JPH06323687A - Refrigerator and operation thereof - Google Patents

Abstract

PURPOSE:To provide a refrigerator which can be operated efficiently by utilizing a low temperature waste heat. CONSTITUTION:A refrigerator has a solution circulation path formed of at least absorbers 23 and 24, solution pumps 28 and 38 and a reproducer 6, a refrigerant gas circulation path formed of at least a condenser 12, an expanding device 45, and evaporators 46 and 57, a high pressure refrigerant gas passage 11 leading from the reproducer 6 to the condenser 12, and a low pressure refrigerant gas passage 37 leading from the evaporators 46 and 57 to the absorbers 23 and 24, and compressors 49 and 50 are provided in the low pressure refrigerant gas passage 37. The evaporator is formed of a low temperature evaporator 46 and a high temperature evaporator 57. These two evaporator 46 and 57 have means 52 and 53 respectively to switch the refrigerant circulation circuit and the low pressure refrigerant gas passage, and also a means to circulate refrigerant between the evaporators through the compressor 49. In addition, the abosorber has at least two or more abosorbers, one a high pressure side absorber 34 and the other a low pressure side absorber 23, and these two absorbers are connected to a compressing means of the compressors 49 and 50 correspondingly.

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. Figure 4
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, it 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 a degree. 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 three major problems. The first problem is that the performance on the absorption side is poor. That is, although it is waste heat, since it has a finite energy, the performance of the absorption refrigeration cycle is also important. As can be seen from FIG. 6, low-temperature waste heat cannot be used.

The second 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 third problem is that part of the absorbent in the solution mixes into the condenser side from the regenerator. 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 a refrigerator having a compressor, the absorber has two or more absorbers of at least a high pressure side absorber and a low pressure side absorber, and the compressor has at least two stages of a high pressure side compression stage and a low pressure side compression stage. And a refrigerant gas passage connecting the low pressure side compression stage and the low pressure side absorber and connecting the high pressure side compression stage and the high pressure side absorber.

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 extending from the evaporator to a low-pressure refrigerant gas passage extending from the absorber to the absorber, wherein the evaporator has a low-temperature evaporator and a high-temperature evaporator. And a means for switching the low-temperature refrigerant and the high-temperature evaporator between the refrigerant circulation path and the low-pressure refrigerant gas passage, respectively,
And means for circulating between both evaporators through a compressor.

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
4) It is a case where it can be made to flow to (105). In addition, in FIG. 2, there are two low temperature side condensers (104) and (105), and the refrigerant gas discharged from the low temperature side compressor also has a valve (1
06) to the auxiliary condenser side.

When this low temperature condenser is used, the cold water in the cold water tank (107) is (108) → (10) as the cooling water.
9) → (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 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, 22: 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, 105: low temperature side condenser , 107: Cold water tank

Claims (5)

[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. 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 absorber has at least a high-pressure side absorber and a low-pressure side absorber. One or more absorbers, the compressor has at least two or more compression stages of a high-pressure side compression stage and a low-pressure side compression stage, and connects the low-pressure side compression stage and the low-pressure side absorber to the high-pressure side. A refrigerating machine having a refrigerant gas passage connecting a compression stage and a high-pressure side absorber. 2. 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, and the low temperature evaporator and the high temperature evaporator have means for switching between the refrigerant circulation path and the low pressure refrigerant gas passage, and means for circulating between both evaporators through a compressor. A refrigerator characterized in that. 3. The operation method for operating the refrigerator according to claim 2 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. 4. 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 low-temperature side condenser has means for switching to be cooled by a fluid having a temperature lower than that of a fluid for cooling the high-temperature side condenser, and means for switching a refrigerant flow to the condenser and the auxiliary condenser. A refrigerator characterized by. 5. The compressor according to claim 1, wherein the compressor has a lubricating oil passage, and the lubricating oil flowing through the lubricating system and the absorbent in the solution circulation passage are the same substance. Refrigerator.