CN201652992U - Hybrid ground-source heat pump system - Google Patents

Abstract

The utility model discloses a hybrid ground-source heat pump system, which comprises a building inner loop and an auxiliary heat dissipating device loop, wherein the building inner loop consists of a heat exchanger, a four way valve, a compressor and a vertical tube. The auxiliary heat dissipating device loop consists of a cooling tower. Wherein the building inner loop and the auxiliary heat dissipating device loop are separated to be the loop with independent cycle, and are coupled through a plate heat exchanger, heat is exchanged between the building inner loop and the auxiliary heat dissipating device loop through the plate heat exchanger. For southern regions which have much larger heat discharge capacity in summer than heat absorption capacity in winter, compared with a single ground-source heat pump, the system has the advantages of saving the investment and decreasing the running cost and the like. For areas which have smaller proportion of heating period to cooling period, the hybrid system which unites the cooling tower and the ground-source heat pump is more competitive than the single water source heat pump system and the single ground source heat pump system.

Description

Hybrid earth-source hot-pump system

Technical field

The utility model relates to the novel energy technology of building environmental protection and energy saving, especially relates to a kind of hybrid earth-source hot-pump system that utilizes earth source heat pump and cooling tower, heat supply heating that is used to build and central air-conditioning.

Background technology

Building energy consumption is main for the warm air conditioning energy consumption of thermal recovery, and therefore, the emphasis of building energy conservation should be placed on heating and the cooling energy consumption.Soil source heat pump is to be the heat pump of thermal source with the earth, and improve Lowlevel thermal energy in the earth by heat pump winter, to building heating, stores cold simultaneously, in order to summer grade; Transfer of heat in will building by heat pump summer is lowered the temperature to building to underground, stores heat simultaneously, in order to winter usefulness.

But also there are some problems in present soil source heat pump in application:

(1) place capacity problem: because the thermal conductivity factor of soil is little, the area that buries the ground heat exchanger can be bigger, and each department are because the restriction of actual conditions relies on the soil source heat pump air conditioner system possibly can't meet design requirement separately.

(2) initial investment is bigger: the initial cost of soil source heat pump not only comprises the ground upper pipeline that traditional air-conditioning system is required and the investment of equipment, also comprises outdoor drilling well, buries the ground coil pipe, buries that the ground coil pipe lays and investment such as grouting.

(3) the recovery problem of soil moisture field: along with the prolongation of the independent heat supply of earth-source hot-pump system or cooling running time, the temperature field in the soil can not get recovering for a long time, and system can't satisfy the hot and cold burden requirement of building.Water source heat pump technology also is subjected to some restrictions owing to recharge its popularization of problem of problem and system's long-time running stability; And there are mistaken ideas in some owners, HVAC designer to the understanding of ground source heat pump technology, and promptly earth source heat pump can only carry out heat exchange with soil, cooling tower can not occur, and it is just not energy-conservation cooling tower to occur.

Particularly with regard to the warm summer in present winter was thermally distinguished, ground source heat pump technology did not also have more application example, trace it to its cause, and the one, initial cost is too high, and floor space is big.The 2nd, southern air-conditioning is based on refrigeration, and it is bigger to bury the required area of ground heat exchanger, than the north, and the initial investment height of system.The 3rd, the general inclined to one side employing electricity of air-conditioning freezes, and does not have the pressure of environmental protection policy aspect.How thermally distinguishing to hold water in the warm summer in winter uses ground source heat pump technology to become the hot issue that academia and engineering circle need solve.

Summary of the invention:

The purpose of this utility model is to propose the warm summer in a kind of suitable winter and thermally distinguishes the technical scheme of the hybrid earth-source hot-pump system that uses earth source heat pump of holding water, and as the heat supply heating of building and the novel energy of central air-conditioning, reaches environmental protection and purpose of energy saving.

For realizing the purpose of this utility model, the spy proposes a kind of hybrid earth-source hot-pump system, and this system comprises building inner ring road and auxiliary radiating device loop, and described building inner ring road is made of heat exchanger, four way valve, compressor and perpendicularly buried pipe; Described auxiliary radiating device loop is made of cooling tower;

Wherein, described building inner ring road and auxiliary radiating device loop are split up into the loop of independent loops, and the two is coupled by plate type heat exchanger, can carry out heat exchange by the plate type heat exchanger coupling.

Described auxiliary radiating device loop is with the cooling device of cooling tower as auxiliary radiating device, described auxiliary radiating device comprises the cooling tower starting drive, when the leaving water temperature of the heat exchanger of described building inner ring road reached 25 ℃～35 ℃, described cooling tower starting drive started described cooling tower.

The type selecting of described auxiliary radiating device satisfies following formula:

$Q_{\mathrm{Rej}}=\frac{Q_{\mathrm{Tot}.\mathrm{Rej}}-Q_{\mathrm{Loop}.\mathrm{Rej}}}{2\×3600\×\mathrm{Hours}}$

Q _RejDesign thermal discharge (kW) for auxiliary radiating device

Q _Tot.RejBe design cooling moon heat radiation total amount (kJ)

Q _Loop.RejFor arrive the design cooling moon heat dissipation capacity (kJ) of soil by heat exchangers

Hours is the hourage of the design cooling moon.

The discharge V of described cooling tower ₁(m ³/ h) satisfy following formula:

$V_1=\frac{Q_{\mathrm{Rej}}}{\mathrm{\ρc\ΔT}}.$

Advantage of the present utility model:

For the southern area that summer, heat exhaust recepted the caloric much larger than winter, in some commercialization or the application of public building soil source heat pump system, utilization auxiliary radiating device (traditional open type cooling tower adds board-like heat exchanger), compare with independent soil source heat pump, hybrid system has reducing investment outlay and reduces advantages such as operating cost.

Heat supply cycle and the more little zone of refrigeration cycle ratio, cooling tower is more competitive than single water source heat pump system and single earth-source hot-pump system with the hybrid system of earth source heat pump associating.

Description of drawings

Fig. 1 is hybrid earth-source hot-pump system overall structure schematic diagram;

Fig. 2 is the plate type heat exchanger schematic diagram.

The specific embodiment

At the thermal balance question that has soil aspect the earth source heat pump use all the time, the own characteristic of soil source heat pump and its best scope of application is arranged, the i.e. cold and suitable area of summer in winter cooling and heating load of Xia Redong.In the hot area since its summer cooling load load greater than Winter heat supply, make the heat that heat pump summer absorbs from soil greater than winter to the heat of underground discharging, cause the soil moisture to raise gradually, the condensation temperature of earth source heat pump unit improves when causing use summer, causes refrigerating capacity to reduce, and the wasted work rate rises, coefficient of refrigerating performance COP reduces, generally speaking, the soil moisture raises 1 ℃, can make the energy consumption of producing same cold increase by 3～4%.Therefore, keep that the earth source heat pump underground penstock heat exchanger system is inhaled, the heat extraction balance is that earth source heat pump is normal, the reliable assurance of efficient operation.For perpendicularly buried pipe, general buried depth is mostly at 30～100m, if adopt single earth-source hot-pump system finally can cause buried coil pipe exchange capability of heat to descend, and then need more jumbo geothermal heat exchanger meeting design requirement, but the initial cost of system is rapidly increased.According to actual measurement and theoretical calculating, the suggestion summer in winter is not more than 20% for well to the suction heat balance difference of soil.If it is bigger that thermal balance differs, just should take auxiliary cooling (or heating) mode, this system that has auxiliary cooling (or heating) is called hybrid earth-source hot-pump system.

Hybrid earth-source hot-pump system of the present utility model as shown in Figure 1, this system utilizes cooling tower as the earth source heat pump auxiliary radiating device.As shown in the figure: system of the present utility model mainly contains two loops and forms, and is respectively building inner ring road and heat abstractor loop.Building inner ring road that constitutes by heat exchanger, four way valve, compressor and perpendicularly buried pipe and the heat abstractor loop that constitutes by cooling tower separately, by the plate type heat exchanger coupling, the building inner ring road can be independent of the cooling tower operation.

The typical method of operation of auxiliary radiating device is: when the leaving water temperature of geothermal heat exchanger reached a definite upper limit (usually at 25 ℃～35 ℃), the heat abstractor that starts the cooling tower formation was shared the load of geothermal heat exchanger.

The computational methods of hybrid earth source heat pump comprise:

1) type selecting of auxiliary radiating device

No matter outdoor conditions is how, auxiliary radiating device can be discharged into heat in the surrounding environment, can be on the basis of the design cooling moon radiating requirements type selecting, that is,

$Q_{\mathrm{Rej}}=\frac{Q_{\mathrm{Tot}.\mathrm{Rej}}-Q_{\mathrm{Loop}.\mathrm{Rej}}}{2\×3600\×\mathrm{Hours}}$

Q in the formula _RejDesign thermal discharge (kW) for auxiliary radiating device

Q _Tot.RejBe design cooling moon heat radiation total amount (kJ)

Q _Loop.RejFor arrive the design cooling moon heat dissipation capacity (kJ) of soil by heat exchangers

Hours is the hourage of the design cooling moon; 31d * 24h/d (generally by July or August)

The outdoor conditions of hypothesis design month 50% hourage is not too abominable in this selection method, and therefore, the heat-sinking capability of heat abstractor has very big surplus.

The supply and return water temperature difference of cooling tower is Δ T, and the discharge of calculating by the cooling tower side is V ₁(m ³/ h).

$V_1=\frac{Q_{\mathrm{Rej}}}{\mathrm{\ρc\ΔT}}$

2) underground buried tube heat exchange amount

Figure 2 shows that the schematic diagram of plate type heat exchanger, among the figure, T ₁Expression underground buried tube leaving water temperature (℃), T ₁' expression enter the source pump temperature (℃), T ₂Expression cooling tower supply water temperature (℃), T ₂' expression cooling tower return water temperature (℃).

Plate type heat exchanger is considered to best indirect heat exchanger, it has following characteristics: good heat conductivility, sealing factor is low, compactness and malleable heat exchange area or path combination, can satisfy bigger flow thereby terminal temperature difference is little, can make of erosion-resisting material, and sheet is thin, in light weight removable the maintenance.Under design conditions, the Inlet and outlet water temperature difference of source pump is Δ T.

The design water flow of computation cycles water side is V ₂(m ³/ h):

$V_2=\frac{Q_R}{\mathrm{\ρc\Δ}{T}^{\′}}$

Q _R(kw) be recirculated water side heat exchange amount, the temperature difference of approaching of choosing underground buried tube water outlet and cooling tower backwater is 1.7 ℃, calculates: T ₁=T ₂'+1.7

Check in the leaving water temperature of source pump by the source pump sample, be designated as T _g(℃)

Calculate underground buried tube heat exchange amount:

Q _g＝ρcV ₂(T _g-T ₁)Q _g

3) selection of cooling water pump:

Flow=V ₁, lift: H=H _z+ h _t

In the formula: H _zThe sparge pipe of expression cooling tower own is to the discrepancy in elevation of water pond, mh _tThe drag losses of expression pipeline, flow, lift were respectively got 10% affluence amount when m chose water pump.

(1) thermally distinguish in the warm summer in winter, use the auxiliary earth source heat pump heat radiation of cooling tower to help to reduce the initial cost of association system, the increase of the refrigeration duty ratio of bearing along with cooling tower, the initial cost of association system is fewer and feweri.

(2) from the operating cost aspect, the load proportion that cooling tower accounts for is big more, and annual operating cost is high more, and when cooling tower bore for 50% when load separately with burying the ground heat exchanger, annual operating cost has increased by 8.8% than source heat pump system independently.

(3) optimization of association system depends on desired value and the service life of investment payback time.For desired value and the service life of different investment payback times, distributing rationally of system will be done concrete analysis.

Claims (4)

1. a hybrid earth-source hot-pump system is characterized in that, this system comprises building inner ring road and auxiliary radiating device loop, and described building inner ring road is made of heat exchanger, four way valve, compressor and perpendicularly buried pipe; Described auxiliary radiating device loop is made of cooling tower;

Wherein, described building inner ring road and auxiliary radiating device loop are split up into the loop of independent loops, and the two is coupled by plate type heat exchanger.

2. according to the hybrid earth-source hot-pump system of claim 1, it is characterized in that, described auxiliary radiating device comprises the cooling tower starting drive, and when the leaving water temperature of the heat exchanger of described building inner ring road reached 25 ℃～35 ℃, described cooling tower starting drive started described cooling tower.

3. according to the hybrid earth-source hot-pump system of claim 1, it is characterized in that the type selecting of described auxiliary radiating device satisfies following formula:

$Q_{\mathrm{Rej}}=\frac{Q_{\mathrm{Tot}.\mathrm{Rej}}-Q_{\mathrm{Loop}.\mathrm{Rej}}}{2\×3600\×\mathrm{Hours}}$

Q _RejDesign thermal discharge (kW) for auxiliary radiating device

Q _Tot.RejBe design cooling moon heat radiation total amount (kJ)

Q _Loop.RejFor arrive the design cooling moon heat dissipation capacity (kJ) of soil by heat exchangers

Hours is the hourage of the design cooling moon.

4. according to the hybrid earth-source hot-pump system of claim 1, it is characterized in that,, it is characterized in that the discharge V of described cooling tower according to the hybrid earth-source hot-pump system of claim 1 ₁(m ³/ h) satisfy following formula:

$V_1=\frac{Q_{\mathrm{Rej}}}{\mathrm{\ρc\ΔT}}$

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