JP2687080B2 - Refrigerator and its operating method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator, and more particularly to a hybrid refrigerator combining an absorption type and a compression type.

[0002]

2. Description of the Related Art Recently, from the viewpoint of power shortage and global warming, it has been proposed to use a "waste heat driven absorption refrigerator" which is driven only by waste heat after taking out power or power. However, since it is not possible to cover the increasing cold demand with waste heat alone, it seems practical to use an absorption / compression hybrid refrigerator combined with late-night power with ample equipment.

4 to 6 are explanatory diagrams for explaining the concept of the hybrid refrigerator. In both cases, the energy "quantity" is defined as "water quantity", the energy "quality" is compared to the "head", and the refrigerator is driven by the "turbine" so that energy can be easily understood from both "quantity" and "quality". FIG. 3 is a conceptual explanatory diagram described as a “pump” of FIG. FIG.
Is the case of a compression refrigerator.

In this case, the driving force is the power of the water turbine (113) driven by the water level difference between the high level (111) and the water level (112) corresponding to the ambient temperature (usually electric power in a refrigerator). Drives a pump (114) to pump heat from a temperature level of, for example, -10 ° C to ambient temperature. As can be seen from the figure, the lower the pumping temperature level, the greater the power of the turbine (electric power in the case of a refrigerator), but pumping is possible even from a low water level.

FIG. 5 shows the case of a waste heat driven absorption refrigerator.
An absorption chiller is a chiller that obtains "cold heat" by sucking the refrigerant vapor in the evaporator with the absorption capacity of the solution. That is, since the ability of sucking the refrigerant vapor is determined by the evaporation pressure, the type and the concentration of the solution, when the refrigerant vapor is absorbed and the refrigerant concentration becomes high, the refrigerant vapor becomes saturated. Therefore, the regenerator heats the vapor of the refrigerant to evaporate it, and the condenser condenses it to dilute the refrigerant concentration, but the heating temperature in this case is affected by the condensing pressure, so it is necessary to raise it considerably. .

This concept will be described with reference to FIG. As described above, the ability to absorb the refrigerant vapor is obtained by the concentration difference (115), and this concentration difference, when given the ambient temperature (112), is the waste heat recovery temperature (113) and the pumping temperature (114).
For example, in the case of the figure, when the waste heat temperature is 80 ° C, a certain difference in concentration can be obtained. The pumping temperature is 5 ° C.
It is about. That is, when the waste heat temperature is low, the low temperature cannot be obtained as shown in FIG.

Therefore, the absorption type and compression type hybrid refrigerators as shown in FIG. 6 are effective. That is, as shown in the figure, a pump (116) driven by a small-capacity water turbine (115) pumps up from a low water level portion (117), and then a pump (119) for concentration difference drive (turbine (118) drive). ), The water is discharged to the environmental water level (120). In this case, the power of the water turbine (115) may be less than in the case of FIG. In the figure (11
5) and (116) are compression refrigerators, and (118) and (1
19) is conceptually similar to the absorption refrigerator.

[0008]

However, the above-mentioned compression / absorption type hybrid refrigerator has the following four major problems. The first problem is the abolition of use.
The amount of heat was small. In general absorption refrigerator,
The return solution from the regenerator is heating the solution from the absorber.
However, this method uses less waste heat. Second
The problem with is that the performance on the absorption side is poor. That is, although it is waste heat, since it has finite energy, absorption refrigeration cycle performance is also important. As can be seen from FIG. 6, low-temperature waste heat cannot be used.

The third problem is that it is difficult to use the waste heat in the daytime. That is, at night, the hybrid refrigerator can be operated with the midnight power and waste heat, but if it is operated in the daytime, there is a problem that the waste heat cannot be utilized because it does not serve as a power crisis countermeasure. The fourth problem is that some of the absorbent in the solution enters the condenser side from the regenerator, which deteriorates the performance.
Or adversely affecting the compressor lubrication system.
It can happen . The present invention has been made in view of the above points, and an object thereof is to provide a refrigerator that solves the above problems.

[0010]

In order to solve the above problems, according to the present invention, a solution circulation path including at least an absorber, a solution pump, and a regenerator, and at least a condenser,
A refrigerant circulation path including an expansion device and an evaporator, a high-pressure refrigerant gas passage extending from the regenerator to the condenser, and a low-pressure refrigerant gas passage extending from the evaporator to the absorber, and the low-pressure refrigerant gas passage is compressed. in the refrigerator having the machine, or the absorber
The solution was heated with a regenerator and the solution was discharged from the regenerator.
A heat recovery heat exchanger that directly exchanges heat with the heating fluid is installed.
Introduce the solution heated by the heat exchanger into the regenerator.
It is configured as follows. In the above, heat exchange for heat recovery
The solution heated by the exchanger is heated by the regenerator and converted into steam.
It is preferable to provide a means for further heating the solution after generation.

Further, according to the present invention, a solution circulation path including at least an absorber, a solution pump and a regenerator, a refrigerant circulation path including at least a condenser, an expansion device and an evaporator, and a regenerator to a condenser. In a refrigerator having a high-pressure refrigerant gas passage leading to a low-pressure refrigerant gas passage extending from an evaporator to an absorber, and having a compressor in the low-pressure refrigerant gas passage, wherein the evaporator serves as a low-temperature evaporator and a condenser. Also works
The low temperature evaporator and the high temperature evaporator each have means for switching the refrigerant circulation path and the low pressure refrigerant gas passage, and means for circulating the refrigerant between both evaporators through a compressor. It is a thing. This frozen
Day machine, hybrid mode, compression mode,
In the operation method to drive each in energy saving mode,
In the daytime mode, the operation of the compressor is stopped,
A high temperature evaporator is used as an evaporator and is cooled by a low temperature evaporator.
A hybrid that cools cold water at a higher temperature than the low temperature fluid
In the mode, the compressor and solution pump are operated.
A low temperature evaporator is used as the evaporator to cool the low temperature fluid.
In the compression mode, the compressor is operated.
A low temperature evaporator is used as the evaporator,
After cooling, use the cooled cold water as the cooling water for the condenser.
And the compressor is stopped when in the energy saving mode.
A low temperature evaporator is used as the evaporator,
It was cooled and cooled as condenser and absorber cooling water.
It can be operated to use cold water.

Further, according to the present invention, a solution circulation path including at least an absorber, a solution pump and a regenerator, a refrigerant circulation path including at least a condenser, an expansion device and an evaporator, and a regenerator to a condenser. In a refrigerator having a high-pressure refrigerant gas passage leading to a low-pressure refrigerant gas passage extending from an evaporator to an absorber and having a compressor in the low-pressure refrigerant gas passage. And a means for switching the low-temperature condenser to be cooled by a fluid having a temperature lower than that of the fluid for cooling the high-temperature condenser, and switching a refrigerant flow between the condenser and the auxiliary condenser. It has a means. In the refrigerator, the compressor preferably has a lubricating oil passage, and the lubricating oil flowing through the lubricating system and the absorbent in the solution circulation passage are preferably the same substance.

[0013]

In the present invention, since the refrigerator is configured as described above, it is possible to operate in the following four modes: daytime mode, hybrid mode, compression mode, and energy saving mode. In the daytime mode, the operation of the compressor is stopped, the high temperature evaporator is used as the evaporator, and the cold water having a higher temperature than the low temperature fluid cooled by the low temperature evaporator is cooled. In the hybrid mode, the compressor and the solution pump are operated, the low temperature evaporator is used as the evaporator, and the operation is for cooling the low temperature fluid.

In the compression mode, the compressor is operated, the low temperature evaporator is used as the evaporator, the low temperature fluid is cooled, and the cooled cold water is used as the cooling water of the condenser. is there. In the energy saving mode,
In this operation, the compressor is stopped, a low temperature evaporator is used as an evaporator, a low temperature fluid is cooled, and the cooled cold water is used as cooling water for a condenser and an absorber.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the accompanying drawings, but the present invention is not limited thereto. Example 1 FIG. 1 is a flow configuration diagram showing a refrigerator of the present invention. In FIG. 1, reference numeral 1 is a compression / absorption type hybrid refrigerator. That is, this refrigerator is usually a hybrid system of a waste heat driven absorption refrigerator and a night power driven compression refrigerator at night. Reference numeral 2 denotes a waste heat recovery device. As the waste heat, for example, waste heat of a gas engine driven refrigerator, fuel cell waste gas or the like which is normally discarded is used.

High-temperature water is supplied to the waste heat recovery device by a pump (3), and heat is recovered from waste gas supplied from a nozzle (4). The waste gas is cooled and discharged to the outside through the pipe (5). The heated hot water flows into the regenerator (6) to heat the solution and evaporate the refrigerant.
The solution in the regenerator (6) flows from the low temperature part (7) to the high temperature part (9) via the communication passage (8), and flows into hot water and a counter flow to generate refrigerant vapor. The evaporated refrigerant vapor is discharged from the pipe (11) to the condenser (12) via the rectifier (10).

The hot water cooled by the regenerator is passed through the pipe (13) and is passed through the heat recovery heat exchanger (14) to the strong solution pipe (1).
5) A strong solution (hereinafter, a dilute solution having a refrigerant concentration is referred to as a weak solution, a solution having a high refrigerant concentration is referred to as a strong solution, and a solution having an intermediate concentration is referred to as an intermediate solution) sent from 5) is heated. The heated strong solution is supplied to the regenerator through the pipe (16). On the other hand, the cooled hot water returns to the waste heat recovery device (2) from the nozzle (18) via the pipe (17). When the waste heat is waste gas, the latent heat of steam in the waste gas can also be recovered, but in that case, the condensed water is drained from the pipe (19).

On the other hand, the weak solution flows from the nozzle (20) through the sensible heat recovery device (21) from the pipe (22) into the low pressure side absorber (23), and the cooling water flowing from the pipe (24). The tube (25) is cooled by the heat transfer surface by
The refrigerant vapor from 6) is sucked into an intermediate solution. Then, it is sent from the nozzle (27) to the high pressure side absorber (34) by the pump (28) via the heat recovery device (29) and the pipe (33). In the heat recovery device (29), the exhaust pipe (3
The hot water sent from 0) is further cooled and joins the pipe (32) via the pipe (31).

In the high-pressure side absorber (34), the solution is piped (3
It is cooled by the cooling water sent from 5), the absorption capacity rises, the refrigerant vapor is absorbed from the pipe (37) and becomes a strong solution, and it is sent from the pipe (15) to the heat recovery device (14) by the pump (38). . The cooling water heated in the absorber (34) passes through the pipe (39), condenses the refrigerant in the condenser (12), is cooled through the pipe (40) in the radiator (41), and is pumped. By (42), it is sent again to the low pressure side absorber (23) and the high pressure side absorber (34) via the pipe (43). On the other hand, the condensed refrigerant is sent to the evaporator (46) via the pipe (44) and the expansion device (45). The refrigerant vapor evaporated in the evaporator is compressed in the low pressure side compression stage (49), and a part thereof is sent to the low pressure side absorber (23) via the pipe (26). Further, the remaining refrigerant gas is compressed again in the high pressure side compression stage (50), and the high pressure side absorber (3
4) is discharged.

In the daytime, this device is operated by compressors (49), (5)
0) is not driven. That is, the valves (52) and (52 ')
Is opened and valves (53), (53 ') and (54) are closed. Therefore, the condensed refrigerant is (44) → (52)
→ Pipe (55) → Expansion valve (56), high temperature evaporator (57) cools cold water to evaporate, and valve (52 ′)
As a result, the refrigerant in the solution is evaporated only by the waste heat sent to the high pressure side absorber (34). As the solution pump, only (38) is operated, and (28) is not operated. High temperature evaporator (5
Cold water is sent to 7), cooled, and the cooled cold water is stored in a cold water tank (60).

When there is no waste heat and cold water is stored in the cold water tank (60), this cold water is used as cooling water.
It is operated in "compression mode". That is, the valve (5
2 '), (53'), (54), (53) are closed,
The valve (61) is opened. Therefore, the high temperature side evaporator (57) is used as the condenser, and the condensed refrigerant liquid is the check valve (63) → expansion valve (64) → evaporator (46) → compressor (49), (50) → valve. (61) → Flows from the high temperature side evaporator / condenser (57) to the low temperature side evaporator (46),
Cool the brine and ice.

In the energy saving mode, the bypass valve (65) is opened and the valves (67), (61), (5) are opened.
2 ') is closed and water side valves (66), (66'), (6
6 ″), (67), (67 ′), (67 ″),
The compressor is stopped and it is operated as a waste heat driven refrigerator by cooling with cold water. That is, the refrigerant is (11) → (12) →
(44) → (53) → (45) → (46) → (65) →
Cool brine and ice with (37) and stream (46). Cold water is (60) → (66) → (35), (24) →
(36), (25) → (39) → (12) → (40) →
(67) → (60) The flow absorption refrigeration cycle is cooled.

Although a two-stage split-flow compressor is usually used as the compressor, two compressors, a low-stage compressor and a high-stage compressor, may be used. The lubricant used for the compressor is the same as the absorbent. When the refrigerant is HFC, esters, ethers, PAG and the like are used.

FIG. 2 shows the compressor outlet pipe (101).
The refrigerant gas from is switched by the valves (102) and (103), and the high temperature side condenser (12 ') or the low temperature side condenser ( 10
This is the case when it is allowed to flow to 5). In addition, in FIG. 2, an auxiliary condenser (104) is further provided as a low temperature side condenser.
Provided, refrigerant gas exiting the low pressure side compression stage also, the valve (10
6) to the auxiliary condenser (104) side.

When this low-temperature condenser is used, the cold water in the cold water tank (107) is ( 109 ) → ( 10
8 ) → (110) → (104) → (105) → (10
7) You can play it. In this case, the cold water is operated in the absorption cycle without operating the compressor, and
The cold water obtained in 6) is used.

[0026]

Since the compression / absorption hybrid refrigerator of the present invention has the above-mentioned structure, it has the following excellent effects. (1) The effect of the refrigerator of the present invention will be described with reference to FIG. Given the conventional hybrid refrigerator pumping temperature t _L0 and waste heat recovery temperature t _H0 , the refrigerator of the present invention has two pumping temperatures, a pumping temperature t _L2 higher than t _L0 and a pumping temperature t _L1 lower than t _L0 , They correspond to a high temperature waste heat recovery temperature t _H2 and a low temperature waste heat recovery temperature, respectively. That is, as can be seen from FIG. 1, when the pressure is low, the high-temperature waste heat is used, and when the pressure is high, the low-temperature waste heat is used. Therefore, as can be seen from FIG. 3, the waste heat, which was conventionally used only up to t _H0 , can be used up to t _H2 .

(2) In the refrigerator of the present invention, cold water can be produced only with waste heat during the daytime, and when there is no waste heat, low-temperature cold heat can be obtained with less electric power. (3) The refrigerator of the present invention can obtain low temperature cold heat without using a driving compressor. (4) Further, since the lubricating oil and the absorbent are made the same substance, even if the absorbent is mixed in the refrigerant system, there is little adverse effect.

[Brief description of the drawings]

FIG. 1 is a flow configuration diagram showing a refrigerator of the present invention.

FIG. 2 is a flow configuration diagram showing another refrigerator of the present invention.

FIG. 3 is a schematic diagram for explaining the effect of the refrigerator of the present invention.

FIG. 4 is a conceptual explanatory diagram of a compression refrigerator.

FIG. 5 is a conceptual explanatory view of a low temperature waste heat driven absorption refrigerator.

FIG. 6 is a conceptual explanatory diagram of a compression / absorption type hybrid refrigerator.

[Explanation of symbols]

1: Compression / absorption type hybrid refrigerator, 2: Waste heat recovery device, 3: Pump, 4: Waste gas nozzle, 5: Waste gas discharge pipe, 6: Regenerator, 7: Low temperature part, 8: Communication passage, 9: High temperature part, 10: rectifier, 11: refrigerant gas pipe, 12, 1
2 ': condenser, 13, 17, 30, 31: hot water pipe, 1
4: Heat exchanger, 15, 16: Strong solution pipe, 18: Nozzle, 19: Drain pipe, 20, 22: Weak solution pipe, 21:
Sensible heat recovery device, 23 : low pressure side absorber, 24, 35, 3
9, 40, 43: cooling water pipes, 25, 36: cooling water tubes, 26, 37, 51: refrigerant vapor pipes, 27, 33:
Intermediate solution pipe, 28: pump, 29: heat exchanger, 34:
High-pressure side absorber, 38: solution pump, 41: radiator, 4
2: Pump, 44, 55: Refrigerant piping, 45: Expansion device,
46: evaporator, 47: cooling fluid, 48: ice making / accumulating system, 49: low pressure side compression stage, 50: high pressure side compression stage, 5
2, 52 ', 53, 53', 54, 61, 65, 66,
66 ', 66 ", 67, 67', 67": valve, 57: high temperature side evaporator, 58, 59, 60: cold water piping, 63: check valve, 64: expansion valve, 104 : auxiliary condenser, 105:
Low temperature side condenser, 107: cold water tank

Claims (6)

(57) [Claims] 1. A solution circulation path including at least an absorber, a solution pump, and a regenerator, a refrigerant circulation path including at least a condenser, an expansion device, and an evaporator, and a high-pressure refrigerant from the regenerator to the condenser. a gas passage, and a low-pressure refrigerant gas passage leading to the absorber from the evaporator, the refrigerator having a compressor to the low pressure refrigerant gas passage, from the absorber
Solution and the solution that was heated by the regenerator and heated from the regenerator
A heat recovery heat exchanger for directly exchanging heat with the fluid is provided.
It is designed to introduce the solution heated by the heat exchanger into the regenerator.
A refrigerator characterized by being made. 2. A solution heated by the heat recovery heat exchanger.
Is a solution that has been heated in the regenerator and has generated steam, and
The means for heating is provided, according to claim 1.
refrigerator. 3. A solution circulation path including at least an absorber, a solution pump, and a regenerator, a refrigerant circulation path including at least a condenser, an expansion device, and an evaporator, and a high-pressure refrigerant from the regenerator to the condenser. A refrigerator having a gas passage and a low-pressure refrigerant gas passage extending from the evaporator to the absorber, wherein the evaporator has a compressor in the low-pressure refrigerant gas passage,
It is composed of a low temperature evaporator and a high temperature evaporator which also functions as a condenser , and the low temperature evaporator and the high temperature evaporator have means for switching the refrigerant circulation path and the low pressure refrigerant gas passage respectively, and a compressor between both evaporators. A refrigerator having means for circulating the refrigerator. 4. The operation method for operating the refrigerator according to claim 3 in a daytime mode, a hybrid mode, a compression mode, and an energy saving mode, respectively. In the daytime mode, the operation of the compressor is stopped, and evaporation is performed. A high temperature evaporator is used as a condenser to cool cold water having a temperature higher than that of the low temperature fluid cooled in the low temperature evaporator.In the hybrid mode, the compressor and solution pump are operated and the low temperature evaporator is used as an evaporator. And cools the cryogenic fluid, and when in compression mode, the compressor is operated and a cryogenic evaporator is used as the evaporator to cool the cryogenic fluid and to cool it as the condenser cooling water. When cold water is used and further in the energy saving mode, the compressor is stopped, a low temperature evaporator is used as an evaporator, cools a low temperature fluid, and as cooling water for a condenser and an absorber, A method of operating a refrigerator, characterized in that the cooled cold water is used. 5. A solution circulation path including at least an absorber, a solution pump, and a regenerator, a refrigerant circulation path including at least a condenser, an expansion device, and an evaporator, and a high-pressure refrigerant from the regenerator to the condenser. In a refrigerator having a gas passage and a low-pressure refrigerant gas passage extending from an evaporator to an absorber, and having a compressor in the low-pressure refrigerant gas passage, the condenser includes a high-temperature side condenser and a low-temperature side condenser. , the cold-side condenser has means is switched so as to be cooled by the low temperature fluid than the fluid for cooling the high-temperature side condenser, and a high temperature
A refrigerator having means for switching a refrigerant flow between a side condenser and a low temperature side condenser. Wherein said compressor has a lubricating oil passage, according to claim 1, wherein the absorbent in the lubricating oil and the solution circulation path through the該潤lubricating system are the same substance, 3 or
The refrigerator according to 5 .