned to the absorber 2 through a pipe 7a, and the concentrated liquid is supplied to the pipe 2a by the spraying means 2b. Sprinkled on top.

When the diluted liquid supplied to the regenerator 3 is heated by the burner 7, refrigerant vapor is generated. When the refrigerant vapor sufficiently contacts the solution flowing down the rectifier 6 when rising inside the rectifier 6, a small amount of the adsorbent solution component mixed therein is sufficiently separated. Is sent to The refrigerant cooled and liquefied by the condenser 9 passes through the pipe 9b,
It is returned to the evaporator 1 via the cooler 18 and the pressure reducing valve (flow control valve) 11, and is sprayed by the spraying means 1b. The cooler 18 is a type of heat exchanger, and heats the refrigerant mist mixed in the refrigerant vapor generated in the evaporator 1 with the warm refrigerant from the condenser 9 to promote its vaporization. The temperature of the refrigerant refluxed to 1 is lowered.

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 reflux 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. Make up.
The filter 4 is useful for preventing dust or rust in the absorbent solution from clogging the filler pipe in the rectifier 6 and causing a deterioration in function.

A pipe 7a connecting the absorber 2 and the rectifier 6;
The heat exchanger 12 provided in the middle of the regenerator 3b
The high-temperature concentrated liquid in the pipe 7a coming out of the absorber 2 is cooled by exchanging heat with the dilute liquid in the pipe 7 coming out of the absorber 2, and then fed to the absorber 2 for dispersion. On the other hand, the dilute solution preliminarily heated in the heat exchanger 12 is fed 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 the opening # 3, 4 of the first four-way valve V1, and the other end (the outlet end, the opening) is the opening # 3, 4 of the second four-way valve V2. (See FIGS. 2 and 3).
The indoor unit 15 is provided in a room that performs cooling and heating, and is provided with a fan 10 for blowing cool air or warm air (both are common) and an outlet (not shown). The sensible heat exchanger 14 is placed outdoors, and the fan 19 forcibly exchanges heat with the outside air.

Note that the subscript T with a subscript in the figure is a temperature sensor,
The suffix L represents a liquid level sensor, the suffix PS represents a pressure sensor, and the suffix V represents an on-off valve or a flow control valve.

During the heating operation by the heat pump, as shown in FIG. 2, the first and second four-way valves V1 and V2 are connected to their respective # 1 and # 4 openings, and # 2 and # 3
Switching control is performed to a position where the opening communicates. Thereby, the pipeline 2a warmed in the absorber 2 and the condenser 9
The indoor cooling water is guided to the pipeline 3a of the indoor unit 15 to heat the room.

Next, during the heating operation by this heat pump, if the outside air temperature becomes extremely low, the sensible heat exchanger 1
It becomes difficult to pump heat from the outside air through the heating device 4, and the heating capacity is reduced. Under such an outside air temperature condition, the heat pump cycle operation is stopped, the steam generated in the regenerator 3 is circulated between the condenser 9 and the heat generated by the burner 7 and the heat generated by the burner 7 is efficiently passed through the pipe 2a. The temperature of the cooling water is increased by an open flame heating operation that is conducted to the cooling water in the interior, thereby improving the heating capacity.

For this purpose, in the embodiment shown in FIG. 1, a recirculation passage 9a for bypassing between the condenser 9 and the regenerator 3 (or the rectifier 6) and an on-off valve 17 are provided. When the outside air temperature is low and the heating capacity is insufficient, first the condenser 9
The line 9b leading to the evaporator 1 and the lines 7a and 7b for the dilute and concentrated liquids between the absorber 2 and the regenerator 3 are shut off to stop the heat pump cycle, and the on-off valve 17 is opened for regeneration. The steam generated in the vessel 3 is returned to the condenser 9.

As described above, the switching control to the direct fire heating operation for improving the heating capacity is performed by providing a temperature sensor (T14) at an appropriate place inside and outside the room (for example, near the sensible heat exchanger 14). When the sensed temperature falls below a predetermined value, it can be automatically controlled by a controller that switches the valve. Whether the outside air temperature has dropped below the predetermined value can also be determined based on the magnitude of the heating load. The calculation of the heating load is described in Japanese Patent Application No. Hei 8-94 filed earlier by the present applicant.
No. 714, which is hereby incorporated by reference.

Further, during the cooling operation of the absorption type air conditioner such as the present invention, as shown in FIG. 3, the first and second four-way valves V1 and V2 are connected to the respective # 1 and # 3 openings. The switching control is performed so that the openings # 2 and # 4 communicate with each other. Thereby, the cold water in the pipe la cooled in the evaporator 1 is guided to the pipe 3a of the indoor unit 15 to cool the room. That is, during the cooling operation, the cold water cooled by the refrigerant of the evaporator 1 is guided to the indoor unit 15, and the blower fan 10 blows cool air into the room.

In the heating operation by the heat pump, even if the outside air temperature is equal to or higher than the predetermined value, the heat pump cycle operation cannot be performed, for example, when the set temperature of the heater is lowered and the heating load suddenly decreases. It may be. That is, in the heat pump cycle, the circulation of the refrigerant or the solution is secured by the pressure difference between the pressure of the condenser 9 on the high pressure side and the pressure of the evaporator 1 and the absorber 2 on the low pressure side, but the set temperature is lowered. When the heating load suddenly decreases, the amount of the diluent supplied to the regenerator 3 suddenly decreases, and therefore, the pressure of the condenser 9 and the pressure difference also decrease, making it difficult or impossible to continue the heat pump cycle operation. It may be.

In order to prepare for such a situation, a pressure sensor PS9 for detecting the pressure in the condenser 9 is provided, and when the pressure in the condenser 9 falls below the reference value, each switching valve is switched. The heat pump cycle may be switched to direct heat. Further, an evaporator pressure detector PS1 for detecting the pressure in the evaporator 1 is further provided, and when the output difference between the two pressure sensors, that is, the differential pressure is reduced to a reference value or less, the mode may be switched to direct heating. Good.

Further, since the condenser pressure is a function of the outside air temperature and the indoor unit set temperature, the condenser pressure is represented by a combination of the outside air temperature and the indoor unit set temperature, and the operating point determined by the combination is a predetermined range. It is also possible to generate a switching output when the heat pump cycle deviates from the heat pump cycle and switch to the direct heating. Regarding such a switching method, the applicant's earlier patent application (November 1996
(Filed on March 29), which is described in detail in “Absorption type cooling and heating device”, the description of which is referred to, and detailed description is omitted.

[0028]

According to the present invention, the flow paths of the refrigerant and the absorbent solution are the same in both the cooling operation and the heat pump operation, and the refrigerant and the absorbent solution flow paths are switched according to the switching between the cooling / heating operation modes. There is no need to switch, just switch the flow path of cooling water and cold water by a pair of four-way valve,
A configuration is greatly simplified, and a cooling and heating device suitable as a small-sized cooling and heating device for home use or the like is provided. Also, cooling /
When the mode of the heating operation is switched, a step of separating the refrigerant and the absorbent is not required, so that there is an advantage that the operation can be promptly shifted to the high efficiency operation.

Furthermore, during normal heating, a high-efficiency heating operation using a heat pump cycle can be performed, and at the same time, the outside air temperature drops extremely, making it difficult to pump up heat. The load suddenly decreases and the pressure of the high-pressure system such as the condenser decreases.
When the difference between the pressure of the high-pressure system such as the condenser and the pressure of the low-pressure system such as the evaporator may drop below the reference value, or the combination of the outside air temperature and the heating load is out of the planned range In such a case as well, by circulating the cooling steam between the condenser and the regenerator, it is possible to easily and quickly switch to the direct flame heating operation and maintain a desired heating temperature.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a cooling and heating device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of a cooling and heating device according to an embodiment of the present invention and a state of a piping system and a four-way valve during a cooling operation.

FIG. 3 is a diagram illustrating a state of a piping system and a four-way valve during a heating operation of the cooling and heating device according to the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Evaporator, 1a ... Pipe for cold water, 2 ... Absorber, 2
a: cooling water pipe 3: regenerator, 4: filter, 6
... rectifier, 7 ... burner, 9 ... condenser, 9a ... circulation passage 10 ... fan, 14 ... sensible heat exchanger, 15 ... indoor unit

Claims (4)

[Claims] 1. An evaporator for containing a refrigerant, an absorber for containing a solution containing an absorbent that absorbs refrigerant vapor generated in the evaporator to generate absorption heat, and heats a part of the solution. A regenerator that extracts refrigerant vapor to recover the absorbent concentration in the solution, a condenser that condenses the extracted refrigerant vapor and supplies the evaporator to the evaporator, A first pipe in which cold water passing through the evaporator is cooled by the refrigerant in the evaporator; and a cooling water passing through the first pipe and the solution in the absorber and the condenser. A second pipe line that is heated by refrigerant vapor in the inside, an indoor unit for blowing air for cooling and heating into the room, and a second unit that is disposed in the indoor unit and selectively passes one of the cold water and the cooling water. 3 pipes, one of the cooling water and the cold water, and the outside air. A sensible heat exchanger for performing heat exchange, a fourth pipe disposed in the sensible heat exchanger and selectively passing the other of the cold water and the cooling water, and one end of each of the first and second pipes A first four-way valve having one end of each of the third and fourth conduits connected to an opening thereof; the other end of each of the first and second conduits; and each of the third and fourth conduits A second four-way valve having the other end connected to the opening thereof, wherein the first and second four-way valves are arranged such that the first and second conduits are respectively the third and the fourth pipes in the cooling operation mode. An absorption-type cooling and heating device which is connected to four pipelines and is controlled to be switched so that the first and second pipelines are respectively connected to the fourth and third pipelines in the heating operation mode. 2. A recirculation path fluidly connecting the condenser and the regenerator, wherein during the heating operation, refrigerant vapor generated from the regenerator passes from the condenser via the recirculation path to the regenerator. The absorption-type cooling and heating apparatus according to claim 1, wherein the apparatus is configured to shift to a direct-fired heating operation by switching so as to circulate. 3. The outside air temperature during the heating operation is equal to or lower than a first predetermined value, the pressure value of the condenser is equal to or lower than a second predetermined value, and the differential pressure between the pressure of the condenser and the pressure of the evaporator is equal to a third predetermined value. In the following, when at least one of the conditions that the operating point determined by the combination of the outside air humidity and the indoor unit set temperature is out of the predetermined range is satisfied, the apparatus further includes means for opening the return path and circulating the refrigerant vapor. The absorption-type cooling and heating device according to claim 2, wherein: 4. The apparatus according to claim 2, wherein a means for separating an absorbent solution mixed into the refrigerant vapor generated in the regenerator is interposed between the regenerator and the condenser. The absorption type air conditioner according to the above.