CN108286876A - A kind of new type solar energy liquid for heat collection type Recombinant Wood drying system - Google Patents

Abstract

The present invention adopts a new type of solar liquid heat collection technology wood drying system, which includes a solar liquid heat collection part, the heat collection part is composed of double-insert all-glass vacuum tubes connected in series and parallel, and the heat storage part is composed of double water tanks. To ensure the stability of the drying process, the heat collection working mode is a combination of constant temperature water discharge and temperature difference cycle; the auxiliary heat source part is composed of an air source heat pump, this joint working mode can timely compensate for the heat required for drying, and effectively reduces The use of electric energy saves energy; the heat exchange device is a 2-4 type heat exchanger, and the heat exchanger setting is shown in the attached drawing 3 of the manual. The air-air heat exchange device realizes the purpose of waste heat recovery; the air flow in the drying room is forced Convection, the exhaust fan in the room takes away the high-temperature and humid air in time to speed up the drying rate. The room is also equipped with steam spray equipment, temperature sensors, and humidity detectors to control and detect the drying process in time and improve the drying quality.

Description

A new type of solar liquid heat collection technology wood drying system

technical field

The invention relates to the technical field of solar heat utilization and wood drying, in particular to a novel solar liquid heat collection type technical wood drying system.

Background technique

As the market demand for high-tech wood gradually increases, the production and quality of high-tech wood have also received extensive attention. At present, in the production process of high-tech wood, natural drying and artificial drying are mostly used for the drying part of fresh slabs, and the former is mostly limited. Due to the site, climate, region and other conditions, the latter has the disadvantages of high energy consumption and high investment, which makes the drying of the board urgently requires a new drying method. The most concerned about the dry part of the slab is the source of its drying energy. As an inexhaustible clean energy, solar energy has also attracted attention at home and abroad. At present, solar liquid collectors have been widely used in various fields, and combining it with non-renewable energy The method for drying the slab has not yet been discovered, so there is an urgent need for a new type of solar liquid heat collection type technology wood drying system.

Contents of the invention

In order to solve the above-mentioned problems and save energy to the greatest extent, a new type of solar liquid heat collection technology wood drying system is provided. Combine the primary energy with the secondary energy through the solar liquid heat collector, and then use the heat exchange method to heat the outdoor air to realize the drying of the skin. The higher temperature outlet air is used to preheat the inlet air. The final gas can also be used to provide heat for the subsequent drying process of technological wood production to maximize energy utilization.

The technical scheme of the present invention is: this novel solar liquid heat collecting technology wood drying system is composed of two parts, namely the solar liquid heat collecting part and the technology wood veneer drying part, the two are connected by a heat exchanger to realize heat exchange. The design of this system adopts the hot air forced convection drying method of water-air heat exchange, and the heat of the whole system is provided by the solar liquid collector. The liquid heat collector part is composed of a heat collecting plate, a hot water tank and a control system, and the energy transfer process is: heat collector→water tank→heat exchanger (drying chamber)→water tank. The water storage tank is also equipped with an auxiliary heat source air source heat pump. According to the change of climatic conditions, the working mode of the collector is divided into three types: the collector works alone, the collector and the auxiliary heat source work together, and the auxiliary heat source works alone. The working mode is automatically adjusted by the control system according to the temperature change of the water tank.

The heat exchange part adopts a water-air heat exchanger, and the water from the constant temperature water tank exchanges heat with the outdoor preheated air to reach the temperature required for drying the board, wherein the outdoor air is preheated through the drying outlet The high-temperature gas and the outdoor normal-temperature gas are realized through the gas-gas heat exchange device, and the exhaust gas discharged after preheating can be used to provide heat for the bleaching or dyeing process of the board to maximize energy utilization.

The drying part of the slab is realized in the drying workshop. In order to reduce the convective heat loss between the drying room and the outdoor environment, rock wool with a small thermal conductivity is used as the wall insulation and energy-saving material, and the heat exchanger is placed on the shady side of the drying room. Reduce the uneven distribution of indoor temperature due to sunny weather. Temperature test points are set at the inlet and outlet of indoor air, and four humidity detection devices are evenly installed in the room. At the same time, it is also equipped with four spray steaming devices, which are used for spray steaming in the drying and preheating stage to make the humidity and temperature of the board uniform.

Compared with the prior art, the present invention has the following beneficial effects: the present invention realizes the combination of the solar liquid heat collection system and the wood drying system by adding a solar liquid heat collection type heat supply equipment on the basis of the original technological wood veneer drying, The energy compensation form of the air source heat pump improves the energy utilization rate, reduces the use of non-renewable energy, and achieves the purpose of energy saving and emission reduction. The working mode of the double water tanks can continuously provide stable heat to the drying system, which improves the drying quality of the slabs. Two different heat exchanger devices are used to realize the conversion of heat energy between heat storage medium and air, and solve the problem of waste heat recovery. At the same time, the form of hot air forced convection drying speeds up the drying process and improves the drying efficiency. The three working modes of the system maximize the use of solar energy to achieve the purpose of saving energy.

Description of drawings

Fig.1 The two-dimensional schematic diagram of the new solar liquid heat collection technology wood drying system, Fig.2 The schematic diagram of the drying principle of the solar liquid heat collector, Fig.3 The two-dimensional schematic diagram of the shell-and-tube heat exchanger, Fig.4 The drying control system of the new solar liquid heat collector flow chart.

Detailed ways

The design and working principle of the new solar liquid heat collection technology wood drying system are as follows.

As described in the solar liquid heat collection part: the solar heat collection part is an important part of the drying of technical wood. The heat source in the drying room is provided by the solar heat collection plate and the FM-40Q (R) type air source heat pump. The system is based on a single 5000 pieces of fresh poplar veneer skins were dried for the first time as a reference drying capacity design. The solar heat collection part is composed of 15 strings and 6 parallel double-inserted all-glass vacuum tubes. Between 0.7m and 1.6m, the distance between the front and back is 1.2m in the design, and the branches are placed in parallel. The diameter of the hot water supply pipe is 80mm, and the diameter of the return water pipe is 40mm. The polyurethane double casing with a middle thickness of 18mm is adopted. Insulation, the size of the water tank is 3000mm*3000mm*2800mm.

There are three working modes of the solar heat collection system, which are: the solar heat collection plate works alone, the solar heat collection plate and the air source heat pump work together, and the air source heat pump works alone. The heat collection system is initially set to open the valve 1-2 and the pump 2-1, let the city water enter the solar heat collection plate for heating, and finally enter the water storage tank for heat storage. When the solar radiation is sufficient, the 4-2 measurement When the point temperature is greater than or equal to 52°C, the valve 1-3 opens and the hot water enters the water storage tank. When the water level reaches the upper limit, the system adopts the temperature difference cycle, and finally makes the water temperature in the constant temperature water tank reach 75°C; when the solar radiation is insufficient, the combined Working mode; when the solar radiation is insufficient for a long time, the air source heat pump works alone. The design of the above working mode not only maximizes the use of green energy solar energy, but also minimizes the use of auxiliary energy to achieve the purpose of energy saving. The above-mentioned heat storage part adopts the form of double water tanks, which ensures the stability of energy supply during the drying process, thereby ensuring the quality of the dry skin.

Heat exchanger part: the heat exchanger part is divided into air-water heat exchange and air-air heat exchange. This design focuses on the air-water heat exchanger, and the heat exchanger is a 2-4 type heat exchanger. Its specific structure is shown in accompanying drawing 3 of specification sheet. Open valve 1-5, blower 6, and indoor fan 3 during heat exchange, the water side is controlled by valve 1-5, and the air side is controlled by blower 6. The inlet temperature of the water side of the heat exchanger is 75°C, the outlet temperature is 40°C, the inlet temperature of the air side is 25°C, and the outlet temperature is 55°C, using a counter-flow heat exchanger design.

Drying part of technical wood veneer:

The drying room is made of stainless steel corrugated board and rock wool to reduce the heat loss due to the wall of the drying room. The interior is evenly equipped with steam spraying facilities, humidity sensing devices, and temperature sensing devices at the entrance and exit, so as to Detect and regulate the operating status of the drying room at any time. In the early stage of drying, the steam spraying facilities are turned on to make the initial drying temperature and humidity of the slabs uniform, and to reduce the deformation and cracking of the slabs caused by internal stress during the drying process. The forced convection of hot air is adopted in the drying room, and the high-temperature air at the outlet is discharged for other purposes after passing through the heat exchange device, achieving the purpose of waste heat recovery.

Claims (8)

1. The new energy-saving solar liquid heat collection technology wood drying system is divided into four parts. The heat storage part realizes the conversion of solar energy and heat energy by absorbing solar radiation, and uses hot water as the heat storage medium to store the converted heat energy. The heat exchanger part realizes Heat energy is transferred from hot water to air and between gas and gas. The solar liquid collector produces hot water meeting a certain temperature condition under solar radiation, and the air source heat pump device performs compensation heating. 2. The initial setting is to close valve 1-1, valve 1-3, valve 1-4, valve 1-5, circulation pump 1-5, and open valve 1-2, circulation pump 2-1. 3. The system works in three ways: when the solar radiation is sufficient, the solar collector works alone; when the light is insufficient, the air source heat pump compensates for heating; when the light is not enough for a long time, the air source heat pump works alone. 4. The temperature difference between the water inlet temperature and the water outlet temperature of the solar collector is detected within 20 minutes, which is the heating time of the solar collector. Cycle heating time. 5. The solar heat collection plate is composed of 15 series and 6 parallel double-inserted all-glass vacuum tubes. The water tanks are in the form of double water tanks, one is a water storage tank and the other is a constant temperature water tank. 6. Use air-air heat exchanger to recover waste heat from exhaust air and preheat inlet air. 7. Spray and steam the board before drying to keep the temperature and humidity of the board uniform. The indoor fan is turned on during water-air heat exchange to realize forced convection heat transfer and speed up the drying process. 8. The water-air heat exchanger is placed inside the shady side of the drying room to reduce the temperature difference between the sunny side and the shady side.