U.S. patent application number 12/067429 was filed with the patent office on 2009-02-19 for refrigerant composition.
This patent application is currently assigned to Japan Petroleum Exploration Co., Ltd.. Invention is credited to Toshifumi Hatanaka, Yasuhisa Kotani, Seijyuro Maiya, Osamu Nakagome, Hideyuki Suzuki, Toshihiro Wada.
Application Number | 20090045375 12/067429 |
Document ID | / |
Family ID | 37899507 |
Filed Date | 2009-02-19 |
United States Patent
Application |
20090045375 |
Kind Code |
A1 |
Maiya; Seijyuro ; et
al. |
February 19, 2009 |
Refrigerant Composition
Abstract
[Problems] To provide a safe, nontoxic, and high-performance
mixed refrigerant for hot water supply/heating system which is
prepared by mixing dimethyl ether with carbon dioxide and which
does not deplete the ozone layer, has a low global warming
potential, and permits low-pressure operation. [Means for Solving
Problems] A refrigerant composition for hot water supply/heating
comprising 1 to 10% by mole of dimethyl ether and 99 to 90% by mole
of carbon dioxide on the basis of the total number of moles of
dimethyl ether and carbon dioxide.
Inventors: |
Maiya; Seijyuro; (Tokyo,
JP) ; Nakagome; Osamu; (Tokyo, JP) ; Suzuki;
Hideyuki; (Kanagawa, JP) ; Kotani; Yasuhisa;
(Tokyo, JP) ; Hatanaka; Toshifumi; (Nara, JP)
; Wada; Toshihiro; (Chiba, JP) |
Correspondence
Address: |
THOMPSON COBURN, LLP
ONE US BANK PLAZA, SUITE 3500
ST LOUIS
MO
63101
US
|
Assignee: |
Japan Petroleum Exploration Co.,
Ltd.
Tokyo
JP
|
Family ID: |
37899507 |
Appl. No.: |
12/067429 |
Filed: |
August 16, 2006 |
PCT Filed: |
August 16, 2006 |
PCT NO: |
PCT/JP2006/316088 |
371 Date: |
May 29, 2008 |
Current U.S.
Class: |
252/67 |
Current CPC
Class: |
F25B 9/006 20130101;
C09K 5/041 20130101 |
Class at
Publication: |
252/67 |
International
Class: |
C09K 5/00 20060101
C09K005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 27, 2005 |
JP |
2005-279209 |
Claims
1. A refrigerant composition for hot water supply/heating
comprising 1 to 10% by mole of dimethyl ether and 99 to 90% by mole
of carbon dioxide on the basis of the total number of moles of
dimethyl ether and carbon dioxide.
2. The refrigerant composition according to claim 1 comprising 3 to
8% by mole of dimethyl ether and 97 to 92% by mole of carbon
dioxide.
3. A method of using a refrigerant composition comprising 1 to 10%
by mole of dimethyl ether and 99 to 90% by mole of carbon dioxide
on the basis of the total number of moles of dimethyl ether and
carbon dioxide in a hot water supply apparatus/heater.
Description
TECHNICAL FIELD
[0001] The present invention relates to a refrigerant composition
containing dimethyl ether and carbon dioxide used for a heat pump
hot water supply.
BACKGROUND ART
[0002] Carbon dioxide has zero ozone-depleting potential, global
warming potential of exactly 1 and extremely small environmental
load as well as absence of toxicity, and flammability, safety, low
price, and a low critical temperature of 31.1.degree. C. Since in
an air conditioning system and a hot-water system, heating can be
performed even in a small temperature difference between the
refrigerant and the refrigerated fluid due to readily attaining the
supercritical point in a high pressure side of the cycling. As a
result, in the heating process with large warm-up range as like
hot-water supply, carbon dioxide is currently widely used as the
refrigerant for a heat pump hot water supply under the naming of
"ecocute", since high coefficient of performance can be obtained;
high heating ability in input volume per unit of compressor can be
expected; and high thermal conductivity can be obtained.
[0003] However, since a working pressure of a carbon dioxide
refrigerant is rather high as about 10 MPa compared with other
refrigerants and as a result, each and every part of the system
device should be assembled by super high pressure specifications,
development of an elemental technology of the cycle system with
appropriate prices remains a big issue.
DISCLOSURE OF THE INVENTION
[0004] An object of the present invention is to provide a safe,
non-toxic refrigerant composition for hot water supply/heating as
an alternative to carbon dioxide supercritical refrigerant. Such
refrigerant composition has a small risk for depleting the ozone
layer, has small damaging effect on the global warming, exhibits
incombustibility or fire retardancy, and operates at lower
pressures while exhibiting excellent performance.
[0005] Carbon dioxide has a critical temperature of 31.1.degree. C.
and a boiling point of -56.6.degree. C., whereas dimethyl ether has
a critical temperature of 126.85.degree. C. and a boiling point of
-25.degree. C., indicating a great difference between the two in
their physical property. For that reason, carbon dioxide is
utilized as a refrigerant in a very high pressure region such as
low pressure at about 3 MPa to high pressure at about 10 MPa,
whereas dimethyl ether is utilized as a refrigerant in a
comparatively low pressure region such as low pressure at about 0.7
MPa to high pressure at about 2 MPa, and is known to exert best
performance as the refrigerant under such pressure condition.
Consequently, although carbon dioxide and dimethyl ether have been
used alone as the refrigerant, an idea of trying to utilize as the
refrigerant by mixing carbon dioxide and dimethyl ether having
completely different properties has not been made or examined.
[0006] Contrary to that, the present inventors have tried to
perform an assessment test and a macroscopic test on solubility of
carbon dioxide in dimethyl ether and have confirmed that although
the amount of mass transfer (dissolved amount) to gas-liquid
equilibrium is changed depending on the conditions of temperature
and pressure, carbon dioxide was dissolved and diffused well in
dimethyl ether. The present inventors have considered the
possibilities of obtaining physical properties showing extremely
high thermal efficiency by mixing carbon dioxide which has
physically high efficiency of heat transfer (0.02 W/mK) and
dimethyl ether which has higher specific heat (138 J/molK),
continued the development and simulation, and found that the
mixture of dimethyl ether and carbon dioxide was a refrigerant for
heating/hot water supply which could operate at low pressure while
exhibiting excellent coefficient of performance, and completed the
present invention.
TABLE-US-00001 Carbon dioxide Dimethyl ether Specific heat (J/molK)
30-40 138 Thermal conductivity (W/mK) 0.02 0.013
[0007] The present invention relates to a refrigerant composition
for hot water supply/heating comprising 1 to 10% by mole of
dimethyl ether and 99 to 90% by mole of carbon dioxide on the basis
of the total number of moles of dimethyl ether and carbon
dioxide.
[0008] As explained hereinabove, a mixture of dimethyl ether and
carbon dioxide of the present invention is a refrigerant which has
superior heating and hot water supplying ability, does not deplete
the ozone layer, has almost zero global warming potential (GWP), is
safe and non-toxic, and operates at low pressure while exhibiting
excellent performance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a Pattern diagram of hot water supply system;
and
[0010] FIG. 2 is a DME CO.sub.2B programming flow-chart.
BEST MODE FOR CARRYING OUT THE INVENTION
[0011] Preferable embodiments of the present invention will be
explained in detail hereinbelow.
[0012] Dimethyl ether used in the refrigerant composition of the
present invention can be obtained by synthesizing dimethyl ether
directly from hydrogen and carbon monoxide or indirectly from
hydrogen and carbon monoxide through methanol synthesis by
utilizing raw materials of a coal gasification gas, a BOG (boil of
gas) of LNG tank, natural gases, by-product gases from a steel
plant, oil residues, waste products and biogas.
[0013] Carbon dioxide used in the refrigerant composition of the
present invention can be obtained by compression, liquefaction and
purification of ammonium synthesis gas and by-product gas as the
raw material generated from a hydrogen manufacturing plant for
desulfurization of fuel oil.
[0014] A mixing ratio of dimethyl ether and carbon dioxide in the
refrigerant composition of the present invention is appropriately
determined depending on types of a hot water supply/heater in which
the refrigerant is used. The refrigerant composition of the present
invention contains, on the basis of the total number of moles of
dimethyl ether and carbon dioxide, preferably dimethyl ether at 1
to 10% by moles and carbon dioxide at 99 to 90% by moles, more
preferably dimethyl ether at 3 to 8% by moles and carbon dioxide at
97 to 92% by moles. If a ratio of dimethyl ether is less than 1% by
mole, a coefficient of the performance hereinafter described
decreases, and it is not preferred as an effect of adding dimethyl
ether is not exhibited. On the other hand, if the ratio of dimethyl
ether is more than 10% by moles, since the refrigerant composition
is out of an inflammable range, it is unfavorable on safety reason
when particularly high safety standard is required (for example, a
direct leakage system in which a refrigerant filling unit exists in
a room or use in a place such as in a room where the space is
sealed).
[0015] The mixing ratio of the refrigerant composition of the
present invention can be obtained, for example, by filling a
predetermined amount of liquid dimethyl ether in a vessel from a
tank filled with liquid dimethyl ether, subsequently filling a
predetermined amount of liquid carbon dioxide thereto from a tank
filled with liquid carbon dioxide. Further, after filling the
predetermined amount of liquid dimethyl ether in the vessel, the
refrigerant composition of the present invention can be prepared by
such that carbon dioxide gas is filled into the gas phase part of
the vessel and is dissolved and mixed under pressure into dimethyl
ether.
[0016] In the refrigerant composition of the present invention, for
example, water as another additive can be added. Since water can be
dissolved about a little over 7% by mole in dimethyl ether under
the conditions of 1 atmospheric pressure at 18.degree. C., and has
the characteristics of higher vaporization (condensation) latent
heat as well as having a small rate of temperature change to the
vaporization latent heat due to a high critical point, as a result
large latent heat can be obtained even in a high-temperature
region. Consequently, it is estimated to obtain further high
thermal efficiency by admixing three types of substance, i.e.
carbon dioxide having high sensible heat effect, and dimethyl ether
and water both having high latent heat effect. A ratio of mixing
water in this case is determined not to exceed 7% by mole in
consideration of solubility to dimethyl ether.
Method for Evaluation of Refrigerant Characteristics
Hot Water Supply System
[0017] A hot water supply system is generally composed of a
compressor, a condenser, an extender and a vaporizer as shown in
FIG. 1, and hot water for hot water supply is generated by
performing heat exchange between a high temperature refrigerant
from the compressor and cold water at condenser. A working pressure
in the condenser side becomes supercritical (CO.sub.2 critical
pressure: 7.4 MPa) at a high pressure of 9 MPa or more in the
CO.sub.2 refrigerant hot water supply cycle, the working pressure
of the vaporizer in the low pressure side constitutes transition
critical cycle of 3 MPa or more.
[0018] Simulation for hot water supply performance of CO.sub.2/DME
refrigerant In order to evaluate hot water supply performance of
a_CO.sub.2/DME refrigerant, a numerical model of a standard cycle
for hot water supply in FIG. 1 is prepared, and using a
general-purpose simulation system for a numerical chemical process,
the hot water supply performance of the CO.sub.2/DME refrigerant
can be analyzed and evaluated by the known method (e.g. see Miyara
et al., "Effect of heat transfer characteristics of heat exchanger
on non-azeotropic mixture refrigerant heat pump cycle,"
Transactions of the Japanese Association of Refrigeration, 7(1):
65-73, 1990). The general-purpose simulation system for the
numerical chemical process stores database of thermodynamic
properties of various components, and equilibrium thermodynamic
calculation on interaction of chemical components corresponding to
a mechanical engineering function of various systems can be
performed.
[0019] In the numerical simulation, a system circulating the
refrigerant composed of a compressor, a circulator, an expander and
a vaporizer is expressed numerically, and the hot water supply
performance is evaluated as coefficient of performance (COP) by
using parameters of output pressure of compressor (P1), discharge
temperature of condenser (T2), temperature of a vaporizer (T3) and
molar concentration of dimethyl ether/CO.sub.2.
Hot water supply COP=total amount of exhaust heat of refrigerant in
condenser/amount of power of compressor
[0020] The present invention can be highly precisely evaluated by
applying, preferably as an estimate equation for thermodynamic
physical value of refrigerant, regular solution model with respect
to dissolution and SRK (Soave-Redlich-Kwong) equation of state with
respect to the equation of state, respectively.
[0021] The refrigerant composition of the present invention can be
fundamentally used directly in conventional carbon dioxide heat
pump water supply known as naming of ecocute. However, considering
the physical properties of the refrigerant of the present
invention, a mechanical aspect of a condenser, a piston, etc. can
be appropriately improved and designed in conformity with the
refrigerant composition of the present invention.
EXAMPLES
[0022] The present invention will be described with reference to
examples hereinbelow in detail, however the present invention is
not limited within these examples.
[0023] Solubility Test of Dimethyl Ether/Carbon Dioxide
[0024] In order to know solubility of a mixture system of dimethyl
ether (DME) and carbon dioxide (CO.sub.2), and in order to obtain
coefficient of performance of the mixed refrigerant in the hot
water supply system described hereinbelow, a solubility test of
DME/CO.sub.2 was performed. The test method is as follows.
(1) 300 g of dimethyl ether was encapsulated and sealed in a 500-mL
pressure vessel, and weight of the sealed vessel was measured by
using an electric weighing machine. (2) The pressure vessel was set
in the constant-temperature bath and kept at a constant
temperature. (3) Carbon dioxide was injected by using a booster
pump until obtaining a constant pressure. (4) Weight of the filled
carbon dioxide was calculated by weighing before and after filling
(d=0.1 g).
[0025] In the filling, the pressure vessel was shaken up and down
for completely mixing DME/CO.sub.2, and the test was performed
after allowing to stand vertically.
[0026] Results obtained are shown in Table 1. As shown in Table 1,
values of K-volume of CO.sub.2 and DME are within the range of
0.66<KDME<0.80 and 2.59<KCO.sub.2<3.42, under the
measuring conditions respectively, and it shows that carbon dioxide
dissolves well in DME.
TABLE-US-00002 TABLE 1 Solubility test results of DME/CO.sub.2 Case
A B C D Pressure of system 10.0 10.0 10.0 1.0 Temperature of system
(.degree. C.) 10 20 30 40 ZCO.sub.2 (g-mol) 1.682 1.500 0.977 1.045
ZDME (g-mol) 6.522 6.522 6.522 6.522 V (g-mol) 1.177 1.378 2.090
0.661 L (g-mol) 7.027 6.634 5.409 6.906 YCO.sub.2 (mol %) 43.2 42.9
26.3 39.0 XCO.sub.2 (mol %) 16.7 13.7 7.9 11.4 KCO.sub.2 (--) 2.59
3.13 3.33 3.42 YDME (mol %) 56.8 57.1 73.7 61.0 XDME (mol %) 83.7
86.3 92.1 88.6 KDME 0.68 0.66 0.80 0.69 ZCO.sub.2 = V .times.
YCO.sub.2 + L .times. CO.sub.2 ZCO.sub.2 + ZDME = V + L KCO.sub.2 =
YCO.sub.2/XCO.sub.2 KDME = YDME/XDME
[0027] Coefficient of performance (COP) of the mixed refrigerant of
dimethyl ether and carbon dioxide in the hot water supply system
shown in FIG. 1 is obtained. Simulation using the simulation
chemical system for the numerical process was performed by
following operation procedure.
Simulation Procedure
[0028] A quantity of state of stream (1) to (4) (volume, enthalpy,
entropy, etc.) in the hot water supply system in FIG. 1 was
determined by simulation to obtain coefficient of performance (COP)
of the following equation.
COP=H1/H2
[0029] H1: total amount of exhaust heat of refrigerant in condenser
(total amount of heat absorption of refrigerant in vaporizer+amount
of power of compressor)
[0030] H2: amount of power of compressor from (4) to (1)
[0031] Condition setting was as follows.
(1) DME/CO.sub.2 Mixed Refrigerant
[0032] In order to evaluate hot water supply ability of a
DME/CO.sub.2 mixed refrigerant, the output pressure of the
compressor (discharge pressure), P1, the output temperature of the
condenser (discharge temperature), P2, the pressure of the
vaporizer, P3 and the mixing ratio of DME/CO.sub.2 were used as
fluctuating parameter for calculation. Herein, an outlet
temperature of the condenser of the refrigerant was set at
15.degree. C.
[0033] P1=9.16 MPa to 6.31 MPa
[0034] P3=2.90 MPa to 2.55 MPa
[0035] Discharge temperature=130.degree. C., 120.degree. C.,
100.degree. C.
[0036] Mixing ratio of DME/CO.sub.2=3/97, 4/96, 5/95, 6/94 (molar
ratio)
(2) CO.sub.2 Refrigerant Alone
[0037] For a carbon dioxide refrigerant alone, the simulation was
performed by using the discharge pressure of the compressor (P1),
the discharge temperature and the pressure of the vaporizer (P3) as
fluctuating parameter. Herein, an outlet temperature of the
condenser of the refrigerant was set at 15.degree. C.
[0038] P1=10 MPa to 8 MPa
[0039] P3=3.18 MPa to 2.97 MPa
Estimation of Gas-Liquid Equilibrium Physical Properties of
DME/CO.sub.2 Mixed System
[0040] In the simulation study, the accuracy of the employed
estimation model for physical properties is an important factor and
a trial examination was performed as follows.
[0041] In general, a gas-liquid equilibrium relation is expressed
in the following equation.
.phi. i Py i = f i ( 0 ) .gamma. i ( 0 ) x i .times. exp .intg. 0 P
V _ i L / RT dp ##EQU00001##
.phi.i Gas phase Fugacity Coeff.
P: System Pressure
[0042] yi: Gas phase mol fraction f.sub.i.sup.(0): Liquid phase
standard Fugacity .gamma..sub.i.sup.(0): Activity coefficient of
liquid phase x.sub.i: Liquid phase mol fraction
exp .intg. 0 P V _ i L / RT dp : ##EQU00002##
[0043] Poynting Factor
[0044] Points to be considered are following three points.
(1) .gamma..sub.i.sup.(0) model for DME (2) Degree of relative
volatility of DME and CO.sub.2 (3) Enthalpy and entropy model
[0045] Although DME is an oxygen containing low molecular weight
compound, since the boiling point of the representative substance,
ethanol, is 78.degree. C., whereas that of DME is -25.degree. C.,
it can be understood that it has no strong polarity as compared
with alcohol, aldehyde and ketone groups. Consequently, a regular
dissolution model can be applied for .gamma..sub.i.sup.(0) of
DME.
[0046] As obtained from DME/CO.sub.2 solubility test data (Table
1), values of K-volume of DME and CO.sub.2 are within the range of
0.66<KDME<0.80 and 2.59<KCO.sub.2<3.42, respectively,
indicating that there is no large difference in volatility between
DME and CO.sub.2. Consequently, a vapor pressure model can be
applied for f.sub.i.sup.(0).
[0047] Since the estimated maximum pressure for use in DME+CO.sub.2
system with regard to enthalpy and entropy is approximately 10 MPa,
SRK (Soave-Redlich-Kwong) equation of state can suitably be
employed.
P = RT v - b - a [ 1 + ( 0.48 + 1.574 w - 0.176 w 2 ) ( 1 - Tr ) 1
/ 2 ] 2 v 2 + bv ##EQU00003##
[0048] .gamma..sub.i.sup.(0): Regular Solution Model
f.sub.i.sup.(0): Vaper Pressure Model .phi.i, H, S: SRK equation of
State
Poynting Factor: Considered
[0049] When pressure of the system become high in some degree
(several MPa), Poynting factor cannot be negligible, consequently
this point was also taken into consideration.
Program
[0050] The following two programs, A and B were used.
(1) DME CO.sub.2 A
[0051] Flash calculation under given composition, T (temperature)
and P (pressure).
[0052] A bubble point was calculated under the given composition
and P1 (the output pressure of the compressor).
[0053] According to this condition, confirmation for an accuracy of
gas-liquid equilibrium physical property estimation model and
whether total condensation in the condenser can be in sight.
(2) DME CO.sub.2 B
[0054] Using the above explained simulator, COP of carbon dioxide
alone and the refrigerant containing dimethyl ether and carbon
dioxide were obtained as follows.
[0055] Simulation of hot water supply ability of a dimethyl
ether/carbon dioxide mixed refrigerant
[0056] In order to evaluate hot water supply ability of a dimethyl
ether/carbon dioxide mixed refrigerant, simulation was performed by
using the discharge pressure of the compressor, the discharge
temperature, the pressure of the vaporizer and the mixing ratio of
DME/CO.sub.2 as fluctuating parameter for calculation under the
above described conditions. Hereinbelow, simulation results of a
refrigerant properly in each DME/CO.sub.2 mixing ratio (mot %) are
shown. In the following table, "inlet/outlet" of the evaporation
temperatures of a refrigerant indicate temperatures of the
refrigerant in the inlet and the outlet of the vaporizer.
[0057] Herein, Tables 2-1 to 2-5 show simulation results at a
discharge temperature of 130.degree. C., tables 3-1 to 3-5 show
simulation results at a discharge temperature of 120.degree. C.,
and Tables 4-1 to 4-5 show simulation results at a discharge
temperature of 100.degree. C.
TABLE-US-00003 TABLE 2-1 CO.sub.2 refrigerant alone (discharge
temperature: 130.degree. C.) Total heat Amount of Discharge
Discharge absorption amount power of Vaporization Vaporization
pressure temperature in vaporizer compressor pressure temperature
(.degree. C.) (MPa) (.degree. C.) (KCAL/H) (KCAL/H) (MPa)
inlet/outlet COP 10 130.2 224290 104310 3.08 -0.1/-0.1 3.15 10
129.8 224240 103910 3.09 0.0/0.0 3.16
TABLE-US-00004 TABLE 2-2 DME/CO.sub.2 = 3/97 (mol %) (discharge
temperature: 130.degree. C.) Total heat Amount of Discharge
Discharge absorption amount power of Vaporization Vaporization
pressure temperature in vaporizer compressor pressure temperature
(.degree. C.) (MPa) (.degree. C.) (KCAL/H) (KCAL/H) (MPa)
inlet/outlet COP 9.10 129.3 223580 105470 2.8 -6.5/0.2 3.21 9.13
129.7 233650 105840 2.8 -6.5/0.2 3.21 9.16 130.0 233710 106190 2.8
-6.5/0.2 3.20
TABLE-US-00005 TABLE 2-3 DME/CO.sub.2 = 4/96 (mol %) (discharge
temperature: 130.degree. C.) Total heat Amount of Discharge
Discharge absorption amount power of Vaporization Vaporization
pressure temperature in vaporizer compressor pressure temperature
(.degree. C.) (MPa) (.degree. C.) (KCAL/H) (KCAL/H) (MPa)
inlet/outlet COP 9.00 132.0 238520 107490 2.75 -6.6/2.1 3.22 9.00
130.3 238330 105320 2.80 -6.0/2.6 3.26 9.00 128.7 238130 103200
2.85 -5.3/3.2 3.31 9.00 127.2 237920 101280 2.90 -4.7/3.8 3.35
TABLE-US-00006 TABLE 2-4 DME/CO.sub.2 = 5/95 (mol %) (discharge
temperature: 130.degree. C.) Total heat Amount of Discharge
Discharge absorption amount power of Vaporization Vaporization
pressure temperature in vaporizer compressor pressure temperature
(.degree. C.) (MPa) (.degree. C.) (KCAL/H) (KCAL/H) (MPa)
inlet/outlet COP 8.48 130.3 242550 106150 2.65 -7.4/3.1 3.28 8.46
130.0 242500 105880 2.65 -7.4/3.1 3.29 8.44 129.7 242460 105610
2.65 -7.4/3.1 3.30
TABLE-US-00007 TABLE 2-5 DME/CO.sub.2 = 6/94 (mol %) (discharge
temperature: 130.degree. C.) Total heat Amount of Discharge
Discharge absorption amount power of Vaporization Vaporization
pressure temperature in vaporizer compressor pressure temperature
(.degree. C.) (MPa) (.degree. C.) (KCAL/H) (KCAL/H) (MPa)
inlet/outlet COP 8.05 129.4 246560 105690 2.55 -8.2/4.1 3.33 8.07
129.7 246600 105970 2.55 -8.2/4.1 3.33 8.10 130.2 246660 106400
2.55 -8.2/4.1 3.32 8.06 129.6 246580 105830 2.55 -8.2/4.1 3.33
TABLE-US-00008 TABLE 3-1 CO.sub.2 refrigerant alone (discharge
temperature: 120.degree. C.) Total heat Amount of Discharge
Discharge absorption amount power of Vaporization Vaporization
pressure temperature in vaporizer compressor pressure temperature
(.degree. C.) (MPa) (.degree. C.) (KCAL/H) (KCAL/H) (MPa)
inlet/outlet COP 9.00 119.9 222310 96214 2.99 -1.0/-1.0 3.31 9.00
120.2 222360 96609 2.98 -1.2/-1.2 3.30 9.00 120.5 222410 97006 2.97
-1.3/-1.3 3.29
TABLE-US-00009 TABLE 3-2 DME/CO.sub.2 = 3/97 (mol %) (discharge
temperature: 120.degree. C.) Total heat Amount of Discharge
Discharge absorption amount power of Vaporization Vaporization
pressure temperature in vaporizer compressor pressure temperature
(.degree. C.) (MPa) (.degree. C.) (KCAL/H) (KCAL/H) (MPa)
inlet/outlet COP 8.45 120.2 232090 97315 2.80 -6.5/0.2 3.38 8.43
119.9 232040 97053 2.80 -6.5/0.2 3.39 8.40 119.5 231960 96660 2.80
-6.5/0.2 3.40
TABLE-US-00010 TABLE 3-3 DME/CO.sub.2 = 4/96 (mol %) (discharge
temperature: 120.degree. C.) Total heat Amount of Discharge
Discharge absorption amount power of Vaporization Vaporization
pressure temperature in vaporizer compressor pressure temperature
(.degree. C.) (MPa) (.degree. C.) (KCAL/H) (KCAL/H) (MPa)
inlet/outlet COP 8.00 120.0 236490 97437 2.68 -7.5/1.2 3.43 8.00
120.3 236530 97872 2.67 -7.6/1.1 3.42 8.00 119.7 236460 97003 2.69
-7.4/1.3 3.44 8.00 120.7 236560 98311 2.66 -7.8/1.0 3.41
TABLE-US-00011 TABLE 3-4 DME/CO.sub.2 = 5/95 (mol %) (discharge
temperature: 120.degree. C.) Total heat Amount of Discharge
Discharge absorption amount power of Vaporization Vaporization
pressure temperature in vaporizer compressor pressure temperature
(.degree. C.) (MPa) (.degree. C.) (KCAL/H) (KCAL/H) (MPa)
inlet/outlet COP 7.75 119.4 240870 96156 2.65 -7.4/3.1 3.51 7.80
120.2 241000 96869 2.65 -7.4/3.1 3.49 7.85 121.0 241120 97579 2.65
-7.4/3.1 3.47
TABLE-US-00012 TABLE 3-5 DME/CO.sub.2 = 6/94 (mol %) (discharge
temperature: 120.degree. C.) Total heat Amount of Discharge
Discharge absorption amount power of Vaporization Vaporization
pressure temperature in vaporizer compressor pressure temperature
(.degree. C.) (MPa) (.degree. C.) (KCAL/H) (KCAL/H) (MPa)
inlet/outlet COP 7.47 120.4 245220 97361 2.55 -8.2/4.1 3.52 7.47
120.4 245210 97287 2.55 -8.2/4.1 3.52 7.46 120.3 245200 97212 2.55
-8.2/4.1 3.52
TABLE-US-00013 TABLE 4-1 CO.sub.2 refrigerant alone (discharge
temperature: 100.degree. C.) Total heat Amount of Discharge
Discharge absorption amount power of Vaporization Vaporization
pressure temperature in vaporizer compressor pressure temperature
(.degree. C.) (MPa) (.degree. C.) (KCAL/H) (KCAL/H) (MPa)
inlet/outlet COP 8.00 99.8 218430 76756 3.18 1.0/1.0 3.85 8.00
100.3 218530 77446 3.16 0.8/0.8 3.82 8.00 100.9 218640 78143 3.14
0.6/0.6 3.80
TABLE-US-00014 TABLE 4-2 DME/CO.sub.2 = 3/97 (mol %) (discharge
temperature: 100.degree. C.) Total heat Amount of Discharge
Discharge absorption amount power of Vaporization Vaporization
pressure temperature in vaporizer compressor pressure temperature
(.degree. C.) (MPa) (.degree. C.) (KCAL/H) (KCAL/H) (MPa)
inlet/outlet COP 7.13 99.7 228450 79250 2.80 -6.5/0.2 3.88 7.15
100.1 228510 79537 2.80 -6.5/0.2 3.87
TABLE-US-00015 TABLE 4-3 DME/CO.sub.2 = 4/96 (mol %) (discharge
temperature: 100.degree. C.) Total heat Amount of Discharge
Discharge absorption amount power of Vaporization Vaporization
pressure temperature in vaporizer compressor pressure temperature
(.degree. C.) (MPa) (.degree. C.) (KCAL/H) (KCAL/H) (MPa)
inlet/outlet COP 7.00 100.0 233330 78249 2.80 -5.9/2.6 3.98 7.00
98.5 233130 76333 2.85 -5.3/3.2 4.05 7.00 97.6 233010 75205 2.88
-4.9/3.6 4.10 7.00 97.0 232920 74462 2.90 -4.7/3.8 4.13
TABLE-US-00016 TABLE 4-4 DME/CO.sub.2 = 5/95 (mol %) (discharge
temperature: 100.degree. C.) Total heat Amount of Discharge
Discharge absorption amount power of Vaporization Vaporization
pressure temperature in vaporizer compressor pressure temperature
(.degree. C.) (MPa) (.degree. C.) (KCAL/H) (KCAL/H) (MPa)
inlet/outlet COP 6.60 100.1 237740 78958 2.65 -7.3/3.1 4.01 6.55
99.2 237590 78173 2.65 -7.3/3.1 4.04 6.57 99.6 237650 78487 2.65
-7.3/3.1 4.03 6.54 99.1 237560 78015 2.65 -7.3/3.1 4.05
TABLE-US-00017 TABLE 4-5 DME/CO.sub.2 = 6/94 (mol %) (discharge
temperature: 100.degree. C.) Total heat Amount of Discharge
Discharge absorption amount power of Vaporization Vaporization
pressure temperature in vaporizer compressor pressure temperature
(.degree. C.) (MPa) (.degree. C.) (KCAL/H) (KCAL/H) (MPa)
inlet/outlet COP 6.34 100.8 242180 79676 2.55 -8.1/4.1 4.04 6.33
100.6 242150 79512 2.55 -8.1/4.1 4.05 6.31 100.2 242090 79183 2.55
-8.1/4.1 4.06
[0058] As obvious from Tables 2-1 to 4-5, when the same discharge
temperature is intended to be obtained, as a mixing amount of DME
is larger, a discharge pressure decreases, and a distance between a
condensation point and a boiling point in a two-layered region
which corresponds to a vaporization process in the Mollier diagram
becomes wider, and COP becomes high. That is, as compared with a
carbon dioxide refrigerant alone, a higher discharge temperature is
obtained at a lower discharge pressure, which results in a higher
total amount of exhaust heat can be obtained in a condenser.
[0059] From the above result, in the system operating at the
condenser discharge temperature at 15.degree. C. or less, the
refrigerant composition of the present invention can be expected
for utilization in the refrigerant for domestic hot water
supply/heating system, the refrigerant for industrial air
conditioning (heat pump) and refrigerating machine, and the
refrigerant for heat pump utilizing geothermal heat to an alleviate
heat-island phenomenon.
* * * * *