JPH09250837A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectually utilize even a relatively low temperature heating fluid and ensure stable operation even with a heating source where the amount of waste treat is varied by constructing a freezer such that a regenerator has two or more regenerators of a high pressure side one and a low pressure side one, and the heating fluid of the regenerator heats each regenerator. SOLUTION: High temperature water is supplied to a waste heat recovery apparatus 2 with a pump 3, and heat is recovered from waste gas, etc., supplied from a nozzle 4. The waste gas is cooled and discharged from a piping 5 to the outside. Heated warm water is parallely sent to a high pressure side regenerator 7 and a low pressure side regenerator 8 through branch pipes 6, 6', and the solution is heated in the respective regenerators to vaporize the refrigerant. Vapor is produced in the high pressure side regenerator 7, and the remaining weak solution absorbs the vapor in a high pressure side absorber 14. However, refrigerant gas absorbed by the high pressure side absorber 14 is the sum total of vapor produced in the low pressure side regenerator 8 and refrigerant gas sent from a compressor high pressure stage.

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.

As this practical absorption / compression hybrid refrigerator, a refrigeration cycle refrigerator shown in the i (enthalpy) -ξ (concentration) diagram of FIG. 4 is applied for a patent (Japanese Patent Application No. 3-45832). Have been proposed in. That is, in the regenerator process indicated by 101 → 102 in the figure, the refrigerant vapor is generated and becomes a weak solution. After that, the pressure is reduced in the low-pressure side absorber, the refrigerant gas is absorbed inside the absorber, and the concentration changes as in 103 → 104 to form an intermediate concentration liquid. Then, this solution is sent to the high-pressure side absorber by the pump and further absorbs the refrigerant gas to change its concentration from 105 to 106 to become a strong solution.
After that, the pump again sends 106 → 101 to the regenerator.

In this refrigerating machine, the refrigerant vapor evaporated in the evaporator is compressed on the low pressure side of the compressor, a part of the refrigerant gas is sent to the low pressure side absorber 103 to 104, and the remaining gas is further Compressed in the high pressure stage of the compressor, the above 105 → 10
6 to the high-pressure side absorber. That is, this cycle is designed to improve performance by equipping the absorber with two or more absorbers operating at different pressures.

However, the above compression / absorption hybrid refrigerator has the following two major problems.
The first problem is that the inlet temperature of the heating fluid that heats the regenerator is high. That is, in FIG. 4, for example, in the case of an ammonia / water system, when the condensation temperature is 35 ° C. and the concentration width is 25%, the temperature of the heating fluid is 84 ° C., which is a considerably high temperature.

The second problem is that stable operation is difficult due to fluctuations in the amount of waste heat that is the heating source of the regenerator, and it is difficult to properly predict and set the refrigerator capacity.
That is, if the temperature condition is constant, the capacity of the absorption refrigerator is
Although it is determined by the heating amount of the regenerator, the waste heat amount fluctuates due to external conditions unrelated to the refrigerator, and does not necessarily match the heat amount required for the refrigerator. For example, when the amount of waste heat is smaller than the refrigerator capacity, the expected cold heat output cannot be obtained, while
If the amount of waste heat is excessive, the cold heat output will be equal to the capacity of the refrigerator, but the usable energy will be discarded without being sufficiently recovered.

There is also a difficulty in predicting the amount of waste heat and determining the refrigerator capacity. If the amount of waste heat is predicted to be small, the refrigerator capacity to be determined will be small, and sufficient heat recovery will not be possible. If the determined refrigerator capacity is smaller than the required refrigerator capacity, a shortage of auxiliary refrigerators will be added, but this is not actually necessary, but at least smaller ones are sufficient, and excess equipment is required. Becomes On the contrary, if a large amount of waste heat is predicted, the capacity of the refrigerator to be determined becomes large, but a cold heat output more than that corresponding to the actual amount of waste heat cannot be obtained. Further, when the determined refrigerator capacity is larger than the required refrigerator capacity, the auxiliary refrigerator is not necessary, but the actually obtained cold heat output may be less than the required amount.

[0008]

DISCLOSURE OF THE INVENTION The present invention has solved the above-mentioned problems, and can be effectively used even with a heating fluid having a relatively low temperature, and can be operated stably even with a heating source whose waste heat amount fluctuates. It is an object to provide a refrigerator that can be used.

[0009]

In order to solve the above-mentioned problems, the present invention has an absorber, a solution pump and a regenerator, a solution circulation path connecting them, a condenser, an expansion device and an evaporator. And a refrigerant path connecting them, 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 compressed to the low pressure refrigerant gas passage. Compressor, and the absorber has two or more absorbers of a high-pressure side absorber and a low-pressure side absorber, and the compressor has two or more compression stages of a high-pressure side compression stage and a low-pressure side compression stage. A refrigerator having a refrigerant gas passage connecting the low pressure side compression stage and the low pressure side absorber between the absorber and the compressor, and connecting the high pressure side compression stage and the high pressure side absorber together with the regenerator. Has two or more regenerators, a high-pressure side regenerator and a low-pressure side regenerator. There has been configured to heat the regenerator, respectively.

Further, in the refrigerator, it is preferable to provide a control device for adjusting the diversion ratio of the low pressure side compression stage outlet in accordance with the heating amount related physical quantity of the regenerator.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The compression / absorption type hybrid refrigerator of the present invention has the following effects by adopting the above configuration. (1) The operation of the refrigerator of the present invention will be described with reference to the enthalpy-concentration diagram of FIG. 2 and the Duhring diagram of FIG. FIG.
In FIG. 3, steam is generated by the high pressure side regenerator of 111 → 112, and the remaining weak solution (meaning a solution in which the refrigerant has evaporated to reduce the concentration) absorbs the steam by the high pressure side absorber of 113 → 114. , 114 to pump again to the regenerator 111.

However, the refrigerant gas absorbed in the high-pressure side absorber is the total flow rate of the vapor generated in the low-pressure side regenerator and the refrigerant gas sent from the compressor high-pressure stage. The steam generated in the low pressure side regenerator is performed under the temperature condition of 115 → 116 in the figure.
That is, the maximum temperature is about 66 ° C., which is 8 ° in the case of FIG.
It can be about 20 ° C lower than 4 ° C. This indicates that it can be used with low-temperature waste heat. The weak solution discharged from the low pressure side regenerator absorbs vapor in the low pressure side absorber 117 → 118 and is returned to 115 again by the pump.

The refrigerator of the present invention can be operated by controlling the load balance between the electric power and the waste heat according to the heat supplyable amount of the waste heat source. That is, the refrigerant path from the evaporator to the high-pressure side absorber via the low-pressure side compression stage uses the power from the high-pressure side compression stage and the waste heat passing through the low-pressure side absorber and the low-pressure side regenerator. There are two types, that is, those that mainly utilize the above, and the flow rate ratio of these can be adjusted at the outlet of the low pressure side compression stage.

For example, when the amount of waste heat is sufficient, it is possible to stop the high pressure side compression stage and send the entire amount of refrigerant to the low pressure side absorber to increase the utilization of waste heat and save power consumption. . Also, if there is an amount of waste heat required for the high-pressure side regenerator, the entire refrigerating capacity 1
Operation at 00% is possible. In the case of an intermediate amount of waste heat, by changing the ratio of the refrigerant flow rate due to waste heat energy and the refrigerant flow rate due to electric power, such as by increasing or decreasing the flow rate of the high pressure side compression stage, the refrigerator power can be used with the minimum required electric power. You can drive.

[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, and as the waste heat, for example, waste heat of a gas engine driven refrigerator or fuel cell waste gas which is normally discarded is used.

High-temperature water is supplied to this 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 is sent in parallel to the high-pressure side regenerator 7 and the low-pressure side regenerator 8 by the branches 6 and 6 ', and the solution is heated in each regenerator to evaporate the refrigerant.

The refrigerant vapor evaporated in the high pressure side regenerator 7 is discharged to the condenser 11 from the pipe 10 after the refrigerant purity is increased in the high pressure side dephlegmator 9. A solution in which the refrigerant has evaporated and its concentration has decreased (hereinafter referred to as a high pressure weak solution. A solution having a high refrigerant concentration on the high pressure side is a high pressure strong solution, and a solution having a high refrigerant concentration on the low pressure side is a low pressure strong solution, a refrigerant concentration. The solution with reduced pressure is referred to as a low pressure weak solution) from the pipes 12 and 13 to the high pressure side absorber 14
Is cooled by the heat transfer surface of the tube 16 by the cooling water flowing in from the pipe 15 to absorb the refrigerant vapor from the nozzle 17 to form a high-pressure strong solution. Then, it flows from the nozzle 18 to the high-pressure side generator by the pump 19 via the pipes 20 and 21 high-pressure side dephlegmator 9 and the pipe 21.

On the other hand, the vapor generated in the low-pressure side regenerator is discharged to the high-pressure side absorber via the pipe 23 through the nozzle 17 after contacting with the high-pressure weak solution after the refrigerant purity is increased in the low-pressure side dephlegmator 22. Be absorbed. In addition, the low pressure weak solution after evaporation of the refrigerant is
The cooling water flowing from the pipe 24 into the low pressure side absorber 25 is cooled by the cooling water flowing from the pipe 26 on the heat transfer surface of the tube 27 to absorb the refrigerant vapor from the pipe 28 to form a low pressure strong solution. Then, it flows from the nozzle 29 into the low pressure side generator from the pipe 32 through the pipe 31 and the low pressure side dephlegmator 22 by the pump 30. On the other hand, the hot water cooled by the regenerator is the nozzle 33,
It flows out from 34, merges at 35, and flows into the heat recovery device 2 from the pipe 36. The condensed water in the cooled waste gas is discharged to the outside from the pipe 37 via the waste water treatment device 38.

The cooling water heated in the absorber passes through the pipe 39, condenses the refrigerant in the condenser 11, passes through the pipe 40, is cooled by the radiator 41, and is pumped by the pump 42 into the pipe 4.
Low pressure side absorber 25, high pressure side absorber 14 again via 3
Sent to 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 25 via the pipe 51.
Further, the remaining refrigerant gas is compressed again in the high pressure side compression stage 50 and is discharged to the high pressure side absorber 14.

In this device, the compressors 49 and 50 are not operated during the daytime. That is, the valves 52, 52 'are opened and the valves 53, 53', 54 are closed. Therefore, the condensed refrigerant passes through 44 → 52 → pipe 55 → expansion valve 56, cools and evaporates the cold water in the high temperature evaporator 57, and sends it to the high pressure side absorber 14 through the valve 52 ′, and the waste heat alone produces the solution. Evaporate the refrigerant inside. As the solution pump, only 19 are operated, 30 is not operated. Cold water is sent to the high temperature evaporator 57, cooled, and the cooled cold water is stored in the cold water tank 60.

When there is no waste heat and cold heat is stored in the cold water tank 60, the cold water is used as cooling water to operate in the "compression mode". That is, the valves 52 ', 5
3 ', 54, 53 are closed and valve 61 is opened. Therefore, the high temperature side evaporator 57 is used as a condenser, and the condensed refrigerant liquid flows to the check valve 63 → expansion valve 64 → evaporator 46 → compressors 49, 50 → valve 61 → high temperature side evaporator / condenser 57. In the low temperature side evaporator 46, brine and ice are cooled.

In the energy saving mode, the bypass valve 65 is opened, the valves 67, 61 and 52 'are closed, and the water side valves 66, 66', 66 ", 67, 67 'and 67" are opened.
, The operation of the compressor is stopped, and the compressor is operated as a waste heat driven refrigerator by cooling with cold water. That is, the refrigerant is 10 → 11 →
Cool the brine and ice in a flow 46 of 44 → 53 → 45 → 46 → 65 → 17. Cold water is 60 → 66 → 15 → 2
The flow absorption refrigeration cycle is cooled in the order of 6 → 16, 27 → 39 → 11 → 40 → 67 → 60. A two-stage split-flow compressor is usually used as the compressor, but two compressors, a low-stage compressor and a high-stage compressor, may be used.

[0023]

According to the present invention, two or more regenerators are provided on the high pressure side and the low pressure side, and the heating fluid is passed through each of the regenerators, so that waste heat having a lower temperature can be effectively used as the heating fluid. Now available. In addition, by adjusting the diversion ratio between the low pressure side and the high pressure side of the compressor according to the heat supply amount of the waste heat source to the regenerator, it is possible to operate by controlling the load balance between electric power and waste heat. It is possible to maximize the use of waste heat energy and operate the refrigerator with the minimum required power.

[Brief description of drawings]

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

FIG. 2 is an enthalpy-concentration diagram.

FIG. 3 is a Duhring diagram.

FIG. 4 is an enthalpy-concentration diagram of a known absorption / compression hybrid refrigerator.

[Explanation of symbols]

1: Absorption / compression hybrid refrigerator, 2: Waste heat recovery device, 3, 19, 30, 42: Pump, 4: Waste heat nozzle,
5: discharge pipe, 6, 6 ': hot water branch pipe, 7: high pressure side regenerator, 8: low pressure side regenerator, 9: high pressure side dephlegmator, 11: condenser, 14: high pressure side absorber, 22: Low-pressure side dephlegmator, 25:
Low-pressure side absorber, 38: wastewater treatment device, 41: radiator, 4
5, 64: expansion device, 46: evaporator, 49: low pressure side compression stage, 50: high pressure side compression stage, 57: high temperature evaporator, 60: cold water tank, 63: check valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Georg Arefelt Day 8000 Germany 40 Munich 40 Josef Wrapsstrasse 3

Claims (2)

[Claims] 1. An absorber, a solution pump, and a regenerator are provided,
It has a solution circulation path connecting them, a condenser, an expansion device, and an evaporator, and a refrigerant path connecting them, a high-pressure refrigerant gas passage from the regenerator to the condenser, and an evaporator to the absorber. A low pressure refrigerant gas passage, having a compressor in the low pressure refrigerant gas passage, and the absorber has two or more absorbers of a high pressure side absorber and a low pressure side absorber, the compressor is It has two or more compression stages, 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 absorber and the compressor, thereby forming a high-pressure side compression stage and a high-pressure side absorber. In the refrigerator in which the refrigerant gas passages are connected to each other, the regenerator has two or more regenerators of a high pressure side regenerator and a low pressure side regenerator,
A refrigerator characterized in that the heating fluid of the regenerator is configured to heat each regenerator. 2. The refrigerating machine according to claim 1, wherein the refrigerating machine is provided with a control device for adjusting a diversion ratio of the low pressure side compression stage outlet in accordance with a heating quantity related physical quantity of the regenerator. Machine.