CN111637698B

CN111637698B - Drying device and method for continuously drying wood by using solar energy

Info

Publication number: CN111637698B
Application number: CN201910153981.6A
Authority: CN
Inventors: 何正斌; 伊松林; 钱京; 曲丽洁; 王振宇
Original assignee: Beijing Forestry University
Current assignee: Zhejiang Yilan Technology Co ltd
Priority date: 2019-03-01
Filing date: 2019-03-01
Publication date: 2022-02-15
Anticipated expiration: 2039-03-01
Also published as: CN111637698A

Abstract

The invention discloses a device and a method for continuously drying wood by utilizing solar energy, wherein the device comprises a solar drying kiln with auxiliary heat, and a heat storage system for storing redundant heat in the solar drying process of the wood and discharging high-temperature and high-humidity medium heat of the drying kiln, wherein the heat storage system is arranged at the outer side of the longitudinal side wall of the drying kiln, and meanwhile, an auxiliary heat source is also arranged in the device; the device is used for absorbing the redundant heat in the solar drying process of the wood and the heat of the medium discharged from the drying kiln and then drying the wood at night, accurately measuring the heat stored by the heat storage material in the heat storage system, accurately supplementing the using amount of an auxiliary heat source in the drying process at night, and realizing the continuous drying process of the wood. The device has simple structure, realizes the cooperative drying process of solar energy and auxiliary heat, accurately matches the use amount of the wood and the heat storage material, detects the energy consumption stored by the heat storage material, accurately controls the drying process, realizes the continuous drying of the solar energy, and has high quality of the dried wood and less drying defects.

Description

Drying device and method for continuously drying wood by using solar energy

Technical Field

The invention relates to a solar drying method with a heat storage system, in particular to a wood solar predrying method with the heat storage system.

Background

The wood drying is an essential link in the wood product processing process, and the energy consumption of the wood drying accounts for about 40-70% of the total energy consumption in the wood product processing process. The traditional conventional drying process adopts fossil energy, and has the problems of high energy consumption, serious pollution and the like. Solar energy is inexhaustible as a clean energy source and is used in the drying process of various biomasses such as food, wood and the like. However, the solar energy is intermittent and unstable, and cannot be used in rainy days and at night, so that the application process is severely limited. The phase-change heat storage material can store relatively more energy with smaller volume, and is widely used in the solar drying process.

For example: application number 201810047608.8 discloses a heat release system is stored up with inferior normal low temperature phase transition in greenhouse, this system adopts and greenhouse environment characteristic and crop demand assorted, the inferior normal low temperature phase change material that has different phase transition temperature, and use it in combination, the abundant collection of daytime surplus heat in the greenhouse has been realized, the storage, the gradient that needs the heat at night is supplied with, phase transition heat storage technique, inferior normal low temperature phase change material combination technique and solar energy utilization technique fuse organically, the problem such as the half night of system is released the heat and is not strong enough or release lag time overlength has been solved, reply bad weather condition that can be better, thereby guarantee the indoor suitable crop growing environment of greenhouse. Application number 201611154080.1 discloses a phase-change heat storage material applied to solar wood drying and a preparation method thereof, wherein the phase-change heat storage material is prepared from stearic acid and expanded graphite through mechanical mixing and a melting adsorption method. According to the solar phase-change heat storage material prepared by the method, stearic acid can be effectively filled in the pores of the expanded graphite, and the expanded graphite and the stearic acid are compounded without chemical change; the melting and solidification phase transition temperatures of the composite material are 52.74 ℃ and 53.70 ℃ respectively, and the melting and solidification phase transition latent heat is 169.90J/g and 166.10J/g respectively; compared with stearic acid, the stearic acid is slightly reduced, and the requirement of practical application is still met. The prepared composite phase-change heat storage material has good thermal cycle stability after 500 times and 1000 times of thermal cycle. Compared with stearic acid, the prepared composite phase-change heat storage material has the advantages that the heat storage and release time is respectively shortened by 39.74% and 45.09%, and the heat storage/release efficiency is effectively improved. The addition of expanded graphite ameliorates the problem of uneven heat release from stearic acid. Application number 201511024355.5 discloses an adopt solar heat storage device of honeycomb shape heat-retaining unit, this solar heat storage device can utilize solar energy heat accumulation, and energy-concerving and environment-protective adopts phase change heat storage material, compares traditional solar energy heat storage water tank, and its heat-retaining density is big, and the heat utilization time is long, can continuously produce hot water at night and when overcast and rainy weather. Granted patent 201511025153.2 discloses a solar phase-change heat storage wall and a ventilation system with the same, wherein the solar phase-change heat storage wall is formed by sequentially connecting a high-temperature phase-change layer, a medium-temperature phase-change layer and a low-temperature phase-change layer, the phase-change layers of which the phase-change temperatures are from high to low. The device can overcome the shortcoming of traditional thermal-arrest wall, has that the heat accumulation can the reinforce, and the function is various, and easy operation, and the advantage of the energy of not consuming can play aeration cooling and heating domestic water's effect in summer, can be used for heating in winter, has good application prospect. The granted patent 201520074347.0 discloses a phase-change heat-storage coupling solar heat-storage and supply system, which stores heat by using phase-change latent heat of a heat storage material, and has the advantages of low and constant heat storage temperature, low operation temperature of a heat-conducting working medium, high heat collection efficiency of a solar heat collector, and low heat loss of the solar heat collector and a pipeline; and the heat exchange energy storage device has large capacity, small volume, small occupied space and less heat dissipation loss. The granted patent 201220547210.9 discloses a phase change heat storage device and a solar heating system using the same. The phase-change heat storage device adopts the heat storage container with an independent unit structure, the heat storage capacity is high, the phase-change energy storage material does not corrode the heat exchanger, and the detection and the maintenance are convenient. The granted patent 200910243599.0 discloses a method for drying wood by using solar energy, the movable solar drying device of the invention has stable operation, the drying temperature can be kept constant, and continuous drying is realized; the drying energy consumption is obviously reduced, so that the drying cost is reduced, and the drying quality is better; the method has high solar energy conversion efficiency.

The existing invention can realize phase change heat storage of solar energy to a great extent, but the solar energy is directly absorbed for heat storage, the amount of stored heat cannot be accurately analyzed, the solar energy is not fully utilized, and the cooperative drying process of the solar energy and auxiliary heat cannot be realized. The invention not only can utilize and store solar energy, use the solar energy for drying wood, but also can obtain the total heat storage amount at any time, further accurately control the opening and closing of auxiliary heating, fully utilize the stored heat, and simultaneously store the heat in the high-temperature and high-humidity wet air which needs to be discharged outside the drying kiln in the drying process, thereby realizing energy conservation and emission reduction and utilizing the heat source to the maximum extent.

The invention recovers and utilizes the heat energy in the high-temperature and high-humidity waste gas generated when the solar energy is used for drying the wood, thereby not only reducing the humidity-discharging times in the solar energy drying process, but also recovering and utilizing the heat energy of the high-enthalpy water vapor, having higher heat efficiency and improving the solar energy drying efficiency.

Disclosure of Invention

The invention aims to solve the technical problems that the solar energy is intermittent and can not continuously provide energy for the drying process and the heat storage amount of a heat storage material can not be measured and the waste gas heat energy can not be recycled and continuously dried in the existing solar energy drying process, and provides a device for continuously drying wood by using solar energy and a method for continuously drying wood by using the device; the method accurately calculates the heat storage amount of the heat storage system, provides accurate guidance for the starting of the auxiliary heater at night or when the solar energy is insufficient, and saves the energy to the maximum extent; the invention adopts a method combining day continuous drying and night kiln-closing drying, eliminates the drying stress generated in the day drying of the wood, reduces the moisture content gradient, reduces the drying defects of wood cracking and the like, and improves the drying quality of the wood.

In order to achieve the object of the present invention, in one aspect, the present invention provides an apparatus for continuously drying wood by using solar energy, comprising a solar drying kiln, wherein the solar drying kiln is provided with an auxiliary heating assembly therein, and further comprising a heat storage system for storing excess solar heat in a wood drying process and heat of a high-temperature and high-humidity drying medium to be discharged out of the drying kiln, wherein the heat storage system comprises a heat storage tank and a plurality of heat storage pipes installed in the heat storage tank; the heat storage box is arranged on the outer side of the longitudinal or transverse side wall of the drying kiln, and a heat storage air door, a first heat storage fan set and a second heat storage fan set are arranged on the longitudinal or transverse side wall of the drying kiln and used for conveying the drying medium in the drying kiln into the heat storage box and transferring the heat carried by the drying medium to the heat storage system for storage.

The surplus solar heat is a heat source provided by solar energy except for the energy required by the wood drying process (for example, when the temperature is higher than 65 ℃, part of the solar energy is used for drying wood, and part of the solar energy is stored in a heat storage system); namely, the heat stored by the heat storage system is derived from solar energy and the high-temperature and high-humidity drying medium to be discharged out of the drying kiln.

Wherein the auxiliary heating component selects one or more of a heater, a steam pipe, a hot water pipe or a hot oil pipe.

In particular, the heat storage tank is arranged outside the longitudinal side wall of the solar drying kiln.

In particular, the solar drying kiln is selected from a top wind type solar drying kiln with an auxiliary heat source.

The phase-change heat storage materials are packaged in the heat storage pipes, and the phase-change heat absorption of the phase-change heat absorption materials is used for absorbing redundant solar heat in the drying process of the wood in the drying kiln and heat carried by high-temperature high-humidity drying media to be discharged out of the drying kiln or phase-change heat release to heat the wood in the drying kiln and dry the wood.

In particular, the phase-change heat-absorbing material is selected from one or more of paraffin, alkane or stearic acid, and is preferably paraffin.

Besides paraffin, stearic acid, polyethylene glycol or alkane, other substances known in the art for absorbing or releasing energy during phase change are suitable for use in the present invention.

The first heat storage fan set and the second heat storage fan set are embedded on the common side wall of the drying kiln and the heat storage box; and a heat storage air door is arranged on the side wall of each fan facing one side of the drying kiln, and the heat storage air door corresponds to the heat storage fan.

Particularly, the first heat storage fan set and the second heat storage fan set are opposite in rotation direction.

Particularly, the first heat storage fan set and the second heat storage fan set respectively comprise at least 2 fans, and the axis of each fan is perpendicular to the side wall.

Particularly, the first heat storage fan set and the second heat storage fan set are respectively arranged at the front end and the rear end of the side wall shared by the drying kiln and the heat storage box, and the fans of the first heat storage fan set and the second heat storage fan set are respectively arranged along the vertical direction of the drying kiln and are respectively positioned on the same straight line.

Particularly, the installation heights of the fans of the first heat storage fan set and the second heat storage fan set correspond to each other and are the same.

In particular, the system also comprises a detection system for measuring the temperature, the relative humidity and the moisture content of the wood in the drying kiln.

Wherein the detection system comprises: a hygrothermograph and a moisture content tester for wood.

Particularly, the hygrothermographs are used for measuring the temperature and the relative humidity of the drying medium in the drying kiln, are respectively positioned on the side walls of the drying kiln corresponding to the air inlet end and the air outlet end of the material pile, and the hygrothermographs on the inner wall of the same side are positioned on the vertical central line of the side walls of the drying kiln and are vertically arranged along the drying kiln; the wood moisture content tester is used for measuring the moisture content of the wood, is arranged at the upper part, the middle part and the lower part of the wood pile, and obtains the average moisture content of the wood by measuring the average value.

In another aspect, the present invention provides a method for continuously drying wood using the above apparatus for continuously drying wood using solar energy, comprising the steps of, in order:

1) measuring the usage amount of phase change heat storage material and heat storage pipe in the continuous wood drying device

1A) Calculating the dosage M of the phase change heat storage material of the heat storage system in the wood drying device according to the formula (1):

in the formula (1), M is the mass of a phase-change heat storage material in the heat storage system, kg, and H is the phase-change latent heat of the heat storage material, kJ/kg; t is t₁The average temperature of the drying kiln in the autumn (obtained by consulting weather data of the drying kiln in the autumn) is DEG C;

is driedAverage relative humidity of the drying kiln in autumn; t is t_mzThe highest temperature of a drying medium in the drying kiln is the temperature at which the drying treatment of the drying kiln is finished in a closed kiln at night;

the maximum relative humidity of the drying medium in the drying kiln is the maximum relative humidity of the drying medium in the drying kiln when the drying treatment of the drying kiln is finished in the closed kiln at night; l is the longitudinal length of the drying kiln, m; w is the transverse width of the drying kiln, m; h is the vertical height of the drying kiln, m; k is 1.2 to 2.0;

1B) calculating the using amount of the heat storage pipe according to the size of the heat storage pipe, packaging the phase change heat storage material in the heat storage pipe, and then installing the heat storage pipe in the heat storage tank;

2) solar drying process

Measuring the temperature and the relative humidity of the medium in the drying kiln beginning at 7:30-8:00 am, wherein:

2-1) when the temperature is lower than 45 ℃ (namely <45 ℃), starting an auxiliary heating component and drying a kiln circulating fan; closing the first heat storage fan set, the second heat storage fan set, the heat storage air door and the air inlet and outlet, performing solar energy and auxiliary heating drying, and heating the wood in the stacking and drying kiln;

2-2) when the temperature is higher than 45 deg.C (i.e. > 45 deg.C) and lower than 60 deg.C (i.e. <60 deg.C) with the drying process, wherein

2-2a) when the relative humidity is lower than 80% (namely less than 80%), starting an auxiliary heater and a circulating fan of the drying kiln; closing the first heat storage fan set, the second heat storage fan set, the heat storage air door and the air inlet and outlet, performing auxiliary heating, and performing solar energy and auxiliary heating drying;

2-2b) when the relative humidity is higher than 80% (namely more than or equal to 80%) and lower than 95% (namely less than 95%), closing a circulating fan and an air inlet and outlet of the drying kiln; opening the first and second heat storage fan sets and the heat storage air door, allowing the drying medium to flow into the heat storage box under the action of the heat storage fan sets to heat the phase-change heat storage material, allowing the phase-change heat storage material to start heat storage, and storing redundant heat into the heat storage system; wherein if the auxiliary heater is in an on state, the auxiliary heater is turned off; if the auxiliary heater is in the off state, the auxiliary heater does not need to be started;

2-2c) when the relative humidity is higher than 95% (namely more than or equal to 95%), closing the first heat storage fan set, the second heat storage fan set and the heat storage air door; starting a circulating fan and an air inlet and outlet of the drying kiln to carry out dehumidification treatment; removing the high-humidity medium in the drying kiln, introducing external fresh air into the drying kiln until the relative humidity in the drying kiln is reduced to 80 percent or the temperature in the drying kiln is lower than 45 ℃, closing the air inlet and outlet, and then starting a circulating fan and an auxiliary heater in the drying chamber;

2-3) when the temperature is higher than 60 ℃ (60 ℃ and lower than 65 ℃ (65 ℃), wherein

2-3a) when the relative humidity is lower than 80% (namely less than 80%), starting a circulating fan of the drying kiln; closing the air inlet and outlet, the first heat storage fan set, the second heat storage fan set and the heat storage air door, and drying the wood;

2-3b) when the relative humidity is higher than 80% (namely more than or equal to 80%) and lower than 95% (namely less than 95%), closing a circulating fan and an air inlet and outlet of the drying kiln; opening the first and second heat storage fan sets and the heat storage air door, allowing the drying medium to flow into the heat storage box under the action of the heat storage fan sets to heat the phase-change heat storage material, storing heat in the phase-change heat storage material, and storing redundant heat into the heat storage system;

2-3c) when the relative humidity is higher than 95% (namely more than or equal to 95%), closing the first heat storage fan set, the second heat storage fan set and the heat storage air door; starting a circulating fan and an air inlet and outlet of the drying kiln to carry out dehumidification treatment; removing the high-humidity medium in the drying kiln, introducing external fresh air into the drying kiln until the relative humidity in the drying kiln is reduced to 80 percent or the temperature in the drying kiln is lower than 45 ℃, closing the air inlet and outlet, and then starting a circulating fan and an auxiliary heater in the drying chamber;

2-4) when the temperature is higher than 65 ℃ (namely equal to or higher than 65 ℃), wherein

2-4a) when the relative humidity is lower than 95% (namely less than 95%), closing a circulating fan and an air inlet and an air outlet of the drying kiln; opening the first heat storage fan set, the second heat storage fan set and the heat storage air door, enabling a drying medium to flow into a heat storage box of the heat storage system under the action of the heat storage fan sets to heat the phase-change heat storage material, storing heat in the phase-change heat storage material, and storing redundant heat into the heat storage system;

2-4b) when the relative humidity is higher than 95% (namely more than or equal to 95%), closing the first heat storage fan set, the second heat storage fan set and the heat storage air door; starting a circulating fan and an air inlet and outlet of the drying kiln, carrying out dehumidification treatment, removing high-humidity media in the drying kiln, introducing external fresh air into the drying kiln until the relative humidity in the drying kiln is reduced to 80 percent or the temperature in the drying kiln is lower than 45 ℃, and closing the air inlet and outlet;

detecting the water content of the wood in the solar drying process, stopping the solar drying when the water content of the wood is less than or equal to 12%, and continuing the drying treatment if the water content of the wood is greater than 12%;

3) night time ventilation treatment

When the solar drying treatment is carried out to 18:00, the heat storage air door, the first heat storage fan unit, the second heat storage fan unit and the auxiliary heater are closed; opening an air inlet and outlet and a drying kiln circulating fan to perform night air exchange treatment; and measuring the temperature t of the medium in the kiln at the end of the ventilation treatment_whAnd relative humidity

4) Calculating the heat Q stored in the heat storage system_cAnd the lowest heat quantity Q required by the drying treatment of the closed kiln at night_min；

4A) Calculating the minimum heat Q required in the drying treatment process of the blind kiln at night according to the formula (2)_min；

In the formula (2), t_mzThe highest temperature of the medium in the drying kiln is the highest temperature of the medium in the drying kiln when the night kiln closing drying treatment is finished;

the maximum relative humidity of the medium in the drying kiln is obtained when the closing kiln drying treatment at night is finished; t is t_whThe temperature of a drying medium in the drying kiln is measured at the temperature of DEG C when the ventilation treatment in the drying kiln is finished;

the relative humidity of the drying medium in the drying kiln is obtained when the ventilation treatment in the evening of the drying kiln is finished; l is the longitudinal length of the drying kiln, m; w is the transverse width of the drying kiln, m; h is the vertical height of the drying kiln, m; k is 1.2 to 2.0;

4B) calculating the total heat Q stored by the heat storage system at the end of the night air exchange treatment according to a formula (3)_c

Q_c＝Mq_p (3)

In the formula (3), M is the mass of the phase-change heat storage material in the heat storage system, kg; q. q.s_pIs the latent heat released by the phase-change heat storage material with unit mass, kJ/kg;

5) drying treatment in a closed kiln at night

Closing the air inlet and outlet of the drying kiln after ventilation treatment at night, and performing the lowest heat Q required by the drying treatment of the kiln at night_minAnd heat quantity Q stored in heat storage system_cComparing;

5A) if Q is_c≤Q_minIf yes, starting the auxiliary heating assembly, closing the drying kiln circulating fan and the auxiliary heating assembly after the auxiliary heating is carried out for tau time at night, stopping the auxiliary heating, then starting the heat storage air door, the first heat storage fan set and the second heat storage fan set, using the energy stored in the heat storage system for night kiln closing and drying, and drying the wood in the kiln until the next day is 7: 00;

5B) if Q is_c≥Q_minClosing the drying kiln circulating fan, opening the heat storage air door, the first heat storage fan set and the second heat storage fan set, and using the energy stored by the heat storage system for night kiln closing and drying until the next day is 7: 00;

wherein, in the process of drying treatment in a closed kiln at night, the moisture content of the wood is measured, and if the moisture content of the wood is less than or equal to 12 percent, the drying treatment at night is stopped; if the moisture content of the wood is still higher than 12% after the completion of the kiln drying at night, continuing to perform drying treatment;

6) morning ventilation treatment

When the moisture content of the wood is higher than 12% at 7:00 of the next day, closing the heat storage air door, the first heat storage fan set and the second heat storage fan set, and opening the air inlet and outlet and the drying kiln circulating fan to perform morning ventilation treatment;

7) and (5) repeating the steps (2), (3), (4), (5) and (6) until the water content of the wood is less than or equal to 12 percent.

Wherein, t in step 1A)_mzIs 45-50 ℃; the above-mentioned

90% -95%; in the step 1B), the heat storage pipes are fixedly arranged in the heat storage tank in a staggered or sequential manner, preferably in a staggered manner.

In particular, the night time ventilation treatment time in step 3) is at least 0.5h, preferably 0.5-1h, and more preferably 0.75-1 h; the morning ventilation treatment in step 6) is carried out for a period of at least 0.5h, preferably 0.5-1h, more preferably 0.75-1 h.

Wherein t in the formula (2) in the step 4A)_mIs 45-50 ℃; the above-mentioned

90% -95%; and further t_mPreferably 48 ℃; the above-mentioned

Preferably 93%; k is preferably 1.2 to 1.5.

Particularly, when the phase-change heat storage material is paraffin in the step 4B), the total heat Q stored by the heat storage system at the end of the ventilation treatment in the evening_cThe method comprises the following steps:

4B-1), measuring the temperature of the phase-change heat storage material at the end of the night air exchange treatment, and calculating the average temperature t of the phase-change heat storage material_xp；

4B-2) and calculating the total heat Q stored by the heat storage system at the end of the night air exchange treatment according to the formula (3)_c

Q_c＝Mq_p (3)

Wherein: in the formula (3), M is the mass of the phase-change heat storage material in the heat storage system, kg; q. q.s_pDischarged as a unit mass of phase-change heat storage materialLatent heat, kJ/kg; wherein:

when t is_xp>60℃，q_p＝177kJ/kg；

When the temperature is 45 DEG C<t_xp<60℃,q_pCalculating according to the formula (4):

q_p＝exp(6024046+4917.2638t_xplnt_xp-203100.63t_xp/lnt_xp-352875.43lnt_xp

-166586600lnt_xp/t_xp+641180580/t_xp-989722200/t_xp ^1.5)

(4)

when t is_xp<At 45 ℃, the heat storage material does not generate phase change, and the stored energy can be almost ignored.

In particular, the nighttime auxiliary heating treatment time τ in step 5A) is calculated according to equation (5):

in the formula (5), tau is auxiliary heating time at night, and h; q_minThe lowest total heat required for the blind kiln drying treatment, kJ; q_ckJ, the heat stored by the heat storage material; p is the power of the auxiliary heating assembly, W.

Wherein, the night kiln-closing drying treatment is that no exhaust is generated in the drying process, the drying temperature of the wood is higher than 42 ℃, and the relative humidity in the medium reaches 90-95 percent to the maximum.

Particularly, the drying temperature of the wood in the night kiln drying treatment is 45-50 ℃, and the maximum relative humidity in the medium reaches 90-95%.

Compared with the prior art, the invention has the following advantages:

1. in the method, in the process of drying the wood by solar energy in the daytime, the high-temperature and high-humidity medium to be discharged out of the drying kiln is forced to flow through the heat storage system, the heat carried by the high-temperature and high-humidity medium in the solar drying process in the daytime is absorbed by the phase-change heat storage material, and then the absorbed heat is utilized to carry out kiln smoldering treatment at night, so that the wood is continuously dried, and the energy is obviously saved.

2. The method can accurately measure the heat stored in the heat storage system, provides accurate data support for the starting or starting running time of the auxiliary heater in the night kiln smoldering drying process, provides good data for the matching of the auxiliary heater, and realizes the accurate cooperation of the heater and the heat storage system.

3. The continuous predrying of the wood can be realized by the combined action of solar energy and auxiliary heat in the whole process, the control process is simple, and the automatic predrying process can be realized.

4. The heat storage system and the drying kiln in the drying device are separated, so that heat can be stored and released to the maximum extent; the heat storage system of the device absorbs the solar drying waste heat in the daytime and absorbs the heat of the high-temperature and high-humidity medium to be discharged from the drying kiln to store the solar energy to the maximum extent; in addition, the heat storage system absorbs heat when the temperature in the drying kiln is too high, is flexibly opened or closed, namely, the heat storage is flexible, provides auxiliary heat when the solar energy is insufficient, releases heat flexibly, obviously improves the utilization efficiency of the solar energy, reduces the emission of waste gas and avoids thermal pollution.

5. The method accurately calculates the heat stored in the heat storage system, provides accurate guidance for the opening or opening time of auxiliary heat at night or when the solar energy is insufficient, and accurately opens the auxiliary heat, thereby saving energy to the maximum extent; meanwhile, continuous drying in the daytime and kiln closing drying at night are adopted, so that drying stress generated in the drying process of the wood in the daytime can be eliminated, the moisture content gradient is reduced, drying defects such as cracking of the wood are further reduced, and the drying quality of the wood is improved.

Drawings

FIG. 1 is a schematic structural view of a solar continuous drying apparatus according to the present invention;

FIG. 2 is a schematic structural view of the first and second heat-storage fan sets and the common side wall of the drying kiln and the heat-storage system in the solar continuous drying device of the present invention;

fig. 3 is a schematic sectional view taken along line a-a in fig. 1.

Description of the reference numerals

1. A solar drying kiln; 11. a sunlight panel; 12. an air inlet and outlet; 13. an auxiliary heater; 14. a drying kiln circulating fan; 15. stacking the materials; 16. a common side wall; 2. a heat storage tank; 3. a heat storage pipe; 4. a heat storage pipe frame; 5. a first heat storage fan set; 5A, a second heat storage fan set; 6. a heat storage damper; 7. a hygrothermograph; 8. a first air deflector; 8A and a second air deflector.

Detailed Description

The invention will be further described with reference to specific embodiments, and the advantages and features of the invention will become apparent as the description proceeds. These examples are illustrative only and do not limit the scope of the present invention in any way. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention, and that such changes and modifications may be made without departing from the spirit and scope of the invention.

Hereinafter, an apparatus and method for continuously drying wood using solar energy embodying the present invention will be described in detail with reference to the accompanying drawings.

Referring to fig. 1, the apparatus for continuously drying wood using solar energy of the present invention comprises a solar drying kiln 1, a heat storage system, and a detection system, wherein:

the top of the solar drying kiln is a PC sunlight plate 11 which can allow sunlight to penetrate; air inlet and outlet ports 12 are arranged on two sides of the drying kiln; an auxiliary heater 13 and a drying kiln circulating fan 14 are arranged above the inside of the drying kiln, and the heater and the circulating fan are positioned at the upper part of a material pile 15 piled in the drying kiln; the auxiliary heater provides heat for the wood when the solar energy is insufficient (namely the solar energy cannot provide enough heat source for drying the wood); the drying kiln circulation fan is used to circulate the drying medium, and is typically located in the middle of the auxiliary heater.

In the embodiment of the invention, the drying kiln is a top-air type solar drying kiln with an auxiliary heat source, namely, a drying kiln fan is arranged at the top, and other types of solar drying kilns are also suitable for the invention, such as a greenhouse type solar drying kiln.

The heat storage system is used for storing redundant heat in the solar drying process and storing heat in a high-temperature high-humidity drying medium to be discharged outside the drying kiln in the wood drying process, the heat storage system is arranged on the outer side of the longitudinal or transverse side wall of the drying kiln, as shown in fig. 1 and 3, in the specific embodiment of the invention, the heat storage system is positioned on the outer side of the longitudinal side wall of the drying kiln, and comprises: heat storage box 2, many root length of heat storage pipe 3, heat storage pipe support 4, first, second heat-retaining

fan group

5, 5A, heat-retaining air door 6 and two aviation baffles (be first aviation baffle 8, second aviation baffle 8A), wherein:

the heat storage box is positioned at the outer side of the longitudinal side wall of the drying kiln, is provided with a heat preservation and insulation layer (not shown in the figure), and shares one longitudinal or transverse side wall with the drying kiln, namely a common side wall 16 (the common longitudinal side wall is taken as an example in the embodiment of the invention); the heat storage pipe frame is arranged in the heat storage tank and used for placing a heat storage pipe, and the shape of the heat storage pipe is matched with that of the heat storage tank; the heat storage pipes are fixed in the heat storage pipe frame in a staggered or sequential manner; the heat storage pipe is a cylindrical pipe and is made of metal with excellent heat conduction performance; the first heat storage fan set, the second heat storage fan set and the heat storage air door are arranged on the common longitudinal side wall of the heat storage box and the drying kiln, wherein the first heat storage fan set and the second heat storage fan set are embedded on the common longitudinal side wall of the heat storage box and the drying kiln, as shown in fig. 2; a heat storage air door 6 is arranged on the side wall of each fan facing one side of the drying kiln, and the heat storage air door is matched with the heat storage fan in installation position and size; the drying medium circularly flows between the drying kiln and the heat storage box through the heat storage air door and the fan, the air door is closed, and the medium in the drying kiln cannot enter the heat storage box through the heat storage fan, as shown in fig. 1 and 3.

The 2 air deflectors are fixedly arranged on one side of the drying kiln and are positioned between the first heat storage fan set and the second heat storage fan set and fixedly connected with the common side wall, as shown in figures 1 and 2. The air deflector is vertically arranged, and the length direction of the air deflector is consistent with the vertical direction of the drying kiln. The first air deflector is close to the first heat storage fan set, and the second air deflector is close to the second heat storage fan set. The hot air sent into the drying kiln through the fan unit is directly sent into the timber pile, the hot air is prevented from flowing only in a gap between the timber pile and the side wall of the drying kiln, the timber pile does not flow into the timber pile, and the purpose of drying the timber by sending the stored heat to the timber pile cannot be achieved. The air deflector is connected with the common side wall, the height of the air deflector is the same as that of the heat storage device, and the width of the air deflector is 1/2-2/3 of the width of a gap between the material stack and the common side wall.

In the embodiment of the present invention, the shape of the heat storage tank is not limited to the rectangular parallelepiped shape, and other shapes are applicable to the present invention; the heat-retaining pipe support is similar to the test-tube rack, and the aluminum pipe is selected to the heat-retaining pipe, the size of aluminium system heat-retaining pipe: the outer diameter is 20mm, the inner diameter is 18mm, and the height is 800 mm;

the phase change heat storage material is packaged in the heat storage tube and used for absorbing heat energy and storing a heat source; the heat storage pipes are arranged on the heat storage pipe frame in order in a staggered or sequential manner (in the specific embodiment of the invention, the heat storage pipes are arranged in a staggered manner). As shown in fig. 1 and 3, the heat storage pipe is vertically arranged on the heat storage pipe frame, is perpendicular to the ground, and is perpendicular to the flowing direction of the drying medium between the drying kiln and the heat storage tank, that is, the drying medium flows between the drying kiln and the liquid storage tank under the blowing action of the heat storage fan.

And temperature sensors are arranged in the heat storage pipes fixedly arranged in the heat storage pipe frame and used for measuring the temperature of the heat storage materials in the heat storage pipes, and the temperature of the phase-change heat storage materials in the heat storage system is the average value of the measured values of the temperature sensors and used for calculating the heat stored in the heat storage system. The temperature sensor is connected by wires (not shown) to a temperature recorder (not shown) external to the thermal storage system.

As shown in fig. 2, the first heat storage fan set and the second heat storage fan set respectively comprise N fans, wherein N is an integer and is greater than or equal to 2, and the axis of each fan is perpendicular to the side wall; the first heat storage fan set 5 is arranged at the front end of the side wall shared by the drying kiln and the heat storage box, the second heat storage fan set 5A is arranged at the rear end of the side wall shared by the drying kiln and the heat storage box, the fans of the first heat storage fan set and the second heat storage fan set are respectively arranged along the vertical direction of the drying kiln and are respectively positioned on the same straight line, and the installation heights of the fans of the first heat storage fan set and the second heat storage fan set are corresponding to each other and are the same in height. The fans in each fan set divide the side wall into N +1 parts along the vertical direction of the side wall, and the fans generally divide the side wall into N +1 equal parts along the vertical direction of the side wall.

In the specific embodiment of the invention, a first heat storage fan set is arranged at the front end of a common longitudinal side wall and comprises 2 fans; the second heat-storage fan set is arranged at the rear end of the common longitudinal side wall and comprises 2 fans for illustration. The fan of each fan group divides the side wall into 3 equal parts along the vertical direction of the side wall.

The first heat storage fan set and the second heat storage fan set promote the drying medium to circularly flow between the drying kiln and the heat storage box, namely in the process of solar drying treatment in the daytime, when the temperature or/and the humidity of the medium are increased, the high-temperature high-humidity medium in the kiln is forcibly sent into the heat storage system, and is circulated between the drying kiln and the heat storage box to store heat; and forcibly feeding the medium in the heat storage system into a drying kiln in the continuous wood drying process at night to continuously dry the wood.

In the heat storage or heat supply process, the first heat storage fan set and the second heat storage fan set are in opposite rotation directions, so that a drying medium circularly flows between the drying kiln and the heat storage box, namely when the fan of the first heat storage fan set rotates forwards to bring the medium in the drying kiln into the heat storage box, the fan of the second heat storage fan set rotates reversely to send the medium in the heat storage box into the drying kiln, and vice versa; that is, when the first fan unit supplies air to the heat storage system, the second fan unit draws air to the interior of the heat storage system, otherwise, when the second fan unit supplies air to the interior of the heat storage system, the first fan unit draws air to the interior of the heat storage system so as to form good circulation;

the detection system comprises: a thermo-hygrometer 7 and a moisture content meter for wood (not shown in the figure); wherein: the hygrothermograph 7 is used for measuring the temperature and the relative humidity of a drying medium in the drying kiln, is respectively positioned on the side wall of the drying kiln corresponding to the air inlet end and the air outlet end of the material pile, and is positioned on the vertical central line of the side wall of the drying kiln on the same side of the hygrothermograph on the inner wall of the same side and is vertically arranged along the drying kiln; a wood moisture content meter (i.e., a wood moisture meter, not shown) for measuring the moisture content of the wood, the wood moisture meter being installed at the upper, middle and lower portions of the stack, and finally obtaining the average moisture content of the wood by measuring the average value.

At least 4 hygrothermographs in the embodiment of the invention are illustrated as an example, as shown in fig. 1, 2 hygrothermographs are arranged on the inner wall of the air inlet end side of the stack, the other 2 hygrothermographs are arranged on the inner wall of the air outlet end side of the stack, and the hygrothermographs on the inner wall of the same side are positioned on the vertical central line of the longitudinal side wall of the drying kiln and are vertically arranged along the drying kiln. The wood moisture content tester selects a contact pin type or an induction type wood moisture meter. The hygrothermograph and the wood moisture tester are connected with an external controller through leads, and the measured data is output and recorded.

The working principle of the wood solar continuous drying device with the heat storage function is as follows:

in the invention, the wood is subjected to solar drying treatment in the daytime, namely, the wood is dried by providing heat energy for the wood to be dried by using a solar energy or/and auxiliary heat system in the daytime; and (3) performing kiln closing drying treatment on the wood at night, namely, providing heat energy for the wood to be dried by utilizing the heat stored by the heat storage system or/and the auxiliary heat system, and drying the wood.

Daytime solar drying treatment temperature t_dLess than 68 deg.C (maintained at 60-65 deg.C); in the process of drying treatment of the night kiln closing, a heat storage system or/and an auxiliary heater are/is used for heating a drying medium, and moisture in the wood is promoted to be removed, so that the wood can be dried in the process of closing the kiln at night, and the temperature t of the medium in the drying kiln is ensured when the treatment of the kiln closing at night is finished_mAt 45-50 deg.C; relative humidity of medium

Maximum between 90% and 95%, t_mSpecific solar drying temperature t_dLow by 15 ℃.

Description of the drawings: solar drying is mostly used for 5-10 months, and a solar drying base can be established only in an area suitable for solar drying, so that the temperature and the relative humidity in autumn are the lowest values in the process of using solar drying, and the consumption of heat storage materials can reach the maximum value by using the value taking mode. The kiln is suitable for most areas with dry solar energy, and the temperature in the kiln can be increased to about 65 ℃ by the solar energy in summer. In order to ensure the wood pre-drying quality and maximally save energy, the drying temperature t in the solar drying process_dIs selected to be less than 68 deg.C (60 deg.C)-65 ℃); in order to more fully utilize the waste heat of solar energy, reduce the opening of auxiliary heat in the kiln closing process and ensure that the temperature required by wood drying is not lower than 42 ℃ (the industry experience shows that the drying rate is too slow to be beneficial to the actual production process), t_mThe temperature is usually 45-50 deg.C, to ensure wood drying in kiln at night, the relative humidity in the medium is maximized as much as possible

Should be between 90% and 95%, so the temperature t at the end of the kiln-closing treatment_mThe temperature is about 15 ℃ lower than the solar drying temperature, so the solar drying is selected to be between 60 and 65 ℃; t is t_mzIs 45-50 ℃;

is 90 to 95 percent. ) The process flow of the invention for continuously drying wood by using solar energy is shown in table 1.

Table 1 process for continuous drying of wood according to the invention

1. Solar drying process

The aim of drying the wood is achieved by providing heat energy for the wood to be dried by a solar energy or/and auxiliary heat system in the daytime, wherein the drying temperature t is controlled in the solar drying treatment process_d60-65 ℃; the heat storage system is supplemented by auxiliary heat, and parameters in the kiln smoldering process are combined, so that the maximum heat storage capacity of the heat storage system can meet the requirement of wood drying at night.

In a solar drying process, wherein:

1) when the temperature is lower than 45 ℃, the auxiliary heater is started, the circulating fan of the drying kiln is dried, and the first heat storage fan set, the second heat storage fan set, the heat storage air door and the air inlet and outlet are closed to perform auxiliary heating and drying;

2) with the drying process, the temperature is higher than 45 deg.C and lower than 60 deg.C, wherein

2a) When the relative humidity is lower than 80%, the auxiliary heater 13 is started to perform auxiliary heating, and meanwhile, the drying kiln circulating fan is started to close the first heat storage fan unit, the second heat storage fan unit, the heat storage air door and the air inlet and outlet;

2b) when the relative humidity is higher than 80% and lower than 95%, closing a circulating fan and an air inlet and outlet of the drying kiln, and opening a first heat storage fan set, a second heat storage fan set and a heat storage air door to store redundant heat into a heat storage system;

2c) when the relative humidity is higher than 95%, closing the first and second heat storage fan sets and the heat storage air doors, and opening a circulating fan and an air inlet and outlet of the drying kiln to perform dehumidification treatment;

3) when the temperature is higher than 60 ℃ and lower than 65 ℃, wherein

3a) When the relative humidity is higher than 80%, closing the circulating fan and the air inlet and outlet of the drying kiln, and opening the first heat storage fan set, the second heat storage fan set and the heat storage air door to store redundant heat into the heat storage system;

3b) when the relative humidity is lower than 80%, a drying kiln circulating fan is started, an air inlet and outlet, the first heat storage fan set, the second heat storage fan set and the heat storage air door are closed, and wood drying is carried out;

4) when the temperature is higher than 65 ℃, wherein

4a) When the relative humidity is lower than 95%, closing the drying kiln circulating fan 14 and the air inlet and outlet 12, opening the first heat storage fan set 5 and the second heat storage fan set 5A and the heat storage air door 6, and storing redundant heat into the heat storage system;

4b) and when the relative humidity is higher than 95%, closing the first heat storage fan set, the second heat storage fan set and the heat storage air door, and opening the circulating fan and the air inlet and outlet of the drying kiln to perform dehumidification treatment.

And (3) monitoring the water content of the wood in real time in the solar drying process, reducing the water content of the wood to be less than or equal to 12 percent (usually 8-12 percent), and stopping drying.

2. Night time ventilation treatment

When the drying is carried out to 18:00 night, the drying kiln is subjected to night air exchange treatment, and high-temperature high-humidity drying media in the drying kiln are removedFeeding low-temperature and low-humidity medium (namely fresh air) in the external environment into a drying kiln, and performing ventilation treatment for at least 0.5h (usually more than or equal to 0.5h, preferably 0.5-1h) at night; recording the temperature t of the medium in the drying kiln at the end of the night air exchange treatment_whAnd relative humidity

And (3) monitoring the water content of the wood in real time in the ventilation treatment process at night, reducing the water content of the wood to less than or equal to 12 percent (usually 8-12 percent), and stopping drying.

3. Drying treatment at night

Carrying out night kiln closing drying treatment after night air exchange treatment, and carrying out kiln closing treatment without exhausting air at night in order to save the cost of workers (without the operation of workers) in the night drying process and improve the wood pre-drying quality (relieving the moisture content gradient and the generated drying stress in the wood in the daytime pre-drying process); wherein, the kiln smoldering process is not dehumidified, and the temperature t of the medium in the drying kiln is recorded when the kiln smoldering process is finished at night_mAnd relative humidity

In the drying process of the kiln stuffiness at night, the heat stored by the heat storage system is used for drying the wood, if the stored heat is not enough to meet the requirement of drying the wood at night, the auxiliary heat system is used for supplementing heat, the supplemented heat is accurately calculated to ensure the drying temperature in the kiln stuffiness process, so that the moisture in the wood is removed, and the temperature t of the drying medium in the kiln is t when the kiln stuffiness is finished_mReaching 45-50 deg.C (preferably 48 deg.C) relative humidity

To 90-95% (preferably 93%).

In the embodiment of the invention, the temperature t of the drying medium in the kiln is the end of the kiln sealing treatment_mAt a relative humidity of 48 deg.C

93% for example, and the other t_mThe temperature of the mixture is between 45 and 50 ℃,

from 90 to 95% are suitable for use in the present invention.

And (3) monitoring the moisture content of the wood in real time in the process of the kiln covering treatment at night, reducing the moisture content of the wood to be less than or equal to 12 percent (usually 8-12 percent), and stopping drying.

4. Morning ventilation treatment

Performing morning ventilation treatment when the night kiln is closed and dried to the next day of 7:00, removing high-humidity drying medium in the drying kiln, feeding external environment medium (namely low-temperature low-humidity fresh air) into the drying kiln, performing morning ventilation treatment for at least 0.5h (usually more than or equal to 0.5h, preferably 0.5-1h), and recording the temperature t of the medium in the drying kiln when the morning ventilation treatment is finished_chAnd relative humidity

And (3) monitoring the moisture content of the wood in real time in the morning ventilation treatment process, reducing the moisture content of the wood to less than or equal to 12 percent (usually 8-12 percent), and stopping drying.

5. Solar drying process

And after the morning ventilation treatment is finished, sequentially and repeatedly carrying out solar drying treatment, night ventilation treatment, night drying treatment and morning ventilation treatment until the moisture content of the wood in the drying kiln is reduced to be less than or equal to 12% (usually 8-12%), and finishing the wood drying. The method for continuously drying the wood by utilizing the solar energy comprises the following specific steps:

according to the continuous drying process requirement of the wood, in order to ensure that the wood can be continuously dried in the kiln closing process at night and the lowest heat storage capacity of a heat storage system can dry out moisture in the wood, the lowest heat Q required in the kiln closing process at night is kq, wherein k is 1.2-2.0, and Q is the temperature of a medium in the drying kiln from t when the ventilation treatment at night is finished_whBecomes t_mRelative humidity of

Become into

The required heat, namely the temperature of the medium in the drying kiln at the end of the night kiln covering treatment is t_whBecomes t_mRelative humidity of

Become into

The amount of heat required for the media change.

1. Calculating the amount (M) of phase change heat storage material in the heat storage system

Calculating the dosage M of the heat storage material in the continuous wood drying device according to the formula (1):

in the formula (1), M is the mass of the phase-change heat storage material in the heat storage system, kg, and H is the phase-change latent heat of the phase-change heat storage material, kJ/kg; t is t₁The average temperature of the drying kiln in the autumn (obtained by consulting weather data of the drying kiln in the autumn) is DEG C;

(ii) average relative humidity in autumn for use in drying kiln; t is t_mzThe maximum temperature t of the drying medium in the drying kiln at the end of the drying treatment of the drying kiln in the closed kiln at night_mzIs 45-50 ℃;

is the maximum relative humidity of the drying medium in the drying kiln when the drying treatment of the drying kiln is finished,

90% -95%; l is the longitudinal length of the drying kiln, m; w is the transverse width of the drying kiln, m; h is the vertical height of the drying kiln, m; k is coefficient, 1.2-2.0;wherein t is₁And

the value of (a) can be obtained by looking up the meteorological data of autumn of the dry kiln use land, t₁The temperature is between 20 and 30 ℃,

20 to 30 percent.

The phase-change heat storage material of the invention takes paraffin as an example, and other phase-change heat storage materials are also suitable, such as stearic acid, polyethylene glycol, alkane and the like. The H of the phase-change heat storage material paraffin is 177 kJ/kg. 2. Installation of heat storage system

Uniformly distributing phase-change heat storage materials into heat storage pipes, wherein the heat storage materials in each heat storage pipe are the same in loading amount; then, the heat storage pipes are vertically arranged on the heat storage pipe racks in a staggered or sequential manner, the heat storage pipe racks are placed in the heat storage tank, the axes of the heat storage pipes are perpendicular to the bottom surface of the drying kiln, and the distance between the heat storage pipes is 1-4 times (preferably 2.5 times) of the diameter of each heat storage pipe;

arranging a temperature sensor in the heat storage pipe, measuring the temperature of the phase change heat storage material in the heat storage pipe, averaging the measured temperature to obtain the average temperature of the heat storage material in the heat storage system, and accurately calculating to obtain the heat stored by the heat storage system;

3. wood stacking

Stacking one layer of partition bars and one layer of wood according to a conventional wood stacking method, stacking the wood in a drying kiln, and installing a wood moisture content tester for testing the moisture content of the wood on a vertical central line of a wood stack;

wherein, evenly install N (N is the integer, N is more than or equal to 0) branch timber moisture content apparatus along the direction of height of timber heap, evenly divide into (N +1) section along its direction of height with the timber heap, usually evenly install 3 branch timber moisture content apparatus in the direction of height of timber heap, lie in the 1/4 of timber heap height, 1/2 and 3/4 department respectively, the average value of the result of survey is got, marks as the moisture content of timber.

4. Solar drying process

Measuring the temperature and the relative humidity of the medium in the drying kiln by a hygrothermograph 7 beginning at 7:30-8:00 am, wherein:

4-1) when the temperature is lower than 45 ℃ (namely less than 45 ℃), starting an auxiliary heater and a circulating fan of a drying kiln; closing the first heat storage fan set, the second heat storage fan set, the heat storage air door and the air inlet and outlet, performing solar energy and auxiliary heating drying, and heating the wood in the stacking and drying kiln;

4-2) when the temperature is higher than 45 deg.C (i.e. > 45 deg.C) and lower than 60 deg.C (i.e. <60 deg.C) with the drying process, wherein

4-2a) when the relative humidity is lower than 80% (namely less than 80%), starting the auxiliary heater 13 and the circulating fan of the drying kiln; closing the first heat storage fan set, the second heat storage fan set, the heat storage air door and the air inlet and outlet, performing auxiliary heating, and performing solar energy and auxiliary heating drying;

4-2b) when the relative humidity is higher than 80% (namely more than or equal to 80%) and lower than 95% (namely less than 95%), closing a circulating fan and an air inlet and outlet of the drying kiln; opening the first and second heat storage fan sets and the heat storage air door, enabling the damp and hot drying medium to flow into a heat storage box of the heat storage system under the action of the heat storage circulating fan to heat the phase-change heat storage material, enabling the phase-change heat storage material to start storing heat, and storing redundant heat into the heat storage system; wherein if the auxiliary heater is in an on state, the auxiliary heater is turned off; if the auxiliary heater is in the off state, the auxiliary heater does not need to be started;

4-2c) when the relative humidity is higher than 95% (namely more than or equal to 95%), closing the first heat storage fan set, the second heat storage fan set and the heat storage air door; starting a circulating fan and an air inlet and outlet of the drying kiln to carry out dehumidification treatment; removing the high-humidity medium in the drying kiln, introducing external fresh air into the drying kiln until the relative humidity in the drying kiln is reduced to 80 percent or the temperature in the drying kiln is lower than 45 ℃, closing the air inlet and outlet, and then starting a circulating fan and an auxiliary heater in the drying chamber;

4-3) when the temperature is higher than 60 ℃ (60 ℃ or higher) and lower than 65 ℃ (65 ℃ or lower), wherein

4-3a) when the relative humidity is lower than 80% (namely less than 80%), starting a circulating fan of the drying kiln, closing the air inlet and outlet, the first heat storage fan set, the second heat storage fan set and the heat storage air door, and drying the wood;

4-3b) when the relative humidity is higher than 80% (namely more than or equal to 80%) and lower than 95% (namely less than 95%), closing a circulating fan and an air inlet and outlet of the drying kiln, opening the first heat storage fan set and the second heat storage fan set and the heat storage air door, enabling a damp and hot drying medium to flow into a heat storage box of the heat storage system under the action of the heat storage circulating fan, heating the phase-change heat storage material, starting heat storage of the phase-change heat storage material, and storing redundant heat into the heat storage system;

4-3c) when the relative humidity is higher than 95% (namely more than or equal to 95%), closing the first heat storage fan set, the second heat storage fan set and the heat storage air door; starting a circulating fan and an air inlet and outlet of the drying kiln to carry out dehumidification treatment; removing the high-humidity medium in the drying kiln, introducing external fresh air into the drying kiln until the relative humidity in the drying kiln is reduced to 80 percent or the temperature in the drying kiln is lower than 45 ℃, closing the air inlet and outlet, and then starting a circulating fan and an auxiliary heater in the drying chamber;

4-4) when the temperature is higher than 65 ℃ (namely ≥ 65 ℃), wherein

4-4a) when the relative humidity is lower than 95% (namely less than 95%), closing the drying kiln circulating fan 14 and the air inlet and outlet 12, opening the first and second heat storage fan sets 5 and 5A and the heat storage air door 6, and storing the redundant heat into the heat storage system;

4-4b) when the relative humidity is higher than 95% (namely more than or equal to 95%), closing the first heat storage fan set and the second heat storage fan set and the heat storage air door, opening the circulating fan and the air inlet and outlet of the drying kiln, performing moisture removal treatment, removing high-humidity media in the drying kiln, introducing external fresh air into the drying kiln until the relative humidity in the drying kiln is reduced to 80%, or the temperature in the drying kiln is lower than 45 ℃, and closing the air inlet and outlet.

Measuring the moisture content of the wood by a wood moisture content detector in the solar drying process, and stopping solar drying when the moisture content of the wood is less than or equal to 12% (usually 8-12%); if the moisture content of the wood is higher than 12%, continuing to perform drying treatment;

5. night time ventilation treatment

When the solar drying treatment is carried out to 18:00, the heat storage air door, the first heat storage fan set, the second heat storage fan set and the auxiliary heater are closed, the air inlet and outlet and the drying kiln circulating fan are opened, the high-humidity medium in the drying kiln is removed, and meanwhile, the external environment medium (namely fresh air of the external environment) gas is sent into the drying kiln to carry out the night air exchange treatment of the drying kiln;

the air exchange treatment time is more than or equal to 0.5h (usually 0.5-1.0h, preferably 0.75-1.0h), then the air inlet and outlet and the circulating fan of the drying chamber are closed, the relative humidity in the drying kiln is continuously collected by a hygrothermograph, and the temperature t of the medium in the drying kiln after the air exchange is finished at night is recorded_whAnd relative humidity

In general: t is t_whAnd

respectively similar to the temperature and the relative humidity at night when the solar drying kiln is located.

6. Calculating the minimum heat Q required by the drying treatment of the blind kiln at night_minHeat Q stored in the heat storage system_c

6-1) calculating the minimum heat Q required in the night blind kiln drying treatment process according to the formula (2)_min；

In the formula (2), t_mzThe highest temperature t of the medium in the drying kiln at the end of the night kiln sealing treatment_mIs 45-50 ℃;

the maximum relative humidity of the medium in the drying kiln is obtained when the kiln smoldering treatment at night is finished;

90-95%; t is t_whThe temperature of a drying medium in the drying kiln is measured by a hygrothermograph after the ventilation treatment of the drying kiln at night;

the relative humidity of the drying medium in the drying kiln is measured by a hygrothermograph after the ventilation treatment of the drying kiln at night; l is the longitudinal length of the drying kiln, m; w is the transverse width of the drying kiln, m; h is the vertical height of the drying kiln, m; k is 1.2-2.0. In the embodiment of the invention, t is_mAt a temperature of 48 c,

is 93% for example.

6-2) calculating the heat Q stored by the phase change heat treatment material of the heat storage system at the end of the night air exchange_c

Measuring the temperature of the phase-change heat storage material in the heat storage pipe by a temperature sensor of the heat storage system when the ventilation treatment at night is finished, and calculating the average temperature t of the phase-change heat storage material in the heat storage pipe_xp；

Calculating the total heat Q stored by the heat storage system at the end of the night air exchange treatment according to the formula (3)_c

Q_c＝Mq_p (3)

In the formula (3), M is the mass of the phase-change heat storage material in the heat storage system, kg; q. q.s_pIs latent heat emitted by the phase-change heat storage material with unit mass, kJ/kg, wherein:

A. when t is_xp≥60℃，q_p＝177kJ/kg；

B. When t is less than or equal to 45 DEG C_xp<60℃,q_pCalculating according to the formula (4):

C. when t is_xp<At 45 ℃, the heat storage material does not generate phase change, and the stored energy can be almost ignored;

7. drying treatment in a closed kiln at night

Comparing the minimum heat quantity Q required by the night kiln smoldering treatment_minHeat Q stored in heat storage system_cSize wherein

7-1) if Q_c≤Q_minAnd if the heat stored in the heat storage system cannot meet the minimum heat required by the treatment of the kiln smoldering at night, the circulating fan and the auxiliary heater of the drying kiln are started to perform auxiliary heating at night, and the auxiliary heating time tau is calculated according to the formula (5):

in the formula (5), tau is auxiliary heating time at night, and h; q_minThe lowest total heat required for smoldering the kiln, kJ; q_ckJ, the heat stored by the heat storage material; p is the power of the auxiliary heater, W (watts).

After the auxiliary heater is started for tau time, the drying kiln circulating fan and the auxiliary heater are closed, the heat storage air door, the first heat storage fan unit and the second heat storage fan unit are opened, the energy stored by the heat storage system is used for kiln closing treatment at night, and wood in the kiln is continuously dried;

7-2) if Q_c≥Q_minClosing the drying kiln circulating fan, opening the heat storage air door and the heat storage fan, directly using the energy stored by the heat storage system for kiln closing treatment at night, and drying the wood in the drying kiln until the next morning is 7: 00;

in the process of drying in a kiln at night, measuring the moisture content of the wood by a wood moisture content detector, and stopping the kiln at night if the moisture content of the wood is less than or equal to 12% (usually 8-12%); if the moisture content of the wood is still higher than 12% after the night kiln-closing treatment is finished, continuing to perform drying treatment;

8. morning ventilation treatment

Closing the heat storage air door, the first heat storage fan set and the second heat storage fan set when the moisture content of the wood is still higher than 12 percent (namely, higher than 12 percent) after the night kiln closing drying treatment is carried out till the next day is 7: 00; opening an air inlet and outlet and a drying kiln circulating fan, removing high-humidity medium in the drying kiln, simultaneously sending external environment medium (namely fresh air of the external environment) gas into the drying kiln, and performing morning ventilation treatment on the drying kiln, wherein the ventilation treatment time is more than or equal to 0.5h (usually 0.5-1.0h, preferably 0.75-1 h);

9. closing the air inlet and outlet, the heat storage air door, the first heat storage fan unit and the second heat storage fan unit after the morning ventilation treatment of the drying kiln is finished; and (3) starting a circulating fan and an auxiliary heater of the drying kiln to carry out solar drying treatment, repeating the steps 4-8, continuously monitoring the moisture content of the wood pile in each step until the moisture content of the wood is less than or equal to 12% (usually 8-12%), and stopping the drying treatment.

Example 1

In the embodiment, the fir is taken as an example for explanation, and other woods such as poplar, fir, eucalyptus, etc. are all suitable for the invention; the drying kiln is built in northern China for example, wherein the length, width and height of the solar drying kiln are 6m, 3m and 4m, and solar drying kilns with other sizes are also suitable for the invention; the heat storage material takes paraffin as an example, wherein the phase change latent heat H of the paraffin is 177 kJ/kg; other phase change heat storage materials are suitable for use in the present invention, such as stearic acid, polyethylene glycol, and the like.

Looking up autumn meteorological data of the location of the drying kiln to obtain the average air temperature t of the location of the drying kiln in autumn₁(25-35 ℃ C.), average relative humidity

(20-30%) and therefore t is given in this example₁Is 30 ℃;

the content was 25%. An aluminum pipe with the outer diameter of 20mm, the inner diameter of 18mm and the height of 800mm is used as a heat storage pipe for packaging the phase change heat storage material, and aluminum pipes with other sizes are also suitable for the invention; in addition to aluminum tubes, other copper tubes, iron tubes, and alloys are also suitable for use in the present invention.

In order to ensure continuous drying of the wood at night and save heat energy, the invention stores the solar energy and the energy of the high-temperature and high-humidity medium to be discharged in the drying kiln in the process of carrying out solar drying on the wood in the daytime.

1. Calculating the amount (M) of phase change heat storage material

Calculating the consumption M of the heat storage material required by the kiln-closing drying of the wood in the drying kiln according to the formula (1);

in the formula (1), M is the mass of the phase-change heat storage material in the heat storage system, kg; h is phase change latent heat of the heat storage material paraffin, 177 kJ/kg; t is t₁The average temperature of the drying kiln in the autumn (obtained by consulting weather data of the drying kiln in the autumn) is DEG C;

(ii) average relative humidity in autumn for use in drying kiln; t is t_mzThe highest temperature of a drying medium in the drying kiln is the temperature of the drying medium in the drying kiln when the drying treatment of the drying kiln is finished in a closed kiln at night (namely 7:00 hours the next day);

the maximum relative humidity of the drying medium in the drying kiln at the end of the drying treatment of the drying kiln in the closed kiln at night (namely 7:00 hours the next day); l is the longitudinal length of the drying kiln, m; w is the transverse width of the drying kiln, m; h is the vertical height of the drying kiln, m; k is 1.2 to 2.0;

in the night stuffy kiln treatment process of continuous drying of the wood, in order to ensure the drying quality of the wood, fully utilize absorbed heat energy and reduce the starting of an auxiliary heat system, when the stuffy kiln drying is finished, the highest temperature t of a drying medium in a drying kiln_mzAt 48 ℃ (typically 45-50 ℃); maximum relative humidity

93% (typically 90% -95%); t is t₁Is 30 ℃;

is 25%; k is 1.4; and calculating to obtain the minimum phase change heat storage material paraffin mass M required in the wood kiln-closing drying process to be 86.37 kg.

2. Amount of heat storage tube

2-1) calculating the phase transition of the single root according to the formula (6)Mass m of heat storage tube packaging phase change heat storage material₀

m₀＝ρ_sπr_s ²h_s(6)

In the formula (6), m₀The mass of the heat storage material which can be packaged by each heat storage aluminum pipe is kg; rho_sIs the density of the paraffin wax, kg/m³(ii) a π, constant, 3.14; r is_sRadius of heat storage tube, r_s0.009 m; hs is the height of the heat storage pipe, and hs is 0.8 m;

quantity m of paraffin wax packaged in each heat storage aluminum pipe₀0.18 kg;

2-2) calculating the usage amount n of the heat storage aluminum pipe according to the formula (7)

In the formula (7), n is the number of the heat storage aluminum tubes; m is the mass of the phase-change heat storage material, kg; m is₀The mass kg of the phase change heat storage material packaged in a single heat storage tube. The number n of the heat storage aluminum tubes is 480.

3. Installation of heat storage pipe

Fixedly installing a heat storage aluminum pipe packaged with paraffin in a heat storage box in a staggered manner, installing a temperature sensor in the heat storage pipe, measuring the temperature of a phase change heat storage material in the heat storage pipe, and calculating the average temperature t of the phase change heat storage material_xp；

The arrangement of the heat storage tubes is applicable to the present invention in addition to the forking arrangement, the in-line arrangement or other arrangements known in the art.

4. Wood stacking

According to the conventional wood stacking method, a layer of parting strips and a layer of wood strips are stacked, wood is stacked in a drying kiln, at least 2 wood moisture content measuring instruments 42 are arranged on a central line of a wood pile in the vertical direction, the moisture content of the wood is measured in real time, the moisture content measuring instruments are uniformly arranged on the vertical central line of the wood pile, and the moisture content of the wood is an average value of the measured values of the moisture content measuring instruments.

5. Solar drying process

5-1) when the temperature is lower than 45 ℃ (namely <45 ℃), starting an auxiliary heater and a circulating fan of a drying kiln; closing the first heat storage fan set, the second heat storage fan set, the heat storage air door and the air inlet and outlet, performing solar energy and auxiliary heating drying, and heating the wood in the stacking and drying kiln;

5-2) when the temperature is higher than 45 deg.C (i.e. > 45 deg.C) and lower than 60 deg.C (i.e. <60 deg.C) with the drying process, wherein

5-2a) when the relative humidity is lower than 80% (namely less than 80%), starting an auxiliary heater and a circulating fan of the drying kiln; closing the first heat storage fan set, the second heat storage fan set, the heat storage air door and the air inlet and outlet, performing auxiliary heating, and performing solar energy and auxiliary heating drying;

5-2b) when the relative humidity is higher than 80% (namely more than or equal to 80%) and lower than 95% (namely less than 95%), closing a circulating fan and an air inlet and outlet of the drying kiln; opening the first and second heat storage fan sets and the heat storage air door, enabling the damp and hot drying medium to flow into a heat storage box of the heat storage system under the action of the heat storage fan sets to heat the phase-change heat storage material, enabling the phase-change heat storage material to start heat storage, and storing redundant heat into the heat storage system; wherein if the auxiliary heater is in an on state, the auxiliary heater is turned off; if the auxiliary heater is in the off state, the auxiliary heater does not need to be started;

5-2c) when the relative humidity is higher than 95% (namely more than or equal to 95%), closing the first heat storage fan set, the second heat storage fan set and the heat storage air door; starting a circulating fan and an air inlet and outlet of the drying kiln to carry out dehumidification treatment; removing the high-humidity medium in the drying kiln, introducing external fresh air into the drying kiln until the relative humidity in the drying kiln is reduced to 80 percent or the temperature in the drying kiln is lower than 45 ℃, closing the air inlet and outlet, and then starting a circulating fan and an auxiliary heater in the drying chamber;

5-3) when the temperature is higher than 60 ℃ (60 ℃ or higher) and lower than 65 ℃ (65 ℃ or lower), wherein

5-3a) when the relative humidity is lower than 80% (namely less than 80%), starting a circulating fan of the drying kiln; closing the air inlet and outlet, the first heat storage fan set, the second heat storage fan set and the heat storage air door, and drying the wood;

5-3b) when the relative humidity is higher than 80% (namely more than or equal to 80%), closing a circulating fan and an air inlet and outlet of the drying kiln; opening the first and second heat storage fan sets and the heat storage air door, enabling the damp and hot drying medium to flow into a heat storage box of the heat storage system under the action of the heat storage circulating fan to heat the phase-change heat storage material, storing heat in the phase-change heat storage material, and storing redundant heat into the heat storage system;

5-3c) when the relative humidity is higher than 95% (namely more than or equal to 95%), closing the first heat storage fan set, the second heat storage fan set and the heat storage air door; starting a circulating fan and an air inlet and outlet of the drying kiln to carry out dehumidification treatment; removing the high-humidity medium in the drying kiln, introducing external fresh air into the drying kiln until the relative humidity in the drying kiln is reduced to 80 percent or the temperature in the drying kiln is lower than 45 ℃, closing the air inlet and outlet, and then starting a circulating fan and an auxiliary heater in the drying chamber;

5-4) when the temperature is higher than 65 ℃ (namely not less than 65 ℃), wherein

5-4a) when the relative humidity is lower than 95% (namely less than 95%), closing the circulating fan and the air inlet and outlet of the drying kiln; the first and second heat storage fan sets 5 and 5A and the heat storage air door 6 are opened, the damp and hot drying medium flows into the heat storage box of the heat storage system under the action of the heat storage circulating fan to heat the phase-change heat storage material, the phase-change heat storage material stores heat, and redundant heat is stored in the heat storage system;

5-4b) when the relative humidity is higher than 95% (namely more than or equal to 95%), closing the first heat storage fan set, the second heat storage fan set and the heat storage air door; and starting a circulating fan and an air inlet and outlet of the drying kiln to carry out dehumidification treatment, removing high-humidity media in the drying kiln, introducing external fresh air into the drying kiln until the relative humidity in the drying kiln is reduced to 80 percent or the temperature in the drying kiln is lower than 45 ℃, and closing the air inlet and outlet.

Measuring the water content of the wood in the solar drying process, and stopping the solar drying when the water content of the wood is less than or equal to 12%; if the moisture content of the wood is higher than 12%, continuing to perform drying treatment;

6. night time ventilation treatment

6-1) when the solar drying treatment is carried out to 18:00, closing the heat storage air door, the first heat storage fan set, the second heat storage fan set and the auxiliary heater; opening an air inlet and outlet and a drying kiln circulating fan, removing high-humidity media in the drying kiln, and simultaneously sending external environment medium gas into the drying kiln to perform night air exchange treatment on the drying kiln;

6-2) closing the air inlet and outlet and the drying chamber circulating fan after the air exchange treatment time is 1h, measuring the relative humidity in the drying kiln through a hygrothermograph, and recording the temperature t of the medium in the drying kiln after the air exchange is finished at night_whAnd relative humidity

The temperature of the phase-change material in the heat storage pipe is measured by a temperature sensor in the heat storage pipe of the heat storage system, and the average temperature t of the phase-change heat storage material is calculated_xp；

6-3) calculating the minimum heat Q required by the drying treatment of the blind kiln at night according to the formula (2)_min；

T in formula (2)_mzThe highest temperature of the drying medium in the drying kiln is the end of the blind kiln drying treatment, t_mIs 48 ℃;

the maximum relative humidity of the drying medium in the drying kiln is the end of the kiln-closing treatment,

is 95 percent; l is the longitudinal length of the drying kiln, m; w is the transverse width of the drying kiln, m; h is the vertical height of the drying kiln, m; k is 1.2-2.0.

Wherein, t_wh，

The actual measurement in the drying process is taken as the standard, for example: if it is determinedT of_wh＝35℃，

K is 1.4, and the lowest heat Q required by the night kiln-closing treatment is obtained_min＝14066.6KJ。

6-4) calculating the total heat Q stored by the heat storage system at the end of the night air exchange treatment according to the formula (3)_c：

Q_c＝Mq_p (3)

6-4A) when t_xp≥60℃，q_p＝177kJ/kg；

6-4B) when t is more than or equal to 45 DEG C_xp<60℃，q_pCalculating according to the formula (4):

q_p＝exp(6024046+4917.2638t_xplnt_xp-203100.63t_xp/lnt_xp-352875.43lnt_xp

-166586600lnt_xp/t_xp+641180580/t_xp-989722200/t_xp ^1.5)

(4)

6-4C) when t_xp<At 45 ℃, the heat storage material does not generate phase change, and the stored energy can be almost ignored;

for example: the average temperature t measured by the phase-change heat storage material when the ventilation treatment is finished in the evening_xpAt 62 ℃, the total heat Q stored by the heat storage system_c15287.49 KJ.

7. Kiln treatment at night

7-1) if Q_c≤Q_minIf the heat stored in the heat storage system can not meet the heat required by the kiln, the drying kiln circulating fan and the heater are started to perform auxiliary heating at night, the auxiliary heating time tau at night is calculated according to the formula (5),

in the formula (5), tau is auxiliary heating time at night, and h; q_minThe total heat required for the kiln drying is kJ; q_ckJ, the heat stored by the heat storage material; p is the power of the auxiliary heater, W (watts).

After the auxiliary heater is started for tau time, the drying kiln circulating fan and the auxiliary heater are closed, the air door of the heat storage system and the heat storage fan are opened, the energy stored by the heat storage system is used for kiln smoldering treatment at night, and wood in the drying kiln is dried;

7-2) if Q_cIf the temperature is more than or equal to Q, the circulating fan and the auxiliary heater of the drying kiln are closed, the heat storage air door and the heat storage fan are opened, the energy stored by the heat storage system is directly used for the kiln smoldering treatment at night, and the wood in the drying kiln is dried;

qc measured in examples of the invention>Q_minClosing the drying kiln circulating fan and the auxiliary heater, opening the heat storage air door and the heat storage fan, directly using the energy stored in the heat storage system for kiln closing at night, and drying the wood;

in the process of the nighttime kiln closing treatment, the moisture content of the wood is measured by a wood moisture content detector, and the nighttime kiln closing treatment is stopped if the moisture content of the wood is less than or equal to 12%; if the moisture content of the wood is still higher than 12% after the night kiln-closing treatment is finished, continuing to perform drying treatment;

8. morning ventilation treatment

When the stuffy kiln drying treatment is carried out to 7:00 of the next day, the moisture content of the wood is still higher than 12%, and then the heat storage air door, the first heat storage fan set and the second heat storage fan set are closed; opening an air inlet and outlet and a drying kiln circulating fan, removing high-humidity media in the drying kiln, simultaneously sending external environment medium (namely fresh air of the external environment) gas into the drying kiln, and performing morning ventilation treatment on the drying kiln, wherein the ventilation treatment time is 1 h; measuring the relative humidity in the kiln by a hygrothermograph and recording the temperature and relative humidity t of the medium in the kiln after the end of the morning ventilation_chAnd

9. closing the air inlet and outlet, the heat storage air door, the first heat storage fan unit and the second heat storage fan unit after the morning ventilation treatment of the drying kiln is finished; and (3) starting a circulating fan and an auxiliary heater of the drying kiln to carry out solar drying treatment, repeating the steps 5-8, continuously monitoring the moisture content of the wood pile in each step until the moisture content of the wood is less than or equal to 12%, and stopping the drying treatment.

Example 2

Except that t is determined in step 6-3) during the night time ventilation treatment_wh＝30℃，

K is 1.4, and the lowest heat Q required by the night kiln-closing treatment is obtained_min15084.8 kJ; average temperature t of phase change heat storage material in step 6-4)_xpThe total heat Q stored by the heat storage system is 55 DEG C_c9166.13 kJ; in the process of drying in a closed kiln at night Q_c≤Q_minIf the heat stored in the heat storage system can not meet the heat required by the drying of the stuffy kiln, a circulating fan and a heater of the drying kiln are started to perform auxiliary heating at night, the auxiliary heating time tau at night is calculated according to a formula (5),

Taking 2500W as an example of the power of an auxiliary heater, the auxiliary heating time tau at night is 2.367h, after the auxiliary heater is started for 2.367h, a drying kiln circulating fan and the auxiliary heater are closed, an air door of a heat storage system and the heat storage fan are opened, the energy stored in the heat storage system is used for kiln closing treatment at night, and the rest is the same as that in the example 1 except for drying wood in a drying kiln.

Claims

1. A method for continuously drying wood by using a device for continuously drying wood by using solar energy comprises a solar drying kiln, wherein an auxiliary heating assembly is arranged in the solar drying kiln, a circulating fan of the drying kiln is arranged on two sides of the drying kiln, and a heat storage system for storing solar heat in the wood drying process and heat of a high-temperature high-humidity drying medium to be discharged out of the drying kiln is arranged on two sides of the drying kiln and comprises a heat storage box and a plurality of heat storage pipes arranged in the heat storage box; the heat storage box is arranged on the outer side of the longitudinal or transverse side wall of the drying kiln, and a heat storage air door, a first heat storage fan set and a second heat storage fan set are arranged on the longitudinal or transverse side wall of the drying kiln, and are used for sending a drying medium in the drying kiln into the heat storage box, transferring the heat carried by the drying medium into a heat storage system and storing the heat in the heat storage system, and the heat storage box is characterized by comprising the following steps which are carried out in sequence:

（1）

in the formula (1), M is the mass of the phase change heat storage material in the heat storage system represented by kilogram as a metering unit, and H is the phase change latent heat value of the heat storage material represented by kJ/kg as a metering unit; t is t₁The average gas temperature value represented by taking the temperature as a measurement unit is obtained by consulting the meteorological data of the drying kiln in the autumn; phi is a₁(ii) average relative humidity in autumn for use in drying kiln; t is t_mzThe temperature is the highest temperature value which is represented by taking the temperature as a unit and is used for drying media in the drying kiln when the drying treatment of the drying kiln is finished in the process of closing the kiln at night; phi is a_mzThe maximum relative humidity of the drying medium in the drying kiln is the maximum relative humidity of the drying medium in the drying kiln when the drying treatment of the drying kiln is finished in the closed kiln at night; l is the longitudinal length value of the drying kiln characterized by taking meters as a metering unit; w is the transverse width value of the drying kiln characterized by taking meters as a metering unit; h is the vertical of the drying kiln characterized by the meter as the measurement unitTo a height value; k is 1.2 to 2.0;

2) solar drying process

2-1) when the temperature is lower than 45 ℃, starting an auxiliary heating assembly and a circulating fan of the drying kiln; closing the first heat storage fan set, the second heat storage fan set, the heat storage air door and the air inlet and outlet, performing solar energy and auxiliary heating drying, and heating the wood in the stacking and drying kiln;

2-2) with drying, at a temperature above 45 ℃ and below 60 ℃, wherein

2-2a) when the relative humidity is lower than 80%, starting an auxiliary heater and a drying kiln circulating fan; closing the first heat storage fan set, the second heat storage fan set, the heat storage air door and the air inlet and outlet, performing auxiliary heating, and performing solar energy and auxiliary heating drying;

2-2b) when the relative humidity is higher than 80% and lower than 95%, closing a circulating fan and an air inlet and outlet of the drying kiln; opening the first and second heat storage fan sets and the heat storage air door, allowing the drying medium to flow into the heat storage box under the action of the heat storage fan sets to heat the phase-change heat storage material, allowing the phase-change heat storage material to start heat storage, and storing redundant heat into the heat storage system; wherein if the auxiliary heater is in an on state, the auxiliary heater is turned off; if the auxiliary heater is in the off state, the auxiliary heater does not need to be started;

2-2c) when the relative humidity is higher than 95%, closing the first heat storage fan set, the second heat storage fan set and the heat storage air door; starting a circulating fan and an air inlet and outlet of the drying kiln to carry out dehumidification treatment; removing the high-humidity medium in the drying kiln, introducing external fresh air into the drying kiln until the relative humidity in the drying kiln is reduced to 80 percent or the temperature in the drying kiln is lower than 45 ℃, closing the air inlet and outlet, and then starting a circulating fan and an auxiliary heater in the drying chamber;

2-3) at a temperature of above 60 ℃ and below 65 ℃, wherein

2-3a) when the relative humidity is lower than 80%, starting a circulating fan of the drying kiln; closing the air inlet and outlet, the first heat storage fan set, the second heat storage fan set and the heat storage air door, and drying the wood;

2-3b) when the relative humidity is higher than 80% and lower than 95%, closing a circulating fan and an air inlet and outlet of the drying kiln; opening the first and second heat storage fan sets and the heat storage air door, allowing the drying medium to flow into the heat storage box under the action of the heat storage fan sets to heat the phase-change heat storage material, storing heat in the phase-change heat storage material, and storing redundant heat into the heat storage system;

2-3c) when the relative humidity is higher than 95%, closing the first heat storage fan set, the second heat storage fan set and the heat storage air door; starting a circulating fan and an air inlet and outlet of the drying kiln to carry out dehumidification treatment; removing the high-humidity medium in the drying kiln, introducing external fresh air into the drying kiln until the relative humidity in the drying kiln is reduced to 80 percent or the temperature in the drying kiln is lower than 45 ℃, closing the air inlet and outlet, and then starting a circulating fan and an auxiliary heater in the drying chamber;

2-4) at a temperature above 65 ℃, wherein

2-4a) when the relative humidity is lower than 95%, closing a circulating fan and an air inlet and outlet of the drying kiln; opening the first heat storage fan set, the second heat storage fan set and the heat storage air door, enabling a drying medium to flow into a heat storage box of the heat storage system under the action of the heat storage fan sets to heat the phase-change heat storage material, storing heat in the phase-change heat storage material, and storing redundant heat into the heat storage system;

2-4b) when the relative humidity is higher than 95%, closing the first heat storage fan set, the second heat storage fan set and the heat storage air door; starting a circulating fan and an air inlet and outlet of the drying kiln, carrying out dehumidification treatment, removing high-humidity media in the drying kiln, introducing external fresh air into the drying kiln until the relative humidity in the drying kiln is reduced to 80 percent or the temperature in the drying kiln is lower than 45 ℃, and closing the air inlet and outlet;

3) night time ventilation treatment

When the solar drying treatment is carried out to 18:00, the heat storage air door, the first heat storage fan unit, the second heat storage fan unit and the auxiliary heater are closed; opening an air inlet and outlet and a drying kiln circulating fan to perform night air exchange treatment; and measuring the temperature t of the medium in the kiln at the end of the ventilation treatment_whAnd relative humidity phi_wh；

（2）

In the formula (2), t_mzThe maximum temperature value of the medium is represented by taking the temperature as a measurement unit in the drying kiln when the night blind kiln drying treatment is finished; phi is a_mzThe maximum relative humidity of the medium in the drying kiln is obtained when the closing kiln drying treatment at night is finished; t is t_whThe temperature value of the drying medium is represented by taking the temperature as a measurement unit in the drying kiln when the ventilation treatment of the drying kiln is finished at night; phi is a_whThe relative humidity of the drying medium in the drying kiln is obtained when the ventilation treatment in the evening of the drying kiln is finished; l is the longitudinal length value of the drying kiln, which is characterized by taking meters as a metering unit, and m; w is the transverse width value of the drying kiln characterized by taking meters as a metering unit; h is a vertical height value of the drying kiln, which is characterized by taking meters as a metering unit; k is 1.2 to 2.0;

（3）

M in the formula (3) is the mass value of the phase-change heat storage material which is characterized by taking kilogram as a metering unit in the heat storage system; q. q.s_pLatent heat discharged from a unit mass of a phase-change heat storage material characterized by kJ/kg as a unit of measurementA calorific value;

5) drying treatment in a closed kiln at night

5A) if, if

If yes, starting the auxiliary heating assembly, closing the drying kiln circulating fan and the auxiliary heating assembly after the auxiliary heating is carried out for tau time at night, stopping the auxiliary heating, then starting the heat storage air door, the first heat storage fan set and the second heat storage fan set, using the energy stored in the heat storage system for night kiln closing and drying, and drying the wood in the kiln until the next day is 7: 00;

5B) if, if

Closing the drying kiln circulating fan, opening the heat storage air door, the first heat storage fan set and the second heat storage fan set, and using the energy stored by the heat storage system for night kiln closing and drying until the next day is 7: 00;

6) morning ventilation treatment

2. The method as claimed in claim 1, wherein the phase-change heat storage materials are packaged in the heat storage tubes, and the heat absorbed by the phase-change heat absorption materials is used for absorbing the solar heat in the drying process of the wood in the drying kiln and the heat carried by the high-temperature high-humidity drying medium to be discharged out of the drying kiln or the phase-change heat release to heat the wood in the drying kiln and dry the wood.

3. The method of claim 2, wherein the phase change heat absorbing material is selected from one or more of paraffin, stearic acid, polyethylene glycol, or alkane.

4. The method as set forth in claim 1, wherein said t in step 1A)_mzA value of 45-50; phi is said_mz90% -95%; in the step 1B), the heat storage pipes are arranged in the heat storage tank in a staggered or sequential manner.

5. The method as set forth in claim 1, wherein said t in step 1A)_mzA value of 48; phi is said_mzIs 93%; in the step 1B), the heat storage pipes are arranged in the heat storage tank in a staggered mode.

6. The method according to any one of claims 1 to 5, wherein the evening ventilation treatment in step 3) is carried out for a period of at least 0.5 h.

7. The method of claim 6, wherein the evening ventilation treatment time in step 3) is 0.5-1 h.

8. The method of claim 7, wherein the evening ventilation treatment time in step 3) is 0.75-1 h.

9. The method as claimed in any one of claims 1 to 5, wherein in step 4B) when the phase-change heat storage material is paraffin, the total heat Q stored in the heat storage system at the end of the evening ventilation treatment_cThe method comprises the following steps:

4B-1), measuring the temperature of the phase-change heat storage material at the end of the night air exchange treatment, and calculating the average temperature t_xp，℃；

4B-2) according to formula (3)Calculating the total heat Q stored by the heat storage system when the ventilation treatment at night is finished_c

（3）

Wherein: m in the formula (3) is a mass value of the phase-change heat storage material in the heat storage system, which is characterized by taking kilograms as a metering unit; q. q.s_pThe latent heat value emitted by the phase change heat storage material with unit mass represented by kJ/kg as a metering unit; wherein:

when t is_xpIs greater than an average temperature of 60 degrees Celsius, q_p= 177kJ/kg；

When t is_xpIs greater than the average temperature characterized in degrees Celsius of 45 and less than 60, q_pCalculating according to the formula (4):

（4）

when t is_xpWhen the value of (A) is less than the average temperature of 45 represented by the centigrade degree, the heat storage material does not generate phase change, and the stored energy is not counted.

10. The method as set forth in any one of claims 1 to 5, wherein the nighttime auxiliary heat treatment time τ in step 5A) is calculated in accordance with the formula (5):

（5）

in the formula (5), tau is a night auxiliary heating time value represented by taking hours as a metering unit; q_minThe lowest total heat value represented by kilojoule as a metering unit required by the blind kiln drying treatment, Q_cThe heat value stored by the heat storage material is characterized by kilojoule as a metering unit, and P is the power value of the auxiliary heating component which is characterized by watt as the metering unit.

11. The method according to any of claims 1 to 5, wherein the morning ventilation treatment in step 6) is carried out for a period of at least 0.5 h.

12. The method as claimed in claim 11, wherein the morning ventilation treatment time in step 6) is 0.5-1 h.

13. The method as claimed in claim 12, wherein the morning ventilation treatment time in step 6) is 0.75-1 h.