JPH06281288A - Absorption type refrigerator using waste heat - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve start-up characteristics in an absorption refrigerator having a high-temperature regenerator that uses exhaust heat as a heat source and a high-temperature regenerator that burns fuel directly as a heat source. [Structure] A high temperature regenerator (34A) that uses exhaust heat as a heat source and a high temperature regenerator (34B) that directly burns fuel as a heat source.
And the absorption medium is supplied in series to a high temperature regenerator (34A) that uses exhaust heat as a heat source and a high temperature regenerator (34B) that directly burns fuel to serve as a heat source to form a refrigeration cycle, Detecting means (5) for detecting temperature or pressure in a high temperature regenerator (34A) that is directly burned to serve as a heat source.
0, 51) are provided, and the temperature or pressure of the high temperature regenerator (34B) that directly burns the fuel and serves as the heat source is set to a predetermined value or higher in the high temperature regenerator (34A) that directly burns the fuel and serves as the heat source. A control device (60) for shutting off or limiting the heat input when the temperature becomes low is provided. [Effect] According to the present invention, it is possible to obtain an absorption heat type refrigerator utilizing exhaust heat, which has excellent start-up characteristics and cost performance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption refrigerator utilizing waste heat.

[0002]

2. Description of the Related Art In the prior art, an absorption chiller driven by two heat sources is generally controlled by prohibiting simultaneous 100% input of the two heat sources. Note that, for example, Japanese Patent Laid-Open No. 3-25262 can be cited as a related example of this type.

[0003]

The maximum capacity of the above-mentioned conventional refrigerating machine is always 100% or less, whereas the absorption refrigerating machine itself has two built-in high temperature regenerators, so that the absorption medium held therein increases. However, it took a long time to heat and concentrate the solution, resulting in poor responsiveness such as poor ability to start up, and there was a problem in usability.

Further, since the heat source for directly burning the backup fuel is used only when there is no exhaust heat, the operating rate is low and the cost performance of the absorption refrigerator is low.

It is an object of the present invention to provide an absorption refrigerating machine utilizing exhaust heat which enhances the utilization of the backup heat source of the dual heat source driving absorption refrigerating machine and improves the starting characteristics.

[0006]

SUMMARY OF THE INVENTION The above object is to provide an exhaust heat absorption type refrigerating machine in which a high temperature regenerator, a low temperature regenerator, a condenser, an evaporator, and a solution heat exchanger are connected by piping, and the exhaust heat is used as a heat source. And a high temperature regenerator that directly burns fuel as a heat source, and a refrigeration cycle, a high temperature regenerator that uses an absorption medium as a heat source and a high temperature regenerator that directly burns fuel as a heat source. Is provided in series to form a refrigeration cycle, a temperature or pressure detecting means is provided in a high temperature regenerator that directly burns the fuel to be a heat source, and a high temperature regenerator that directly burns the fuel to be a heat source is This is achieved by providing control means for cutting off or limiting the heat input when the temperature or pressure of the high temperature regenerator, which directly burns the fuel and serves as a heat source, exceeds a predetermined value.

[0007]

[Function] When the chilled water outlet temperature is high at the time of starting the refrigerator, the heat input from the exhaust heat and the heat source for directly burning the fuel is rated 2
00%, transiently overheated and the capacity increased,
The chilled water outlet temperature of the refrigerator sharply drops, the direct combustion of the fuel is stopped below a predetermined temperature, and the operating state of only the exhaust heat source is entered. Here, as the operating conditions of the refrigerator,
When the temperature of the cooling water at startup is high, when the heat source that directly burns the fuel and 200% of the exhaust heat is input, the temperature conditions and pressure conditions move to higher temperatures and higher pressures, and the concentration of the absorption medium proceeds and the pressure also increases. There is a possibility that the temperature will rise and it will not be in a favorable condition for the continuous operation of the refrigerator. In such a case, if the temperature of the high temperature regenerator, which burns the fuel directly as a heat source, is higher than a predetermined value, or if the pressure is detected and is higher than the predetermined value, stop the heat source that directly burns the fuel. , The absorption refrigerator is protected.

[0008]

FIG. 1 shows an embodiment of the present invention. In the cooling operation cycle, the diluted solution diluted with the refrigerant (water) in the absorber 30 is converted into the low temperature solution heat exchanger 3 by the solution pump 31.
2. After passing through the high temperature solution heat exchanger 33 to a high temperature regenerator (hereinafter referred to as a waste heat heat source high temperature regenerator) 34A using exhaust heat as a heat source, after being heated there, the refrigerant is evaporated and concentrated,
Refrigerant vapor is generated at the same time as it flows down to a high temperature regenerator (hereinafter referred to as a direct-burning heat source high temperature regenerator) 34B that directly burns fuel as a heat source and is further heated and concentrated. Further, the dilute solution branched from the outlet of the low temperature solution heat exchanger 32 and sent to the low temperature regenerator 35 exchanges heat with the refrigerant vapor generated from the high temperature regenerators 34A and 34B to generate secondary refrigerant vapor. Concentrated. The concentrated solution concentrated in the exhaust heat heat source high temperature regenerator 34A and the direct heat source high temperature regenerator 34B passes through the high temperature solution heat exchanger 33 and the low temperature regenerator 35 together with the solution concentrated in the low temperature solution heat exchanger 32. , These solution heat exchangers 32,
Sensible heat is applied to the dilute solution at 33 and then dispersed in the absorber 30. On the other hand, each of the refrigerant vapors generated in the exhaust heat source high temperature regenerator 34A, the direct heat source high temperature regenerator 34B and the low temperature regenerator 35 is condensed in the low temperature regenerator 35 and the condenser 36,
It becomes a refrigerant liquid and flows down into the evaporator 37. Here, the refrigerant is sprayed into the evaporator by the refrigerant spray pump 38,
Evaporation heat is obtained from the cold water in the cold water pipe 41 to evaporate, and is absorbed by the spray concentrated solution in the absorber via the vapor passage that connects the evaporator 37 and the absorber 30. The heat of condensation of the refrigerant generated in the absorber 30 is removed by the cooling water circulating in the cooling water pipe 40. The cooling water passes through the absorber 30 and circulates through the above-described condenser 36 to remove the heat of condensation of the refrigerant vapor generated in the low-temperature regenerator 35, and then discharges the heat of condensation to the outside in a cooling tower (not shown). , Cooled. In the cooling cycle described above, heat is input to both the high temperature regenerators of the exhaust heat heat source high temperature regenerator 34A and the direct heating heat source high temperature regenerator 34B. Basically a similar cycle is formed.

FIG. 2 shows a case where the refrigeration cycle described above is shown on a Duhring diagram of an aqueous solution of lithium bromide, where the horizontal axis is temperature, the vertical axis is pressure, and the solution concentration is the parameter.
Cycle A shows the case where the exhaust heat source or the direct heating source is driven alone, and the cycle B is the case where both the heat sources are driven. In the case of driving with both heat sources, the heating amount is 2 compared with the case of driving with a single heat source.
Since it doubles, high temperature regenerators 34A, 34B, condenser 35
The cycle temperature and pressure on the high-pressure side of (1) increase, approaching the crystal line of the aqueous solution of lithium bromide, and the pressure (high temperature regenerator) also exceeds atmospheric pressure. Therefore, it is not preferable for the refrigerator to continuously operate in such a state, and heat input limitation is necessary. In the present invention, as shown in FIG. 1, a signal from the temperature detector 50 or the pressure detector 51 arranged in the direct-fired heat source high temperature regenerator 34B is supplied to the controller 6 as a signal.
0, and when the temperature or pressure reaches a predetermined value, the controller 61 operates the valve 61 to operate the direct heat source high temperature regenerator 34.
Block or limit the heat input to B. Therefore, it is possible to avoid the operation under the high temperature and high pressure conditions described above.

Generally, the capacity of the cooling tower corresponds to the operation of a single heat source, so when the temperature of the cooling water is high, 2
When the heat input is 00%, the pressure detector 51 operates to limit the heat input, and during low cooling water temperature operation, the capacity of the cooling tower increases, so the pressure is held low, and the temperature detector 50 operates to input heat. Restrictions are enforced. As described above, the refrigerator can make the maximum activation of its own heat input source and shorten the startup time.

Although the embodiments of the present invention have been described above, it is obvious that the embodiments of the present invention can be similarly applied to any other absorption refrigeration cycle other than the above refrigeration cycle. .

[0012]

According to the present invention, it is possible to obtain a waste heat absorption type refrigerating machine which is easy to use and excellent in cost performance.

[0013]

[Brief description of drawings]

FIG. 1 is a flow sheet showing an example of the present invention.

FIG. 2 is a graph illustrating a cycle in the example of the present invention.

[Explanation of symbols]

30 ... Absorber, 31 ... Solution pump, 32 ... Low-temperature solution heat exchanger, 33 ... High-temperature solution heat exchanger, 34A ... High-temperature regenerator using exhaust heat as a heat source, 34B ... Directly burn fuel to use as a heat source High temperature regenerator, 35 ... Low temperature regenerator, 36 ... Condenser, 4
0 ... Cold water piping, 41 ... Cooling water piping, 50 ... Temperature detector,
51 ... Pressure detector, 60 ... Control device 61 ... Valve

Front Page Continuation (72) Kenji Machizawa, Inventor Kenjimachi, Tsuchiura City, Ibaraki Prefecture, 603 Kuchitari, Tsuchiura Plant, Ltd. Incorporated (72) Inventor Yasushi Osawa 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph Telephone Co., Ltd. (72) Inventor Isamu Sudo 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Co., Ltd. (72) Inventor Masayoshi Nakao 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation

Claims (1)

[Claims] 1. An exhaust heat utilization absorption refrigerating machine comprising a high temperature regenerator, a low temperature regenerator, a condenser, an evaporator and a solution heat exchanger connected in a pipe, wherein a high temperature regenerator using exhaust heat as a heat source and a fuel are used. A refrigeration cycle is configured by providing a high-temperature regenerator that burns directly as a heat source and supplies the absorption medium in series to a high-temperature regenerator that uses exhaust heat as a heat source and a high-temperature regenerator that burns fuel directly as a heat source. A high temperature regenerator that burns the fuel directly as a heat source is provided with detection means for detecting temperature or pressure, and a high temperature regenerator that burns the fuel directly as a heat source burns the fuel directly to form a heat source. An exhaust heat utilization absorption refrigerator, which is provided with control means for cutting off or limiting heat input when the temperature or pressure of the high temperature regenerator exceeds a predetermined value.