JPS618596A - Method of heat-exchanging for continuously heating circulating gas - Google Patents

Abstract

PURPOSE:To lower as far as possible both the amount of a heating gas that will mingle with a gas to be heated and the amount of the gas to be heated that must be supplied, by introducing the gas to be heated that has remained in a heat exchanger into another heat exchanger from which the remained heating gas has been evacuated after the completion of the heat accumulation thereby recovering said gas to be heated, and purifying said gas to be heated followed by introducing into a circulating circuit. CONSTITUTION:A gas 1e to be heated flows into a heat exchager is wherein it is heated, and at the same time a heating gas 1i flows into a heat exchanger 2a wherein the heat is accumulated. On the other hand, in the heat exchanger 3a, the remaining heating gas has been evacuated, the gas 1f to be heated that has remained in a heat exchanger 4a flows into the heat exchanger 3a and then into a tank 2b that has been evacuated. Thus, the heating gas remained in the heat exchanger 3a wherein heat accumulation has been completed is accompanied by a gas to be heated that has remained in the heat exchanger 4a and flows into a tank 2b. Therefore, the heating gas can be prevented from mixing into the circulating circuit for the gas to be heated. Further, the gas 1g to be heated is fed from a tank 1b that is filled with the gas to be heated that has remained in the heat exchanger 2a into an apparatus 1b for purifying a gas to be heated wherein the impurities are removed and the gas flows into a tank 3b.

Description

Detailed Description of the Invention (Technical Field) The present invention utilizes a plurality of regenerative heat exchangers by alternately switching between them to reduce the amount of heated gas circulating between the heat exchanger and the heat engine. The present invention relates to a heat exchange method for continuous heating of circulating gas that continuously heats by storing heat by heated gas, and is particularly designed to suppress mutual mixing of heated gas and heated gas as much as possible.

(Prior Art) Conventionally, in power generation devices such as closed cycle MHD power generation devices and closed cycle gas turbine power generation devices, or in upper chemical plants, the heated gas circulating between the heating device and the heat engine is Storing the heat of the heated gas,
A heat exchange device is required that can continuously heat the gas to be heated above the temperature at which a metal bulkhead heat exchanger can normally be used, and can also minimize mixing of the heated gas into the gas to be heated. It is said that For example, metal bulkhead heat exchangers are usually used for heat exchange between gases at temperatures below about 1000°C, but for high-temperature heat exchange over 1000°C, traditional metal heat exchangers have been used in the steel industry. Regenerative heat exchangers that use ceramics as a heat storage material have been used, such as in air heaters for hot stoves.

In such a regenerative heat exchanger J5, the heat stored in the heat storage body is generally reduced by passing the heated gas through the heat storage body after the heat storage body is heated in the process in which the heated gas passes through the heat storage body. The heat of the gas is radiated to the heated gas, and the heated gas is heated. However, one regenerative heat exchanger cannot store heat in the heat storage body and radiate heat to the heated gas at the same time, so in order to continuously heat the heated gas, multiple heat storage units are required. It is necessary to store heat in the heat storage body and radiate heat to the heated gas by alternately switching the type heat exchanger.

(Problem) However, in the gas-to-gas heat exchange device as described above, since the heated gas and the heated gas alternately pass through the same heat storage body, it is necessary to switch the heat exchanger from heat storage to heat radiation. In some cases, the heated gas remaining in the heat exchanger mixes into the heated gas, and when the heat exchanger is switched from heat radiation to heat storage, the heated gas remaining in the heat exchanger mixes with the heated gas. Mixed into heated gas. Therefore, when the circulating gas to be heated is heated by the heat exchanger switching method as described above, a large amount of the heated gas gets mixed into the circulation path of the gas to be heated, so the amount of the mixed gas can be controlled. If it is necessary to suppress heat as much as possible, when switching the heat exchanger from heat storage to heat radiation, first evacuate the heated gas remaining in the heat exchanger before introducing the heated gas into the heat exchanger. was previously proposed. However, by using only such conventional measures, heated gas remaining in the heat exchanger without being completely exhausted, or outside air leaking into the heat exchanger during vacuum evacuation, remains in the circulation path of the heated gas. It will end up being mixed in. Furthermore, if the heated gas is discharged outside after passing through the heat exchanger, such as combustion gas,
When switching the heat exchanger from heat radiation to heat storage, the heated gas mixed in with the heated gas is directly discharged to the outside along with the heated gas, so the same amount of dark heated gas as is discharged is removed. Seventh, there is the disadvantage that a new supply has to be made into the circuit every time the heat exchanger is changed over, resulting in significant losses if the gas to be heated is expensive.

(Objective) The object of the present invention is to eliminate the above-mentioned conventional drawbacks, to continuously heat the circulating gas to be heated using the heat possessed by the heated gas, and furthermore, to It is an object of the present invention to provide a heat exchange method for continuous heating of circulating gas, which can minimize the amount of mixed heating gas and the amount of heated gas that requires replenishment.

(Structure of the Invention) In other words, the heat exchange method for continuous heating of circulating gas of the present invention, when switching a plurality of regenerative heat exchangers from heat radiation to heat storage,
The heated gas remaining in the heat exchanger is recovered by introducing it into another heat exchanger that has evacuated the heated gas remaining inside after the heat storage is completed, and then the recovered heated gas is recovered. After the gas is purified by a purification device, it is introduced into the circulation path of the gas to be heated.

Therefore, according to the heat exchange method for continuous heating of circulating gas of the present invention, by using a plurality of regenerative heat exchangers alternately (switchingly), the circulating heated gas can be continuously heated using the heat possessed by the heated gas. In addition, when one or more heat exchangers switch from heat radiation to heat storage, the heated gas remaining in each heat exchanger is recovered and introduced into the circulation path. By doing so, the amount of heated gas that needs to be replenished can be minimized.Furthermore, when recovering heated gas from one or more heat exchangers that have finished dissipating heat, the internal By introducing and passing the heated gas whose heat has been radiated into one or more other heat exchangers which have evacuated the heated gas remaining in the latter heat exchanger, the vacuum side 1 is introduced into the latter heat exchanger. The heated gas and outside air that remain after the air can be discharged out of the heated gas circulation path together with the recovered heated gas, and the recovered heated gas is supplied to a purification device for purification. If it is later introduced into the circulation path, it becomes possible to significantly reduce the amount of heated gas introduced into the heated gas in the circulation path.

(Example) The present invention will be described in detail below with reference to the drawings.

As shown in FIGS. 1 to 12, a heat exchanger FA device for continuous heating of circulating gas that implements the method of the present invention includes, for example, regenerative heat exchangers 1a, 2a, 3a, 4a, a tank for filling gas to be heated, etc. lb, 2b, 3b, heated gas transfer pump 1c
, 2c, consists of a heated gas evacuation pump 3G and a heated gas purification device 1d.

Figures 1 to 12 show the flow of heated gas and heated gas in each of the 12 steps that constitute one cycle in which heat storage and heat radiation are alternately switched in the four heat exchangers described above. The embodiments are shown in sequence.

According to FIG. 1, in the first stage, the heat exchanger 1a is in the circulation path of the heated gas, and the heated gas 1e is in the heat exchanger 1.
It flows into a and is heated by heat radiation from the internal heat storage body,
The heated gas 2e is heated to a higher temperature.

At the same time, in the heat exchanger 2a, the heated gas 11 at a higher temperature flows in, thereby heating the internal heat storage body and storing heat, and conversely, the heated gas 11 is cooled to become the heated gas 21, and the heat exchanger 2a is heated. It flows out from the vessel 2a.

On the other hand, in the heat exchanger 3a, the heat storage by the heated gas and the subsequent evacuation of the residual heated gas have been completed, and the heated gas remaining inside the heat exchanger 4a after the heat dissipation is completed. , the residual heated gas 1f flows into the heat exchanger 3a, and after once filling the heat exchanger 3a, or immediately passes through the heat storage body inside the heat exchanger 3a, the residual heated gas 2f flows into the heat exchanger 3a. The heat flows into the evacuated tank 2b until the pressure in the heat exchangers 3a, 4a and the tank 2b becomes equal. Through the above process, most of the heated gas remaining in the heat exchanger 3a after heat storage and the outside air that leaked into the heat exchanger 3a during evacuation remain in the heat exchanger 4a. The IC heated gas flows into the tank 2b along with the IC heated gas. Therefore, it is possible to prevent the heated gas and outside air from entering the circulation path of the heated gas. Furthermore, in this first stage, 1 g of heated gas remaining in the heat exchanger 2a is sucked out by the pump 1C from the tank 1b filled with the heated gas, the pressure is increased, and the gas is heated as 2 g of heated gas. The heated gas 3q, which has been sent to the heated gas purification device 1d and has become highly purified by removing impurity components therein, flows into the tank 31).

Next, in the second stage shown in FIG. Heat exchanger 2a
In this case, heat storage is carried out by heating the heat storage unit with heated gas. On the other hand, the heat exchanger 3a filled with the heated gas remaining in the heat exchanger 4a is filled with 1 h of high-purity heated gas from the tank 3b until the pressure of the heated gas in the circulation path is reached. is filled. During that time, the heated gas 1f remaining in the heat exchanger 4a is sucked out by the pump 2C and transferred to the tank 2b as heated gas 2f, and the heated gas 1f remaining in the heat exchanger 4a is finally removed. Collection will be carried out. Note that the process of transferring the heated gas filling the tank 1b to the tank 3b is performed subsequent to the seventh stage.

Next, in the third stage shown in FIG. 3, following the first and second stages, the heat exchanger 1a is located in the circulation path of the heated gas and radiates heat to the heated gas. Furthermore, in the heat exchanger 4a where the recovery of the remaining heated gas has been completed, heating of the heat storage body by the heated gas has started. On the other hand, in the heat exchanger 2a after the heating of the heat storage body by the heated gas is completed, the heated gas 1j remaining inside the heat exchanger 2a
is evacuated by the pump 3C, and the heated gas 2J discharged from the pump 3C is discharged to the outside. Also, tank 2b
The heated gas 1g filled in the tank 1b is sucked out to the pump 1C together with the heated gas 1g filled in the tank 1b, is pressurized, and is sent to the heated gas purifier 1d as heated gas 2g. The heated gas 3Q, which has been made highly pure by removing the impurity components contained therein, flows into the tank 3b.

Next, in the fourth stage shown in FIG. Dissipate heat to. Furthermore, through the process up to this point,
At the beginning of the first stage, the gas remaining in the heat exchanger 4a [the gas to be heated is recovered via the tank 2b and the tank 3b,
The purified gas is introduced into the heating gas circulation path via the heat exchanger 3a. Therefore, in the fourth stage, heat exchanger 1a is transferred to heat exchanger 3a, heat exchanger 2a
is connected to heat exchanger 4a, heat exchanger 3a is connected to heat exchanger 2a, heat exchanger 4a is connected to heat exchanger 1a, and tank 1b is connected to tank 2b.
In addition, exactly the same process as the first stage is performed with tank 2b being replaced by tank 1b.

Next, in the fifth stage shown in FIG.
a to heat exchanger 3a, heat exchanger 2a to heat exchanger 4a,
The heat exchanger 3a is connected to the heat exchanger 2a, the heat exchanger 4a is connected to the heat exchanger 1a, the tank 1b is connected to the tank 2b, and the tank 2
Exactly the same process as the second stage is carried out, with each tank 1b being replaced by tank 1b.

Next, in the sixth stage shown in FIG.
a to heat exchanger 3a, heat exchanger 2a to heat exchanger 4a,
Heat exchanger 3a is replaced with heat exchanger 2a, heat exchanger 4a is replaced with heat exchanger 1a, tank 1b is replaced with tank 2b, tank 2b is replaced with tank 1b, and the third stage is completely replaced. The same process takes place.

Next, in the seventh stage shown in FIG.
a to heat exchanger 2a, heat exchanger 2a to heat exchanger 1a,
Exactly the same process as the first stage is performed with heat exchanger 3a being replaced by heat exchanger 4a, and heat exchanger 4a being replaced by heat exchanger 3a.

Next, in the eighth stage shown in FIG.
a to heat exchanger 2a, heat exchanger 2a to heat exchanger 1a,
With the heat exchanger 3a replaced with the heat exchanger 4a and the heat exchanger 4a replaced with the heat exchanger 3a, the same process as in the second stage is performed.

Next, in the ninth stage shown in FIG.
a to heat exchanger 2a, heat exchanger 2a to heat exchanger 1a,
Exactly the same process as the third stage is performed with heat exchanger 3a being replaced by heat exchanger 4a, and heat exchanger 4a being replaced by heat exchanger 3a.

Next, in the 10th step shown in FIG.
, the first
Exactly the same process takes place.

Next, in the 11th stage shown in FIG.
, with the heat exchanger 3a replaced by the heat exchanger 1a, the heat exchanger 4a replaced by the heat exchanger 2a, the tank 1b replaced by the tank 2b, and the tank 2b replaced by the tank 1b, the second
Stages and money (the same process takes place.

Next, in the twelfth stage shown in FIG. 12, heat exchanger 1a is replaced by heat exchanger 4a, heat exchanger 2a is replaced by heat exchanger 3a
, with the heat exchanger 3a replaced by the heat exchanger 1a, the heat exchanger 4a replaced by the heat exchanger 28, the tank 1b replaced by the tank 2b, and the tank 2b replaced by the tank 1b, the third
Exactly the same process takes place.

After going through each of the above 12 steps, the heat exchange device according to the present invention returns to the first step again, and one cycle in which heat storage and heat radiation are alternately switched in the four regenerative heat exchangers is completed. finish. In other words, in any of the 12 steps, some heat exchanger is always in the circulation path of the heated gas and heats the heated gas by heat radiation. It will be heated continuously.

Further, the heated gas remaining in each heat exchanger after heating the heated gas by heat radiation is stored in tanks Ib and 2b.

3b, the gas is recovered and purified, and is introduced into the heating gas circulation path again through each heat exchanger.

Furthermore, most of the heated gas remaining in each heat exchanger after the heating of the heated gas has finished storing heat in the heat storage body is discharged to the outside by the pump 3C, and the remainder is recovered from each heat exchanger. Since the heated gas flows into the heated gas purifier 1d together with the heated gas and is removed from the heated gas, the amount of heated gas mixed into the heated gas circulation path is extremely small.

Although the present invention has been described in detail with reference to the embodiments described above, the present invention is not limited to the above-mentioned embodiments, and particularly the number of regenerative heat exchangers, pumps, tanks, etc. used, Of course, various modifications may be made to the procedure for recovering the heated gas remaining in the vessel without departing from the gist of the present invention.

Effect) As is clear from the above explanation, according to the present invention, the heated gas is heated to a temperature that the heat storage body can withstand by passing the heated gas alternately through a plurality of regenerative heat exchangers. It is possible to continuously heat the gas to be heated with heat, and also to recover the gas to be heated remaining in the heat exchanger when one or more heat exchangers switch from heat radiation to heat storage. By guiding the heated gas into the circulation path, the number of replenishment chambers for the necessary heated gas can be minimized. Furthermore, when one or more heat exchangers switch from heat storage to heat radiation, most of the heated gas remaining inside the heat exchanger can be pumped out to the outside. Regarding the heated gas, the heated gas flows out of the heated gas circulation path together with the heated gas recovered from the other heat exchangers that have finished heat radiation, so the heated gas The amount of heated gas mixed into the circulation path can be suppressed to an extremely low level.

[Brief explanation of drawings]

Figures 1 to 12 show a cycle of heat storage and heat radiation in four heat exchangers.
FIG. 3 is a structural layout diagram sequentially showing examples of flow patterns of heated gas and heated gas in each step; FIG. Ia, 2a, 3a, 4a... Regenerative heat exchanger 1b, 2
b, 3b... Heated gas filling tank IC, 2C...
・Heated gas transfer pump 3C... Heated gas evacuation pump 1d... Heated gas purification device

Claims (1)

[Claims] A heated gas that stores the heat of the heated gas supplied to the heat exchanger and continuously circulates between the heat exchanger and the heat engine by alternately switching and using a plurality of regenerative heat exchangers. When continuously heating the heated gas, the heated gas remaining in at least one heat exchanger after the heated gas has been heated by the stored heat is removed. introducing the heated gas into the evacuated at least one heat exchanger and recovering it;
A heat exchange method for continuous heating of a circulating gas, characterized in that the recovered heated gas is supplied to a purification device and purified, and then introduced into a circulation path for the heated gas.