Energy-saving CNG (compressed natural gas) recovery integrated pry

Abstract

The utility model discloses an energy-saving CNG (compressed natural gas) recovery integrated pry, and belongs to the technical field of natural gas purification. The utility model discloses an energy-saving CNG recovery integrated pry. Comprising a feed gas separator, a CNG compressor, a first molecular sieve dehydration tower, a second molecular sieve dehydration tower, a third molecular sieve dehydration tower, a regeneration gas unit, a first valve, a second valve, a third valve, a fourth valve, a fifth valve, a sixth valve, a seventh valve, an eighth valve, a ninth valve, a tenth valve, an eleventh valve, a twelfth valve and a thirteenth valve, a fourteenth valve, a fifteenth valve and a sixteenth valve. According to the utility model, the energy consumption of the regeneration gas air cooler and the regeneration gas heater is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of natural gas purification, and particularly relates to an energy-saving CNG recovery integrated skid. Background Art

[0002] At present, the natural gas from marginal wells and production test wells is often recovered by CNG truck transportation. CNG needs dehydration treatment to meet the requirements of "Vehicle Compressed Natural Gas". Currently, the commonly used CNG dehydration method is molecular sieve dehydration, which is divided into pre-dehydration and post-dehydration according to whether it is placed before or after the compressor. Since the water content of natural gas has a great relationship with pressure and temperature, the pre-dehydration operation pressure is low, so the pre-dehydration equipment has a large volume and a large dehydration load; the post-dehydration is relatively small in volume, but during the CNG filling process, the pressure of the post-dehydration system of CNG increases as the CNG tanker is continuously filled. If the fixed post-dehydration pressure does not change with the tanker pressure, the compressor energy consumption will increase.

[0003] During the process of molecular sieve dehydration of CNG, the heated regeneration gas is used during the hot blow of the molecular sieve dehydration tower, and the cooled regeneration gas is used during the cold blow of the molecular sieve dehydration tower. Therefore, cooling and heating the regeneration gas will increase a large amount of energy consumption. Summary of the Utility Model

[0004] The purpose of the utility model is to overcome the deficiencies of the prior art and provide an energy-saving CNG recovery integrated skid.

[0005] The purpose of the utility model is realized by the following technical solutions: An energy-saving CNG recovery integrated skid includes a raw gas separator, a CNG compressor, a first molecular sieve dehydration tower, a second molecular sieve dehydration tower, a third molecular sieve dehydration tower, and a regeneration gas unit;

[0006] The air inlet of the CNG compressor is connected to the air outlet of the raw gas separator;

[0007] The top opening of the first molecular sieve dehydration tower is connected to the air outlet of the CNG compressor through a first valve, the top opening of the first molecular sieve dehydration tower is connected to the air inlet of the regeneration gas unit through a second valve, the bottom opening of the first molecular sieve dehydration tower is connected to the top opening of the second molecular sieve dehydration tower through a third valve, the bottom opening of the first molecular sieve dehydration tower is connected to the air outlet of the regeneration gas unit through a fourth valve, and the bottom opening of the first molecular sieve dehydration tower is sequentially connected to a gas dispenser through a fifth valve and a sixteenth valve;

[0008] The top opening of the second molecular sieve dehydration tower is connected to the outlet of the CNG compressor through a sixth valve. The top opening of the second molecular sieve dehydration tower is connected to the inlet of the regeneration gas unit through a seventh valve. The bottom opening of the second molecular sieve dehydration tower is connected to the top opening of the third molecular sieve dehydration tower through an eighth valve. The bottom opening of the second molecular sieve dehydration tower is connected to the outlet of the regeneration gas unit through a ninth valve. The bottom opening of the second molecular sieve dehydration tower is sequentially connected to the gas dispenser through a tenth valve and a sixteenth valve;

[0009] The top opening of the third molecular sieve dehydration tower is connected to the outlet of the CNG compressor through an eleventh valve. The top opening of the third molecular sieve dehydration tower is connected to the inlet of the regeneration gas unit through a twelfth valve. The bottom opening of the third molecular sieve dehydration tower is connected to the top opening of the first molecular sieve dehydration tower through a thirteenth valve. The bottom opening of the third molecular sieve dehydration tower is connected to the outlet of the regeneration gas unit through a fourteenth valve. The bottom opening of the third molecular sieve dehydration tower is sequentially connected to the gas dispenser through a fifteenth valve and a sixteenth valve.

[0010] Further, the first valve, the second valve, the third valve, the fourth valve, the fifth valve, the sixth valve, the seventh valve, the eighth valve, the ninth valve, the tenth valve, the eleventh valve, the twelfth valve, the thirteenth valve, the fourteenth valve, the fifteenth valve, and the sixteenth valve are all programmable control valves.

[0011] Further, the regeneration gas unit includes a regeneration gas air cooler, a regeneration gas separator, a regeneration gas circulation fan, and a regeneration gas heater connected in series in sequence. The inlet of the regeneration gas air cooler is configured as the inlet of the regeneration gas unit. The outlet of the regeneration gas heater is configured as the outlet of the regeneration gas unit.

[0012] Further, the regeneration gas heater is an electric heater.

[0013] Further, a liquid storage tank is connected to the liquid outlet of the regeneration gas separator.

[0014] Further, a liquid storage tank is connected to the liquid outlet of the raw material gas separator.

[0015] The beneficial effects of the present utility model are:

[0016] (1) In the present utility model, the adjacent molecular sieve dehydration towers are connected in series, and the heat of the molecular sieve drying tower in the cold blow state can be used to initially heat the molecular sieve drying tower in the hot blow state, reducing the energy consumption of the regeneration gas air cooler and the regeneration gas heater during the working process of the energy-saving CNG recycling integrated skid;

[0017] (2) In the energy-saving CNG recovery integrated skid of the present utility model, the system pressure changes with the filling pressure while ensuring the CNG dehydration index, saving the power consumption of the compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the energy-saving CNG recovery integrated skid of the present utility model;

[0019] In the figure, 1 - raw gas separator, 2 - CNG compressor, 3 - first molecular sieve dehydration tower, 4 - second molecular sieve dehydration tower, 5 - third molecular sieve dehydration tower, 6 - regeneration air cooler, 7 - regeneration gas separator, 8 - regeneration gas circulation fan, 9 - regeneration gas heater, 10 - gas dispenser, K1 - first valve, K2 - second valve, K3 - third valve, K4 - fourth valve, K5 - fifth valve, K6 - sixth valve, K7 - seventh valve, K8 - eighth valve, K9 - ninth valve, K10 - tenth valve, K11 - eleventh valve, K12 - twelfth valve, K13 - thirteenth valve, K14 - fourteenth valve, K15 - fifteenth valve, K16 - sixteenth valve. SPECIFIC EMBODIMENTS

[0020] Next, the technical solutions of the present utility model will be clearly and completely described in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0021] Refer to Figure 1 , this embodiment provides an energy-saving CNG recovery integrated skid:

[0022] As Figure 1 shown, an energy-saving CNG recovery integrated skid includes a raw gas separator 1, a CNG compressor 2, a first molecular sieve dehydration tower 3, a second molecular sieve dehydration tower 4, a third molecular sieve dehydration tower 5 and a regeneration gas unit.

[0023] The air inlet of the CNG compressor 2 is connected to the air outlet of the raw gas separator 1.

[0024] The top opening of the first molecular sieve dehydration tower 3 is connected to the outlet of the CNG compressor 2 through the first valve K1. The top opening of the first molecular sieve dehydration tower 3 is connected to the inlet of the regeneration gas unit through the second valve K2. The bottom opening of the first molecular sieve dehydration tower 3 is connected to the top opening of the second molecular sieve dehydration tower 4 through the third valve K3. The bottom opening of the first molecular sieve dehydration tower 3 is connected to the outlet of the regeneration gas unit through the fourth valve K4. The bottom opening of the first molecular sieve dehydration tower 3 is sequentially connected to the gas dispenser 10 through the fifth valve K5 and the sixteenth valve K16.

[0025] The top opening of the second molecular sieve dehydration tower 4 is connected to the outlet of the CNG compressor 2 through the sixth valve K6. The top opening of the second molecular sieve dehydration tower 4 is connected to the inlet of the regeneration gas unit through the seventh valve K7. The bottom opening of the second molecular sieve dehydration tower 4 is connected to the top opening of the third molecular sieve dehydration tower 5 through the eighth valve K8. The bottom opening of the second molecular sieve dehydration tower 4 is connected to the outlet of the regeneration gas unit through the ninth valve K9. The bottom opening of the second molecular sieve dehydration tower 4 is sequentially connected to the gas dispenser 10 through the tenth valve K10 and the sixteenth valve K16.

[0026] The top opening of the third molecular sieve dehydration tower 5 is connected to the outlet of the CNG compressor 2 through the eleventh valve K11. The top opening of the third molecular sieve dehydration tower 5 is connected to the inlet of the regeneration gas unit through the twelfth valve K12. The bottom opening of the third molecular sieve dehydration tower 5 is connected to the top opening of the first molecular sieve dehydration tower 3 through the thirteenth valve K13. The bottom opening of the third molecular sieve dehydration tower 5 is connected to the outlet of the regeneration gas unit through the fourteenth valve K14. The bottom opening of the third molecular sieve dehydration tower 5 is sequentially connected to the gas dispenser 10 through the fifteenth valve K15 and the sixteenth valve K16.

[0027] In this embodiment, the working process of the energy-saving CNG recovery integrated skid is as follows: It is executed in a cycle according to the steps shown in Table 1, where A represents adsorption, H represents hot blow, and C represents cold blow.

[0028] Table 1 Working process of the molecular sieve dehydration tower

[0029]

[0030] In step sequence one, the sixteenth valve K16, the first valve K1, and the fifth valve K5 are opened, the second valve K2, the third valve K3, and the fourth valve K4 are closed, and the first molecular sieve dehydration tower 3 adsorbs natural gas; the sixth valve K6 and the tenth valve K10 are opened, the seventh valve K7, the eighth valve K8, and the ninth valve K9 are closed, and the second molecular sieve dehydration tower 4 adsorbs natural gas; the twelfth valve K12 and the fourteenth valve K14 are opened, the eleventh valve K11, the thirteenth valve K13, and the fifteenth valve K15 are closed, the regeneration gas unit outputs heated regeneration gas, and the third molecular sieve dehydration tower 5 performs hot blow under the action of the regeneration gas.

[0031] In step sequence two, the sixteenth valve K16, the first valve K1, and the fifth valve K5 are opened, the second valve K2, the third valve K3, and the fourth valve K4 are closed, and the first molecular sieve dehydration tower 3 adsorbs natural gas; the seventh valve K7, the eighth valve K8, and the fourteenth valve K14 are opened, the sixth valve K6, the ninth valve K9, the tenth valve K10, the eleventh valve K11, the twelfth valve K12, the thirteenth valve K13, and the fifteenth valve K15 are closed, the regeneration gas unit outputs cooled regeneration gas, and the third molecular sieve dehydration tower 5 performs cold blow under the action of the regeneration gas. The heat from the cold blow of the third molecular sieve dehydration tower 5 performs hot blow on the second molecular sieve dehydration tower 4.

[0032] In step sequence three, the sixteenth valve K16, the first valve K1, and the fifth valve K5 are opened, the second valve K2, the third valve K3, and the fourth valve K4 are closed, and the first molecular sieve dehydration tower 3 adsorbs natural gas; the eleventh valve K11 and the fifteenth valve K15 are opened, the twelfth valve K12, the thirteenth valve K13, and the fourteenth valve K14 are closed, and the third molecular sieve dehydration tower 5 adsorbs natural gas; the seventh valve K7 and the ninth valve K9 are opened, the sixth valve K6, the eighth valve K8, and the tenth valve K10 are closed, the regeneration gas unit outputs heated regeneration gas, and the second molecular sieve dehydration tower 4 performs hot blow under the action of the regeneration gas.

[0033] In step sequence four, the sixteenth valve K16, the eleventh valve K11, and the fifteenth valve K15 are opened, the twelfth valve K12, the thirteenth valve K13, and the fourteenth valve K14 are closed, and the third molecular sieve dehydration tower 5 adsorbs natural gas; the second valve K2, the third valve K3, and the ninth valve K9 are opened, the first valve K1, the fourth valve K4, the fifth valve K5, the sixth valve K6, the seventh valve K7, the eighth valve K8, and the tenth valve K10 are closed, the regeneration gas unit outputs cooled regeneration gas, and the second molecular sieve dehydration tower 4 performs cold blow under the action of the regeneration gas. The heat from the cold blow of the second molecular sieve dehydration tower 4 performs hot blow on the first molecular sieve dehydration tower 3.

[0034] In step 5, the sixteenth valve K16 is opened, the sixth valve K6 and the tenth valve K10 are opened, the seventh valve K7, the eighth valve K8 and the ninth valve K9 are closed, and the second molecular sieve dehydration tower 4 adsorbs natural gas; the eleventh valve K11 and the fifteenth valve K15 are opened, the twelfth valve K12, the thirteenth valve K13 and the fourteenth valve K14 are closed, and the third molecular sieve dehydration tower 5 adsorbs natural gas; the second valve K2 and the fourth valve K4 are opened, the first valve K1, the third valve K3 and the fifth valve K5 are closed, and the regeneration gas unit outputs heated regeneration gas, and the first molecular sieve dehydration tower 3 is thermally blown under the action of the regeneration gas.

[0035] In step 6, the sixteenth valve K16 is opened, the sixth valve K6 and the tenth valve K10 are opened, the seventh valve K7, the eighth valve K8 and the ninth valve K9 are closed, and the second molecular sieve dehydration tower 4 adsorbs natural gas; the fourth valve K4, the twelfth valve K12 and the thirteenth valve K13 are opened, the first valve K1, the second valve K2, the third valve K3, the fifth valve K5, the eleventh valve K11, the fourteenth valve K14 and the fifteenth valve K15 are closed, and the regeneration gas unit outputs cooled regeneration gas, and the first molecular sieve dehydration tower 3 is cold blown under the action of the regeneration gas, and the heat of the cold blow of the first molecular sieve dehydration tower 3 thermally blows the third molecular sieve dehydration tower 5.

[0036] In this embodiment, the sixteenth valve K16 is opened when the energy-saving CNG recovery integrated skid starts to operate and closed when the energy-saving CNG recovery integrated skid ends to operate.

[0037] In this embodiment, a predetermined amount of regeneration gas is pre-added to the energy-saving CNG recovery integrated skid, and the regeneration gas is recycled during the operation of the energy-saving CNG recovery integrated skid, reducing the consumption of the regeneration gas. When maintenance and other operations need to be performed on the energy-saving CNG recovery integrated skid, the regeneration gas in the energy-saving CNG recovery integrated skid is discharged.

[0038] The duration of each step is determined according to the parameters of equipment such as the first molecular sieve dehydration tower 3, the second molecular sieve dehydration tower 4 and the third molecular sieve dehydration tower 5. For example, the duration of each step is 3 hours.

[0039] In some embodiments, the first valve K1, the second valve K2, the third valve K3, the fourth valve K4, the fifth valve K5, the sixth valve K6, the seventh valve K7, the eighth valve K8, the ninth valve K9, the tenth valve, the eleventh valve, the twelfth valve K12, the thirteenth valve K13, the fourteenth valve K14, the fifteenth valve K15 and the sixteenth valve K16 are all program-controlled valves.

[0040] In some embodiments, the regeneration gas unit includes a regeneration gas air cooler 6, a regeneration gas separator 7, a regeneration gas circulation fan 8, and a regeneration gas heater 9 connected in series in sequence. The inlet of the regeneration gas air cooler 6 is configured as the inlet of the regeneration gas unit, and the outlet of the regeneration gas heater 9 is configured as the outlet of the regeneration gas unit. The regeneration gas air cooler 6 is used to cool the regeneration gas, the regeneration gas separator 7 is used to separate gas and liquid from the regeneration gas, and the regeneration gas heater 9 is used to heat the regeneration gas.

[0041] In some embodiments, the regeneration gas heater 9 is an electric heater.

[0042] In some embodiments, a liquid storage tank is connected to the liquid outlet of the regeneration gas separator 7, and this liquid storage tank is used to store the liquid separated from the regeneration gas by the regeneration gas separator 7.

[0043] In some embodiments, a liquid storage tank is connected to the liquid outlet of the raw material gas separator 1, and this liquid storage tank is used to store the liquid separated from the raw material gas in the raw material gas separator.

[0044] The above are only the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications, and environments, and can be changed within the scope of the concept described herein through the above teachings or the technology or knowledge in related fields. And any changes and modifications made by those skilled in the art without departing from the spirit and scope of the present invention shall fall within the protection scope of the appended claims of the present invention.

Claims

1. An energy-saving CNG recovery integrated skid, characterized in that, It includes a raw gas separator, a CNG compressor, a first molecular sieve dehydration tower, a second molecular sieve dehydration tower, a third molecular sieve dehydration tower and a regeneration gas unit; The inlet of the CNG compressor is connected to the outlet of the raw gas separator; The top opening of the first molecular sieve dehydration tower is connected to the outlet of the CNG compressor through a first valve, the top opening of the first molecular sieve dehydration tower is connected to the inlet of the regeneration gas unit through a second valve, the bottom opening of the first molecular sieve dehydration tower is connected to the top opening of the second molecular sieve dehydration tower through a third valve, the bottom opening of the first molecular sieve dehydration tower is connected to the outlet of the regeneration gas unit through a fourth valve, and the bottom opening of the first molecular sieve dehydration tower is connected to a dispenser through a fifth valve and a sixteenth valve in sequence; The top opening of the second molecular sieve dehydration tower is connected to the outlet of the CNG compressor through a sixth valve, the top opening of the second molecular sieve dehydration tower is connected to the inlet of the regeneration gas unit through a seventh valve, the bottom opening of the second molecular sieve dehydration tower is connected to the top opening of the third molecular sieve dehydration tower through an eighth valve, the bottom opening of the second molecular sieve dehydration tower is connected to the outlet of the regeneration gas unit through a ninth valve, and the bottom opening of the second molecular sieve dehydration tower is connected to a dispenser through a tenth valve and a sixteenth valve in sequence; The top opening of the third molecular sieve dehydration tower is connected to the outlet of the CNG compressor through an eleventh valve, the top opening of the third molecular sieve dehydration tower is connected to the inlet of the regeneration gas unit through a twelfth valve, the bottom opening of the third molecular sieve dehydration tower is connected to the top opening of the first molecular sieve dehydration tower through a thirteenth valve, the bottom opening of the third molecular sieve dehydration tower is connected to the outlet of the regeneration gas unit through a fourteenth valve, and the bottom opening of the third molecular sieve dehydration tower is connected to a dispenser through a fifteenth valve and a sixteenth valve in sequence.

2. An energy-saving CNG recovery integrated skid according to claim 1, characterized in that, The first valve, the second valve, the third valve, the fourth valve, the fifth valve, the sixth valve, the seventh valve, the eighth valve, the ninth valve, the tenth valve, the eleventh valve, the twelfth valve, the thirteenth valve, the fourteenth valve, the fifteenth valve and the sixteenth valve are all program-controlled valves.

3. An energy-saving CNG recovery integrated skid according to claim 1, characterized in that The regeneration gas unit includes a regeneration gas air cooler, a regeneration gas separator, a regeneration gas circulation fan and a regeneration gas heater connected in series in sequence. The inlet of the regeneration gas air cooler is configured as the inlet of the regeneration gas unit, and the outlet of the regeneration gas heater is configured as the outlet of the regeneration gas unit.

4. The energy-saving CNG recovery integrated skid according to claim 3, characterized in that, The regeneration gas heater is an electric heater.

5. An energy-saving CNG recovery integrated skid according to claim 3, characterized in that, A liquid storage tank is connected to the liquid outlet of the regeneration gas separator.

6. The energy-saving CNG recovery integrated skid according to claim 1, wherein, A liquid storage tank is connected to the liquid outlet of the raw gas separator.

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