Solar energy-ground source heat pump heat pump coupled biogas pool heating system and progress control method
Technical field
The invention belongs to the new energy development Application Areas, what relate to is a kind of heating system, and being specifically related to a kind of is with solar energy-ground source heat pump heat pump coupled biogas pool heating system and progress control method.
Background technology
The gradually exhaustion of fossil energy is so that a lot of countries begin sight is gathered newborn energy field in the world.The producing methane through anaerobic fermentation technology is utilized mode as a kind of biomass waste, and namely the recyclable energy can solve problem of environmental pollution again, therefore has been subject to the great attention of national governments.In China, to the end of the year 2005, national household biogas reaches 1,800 ten thousand families, year about 69 billion cubic meters of production biogas.Simultaneously, built evaluation of biogas project on husbandry farms 3500 places, big-and-middle-sized biogas engineering 700 places that the whole nation is built.
Yet at present biogas engineering industrialization also is faced with many difficult problems, and wherein one of maximum difficult problem is how to guarantee normal under the winter low temperature environment, full load aerogenesis.The biogas normal temperature fermentation need to be more than 15 ℃, and mesophilic digestion need to be about in the of 35 ℃, and thermophilic fermentation need to be about in the of 55 ℃.Studies show that: the same marsh gas raw materials is equivalent under 15 ℃ of conditions 12 months aerogenesis total amount in the methane gas producing total amounts of 35 ℃ of condition next months.Therefore, suitable temperature is the key that guarantees the operation of marsh gas fermentation process efficient stable.At present, the big-and-middle-sized biogas engineering of China all adopts mesophilic digestion technique basically, namely keeps the interior temperature of fermentation vat in 35 ± 2 ℃ of scopes.
Temperature often needs biogas engineering is equipped with a cover heating system in 35 ± 2 ℃ of scopes in the fermentation vat in order to keep.At present, common methane-generating pit heating mode has: the various ways such as combustion pond formula is heated, electrically heated, the heating of fossil energy hot water boiler, methane boiler are heated, marsh gas power generation exhaust-heat heating, solar heating and earth source heat pump heating.It is a kind of underground melt pit that fuel glows that carries out that is arranged on that combustion pond formula is heated, and the characteristics of this method are that disposable input inferior fuel is winter of incendivity, need not labor management, relatively are applicable to the residents biogas engineering; The electricity heating technology is to consume the higher-grade electric energy as cost, and energy saving is not high; Fossil energy hot water boiler contaminate environment, capacity usage ratio is low; Methane boiler requires higher to equipment and operative technique; Main and the biogas cogeneration engineering combination of marsh gas power generation exhaust-heat heating generally only is applied to the large-sized biogas engineering; The solar energy heating system finishes collection and the transmission of heat energy by solar thermal collection system, this energy saving of system environmental protection, simple to operate can realize automatic operation, but is subject to the impact of weather conditions, adds thermally labile; Earth source heat pump is heated and is had good energy-saving effect, but the operation of the long-term single heating pattern of earth source heat pump causes earth source heat pump COP to reduce so that subsurface temperature reduces.
Comprehensive more existing methane-generating pit adds the relative merits of temperature technique, the invention discloses a kind of solar energy-ground source heat pump heat pump coupled biogas pool heating system, and optimization design and the progress control method of this system are set forth.
Summary of the invention
The object of the present invention is to provide a kind of solar energy-ground source heat pump heat pump coupled biogas pool heating system and progress control method of multimode automatic switching operation.
The present invention is from energy cascade utilization and system energy efficiency coefficient (COPs) maximization, solar energy heating technology and ground source heat pump technology are effectively combined, can not satisfy the problem that methane-generating pit is heated and required to solve single solar energy heating system in overcast and rainy, winter, and the problems such as the subsurface temperature reduction that causes of throughout the year operation of single earth-source hot-pump system, coefficient of performance reduction.The coupled system optimization design and the progress control method that propose, well solved each pattern automatic switchover optimized operation problem of coupled system under solar energy heating area and heat pump installed capacity Optimized Matching problem, the Different climate condition, to reach whole system from the economy that is designed into operation, the purpose of energy-saving and environmental protection.
A kind of solar energy-ground source heat pump heat pump coupled biogas pool heating system that the present invention proposes is comprised of solar thermal collection system, heat pump, methane-generating pit heating system and sun power underground heat storage system, wherein:
Solar thermal collection system comprises solar full-glass vacuum tube heat collector 6, transfer hot water storage tank 7 and heat collector hot water recycle pump 9, transfer hot water storage tank the first water outlet 7a links to each other with the input terminus of heat collector hot water recycle pump 9, the output terminal of heat collector hot water recycle pump 9 connects the input terminus of solar full-glass vacuum tube heat collector 6, the output terminal of solar full-glass vacuum tube heat collector 6 connects transfer hot water storage tank the first water-in 7b, consists of the solar energy heating loop;
Heat pump comprises heat pump main frame 3, U-shaped ground heat exchanger 23, transfer hot water storage tank 7 and heat pump low temperature side recycle pump 12, heat pump main frame vaporizer 4 water outlets are divided into two-way after by the second vacuum breaker 22, first magnetic valve 14 of leading up to links to each other with the water inlet pipe of U-shaped ground heat exchanger 23, the return water pipe of U-shaped ground heat exchanger 23 connects the input terminus of heat pump low temperature side recycle pump 12 by electric T-shaped valve 13, the output terminal of heat pump low temperature side recycle pump 12 connects the water-in of heat pump main frame vaporizer 4, consists of heat pump the first low-temperature heat source loop; Another road connects transfer hot water storage tank the second water outlet 7c by the second magnetic valve 15, and transfer hot water storage tank the second water-in 7d consists of heat pump the second low-temperature heat source loop by the input terminus of electric T-shaped valve 13 connection heat pump low temperature side recycle pumps 12;
The methane-generating pit heating system comprises fermentation vat 1, coil heat exchanger 2, heat pump main frame 3, transfer hot water storage tank 7, the first heating cycle pump 10 and the second heating cycle pump 11, coil heat exchanger 2 is arranged at the bottom of the pool wall all around and pond of fermentation vat 1, transfer hot water storage tank the second water outlet 7c connects the input terminus of the first heating cycle pump 10, the output terminal of the first heating cycle pump 10 is by the water-in of the 3rd magnetic valve 16 terminal pad tube heat-exchanger 2, the water outlet of coil heat exchanger 2 connects transfer hot water storage tank the second water-in 7d by the 4th magnetic valve 17, consists of the first heating loop; The water outlet of heat pump main condenser 5 is by the water-in of the first vacuum breaker 19 terminal pad tube heat-exchanger 2, the water outlet of coil heat exchanger 2 connects the input terminus of the second heating cycle pump 11 by the 5th magnetic valve 18, the output terminal of the second heating cycle pump 11 connects the water-in of heat pump main condenser 5, consists of the second heating loop; Transfer hot water storage tank 7 second water outlet 7c connect the input terminus of the second heating ring pump 11, the output terminal of the second heating cycle pump 11 connects the water-in of heat pump main condenser 5, the water-in of the water outlet terminal pad tube heat-exchanger 2 of heat pump main condenser 5, the water outlet of coil heat exchanger 2 consists of the 3rd heating loop by the second water-in 7d of the 4th magnetic valve 17 connection transfer hot water storage tanks 7;
Sun power underground heat storage system comprises the first heating cycle pump 10, U-shaped ground heat exchanger 23, transfer hot water storage tank 7, transfer hot water storage tank the second water outlet 7c links to each other with the input terminus of the first heating cycle pump 10, the output terminal of the first heating cycle pump 10 links to each other with the water-in of U-shaped ground heat exchanger 23 by the 7th magnetic valve 21, the first magnetic valve 14 successively, the water outlet of U-shaped ground heat exchanger 23 is received transfer hot water storage tank the second water-in 7d through electric T-shaped valve 13, forms the sun power underground heat storage loop of a closure.
Among the present invention, the header end of solar full-glass vacuum tube heat collector 6 is equipped with the first temperature sensor 24, the second temperature sensor 25 is equipped with at transfer hot water storage tank 7 middle parts, fermentation vat 1 middle part one side is equipped with three-temperature sensor 26, on the U-shaped ground heat exchanger 23 1 side backwater mains the 4th temperature sensor 27 is housed.
Among the present invention, transfer hot water storage tank 7 bottoms are connected with level pressure expansion drum 8 and blow-off pipe.
The progress control method of the solar energy-ground source heat pump heat pump coupled biogas pool heating system that the present invention proposes, there are five kinds of operational modes in described system, is respectively: sun power direct heating pattern, solar energy-ground source heat pump series connection heating mode, solar heat pump heating mode, the independent heating mode of earth source heat pump and sun power underground heat storage pattern; Wherein:
(1) sun power direct heating pattern
When fermentation vat 1 interior temperature is lower than 32 ℃, and when water temperature was higher than 50 ℃ in the transfer hot water storage tank 7, system was according to sun power direct heating mode operation, the 3rd magnetic valve 16, the 4th magnetic valve 17 are opened, remaining closed electromagnetic valve, the first heating cycle pump 10 is opened all the other device shutdowns; By the first heating loop, that is: current pass through the second water outlet 7c of transfer hot water storage tank 7 successively, the first heating cycle pump 10, the 3rd magnetic valve 16, coil heat exchanger 2, the 4th magnetic valve 17, the second water-in 7d finally by transfer hot water storage tank 7 gets back to transfer hot water storage tank 7, so that fermentation vat 1 interior temperature reaches design requirements, water temperature is lower than 45 ℃ in 37 ℃ or the transfer hot water storage tank 7 when fermentation vat 1 interior temperature is higher than, and this pattern is out of service;
(2) solar energy-ground source heat pump series connection heating mode
When fermentation vat 1 interior temperature is lower than 32 ℃, and water temperature is lower than 45 ℃ and when being higher than 30 ℃ in the transfer hot water storage tank 7, system is according to the operation of solar energy-ground source heat pump series connection heating mode, this moment the first magnetic valve 14, the 4th magnetic valve 17, the 6th magnetic valve 20 is opened, all the other closed electromagnetic valves, electric T-shaped valve 13 guiding connect U-shaped ground heat exchanger 23 1 sides, the second heating cycle pump 11, heat pump low temperature side recycle pump 12 is opened, heat pump main frame 3 is opened, the low temperature side of heat pump main frame 3 moves according to the first low-temperature heat source loop, and the high temperature side of heat pump main frame 3 then operates to the methane-generating pit heating according to the 3rd heating loop; Temperature is higher than 37 ℃ in fermentation vat, and stopped heating is closed corresponding magnetic valve, water pump and heat pump set;
(3) solar heat pump heating mode
When fermentation vat 1 interior temperature is lower than 32 ℃, and water temperature is lower than 30 ℃ and above Ground during the buried tube heat exchanger return water temperature in the transfer hot water storage tank 7, system moves according to the solar heat pump heating mode, that is: the low-temperature water heating of sun power preparation uses as the low level heat energy of heat pump, preparing high-temperature-hot-water by heat pump set is the marsh gas fermentation pool heating, the second magnetic valve 15, the 5th magnetic valve 18 is opened, electric T-shaped valve 13 is communicated to the input terminus of heat pump low temperature side recycle pump 12 by transfer hot water storage tank the second water-in 7d, the second heating cycle pump 11, heat pump low temperature side recycle pump 12 is opened, and the heat pump main frame is opened; The low temperature side of heat pump main frame moves according to the second low-temperature heat source loop, and the high temperature side of heat pump main frame operates to the methane-generating pit heating according to the second heating loop.Temperature is higher than 37 ℃ in fermentation vat, and stopped heating is closed corresponding magnetic valve, water pump and heat pump set;
(4) Heating by Ground Source Heat Pump pattern
Fermentation vat 1 interior temperature is lower than when water temperature is lower than the ground heat exchanger return water temperature in 32 ℃ and the transfer hot water storage tank 7, and system is according to the Heating by Ground Source Heat Pump mode operation.Under this pattern, the first magnetic valve 14, the 5th magnetic valve 18 are opened, electric T-shaped valve 13 is communicated to the input terminus of heat pump low temperature side recycle pump 12 by the outlet of U-shaped ground heat exchanger 23, and the second heating cycle pump 11, heat pump low temperature side recycle pump 12 are opened, and the heat pump main frame is opened.The low temperature side of heat pump moves according to the first low-temperature heat source loop, and the high temperature side of heat pump main frame operates to the methane-generating pit heating according to the second heating loop.Temperature is higher than 37 ℃ in fermentation vat, and stopped heating is closed corresponding magnetic valve, water pump and heat pump set;
(5) sun power underground heat storage pattern
Fermentation vat 1 interior temperature is higher than when water temperature is higher than 70 ℃ in 35 ℃ and the transfer hot water storage tank 7, system is according to sun power underground heat storage mode operation, the first magnetic valve 14, the 7th magnetic valve 21 are opened, electric T-shaped valve 13 is communicated to transfer hot water storage tank the second water-in 7d by the outlet of U-shaped ground heat exchanger 23, and the first heating cycle pump 7 is opened; Under this pattern, can when the water temperature in the transfer hot water storage tank 7 is reduced to 50 ℃, stop the operation of this pattern with the transfer of heat in the transfer hot water storage tank 7 to underground storage by U-shaped ground heat exchanger 23, close corresponding valve and water pump.
The invention has the advantages that:
1) the present invention can prepare the thermograde of hot water according to solar energy collector, relation curve in conjunction with vaporizer inflow temperature and heat pump set COP, the solar energy-ground source heat pump coupled system is divided into plurality of operating modes (especially solar heat pump pattern and the division of solar energy-heat pump series model being come), can maximizedly utilize low-grade sun power and Geothermal energy, improve significantly the heating efficiency of heat pump set and system, had obvious energy-saving effect.
2) for methane-generating pit this characteristics that need to heat throughout the year, proposed sun power and earth source heat pump are effectively combined, can give full play to the advantage of the two, remedied mutual shortcoming.By the complementation of the energy, well solved unstable and this two large problems of earth source heat pump long-time running Efficiency Decreasing of solar heating.This system for a long time efficient stable be the marsh gas fermentation pool heating.Has long-term economy and environment benefit.
Description of drawings
Fig. 1 is that solar energy-ground source heat pump heat pump coupled biogas pool heating system of the present invention forms structural representation.
Number in the figure: 1 is fermentation vat, 2 is coil heat exchanger, 3 is the heat pump main frame, 4: heat pump main frame vaporizer, 5 is the heat pump main condenser, 6 is the solar full-glass vacuum tube heat collector, 7 are the transfer hot water storage tank, 7a is transfer hot water storage tank the first water outlet, 7b is transfer accumulation of heat hydrophone the first water-in, 7c is transfer hot water storage tank the second water outlet, 7d is transfer hot water storage tank the second water-in, 8 is the level pressure expansion drum, 9 is the heat collector hot water recycle pump, 10,11,12 for being respectively the first heating cycle pump, the second heating cycle pump and heat pump low temperature side recycle pump, 13 is electric T-shaped valve, 14,15,16,17,18,20 and 21 are respectively the first magnetic valve, the second magnetic valve, the 3rd magnetic valve, the 4th magnetic valve, the 5th magnetic valve, the 6th magnetic valve and the 7th magnetic valve, 19,22 are respectively the first vacuum breaker and the second vacuum breaker, 23 is U-shaped ground heat exchanger, 24,25,26 and 27 are respectively the first temperature sensor, the second temperature sensor, three-temperature sensor and the 4th temperature sensor.
Embodiment
Further specify by reference to the accompanying drawings the present invention below by embodiment.
Embodiment 1: be 69.3m for a certain useful volume
3The fully mixing fermentation vat, the present invention has selected four to amount to 26m
2The solar full-glass vacuum tube heat collecting module of collector area, and four heat collecting modules are composed in series a solar full-glass vacuum tube heat collector; The transfer hot water storage tank is cylindrical enclosed bearing insulated water box, and the design bearing capacity is 0.6MPa, actual pressure-bearing 0.2Mpa, and insulation requires to reach the temperature drop of water in the water tank less than 1 ℃/day; Used heat pump set is ground source/water source heat pump units, and its nominal heating capacity is 18.3kW; U-shaped ground heat exchanger is composed in parallel by the single U-shaped pipe of the PE of 5 φ 25*2.8, and the vertical depth of underground pipe is 100m; Coil heat exchanger is that the PERT pipe coiling of φ 25*2.8 forms, and is arranged at the bottom of the wall and pond of fermentation vat, and the coil pipe overall length is 200m.
As shown in Figure 1, solar energy-ground source heat pump heat pump coupled biogas pool heating system of the present invention is comprised of solar thermal collection system, heat pump, methane-generating pit heating system, sun power underground heat storage system.Wherein:
Solar thermal collection system comprises solar full-glass vacuum tube heat collector 6, transfer hot water storage tank 7 and heat collector hot water recycle pump 9, turn hot water storage tank 7 and have two pairs of intake-outlets, be respectively the first water outlet 7a, the first water-in 7b, the second water outlet 7c, the second water-in 7d, the symmetrical top and the bottom that are distributed in water tank, the bottom of water tank is connected with level pressure expansion drum 8, the swell increment after being used for the level pressure of system and bearing Water in Water Tanks being heated.Transfer hot water storage tank the first water outlet 7a links to each other with the input terminus of heat collector hot water recycle pump 9, the output terminal of heat collector hot water recycle pump 9 connects the input terminus of solar full-glass vacuum tube heat collector 6, the output terminal of solar full-glass vacuum tube heat collector 6 connects transfer hot water storage tank the first water-in 7b, consists of the solar energy heating loop; Heat collector hot water recycle pump 9 enters solar full-glass vacuum tube heat collector 6 from the water that transfer hot water storage tank 7 bottoms the first water outlet 7a draws the transfer hot water storage tank 7, got back in the transfer hot water storage tank 7 by transfer hot water storage tank 7 tops the first water-in 7b after this is heated, so constantly circulation prepares high-temperature-hot-water and is stored in the transfer hot water storage tank 7 again.
Heat pump comprises heat pump main frame 3, U-shaped ground heat exchanger 23, transfer hot water storage tank 7 and heat pump low temperature side recycle pump 12.Heat pump of the present invention has two alternative low-temperature heat source loops, is respectively: the first low-temperature heat source loop and the second low-temperature heat source loop, wherein:
The first low-temperature heat source loop: the water outlet of heat pump main frame vaporizer 4 is connected with the water-in of U-shaped ground heat exchanger 23 by the second vacuum breaker 22, the first magnetic valve 14 successively, the water outlet of U-shaped ground heat exchanger 23 connects the input terminus of heat pump low temperature side recycle pump 12 by electric T-shaped valve 13, the output terminal of heat pump low temperature side recycle pump 12 links to each other with the water-in of heat pump main frame vaporizer 4, so consists of one take the heat pump first low-temperature heat source loop of Geothermal energy as the basis.
The second low-temperature heat source loop: heat pump main frame vaporizer 4 → the second vacuum breaker 22 → the second magnetic valves 15 → transfer hot water storage tank 7 → electric T-shaped valve 13 → heat pump low temperature side recycle pump 12 → heat pump main frame vaporizer 4 so consists of one take the heat pump second low-temperature heat source loop of sun power as the basis.
Methane-generating pit heating system of the present invention comprises fermentation vat 1, coil heat exchanger 2, heat pump main condenser 5, transfer hot water storage tank 7, the first heating cycle pump 10 and the second heating cycle pump 11.Wherein, coil heat exchanger 2 is arranged in the fermentation vat 1, and described methane-generating pit heating system has three alternative heating loops, is respectively:
The first heating loop: transfer hot water storage tank the second water outlet 7c connects the input terminus of the first heating cycle pump 10, the output terminal of the first heating cycle pump 10 is by the water-in of the 3rd magnetic valve 16 terminal pad tube heat-exchanger 2, the water outlet of coil heat exchanger 2 connects transfer hot water storage tank the second water-in 7d by the 4th magnetic valve 17, consists of the first heating loop;
The second heating loop: the water outlet of heat pump main condenser 5 is by the water-in of the first vacuum breaker 19 terminal pad tube heat-exchanger 2, the water outlet of coil heat exchanger 2 connects the input terminus of the second heating cycle pump 11 by the 5th magnetic valve 18, the output terminal of the second heating cycle pump 11 connects the water-in of heat pump main condenser 5, consists of the second heating loop;
The 3rd heating loop: transfer hot water storage tank 7 second water outlet 7c connect the input terminus of the second heating ring pump 11 by the 6th magnetic valve 20, the output terminal of the second heating cycle pump 11 connects the water-in of heat pump main condenser 5, the water-in of the water outlet terminal pad tube heat-exchanger 2 of heat pump main condenser 5, the water outlet of coil heat exchanger 2 consists of the 3rd heating loop by the second water-in 7d of the 4th magnetic valve 17 connection transfer hot water storage tanks 7.
Coil heat exchanger 2 adopts the PERT pipe of φ 25*2.8, coil space 200mm, and coil lengths is 200m.In order to strengthen heating agent in the coil heat exchanger 2 and the heat transmission of fermented feed liquid, whipping appts need to be installed in fermentation vat.In the present invention, the methane-generating pit heating system add temperature-heat-source can come 6 preparations of free solar energy collector be stored in the transfer hot water storage tank 7 high-temperature-hot-water or by the high-temperature-hot-water of heat pump main frame 3 preparations.
Sun power underground heat storage system mainly is that the exhaustless part heat of heating system is stored into underground by U-shaped ground heat exchanger 23 when summer in spring and autumn, intensity of solar radiation was better, recover the soil moisture with this, guarantee for a long time operation of efficient stable of earth source heat pump.It comprises the first heating cycle pump 10, U-shaped ground heat exchanger 23, transfer hot water storage tank 7, the 7th magnetic valve 21, the first magnetic valve 14 and electric T-shaped valve 13, transfer hot water storage tank the second water outlet 7c links to each other with the input terminus of the first heating cycle pump 10, the output terminal of the first heating cycle pump 10 is successively by the 7th magnetic valve 21, the first magnetic valve 14 links to each other with the water-in of U-shaped ground heat exchanger 23, the water outlet of U-shaped ground heat exchanger 23 is received transfer hot water storage tank the second water-in 7d through electric T-shaped valve 13, forms the sun power underground heat storage loop of a closure.
The header end of described solar full-glass vacuum tube heat collector 6 is equipped with the first temperature sensor 24, the second temperature sensor 25 is equipped with at transfer hot water storage tank 7 middle parts, fermentation vat 1 middle part one side is equipped with three-temperature sensor 26, on the U-shaped ground heat exchanger 23 1 side backwater mains the 4th temperature sensor 27 is housed.
Described transfer hot water storage tank 7 bottoms are connected with level pressure expansion drum 8 and blow-off pipe.
The progress control method of solar energy-ground source heat pump heat pump coupled biogas pool heating system, there are five kinds of operational modes in described system: be respectively: sun power direct heating pattern; Solar energy-ground source heat pump series connection heating mode; The solar heat pump heating mode; The independent heating mode of earth source heat pump and sun power underground heat storage pattern; The operation control of described system is divided into the operation control of three sub-systems: solar thermal collection system operation control, methane-generating pit heating system operation control and the control of sun power underground heat storage system.Wherein:
1) solar thermal collection system operation control
The present invention adopts the operation of temperature differential method control solar thermal collection system, end at the header of the solar full-glass vacuum tube heat collector 6 of every group of series connection is installed DS18B20 first temperature sensor 24, and the middle part of transfer hot water storage tank 7 fills a DS18B20 the second temperature sensor 25.If the temperature difference of DS18B20 the first temperature sensor 24 and DS18B20 the second temperature sensor 25 is during greater than 6 ℃, heat collector heating cycle pump 9 is opened, and the water in the transfer hot water storage tank 7 is constantly heated by heat collector.When the two the temperature difference during less than 3 ℃ heat collector heating cycle pump 9 stop.
2) methane-generating pit heating system operation control
According to the temperature in the transfer hot water storage tank and local underground pipe return water temperature, the methane-generating pit heating system can be respectively according to sun power direct heating pattern, solar energy-ground source heat pump series connection heating mode, solar heat pump heating mode, the operation of Heating by Ground Source Heat Pump pattern various modes.The progress control method of each pattern is as follows:
(1) sun power direct heating pattern
When fermentation vat 1 interior temperature is lower than 32 ℃, and when water temperature is higher than 50 ℃ in the transfer hot water storage tank 7, system is according to sun power direct heating mode operation, the 3rd magnetic valve 16, the 4th magnetic valve 17 are opened, remaining closed electromagnetic valve, the first heating cycle pump 10 is opened, and all the other equipment (comprising water pump, heat pump etc.) are closed.By the first heating loop, that is: current pass through the second water outlet 7c of transfer hot water storage tank 7 successively, the first heating cycle pump 10, the 3rd magnetic valve 16, coil heat exchanger 2, the 4th magnetic valve 17, the second water-in 7d finally by transfer hot water storage tank 7 gets back to transfer hot water storage tank 7, so that temperature reaches design requirements in the fermentation vat, water temperature is lower than 45 ℃ in 37 ℃ or the transfer hot water storage tank 7 when temperature in the fermentation vat is higher than, and this pattern is out of service;
(2) solar energy-ground source heat pump series connection heating mode
Temperature is lower than 32 ℃ in fermentation vat, and water temperature is lower than 45 ℃ and when being higher than 30 ℃ in the transfer hot water storage tank 7, system is according to the operation of solar energy-ground source heat pump series connection heating mode, this moment the first magnetic valve 14, the 4th magnetic valve 17, the 6th magnetic valve 20 is opened, all the other closed electromagnetic valves, electric T-shaped valve 13 guiding connect U-shaped ground heat exchanger 23 1 sides, the second heating cycle pump 11, heat pump low temperature side recycle pump 12 is opened, heat pump main frame 3 is opened, the low temperature side of heat pump main frame moves according to foregoing the first low-temperature heat source loop, and the high temperature side of heat pump main frame then operates to the methane-generating pit heating according to foregoing the second heating loop; Temperature is higher than 37 ℃ in fermentation vat, and stopped heating is closed corresponding magnetic valve, water pump and heat pump set;
(3) solar heat pump heating mode
Temperature is lower than 32 ℃ in fermentation vat, and water temperature is lower than 30 ℃ and above Ground during the buried tube heat exchanger return water temperature in the transfer hot water storage tank 7, system moves according to the solar heat pump heating mode, that is: the low-temperature water heating of sun power preparation uses as the low level heat energy of heat pump, preparing high-temperature-hot-water by heat pump set is the marsh gas fermentation pool heating, the second magnetic valve 15, the 5th magnetic valve 18 is opened, electric T-shaped valve 13 is communicated to the input terminus of heat pump low temperature side recycle pump 12 by transfer hot water storage tank the second water-in 7d, the second heating cycle pump 11, heat pump low temperature side recycle pump 12 is opened, and the heat pump main frame is opened; The low temperature side of heat pump main frame moves according to foregoing the second low-temperature heat source loop, and the high temperature side of heat pump main frame then operates to the methane-generating pit heating according to foregoing the first heating loop.Temperature is higher than 37 ℃ in fermentation vat, and stopped heating is closed corresponding magnetic valve, water pump and heat pump set;
(4) Heating by Ground Source Heat Pump pattern
Temperature is lower than when water temperature is lower than the ground heat exchanger return water temperature in 32 ℃ and the transfer hot water storage tank 7 in the fermentation vat, and system is according to the Heating by Ground Source Heat Pump mode operation.Under this pattern, the first magnetic valve 14, the 5th magnetic valve 18 are opened, electric T-shaped valve 13 is communicated to the input terminus of heat pump low temperature side recycle pump 12 by the outlet of U-shaped ground heat exchanger 23, and the second heating cycle pump 11, heat pump low temperature side recycle pump 12 are opened, and the heat pump main frame is opened.The low temperature side of heat pump moves according to foregoing the first low-temperature heat source loop, and the high temperature side of heat pump main frame then operates to the methane-generating pit heating according to foregoing the first heating loop.Temperature is higher than 37 ℃ in fermentation vat, and stopped heating is closed corresponding magnetic valve, water pump and heat pump set.
(5) sun power underground heat storage master mode
Temperature is higher than when water temperature is higher than 70 ℃ in 35 ℃ and the transfer hot water storage tank 7 in the fermentation vat, and system is according to sun power underground heat storage mode operation.At this moment, the first magnetic valve 14, the 7th magnetic valve 21 are opened, and electric T-shaped valve 13 is communicated to transfer hot water storage tank the second water-in 7d by the outlet of U-shaped ground heat exchanger 23, and the first heating cycle pump 7 is opened; Under this pattern, can when the water temperature in the transfer hot water storage tank 7 is reduced to 50 ℃, stop the operation of this pattern with the transfer of heat in the transfer hot water storage tank 7 to underground storage by U-shaped ground heat exchanger 23, close corresponding valve and water pump.