CN1291195C - Refrigerating circulation and heat pump type hot water supply device - Google Patents

Abstract

To provide an environmentally-friendly heat pump water heater capable of assuring a high reliability by sufficiently holding oil film on a compressor sliding part and also capable of saving energy and providing a high efficiency in a heat pump water heater using carbon dioxide refrigerant (CO2). In this heat pump water heater using carbon dioxide refrigerator, either one type of poly [alpha]-olefin or paraffin mineral oil or naphthene mineral oil or alkyl benzene which show the non-compatibility with the carbon dioxide refrigerant or a mixed oil is used as a refrigerator oil. Thus the wear of a compressor can be suppressed, a leak current can be reduced, and a performance can be increased.

Description

Kind of refrigeration cycle and heat-pump water heater

Technical field

The present invention relates to adopt the kind of refrigeration cycle and the heat-pump water heater of carbon dioxide coolant.

Background technology

The cold-producing medium of existing kind of refrigeration cycle extensively adopts CFC (chlorine fluorohydrocarbon (Network ロ ロ Off Le オ ロ カ one ボ Application)), HCFC (hydrogenated chloride fluorine is for hydrocarbon (Ha イ De ロ Network ロ ロ Off Le オ ロ カ one ボ Application)); but from the viewpoint of protection ozone layer, with its abolish or minimizing.

Cold-producing medium as an alternative, its main flow is the HFC that does not damage the ozone layer (hydrogenation fluorine (Ha イ De ロ Off Le オ ロ カ one ボ Application)) cold-producing medium not chloride in the molecule, specifically, HFC134a (1 with thermodynamic behaviour close with CFC12 (difluoromethane (ジ Network ロ ロ ジ Off Le オ ロ メ Application)), 1,1, the 2-HFC-134a) is used for refrigerator or air conditioning for automobiles, substitute the mix refrigerant of the HFC series of HCFC22, promptly R410A (HFC32/125:50/50 weight %) or R407C (HFC32/125/134a:23/25/52 weight %) etc. are used for room air conditioner or combined air conditioner.

Yet,,, HFC also is tending towards restriction from preventing the viewpoint of global warming though HFC does not damage the ozone layer.

In recent years, from preserve our planet environment or noninflammability, hypotoxicity aspect, as the carbon dioxide (CO of natural cold-producing medium ₂) attracted attention.As adaptable product, once considered electric motor car air-conditioning, cold district heater unit and hot-water supply device etc.

The earth environment problem requires to save more the energy, high efficiency, with the hot-water supply device is that example describes, the hot-water supply device of employing carbon dioxide heat-pump formula is compared its advantage with the main flow mode coal gas formula of general home-use hot-water supply device be that running expense can reduce by 1/5 approximately, and efficiency factor (COP:Coefficient of Performance) can realize the high efficiency more than 3.0.For example: in heat-pump water heater during application of aforementioned HFC cold-producing medium, because the thermal physical characteristic of cold-producing medium, the highlyest can only supply with about 60 ℃ hot water, obtain higher temperature just needs the very compressor of high-output power.On the contrary, when adopting carbon dioxide coolant, its advantage is because the thermal physical characteristic of cold-producing medium can be exported about 90 ℃ hot water.

On the other hand, refrigerator oil is used on the closed type electromotive compressor, brings into play effects such as its lubricated portion is lubricated, sealing, cooling.Adopt the compressor of carbon dioxide coolant to be in high temperature, high pressure (about 10MPa) condition, so the service condition of refrigerator oil is harsh, therefore the reliability aspect of collateral security compressor requires the refrigerator oil can corresponding lubricity, especially can correspondingly save the energy, high efficiency.

As the kind of refrigeration cycle that adopts carbon dioxide and the refrigerator oil of compressor, the main employing has artificial oils such as the polyglycols oil of intermiscibility and polyol ester with cold-producing medium.

Specifically, open the 2001-66004 communique Japanese kokai publication hei 10-46169 communique, spy, the spy opens the 2001-73945 communique, and the special kinetic viscosity that discloses in the 2001-153476 communique when selecting at least a formation in polyglycols oil and the polyvinylether and 100 ℃ of opening surpasses 5mm ²The refrigerator oil constituent of/s, and the kind of refrigeration cycle, compressor etc. that adopt these refrigerator oil constituents, open 2000-273477 communique, spy the spy and open that 2000-273479 communique, spy are opened the 2000-345183 communique, the spy opens and discloses the refrigerator oil constituent that adopts polyol ester in the 2001-19987 communique.

Yet, on electrically-operated sealed compressor, also require performance, so polyglycols oil can't satisfy the specification value 10 that surpasses as the specific insulation of electric insulation oil because its molecular structure determines its electrical insulation capability very low as electric insulation oil ¹³Ω cm.Thereby be short-circuited between the sealing terminal of worrying to install, especially get an electric shock owing to dielectric constant or the higher leakage current that causes of dielectric loss tangent in order to provide external power source to compressor electric motor.

On the other hand, because its intermiscibility to carbon dioxide coolant of polyol ester is too high, the dissolving viscosity in the compressor declines to a great extent, on high-tension side sealing property is bad, cause compression efficiency to descend, the oil that flows out to kind of refrigeration cycle increases etc., may cause heat exchanger effectiveness to descend.

For the foregoing reasons, in heat-pump water heater, preferably carbon dioxide is shown that non-intermiscibility and the outstanding hydrocarbon ils of electrical insulating property are used as refrigerator oil.Little about adopting to the dissolubility of carbon dioxide, perhaps adopt the compressor of the non-refrigerator oil that mixes, be disclosed in the spy and open in the 2000-110725 communique, but, because its viscosity index (VI) of alkylbenzene is less, cause the viscosity of the low-temp. portion of kind of refrigeration cycle to increase, to the recirculating oil quantity minimizing of compressor.Thereby the danger of the insufficient lubrication that causes the compressor sliding part is arranged.Fluorocarbon oil is because the price height is unrealistic.

Summary of the invention

The present invention is in view of the above-mentioned problems and proposes, and purpose provides and can show that to carbon dioxide coolant the refrigerator oil of non-intermiscibility guarantees high reliability and can realize saving kind of refrigeration cycle and the heat-pump water heater energy and high efficiency, the love environment by adopting.

Kind of refrigeration cycle of the present invention and heat-pump water heater, its kind of refrigeration cycle is provided with: suck and the heat absorption heat exchanger of the aforementioned carbon dioxide coolant that the compressor of compression arbon dioxide cold-producing medium, the heat release that flows into the aforementioned carbon dioxide coolant of discharging from this compressor are depressurized aforementioned pressure reducer with heat exchanger, the pressure reducer that will reduce pressure from the aforementioned carbon dioxide coolant that this heat exchanger flows out and inflow; It is characterized in that,, adopt carbon dioxide coolant is shown the poly-alpha-olefin of non-intermiscibility or any oil or the miscella in alkanes mineral oil or cycloalkane mineral oil or the alkylbenzene as the refrigerator oil of compressor.

Another feature of the present invention is, adopts with aforementioned carbon dioxide coolant as its refrigerator oil to show that non-intermiscibility, kinetic viscosity are 2～15mm 100 ℃ the time ²The scope of/s and the viscosity index (VI) of aforementioned refrigerator oil surpass 100 any oil or miscella.

And then feature of the present invention is that the heat absorption refrigerant flow path of heat exchanger, its inflow entrance are positioned at the top, flow export places the below.

As described herein, has the compressor of passing through, the heat release heat exchanger that will carry out heat release from the cold-producing medium that aforementioned compressor is discharged, the pressure reducer that will reduce pressure from the cold-producing medium that heat exchanger flows out, and the kind of refrigeration cycle that circulates with heat exchanger of the heat absorption that makes the cold-producing medium that in pressure reducer, is depressurized absorb heat, and possess in the hot-water supply device of this kind of refrigeration cycle, refrigerator oil as compressor, by adopting the hydrocarbon ils that carbon dioxide coolant is shown non-intermiscibility, on the sliding part of compressor, can keep sufficient oil film, thereby, owing to prevent abrasion, keep sealing, so can improve compression efficiency.

As refrigerator oil, constitute by the hydrocarbon ils that carbon dioxide is shown non-intermiscibility, be exactly any oil or these the miscella in poly-alpha-olefin or alkanes mineral oil or cycloalkane mineral oil or the alkylbenzene specifically.Consider the delay of refrigerator oil on the kind of refrigeration cycle low-temp. portion, should guarantee easily preferably that viscosity index (VI) to the recirculating oil quantity of compressor surpasses the oil kind more than 100.As other carbon dioxide is shown the compound of non-intermiscibility, also have fluorocarbon oil (PFPE (パ one Off Le オ ロ Port リ エ one テ Le)) or silicone oil etc., yet, owing to cost an arm and a leg, the low of inferior quality reason of lubricity and impracticable.

The relevant refrigerator oil viscosity that is used in the hot-water supply device of the present invention, because the permeability of carbon dioxide is bigger, so for the consideration of sealing, should be preferably than the corresponding oily high slightly viscosity grade of fluorine Lyons class cold-producing medium.Specifically, in the swinging coolant compressor, the preferred 2～8mm of 100 ℃ viscosity ²/ s, the preferred 7～15mm of 100 ℃ viscosity under the situation of scroll compressor ²The scope of/s.Kinetic viscosity in the time of 100 ℃ can't obtain sufficient compressor wear resistance below it the time, can not guarantee sufficient seal, thereby causes compression efficiency to reduce.In addition, the kinetic viscosity in the time of 100 ℃ is more than it the time, because the increase of viscous drag, mechanical loss can produce compressor efficiency again and reduce, viscosity strengthens the problem that causes the recirculating oil quantity to compressor to reduce.In the present invention, also no problem fully even in aforementioned refrigerator oil, add antioxidant, acid reaction base conditioning agent, defoamer, metal inerting agent etc.

Description of drawings

Fig. 1 is the skeleton diagram of the hot-water supply device of explanation embodiments of the invention.

Fig. 2 is the longitudinal sectional view of the hot-water supply device unit of embodiments of the invention.

Fig. 3 is the cutaway view of the closed type electromotive compressor of explanation embodiments of the invention.

The specific embodiment

Below, root a tree name embodiment at length introduces the present invention.In the present embodiment, recorded and narrated and adopted the heat-pump water heater of carbon dioxide, yet be not limited only to this, also be applicable on the kind of refrigeration cycle of electric motor car air-conditioning and cold district heating equipment etc.

Fig. 1 represents the basic block diagram of the heat-pump water heater that adopts in the present embodiment.Be divided into kind of refrigeration cycle that carbon dioxide coolant circulates and the circulation that the water of supplying with is heated.

At first introduce kind of refrigeration cycle.Be housed in the closed type electromotive compressor 1 in closed container etc., the refrigerant gas (carbon dioxide coolant) of low temperature, low pressure is compressed, export the refrigerant gas of high temperature, high pressure again, deliver to water refrigerant heat exchanger 2 (heat release heat exchanger).Be sent to the refrigerant gas in the water refrigerant heat exchanger 2, its heat carries out the sensible heat exchange with the water at low temperature that is supplied to.Then,, become low temperature, low pressure, deliver to heat exchanger 4 (heat absorption heat exchanger) by pressure reducer 3.Enter into the cold-producing medium of heat exchanger 4,, discharge cold air through fan 5 from absorbing heat and evaporation on every side.

The low temperature that comes out from heat exchanger 4, the refrigerant gas of low pressure are drawn onto the compressor 1 once more, form the mechanism that carries out identical circulation repeatedly.Because carbon dioxide coolant becomes overcritical circulation, the high-pressure side postcritical can be set high-pressure arbitrarily, therefore can obtain the high-temperature water near 100 ℃ at an easy rate.

Next, introduction adds the hot water circulation.At first, the water at low temperature that feed water inlet 6 provides is delivered in the water refrigerant heat exchanger 2, obtained heat from cold-producing medium and become hot water, once delivering in the hot-water storage case 7, supply with hot water from hot water outlet 8.At this moment, the water that is supplied to also can be mixed into the trip temperature adjusting with the hot water of directly sending here from water refrigerant heat exchanger 2 and use.And except supplying with water, water refrigerant heat exchanger 2 also can will heat in order to the hot water in the hot-water storage case 7 of insulation, and not expression also can be used for burning water for bathing etc. among the figure.

In heat-pump water heater, the mode that two kinds of hot-water supplies are arranged, utilize night electricity to start heat pump cycle, with the storage hot water mode of hot-water storage in hot-water storage case 7 of using in the family one day, all start heat pump cycle with each use hot water, only provide the moment of the hot water of aequum to supply with the hot water mode.

Even the latter's mode, the auxiliary hot water container 7 that also need before hot water supply, hot water be stored.Be main flow generally to store the hot water mode, yet, still there is such problem: owing to limited the use amount of hot water, so consider the problem that hot water is used up or need jumbo hot-water storage case etc., the hot-water storage case can't be accommodated in the heat pump cycle unit, must establish the hot-water storage box unit in addition, thereby, increased space or the like has been set.

To this, the problem in the moment way of supplying water is the compressor of essential high-output power, owing to be to turn round at any time to carry out the supply of hot water, uses up so needn't worry hot water.As an example, Fig. 2 represents the easy longitudinal sectional view of the hot-water supply device unit of moment supply hot water mode, as long as its advantage is: because the auxiliary hot water container 7 of low capacity, so the hot-water storage case can be housed in the heat pump cycle unit, thereby realize being provided with the save spaceization in place.In addition, reduce significantly the duration of runs owing to comparing, so have the advantage of saving the energy concurrently with storage hot water mode.

The closed type electromotive compressor of hot-water supply device is based on swinging and vortex isometric(al) formula compressor.As the example of compressing mechanism, Fig. 3 represents the longitudinal sectional view of Rotary Compressor.During the single stage compress mode, as carbon dioxide coolant, when the high-pressure side became 10MPa, the surface pressing of compressing mechanism was very high, the oil film thickness attenuation.Thereby reliability decrease, differential pressure cause the low problem of compression efficiency more greatly, so, represent the twin-stage compress mode here.

Compressor is accommodated its compression unit and motor 10 in the closed container 9, stores refrigerator oil 11 in the closed container bottom.And, the hermetic terminal 12 that external power is provided is set on aforementioned motor 10.

Compression unit is to turn round at the axle 13 that itself and motor 10 directly links, and its be contained in prejudicially that a part of rolling 14A, 14B and oily 15A, 15B inwall on the axle 13 carries out that line contacts and bonding state under carry out rotating.The valve that will separate low-pressure chamber and hyperbaric chamber is inserted in the opening that forms on oily 15A, the 15B inwall, moves back and forth, and presses to and roll 14A, 14B by being located at no illustrated spring on the one end.Low pressure refrigerant gas by first suction line 16 is inhaled into is compressed owing to roll the eccentric motion of 14A, presses in the middle of becoming by first discharge pipe 17 to be discharged from.This be discharged from the middle of the refrigerant gas of pressing, be sucked into by second suction line 18 again be compressed owing to roll the eccentric motion of 15A, be discharged to water refrigerant heat exchanger 2 by second discharge pipe 19 as the refrigerant gas of high pressure.Because valve is that line contacts the friction that produces with rolling between 14A, the 14B, so its surface pressing is very big.Refrigerator oil 11 is drawn up by the centrifugal pump that is arranged on the gyroaxis, through oilhole 20, provides lubricating oil to each sliding part of compressor.

(embodiment 1～5)

In embodiment 1～5, adopt the former hotter water feeding mechanism to carry out the real machine test of running in 2160 hours.The hot-water supply device that turns round in the thermostatic chamber of 20 ℃ of conditions in summer, it is 60 ℃ that the temperature of supplying with hot water is set at the high temperature storage hot water conditions.In an embodiment, will show that the following compound of non-intermiscibility charges in the compressor to carbon dioxide coolant.Compd E is the thing that compd A and B are mixed with 50/50 weight %.

A) the viscosity 3.59mm of 100 ℃ of poly-alpha-olefins ²/ s

B) the viscosity 4.56mm of 100 ℃ in alkanes mineral oil ²/ s

C) the viscosity 4.25mm of 100 ℃ in cycloalkane mineral oil ²/ s

D) the viscosity 3.78mm of 100 ℃ of alkylbenzenes ²/ s

E) poly-alpha-olefin+alkanes mineral oil (50/50 weight %)

100 ℃ viscosity 4.12mm ²/ s

In the comparative example 1～2, will show that the following compound of intermiscibility charges in the compressor, carry out the real machine test identical with embodiment 1 to carbon dioxide coolant.Because carbon dioxide coolant is had intermiscibility, so compare with embodiment 1～5, viscosity strengthens.

F) be subjected to the viscosity 10.2mm of 100 ℃ of resistance type polyol esters ²/ s

(pentaerythrite/time Pentaerythritols branched chain mixed aliphatic ester)

G) the viscosity 9.7mm of 100 ℃ of polyglycols oil ²/ s

(two terminal dimethyl ethers of polyethylene/polypropylene EVA)

On the basis of the reliability of guaranteeing hot-water supply device, the abrasion of control compressor is very important.Therefore, estimating on the hot-water supply device, note the abrasion state of compressor, the state of the rolling of checkout facility front and back, valve.Also to check the residual amount of refrigerator oil of running back compressor.Generally say, with the intermiscibility of cold-producing medium when relatively poor, tail off, cause the insufficient lubrication of sliding part to the recirculating oil quantity of compressor.Adopt the hot-water supply device of embodiment 1～5 again, measure leakage current and COP value.About COP, with the COP of 100% expression comparative example 2.The target of this test be owing to roll/abrasion of valve is no problem, guarantee sufficient resid amount, and leakage current is few, so COP is being will surpass 100% under 100% the situation with comparative example 2.The result of table 1 expression embodiment 1～5 and comparative example 1～2.Put down in writing the independent specific insulation of refrigerator oil, dielectric constant in the table 1 in the lump.

Table 1

		Refrigerator oil	100 ℃ viscosity (mm 2/s)	Roll/valve abrasion situation	Resid amount	Leakage current (℃)	Specific insulation (Ω cm)	Dielectric constant	COP (％)
										Embodiment	1	A	3.59	No problem	No problem	No problem	1×10 16	2.2	103
2	B	4.56	No problem	No problem	No problem	1×10 15	2.3	102
									3		C	4.25	No problem	No problem	No problem	1×10 15	2.2	102
4	D	3.78	No problem	No problem	No problem	1×10 15	2.4	102
									5		E	4.12	No problem	No problem	No problem	1×10 15	2.3	102
Comparative example	1	F	10.2	Abrasion is big	No problem	No problem	1×10 14	3.2											98
									2	E	9.2	Abrasion is arranged slightly	No problem	Leakage current is big	1×10 11	5.5	100

Can find out obviously that from table 1 hot-water supply device of the present invention shown in the embodiment 1～5 is compared with the hot-water supply device of comparative example 1～2,, obtain very high reliability owing to controlled abrasion.About resid amount, also carbon dioxide is shown that the comparative example 1～2 of intermiscibility does not have than big-difference, so, even adopt the refrigerator oil that shows non-intermiscibility, also guarantee sufficient recirculating oil quantity to compressor.

The kind of refrigeration cycle of hot-water supply device does not resemble and becomes low temperature the refrigerator, thus oil be difficult to be detained, thereby this depends on that cold-producing medium can not reduce reasons such as refrigerator oil viscosity to the refrigerator oil dissolving.Also have, almost do not have on the contrary with the leakage problem of embodiment 1～5, its leakage current of the hot-water supply device shown in the comparative example 2 is very big, and the problem of electric shock is arranged.As in the table 1 in the lump shown in the record, the specific insulation of refrigerator oil or dielectric constant be because the refrigerator oil difference of using is different, the polyglycols oil shown in the comparative example 2 especially, and its electrical property is bad.

Hot-water supply device of the present invention shown in the embodiment 1～5 because its cold-producing medium is not dissolved in the refrigerator oil, has sufficient sealing so can guarantee compression unit, compares with comparative example 2 and has improved COP.

Relative therewith, comparative example 1 its cold-producing medium is bigger to the dissolubility of refrigerator oil, and dissolving viscosity descends, and can't guarantee sufficient sealing, and COP descends.In addition, embodiment 5, even adopt the miscella of poly-alpha-olefin and alkanes mineral oil, also obtain and the non-identical effect of a kind of refrigerator oil that mixes of demonstration.Though what adopt among the embodiment is the miscella of poly-alpha-olefin and alkanes mineral oil, as long as will show that other refrigerator oil of non-intermiscibility mixes each other, all can obtain the same result to carbon dioxide.

(embodiment 6～7)

Next, the temperature that is provided with of hot-water supply device is set as the intergrade condition 7 ℃ lower than embodiment 1～5, other conditions and embodiment 1～5 the same test the, measurement project are rolling before and after the investigation test, the state of valve and the residual amount of refrigerator oil of running back compressor.In the present embodiment, will show non-intermiscibility, and viscosity index (VI) surpasses 100 following compound and charges in the compressor to carbon dioxide coolant.

A) the viscosity 3.59mm of 100 ℃ of poly-alpha-olefins ²/ s viscosity index (VI) 122

B) the viscosity 4.56mm of 100 ℃ in alkanes mineral oil ²/ s viscosity index (VI) 101

In the comparative example 3～4, with the viscosity index (VI) of refrigerator oil less than 100 carbon dioxide coolant is shown that the following compound of non-intermiscibility charges in the compressor, carry out the real machine test identical with embodiment 6～7.

C) the viscosity 4.25mm of 100 ℃ in cycloalkane mineral oil ²/ s viscosity index (VI) 15

D) the viscosity 3.78mm of 100 ℃ of alkylbenzenes ²/ s viscosity index (VI)＜0

The result of embodiment 6～7 and comparative example 3～4 is as shown in table 2.

Table 2

		Refrigerator oil	Viscosity index (VI)	Roll/valve abrasion situation	Resid amount
						Embodiment	6	A	122	No problem	No problem
7	B	101	No problem	No problem
					Comparative example		3	C	15	Abrasion is arranged slightly	Reduce
4	D	＜0	Abrasion is big	Reduce

Be clear that from table 2 hot-water supply device of the present invention shown in the embodiment 6～7 has guaranteed the resid amount in the compressor fully, has controlled abrasion, obtains high reliability.About resid amount, surpass at 100 o'clock in the viscosity index (VI) of refrigerator oil, can guarantee fully oil return to compressor.

Relative therewith, at the hot-water supply device shown in the comparative example 3～4, its resid amount reduces, and abrasion also increases.Relevant oil return and since refrigerator oil be detained maximum be the low-temp. portion of kind of refrigeration cycle promptly from pressure reducer 3 to heat exchanger 4, so the viscosity index (VI) of refrigerator oil is big, then the viscosity that causes because of low temperature increases not quite, has guaranteed to be favourable to the compressor oil return.

(embodiment 8)

Next, the temperature that is provided with of hot-water supply device is set as than the low winter conditions-5 of embodiment 6～7 ℃, other conditions and embodiment 1～5 the same test the, measurement project are rolling before and after the investigation test, the state of valve and the residual amount of refrigerator oil of running back compressor.

In the present embodiment, will also obtain the compd A of effect among the embodiment 6) charge in the compressor, adopt the inflow entrance of the refrigerant flow path of heat exchanger 4 top in the unit, the hot-water supply device that flow export is provided with in the bottom.

In comparative example 5, adopt the bottom of the inflow entrance that the refrigerant flow path of heat exchanger 4 and embodiment 8 is opposite in the unit, the hot-water supply device that flow export is provided with in top.

The result of embodiment 8 and comparative example 5 is illustrated in the table 3.

Table 3

		Refrigerator oil	The heat exchanger refrigerant flow path	Roll/valve abrasion situation	Resid amount
						Embodiment	8	A	On → down	No problem	No problem
Comparative example	5	A	Down → on	Abrasion is arranged slightly	Reduce

Be clear that from table 3 the hot-water supply device resid amount of the present invention shown in the embodiment 8 is more, guaranteed to have controlled abrasion to the oil return of the abundance of compressor.

Relative therewith, the hot-water supply device shown in the comparative example 5, its resid amount tails off, and abrasion also increases.About oil return, because it is that the low-temp. portion of kind of refrigeration cycle is promptly from pressure reducer 3 to heat exchanger 4 that refrigerator oil is detained maximum, and in the heat exchanger 4 with the top of its inflow entrance of refrigerant flow path in the unit, flow export is configured in the bottom, so clearly become easy to the oil return of compressor.

(embodiment 9～11)

In embodiment 9～11, the poly-alpha-olefin of obtaining effect in embodiment 6 receives publicity, the effect interdependence implementation evaluation that relative viscosity is changed by the real machine test identical with embodiment 6～7.2.6～13.4mm when the range of viscosities that adopts is 100 ℃ ²/ s.2.0～15.0mm when the viscosity of employing poly-alpha-olefin is 100 ℃ in comparative example 6～7 ²Refrigerator oil outside the scope of/s.Assessment item is identical with embodiment 1～5, measure roll, the abrasion state of valve, the resid amount of refrigerator oil, COP value.About COP, with the COP of comparative example 2 as 100% expression.Desired value as previously mentioned.The result of embodiment 9～11 and comparative example 6～7 is illustrated in the table 4.

Table 4

		Refrigerator oil	100 ℃ viscosity (mm 2/s)	Roll/valve abrasion situation	Resid amount	C0P (％)
							Embodiment	9	A	2.6	No problem	No problem	103
10	A	7.2	No problem	No problem	102
						11		A	13.4	No problem	No problem	101
Comparative example	6	A	1.5	Abrasion is big	No problem								97
						7	A	20.2	Abrasion is big	Reduce	96

Find out obviously that from table 4 at the hot-water supply device of the present invention shown in the embodiment 9～11, it rolls, the abrasion state of valve is all good, also can fully guarantee oil return, especially fully guaranteed the sealing of compression unit, improved COP to compressor.Relative therewith, in comparative example 6, the refrigerator oil viscosity is low excessively, forms inadequate oil film, rolls, the abrasion of valve strengthens, and especially do not guarantee sufficient sealing, COP decline.On the contrary, in the comparative example 7,,, cause resid amount to reduce so the oil that is discharged to kind of refrigeration cycle with refrigerant gas is difficult to turn back to compressor because the refrigerator oil viscosity is too high.Therefore, the fuel delivery to sliding part tails off the abrasion increasing.Particularly, because viscosity is too high,, cause COP to descend so the viscous drag of compressor, mechanical loss increase.

From the result of above embodiment, hot-water supply device of the present invention, the abrasion by the control compressor can fully guarantee the oil return to compressor, and can reduce leakage current, thereby obtains further to improve the hot-water supply device of COP.Though adopt twin-stage compression Rotary Compressor in the present embodiment,, the suspension type compressor of other scroll compressor or roll/being made of one of valve can both be obtained identical effect.

Above-mentioned main feature of the present invention is summarized as follows.

Effect of the present invention is: by the pressure reducer that sucks and the compressor of compression arbon dioxide refrigeration agent, the heat exchanger that will carry out from the refrigeration agent that aforementioned compressor is discharged heat release, the refrigeration agent that will flow out from aforesaid heat exchangers reduce pressure, in the kind of refrigeration cycle that circulates of heat exchanger that the refrigeration agent that is depressurized aforementioned pressure reducer is absorbed heat, freezing machine oil as closed type electromotive compressor, employing shows the poly-alpha-olefin of non-mixing property or any oil in alkanes mineral oil or cycloalkane mineral oil or the alkylbenzene or mixes oil carbon dioxide coolant, thereby obtains controlling the heat-pump water heater that rubs and consume and can reduce electric leakage stream of compressor. And, 2～15mm when being made as 100 ℃ by the kinetic viscosity with freezing machine oil²The scope of/s, the viscosity index (VI) of aforementioned freezing machine oil is surpassed 100, the refrigerant flow path that the refrigeration agent is absorbed on the heat exchanger of heat arranges from top to down, can guarantee the recirculating oil quantity to compressor, the sealing that fully keeps compression section, improve COP, thereby obtain not have the kind of refrigeration cycle of the closely bound up COP of reduction and viscosity resistance or mechanical loss.

Another effect of the present invention is: in possessing the hot-water supply device of aforementioned kind of refrigeration cycle, freezing machine oil as closed type electromotive compressor, employing shows poly-alpha-olefin or the oil of any or these the mixing in alkanes mineral oil or cycloalkane mineral oil or the alkylbenzene of non-mixing property to carbon dioxide coolant, thereby obtains controlling the heat-pump water heater that rubs and consume and can reduce electric leakage stream of compressor. And, 2～15mm when being made as 100 ℃ by the kinetic viscosity with freezing machine oil²The scope of/s, the viscosity index (VI) of aforementioned freezing machine oil is surpassed 100, the refrigerant flow path that the refrigeration agent is absorbed on the heat exchanger of heat arranges from top to down, can guarantee the recirculating oil quantity to compressor, the sealing that fully keeps compression section, improve COP, thereby obtain not have the heat-pump water heater of the closely bound up COP of reduction and viscosity resistance or mechanical loss.

As above narrate, use the present invention, can provide and to guarantee high reliability and can realize saving kind of refrigeration cycle and the heat-pump water heater energy and high efficiency, the love environment.

Claims (4)

1. kind of refrigeration cycle, described kind of refrigeration cycle is provided with: suck and the heat absorption heat exchanger of the described carbon dioxide coolant that the compressor of compression arbon dioxide cold-producing medium, the heat release that flows into the described carbon dioxide coolant of discharging from this compressor are depressurized described pressure reducer with heat exchanger, the pressure reducer that will reduce pressure from the described carbon dioxide coolant that this heat exchanger flows out and inflow;

It is characterized in that:, adopt described carbon dioxide coolant is shown the poly-alpha-olefin of non-intermiscibility or any oil or the miscella in alkanes mineral oil or cycloalkane mineral oil or the alkylbenzene as the refrigerator oil of described compressor;

The described heat absorption refrigerant flow path of heat exchanger, its inflow entrance is positioned at top, flow export is positioned at the bottom.

2. kind of refrigeration cycle, described kind of refrigeration cycle is provided with: suck and the heat absorption heat exchanger of the described carbon dioxide coolant that the compressor of compression arbon dioxide cold-producing medium, the heat release that flows into the described carbon dioxide coolant of discharging from this compressor are depressurized described pressure reducer with heat exchanger, the pressure reducer that will reduce pressure from the described carbon dioxide coolant that this heat exchanger flows out and inflow;

It is characterized in that:, adopt described carbon dioxide coolant is shown that non-intermiscibility, kinetic viscosity are 2～15mm 100 ℃ the time as the refrigerator oil of described compressor ²The scope of/s and the viscosity index (VI) of described refrigerator oil surpass 100 any oil or miscella;

The described heat absorption refrigerant flow path of heat exchanger, its inflow entrance is positioned at top, flow export is positioned at the bottom.

3. heat-pump water heater, described heat-pump water heater possess and are provided with: suck and the compressor of compression arbon dioxide cold-producing medium, the heat release that flows into the described carbon dioxide coolant of discharging from this compressor are used the kind of refrigeration cycle of heat exchanger with heat exchanger, the pressure reducer that will reduce pressure from the described carbon dioxide coolant that this heat exchanger flows out and the heat absorption that flows into the described carbon dioxide coolant that is depressurized described pressure reducer;

It is characterized in that:, adopt described carbon dioxide coolant is shown the poly-alpha-olefin of non-intermiscibility or any oil or the miscella in alkanes mineral oil or cycloalkane mineral oil or the alkylbenzene as the refrigerator oil of described compressor;

The described heat absorption refrigerant flow path of heat exchanger, its inflow entrance is positioned at top, flow export is positioned at the bottom.

4. heat-pump water heater, described heat-pump water heater possess and are provided with: suck and the compressor of compression arbon dioxide cold-producing medium, the heat release that flows into the described carbon dioxide coolant of discharging from this compressor are used the kind of refrigeration cycle of heat exchanger with heat exchanger, the pressure reducer that will reduce pressure from the described carbon dioxide coolant that this heat exchanger flows out and the heat absorption that flows into the described carbon dioxide coolant that is depressurized described pressure reducer;

It is characterized in that:, adopt described carbon dioxide coolant is shown that non-intermiscibility, kinetic viscosity are 2～15mm 100 ℃ the time as the refrigerator oil of described compressor ²The scope of/s and the viscosity index (VI) of described refrigerator oil surpass 100 any oil or miscella;

The described heat absorption refrigerant flow path of heat exchanger, its inflow entrance is positioned at top, flow export is positioned at the bottom.

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