CN103884064B - A kind of irradiation space refrigerator as auxiliary cold source and heat transfer modeling method - Google Patents

Abstract

The invention discloses a kind of irradiation space refrigerator as auxiliary cold source and heat transfer modeling method, comprise a metal framework, described metal framework is provided with one or more radiation refrigerator module, it is two galvanized steel plain sheets that described radiation refrigerator module comprises, and forms the gap of Cooling Water flowing between two galvanized steel plain sheets; The two ends of two described galvanized steel plain sheet length directions are communicated with cooling water water knockout drum and cooling water water collector respectively, and described cooling water water knockout drum is communicated with cooling water inlet, and cooling water water collector is communicated with coolant outlet; Width two ends connect.This kind of irradiation space refrigerator can under meteorological optimum with other stable low-temperature receiver use connected in series or in parallel of water source heat pump system, jointly for heat pump provides cold.

Description

A kind of irradiation space refrigerator as auxiliary cold source and heat transfer modeling method

Technical field

What the present invention relates to is a kind of irradiation space refrigerator as auxiliary cold source and heat transfer modeling method, belongs to Building Environment and Equipment Engineering, building thermal environments and Refrigeration Engineering technical field.

Background technology

In recent years, utilize the ground source heat pump technology of reproducible shallow layer geothermal energy to obtain in building air conditioning field to develop rapidly.Closed-loop ground source heat pump technology is wherein flowed in the underground buried tube closed by circulation fluid, protects valuable groundwater resources while realizing high efficient heat exchanging.Current many international bodies and government are all using applying closed-loop ground source heat pump technology as economize energy, minimizing CO ₂the important means of discharge and environmental protect problem.Closed-loop ground source heat pump technology utilizes the huge and metastable characteristic of underground temperature of the earth thermal capacity, by closed loop ground heat exchanger summer to soil release heat, winter from soil absorption heat, is realized building cold and heat supply by heat pump.

But, in applying, encounter the obstacle in building load balance with the closed-loop ground source heat pump technology that energy-conserving and environment-protective are famous.China is across warm temperate zone and subtropical zone, and large amount of building especially commercial building belongs to refrigeration duty and to be dominant type building, and namely its annual refrigeration duty sum is greater than annual thermic load sum.When using closed-loop ground source heat pump technology in refrigeration duty is dominant type building, single ground heat exchanger is greater than the caloric receptivity of winter from soil as the Cooling and Heat Source of heat pump by making the heat exhaust of summer to soil, waste heat can be made after longtime running to gather in ground heat exchanger surrounding soil, cause the rising of the soil moisture, and then heat pump inflow temperature in summer is raised, cause whole system operational efficiency to reduce, even make thrashing.To deal with problems and the key of clearing away the obstacles is annual load balance that ground heat exchanger is born to use other auxiliary cooling modes to get rid of the unbalanced refrigeration duty of building.

The auxiliary cooling mode of existing closed-loop ground source heat pump technology concentrates on and uses cooling tower in air, get rid of unbalanced building refrigeration duty.But in actual motion, some buildings are not suitable for using cooling tower because the conditions such as residing location, appearance requirement, water saving requirement, noise control limit, the closed-loop ground source heat pump technology of energy-conserving and environment-protective to be used in these refrigeration dutys are dominant type building, more suitable, more energy-conservation auxiliary cooling mode must be sought.

Space nocturnal radiation refrigeration phenomenon has benefited from the infrared electromagnetic radiation heat exchange between Earth surface plane and space (close to absolute zero).The atmosphere of earth surface for the infra-red radiation of wavelength between 8 ~ 13 μm close to completely through.Therefore, at the high object of this wave-length coverage inner surface emissivity, can effectively utilize night space as free low-temperature receiver to discharge self heat.As a kind of effective, cheap passive type nature type of cooling, space nocturnal radiation Refrigeration Technique obtains all circles researcher and more and more pays close attention to;

Research about irradiation space refrigerator is few in number, and is all applied to the passive type refrigeration of building.Form adopts common flat type solar heat collector operation at night to double as a radiation refrigerator, and its refrigerating efficiency is very low; Another kind of form is that the baroque refrigerator of specialized designs carries out long-wave radiation at night, its refrigerating efficiency increase but processing and fabricating costly.Owing to there is intrinsic limitation, existing irradiation space refrigerator is not suitable as the stable low-temperature receiver of the active refrigeration system of building.First, the refrigeration usefulness of irradiation space refrigerator is not mated with building refrigeration duty, and it is afternoon that the peak value of building refrigeration duty appears at summer, however the refrigeration performance of irradiation space refrigerator in the winter time night best.Secondly, the refrigerating efficiency of irradiation space refrigerator is comparatively large by the impact of outdoor air relative humidity, sky cloud thickness and air purity, refrigerating capacity less stable.Again, the energy-flux density of irradiation space refrigerator is not high, and the refrigeration work consumption of unit are is little, therefore needs to take larger building roof area.

Summary of the invention

In order to overcome the limitation that prior art exists, the effective means that passive type irradiation space freezes is utilized to be the auxiliary cold source that it can be used as active refrigeration system.Therefore, the present invention is directed to " water source heat pump system " this most frequently used building active refrigeration form, devise that radiation refrigeration efficiency within the scope of source pump cooling water temperature is higher, processing is simple and manufacture the cheap a kind of irradiation space refrigerator as auxiliary cold source of maintenance cost.This kind of irradiation space refrigerator can under meteorological optimum with other stable low-temperature receiver use connected in series or in parallel of water source heat pump system, jointly for heat pump provides cold.The conveniently designing and calculating of this kind of irradiation space refrigerator, the present invention proposes modeling method of conducting heat accordingly.

The technical solution used in the present invention is as follows:

As an irradiation space refrigerator for auxiliary cold source, comprise a framework, described framework is provided with one or more radiation refrigerator module, described radiation refrigerator module comprises two metallic plates for heat conduction; And between two metallic plates, form the gap of Cooling Water flowing; The two ends of two described metallic plate length directions are communicated with cooling water water knockout drum and cooling water water collector respectively, and metallic plate width two ends directly connect; And described cooling water water knockout drum is communicated with cooling water inlet, cooling water water collector is communicated with coolant outlet.

Described metallic plate is galvanized steel plain sheet; The employing of metallic plate width two ends presses without rivet and adds adhesive connection.

When described radiation refrigerator module is polylith, be connected in parallel between radiation refrigerator module.

Described framework is metal framework, between the face that metal framework parallels with radiation refrigerator module, be provided with insulation material.

Spacing between two described galvanized steel plain sheets is 5mm.

Described galvanized steel plain sheet is provided with the pitting of regular distribution, cross arrangement, spacing 5cm.

In order to strengthen further night infrared emissivity and daytime solar radiation reflectivity, at the outer coating white titanium dioxide of the galvanized steel plain sheet being positioned at face, upper strata.

The best mounting means of described irradiation space refrigerator is laid on building roof.

The heat transfer modeling method of the heat dissipation capacity of described irradiation space refrigerator, comprises the following steps:

Step (1) starts;

Step (2) obtains outdoor weather data, comprises air themperature T _a, relative air humidity RH, atmospheric pressure P, wind speed u _a, space infrared intensity R _is, use interpolation calculation to go out the thermal conductivity factor k of air _a, kinematic viscosity ν _awith Prandtl number Pr _a, and calculate space equivalent temperature T according to Si Difen-graceful law of Bohr thatch _s;

σ=5.67 × 10 in formula ^-8w/ (m ²k ⁴) be Si Difen-graceful constant of Bohr thatch;

Step (3) obtains the structural parameters of irradiation space refrigerator, comprises length L and the width W of irradiation space refrigerator, adopt thickness δ and the thermal conductivity factor k of galvanized steel plain sheet _s, and the infrared emittance ε of coating of titanium dioxide outside galvanized steel plain sheet;

Step (4) obtains the cooling water flow m of irradiation space refrigerator;

Step (5) calculates the cooling water flow velocity u in cooler according to continuity equation _f,

u _f＝m/(L·W)；

Step (6) obtains the cooling water inlet water temperature T of irradiation space radiator _fi;

Step (7) supposes that the coolant outlet water temperature of irradiation space refrigerator is T _foa;

Step (8) arranges iterations IT=0;

Step (9) calculates irradiation space radiator inner cooling water mean temperature T _m,

T _m=0.5*(T _fi+T _foa)；

Step (10) uses interpolation calculation water temperature T _mthe physical property of corresponding cooling water, comprises the specific heat capacity c of cooling water _p, thermal conductivity factor k _f, kinematic viscosity ν _fwith Prandtl number Pr _f;

Step (11) calculates the convection transfer rate h between irradiation space refrigerator upper strata galvanized steel plain sheet outside wall surface and surrounding air ₁;

$h_1=0.664\·k_a\·{\left(\frac{u_a}{v_a\·L}\right)}^{1/2}\text{\·}{{\mathrm{Pr}}_a}^{1/3}$

Step (12) calculates the convection transfer rate h between irradiation space refrigerator upper strata galvanized steel plain sheet internal face and cooling water ₂;

$h_2=0.664\·k_f\·{\left(\frac{u_f}{v_f\·L}\right)}^{1/2}\·{{\mathrm{Pr}}_f}^{1/3}$

Step (13) calculates the outside wall surface temperature T of irradiation space refrigerator upper strata galvanized steel plain sheet _w1;

Can biquadratic equation be obtained according to energy balance:

$\mathrm{\ϵ}\·\mathrm{\σ}\·T_{\mathrm{wl}}^4+(h_1+\frac{h_2}{1+\frac{\mathrm{\δ}}{k_2}{\·h}_2})\·T_{\mathrm{wl}}=\mathrm{\ϵ}\·\mathrm{\σ}\·{T_s}^4+h_1{\·T}_a+(h_2-\frac{\frac{\mathrm{\δ}}{k_s}\·{h_2}^2}{1+\frac{\mathrm{\δ}}{k_s}\·h_2})\·T_m$

Solve the outside wall surface temperature T that can obtain irradiation space refrigerator upper strata galvanized steel plain sheet _w1:

$T_{\mathrm{wl}}=\frac{-k+\sqrt{k^2-4l}}{2}$

Being calculated as follows of k and l in above formula:

$k={[\frac{4r}{3}{\left(\frac{q^2+\sqrt{q^4-\frac{256}{27}{r}^3}}{2}\right)}^{-\frac{1}{3}}+{\left(\frac{q^2+\sqrt{q^4-\frac{256}{27}{r}^3}}{2}\right)}^{\frac{1}{3}}]}^{\frac{1}{2}},l=\frac{k^3-q}{2k}$

In formula $q=\frac{B}{A},r=-\frac{C}{A}$

$A=\mathrm{\ϵ}\·\mathrm{\σ},B=h_1+\frac{h_2}{1+\frac{\mathrm{\δ}}{k_s}\·h_2},C=\mathrm{\ϵ}\·\mathrm{\σ}\·{T_s}^4+h_1\·T_a+(h_2-\frac{\frac{\mathrm{\δ}}{k_s}\·{h_2}^2}{1+\frac{\mathrm{\δ}}{k_s}\·h_2})\·T_m$

Step (14) calculates the coolant outlet water temperature T of irradiation space refrigerator _fo;

$T_{\mathrm{fo}}=\frac{\frac{\mathrm{\δ}}{k_s}\·h_2\·T_m+T_{\mathrm{wl}}}{1+\frac{\mathrm{\δ}}{k_s}\·h_2}+\frac{T_{\mathrm{fi}}-\frac{\frac{\mathrm{\δ}}{k_s}\·h_2\·T_m+T_{\mathrm{wl}}}{1+\frac{\mathrm{\δ}}{k_s}\·h_2}}{\exp \left(\frac{L\·W\·h_2}{m\·c_p}\right)}$

Step (15) judges | T _fo-T _foa| whether be less than permissible value; If so, the operational factor (coolant outlet water temperature and radiation refrigeration amount) of irradiation space refrigerator is then exported, out of service; If not, then Tfoa=0.5*(Tfo+Tfoa is reseted); IT=IT+1; Turn back to step (9), continue circulation.

Symbol implication is as follows:

C _p: the specific heat capacity (Jk of cooling water _g ^-1k ^-1);

H ₁: the convection transfer rate (Wm between irradiation space refrigerator upper strata outside wall surface and surrounding air ^-2k ^-1);

H ₂: the convection transfer rate (Wm between irradiation space refrigerator upper strata internal face and cooling water ^-2k ^-1);

IT: iterations;

K _a: the thermal conductivity factor (Wm of air ^-1k ^-1);

K _f: the thermal conductivity factor (Wm of cooling water ^-1k ^-1);

K _s: the thermal conductivity factor (Wm of galvanized steel plain sheet ^-1k ^-1);

L: the length (m) of irradiation space refrigerator;

M: the cooling water flow (kg/s) of irradiation space refrigerator;

P: atmospheric pressure (Pa);

Pr _a: the Prandtl number of air;

Pr _f: the Prandtl number of cooling water;

RH: relative air humidity (%);

R _is: space infrared intensity (Wm ^-2);

T _a: air themperature (K);

T _fi: the cooling water inlet water temperature (K) of irradiation space radiator;

T _fo: the coolant outlet water temperature (K) of irradiation space refrigerator;

T _foa: the coolant outlet water temperature default (K) of irradiation space refrigerator;

T _m: irradiation space radiator inner cooling water mean temperature (K);

T _s: space equivalent temperature (K);

T _w1: the outside wall surface temperature (K) of irradiation space refrigerator upper strata galvanized steel plain sheet;

U _a: outdoor wind speed (ms ^-1);

U _f: the cooling water flow velocity (ms in irradiation space radiator ^-1);

W: the width (m) of irradiation space refrigerator;

δ: the thickness (m) of galvanized steel plain sheet;

ε: the infrared emittance of coating of titanium dioxide outside galvanized steel plain sheet;

The graceful constant of σ: Si Difen-Bohr thatch;

ν _a: the kinematic viscosity (m of air ²s ^-1);

ν _f: the kinematic viscosity (m of cooling water ²s ^-1);

Beneficial effect of the present invention is as follows:

Because galvanized steel plain sheet is cheap and easy to get, thermal conductivity factor is large, and has higher emissivity at infra red radiation band, and the radiation refrigerator module therefore in the present invention selects thickness to be that the galvanized steel plain sheet of 1mm makes.

In order to increase the relative area of dissipation of cooling water, the present invention makes cooling water flow between the space that two galvanized steel plain sheets that spacing is 5mm are formed.The water collecting and diversifying device that two ends, steel plate length direction are 40mm by external diameter is connected with cooling water pipeline, and the employing of width two ends presses without rivet and adds adhesive connection.

Some depression points that galvanized steel plain sheet distributes strengthen the heat transfer between cooling water and steel plate by reinforcement flow disturbance.

In order to strengthen the irradiation space refrigeration at night further and reduce the solar gain on daytime, the present invention considers after economy at the outer coating white titanium dioxide (the infrared emittance ε ≈ 0.94 of 8 ~ 13 μm) of upper strata galvanized steel plain sheet.

In order to adapt to different radiation refrigeration amounts and mounting condition, each radiation refrigerator block length can adjust between 1 ~ 3m, and width can adjust between 0.5 ~ 2m.Coating steel pipe is adopted to be connected in parallel between each radiation refrigerator module, according to water force determination coating steel pipe caliber.

According to the characteristic of radiation heat transfer space thermal resistance, space thermal resistance when radiating surface is parallel with space is minimum, and radiation heat transfer performance is best.Therefore, the best mounting means of irradiation space refrigerator is laid on building roof.

The performance of irradiation space refrigerator raises with the increase of its internal cooling water flow velocity, but the excessive energy consumption that can increase again water circulating pump of flow velocity, therefore there is the cooling water economic velocity of irradiation space refrigerator.Compare through simulation, under general operating mode, this economic velocity is about 0.5kg/s.

Accompanying drawing explanation

Fig. 1 irradiation space refrigerator structural map;

Fig. 2 is the B-B view of Fig. 1;

Fig. 3 is the A-A view of Fig. 1;

Fig. 4 irradiation space refrigerator analog computation flow chart;

Fig. 5 be coupled passive type irradiation space refrigeration buried pipe ground-source heat pump system schematic diagram;

In figure: 1-1 cooling water water knockout drum, 1-2 cooling water water collector, 1-3 insulation material, 1-4 metal framework, 1-5 galvanized steel plain sheet, 1-6 depression points, 1-7 cooling water inlet, 1-8 coolant outlet, 1 irradiation space refrigerator, 2 reflux tanks, 3 irradiation space kind of refrigeration cycle water pumps, 4 heat exchangers, 5 valve I, 5 ' valve II, 6 ground heat exchangers, 7 underground pipe water circulating pumps, 8 source pump heat exchanger I, 9 expansion mechanism I, 9 ' expansion mechanism II, 10 source pump heat exchanger II, 11 user side water circulating pumps, 12 compressors, 13 desuperheaters, 14 domestic hot-water's casees, 15 building grounds, 16 hot water for life equipment, 17 air-conditioned rooms, 18 building roofs, 19 temperature sensors, 20 flow sensors.

Detailed description of the invention

According to analysis of Heat Transfer result, need reinforcement material emissivity as much as possible at the irradiation space refrigerator of source pump cooling water temperature operated within range, and increase cooling water with extraneous relative heat exchange area to realize higher refrigeration performance as far as possible.Compared with baroque radiation cooling device, simple slab construction has suitable radiation refrigeration ability, and more easily processing, installation and maintenance, there is higher cost performance.Therefore, the invention discloses a kind of simply constructed radiation refrigerator module, as Figure 1-3, one or more refrigerator module can be selected in engineering to bear actual required radiation refrigeration amount, comprise a metal framework 1-4, described metal framework 1-4 is at least provided with a radiation refrigerator module, and it is two galvanized steel plain sheet 1-5 that radiation refrigerator module comprises, and forms the gap of Cooling Water flowing between two galvanized steel plain sheet 1-5; The two ends of two described galvanized steel plain sheet 1-5 length directions are communicated with cooling water water knockout drum 1-1 and cooling water water collector 1-2 respectively, and described cooling water water knockout drum 1-1 is communicated with cooling water inlet 1-7, and cooling water water collector 1-2 is communicated with coolant outlet 1-8; The employing of width two ends presses without rivet and adds adhesive connection.Insulation material 1-3 is provided with between the face that galvanized steel plain sheet is parallel with metal framework.

Because galvanized steel plain sheet is cheap and easy to get, thermal conductivity factor is large, and has higher emissivity at infra red radiation band, and the radiation refrigerator module therefore in the present invention selects thickness to be that the galvanized steel plain sheet of 1mm makes.In order to increase the relative area of dissipation of cooling water, the present invention makes cooling water flow between the space that two galvanized steel plain sheets that spacing is 5mm are formed.The water collecting and diversifying device that two ends, steel plate length direction are 40mm by external diameter is connected with cooling water pipeline, and the employing of width two ends presses without rivet and adds adhesive connection.As shown in Figure 1, some depression points 1-6 that galvanized steel plain sheet distribute strengthen heat transfer between cooling water and steel plate by strengthening flow disturbance.

In order to strengthen the irradiation space refrigeration at night further and reduce the solar gain on daytime, the present invention considers after economy at the outer coating white titanium dioxide (the infrared emittance ε ≈ 0.94 of 8 ~ 13 μm) of upper strata galvanized steel plain sheet.

In order to adapt to different radiation refrigeration amounts and mounting condition, each radiation refrigerator block length can adjust between 1 ~ 3m, and width can adjust between 0.5 ~ 2m.Coating steel pipe is adopted to be connected in parallel between each radiation refrigerator module, according to water force determination coating steel pipe caliber.

According to the characteristic of radiation heat transfer space thermal resistance, space thermal resistance when radiating surface is parallel with space is minimum, and radiation heat transfer performance is best.Therefore, the best mounting means of irradiation space refrigerator is laid on building roof.

On the other hand, the performance of irradiation space refrigerator depends on the weather conditions such as cloud thickness, ceiling of clouds, dew-point temperature.For realizing Effec-tive Function, irradiation space refrigerator should be opened at sunny and partly cloudy and that dew-point temperature is low night as much as possible.If because uneven refrigeration duty is not got rid of by irradiation space radiator by the restrictions such as weather condition completely in the summer cooling phase, also underground pipe water circulating pump and radiation refrigerator water circulating pump can be opened the night in spring in the winter time after the heat supply phase, by its cooperation, under better weather condition, the waste heat gathered in soil is effectively drained into space.

The method for designing of the analytic solutions heat transfer model of irradiation space refrigerator is as follows:

Operationally, cooling water is flowed into by entrance irradiation space refrigerator, presss from both sides interflow and discharge waste heat mainly through the radiation heat transfer between refrigerator and space at galvanized steel plain sheet, flows out after reducing own temperature.According to analysis of heat transfer, irradiation space refrigerator runs under being adapted at sunny or partly cloudy night conditions.

After the accuracy considering computation model and practicality, the present invention establishes analytic solutions heat transfer model with the operational factor of simulation space radiation refrigerator under different operating mode on the basis of following several presupposition:

(1) because change of temperature field after stable operation is relatively slow, the heat transfer of irradiation space refrigerator can be considered steady-state process.

(2) due to the existence of heat-insulation layer, can think that heat radiation and a small amount of thermal convection current only occur in the upper surface of irradiation space refrigerator, ignore the heat transfer of other positions.

(3) the cooling-water duct thickness of irradiation space refrigerator inside is very little, and cooling water and heat can be thought and only propagate along water (flow) direction one dimension.

(4) the irradiation space refrigerator upper surface being coated with coating of titanium dioxide can be considered that infrared emittance is the grey body of 0.94.

(5) thermal diffusion coefficient due to galvanized steel plain sheet is large, and the upper surface of irradiation space refrigerator can be considered isothermal surface.

Based on above-mentioned assumed condition, the heat transfer expression formula of the heat output of cooling water space-ward radiation refrigerator upper surface, irradiation space refrigerator upper surface and the heat loss through convection amount of surrounding air, the heat loss through radiation amount between irradiation space refrigerator upper surface and space can be derived according to heat transfer basic theories.According to the heat balance of irradiation space refrigerator by each heat transfer expression formula simultaneous, the refrigerating capacity of irradiation space refrigerator and the analytic solutions of coolant outlet water temperature can be obtained.This analytic solutions heat transfer model can be used for simulation and the designing and calculating of irradiation space refrigerator, and its iterative method calculation process as shown in Figure 4, specifically comprises the following steps:

Step (1) starts;

Step (2) obtains outdoor weather data, comprises air themperature Ta, relative air humidity RH, atmospheric pressure P, wind speed u _a, space infrared intensity R _is, use interpolation calculation to go out the thermal conductivity factor k of air _a, kinematic viscosity ν _awith Prandtl number Pr _a, and calculate space equivalent temperature T according to Si Difen-graceful law of Bohr thatch _s,

σ=5.67 × 10 in formula ^-8w/ (m ²k ⁴) be Si Difen-graceful constant of Bohr thatch;

Step (3) obtains the structural parameters of irradiation space refrigerator, comprises length L and the width W of irradiation space refrigerator, adopt thickness δ and the thermal conductivity factor k of galvanized steel plain sheet _s, and the infrared emittance ε of coating of titanium dioxide outside galvanized steel plain sheet;

Step (4) obtains the cooling water flow m of irradiation space refrigerator;

Step (5) calculates the cooling water flow velocity u in irradiation space refrigerator according to continuity equation _f,

u _f＝m/(L·W)；

Step (6) obtains the cooling water inlet water temperature T of irradiation space refrigerator _fi;

Step (7) supposes that the coolant outlet water temperature of irradiation space refrigerator is T _foa;

Step (8) arranges iterations IT=0;

Step (9) calculates irradiation space refrigerator inner cooling water mean temperature T _m,

T _m=0.5*(T _fi+T _foa)；

Step (10) uses interpolation calculation water temperature T _mthe physical property of corresponding cooling water, comprises the specific heat capacity c of cooling water _p, thermal conductivity factor k _f, kinematic viscosity ν _fwith Prandtl number Pr _f;

Step (11) calculates the convection transfer rate h between irradiation space refrigerator upper strata galvanized steel plain sheet outside wall surface and surrounding air ₁;

$h_1=0.664\·k_a\·{\left(\frac{u_a}{v_a\·L}\right)}^{1/2}\text{\·}{{\mathrm{Pr}}_a}^{1/3}$

Step (12) calculates the convection transfer rate h between irradiation space refrigerator upper strata galvanized steel plain sheet internal face and cooling water ₂;

$h_2=0.664\·k_f\·{\left(\frac{u_f}{v_f\·L}\right)}^{1/2}\·{{\mathrm{Pr}}_f}^{1/3}$

Step (13) calculates the outside wall surface temperature T of irradiation space refrigerator upper strata galvanized steel plain sheet _w1;

Can biquadratic equation be obtained according to energy balance:

$\mathrm{\ϵ}\·\mathrm{\σ}\·T_{\mathrm{wl}}^4+(h_1+\frac{h_2}{1+\frac{\mathrm{\δ}}{k_2}{\·h}_2})\·T_{\mathrm{wl}}=\mathrm{\ϵ}\·\mathrm{\σ}\·{T_s}^4+h_1{\·T}_a+(h_2-\frac{\frac{\mathrm{\δ}}{k_s}\·{h_2}^2}{1+\frac{\mathrm{\δ}}{k_s}\·h_2})\·T_m$

Solve the outside wall surface temperature T that can obtain irradiation space refrigerator upper strata galvanized steel plain sheet _w1:

$T_{\mathrm{wl}}=\frac{-k+\sqrt{k^2-4l}}{2}$

Being calculated as follows of k and l in above formula:

$\begin{array}{c}k={[\frac{4r}{3}{\left(\frac{q^2+\sqrt{q^4-\frac{256}{27}{r}^3}}{2}\right)}^{-\frac{1}{3}}+{\left(\frac{q^2+\sqrt{q^4-\frac{256}{27}{r}^3}}{2}\right)}^{\frac{1}{3}}]}^{\frac{1}{2}},\end{array}jl=\frac{k^3-q}{2k}$

In formula, $q=\frac{B}{A},r=-\frac{C}{A}$

$A=\mathrm{\ϵ}\·\mathrm{\σ},B=h_1+\frac{h_2}{1+\frac{\mathrm{\δ}}{k_s}\·h_2},C=\mathrm{\ϵ}\·\mathrm{\σ}\·{T_s}^4+h_1\·T_a+(h_2-\frac{\frac{\mathrm{\δ}}{k_s}\·{h_2}^2}{1+\frac{\mathrm{\δ}}{k_s}\·h_2})\·T_m$

Step (14) calculates the coolant outlet water temperature T of irradiation space refrigerator _fo;

$T_{\mathrm{fo}}=\frac{\frac{\mathrm{\δ}}{k_s}\·h_2\·T_m+T_{\mathrm{wl}}}{1+\frac{\mathrm{\δ}}{k_s}\·h_2}+\frac{T_{\mathrm{fi}}-\frac{\frac{\mathrm{\δ}}{k_s}\·h_2\·T_m+T_{\mathrm{wl}}}{1+\frac{\mathrm{\δ}}{k_s}\·h_2}}{\exp \left(\frac{L\·W\·h_2}{m\·c_p}\right)}$

Step (15) judges | T _fo-T _foa| whether be less than permissible value; If so, the operational factor (coolant outlet water temperature and radiation refrigeration amount) of irradiation space refrigerator is then exported, out of service; If not, then Tfoa=0.5*(Tfo+Tfoa is reseted); IT=IT+1; Turn back to step (9), continue circulation.

Meaning of parameters is as follows:

C _pspecific heat capacity (the Jkg of cooling water ^-1k ^-1);

H ₁convection transfer rate (Wm between irradiation space refrigerator upper strata outside wall surface and surrounding air ^-2k ^-1);

H ₂convection transfer rate (Wm between irradiation space refrigerator upper strata internal face and cooling water ^-2k ^-1);

IT iterations;

K _athermal conductivity factor (the Wm of air ^-1k ^-1);

K _fthermal conductivity factor (the Wm of cooling water ^-1k ^-1);

K _sthermal conductivity factor (the Wm of galvanized steel plain sheet ^-1k ^-1);

The length (m) of L irradiation space refrigerator;

The cooling water flow (kg/s) of m irradiation space refrigerator;

P atmospheric pressure (Pa);

Pr _athe Prandtl number of air;

Pr _fthe Prandtl number of cooling water;

RH relative air humidity (%);

R _isspace infrared intensity (Wm ^-2);

T _aair themperature (K);

T _fithe cooling water inlet water temperature (K) of irradiation space radiator;

T _fothe coolant outlet water temperature (K) of irradiation space refrigerator;

T _foathe coolant outlet water temperature default (K) of irradiation space refrigerator;

T _mirradiation space radiator inner cooling water mean temperature (K);

T _sspace equivalent temperature (K);

T _w1the outside wall surface temperature (K) of irradiation space refrigerator upper strata galvanized steel plain sheet;

U _aoutdoor wind speed (ms ^-1);

U _fcooling water flow velocity (ms in irradiation space radiator ^-1);

The width (m) of W irradiation space refrigerator;

The thickness (m) of δ galvanized steel plain sheet;

The infrared emittance of coating of titanium dioxide outside ε galvanized steel plain sheet;

σ Si Difen-graceful constant of Bohr thatch;

ν _akinematic viscosity (the m of air ²s ^-1);

ν _fkinematic viscosity (the m of cooling water ²s ^-1).

The buried pipe ground-source heat pump system of the coupling irradiation space refrigeration utilizing irradiation space refrigerator to form

For realizing the target of the cold and hot balance of annual underground environment and energy saving of system optimization, the present invention adopts when designing the buried pipe ground-source heat pump system of coupling irradiation space refrigeration ground heat exchanger to bear refrigeration duty and to be dominant the hot and cold load of the type building balance whole year, adopts irradiation space refrigerator to bear remaining uneven refrigeration duty.

As shown in Figure 5, whole system comprise be arranged at building roof 18 irradiation space refrigerator 1, be arranged at the source pump in building and be embedded in building ground 15 under ground heat exchanger 6, and irradiation space refrigerator is coupled in buried pipe ground-source heat pump system, the connected mode of cooling water pipeline in system: the outlet of described irradiation space refrigerator 1 is communicated with the entrance of irradiation space refrigerator 1 after heat exchanger 4 through reflux tank 2 successively; The outlet of described ground heat exchanger 6 is communicated with the entrance of source pump heat exchanger I8 all the time after underground pipe water circulating pump; The outlet of source pump heat exchanger I8 is communicated with the entrance of heat exchanger 4 or the entrance of ground heat exchanger 6 respectively, and the pipeline be communicated with heat exchanger 4 entrance at source pump heat exchanger I8 is provided with the valve II5 ' opened that only freezes at night, the pipeline that source pump heat exchanger I8 is communicated with the entrance of ground heat exchanger 6 is provided with only at the valve I5 closed that freezes at night; Meanwhile, source pump heat exchanger I8 is communicated with desuperheater 13 with expansion mechanism I9, source pump heat exchanger II10, compressor 12 successively by refrigerant loop again.

In addition; In dotted line frame, single arrow represents the refrigerant flow direction of cooling operating mode source pump, and double-head arrow represents the refrigerant flow direction for thermal condition source pump.

At source pump heat exchanger II10, the refrigerant line that source pump heat exchanger I8 is communicated with is provided with and is also provided with the expansion structure II9 ' in parallel with expansion structure I9.Series circulation water pump 3, temperature sensor 19 on the outlet of irradiation space refrigerator 1 and the connecting pipe of plate type heat exchanger 4, plate type heat exchanger 4 and the entrance connecting pipeline of ground heat exchanger are in series with temperature sensor 19.

The outlet of ground heat exchanger and the entrance connecting line of source pump heat exchanger I8 are in series with underground pipe water circulating pump 7, temperature sensor 19.The outlet of source pump heat exchanger I8 and the entrance connecting pipe of heat exchanger are in series with temperature sensor 19, flow sensor 20, control valve I5; And the outlet of source pump heat exchanger I8 is communicated with the entrance of ground heat exchanger 6, the pipeline that it is communicated with is provided with control valve II5 '.Described desuperheater 13 is communicated with domestic hot-water's case 14.Described source pump heat exchanger II10 is connected on the circulating water line of user side, by cold-producing medium and user side recirculated water, the exchange heat in source pump heat exchanger II10 realizes Winter heat supply to air-conditioned room 17 and summer cooling, and user side circulating water line is provided with user side water circulating pump 11, temperature sensor 19, flow sensor 20.

Wherein the desuperheater of source pump can utilize the domestic hot-water needed for condensation heat extraction production building of cold-producing medium, makes a living to apply flexibly hot water facility 16 and provide domestic hot-water; Not only freely obtain domestic hot-water like this, the uneven degree of building cooling and heating load can also be reduced.Irradiation space refrigerator forms auxiliary radiating device with reflux tank together with plate type heat exchanger, connects and composes the whole cooling water loop of source pump with ground heat exchanger.

During Winter heat supply operating mode, irradiation space refrigerator 1 does not work, and valve I5 opens, and valve II5 ' closes; Source pump compressor 12 export high-temperature high-pressure refrigerant first in desuperheater to domestic hot-water's heat release, then the source pump heat exchanger II10 as condenser is entered, by heat medium water to conditioned space heat supply in building, the source pump heat exchanger I8 as evaporimeter is entered, by the recirculated water in ground heat exchanger from soil absorption heat after expansion mechanism II9 ';

When summer cooling operating mode is run daytime, irradiation space refrigerator 1 does not work, and now valve I5 opens, and valve II5 ' closes; Source pump compressor 12 export high-temperature high-pressure refrigerant first in desuperheater to domestic hot-water's heat release, then enter source pump heat exchanger I8 as condenser by the recirculated water in ground heat exchanger to soil release heat, with after after decompressor I9, enter source pump heat exchanger II10 as evaporimeter by chilled water to air-conditioned room in building 17 cooling;

When running irradiation space refrigerator 1 night, irradiation space refrigerator 1 works, valve I5 closes, valve II5 ' opens, irradiation space kind of refrigeration cycle water pump is opened, making cooling water flow through being installed on the irradiation space refrigerator 1 on roof, discharging uneven part building cooling load by radiation heat transfer space-ward; Irradiation space refrigerator out of service after sunrise on daytime, Open valve I5, valve-off II5 ', close irradiation space kind of refrigeration cycle water pump, make the cooling water in irradiation space refrigerator flow to reflux tank under gravity.

As whole system be the continuous service condition continuing cooling night time, the high-temperature cooling water that flowed out by source pump condenser flows into ground heat exchanger after first taking away partial heat via plate type heat exchanger by irradiation space refrigerator continues to soil heat release.As whole system be the intermittent duty condition stopping cooling night time, only underground pipe water circulating pump and radiation refrigerator water circulating pump cooperation, got rid of the heat gathered in soil by irradiation space refrigerator.

Irradiation space refrigerator 1 out of service after sunrise on daytime, Open valve I5, valve-off II5 ', close irradiation space kind of refrigeration cycle water pump, make the cooling water in irradiation space refrigerator flow to reflux tank under gravity.Period out of service by day, irradiation space radiator inside be anhydrous state to reduce the thermal capacity of radiator, increase the efficiently radiates heat amount at radiator night.

The performance of irradiation space refrigerator raises with the increase of its internal cooling water flow velocity, but the excessive energy consumption that can increase again water circulating pump of flow velocity, therefore there is the cooling water economic velocity of irradiation space refrigerator.Compare through simulation, under general operating mode, this economic velocity is about 0.5kg/s.On the other hand, the performance of irradiation space refrigerator depends on the weather conditions such as cloud thickness, ceiling of clouds, dew-point temperature.For realizing Effec-tive Function, irradiation space refrigerator should be opened at sunny and partly cloudy and that dew-point temperature is low night as much as possible.If because uneven refrigeration duty is not got rid of by irradiation space radiator by the restrictions such as weather condition completely in the summer cooling phase, also underground pipe water circulating pump and radiation refrigerator water circulating pump can be opened the night in spring in the winter time after the heat supply phase, by its cooperation, under better weather condition, the waste heat gathered in soil is effectively drained into space.

Heat exchange amount calibration equipment

As shown in Figure 5, system has installed temperature and flow sensor, be respectively used to metering user side heat exchange amount, irradiation space refrigerator heat exchange amount and ground heat exchanger heat exchange amount, the practical operation situation that the buried pipe ground-source heat pump system freezed to control the passive type irradiation space that has been coupled is dominant in type building in refrigeration duty.

For verifying the whether cold and hot balance of annual underground environment, the heat exchange amount calibration equipment of Operation system setting comprises the thermal resistance temperature sensor measuring ground heat exchanger gateway water temperature, and measures the turbine flow transducer of circulating water flow.The signal of these sensor collections is admitted in microcomputer after being changed by A/D and calculates cold and hot amount.When inlet water temperature is lower than outlet water temperature, the heat adding up winter and extract from soil; When inlet water temperature is higher than outlet water temperature, add up the heat into entering soil summer.After running 1 year by comparison system, the size of (through a confession hot season and a confession cold season) cold and hot amount accumulated number judges the cold and hot balance of underground environment.

Claims (9)

1. the heat transfer modeling method as the irradiation space refrigerator of auxiliary cold source, it is characterized in that: refrigerator comprises a framework, described framework is provided with one or more radiation refrigerator module, and described radiation refrigerator module comprises two metallic plates for heat conduction; And between two metallic plates, form the gap of Cooling Water flowing; The two ends of two described metallic plate length directions are communicated with cooling water water knockout drum and cooling water water collector respectively, and described cooling water water knockout drum is communicated with cooling water inlet, and cooling water water collector is communicated with coolant outlet; Width two ends connect;

Modeling method is as follows:

Step (1) starts;

Step (2) obtains outdoor weather data, comprises air themperature T _a, relative air humidity RH, atmospheric pressure P, wind speed u _a, space infrared intensity R _is, use interpolation calculation to go out the thermal conductivity factor k of air _a, kinematic viscosity ν _awith Prandtl number Pr _a, and calculate space equivalent temperature T according to Si Difen-graceful law of Bohr thatch _s;

σ=5.67 × 10 in formula ^-8w/ (m ²k ⁴) be Si Difen-graceful constant of Bohr thatch;

Step (3) obtains the structural parameters of irradiation space refrigerator, comprises length L and the width W of irradiation space refrigerator, adopt thickness δ and the thermal conductivity factor k of galvanized steel plain sheet _s, and the infrared emittance ε of coating of titanium dioxide outside galvanized steel plain sheet;

Step (4) obtains the cooling water flow m of irradiation space refrigerator;

Step (5) calculates the cooling water flow velocity u in cooler according to continuity equation _f,

u _f＝m/(L·W)；

Step (6) obtains the cooling water inlet water temperature T of irradiation space radiator _fi;

Step (7) supposes that the coolant outlet water temperature of irradiation space refrigerator is T _foa;

Step (8) arranges iterations IT=0;

Step (9) calculates irradiation space radiator inner cooling water mean temperature T _m,

T _m＝0.5*(T _fi+T _foa)；

Step (10) uses interpolation calculation water temperature T _mthe physical property of corresponding cooling water, comprises the specific heat capacity c of cooling water _p, thermal conductivity factor k _f, kinematic viscosity ν _fwith Prandtl number Pr _f;

Step (11) calculates the convection transfer rate h between irradiation space refrigerator upper strata galvanized steel plain sheet outside wall surface and surrounding air ₁;

Step (12) calculates the convection transfer rate h between irradiation space refrigerator upper strata galvanized steel plain sheet internal face and cooling water ₂;

Step (13) calculates the outside wall surface temperature T of irradiation space refrigerator upper strata galvanized steel plain sheet _w1;

Step (14) calculates the coolant outlet water temperature T of irradiation space refrigerator _fo;

Step (15) judges | T _fo-T _foa| whether be less than permissible value; If so, the operational factor of irradiation space refrigerator is then exported, out of service; If not, then Tfoa=0.5* (Tfo+Tfoa) is reseted; IT=IT+1; Turn back to step (9), continue circulation;

Described operational factor is coolant outlet water temperature and radiation refrigeration amount.

2. the heat transfer modeling method of irradiation space refrigerator as claimed in claim 1, is characterized in that: described width two ends employing presses without rivet and adds adhesive connection.

3. the heat transfer modeling method of irradiation space refrigerator as claimed in claim 1, is characterized in that: when described radiation refrigerator module is polylith, be connected in parallel between radiation refrigerator module.

4. the heat transfer modeling method of irradiation space refrigerator as claimed in claim 1, is characterized in that: between the face that metal framework parallels with radiation refrigerator module, be provided with insulation material.

5. the heat transfer modeling method of irradiation space refrigerator as claimed in claim 1, it is characterized in that: described metallic plate is galvanized steel plain sheet, the spacing between two described galvanized steel plain sheets is 5mm.

6. the heat transfer modeling method of irradiation space refrigerator as claimed in claim 5, is characterized in that: the pitting being provided with regular distribution on described galvanized steel plain sheet.

7. the heat transfer modeling method of irradiation space refrigerator as claimed in claim 5, is characterized in that: at the outer coating white titanium dioxide of the galvanized steel plain sheet being positioned at face, upper strata.

8. the heat transfer modeling method of irradiation space refrigerator as claimed in claim 1, is characterized in that: the best mounting means of described irradiation space refrigerator is laid on building roof.

9. the heat transfer modeling method of irradiation space refrigerator as claimed in claim 8, is characterized in that, as follows:

The detailed process of described step 13 is as follows:

Can biquadratic equation be obtained according to energy balance:

Solve the outside wall surface temperature T that can obtain irradiation space refrigerator upper strata galvanized steel plain sheet _w1:

$T_{w1}=\frac{-k+\sqrt{k^2-4l}}{2}$

In above formula: