WO2012019314A1

WO2012019314A1 - Residual heat utilization system and method matched with energy level of cement kiln hood

Info

Publication number: WO2012019314A1
Application number: PCT/CN2010/001204
Authority: WO
Inventors: 韩涛; 李晨飞; 刑玉民; 史晓云; 肖衍党; 雷琰; 彭杰
Original assignee: 思安新能源股份有限公司
Priority date: 2010-08-09
Filing date: 2010-08-09
Publication date: 2012-02-16

Abstract

Disclosed is a residual heat utilization system (200A) matched with the energy level of a cement kiln hood, which includes a residual heat production device (210A), a first heat utilization device (220A) and a second heat utilization device (230A). A first temperature of a heat medium used by the first heat utilization device (220A) is higher than a second temperature of a heat medium used by the second heat utilization device (230A). The residual heat production device (210A) is provided with a first heat taking port (211A) which discharges the heat medium being of the first temperature. The first heat taking port (211A) is connected with the first heat utilization device (220A). The first heat utilization device (220A) is further provided with a first heat discharge port (221A) which sends out the heat medium being of the second temperature. The first heat discharge port (221A) is connected with the second heat utilization device (230A). A residual heat utilization method matched with the energy level of a cement kiln hood is also disclosed. The applications of the residual heat utilization system and method make the distribution of the heat medium be more reasonable and optimum, and make the efficiency of the whole system be improved.

Description

Thermal utilization system matching the energy level of cement kiln head 3⁄4 method

Technical field

The invention relates to the field of waste heat utilization, in particular to a waste heat utilization system and method for matching and utilizing energy levels of cement kiln heads. Background technique

In previous industrial production, such as cement production and steel metallurgy production, a large amount of heat generated in the production process was directly discharged into the surrounding environment and was not utilized. This not only causes energy waste, but also pollutes the surrounding environment. In order to utilize the waste heat generated in industrial production, some systems for utilizing waste heat have appeared in recent years. The waste heat utilization system will be described below in connection with cement production.

The cement industry is an energy and raw material intensive industry and is a major energy consumer. Cement production relies almost entirely on coal, electricity and mineral resources, and produces a large amount of waste heat. In order to comprehensively utilize this part of the waste heat resources, the waste heat is usually used in the new dry process cement production line, for example, using waste heat to generate electricity.

1 is a schematic illustration of a waste heat utilization system 100 of a prior art cement kiln. The system 100 includes a kiln head 101, a grate cooler 102, a residual heat utilization device 103, and a coal mill 104. One side of the kiln head 101 is connected to the cement manufacturing system. The cement manufacturing system is a system commonly used in the prior art and therefore will not be described in detail herein. The kiln head 101 is a fired cement clinker. The grate cooler 102 is connected to the kiln head 101. The fired clinker produced is sent to a grate cooler 102 for cooling and delivery. A blower is disposed below the grate cooler 102, and the blower blows air into the grate cooler 102 to cool the cement clinker and generate hot air from the grate cooler 102. A first heat extraction port 105, a second heat extraction port 105, and a third heat extraction port 106 are disposed above the grate cooler 102. The first heat take-up port 105 and the second heat take-up port 105 are located at the front end of the grate cooler 102, and the third heat take-up port 106 is located at the rear end of the grate cooler 102. The temperature of the first heat extraction port 105 and the second heat extraction port 105 near the kiln head 101 is relatively high, and the temperature of the third heat extraction port 106 away from the kiln head 101 is lower. The hot air discharged from the third heat extraction port 106 has a low temperature (about 150 ° C or so), and the use of the hot air of the lower temperature is difficult. Therefore, the hot air is directly removed by the first dust removing device 107 and then passes through the first An exhaust device (e.g., a chimney) 108 is exhausted. The first heat extraction port 105 and the second heat extraction port 105 have a higher temperature of the hot air discharged (large About 360 ° C to 420 ° C), this part of the hot air is the object of utilization of waste heat. From the second heat extraction port 105, the hot air discharged enters the settling chamber through the conveying pipe, removes most of the solid particles in the flue gas, and then supplies it to the waste heat utilization device 103 (such as an AQC waste heat boiler), and supplies the hot air to the waste heat utilization device 103. The waste heat utilization device 103 is used (for example, generating steam to generate electricity) and then discharged, and the discharged hot air is removed by the first dust removal device 107, and then discharged through the first exhaust device 108.

For the coal mill 104, since the hot air temperature used in the coal mill 104 cannot be too high, the temperature can be determined according to the moisture content of the coal powder, usually between about 200 ° C and 300 ° C, and from the first The temperature of the hot air flowing from the heat extraction port 105 to the coal mill 104 is about 300 ° C to 500 ° C. Because of the high temperature, the hot air cannot meet the needs of the coal mill 104, and the hot air is processed. . In general, the method of treatment is to provide a cold air plenum, and cold air is added to the hot air before the hot air enters the coal mill 104 to lower the hot air at a higher temperature to the temperature suitable for the coal mill 104. The cooled hot air passes through the second dust removing device 107 after being used by the coal mill 104, and is discharged by the second exhaust device 108.

In another prior art, the first heat extraction port 105 and the second heat extraction port 105 may be the same heat extraction port, and a part of the hot air taken out therefrom is supplied to the waste heat utilization device through the delivery pipe.

(For example, AQC waste heat boiler), another part is supplied to coal mill 104 through a conveying pipe.

For the above-mentioned cold air charging method, from the analysis of the entire thermal system, the incorporated cold medium (such as cold air) absorbs the heat of the system's heat medium, which increases the entropy production of the system, which undoubtedly reduces the system's waste heat utilization efficiency. When the waste heat utilization device is used to generate electricity, the power generation efficiency is also lowered.

The other processes in the prior art in which the coal mill takes the wind also have the above problems. In fact, the shield uses a heat medium to heat the cold medium, so that the quality of the part of the high temperature heat medium is reduced. From the perspective of the whole system, the incorporation of cold medium increases the entropy production of the system and reduces the heat utilization, thereby reducing the waste heat utilization efficiency of the entire system.

Therefore, there is a need for a new waste heat utilization system for the energy level matching of cement kiln heads and a waste heat utilization method to solve the above problems. Summary of the invention

In order to overcome the above deficiencies of the prior art, the present invention first provides a waste heat utilization system for matching and utilizing energy levels of a cement kiln, the waste heat utilization system including a waste heat generating device, a first heat utilization device, and a second heat utilization device. The first temperature of the heat medium utilized by the first heat utilization device is higher than the second temperature of the heat medium utilized by the second heat utilization device, the waste heat generating device Provided with a first heat extraction port, the first heat extraction port discharges a heat medium having the first temperature, and the first heat extraction port of the waste heat generating device is connected to the first heat utilization device, the first heat source The utilization device is further provided with a first heat exhaust port, and the first heat exhaust port discharges the heat medium having the second temperature, and the first heat exhaust port is connected to the second heat utilization device.

Further, the first heat utilization device is further provided with a second heat exhaust port and a heat inlet port, and the second heat exhaust port discharges the heat medium used by the first heat utilization device, the heat inlet port and the first heat receiving port Take the hot port connection.

Further, the second heat exhaust port and the heat inlet are respectively disposed at two ends of the first heat utilization device.

Further, the first heat exhaust port is disposed between the heat inlet port and the second heat exhaust port and is in a middle portion of the first heat utilization device.

Further, a backup duct is further disposed between the first heat take-up port and the second heat utilization device.

Further, the waste heat utilization system is connected to a cement kiln, the waste heat generating device is a grate cooler, the first heat utilization device is an AQC boiler, and the second maturation utilization device is a coal mill.

Further, a settling chamber is further disposed between the AQC boiler and the grate cooler.

Further, the first temperature is between 30 (TC to 500 °C, and the second temperature is between 200 °C and 300 °C.

Further, the AQC boiler is further provided with a second heat exhaust port and a heat inlet port, and the second heat exhaust port discharges the heat medium used by the AQC boiler, and the heat inlet port is connected to the first heat extraction port.

Further, the second heat exhaust port is connected to the dust removing device.

Further, the second heat exhaust port and the heat inlet are respectively disposed at two ends of the AQC boiler. Further, the first heat exhaust port is disposed between the heat inlet port and the second heat exhaust port, and is in the middle of the AQC boiler.

Further, a backup duct is further disposed between the first heat take-up port and the coal mill.

Further, the coal mill is connected to the standby pipe through a main pipe of a coal mill, and a cold air supply device is further disposed on the main pipe of the coal mill.

The invention further discloses a waste heat utilization method for energy level matching utilization of a cement kiln, the waste heat utilization method comprising the following steps:

a) obtaining a heat medium having a first temperature from a first heat take-up port of the waste heat generating device; b) passing the heat medium having the first temperature into the first heat utilization device;

c) obtaining a thermal medium having a second temperature from the first heat exhaust port of the first heat utilization device Quality, the second temperature is lower than the first temperature;

d) passing the heat medium having the second temperature to the second heat utilization device.

Further, the heat medium having the first temperature is passed into the first heat utilization device through the heat inlet provided on the first heat utilization device, and the first heat utilization device utilizes the heat medium to pass the first heat utilization. The second heat outlet provided on the device is discharged.

Further, the waste heat generating device is a grate cooler, the first heat utilization device is an AQC boiler, and the second heat utilization device is a coal mill.

Further, the heat medium having the first temperature is passed to the AQC boiler after passing through the settling chamber.

Further, the first temperature is between 300 ° C and 500 ° C, and the second temperature is between 200 ° C and

Between 300 ° C.

Further, the heat medium having the first temperature is introduced into the AQC boiler through a heat inlet provided on the AQC boiler, and the used heat medium of the AQC boiler is discharged through a second heat exhaust port disposed on the AQC boiler.

Further, the waste heat utilization method further comprises: passing the heat medium having the first temperature to the second heat utilization device by passing through the backup pipe and mixing with the heat medium having the second temperature.

The waste heat utilization system and the waste heat utilization method of the present invention enable the waste heat generated by the waste heat generating device to be fully utilized, thereby avoiding the practice of adding a large amount of cold medium to reduce the temperature of the heat medium before entering the second heat utilization device, so that the heat medium is distributed. More reasonable and optimized, the waste heat is fully utilized, which also improves the efficiency of the entire system.

A series of simplified forms of concepts are introduced in the Summary of the Invention, which will be described in further detail in the Detailed Description section. This Summary is not intended to be an attempt to define the key features and essential technical features of the claimed embodiments, and is not intended to limit the scope of protection of the claimed embodiments.

Advantages and features of the present invention are described in detail below with reference to the accompanying drawings. DRAWINGS

1 is a schematic diagram of a waste heat utilization system in the prior art;

2A is a block diagram of a waste heat utilization system in accordance with one embodiment of the present invention;

2B is a schematic diagram of a waste heat utilization system according to an embodiment of the present invention;

3 is a schematic diagram of a waste heat utilization system according to another embodiment of the present invention;

4 is a flow chart of a waste heat utilization method in accordance with one embodiment of the present invention. detailed description

In the following description, numerous specific details are set forth in the However, it will be apparent to those skilled in the art that the present invention may be practiced without one or more of these details. In other instances, some of the technical features well known in the art have not been described in order to avoid confusion with the present invention.

In order to thoroughly understand the present invention, a detailed structure will be set forth in the following description. It is apparent that the preferred embodiment is described in detail below, but the present invention may have other embodiments in addition to the detailed description.

Referring to Figure 2A, there is shown a block diagram of a waste heat utilization system 200A for use in cement kiln head level matching in accordance with one embodiment of the present invention. The waste heat utilization system 200A includes a waste heat generating device 210A, a first heat utilization device 220A, and a second heat utilization device 230A. The first temperature of the heat medium used by the first heat utilization device 220A is higher than the second heat utilization device 230A. a second temperature of the heat medium, the waste heat generating device 210A is provided with a first heat extraction port 211A, and the first heat extraction port 211A discharges the heat medium having the first temperature, the first take of the waste heat generating device 210A The hot port 211A is connected to the first heat utilization device 220A. The first heat utilization device 220A is further provided with a first heat exhaust port 221A, and the first heat exhaust port 221A discharges a heat medium having a second temperature, the first The heat exhaust port 221A is connected to the second heat utilization device 230A.

The first heat exhaust port 221A is disposed such that the second temperature matches the temperature of the heat medium usable by the second heat utilization device 230A.

Preferably, the first heat utilization device 220A is further provided with a second heat exhaust port 222A and a heat inlet port 223A. The second heat exhaust port 222A discharges the heat medium used by the first heat utilization device 220A, and the heat inlet port 223A is connected to the first heat extraction port 211A. The second heat exhaust port 222A and the heat inlet port 223A are respectively disposed at both ends of the first heat utilization device 220A.

Preferably, the first heat exhaust port 221A is disposed between the heat inlet port 223A and the second heat exhaust port 222A and is located in the middle of the first heat utilization device 220A.

Preferably, a backup duct 240A is further connected between the first heat exhaust port 221A and the second heat utilization device 230A. The role of the backup duct 240A will be described in detail below.

The embodiments of the present invention are further described in detail below in conjunction with the waste heat utilization system in a cement kiln.

Referring to Figure 2B, a schematic diagram of a waste heat utilization system 200 in accordance with one embodiment of the present invention. The arrows in the figure indicate the direction in which the heat medium flows. System 200 includes a grate cooler 210, a residual heat utilization device 220, and a coal mill 230. Wherein the grate cooler 210 is the above-mentioned waste heat generating device As an example, the waste heat utilization device 220 is an example of the above-described first heat utilization device, and the coal mill 230 is an example of the second heat utilization device. In the present embodiment, the quenching machine 210 is connected to the kiln head for generating a heat medium such as hot air, but the heat medium is not limited to hot air, and may be, for example, a hot liquid or the like. Cement manufacturing systems for kiln heads and connections to kiln heads are well known to those skilled in the art and will not be described herein.

An air blower is disposed below the grate cooler 210 to blow the heat medium in the grate cooler 210 in the form of hot air. A first heat extraction port 211 and a second heat extraction port 212 are disposed on the grate cooler 210. The first heat take-up port 211 is disposed at one end of the grate cooler 210 near the kiln head, and the second heat take-up port 212 is disposed at the end of the grate cooler 210 away from the kiln head. Since the first heat take-up port 211 is close to the kiln head, the temperature of the hot air discharged therein is relatively high, and the portion of the hot air has a first temperature, which may be, for example, about 300 ° C to 500. Between C, preferably between 360 ° C and 420 ° C, of course, the above temperature can also be exceeded. The temperature of the hot air discharged from the second heat extraction port 212 is relatively low (about 150 ° C), so that the portion of the heat medium is directly discharged by the first dust removing device 240 and then discharged through the first discharging device (e.g., smoke) 250. At this time, the system 200 further includes the first dust removing device 240 and the first discharging device 250.

For the heat medium (e.g., hot air) having the first temperature discharged from the first heat extraction port 211, it is first utilized by the heat inlet 223 of the waste heat utilization device 220 through the delivery pipe 221 to enter the waste heat utilization device 220. The heat utilization device 220 can be, for example, an AQC waste heat boiler. The heat medium can be heat exchanged in the waste heat utilization device 220 for utilization. For example, steam is generated by the heat medium to generate electricity. Further, a settling chamber 260 may be provided on the conveying pipe 221 to settle the impurities in the hot air. This type of dust removal can be carried out in a variety of ways, such as gravity dust removal, inertial force plus gravity dust removal, cyclone dust removal, and the like.

A first heat exhaust port 222 is provided on the waste heat utilization device 220. After the heat medium utilized by the waste heat utilization device 220, when the temperature thereof is lowered to a second temperature suitable for use by the coal mill 230 (for example, between 200 ° C and 300 ° C), the heat medium having the second temperature is taken from The first row of hot ports 222 are withdrawn to provide them to the coal mill 230. The extracted heat medium may be a part of the heat medium having the second temperature in the waste heat utilization device 220, and only the normal operation of the coal mill 230 is required. The remaining heat medium continues to be utilized in the waste heat utilization device 220, and finally the low temperature heat shield is discharged through the second heat exhaust port 224 of the waste heat utilization device 220. The extracted heat medium having the second temperature matches the temperature required by the coal mill 230. In order to protect the surrounding environment, the low-temperature heat medium discharged from the second heat-discharging port 224 of the waste heat utilization device 230 first enters the first dust-removing device 240 for dust removal, and is discharged through the first discharge device 250 after dust removal. The first dust removing device 240 can utilize various existing dust removing technologies, such as electric dust removing. The first heat exhaust port 222 of the appropriate waste heat utilization device 220 may be selected to achieve the purpose of obtaining the heat medium having the second temperature from the first heat exhaust port 222. For example, when the above-mentioned AQC waste heat boiler is used, in the case where the temperature of the first heat extraction port 211 is stable, different positions of the AQC waste heat boiler correspond to heat mediums of different temperatures, so that the temperature at different positions in the AQC boiler can be obtained first. Then, a first row of hot ports 222 is opened at a position between 200 ° C and 300 ° C. When the heat medium enters from the upper heat inlet 223 of the boiler and is discharged from the second heat exhaust port 224 at the lower portion of the boiler, that is, the heat inlet 223 and the second heat exhaust port 224 are respectively disposed at both ends of the boiler. The first heat exhaust port 222 is preferably disposed in the middle of the boiler. This makes it possible to obtain a preferred heat medium suitable for the second temperature of the coal mill 230.

The hot air entering the coal mill 230 is extracted from the waste heat utilization device 220, and is discharged after being used in the coal mill 230. The discharged heat medium is passed through the second dust removing device 240 and then discharged through the second discharging device 250 to the surrounding environment. It will be understood that the first dust removal device 240, the first discharge device 250 and the second dust removal device 240, and the second discharge device 250 are the same or similar.

Referring to Figure 3, there is shown a schematic diagram of a waste heat utilization system 300 in accordance with another embodiment of the present invention. The arrows in the figure indicate the direction in which the heat medium flows. The system 300 includes a grate cooler 310, a residual heat utilization device 320, a coal mill 330, a first dust removal device 340, a second dust removal device 340, a first discharge device 350, a second discharge device 350, and a settling chamber 360. A first heat extraction port 311 and a second heat extraction port 312 are disposed on the grate cooler 310. The first heat exhaust port 322, the second heat exhaust port 324, and the heat extraction port 323 are further disposed on the waste heat utilization device 320. The grate cooler 310 and the waste heat utilization device 320 are connected by a transfer duct 321 . These components of system 300 are identical or similar to corresponding components in system 200 described above and therefore will not be described again. The system 300 differs from the system 200 in that a backup duct 331 is connected between the first heat take-up port 311 of the grate cooler 310 and the coal mill 330. The coal mill 330 is connected to the backup pipe 331 through a coal mill main pipe 332. The alternate pipe 331 is normally closed. The heat medium is still flowing as described in connection with Figure 2. The advantage of providing the backup duct 331 is that the backup duct 331 can be utilized to continue the operation of the coal mill 330 when maintenance of the waste heat utilization device 320 is required. At this time, the standby pipe 331 operates in the same and similar manner as in the prior art. After the maintenance of the waste heat utilization device 320 is completed, it is only necessary to set the pipeline in the existing system as a backup pipe: it can be understood that the maintenance of the waste heat utilization device 320 is adopted. In the case of the backup pipe, a cold air supply device is provided before the heat medium enters the coal mill 330 and on the main pipe 332 of the coal mill 330, so that the temperature of the heat medium entering the coal mill 330 is suitable for the coal mill 330. usage of. Another benefit of the backup duct 331 is that when the first heat exhaust port 322 is from the waste heat utilization device 320 When the temperature of the extracted heat medium is low, the backup pipe 331 can be opened to supplement the heat medium into the coal mill 330.

Further, a valve device may be provided on the pipe connecting the above components. The above-mentioned pipes can be opened and closed by the valve device, so that each pipe can be easily repaired.

Referring to Figure 4, there is shown a flow diagram of a waste heat utilization method 400 in accordance with one embodiment of the present invention. The method 400 begins at step 410 where a heat medium having a first temperature is obtained from a first heat take-up port of a waste heat generating device, such as the grate cooler described above. The first temperature is higher, for example, may be between about 300 ° C and 500 ° C, preferably between 360 ° C and 420 ° C. The method 400 then proceeds to step 420 where the heat medium having the first temperature obtained by the first heat take-up port is passed to a first heat utilization device (such as the waste heat utilization device described above). Optionally, the heat medium having the first temperature is passed into the first heat utilization device through a heat inlet disposed on the first heat utilization device, and the first heat utilization device passes the first heat through the heat medium The second heat exhaust port provided on the device is discharged. Next, to step 430, a heat medium having a second temperature is taken from a first heat exhaust port of the first heat utilization device. The second temperature is lower, for example between 200 ° C and 300 ° C. See the above description for the setting of the first row of hot ports. Then, to step 440, the heat medium having the second temperature is passed to the second heat utilization device ' (such as the coal mill described above). The temperature of the heat medium that can be utilized by the second heat utilization device matches the second temperature and is lower than the first temperature.

The waste heat utilization system can be used in connection with a cement kiln. At this time, the waste heat generating device is a chiller, the first heat utilization device is an AQC boiler, and the second heat utilization device is a coal mill. Thus, the heat shield having the first temperature can be passed to the AQC boiler after passing through the settling chamber. The heat medium having the first temperature can be introduced into the AQC boiler through a heat inlet provided on the AQC boiler, and the utilized heat medium is discharged through the second heat exhaust port disposed on the AQC boiler. In such a case, the first temperature is between 300 ° C and 500 ° C and the second temperature is between 200 ° C and 300 ° C.

Further, the above method may further include the step of: passing the heat medium having the first temperature through the standby pipe and mixing with the heat medium having the second temperature to pass into the second heat utilization device. The spare pipe may be, for example, the spare pipe 331 described above. Thus, during normal operation, the heat medium can pass through the first heat utilization device and then enter the second heat utilization device. When the first heat utilization device needs to be inspected, the heat medium can be directly passed through the standby pipe to the second heat utilization device, and the cold air needs to be replenished. In addition, when the heat of the heat medium discharged from the first heat exhaust port of the first heat utilization device is insufficient, the standby pipe may be opened, so that the heat medium having the first temperature is passed. After passing through the backup pipe, it is mixed with the heat medium having the second temperature to pass into the second heat utilization device to increase the temperature of the heat medium entering the second heat utilization device.

The waste heat utilization system and the waste heat utilization method utilized by the energy level matching of the cement kiln head of the present invention can make full use of the waste heat generated by the waste heat generating device, and avoid adding a large amount of cold air to reduce the hot air before entering the second heat utilization device. The temperature method makes the distribution of the heat medium more reasonable and optimized, and makes full use of the waste heat, thus improving the efficiency of the whole system. Taking the above-mentioned cement kiln waste heat utilization system as an example, the waste heat utilization efficiency of the entire system is improved by about 5%.

The present invention has been described by the above-described embodiments, but it should be understood that the above-described embodiments are only for the purpose of illustration and description. Further, those skilled in the art can understand that the present invention is not limited to the above embodiments, and various modifications and changes can be made according to the teachings of the present invention. These modifications and modifications are all claimed in the present invention. Within the scope. The scope of the invention is defined by the appended claims and their equivalents.

Claims

Claim

A waste heat utilization system for matching the energy level of a cement kiln, the waste heat utilization system comprising a waste heat generating device, a first heat utilization device and a second heat utilization device, wherein the first heat utilization device utilizes a heat medium The first temperature is higher than the second temperature of the heat medium utilized by the second heat utilization device, the waste heat generating device is provided with a first heat extraction port, and the first heat extraction port is discharged with the first temperature The heat medium is characterized in that the first heat extraction port of the waste heat generating device is connected to the first heat utilization device, and the first heat utilization device is further provided with a first heat exhaust port, The first heat exhaust port discharges the heat medium having the second temperature, and the first heat exhaust port is connected to the second heat utilization device.

2. The waste heat utilization system according to claim 1, wherein the first heat utilization device is further provided with a second heat exhaust port and a heat inlet port, wherein: the second heat exhaust port is discharged The heat medium used by the first heat utilization device is connected to the first heat extraction port.

The waste heat utilization system according to claim 2, wherein the second heat exhaust port and the heat inlet port are respectively disposed at both ends of the first heat utilization device.

The waste heat utilization system according to claim 3, wherein the first heat exhaust port is disposed between the heat inlet port and the second heat exhaust port and is in the first heat utilization device Central.

The waste heat utilization system according to claim 1, wherein a backup duct is further provided between the first heat extraction port and the second heat utilization device.

6. The waste heat utilization system according to claim 1, wherein said waste heat utilization system is connected to a cement kiln, said waste heat generating device is a grate cooler, and said first heat utilization device is an AQC boiler. The second heat utilization device is a coal mill.

7. The waste heat utilization system according to claim 6, wherein a settling chamber is further provided between the AQC boiler and the grate cooler.

A waste heat utilization system according to claim 6, wherein said first temperature is between 300 ° C and 500 ° C and said second temperature is between 200 ° C and 300 ° C.

The waste heat utilization system according to claim 6, wherein the AQC boiler is further provided with a second heat exhaust port and a heat inlet port, and the second heat exhaust port is discharged from the AQC boiler. The heat medium is connected to the first heat extraction port.

10. The waste heat utilization system according to claim 9, wherein the second heat exhaust port is connected to the dust removing device.

The waste heat utilization system according to claim 9, wherein the second heat exhaust port and the heat inlet port are respectively disposed at both ends of the AQC boiler.

The waste heat utilization system according to claim 11, wherein the first heat exhaust port is disposed between the heat inlet port and the second heat exhaust port, and is in the middle of the AQC boiler .

A waste heat utilization system according to claim 6, wherein a backup duct is further provided between said first heat extraction port and said coal mill.

14. The waste heat utilization system according to claim 13, wherein the coal mill and the standby pipe are connected by a main pipe of a coal mill, and a cold air charging device is further disposed on the main pipe of the coal mill. .

15. A cement kiln head energy level - a residual heat utilization method for matching utilization, the waste heat utilization method comprising the following steps:

c) obtaining a heat medium having a second temperature from the first heat exhaust port of the first heat utilization device, the second temperature being lower than the first temperature;

d) passing the heat medium having the second temperature into the second heat utilization device.

The waste heat utilization method according to claim 15, wherein the heat medium having the first temperature is introduced into the first heat utilization device through a heat inlet provided on the first heat utilization device The heat medium utilized by the first heat utilization device is discharged through the second heat exhaust port disposed on the first heat utilization device.

The waste heat utilization method according to claim 15, wherein the waste heat generating device is a grate cooler, the first heat utilization device is an AQC boiler, and the second heat utilization device is a coal mill.

The waste heat utilization method according to claim 17, wherein the heat medium having the first temperature is passed to the AQC boiler after passing through the settling chamber.

A waste heat utilization method according to claim 17, wherein said first temperature is between 300 ° C and 500 ° C and said second temperature is between 200 ° C and 300 ° C.

The waste heat utilization method according to claim 17, wherein the heat medium having the first temperature is introduced into the AQC boiler through a heat inlet provided in the AQC boiler. mouth, , ,

The waste heat utilization method according to claim 15, wherein the waste heat utilization method further comprises: mixing the heat medium having the first temperature through the standby pipe and mixing the heat medium having the second temperature The second heat utilization device is introduced.